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Diffstat (limited to 'drivers/ide/ide-tape.c')
| -rw-r--r-- | drivers/ide/ide-tape.c | 4937 |
1 files changed, 4937 insertions, 0 deletions
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c new file mode 100644 index 00000000000..48254485498 --- /dev/null +++ b/drivers/ide/ide-tape.c @@ -0,0 +1,4937 @@ +/* + * linux/drivers/ide/ide-tape.c Version 1.19 Nov, 2003 + * + * Copyright (C) 1995 - 1999 Gadi Oxman <gadio@netvision.net.il> + * + * $Header$ + * + * This driver was constructed as a student project in the software laboratory + * of the faculty of electrical engineering in the Technion - Israel's + * Institute Of Technology, with the guide of Avner Lottem and Dr. Ilana David. + * + * It is hereby placed under the terms of the GNU general public license. + * (See linux/COPYING). + */ + +/* + * IDE ATAPI streaming tape driver. + * + * This driver is a part of the Linux ide driver and works in co-operation + * with linux/drivers/block/ide.c. + * + * The driver, in co-operation with ide.c, basically traverses the + * request-list for the block device interface. The character device + * interface, on the other hand, creates new requests, adds them + * to the request-list of the block device, and waits for their completion. + * + * Pipelined operation mode is now supported on both reads and writes. + * + * The block device major and minor numbers are determined from the + * tape's relative position in the ide interfaces, as explained in ide.c. + * + * The character device interface consists of the following devices: + * + * ht0 major 37, minor 0 first IDE tape, rewind on close. + * ht1 major 37, minor 1 second IDE tape, rewind on close. + * ... + * nht0 major 37, minor 128 first IDE tape, no rewind on close. + * nht1 major 37, minor 129 second IDE tape, no rewind on close. + * ... + * + * Run linux/scripts/MAKEDEV.ide to create the above entries. + * + * The general magnetic tape commands compatible interface, as defined by + * include/linux/mtio.h, is accessible through the character device. + * + * General ide driver configuration options, such as the interrupt-unmask + * flag, can be configured by issuing an ioctl to the block device interface, + * as any other ide device. + * + * Our own ide-tape ioctl's can be issued to either the block device or + * the character device interface. + * + * Maximal throughput with minimal bus load will usually be achieved in the + * following scenario: + * + * 1. ide-tape is operating in the pipelined operation mode. + * 2. No buffering is performed by the user backup program. + * + * Testing was done with a 2 GB CONNER CTMA 4000 IDE ATAPI Streaming Tape Drive. + * + * Ver 0.1 Nov 1 95 Pre-working code :-) + * Ver 0.2 Nov 23 95 A short backup (few megabytes) and restore procedure + * was successful ! (Using tar cvf ... on the block + * device interface). + * A longer backup resulted in major swapping, bad + * overall Linux performance and eventually failed as + * we received non serial read-ahead requests from the + * buffer cache. + * Ver 0.3 Nov 28 95 Long backups are now possible, thanks to the + * character device interface. Linux's responsiveness + * and performance doesn't seem to be much affected + * from the background backup procedure. + * Some general mtio.h magnetic tape operations are + * now supported by our character device. As a result, + * popular tape utilities are starting to work with + * ide tapes :-) + * The following configurations were tested: + * 1. An IDE ATAPI TAPE shares the same interface + * and irq with an IDE ATAPI CDROM. + * 2. An IDE ATAPI TAPE shares the same interface + * and irq with a normal IDE disk. + * Both configurations seemed to work just fine ! + * However, to be on the safe side, it is meanwhile + * recommended to give the IDE TAPE its own interface + * and irq. + * The one thing which needs to be done here is to + * add a "request postpone" feature to ide.c, + * so that we won't have to wait for the tape to finish + * performing a long media access (DSC) request (such + * as a rewind) before we can access the other device + * on the same interface. This effect doesn't disturb + * normal operation most of the time because read/write + * requests are relatively fast, and once we are + * performing one tape r/w request, a lot of requests + * from the other device can be queued and ide.c will + * service all of them after this single tape request. + * Ver 1.0 Dec 11 95 Integrated into Linux 1.3.46 development tree. + * On each read / write request, we now ask the drive + * if we can transfer a constant number of bytes + * (a parameter of the drive) only to its buffers, + * without causing actual media access. If we can't, + * we just wait until we can by polling the DSC bit. + * This ensures that while we are not transferring + * more bytes than the constant referred to above, the + * interrupt latency will not become too high and + * we won't cause an interrupt timeout, as happened + * occasionally in the previous version. + * While polling for DSC, the current request is + * postponed and ide.c is free to handle requests from + * the other device. This is handled transparently to + * ide.c. The hwgroup locking method which was used + * in the previous version was removed. + * Use of new general features which are provided by + * ide.c for use with atapi devices. + * (Programming done by Mark Lord) + * Few potential bug fixes (Again, suggested by Mark) + * Single character device data transfers are now + * not limited in size, as they were before. + * We are asking the tape about its recommended + * transfer unit and send a larger data transfer + * as several transfers of the above size. + * For best results, use an integral number of this + * basic unit (which is shown during driver + * initialization). I will soon add an ioctl to get + * this important parameter. + * Our data transfer buffer is allocated on startup, + * rather than before each data transfer. This should + * ensure that we will indeed have a data buffer. + * Ver 1.1 Dec 14 95 Fixed random problems which occurred when the tape + * shared an interface with another device. + * (poll_for_dsc was a complete mess). + * Removed some old (non-active) code which had + * to do with supporting buffer cache originated + * requests. + * The block device interface can now be opened, so + * that general ide driver features like the unmask + * interrupts flag can be selected with an ioctl. + * This is the only use of the block device interface. + * New fast pipelined operation mode (currently only on + * writes). When using the pipelined mode, the + * throughput can potentially reach the maximum + * tape supported throughput, regardless of the + * user backup program. On my tape drive, it sometimes + * boosted performance by a factor of 2. Pipelined + * mode is enabled by default, but since it has a few + * downfalls as well, you may want to disable it. + * A short explanation of the pipelined operation mode + * is available below. + * Ver 1.2 Jan 1 96 Eliminated pipelined mode race condition. + * Added pipeline read mode. As a result, restores + * are now as fast as backups. + * Optimized shared interface behavior. The new behavior + * typically results in better IDE bus efficiency and + * higher tape throughput. + * Pre-calculation of the expected read/write request + * service time, based on the tape's parameters. In + * the pipelined operation mode, this allows us to + * adjust our polling frequency to a much lower value, + * and thus to dramatically reduce our load on Linux, + * without any decrease in performance. + * Implemented additional mtio.h operations. + * The recommended user block size is returned by + * the MTIOCGET ioctl. + * Additional minor changes. + * Ver 1.3 Feb 9 96 Fixed pipelined read mode bug which prevented the + * use of some block sizes during a restore procedure. + * The character device interface will now present a + * continuous view of the media - any mix of block sizes + * during a backup/restore procedure is supported. The + * driver will buffer the requests internally and + * convert them to the tape's recommended transfer + * unit, making performance almost independent of the + * chosen user block size. + * Some improvements in error recovery. + * By cooperating with ide-dma.c, bus mastering DMA can + * now sometimes be used with IDE tape drives as well. + * Bus mastering DMA has the potential to dramatically + * reduce the CPU's overhead when accessing the device, + * and can be enabled by using hdparm -d1 on the tape's + * block device interface. For more info, read the + * comments in ide-dma.c. + * Ver 1.4 Mar 13 96 Fixed serialize support. + * Ver 1.5 Apr 12 96 Fixed shared interface operation, broken in 1.3.85. + * Fixed pipelined read mode inefficiency. + * Fixed nasty null dereferencing bug. + * Ver 1.6 Aug 16 96 Fixed FPU usage in the driver. + * Fixed end of media bug. + * Ver 1.7 Sep 10 96 Minor changes for the CONNER CTT8000-A model. + * Ver 1.8 Sep 26 96 Attempt to find a better balance between good + * interactive response and high system throughput. + * Ver 1.9 Nov 5 96 Automatically cross encountered filemarks rather + * than requiring an explicit FSF command. + * Abort pending requests at end of media. + * MTTELL was sometimes returning incorrect results. + * Return the real block size in the MTIOCGET ioctl. + * Some error recovery bug fixes. + * Ver 1.10 Nov 5 96 Major reorganization. + * Reduced CPU overhead a bit by eliminating internal + * bounce buffers. + * Added module support. + * Added multiple tape drives support. + * Added partition support. + * Rewrote DSC handling. + * Some portability fixes. + * Removed ide-tape.h. + * Additional minor changes. + * Ver 1.11 Dec 2 96 Bug fix in previous DSC timeout handling. + * Use ide_stall_queue() for DSC overlap. + * Use the maximum speed rather than the current speed + * to compute the request service time. + * Ver 1.12 Dec 7 97 Fix random memory overwriting and/or last block data + * corruption, which could occur if the total number + * of bytes written to the tape was not an integral + * number of tape blocks. + * Add support for INTERRUPT DRQ devices. + * Ver 1.13 Jan 2 98 Add "speed == 0" work-around for HP COLORADO 5GB + * Ver 1.14 Dec 30 98 Partial fixes for the Sony/AIWA tape drives. + * Replace cli()/sti() with hwgroup spinlocks. + * Ver 1.15 Mar 25 99 Fix SMP race condition by replacing hwgroup + * spinlock with private per-tape spinlock. + * Ver 1.16 Sep 1 99 Add OnStream tape support. + * Abort read pipeline on EOD. + * Wait for the tape to become ready in case it returns + * "in the process of becoming ready" on open(). + * Fix zero padding of the last written block in + * case the tape block size is larger than PAGE_SIZE. + * Decrease the default disconnection time to tn. + * Ver 1.16e Oct 3 99 Minor fixes. + * Ver 1.16e1 Oct 13 99 Patches by Arnold Niessen, + * niessen@iae.nl / arnold.niessen@philips.com + * GO-1) Undefined code in idetape_read_position + * according to Gadi's email + * AJN-1) Minor fix asc == 11 should be asc == 0x11 + * in idetape_issue_packet_command (did effect + * debugging output only) + * AJN-2) Added more debugging output, and + * added ide-tape: where missing. I would also + * like to add tape->name where possible + * AJN-3) Added different debug_level's + * via /proc/ide/hdc/settings + * "debug_level" determines amount of debugging output; + * can be changed using /proc/ide/hdx/settings + * 0 : almost no debugging output + * 1 : 0+output errors only + * 2 : 1+output all sensekey/asc + * 3 : 2+follow all chrdev related procedures + * 4 : 3+follow all procedures + * 5 : 4+include pc_stack rq_stack info + * 6 : 5+USE_COUNT updates + * AJN-4) Fixed timeout for retension in idetape_queue_pc_tail + * from 5 to 10 minutes + * AJN-5) Changed maximum number of blocks to skip when + * reading tapes with multiple consecutive write + * errors from 100 to 1000 in idetape_get_logical_blk + * Proposed changes to code: + * 1) output "logical_blk_num" via /proc + * 2) output "current_operation" via /proc + * 3) Either solve or document the fact that `mt rewind' is + * required after reading from /dev/nhtx to be + * able to rmmod the idetape module; + * Also, sometimes an application finishes but the + * device remains `busy' for some time. Same cause ? + * Proposed changes to release-notes: + * 4) write a simple `quickstart' section in the + * release notes; I volunteer if you don't want to + * 5) include a pointer to video4linux in the doc + * to stimulate video applications + * 6) release notes lines 331 and 362: explain what happens + * if the application data rate is higher than 1100 KB/s; + * similar approach to lower-than-500 kB/s ? + * 7) 6.6 Comparison; wouldn't it be better to allow different + * strategies for read and write ? + * Wouldn't it be better to control the tape buffer + * contents instead of the bandwidth ? + * 8) line 536: replace will by would (if I understand + * this section correctly, a hypothetical and unwanted situation + * is being described) + * Ver 1.16f Dec 15 99 Change place of the secondary OnStream header frames. + * Ver 1.17 Nov 2000 / Jan 2001 Marcel Mol, marcel@mesa.nl + * - Add idetape_onstream_mode_sense_tape_parameter_page + * function to get tape capacity in frames: tape->capacity. + * - Add support for DI-50 drives( or any DI- drive). + * - 'workaround' for read error/blank block around block 3000. + * - Implement Early warning for end of media for Onstream. + * - Cosmetic code changes for readability. + * - Idetape_position_tape should not use SKIP bit during + * Onstream read recovery. + * - Add capacity, logical_blk_num and first/last_frame_position + * to /proc/ide/hd?/settings. + * - Module use count was gone in the Linux 2.4 driver. + * Ver 1.17a Apr 2001 Willem Riede osst@riede.org + * - Get drive's actual block size from mode sense block descriptor + * - Limit size of pipeline + * Ver 1.17b Oct 2002 Alan Stern <stern@rowland.harvard.edu> + * Changed IDETAPE_MIN_PIPELINE_STAGES to 1 and actually used + * it in the code! + * Actually removed aborted stages in idetape_abort_pipeline + * instead of just changing the command code. + * Made the transfer byte count for Request Sense equal to the + * actual length of the data transfer. + * Changed handling of partial data transfers: they do not + * cause DMA errors. + * Moved initiation of DMA transfers to the correct place. + * Removed reference to unallocated memory. + * Made __idetape_discard_read_pipeline return the number of + * sectors skipped, not the number of stages. + * Replaced errant kfree() calls with __idetape_kfree_stage(). + * Fixed off-by-one error in testing the pipeline length. + * Fixed handling of filemarks in the read pipeline. + * Small code optimization for MTBSF and MTBSFM ioctls. + * Don't try to unlock the door during device close if is + * already unlocked! + * Cosmetic fixes to miscellaneous debugging output messages. + * Set the minimum /proc/ide/hd?/settings values for "pipeline", + * "pipeline_min", and "pipeline_max" to 1. + * + * Here are some words from the first releases of hd.c, which are quoted + * in ide.c and apply here as well: + * + * | Special care is recommended. Have Fun! + * + */ + +/* + * An overview of the pipelined operation mode. + * + * In the pipelined write mode, we will usually just add requests to our + * pipeline and return immediately, before we even start to service them. The + * user program will then have enough time to prepare the next request while + * we are still busy servicing previous requests. In the pipelined read mode, + * the situation is similar - we add read-ahead requests into the pipeline, + * before the user even requested them. + * + * The pipeline can be viewed as a "safety net" which will be activated when + * the system load is high and prevents the user backup program from keeping up + * with the current tape speed. At this point, the pipeline will get + * shorter and shorter but the tape will still be streaming at the same speed. + * Assuming we have enough pipeline stages, the system load will hopefully + * decrease before the pipeline is completely empty, and the backup program + * will be able to "catch up" and refill the pipeline again. + * + * When using the pipelined mode, it would be best to disable any type of + * buffering done by the user program, as ide-tape already provides all the + * benefits in the kernel, where it can be done in a more efficient way. + * As we will usually not block the user program on a request, the most + * efficient user code will then be a simple read-write-read-... cycle. + * Any additional logic will usually just slow down the backup process. + * + * Using the pipelined mode, I get a constant over 400 KBps throughput, + * which seems to be the maximum throughput supported by my tape. + * + * However, there are some downfalls: + * + * 1. We use memory (for data buffers) in proportional to the number + * of pipeline stages (each stage is about 26 KB with my tape). + * 2. In the pipelined write mode, we cheat and postpone error codes + * to the user task. In read mode, the actual tape position + * will be a bit further than the last requested block. + * + * Concerning (1): + * + * 1. We allocate stages dynamically only when we need them. When + * we don't need them, we don't consume additional memory. In + * case we can't allocate stages, we just manage without them + * (at the expense of decreased throughput) so when Linux is + * tight in memory, we will not pose additional difficulties. + * + * 2. The maximum number of stages (which is, in fact, the maximum + * amount of memory) which we allocate is limited by the compile + * time parameter IDETAPE_MAX_PIPELINE_STAGES. + * + * 3. The maximum number of stages is a controlled parameter - We + * don't start from the user defined maximum number of stages + * but from the lower IDETAPE_MIN_PIPELINE_STAGES (again, we + * will not even allocate this amount of stages if the user + * program can't handle the speed). We then implement a feedback + * loop which checks if the pipeline is empty, and if it is, we + * increase the maximum number of stages as necessary until we + * reach the optimum value which just manages to keep the tape + * busy with minimum allocated memory or until we reach + * IDETAPE_MAX_PIPELINE_STAGES. + * + * Concerning (2): + * + * In pipelined write mode, ide-tape can not return accurate error codes + * to the user program since we usually just add the request to the + * pipeline without waiting for it to be serviced. In case an error + * occurs, I will report it on the next user request. + * + * In the pipelined read mode, subsequent read requests or forward + * filemark spacing will perform correctly, as we preserve all blocks + * and filemarks which we encountered during our excess read-ahead. + * + * For accurate tape positioning and error reporting, disabling + * pipelined mode might be the best option. + * + * You can enable/disable/tune the pipelined operation mode by adjusting + * the compile time parameters below. + */ + +/* + * Possible improvements. + * + * 1. Support for the ATAPI overlap protocol. + * + * In order to maximize bus throughput, we currently use the DSC + * overlap method which enables ide.c to service requests from the + * other device while the tape is busy executing a command. The + * DSC overlap method involves polling the tape's status register + * for the DSC bit, and servicing the other device while the tape + * isn't ready. + * + * In the current QIC development standard (December 1995), + * it is recommended that new tape drives will *in addition* + * implement the ATAPI overlap protocol, which is used for the + * same purpose - efficient use of the IDE bus, but is interrupt + * driven and thus has much less CPU overhead. + * + * ATAPI overlap is likely to be supported in most new ATAPI + * devices, including new ATAPI cdroms, and thus provides us + * a method by which we can achieve higher throughput when + * sharing a (fast) ATA-2 disk with any (slow) new ATAPI device. + */ + +#define IDETAPE_VERSION "1.19" + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/string.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/major.h> +#include <linux/devfs_fs_kernel.h> +#include <linux/errno.h> +#include <linux/genhd.h> +#include <linux/slab.h> +#include <linux/pci.h> +#include <linux/ide.h> +#include <linux/smp_lock.h> +#include <linux/completion.h> +#include <linux/bitops.h> + +#include <asm/byteorder.h> +#include <asm/irq.h> +#include <asm/uaccess.h> +#include <asm/io.h> +#include <asm/unaligned.h> + +/* + * partition + */ +typedef struct os_partition_s { + __u8 partition_num; + __u8 par_desc_ver; + __u16 wrt_pass_cntr; + __u32 first_frame_addr; + __u32 last_frame_addr; + __u32 eod_frame_addr; +} os_partition_t; + +/* + * DAT entry + */ +typedef struct os_dat_entry_s { + __u32 blk_sz; + __u16 blk_cnt; + __u8 flags; + __u8 reserved; +} os_dat_entry_t; + +/* + * DAT + */ +#define OS_DAT_FLAGS_DATA (0xc) +#define OS_DAT_FLAGS_MARK (0x1) + +typedef struct os_dat_s { + __u8 dat_sz; + __u8 reserved1; + __u8 entry_cnt; + __u8 reserved3; + os_dat_entry_t dat_list[16]; +} os_dat_t; + +#include <linux/mtio.h> + +/**************************** Tunable parameters *****************************/ + + +/* + * Pipelined mode parameters. + * + * We try to use the minimum number of stages which is enough to + * keep the tape constantly streaming. To accomplish that, we implement + * a feedback loop around the maximum number of stages: + * + * We start from MIN maximum stages (we will not even use MIN stages + * if we don't need them), increment it by RATE*(MAX-MIN) + * whenever we sense that the pipeline is empty, until we reach + * the optimum value or until we reach MAX. + * + * Setting the following parameter to 0 is illegal: the pipelined mode + * cannot be disabled (calculate_speeds() divides by tape->max_stages.) + */ +#define IDETAPE_MIN_PIPELINE_STAGES 1 +#define IDETAPE_MAX_PIPELINE_STAGES 400 +#define IDETAPE_INCREASE_STAGES_RATE 20 + +/* + * The following are used to debug the driver: + * + * Setting IDETAPE_DEBUG_INFO to 1 will report device capabilities. + * Setting IDETAPE_DEBUG_LOG to 1 will log driver flow control. + * Setting IDETAPE_DEBUG_BUGS to 1 will enable self-sanity checks in + * some places. + * + * Setting them to 0 will restore normal operation mode: + * + * 1. Disable logging normal successful operations. + * 2. Disable self-sanity checks. + * 3. Errors will still be logged, of course. + * + * All the #if DEBUG code will be removed some day, when the driver + * is verified to be stable enough. This will make it much more + * esthetic. + */ +#define IDETAPE_DEBUG_INFO 0 +#define IDETAPE_DEBUG_LOG 0 +#define IDETAPE_DEBUG_BUGS 1 + +/* + * After each failed packet command we issue a request sense command + * and retry the packet command IDETAPE_MAX_PC_RETRIES times. + * + * Setting IDETAPE_MAX_PC_RETRIES to 0 will disable retries. + */ +#define IDETAPE_MAX_PC_RETRIES 3 + +/* + * With each packet command, we allocate a buffer of + * IDETAPE_PC_BUFFER_SIZE bytes. This is used for several packet + * commands (Not for READ/WRITE commands). + */ +#define IDETAPE_PC_BUFFER_SIZE 256 + +/* + * In various places in the driver, we need to allocate storage + * for packet commands and requests, which will remain valid while + * we leave the driver to wait for an interrupt or a timeout event. + */ +#define IDETAPE_PC_STACK (10 + IDETAPE_MAX_PC_RETRIES) + +/* + * Some drives (for example, Seagate STT3401A Travan) require a very long + * timeout, because they don't return an interrupt or clear their busy bit + * until after the command completes (even retension commands). + */ +#define IDETAPE_WAIT_CMD (900*HZ) + +/* + * The following parameter is used to select the point in the internal + * tape fifo in which we will start to refill the buffer. Decreasing + * the following parameter will improve the system's latency and + * interactive response, while using a high value might improve sytem + * throughput. + */ +#define IDETAPE_FIFO_THRESHOLD 2 + +/* + * DSC polling parameters. + * + * Polling for DSC (a single bit in the status register) is a very + * important function in ide-tape. There are two cases in which we + * poll for DSC: + * + * 1. Before a read/write packet command, to ensure that we + * can transfer data from/to the tape's data buffers, without + * causing an actual media access. In case the tape is not + * ready yet, we take out our request from the device + * request queue, so that ide.c will service requests from + * the other device on the same interface meanwhile. + * + * 2. After the successful initialization of a "media access + * packet command", which is a command which can take a long + * time to complete (it can be several seconds or even an hour). + * + * Again, we postpone our request in the middle to free the bus + * for the other device. The polling frequency here should be + * lower than the read/write frequency since those media access + * commands are slow. We start from a "fast" frequency - + * IDETAPE_DSC_MA_FAST (one second), and if we don't receive DSC + * after IDETAPE_DSC_MA_THRESHOLD (5 minutes), we switch it to a + * lower frequency - IDETAPE_DSC_MA_SLOW (1 minute). + * + * We also set a timeout for the timer, in case something goes wrong. + * The timeout should be longer then the maximum execution time of a + * tape operation. + */ + +/* + * DSC timings. + */ +#define IDETAPE_DSC_RW_MIN 5*HZ/100 /* 50 msec */ +#define IDETAPE_DSC_RW_MAX 40*HZ/100 /* 400 msec */ +#define IDETAPE_DSC_RW_TIMEOUT 2*60*HZ /* 2 minutes */ +#define IDETAPE_DSC_MA_FAST 2*HZ /* 2 seconds */ +#define IDETAPE_DSC_MA_THRESHOLD 5*60*HZ /* 5 minutes */ +#define IDETAPE_DSC_MA_SLOW 30*HZ /* 30 seconds */ +#define IDETAPE_DSC_MA_TIMEOUT 2*60*60*HZ /* 2 hours */ + +/*************************** End of tunable parameters ***********************/ + +/* + * Debugging/Performance analysis + * + * I/O trace support + */ +#define USE_IOTRACE 0 +#if USE_IOTRACE +#include <linux/io_trace.h> +#define IO_IDETAPE_FIFO 500 +#endif + +/* + * Read/Write error simulation + */ +#define SIMULATE_ERRORS 0 + +/* + * For general magnetic tape device compatibility. + */ +typedef enum { + idetape_direction_none, + idetape_direction_read, + idetape_direction_write +} idetape_chrdev_direction_t; + +struct idetape_bh { + unsigned short b_size; + atomic_t b_count; + struct idetape_bh *b_reqnext; + char *b_data; +}; + +/* + * Our view of a packet command. + */ +typedef struct idetape_packet_command_s { + u8 c[12]; /* Actual packet bytes */ + int retries; /* On each retry, we increment retries */ + int error; /* Error code */ + int request_transfer; /* Bytes to transfer */ + int actually_transferred; /* Bytes actually transferred */ + int buffer_size; /* Size of our data buffer */ + struct idetape_bh *bh; + char *b_data; + int b_count; + u8 *buffer; /* Data buffer */ + u8 *current_position; /* Pointer into the above buffer */ + ide_startstop_t (*callback) (ide_drive_t *); /* Called when this packet command is completed */ + u8 pc_buffer[IDETAPE_PC_BUFFER_SIZE]; /* Temporary buffer */ + unsigned long flags; /* Status/Action bit flags: long for set_bit */ +} idetape_pc_t; + +/* + * Packet command flag bits. + */ +/* Set when an error is considered normal - We won't retry */ +#define PC_ABORT 0 +/* 1 When polling for DSC on a media access command */ +#define PC_WAIT_FOR_DSC 1 +/* 1 when we prefer to use DMA if possible */ +#define PC_DMA_RECOMMENDED 2 +/* 1 while DMA in progress */ +#define PC_DMA_IN_PROGRESS 3 +/* 1 when encountered problem during DMA */ +#define PC_DMA_ERROR 4 +/* Data direction */ +#define PC_WRITING 5 + +/* + * Capabilities and Mechanical Status Page + */ +typedef struct { + unsigned page_code :6; /* Page code - Should be 0x2a */ + __u8 reserved0_6 :1; + __u8 ps :1; /* parameters saveable */ + __u8 page_length; /* Page Length - Should be 0x12 */ + __u8 reserved2, reserved3; + unsigned ro :1; /* Read Only Mode */ + unsigned reserved4_1234 :4; + unsigned sprev :1; /* Supports SPACE in the reverse direction */ + unsigned reserved4_67 :2; + unsigned reserved5_012 :3; + unsigned efmt :1; /* Supports ERASE command initiated formatting */ + unsigned reserved5_4 :1; + unsigned qfa :1; /* Supports the QFA two partition formats */ + unsigned reserved5_67 :2; + unsigned lock :1; /* Supports locking the volume */ + unsigned locked :1; /* The volume is locked */ + unsigned prevent :1; /* The device defaults in the prevent state after power up */ + unsigned eject :1; /* The device can eject the volume */ + __u8 disconnect :1; /* The device can break request > ctl */ + __u8 reserved6_5 :1; + unsigned ecc :1; /* Supports error correction */ + unsigned cmprs :1; /* Supports data compression */ + unsigned reserved7_0 :1; + unsigned blk512 :1; /* Supports 512 bytes block size */ + unsigned blk1024 :1; /* Supports 1024 bytes block size */ + unsigned reserved7_3_6 :4; + unsigned blk32768 :1; /* slowb - the device restricts the byte count for PIO */ + /* transfers for slow buffer memory ??? */ + /* Also 32768 block size in some cases */ + __u16 max_speed; /* Maximum speed supported in KBps */ + __u8 reserved10, reserved11; + __u16 ctl; /* Continuous Transfer Limit in blocks */ + __u16 speed; /* Current Speed, in KBps */ + __u16 buffer_size; /* Buffer Size, in 512 bytes */ + __u8 reserved18, reserved19; +} idetape_capabilities_page_t; + +/* + * Block Size Page + */ +typedef struct { + unsigned page_code :6; /* Page code - Should be 0x30 */ + unsigned reserved1_6 :1; + unsigned ps :1; + __u8 page_length; /* Page Length - Should be 2 */ + __u8 reserved2; + unsigned play32 :1; + unsigned play32_5 :1; + unsigned reserved2_23 :2; + unsigned record32 :1; + unsigned record32_5 :1; + unsigned reserved2_6 :1; + unsigned one :1; +} idetape_block_size_page_t; + +/* + * A pipeline stage. + */ +typedef struct idetape_stage_s { + struct request rq; /* The corresponding request */ + struct idetape_bh *bh; /* The data buffers */ + struct idetape_stage_s *next; /* Pointer to the next stage */ +} idetape_stage_t; + +/* + * REQUEST SENSE packet command result - Data Format. + */ +typedef struct { + unsigned error_code :7; /* Current of deferred errors */ + unsigned valid :1; /* The information field conforms to QIC-157C */ + __u8 reserved1 :8; /* Segment Number - Reserved */ + unsigned sense_key :4; /* Sense Key */ + unsigned reserved2_4 :1; /* Reserved */ + unsigned ili :1; /* Incorrect Length Indicator */ + unsigned eom :1; /* End Of Medium */ + unsigned filemark :1; /* Filemark */ + __u32 information __attribute__ ((packed)); + __u8 asl; /* Additional sense length (n-7) */ + __u32 command_specific; /* Additional command specific information */ + __u8 asc; /* Additional Sense Code */ + __u8 ascq; /* Additional Sense Code Qualifier */ + __u8 replaceable_unit_code; /* Field Replaceable Unit Code */ + unsigned sk_specific1 :7; /* Sense Key Specific */ + unsigned sksv :1; /* Sense Key Specific information is valid */ + __u8 sk_specific2; /* Sense Key Specific */ + __u8 sk_specific3; /* Sense Key Specific */ + __u8 pad[2]; /* Padding to 20 bytes */ +} idetape_request_sense_result_t; + + +/* + * Most of our global data which we need to save even as we leave the + * driver due to an interrupt or a timer event is stored in a variable + * of type idetape_tape_t, defined below. + */ +typedef struct ide_tape_obj { + ide_drive_t *drive; + ide_driver_t *driver; + struct gendisk *disk; + struct kref kref; + + /* + * Since a typical character device operation requires more + * than one packet command, we provide here enough memory + * for the maximum of interconnected packet commands. + * The packet commands are stored in the circular array pc_stack. + * pc_stack_index points to the last used entry, and warps around + * to the start when we get to the last array entry. + * + * pc points to the current processed packet command. + * + * failed_pc points to the last failed packet command, or contains + * NULL if we do not need to retry any packet command. This is + * required since an additional packet command is needed before the + * retry, to get detailed information on what went wrong. + */ + /* Current packet command */ + idetape_pc_t *pc; + /* Last failed packet command */ + idetape_pc_t *failed_pc; + /* Packet command stack */ + idetape_pc_t pc_stack[IDETAPE_PC_STACK]; + /* Next free packet command storage space */ + int pc_stack_index; + struct request rq_stack[IDETAPE_PC_STACK]; + /* We implement a circular array */ + int rq_stack_index; + + /* + * DSC polling variables. + * + * While polling for DSC we use postponed_rq to postpone the + * current request so that ide.c will be able to service + * pending requests on the other device. Note that at most + * we will have only one DSC (usually data transfer) request + * in the device request queue. Additional requests can be + * queued in our internal pipeline, but they will be visible + * to ide.c only one at a time. + */ + struct request *postponed_rq; + /* The time in which we started polling for DSC */ + unsigned long dsc_polling_start; + /* Timer used to poll for dsc */ + struct timer_list dsc_timer; + /* Read/Write dsc polling frequency */ + unsigned long best_dsc_rw_frequency; + /* The current polling frequency */ + unsigned long dsc_polling_frequency; + /* Maximum waiting time */ + unsigned long dsc_timeout; + + /* + * Read position information + */ + u8 partition; + /* Current block */ + unsigned int first_frame_position; + unsigned int last_frame_position; + unsigned int blocks_in_buffer; + + /* + * Last error information + */ + u8 sense_key, asc, ascq; + + /* + * Character device operation + */ + unsigned int minor; + /* device name */ + char name[4]; + /* Current character device data transfer direction */ + idetape_chrdev_direction_t chrdev_direction; + + /* + * Device information + */ + /* Usually 512 or 1024 bytes */ + unsigned short tape_block_size; + int user_bs_factor; + /* Copy of the tape's Capabilities and Mechanical Page */ + idetape_capabilities_page_t capabilities; + + /* + * Active data transfer request parameters. + * + * At most, there is only one ide-tape originated data transfer + * request in the device request queue. This allows ide.c to + * easily service requests from the other device when we + * postpone our active request. In the pipelined operation + * mode, we use our internal pipeline structure to hold + * more data requests. + * + * The data buffer size is chosen based on the tape's + * recommendation. + */ + /* Pointer to the request which is waiting in the device request queue */ + struct request *active_data_request; + /* Data buffer size (chosen based on the tape's recommendation */ + int stage_size; + idetape_stage_t *merge_stage; + int merge_stage_size; + struct idetape_bh *bh; + char *b_data; + int b_count; + + /* + * Pipeline parameters. + * + * To accomplish non-pipelined mode, we simply set the following + * variables to zero (or NULL, where appropriate). + */ + /* Number of currently used stages */ + int nr_stages; + /* Number of pending stages */ + int nr_pending_stages; + /* We will not allocate more than this number of stages */ + int max_stages, min_pipeline, max_pipeline; + /* The first stage which will be removed from the pipeline */ + idetape_stage_t *first_stage; + /* The currently active stage */ + idetape_stage_t *active_stage; + /* Will be serviced after the currently active request */ + idetape_stage_t *next_stage; + /* New requests will be added to the pipeline here */ + idetape_stage_t *last_stage; + /* Optional free stage which we can use */ + idetape_stage_t *cache_stage; + int pages_per_stage; + /* Wasted space in each stage */ + int excess_bh_size; + + /* Status/Action flags: long for set_bit */ + unsigned long flags; + /* protects the ide-tape queue */ + spinlock_t spinlock; + + /* + * Measures average tape speed + */ + unsigned long avg_time; + int avg_size; + int avg_speed; + + /* last sense information */ + idetape_request_sense_result_t sense; + + char vendor_id[10]; + char product_id[18]; + char firmware_revision[6]; + int firmware_revision_num; + + /* the door is currently locked */ + int door_locked; + /* the tape hardware is write protected */ + char drv_write_prot; + /* the tape is write protected (hardware or opened as read-only) */ + char write_prot; + + /* + * Limit the number of times a request can + * be postponed, to avoid an infinite postpone + * deadlock. + */ + /* request postpone count limit */ + int postpone_cnt; + + /* + * Measures number of frames: + * + * 1. written/read to/from the driver pipeline (pipeline_head). + * 2. written/read to/from the tape buffers (idetape_bh). + * 3. written/read by the tape to/from the media (tape_head). + */ + int pipeline_head; + int buffer_head; + int tape_head; + int last_tape_head; + + /* + * Speed control at the tape buffers input/output + */ + unsigned long insert_time; + int insert_size; + int insert_speed; + int max_insert_speed; + int measure_insert_time; + + /* + * Measure tape still time, in milliseconds + */ + unsigned long tape_still_time_begin; + int tape_still_time; + + /* + * Speed regulation negative feedback loop + */ + int speed_control; + int pipeline_head_speed; + int controlled_pipeline_head_speed; + int uncontrolled_pipeline_head_speed; + int controlled_last_pipeline_head; + int uncontrolled_last_pipeline_head; + unsigned long uncontrolled_pipeline_head_time; + unsigned long controlled_pipeline_head_time; + int controlled_previous_pipeline_head; + int uncontrolled_previous_pipeline_head; + unsigned long controlled_previous_head_time; + unsigned long uncontrolled_previous_head_time; + int restart_speed_control_req; + + /* + * Debug_level determines amount of debugging output; + * can be changed using /proc/ide/hdx/settings + * 0 : almost no debugging output + * 1 : 0+output errors only + * 2 : 1+output all sensekey/asc + * 3 : 2+follow all chrdev related procedures + * 4 : 3+follow all procedures + * 5 : 4+include pc_stack rq_stack info + * 6 : 5+USE_COUNT updates + */ + int debug_level; +} idetape_tape_t; + +static DECLARE_MUTEX(idetape_ref_sem); + +#define to_ide_tape(obj) container_of(obj, struct ide_tape_obj, kref) + +#define ide_tape_g(disk) \ + container_of((disk)->private_data, struct ide_tape_obj, driver) + +static struct ide_tape_obj *ide_tape_get(struct gendisk *disk) +{ + struct ide_tape_obj *tape = NULL; + + down(&idetape_ref_sem); + tape = ide_tape_g(disk); + if (tape) + kref_get(&tape->kref); + up(&idetape_ref_sem); + return tape; +} + +static void ide_tape_release(struct kref *); + +static void ide_tape_put(struct ide_tape_obj *tape) +{ + down(&idetape_ref_sem); + kref_put(&tape->kref, ide_tape_release); + up(&idetape_ref_sem); +} + +/* + * Tape door status + */ +#define DOOR_UNLOCKED 0 +#define DOOR_LOCKED 1 +#define DOOR_EXPLICITLY_LOCKED 2 + +/* + * Tape flag bits values. + */ +#define IDETAPE_IGNORE_DSC 0 +#define IDETAPE_ADDRESS_VALID 1 /* 0 When the tape position is unknown */ +#define IDETAPE_BUSY 2 /* Device already opened */ +#define IDETAPE_PIPELINE_ERROR 3 /* Error detected in a pipeline stage */ +#define IDETAPE_DETECT_BS 4 /* Attempt to auto-detect the current user block size */ +#define IDETAPE_FILEMARK 5 /* Currently on a filemark */ +#define IDETAPE_DRQ_INTERRUPT 6 /* DRQ interrupt device */ +#define IDETAPE_READ_ERROR 7 +#define IDETAPE_PIPELINE_ACTIVE 8 /* pipeline active */ +/* 0 = no tape is loaded, so we don't rewind after ejecting */ +#define IDETAPE_MEDIUM_PRESENT 9 + +/* + * Supported ATAPI tape drives packet commands + */ +#define IDETAPE_TEST_UNIT_READY_CMD 0x00 +#define IDETAPE_REWIND_CMD 0x01 +#define IDETAPE_REQUEST_SENSE_CMD 0x03 +#define IDETAPE_READ_CMD 0x08 +#define IDETAPE_WRITE_CMD 0x0a +#define IDETAPE_WRITE_FILEMARK_CMD 0x10 +#define IDETAPE_SPACE_CMD 0x11 +#define IDETAPE_INQUIRY_CMD 0x12 +#define IDETAPE_ERASE_CMD 0x19 +#define IDETAPE_MODE_SENSE_CMD 0x1a +#define IDETAPE_MODE_SELECT_CMD 0x15 +#define IDETAPE_LOAD_UNLOAD_CMD 0x1b +#define IDETAPE_PREVENT_CMD 0x1e +#define IDETAPE_LOCATE_CMD 0x2b +#define IDETAPE_READ_POSITION_CMD 0x34 +#define IDETAPE_READ_BUFFER_CMD 0x3c +#define IDETAPE_SET_SPEED_CMD 0xbb + +/* + * Some defines for the READ BUFFER command + */ +#define IDETAPE_RETRIEVE_FAULTY_BLOCK 6 + +/* + * Some defines for the SPACE command + */ +#define IDETAPE_SPACE_OVER_FILEMARK 1 +#define IDETAPE_SPACE_TO_EOD 3 + +/* + * Some defines for the LOAD UNLOAD command + */ +#define IDETAPE_LU_LOAD_MASK 1 +#define IDETAPE_LU_RETENSION_MASK 2 +#define IDETAPE_LU_EOT_MASK 4 + +/* + * Special requests for our block device strategy routine. + * + * In order to service a character device command, we add special + * requests to the tail of our block device request queue and wait + * for their completion. + */ + +enum { + REQ_IDETAPE_PC1 = (1 << 0), /* packet command (first stage) */ + REQ_IDETAPE_PC2 = (1 << 1), /* packet command (second stage) */ + REQ_IDETAPE_READ = (1 << 2), + REQ_IDETAPE_WRITE = (1 << 3), + REQ_IDETAPE_READ_BUFFER = (1 << 4), +}; + +/* + * Error codes which are returned in rq->errors to the higher part + * of the driver. + */ +#define IDETAPE_ERROR_GENERAL 101 +#define IDETAPE_ERROR_FILEMARK 102 +#define IDETAPE_ERROR_EOD 103 + +/* + * The following is used to format the general configuration word of + * the ATAPI IDENTIFY DEVICE command. + */ +struct idetape_id_gcw { + unsigned packet_size :2; /* Packet Size */ + unsigned reserved234 :3; /* Reserved */ + unsigned drq_type :2; /* Command packet DRQ type */ + unsigned removable :1; /* Removable media */ + unsigned device_type :5; /* Device type */ + unsigned reserved13 :1; /* Reserved */ + unsigned protocol :2; /* Protocol type */ +}; + +/* + * INQUIRY packet command - Data Format (From Table 6-8 of QIC-157C) + */ +typedef struct { + unsigned device_type :5; /* Peripheral Device Type */ + unsigned reserved0_765 :3; /* Peripheral Qualifier - Reserved */ + unsigned reserved1_6t0 :7; /* Reserved */ + unsigned rmb :1; /* Removable Medium Bit */ + unsigned ansi_version :3; /* ANSI Version */ + unsigned ecma_version :3; /* ECMA Version */ + unsigned iso_version :2; /* ISO Version */ + unsigned response_format :4; /* Response Data Format */ + unsigned reserved3_45 :2; /* Reserved */ + unsigned reserved3_6 :1; /* TrmIOP - Reserved */ + unsigned reserved3_7 :1; /* AENC - Reserved */ + __u8 additional_length; /* Additional Length (total_length-4) */ + __u8 rsv5, rsv6, rsv7; /* Reserved */ + __u8 vendor_id[8]; /* Vendor Identification */ + __u8 product_id[16]; /* Product Identification */ + __u8 revision_level[4]; /* Revision Level */ + __u8 vendor_specific[20]; /* Vendor Specific - Optional */ + __u8 reserved56t95[40]; /* Reserved - Optional */ + /* Additional information may be returned */ +} idetape_inquiry_result_t; + +/* + * READ POSITION packet command - Data Format (From Table 6-57) + */ +typedef struct { + unsigned reserved0_10 :2; /* Reserved */ + unsigned bpu :1; /* Block Position Unknown */ + unsigned reserved0_543 :3; /* Reserved */ + unsigned eop :1; /* End Of Partition */ + unsigned bop :1; /* Beginning Of Partition */ + u8 partition; /* Partition Number */ + u8 reserved2, reserved3; /* Reserved */ + u32 first_block; /* First Block Location */ + u32 last_block; /* Last Block Location (Optional) */ + u8 reserved12; /* Reserved */ + u8 blocks_in_buffer[3]; /* Blocks In Buffer - (Optional) */ + u32 bytes_in_buffer; /* Bytes In Buffer (Optional) */ +} idetape_read_position_result_t; + +/* + * Follows structures which are related to the SELECT SENSE / MODE SENSE + * packet commands. Those packet commands are still not supported + * by ide-tape. + */ +#define IDETAPE_BLOCK_DESCRIPTOR 0 +#define IDETAPE_CAPABILITIES_PAGE 0x2a +#define IDETAPE_PARAMTR_PAGE 0x2b /* Onstream DI-x0 only */ +#define IDETAPE_BLOCK_SIZE_PAGE 0x30 +#define IDETAPE_BUFFER_FILLING_PAGE 0x33 + +/* + * Mode Parameter Header for the MODE SENSE packet command + */ +typedef struct { + __u8 mode_data_length; /* Length of the following data transfer */ + __u8 medium_type; /* Medium Type */ + __u8 dsp; /* Device Specific Parameter */ + __u8 bdl; /* Block Descriptor Length */ +#if 0 + /* data transfer page */ + __u8 page_code :6; + __u8 reserved0_6 :1; + __u8 ps :1; /* parameters saveable */ + __u8 page_length; /* page Length == 0x02 */ + __u8 reserved2; + __u8 read32k :1; /* 32k blk size (data only) */ + __u8 read32k5 :1; /* 32.5k blk size (data&AUX) */ + __u8 reserved3_23 :2; + __u8 write32k :1; /* 32k blk size (data only) */ + __u8 write32k5 :1; /* 32.5k blk size (data&AUX) */ + __u8 reserved3_6 :1; + __u8 streaming :1; /* streaming mode enable */ +#endif +} idetape_mode_parameter_header_t; + +/* + * Mode Parameter Block Descriptor the MODE SENSE packet command + * + * Support for block descriptors is optional. + */ +typedef struct { + __u8 density_code; /* Medium density code */ + __u8 blocks[3]; /* Number of blocks */ + __u8 reserved4; /* Reserved */ + __u8 length[3]; /* Block Length */ +} idetape_parameter_block_descriptor_t; + +/* + * The Data Compression Page, as returned by the MODE SENSE packet command. + */ +typedef struct { + unsigned page_code :6; /* Page Code - Should be 0xf */ + unsigned reserved0 :1; /* Reserved */ + unsigned ps :1; + __u8 page_length; /* Page Length - Should be 14 */ + unsigned reserved2 :6; /* Reserved */ + unsigned dcc :1; /* Data Compression Capable */ + unsigned dce :1; /* Data Compression Enable */ + unsigned reserved3 :5; /* Reserved */ + unsigned red :2; /* Report Exception on Decompression */ + unsigned dde :1; /* Data Decompression Enable */ + __u32 ca; /* Compression Algorithm */ + __u32 da; /* Decompression Algorithm */ + __u8 reserved[4]; /* Reserved */ +} idetape_data_compression_page_t; + +/* + * The Medium Partition Page, as returned by the MODE SENSE packet command. + */ +typedef struct { + unsigned page_code :6; /* Page Code - Should be 0x11 */ + unsigned reserved1_6 :1; /* Reserved */ + unsigned ps :1; + __u8 page_length; /* Page Length - Should be 6 */ + __u8 map; /* Maximum Additional Partitions - Should be 0 */ + __u8 apd; /* Additional Partitions Defined - Should be 0 */ + unsigned reserved4_012 :3; /* Reserved */ + unsigned psum :2; /* Should be 0 */ + unsigned idp :1; /* Should be 0 */ + unsigned sdp :1; /* Should be 0 */ + unsigned fdp :1; /* Fixed Data Partitions */ + __u8 mfr; /* Medium Format Recognition */ + __u8 reserved[2]; /* Reserved */ +} idetape_medium_partition_page_t; + +/* + * Run time configurable parameters. + */ +typedef struct { + int dsc_rw_frequency; + int dsc_media_access_frequency; + int nr_stages; +} idetape_config_t; + +/* + * The variables below are used for the character device interface. + * Additional state variables are defined in our ide_drive_t structure. + */ +static struct ide_tape_obj * idetape_devs[MAX_HWIFS * MAX_DRIVES]; + +#define ide_tape_f(file) ((file)->private_data) + +static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i) +{ + struct ide_tape_obj *tape = NULL; + + down(&idetape_ref_sem); + tape = idetape_devs[i]; + if (tape) + kref_get(&tape->kref); + up(&idetape_ref_sem); + return tape; +} + +/* + * Function declarations + * + */ +static int idetape_chrdev_release (struct inode *inode, struct file *filp); +static void idetape_write_release (ide_drive_t *drive, unsigned int minor); + +/* + * Too bad. The drive wants to send us data which we are not ready to accept. + * Just throw it away. + */ +static void idetape_discard_data (ide_drive_t *drive, unsigned int bcount) +{ + while (bcount--) + (void) HWIF(drive)->INB(IDE_DATA_REG); +} + +static void idetape_input_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount) +{ + struct idetape_bh *bh = pc->bh; + int count; + + while (bcount) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk(KERN_ERR "ide-tape: bh == NULL in " + "idetape_input_buffers\n"); + idetape_discard_data(drive, bcount); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), bcount); + HWIF(drive)->atapi_input_bytes(drive, bh->b_data + atomic_read(&bh->b_count), count); + bcount -= count; + atomic_add(count, &bh->b_count); + if (atomic_read(&bh->b_count) == bh->b_size) { + bh = bh->b_reqnext; + if (bh) + atomic_set(&bh->b_count, 0); + } + } + pc->bh = bh; +} + +static void idetape_output_buffers (ide_drive_t *drive, idetape_pc_t *pc, unsigned int bcount) +{ + struct idetape_bh *bh = pc->bh; + int count; + + while (bcount) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk(KERN_ERR "ide-tape: bh == NULL in " + "idetape_output_buffers\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = min((unsigned int)pc->b_count, (unsigned int)bcount); + HWIF(drive)->atapi_output_bytes(drive, pc->b_data, count); + bcount -= count; + pc->b_data += count; + pc->b_count -= count; + if (!pc->b_count) { + pc->bh = bh = bh->b_reqnext; + if (bh) { + pc->b_data = bh->b_data; + pc->b_count = atomic_read(&bh->b_count); + } + } + } +} + +static void idetape_update_buffers (idetape_pc_t *pc) +{ + struct idetape_bh *bh = pc->bh; + int count; + unsigned int bcount = pc->actually_transferred; + + if (test_bit(PC_WRITING, &pc->flags)) + return; + while (bcount) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk(KERN_ERR "ide-tape: bh == NULL in " + "idetape_update_buffers\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = min((unsigned int)bh->b_size, (unsigned int)bcount); + atomic_set(&bh->b_count, count); + if (atomic_read(&bh->b_count) == bh->b_size) + bh = bh->b_reqnext; + bcount -= count; + } + pc->bh = bh; +} + +/* + * idetape_next_pc_storage returns a pointer to a place in which we can + * safely store a packet command, even though we intend to leave the + * driver. A storage space for a maximum of IDETAPE_PC_STACK packet + * commands is allocated at initialization time. + */ +static idetape_pc_t *idetape_next_pc_storage (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 5) + printk(KERN_INFO "ide-tape: pc_stack_index=%d\n", + tape->pc_stack_index); +#endif /* IDETAPE_DEBUG_LOG */ + if (tape->pc_stack_index == IDETAPE_PC_STACK) + tape->pc_stack_index=0; + return (&tape->pc_stack[tape->pc_stack_index++]); +} + +/* + * idetape_next_rq_storage is used along with idetape_next_pc_storage. + * Since we queue packet commands in the request queue, we need to + * allocate a request, along with the allocation of a packet command. + */ + +/************************************************************** + * * + * This should get fixed to use kmalloc(.., GFP_ATOMIC) * + * followed later on by kfree(). -ml * + * * + **************************************************************/ + +static struct request *idetape_next_rq_storage (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 5) + printk(KERN_INFO "ide-tape: rq_stack_index=%d\n", + tape->rq_stack_index); +#endif /* IDETAPE_DEBUG_LOG */ + if (tape->rq_stack_index == IDETAPE_PC_STACK) + tape->rq_stack_index=0; + return (&tape->rq_stack[tape->rq_stack_index++]); +} + +/* + * idetape_init_pc initializes a packet command. + */ +static void idetape_init_pc (idetape_pc_t *pc) +{ + memset(pc->c, 0, 12); + pc->retries = 0; + pc->flags = 0; + pc->request_transfer = 0; + pc->buffer = pc->pc_buffer; + pc->buffer_size = IDETAPE_PC_BUFFER_SIZE; + pc->bh = NULL; + pc->b_data = NULL; +} + +/* + * idetape_analyze_error is called on each failed packet command retry + * to analyze the request sense. We currently do not utilize this + * information. + */ +static void idetape_analyze_error (ide_drive_t *drive, idetape_request_sense_result_t *result) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc = tape->failed_pc; + + tape->sense = *result; + tape->sense_key = result->sense_key; + tape->asc = result->asc; + tape->ascq = result->ascq; +#if IDETAPE_DEBUG_LOG + /* + * Without debugging, we only log an error if we decided to + * give up retrying. + */ + if (tape->debug_level >= 1) + printk(KERN_INFO "ide-tape: pc = %x, sense key = %x, " + "asc = %x, ascq = %x\n", + pc->c[0], result->sense_key, + result->asc, result->ascq); +#endif /* IDETAPE_DEBUG_LOG */ + + /* + * Correct pc->actually_transferred by asking the tape. + */ + if (test_bit(PC_DMA_ERROR, &pc->flags)) { + pc->actually_transferred = pc->request_transfer - tape->tape_block_size * ntohl(get_unaligned(&result->information)); + idetape_update_buffers(pc); + } + + /* + * If error was the result of a zero-length read or write command, + * with sense key=5, asc=0x22, ascq=0, let it slide. Some drives + * (i.e. Seagate STT3401A Travan) don't support 0-length read/writes. + */ + if ((pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) + && pc->c[4] == 0 && pc->c[3] == 0 && pc->c[2] == 0) { /* length==0 */ + if (result->sense_key == 5) { + /* don't report an error, everything's ok */ + pc->error = 0; + /* don't retry read/write */ + set_bit(PC_ABORT, &pc->flags); + } + } + if (pc->c[0] == IDETAPE_READ_CMD && result->filemark) { + pc->error = IDETAPE_ERROR_FILEMARK; + set_bit(PC_ABORT, &pc->flags); + } + if (pc->c[0] == IDETAPE_WRITE_CMD) { + if (result->eom || + (result->sense_key == 0xd && result->asc == 0x0 && + result->ascq == 0x2)) { + pc->error = IDETAPE_ERROR_EOD; + set_bit(PC_ABORT, &pc->flags); + } + } + if (pc->c[0] == IDETAPE_READ_CMD || pc->c[0] == IDETAPE_WRITE_CMD) { + if (result->sense_key == 8) { + pc->error = IDETAPE_ERROR_EOD; + set_bit(PC_ABORT, &pc->flags); + } + if (!test_bit(PC_ABORT, &pc->flags) && + pc->actually_transferred) + pc->retries = IDETAPE_MAX_PC_RETRIES + 1; + } +} + +/* + * idetape_active_next_stage will declare the next stage as "active". + */ +static void idetape_active_next_stage (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage = tape->next_stage; + struct request *rq = &stage->rq; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_active_next_stage\n"); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (stage == NULL) { + printk(KERN_ERR "ide-tape: bug: Trying to activate a non existing stage\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + + rq->rq_disk = tape->disk; + rq->buffer = NULL; + rq->special = (void *)stage->bh; + tape->active_data_request = rq; + tape->active_stage = stage; + tape->next_stage = stage->next; +} + +/* + * idetape_increase_max_pipeline_stages is a part of the feedback + * loop which tries to find the optimum number of stages. In the + * feedback loop, we are starting from a minimum maximum number of + * stages, and if we sense that the pipeline is empty, we try to + * increase it, until we reach the user compile time memory limit. + */ +static void idetape_increase_max_pipeline_stages (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + int increase = (tape->max_pipeline - tape->min_pipeline) / 10; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk (KERN_INFO "ide-tape: Reached idetape_increase_max_pipeline_stages\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + tape->max_stages += max(increase, 1); + tape->max_stages = max(tape->max_stages, tape->min_pipeline); + tape->max_stages = min(tape->max_stages, tape->max_pipeline); +} + +/* + * idetape_kfree_stage calls kfree to completely free a stage, along with + * its related buffers. + */ +static void __idetape_kfree_stage (idetape_stage_t *stage) +{ + struct idetape_bh *prev_bh, *bh = stage->bh; + int size; + + while (bh != NULL) { + if (bh->b_data != NULL) { + size = (int) bh->b_size; + while (size > 0) { + free_page((unsigned long) bh->b_data); + size -= PAGE_SIZE; + bh->b_data += PAGE_SIZE; + } + } + prev_bh = bh; + bh = bh->b_reqnext; + kfree(prev_bh); + } + kfree(stage); +} + +static void idetape_kfree_stage (idetape_tape_t *tape, idetape_stage_t *stage) +{ + __idetape_kfree_stage(stage); +} + +/* + * idetape_remove_stage_head removes tape->first_stage from the pipeline. + * The caller should avoid race conditions. + */ +static void idetape_remove_stage_head (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_remove_stage_head\n"); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (tape->first_stage == NULL) { + printk(KERN_ERR "ide-tape: bug: tape->first_stage is NULL\n"); + return; + } + if (tape->active_stage == tape->first_stage) { + printk(KERN_ERR "ide-tape: bug: Trying to free our active pipeline stage\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + stage = tape->first_stage; + tape->first_stage = stage->next; + idetape_kfree_stage(tape, stage); + tape->nr_stages--; + if (tape->first_stage == NULL) { + tape->last_stage = NULL; +#if IDETAPE_DEBUG_BUGS + if (tape->next_stage != NULL) + printk(KERN_ERR "ide-tape: bug: tape->next_stage != NULL\n"); + if (tape->nr_stages) + printk(KERN_ERR "ide-tape: bug: nr_stages should be 0 now\n"); +#endif /* IDETAPE_DEBUG_BUGS */ + } +} + +/* + * This will free all the pipeline stages starting from new_last_stage->next + * to the end of the list, and point tape->last_stage to new_last_stage. + */ +static void idetape_abort_pipeline(ide_drive_t *drive, + idetape_stage_t *new_last_stage) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage = new_last_stage->next; + idetape_stage_t *nstage; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: %s: idetape_abort_pipeline called\n", tape->name); +#endif + while (stage) { + nstage = stage->next; + idetape_kfree_stage(tape, stage); + --tape->nr_stages; + --tape->nr_pending_stages; + stage = nstage; + } + if (new_last_stage) + new_last_stage->next = NULL; + tape->last_stage = new_last_stage; + tape->next_stage = NULL; +} + +/* + * idetape_end_request is used to finish servicing a request, and to + * insert a pending pipeline request into the main device queue. + */ +static int idetape_end_request(ide_drive_t *drive, int uptodate, int nr_sects) +{ + struct request *rq = HWGROUP(drive)->rq; + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + int error; + int remove_stage = 0; + idetape_stage_t *active_stage; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_end_request\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + switch (uptodate) { + case 0: error = IDETAPE_ERROR_GENERAL; break; + case 1: error = 0; break; + default: error = uptodate; + } + rq->errors = error; + if (error) + tape->failed_pc = NULL; + + spin_lock_irqsave(&tape->spinlock, flags); + + /* The request was a pipelined data transfer request */ + if (tape->active_data_request == rq) { + active_stage = tape->active_stage; + tape->active_stage = NULL; + tape->active_data_request = NULL; + tape->nr_pending_stages--; + if (rq->cmd[0] & REQ_IDETAPE_WRITE) { + remove_stage = 1; + if (error) { + set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); + if (error == IDETAPE_ERROR_EOD) + idetape_abort_pipeline(drive, active_stage); + } + } else if (rq->cmd[0] & REQ_IDETAPE_READ) { + if (error == IDETAPE_ERROR_EOD) { + set_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); + idetape_abort_pipeline(drive, active_stage); + } + } + if (tape->next_stage != NULL) { + idetape_active_next_stage(drive); + + /* + * Insert the next request into the request queue. + */ + (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end); + } else if (!error) { + idetape_increase_max_pipeline_stages(drive); + } + } + ide_end_drive_cmd(drive, 0, 0); +// blkdev_dequeue_request(rq); +// drive->rq = NULL; +// end_that_request_last(rq); + + if (remove_stage) + idetape_remove_stage_head(drive); + if (tape->active_data_request == NULL) + clear_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags); + spin_unlock_irqrestore(&tape->spinlock, flags); + return 0; +} + +static ide_startstop_t idetape_request_sense_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_request_sense_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + if (!tape->pc->error) { + idetape_analyze_error(drive, (idetape_request_sense_result_t *) tape->pc->buffer); + idetape_end_request(drive, 1, 0); + } else { + printk(KERN_ERR "ide-tape: Error in REQUEST SENSE itself - Aborting request!\n"); + idetape_end_request(drive, 0, 0); + } + return ide_stopped; +} + +static void idetape_create_request_sense_cmd (idetape_pc_t *pc) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_REQUEST_SENSE_CMD; + pc->c[4] = 20; + pc->request_transfer = 20; + pc->callback = &idetape_request_sense_callback; +} + +static void idetape_init_rq(struct request *rq, u8 cmd) +{ + memset(rq, 0, sizeof(*rq)); + rq->flags = REQ_SPECIAL; + rq->cmd[0] = cmd; +} + +/* + * idetape_queue_pc_head generates a new packet command request in front + * of the request queue, before the current request, so that it will be + * processed immediately, on the next pass through the driver. + * + * idetape_queue_pc_head is called from the request handling part of + * the driver (the "bottom" part). Safe storage for the request should + * be allocated with idetape_next_pc_storage and idetape_next_rq_storage + * before calling idetape_queue_pc_head. + * + * Memory for those requests is pre-allocated at initialization time, and + * is limited to IDETAPE_PC_STACK requests. We assume that we have enough + * space for the maximum possible number of inter-dependent packet commands. + * + * The higher level of the driver - The ioctl handler and the character + * device handling functions should queue request to the lower level part + * and wait for their completion using idetape_queue_pc_tail or + * idetape_queue_rw_tail. + */ +static void idetape_queue_pc_head (ide_drive_t *drive, idetape_pc_t *pc,struct request *rq) +{ + struct ide_tape_obj *tape = drive->driver_data; + + idetape_init_rq(rq, REQ_IDETAPE_PC1); + rq->buffer = (char *) pc; + rq->rq_disk = tape->disk; + (void) ide_do_drive_cmd(drive, rq, ide_preempt); +} + +/* + * idetape_retry_pc is called when an error was detected during the + * last packet command. We queue a request sense packet command in + * the head of the request list. + */ +static ide_startstop_t idetape_retry_pc (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc; + struct request *rq; + atapi_error_t error; + + error.all = HWIF(drive)->INB(IDE_ERROR_REG); + pc = idetape_next_pc_storage(drive); + rq = idetape_next_rq_storage(drive); + idetape_create_request_sense_cmd(pc); + set_bit(IDETAPE_IGNORE_DSC, &tape->flags); + idetape_queue_pc_head(drive, pc, rq); + return ide_stopped; +} + +/* + * idetape_postpone_request postpones the current request so that + * ide.c will be able to service requests from another device on + * the same hwgroup while we are polling for DSC. + */ +static void idetape_postpone_request (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: idetape_postpone_request\n"); +#endif + tape->postponed_rq = HWGROUP(drive)->rq; + ide_stall_queue(drive, tape->dsc_polling_frequency); +} + +/* + * idetape_pc_intr is the usual interrupt handler which will be called + * during a packet command. We will transfer some of the data (as + * requested by the drive) and will re-point interrupt handler to us. + * When data transfer is finished, we will act according to the + * algorithm described before idetape_issue_packet_command. + * + */ +static ide_startstop_t idetape_pc_intr (ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + idetape_tape_t *tape = drive->driver_data; + atapi_status_t status; + atapi_bcount_t bcount; + atapi_ireason_t ireason; + idetape_pc_t *pc = tape->pc; + + unsigned int temp; +#if SIMULATE_ERRORS + static int error_sim_count = 0; +#endif + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_pc_intr " + "interrupt handler\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + /* Clear the interrupt */ + status.all = HWIF(drive)->INB(IDE_STATUS_REG); + + if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) { + if (HWIF(drive)->ide_dma_end(drive) || status.b.check) { + /* + * A DMA error is sometimes expected. For example, + * if the tape is crossing a filemark during a + * READ command, it will issue an irq and position + * itself before the filemark, so that only a partial + * data transfer will occur (which causes the DMA + * error). In that case, we will later ask the tape + * how much bytes of the original request were + * actually transferred (we can't receive that + * information from the DMA engine on most chipsets). + */ + + /* + * On the contrary, a DMA error is never expected; + * it usually indicates a hardware error or abort. + * If the tape crosses a filemark during a READ + * command, it will issue an irq and position itself + * after the filemark (not before). Only a partial + * data transfer will occur, but no DMA error. + * (AS, 19 Apr 2001) + */ + set_bit(PC_DMA_ERROR, &pc->flags); + } else { + pc->actually_transferred = pc->request_transfer; + idetape_update_buffers(pc); + } +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: DMA finished\n"); +#endif /* IDETAPE_DEBUG_LOG */ + } + + /* No more interrupts */ + if (!status.b.drq) { +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: Packet command completed, %d bytes transferred\n", pc->actually_transferred); +#endif /* IDETAPE_DEBUG_LOG */ + clear_bit(PC_DMA_IN_PROGRESS, &pc->flags); + + local_irq_enable(); + +#if SIMULATE_ERRORS + if ((pc->c[0] == IDETAPE_WRITE_CMD || + pc->c[0] == IDETAPE_READ_CMD) && + (++error_sim_count % 100) == 0) { + printk(KERN_INFO "ide-tape: %s: simulating error\n", + tape->name); + status.b.check = 1; + } +#endif + if (status.b.check && pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) + status.b.check = 0; + if (status.b.check || test_bit(PC_DMA_ERROR, &pc->flags)) { /* Error detected */ +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 1) + printk(KERN_INFO "ide-tape: %s: I/O error\n", + tape->name); +#endif /* IDETAPE_DEBUG_LOG */ + if (pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) { + printk(KERN_ERR "ide-tape: I/O error in request sense command\n"); + return ide_do_reset(drive); + } +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 1) + printk(KERN_INFO "ide-tape: [cmd %x]: check condition\n", pc->c[0]); +#endif + /* Retry operation */ + return idetape_retry_pc(drive); + } + pc->error = 0; + if (test_bit(PC_WAIT_FOR_DSC, &pc->flags) && + !status.b.dsc) { + /* Media access command */ + tape->dsc_polling_start = jiffies; + tape->dsc_polling_frequency = IDETAPE_DSC_MA_FAST; + tape->dsc_timeout = jiffies + IDETAPE_DSC_MA_TIMEOUT; + /* Allow ide.c to handle other requests */ + idetape_postpone_request(drive); + return ide_stopped; + } + if (tape->failed_pc == pc) + tape->failed_pc = NULL; + /* Command finished - Call the callback function */ + return pc->callback(drive); + } + if (test_and_clear_bit(PC_DMA_IN_PROGRESS, &pc->flags)) { + printk(KERN_ERR "ide-tape: The tape wants to issue more " + "interrupts in DMA mode\n"); + printk(KERN_ERR "ide-tape: DMA disabled, reverting to PIO\n"); + (void)__ide_dma_off(drive); + return ide_do_reset(drive); + } + /* Get the number of bytes to transfer on this interrupt. */ + bcount.b.high = hwif->INB(IDE_BCOUNTH_REG); + bcount.b.low = hwif->INB(IDE_BCOUNTL_REG); + + ireason.all = hwif->INB(IDE_IREASON_REG); + + if (ireason.b.cod) { + printk(KERN_ERR "ide-tape: CoD != 0 in idetape_pc_intr\n"); + return ide_do_reset(drive); + } + if (ireason.b.io == test_bit(PC_WRITING, &pc->flags)) { + /* Hopefully, we will never get here */ + printk(KERN_ERR "ide-tape: We wanted to %s, ", + ireason.b.io ? "Write":"Read"); + printk(KERN_ERR "ide-tape: but the tape wants us to %s !\n", + ireason.b.io ? "Read":"Write"); + return ide_do_reset(drive); + } + if (!test_bit(PC_WRITING, &pc->flags)) { + /* Reading - Check that we have enough space */ + temp = pc->actually_transferred + bcount.all; + if (temp > pc->request_transfer) { + if (temp > pc->buffer_size) { + printk(KERN_ERR "ide-tape: The tape wants to send us more data than expected - discarding data\n"); + idetape_discard_data(drive, bcount.all); + ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); + return ide_started; + } +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_NOTICE "ide-tape: The tape wants to send us more data than expected - allowing transfer\n"); +#endif /* IDETAPE_DEBUG_LOG */ + } + } + if (test_bit(PC_WRITING, &pc->flags)) { + if (pc->bh != NULL) + idetape_output_buffers(drive, pc, bcount.all); + else + /* Write the current buffer */ + HWIF(drive)->atapi_output_bytes(drive, pc->current_position, bcount.all); + } else { + if (pc->bh != NULL) + idetape_input_buffers(drive, pc, bcount.all); + else + /* Read the current buffer */ + HWIF(drive)->atapi_input_bytes(drive, pc->current_position, bcount.all); + } + /* Update the current position */ + pc->actually_transferred += bcount.all; + pc->current_position += bcount.all; +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: [cmd %x] transferred %d bytes on that interrupt\n", pc->c[0], bcount.all); +#endif + /* And set the interrupt handler again */ + ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); + return ide_started; +} + +/* + * Packet Command Interface + * + * The current Packet Command is available in tape->pc, and will not + * change until we finish handling it. Each packet command is associated + * with a callback function that will be called when the command is + * finished. + * + * The handling will be done in three stages: + * + * 1. idetape_issue_packet_command will send the packet command to the + * drive, and will set the interrupt handler to idetape_pc_intr. + * + * 2. On each interrupt, idetape_pc_intr will be called. This step + * will be repeated until the device signals us that no more + * interrupts will be issued. + * + * 3. ATAPI Tape media access commands have immediate status with a + * delayed process. In case of a successful initiation of a + * media access packet command, the DSC bit will be set when the + * actual execution of the command is finished. + * Since the tape drive will not issue an interrupt, we have to + * poll for this event. In this case, we define the request as + * "low priority request" by setting rq_status to + * IDETAPE_RQ_POSTPONED, set a timer to poll for DSC and exit + * the driver. + * + * ide.c will then give higher priority to requests which + * originate from the other device, until will change rq_status + * to RQ_ACTIVE. + * + * 4. When the packet command is finished, it will be checked for errors. + * + * 5. In case an error was found, we queue a request sense packet + * command in front of the request queue and retry the operation + * up to IDETAPE_MAX_PC_RETRIES times. + * + * 6. In case no error was found, or we decided to give up and not + * to retry again, the callback function will be called and then + * we will handle the next request. + * + */ +static ide_startstop_t idetape_transfer_pc(ide_drive_t *drive) +{ + ide_hwif_t *hwif = drive->hwif; + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc = tape->pc; + atapi_ireason_t ireason; + int retries = 100; + ide_startstop_t startstop; + + if (ide_wait_stat(&startstop,drive,DRQ_STAT,BUSY_STAT,WAIT_READY)) { + printk(KERN_ERR "ide-tape: Strange, packet command initiated yet DRQ isn't asserted\n"); + return startstop; + } + ireason.all = hwif->INB(IDE_IREASON_REG); + while (retries-- && (!ireason.b.cod || ireason.b.io)) { + printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while issuing " + "a packet command, retrying\n"); + udelay(100); + ireason.all = hwif->INB(IDE_IREASON_REG); + if (retries == 0) { + printk(KERN_ERR "ide-tape: (IO,CoD != (0,1) while " + "issuing a packet command, ignoring\n"); + ireason.b.cod = 1; + ireason.b.io = 0; + } + } + if (!ireason.b.cod || ireason.b.io) { + printk(KERN_ERR "ide-tape: (IO,CoD) != (0,1) while issuing " + "a packet command\n"); + return ide_do_reset(drive); + } + /* Set the interrupt routine */ + ide_set_handler(drive, &idetape_pc_intr, IDETAPE_WAIT_CMD, NULL); +#ifdef CONFIG_BLK_DEV_IDEDMA + /* Begin DMA, if necessary */ + if (test_bit(PC_DMA_IN_PROGRESS, &pc->flags)) + hwif->dma_start(drive); +#endif + /* Send the actual packet */ + HWIF(drive)->atapi_output_bytes(drive, pc->c, 12); + return ide_started; +} + +static ide_startstop_t idetape_issue_packet_command (ide_drive_t *drive, idetape_pc_t *pc) +{ + ide_hwif_t *hwif = drive->hwif; + idetape_tape_t *tape = drive->driver_data; + atapi_bcount_t bcount; + int dma_ok = 0; + +#if IDETAPE_DEBUG_BUGS + if (tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD && + pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) { + printk(KERN_ERR "ide-tape: possible ide-tape.c bug - " + "Two request sense in serial were issued\n"); + } +#endif /* IDETAPE_DEBUG_BUGS */ + + if (tape->failed_pc == NULL && pc->c[0] != IDETAPE_REQUEST_SENSE_CMD) + tape->failed_pc = pc; + /* Set the current packet command */ + tape->pc = pc; + + if (pc->retries > IDETAPE_MAX_PC_RETRIES || + test_bit(PC_ABORT, &pc->flags)) { + /* + * We will "abort" retrying a packet command in case + * a legitimate error code was received (crossing a + * filemark, or end of the media, for example). + */ + if (!test_bit(PC_ABORT, &pc->flags)) { + if (!(pc->c[0] == IDETAPE_TEST_UNIT_READY_CMD && + tape->sense_key == 2 && tape->asc == 4 && + (tape->ascq == 1 || tape->ascq == 8))) { + printk(KERN_ERR "ide-tape: %s: I/O error, " + "pc = %2x, key = %2x, " + "asc = %2x, ascq = %2x\n", + tape->name, pc->c[0], + tape->sense_key, tape->asc, + tape->ascq); + } + /* Giving up */ + pc->error = IDETAPE_ERROR_GENERAL; + } + tape->failed_pc = NULL; + return pc->callback(drive); + } +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: Retry number - %d, cmd = %02X\n", pc->retries, pc->c[0]); +#endif /* IDETAPE_DEBUG_LOG */ + + pc->retries++; + /* We haven't transferred any data yet */ + pc->actually_transferred = 0; + pc->current_position = pc->buffer; + /* Request to transfer the entire buffer at once */ + bcount.all = pc->request_transfer; + + if (test_and_clear_bit(PC_DMA_ERROR, &pc->flags)) { + printk(KERN_WARNING "ide-tape: DMA disabled, " + "reverting to PIO\n"); + (void)__ide_dma_off(drive); + } + if (test_bit(PC_DMA_RECOMMENDED, &pc->flags) && drive->using_dma) + dma_ok = !hwif->dma_setup(drive); + + if (IDE_CONTROL_REG) + hwif->OUTB(drive->ctl, IDE_CONTROL_REG); + hwif->OUTB(dma_ok ? 1 : 0, IDE_FEATURE_REG); /* Use PIO/DMA */ + hwif->OUTB(bcount.b.high, IDE_BCOUNTH_REG); + hwif->OUTB(bcount.b.low, IDE_BCOUNTL_REG); + hwif->OUTB(drive->select.all, IDE_SELECT_REG); + if (dma_ok) /* Will begin DMA later */ + set_bit(PC_DMA_IN_PROGRESS, &pc->flags); + if (test_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags)) { + ide_set_handler(drive, &idetape_transfer_pc, IDETAPE_WAIT_CMD, NULL); + hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG); + return ide_started; + } else { + hwif->OUTB(WIN_PACKETCMD, IDE_COMMAND_REG); + return idetape_transfer_pc(drive); + } +} + +/* + * General packet command callback function. + */ +static ide_startstop_t idetape_pc_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_pc_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + idetape_end_request(drive, tape->pc->error ? 0 : 1, 0); + return ide_stopped; +} + +/* + * A mode sense command is used to "sense" tape parameters. + */ +static void idetape_create_mode_sense_cmd (idetape_pc_t *pc, u8 page_code) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_MODE_SENSE_CMD; + if (page_code != IDETAPE_BLOCK_DESCRIPTOR) + pc->c[1] = 8; /* DBD = 1 - Don't return block descriptors */ + pc->c[2] = page_code; + /* + * Changed pc->c[3] to 0 (255 will at best return unused info). + * + * For SCSI this byte is defined as subpage instead of high byte + * of length and some IDE drives seem to interpret it this way + * and return an error when 255 is used. + */ + pc->c[3] = 0; + pc->c[4] = 255; /* (We will just discard data in that case) */ + if (page_code == IDETAPE_BLOCK_DESCRIPTOR) + pc->request_transfer = 12; + else if (page_code == IDETAPE_CAPABILITIES_PAGE) + pc->request_transfer = 24; + else + pc->request_transfer = 50; + pc->callback = &idetape_pc_callback; +} + +static void calculate_speeds(ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + int full = 125, empty = 75; + + if (time_after(jiffies, tape->controlled_pipeline_head_time + 120 * HZ)) { + tape->controlled_previous_pipeline_head = tape->controlled_last_pipeline_head; + tape->controlled_previous_head_time = tape->controlled_pipeline_head_time; + tape->controlled_last_pipeline_head = tape->pipeline_head; + tape->controlled_pipeline_head_time = jiffies; + } + if (time_after(jiffies, tape->controlled_pipeline_head_time + 60 * HZ)) + tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_last_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_pipeline_head_time); + else if (time_after(jiffies, tape->controlled_previous_head_time)) + tape->controlled_pipeline_head_speed = (tape->pipeline_head - tape->controlled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->controlled_previous_head_time); + + if (tape->nr_pending_stages < tape->max_stages /*- 1 */) { + /* -1 for read mode error recovery */ + if (time_after(jiffies, tape->uncontrolled_previous_head_time + 10 * HZ)) { + tape->uncontrolled_pipeline_head_time = jiffies; + tape->uncontrolled_pipeline_head_speed = (tape->pipeline_head - tape->uncontrolled_previous_pipeline_head) * 32 * HZ / (jiffies - tape->uncontrolled_previous_head_time); + } + } else { + tape->uncontrolled_previous_head_time = jiffies; + tape->uncontrolled_previous_pipeline_head = tape->pipeline_head; + if (time_after(jiffies, tape->uncontrolled_pipeline_head_time + 30 * HZ)) { + tape->uncontrolled_pipeline_head_time = jiffies; + } + } + tape->pipeline_head_speed = max(tape->uncontrolled_pipeline_head_speed, tape->controlled_pipeline_head_speed); + if (tape->speed_control == 0) { + tape->max_insert_speed = 5000; + } else if (tape->speed_control == 1) { + if (tape->nr_pending_stages >= tape->max_stages / 2) + tape->max_insert_speed = tape->pipeline_head_speed + + (1100 - tape->pipeline_head_speed) * 2 * (tape->nr_pending_stages - tape->max_stages / 2) / tape->max_stages; + else + tape->max_insert_speed = 500 + + (tape->pipeline_head_speed - 500) * 2 * tape->nr_pending_stages / tape->max_stages; + if (tape->nr_pending_stages >= tape->max_stages * 99 / 100) + tape->max_insert_speed = 5000; + } else if (tape->speed_control == 2) { + tape->max_insert_speed = tape->pipeline_head_speed * empty / 100 + + (tape->pipeline_head_speed * full / 100 - tape->pipeline_head_speed * empty / 100) * tape->nr_pending_stages / tape->max_stages; + } else + tape->max_insert_speed = tape->speed_control; + tape->max_insert_speed = max(tape->max_insert_speed, 500); +} + +static ide_startstop_t idetape_media_access_finished (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc = tape->pc; + atapi_status_t status; + + status.all = HWIF(drive)->INB(IDE_STATUS_REG); + if (status.b.dsc) { + if (status.b.check) { + /* Error detected */ + if (pc->c[0] != IDETAPE_TEST_UNIT_READY_CMD) + printk(KERN_ERR "ide-tape: %s: I/O error, ", + tape->name); + /* Retry operation */ + return idetape_retry_pc(drive); + } + pc->error = 0; + if (tape->failed_pc == pc) + tape->failed_pc = NULL; + } else { + pc->error = IDETAPE_ERROR_GENERAL; + tape->failed_pc = NULL; + } + return pc->callback(drive); +} + +static ide_startstop_t idetape_rw_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + struct request *rq = HWGROUP(drive)->rq; + int blocks = tape->pc->actually_transferred / tape->tape_block_size; + + tape->avg_size += blocks * tape->tape_block_size; + tape->insert_size += blocks * tape->tape_block_size; + if (tape->insert_size > 1024 * 1024) + tape->measure_insert_time = 1; + if (tape->measure_insert_time) { + tape->measure_insert_time = 0; + tape->insert_time = jiffies; + tape->insert_size = 0; + } + if (time_after(jiffies, tape->insert_time)) + tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time); + if (jiffies - tape->avg_time >= HZ) { + tape->avg_speed = tape->avg_size * HZ / (jiffies - tape->avg_time) / 1024; + tape->avg_size = 0; + tape->avg_time = jiffies; + } + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_rw_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + tape->first_frame_position += blocks; + rq->current_nr_sectors -= blocks; + + if (!tape->pc->error) + idetape_end_request(drive, 1, 0); + else + idetape_end_request(drive, tape->pc->error, 0); + return ide_stopped; +} + +static void idetape_create_read_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_READ_CMD; + put_unaligned(htonl(length), (unsigned int *) &pc->c[1]); + pc->c[1] = 1; + pc->callback = &idetape_rw_callback; + pc->bh = bh; + atomic_set(&bh->b_count, 0); + pc->buffer = NULL; + pc->request_transfer = pc->buffer_size = length * tape->tape_block_size; + if (pc->request_transfer == tape->stage_size) + set_bit(PC_DMA_RECOMMENDED, &pc->flags); +} + +static void idetape_create_read_buffer_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh) +{ + int size = 32768; + struct idetape_bh *p = bh; + + idetape_init_pc(pc); + pc->c[0] = IDETAPE_READ_BUFFER_CMD; + pc->c[1] = IDETAPE_RETRIEVE_FAULTY_BLOCK; + pc->c[7] = size >> 8; + pc->c[8] = size & 0xff; + pc->callback = &idetape_pc_callback; + pc->bh = bh; + atomic_set(&bh->b_count, 0); + pc->buffer = NULL; + while (p) { + atomic_set(&p->b_count, 0); + p = p->b_reqnext; + } + pc->request_transfer = pc->buffer_size = size; +} + +static void idetape_create_write_cmd(idetape_tape_t *tape, idetape_pc_t *pc, unsigned int length, struct idetape_bh *bh) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_WRITE_CMD; + put_unaligned(htonl(length), (unsigned int *) &pc->c[1]); + pc->c[1] = 1; + pc->callback = &idetape_rw_callback; + set_bit(PC_WRITING, &pc->flags); + pc->bh = bh; + pc->b_data = bh->b_data; + pc->b_count = atomic_read(&bh->b_count); + pc->buffer = NULL; + pc->request_transfer = pc->buffer_size = length * tape->tape_block_size; + if (pc->request_transfer == tape->stage_size) + set_bit(PC_DMA_RECOMMENDED, &pc->flags); +} + +/* + * idetape_do_request is our request handling function. + */ +static ide_startstop_t idetape_do_request(ide_drive_t *drive, + struct request *rq, sector_t block) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t *pc = NULL; + struct request *postponed_rq = tape->postponed_rq; + atapi_status_t status; + +#if IDETAPE_DEBUG_LOG +#if 0 + if (tape->debug_level >= 5) + printk(KERN_INFO "ide-tape: rq_status: %d, " + "dev: %s, cmd: %ld, errors: %d\n", rq->rq_status, + rq->rq_disk->disk_name, rq->cmd[0], rq->errors); +#endif + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: sector: %ld, " + "nr_sectors: %ld, current_nr_sectors: %d\n", + rq->sector, rq->nr_sectors, rq->current_nr_sectors); +#endif /* IDETAPE_DEBUG_LOG */ + + if ((rq->flags & REQ_SPECIAL) == 0) { + /* + * We do not support buffer cache originated requests. + */ + printk(KERN_NOTICE "ide-tape: %s: Unsupported request in " + "request queue (%ld)\n", drive->name, rq->flags); + ide_end_request(drive, 0, 0); + return ide_stopped; + } + + /* + * Retry a failed packet command + */ + if (tape->failed_pc != NULL && + tape->pc->c[0] == IDETAPE_REQUEST_SENSE_CMD) { + return idetape_issue_packet_command(drive, tape->failed_pc); + } +#if IDETAPE_DEBUG_BUGS + if (postponed_rq != NULL) + if (rq != postponed_rq) { + printk(KERN_ERR "ide-tape: ide-tape.c bug - " + "Two DSC requests were queued\n"); + idetape_end_request(drive, 0, 0); + return ide_stopped; + } +#endif /* IDETAPE_DEBUG_BUGS */ + + tape->postponed_rq = NULL; + + /* + * If the tape is still busy, postpone our request and service + * the other device meanwhile. + */ + status.all = HWIF(drive)->INB(IDE_STATUS_REG); + + if (!drive->dsc_overlap && !(rq->cmd[0] & REQ_IDETAPE_PC2)) + set_bit(IDETAPE_IGNORE_DSC, &tape->flags); + + if (drive->post_reset == 1) { + set_bit(IDETAPE_IGNORE_DSC, &tape->flags); + drive->post_reset = 0; + } + + if (tape->tape_still_time > 100 && tape->tape_still_time < 200) + tape->measure_insert_time = 1; + if (time_after(jiffies, tape->insert_time)) + tape->insert_speed = tape->insert_size / 1024 * HZ / (jiffies - tape->insert_time); + calculate_speeds(drive); + if (!test_and_clear_bit(IDETAPE_IGNORE_DSC, &tape->flags) && + !status.b.dsc) { + if (postponed_rq == NULL) { + tape->dsc_polling_start = jiffies; + tape->dsc_polling_frequency = tape->best_dsc_rw_frequency; + tape->dsc_timeout = jiffies + IDETAPE_DSC_RW_TIMEOUT; + } else if (time_after(jiffies, tape->dsc_timeout)) { + printk(KERN_ERR "ide-tape: %s: DSC timeout\n", + tape->name); + if (rq->cmd[0] & REQ_IDETAPE_PC2) { + idetape_media_access_finished(drive); + return ide_stopped; + } else { + return ide_do_reset(drive); + } + } else if (jiffies - tape->dsc_polling_start > IDETAPE_DSC_MA_THRESHOLD) + tape->dsc_polling_frequency = IDETAPE_DSC_MA_SLOW; + idetape_postpone_request(drive); + return ide_stopped; + } + if (rq->cmd[0] & REQ_IDETAPE_READ) { + tape->buffer_head++; +#if USE_IOTRACE + IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor); +#endif + tape->postpone_cnt = 0; + pc = idetape_next_pc_storage(drive); + idetape_create_read_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special); + goto out; + } + if (rq->cmd[0] & REQ_IDETAPE_WRITE) { + tape->buffer_head++; +#if USE_IOTRACE + IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor); +#endif + tape->postpone_cnt = 0; + pc = idetape_next_pc_storage(drive); + idetape_create_write_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special); + goto out; + } + if (rq->cmd[0] & REQ_IDETAPE_READ_BUFFER) { + tape->postpone_cnt = 0; + pc = idetape_next_pc_storage(drive); + idetape_create_read_buffer_cmd(tape, pc, rq->current_nr_sectors, (struct idetape_bh *)rq->special); + goto out; + } + if (rq->cmd[0] & REQ_IDETAPE_PC1) { + pc = (idetape_pc_t *) rq->buffer; + rq->cmd[0] &= ~(REQ_IDETAPE_PC1); + rq->cmd[0] |= REQ_IDETAPE_PC2; + goto out; + } + if (rq->cmd[0] & REQ_IDETAPE_PC2) { + idetape_media_access_finished(drive); + return ide_stopped; + } + BUG(); +out: + return idetape_issue_packet_command(drive, pc); +} + +/* + * Pipeline related functions + */ +static inline int idetape_pipeline_active (idetape_tape_t *tape) +{ + int rc1, rc2; + + rc1 = test_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags); + rc2 = (tape->active_data_request != NULL); + return rc1; +} + +/* + * idetape_kmalloc_stage uses __get_free_page to allocate a pipeline + * stage, along with all the necessary small buffers which together make + * a buffer of size tape->stage_size (or a bit more). We attempt to + * combine sequential pages as much as possible. + * + * Returns a pointer to the new allocated stage, or NULL if we + * can't (or don't want to) allocate a stage. + * + * Pipeline stages are optional and are used to increase performance. + * If we can't allocate them, we'll manage without them. + */ +static idetape_stage_t *__idetape_kmalloc_stage (idetape_tape_t *tape, int full, int clear) +{ + idetape_stage_t *stage; + struct idetape_bh *prev_bh, *bh; + int pages = tape->pages_per_stage; + char *b_data = NULL; + + if ((stage = (idetape_stage_t *) kmalloc (sizeof (idetape_stage_t),GFP_KERNEL)) == NULL) + return NULL; + stage->next = NULL; + + bh = stage->bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL); + if (bh == NULL) + goto abort; + bh->b_reqnext = NULL; + if ((bh->b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL) + goto abort; + if (clear) + memset(bh->b_data, 0, PAGE_SIZE); + bh->b_size = PAGE_SIZE; + atomic_set(&bh->b_count, full ? bh->b_size : 0); + + while (--pages) { + if ((b_data = (char *) __get_free_page (GFP_KERNEL)) == NULL) + goto abort; + if (clear) + memset(b_data, 0, PAGE_SIZE); + if (bh->b_data == b_data + PAGE_SIZE) { + bh->b_size += PAGE_SIZE; + bh->b_data -= PAGE_SIZE; + if (full) + atomic_add(PAGE_SIZE, &bh->b_count); + continue; + } + if (b_data == bh->b_data + bh->b_size) { + bh->b_size += PAGE_SIZE; + if (full) + atomic_add(PAGE_SIZE, &bh->b_count); + continue; + } + prev_bh = bh; + if ((bh = (struct idetape_bh *)kmalloc(sizeof(struct idetape_bh), GFP_KERNEL)) == NULL) { + free_page((unsigned long) b_data); + goto abort; + } + bh->b_reqnext = NULL; + bh->b_data = b_data; + bh->b_size = PAGE_SIZE; + atomic_set(&bh->b_count, full ? bh->b_size : 0); + prev_bh->b_reqnext = bh; + } + bh->b_size -= tape->excess_bh_size; + if (full) + atomic_sub(tape->excess_bh_size, &bh->b_count); + return stage; +abort: + __idetape_kfree_stage(stage); + return NULL; +} + +static idetape_stage_t *idetape_kmalloc_stage (idetape_tape_t *tape) +{ + idetape_stage_t *cache_stage = tape->cache_stage; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_kmalloc_stage\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->nr_stages >= tape->max_stages) + return NULL; + if (cache_stage != NULL) { + tape->cache_stage = NULL; + return cache_stage; + } + return __idetape_kmalloc_stage(tape, 0, 0); +} + +static void idetape_copy_stage_from_user (idetape_tape_t *tape, idetape_stage_t *stage, const char __user *buf, int n) +{ + struct idetape_bh *bh = tape->bh; + int count; + + while (n) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk(KERN_ERR "ide-tape: bh == NULL in " + "idetape_copy_stage_from_user\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = min((unsigned int)(bh->b_size - atomic_read(&bh->b_count)), (unsigned int)n); + copy_from_user(bh->b_data + atomic_read(&bh->b_count), buf, count); + n -= count; + atomic_add(count, &bh->b_count); + buf += count; + if (atomic_read(&bh->b_count) == bh->b_size) { + bh = bh->b_reqnext; + if (bh) + atomic_set(&bh->b_count, 0); + } + } + tape->bh = bh; +} + +static void idetape_copy_stage_to_user (idetape_tape_t *tape, char __user *buf, idetape_stage_t *stage, int n) +{ + struct idetape_bh *bh = tape->bh; + int count; + + while (n) { +#if IDETAPE_DEBUG_BUGS + if (bh == NULL) { + printk(KERN_ERR "ide-tape: bh == NULL in " + "idetape_copy_stage_to_user\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + count = min(tape->b_count, n); + copy_to_user(buf, tape->b_data, count); + n -= count; + tape->b_data += count; + tape->b_count -= count; + buf += count; + if (!tape->b_count) { + tape->bh = bh = bh->b_reqnext; + if (bh) { + tape->b_data = bh->b_data; + tape->b_count = atomic_read(&bh->b_count); + } + } + } +} + +static void idetape_init_merge_stage (idetape_tape_t *tape) +{ + struct idetape_bh *bh = tape->merge_stage->bh; + + tape->bh = bh; + if (tape->chrdev_direction == idetape_direction_write) + atomic_set(&bh->b_count, 0); + else { + tape->b_data = bh->b_data; + tape->b_count = atomic_read(&bh->b_count); + } +} + +static void idetape_switch_buffers (idetape_tape_t *tape, idetape_stage_t *stage) +{ + struct idetape_bh *tmp; + + tmp = stage->bh; + stage->bh = tape->merge_stage->bh; + tape->merge_stage->bh = tmp; + idetape_init_merge_stage(tape); +} + +/* + * idetape_add_stage_tail adds a new stage at the end of the pipeline. + */ +static void idetape_add_stage_tail (ide_drive_t *drive,idetape_stage_t *stage) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk (KERN_INFO "ide-tape: Reached idetape_add_stage_tail\n"); +#endif /* IDETAPE_DEBUG_LOG */ + spin_lock_irqsave(&tape->spinlock, flags); + stage->next = NULL; + if (tape->last_stage != NULL) + tape->last_stage->next=stage; + else + tape->first_stage = tape->next_stage=stage; + tape->last_stage = stage; + if (tape->next_stage == NULL) + tape->next_stage = tape->last_stage; + tape->nr_stages++; + tape->nr_pending_stages++; + spin_unlock_irqrestore(&tape->spinlock, flags); +} + +/* + * idetape_wait_for_request installs a completion in a pending request + * and sleeps until it is serviced. + * + * The caller should ensure that the request will not be serviced + * before we install the completion (usually by disabling interrupts). + */ +static void idetape_wait_for_request (ide_drive_t *drive, struct request *rq) +{ + DECLARE_COMPLETION(wait); + idetape_tape_t *tape = drive->driver_data; + +#if IDETAPE_DEBUG_BUGS + if (rq == NULL || (rq->flags & REQ_SPECIAL) == 0) { + printk (KERN_ERR "ide-tape: bug: Trying to sleep on non-valid request\n"); + return; + } +#endif /* IDETAPE_DEBUG_BUGS */ + rq->waiting = &wait; + rq->end_io = blk_end_sync_rq; + spin_unlock_irq(&tape->spinlock); + wait_for_completion(&wait); + /* The stage and its struct request have been deallocated */ + spin_lock_irq(&tape->spinlock); +} + +static ide_startstop_t idetape_read_position_callback (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_read_position_result_t *result; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_read_position_callback\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (!tape->pc->error) { + result = (idetape_read_position_result_t *) tape->pc->buffer; +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: BOP - %s\n",result->bop ? "Yes":"No"); + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: EOP - %s\n",result->eop ? "Yes":"No"); +#endif /* IDETAPE_DEBUG_LOG */ + if (result->bpu) { + printk(KERN_INFO "ide-tape: Block location is unknown to the tape\n"); + clear_bit(IDETAPE_ADDRESS_VALID, &tape->flags); + idetape_end_request(drive, 0, 0); + } else { +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: Block Location - %u\n", ntohl(result->first_block)); +#endif /* IDETAPE_DEBUG_LOG */ + tape->partition = result->partition; + tape->first_frame_position = ntohl(result->first_block); + tape->last_frame_position = ntohl(result->last_block); + tape->blocks_in_buffer = result->blocks_in_buffer[2]; + set_bit(IDETAPE_ADDRESS_VALID, &tape->flags); + idetape_end_request(drive, 1, 0); + } + } else { + idetape_end_request(drive, 0, 0); + } + return ide_stopped; +} + +/* + * idetape_create_write_filemark_cmd will: + * + * 1. Write a filemark if write_filemark=1. + * 2. Flush the device buffers without writing a filemark + * if write_filemark=0. + * + */ +static void idetape_create_write_filemark_cmd (ide_drive_t *drive, idetape_pc_t *pc,int write_filemark) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_WRITE_FILEMARK_CMD; + pc->c[4] = write_filemark; + set_bit(PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_test_unit_ready_cmd(idetape_pc_t *pc) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_TEST_UNIT_READY_CMD; + pc->callback = &idetape_pc_callback; +} + +/* + * idetape_queue_pc_tail is based on the following functions: + * + * ide_do_drive_cmd from ide.c + * cdrom_queue_request and cdrom_queue_packet_command from ide-cd.c + * + * We add a special packet command request to the tail of the request + * queue, and wait for it to be serviced. + * + * This is not to be called from within the request handling part + * of the driver ! We allocate here data in the stack, and it is valid + * until the request is finished. This is not the case for the bottom + * part of the driver, where we are always leaving the functions to wait + * for an interrupt or a timer event. + * + * From the bottom part of the driver, we should allocate safe memory + * using idetape_next_pc_storage and idetape_next_rq_storage, and add + * the request to the request list without waiting for it to be serviced ! + * In that case, we usually use idetape_queue_pc_head. + */ +static int __idetape_queue_pc_tail (ide_drive_t *drive, idetape_pc_t *pc) +{ + struct ide_tape_obj *tape = drive->driver_data; + struct request rq; + + idetape_init_rq(&rq, REQ_IDETAPE_PC1); + rq.buffer = (char *) pc; + rq.rq_disk = tape->disk; + return ide_do_drive_cmd(drive, &rq, ide_wait); +} + +static void idetape_create_load_unload_cmd (ide_drive_t *drive, idetape_pc_t *pc,int cmd) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_LOAD_UNLOAD_CMD; + pc->c[4] = cmd; + set_bit(PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static int idetape_wait_ready(ide_drive_t *drive, unsigned long timeout) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + int load_attempted = 0; + + /* + * Wait for the tape to become ready + */ + set_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags); + timeout += jiffies; + while (time_before(jiffies, timeout)) { + idetape_create_test_unit_ready_cmd(&pc); + if (!__idetape_queue_pc_tail(drive, &pc)) + return 0; + if ((tape->sense_key == 2 && tape->asc == 4 && tape->ascq == 2) + || (tape->asc == 0x3A)) { /* no media */ + if (load_attempted) + return -ENOMEDIUM; + idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK); + __idetape_queue_pc_tail(drive, &pc); + load_attempted = 1; + /* not about to be ready */ + } else if (!(tape->sense_key == 2 && tape->asc == 4 && + (tape->ascq == 1 || tape->ascq == 8))) + return -EIO; + current->state = TASK_INTERRUPTIBLE; + schedule_timeout(HZ / 10); + } + return -EIO; +} + +static int idetape_queue_pc_tail (ide_drive_t *drive,idetape_pc_t *pc) +{ + return __idetape_queue_pc_tail(drive, pc); +} + +static int idetape_flush_tape_buffers (ide_drive_t *drive) +{ + idetape_pc_t pc; + int rc; + + idetape_create_write_filemark_cmd(drive, &pc, 0); + if ((rc = idetape_queue_pc_tail(drive, &pc))) + return rc; + idetape_wait_ready(drive, 60 * 5 * HZ); + return 0; +} + +static void idetape_create_read_position_cmd (idetape_pc_t *pc) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_READ_POSITION_CMD; + pc->request_transfer = 20; + pc->callback = &idetape_read_position_callback; +} + +static int idetape_read_position (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + int position; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_read_position\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + idetape_create_read_position_cmd(&pc); + if (idetape_queue_pc_tail(drive, &pc)) + return -1; + position = tape->first_frame_position; + return position; +} + +static void idetape_create_locate_cmd (ide_drive_t *drive, idetape_pc_t *pc, unsigned int block, u8 partition, int skip) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_LOCATE_CMD; + pc->c[1] = 2; + put_unaligned(htonl(block), (unsigned int *) &pc->c[3]); + pc->c[8] = partition; + set_bit(PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static int idetape_create_prevent_cmd (ide_drive_t *drive, idetape_pc_t *pc, int prevent) +{ + idetape_tape_t *tape = drive->driver_data; + + if (!tape->capabilities.lock) + return 0; + + idetape_init_pc(pc); + pc->c[0] = IDETAPE_PREVENT_CMD; + pc->c[4] = prevent; + pc->callback = &idetape_pc_callback; + return 1; +} + +static int __idetape_discard_read_pipeline (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + int cnt; + + if (tape->chrdev_direction != idetape_direction_read) + return 0; + + /* Remove merge stage. */ + cnt = tape->merge_stage_size / tape->tape_block_size; + if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags)) + ++cnt; /* Filemarks count as 1 sector */ + tape->merge_stage_size = 0; + if (tape->merge_stage != NULL) { + __idetape_kfree_stage(tape->merge_stage); + tape->merge_stage = NULL; + } + + /* Clear pipeline flags. */ + clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); + tape->chrdev_direction = idetape_direction_none; + + /* Remove pipeline stages. */ + if (tape->first_stage == NULL) + return 0; + + spin_lock_irqsave(&tape->spinlock, flags); + tape->next_stage = NULL; + if (idetape_pipeline_active(tape)) + idetape_wait_for_request(drive, tape->active_data_request); + spin_unlock_irqrestore(&tape->spinlock, flags); + + while (tape->first_stage != NULL) { + struct request *rq_ptr = &tape->first_stage->rq; + + cnt += rq_ptr->nr_sectors - rq_ptr->current_nr_sectors; + if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK) + ++cnt; + idetape_remove_stage_head(drive); + } + tape->nr_pending_stages = 0; + tape->max_stages = tape->min_pipeline; + return cnt; +} + +/* + * idetape_position_tape positions the tape to the requested block + * using the LOCATE packet command. A READ POSITION command is then + * issued to check where we are positioned. + * + * Like all higher level operations, we queue the commands at the tail + * of the request queue and wait for their completion. + * + */ +static int idetape_position_tape (ide_drive_t *drive, unsigned int block, u8 partition, int skip) +{ + idetape_tape_t *tape = drive->driver_data; + int retval; + idetape_pc_t pc; + + if (tape->chrdev_direction == idetape_direction_read) + __idetape_discard_read_pipeline(drive); + idetape_wait_ready(drive, 60 * 5 * HZ); + idetape_create_locate_cmd(drive, &pc, block, partition, skip); + retval = idetape_queue_pc_tail(drive, &pc); + if (retval) + return (retval); + + idetape_create_read_position_cmd(&pc); + return (idetape_queue_pc_tail(drive, &pc)); +} + +static void idetape_discard_read_pipeline (ide_drive_t *drive, int restore_position) +{ + idetape_tape_t *tape = drive->driver_data; + int cnt; + int seek, position; + + cnt = __idetape_discard_read_pipeline(drive); + if (restore_position) { + position = idetape_read_position(drive); + seek = position > cnt ? position - cnt : 0; + if (idetape_position_tape(drive, seek, 0, 0)) { + printk(KERN_INFO "ide-tape: %s: position_tape failed in discard_pipeline()\n", tape->name); + return; + } + } +} + +/* + * idetape_queue_rw_tail generates a read/write request for the block + * device interface and wait for it to be serviced. + */ +static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int blocks, struct idetape_bh *bh) +{ + idetape_tape_t *tape = drive->driver_data; + struct request rq; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: idetape_queue_rw_tail: cmd=%d\n",cmd); +#endif /* IDETAPE_DEBUG_LOG */ +#if IDETAPE_DEBUG_BUGS + if (idetape_pipeline_active(tape)) { + printk(KERN_ERR "ide-tape: bug: the pipeline is active in idetape_queue_rw_tail\n"); + return (0); + } +#endif /* IDETAPE_DEBUG_BUGS */ + + idetape_init_rq(&rq, cmd); + rq.rq_disk = tape->disk; + rq.special = (void *)bh; + rq.sector = tape->first_frame_position; + rq.nr_sectors = rq.current_nr_sectors = blocks; + (void) ide_do_drive_cmd(drive, &rq, ide_wait); + + if ((cmd & (REQ_IDETAPE_READ | REQ_IDETAPE_WRITE)) == 0) + return 0; + + if (tape->merge_stage) + idetape_init_merge_stage(tape); + if (rq.errors == IDETAPE_ERROR_GENERAL) + return -EIO; + return (tape->tape_block_size * (blocks-rq.current_nr_sectors)); +} + +/* + * idetape_insert_pipeline_into_queue is used to start servicing the + * pipeline stages, starting from tape->next_stage. + */ +static void idetape_insert_pipeline_into_queue (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + + if (tape->next_stage == NULL) + return; + if (!idetape_pipeline_active(tape)) { + set_bit(IDETAPE_PIPELINE_ACTIVE, &tape->flags); + idetape_active_next_stage(drive); + (void) ide_do_drive_cmd(drive, tape->active_data_request, ide_end); + } +} + +static void idetape_create_inquiry_cmd (idetape_pc_t *pc) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_INQUIRY_CMD; + pc->c[4] = pc->request_transfer = 254; + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_rewind_cmd (ide_drive_t *drive, idetape_pc_t *pc) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_REWIND_CMD; + set_bit(PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +#if 0 +static void idetape_create_mode_select_cmd (idetape_pc_t *pc, int length) +{ + idetape_init_pc(pc); + set_bit(PC_WRITING, &pc->flags); + pc->c[0] = IDETAPE_MODE_SELECT_CMD; + pc->c[1] = 0x10; + put_unaligned(htons(length), (unsigned short *) &pc->c[3]); + pc->request_transfer = 255; + pc->callback = &idetape_pc_callback; +} +#endif + +static void idetape_create_erase_cmd (idetape_pc_t *pc) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_ERASE_CMD; + pc->c[1] = 1; + set_bit(PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_create_space_cmd (idetape_pc_t *pc,int count, u8 cmd) +{ + idetape_init_pc(pc); + pc->c[0] = IDETAPE_SPACE_CMD; + put_unaligned(htonl(count), (unsigned int *) &pc->c[1]); + pc->c[1] = cmd; + set_bit(PC_WAIT_FOR_DSC, &pc->flags); + pc->callback = &idetape_pc_callback; +} + +static void idetape_wait_first_stage (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + + if (tape->first_stage == NULL) + return; + spin_lock_irqsave(&tape->spinlock, flags); + if (tape->active_stage == tape->first_stage) + idetape_wait_for_request(drive, tape->active_data_request); + spin_unlock_irqrestore(&tape->spinlock, flags); +} + +/* + * idetape_add_chrdev_write_request tries to add a character device + * originated write request to our pipeline. In case we don't succeed, + * we revert to non-pipelined operation mode for this request. + * + * 1. Try to allocate a new pipeline stage. + * 2. If we can't, wait for more and more requests to be serviced + * and try again each time. + * 3. If we still can't allocate a stage, fallback to + * non-pipelined operation mode for this request. + */ +static int idetape_add_chrdev_write_request (ide_drive_t *drive, int blocks) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *new_stage; + unsigned long flags; + struct request *rq; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 3) + printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_write_request\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + /* + * Attempt to allocate a new stage. + * Pay special attention to possible race conditions. + */ + while ((new_stage = idetape_kmalloc_stage(tape)) == NULL) { + spin_lock_irqsave(&tape->spinlock, flags); + if (idetape_pipeline_active(tape)) { + idetape_wait_for_request(drive, tape->active_data_request); + spin_unlock_irqrestore(&tape->spinlock, flags); + } else { + spin_unlock_irqrestore(&tape->spinlock, flags); + idetape_insert_pipeline_into_queue(drive); + if (idetape_pipeline_active(tape)) + continue; + /* + * Linux is short on memory. Fallback to + * non-pipelined operation mode for this request. + */ + return idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh); + } + } + rq = &new_stage->rq; + idetape_init_rq(rq, REQ_IDETAPE_WRITE); + /* Doesn't actually matter - We always assume sequential access */ + rq->sector = tape->first_frame_position; + rq->nr_sectors = rq->current_nr_sectors = blocks; + + idetape_switch_buffers(tape, new_stage); + idetape_add_stage_tail(drive, new_stage); + tape->pipeline_head++; +#if USE_IOTRACE + IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor); +#endif + calculate_speeds(drive); + + /* + * Estimate whether the tape has stopped writing by checking + * if our write pipeline is currently empty. If we are not + * writing anymore, wait for the pipeline to be full enough + * (90%) before starting to service requests, so that we will + * be able to keep up with the higher speeds of the tape. + */ + if (!idetape_pipeline_active(tape)) { + if (tape->nr_stages >= tape->max_stages * 9 / 10 || + tape->nr_stages >= tape->max_stages - tape->uncontrolled_pipeline_head_speed * 3 * 1024 / tape->tape_block_size) { + tape->measure_insert_time = 1; + tape->insert_time = jiffies; + tape->insert_size = 0; + tape->insert_speed = 0; + idetape_insert_pipeline_into_queue(drive); + } + } + if (test_and_clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags)) + /* Return a deferred error */ + return -EIO; + return blocks; +} + +/* + * idetape_wait_for_pipeline will wait until all pending pipeline + * requests are serviced. Typically called on device close. + */ +static void idetape_wait_for_pipeline (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + + while (tape->next_stage || idetape_pipeline_active(tape)) { + idetape_insert_pipeline_into_queue(drive); + spin_lock_irqsave(&tape->spinlock, flags); + if (idetape_pipeline_active(tape)) + idetape_wait_for_request(drive, tape->active_data_request); + spin_unlock_irqrestore(&tape->spinlock, flags); + } +} + +static void idetape_empty_write_pipeline (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + int blocks, min; + struct idetape_bh *bh; + +#if IDETAPE_DEBUG_BUGS + if (tape->chrdev_direction != idetape_direction_write) { + printk(KERN_ERR "ide-tape: bug: Trying to empty write pipeline, but we are not writing.\n"); + return; + } + if (tape->merge_stage_size > tape->stage_size) { + printk(KERN_ERR "ide-tape: bug: merge_buffer too big\n"); + tape->merge_stage_size = tape->stage_size; + } +#endif /* IDETAPE_DEBUG_BUGS */ + if (tape->merge_stage_size) { + blocks = tape->merge_stage_size / tape->tape_block_size; + if (tape->merge_stage_size % tape->tape_block_size) { + unsigned int i; + + blocks++; + i = tape->tape_block_size - tape->merge_stage_size % tape->tape_block_size; + bh = tape->bh->b_reqnext; + while (bh) { + atomic_set(&bh->b_count, 0); + bh = bh->b_reqnext; + } + bh = tape->bh; + while (i) { + if (bh == NULL) { + + printk(KERN_INFO "ide-tape: bug, bh NULL\n"); + break; + } + min = min(i, (unsigned int)(bh->b_size - atomic_read(&bh->b_count))); + memset(bh->b_data + atomic_read(&bh->b_count), 0, min); + atomic_add(min, &bh->b_count); + i -= min; + bh = bh->b_reqnext; + } + } + (void) idetape_add_chrdev_write_request(drive, blocks); + tape->merge_stage_size = 0; + } + idetape_wait_for_pipeline(drive); + if (tape->merge_stage != NULL) { + __idetape_kfree_stage(tape->merge_stage); + tape->merge_stage = NULL; + } + clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); + tape->chrdev_direction = idetape_direction_none; + + /* + * On the next backup, perform the feedback loop again. + * (I don't want to keep sense information between backups, + * as some systems are constantly on, and the system load + * can be totally different on the next backup). + */ + tape->max_stages = tape->min_pipeline; +#if IDETAPE_DEBUG_BUGS + if (tape->first_stage != NULL || + tape->next_stage != NULL || + tape->last_stage != NULL || + tape->nr_stages != 0) { + printk(KERN_ERR "ide-tape: ide-tape pipeline bug, " + "first_stage %p, next_stage %p, " + "last_stage %p, nr_stages %d\n", + tape->first_stage, tape->next_stage, + tape->last_stage, tape->nr_stages); + } +#endif /* IDETAPE_DEBUG_BUGS */ +} + +static void idetape_restart_speed_control (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + + tape->restart_speed_control_req = 0; + tape->pipeline_head = 0; + tape->controlled_last_pipeline_head = tape->uncontrolled_last_pipeline_head = 0; + tape->controlled_previous_pipeline_head = tape->uncontrolled_previous_pipeline_head = 0; + tape->pipeline_head_speed = tape->controlled_pipeline_head_speed = 5000; + tape->uncontrolled_pipeline_head_speed = 0; + tape->controlled_pipeline_head_time = tape->uncontrolled_pipeline_head_time = jiffies; + tape->controlled_previous_head_time = tape->uncontrolled_previous_head_time = jiffies; +} + +static int idetape_initiate_read (ide_drive_t *drive, int max_stages) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *new_stage; + struct request rq; + int bytes_read; + int blocks = tape->capabilities.ctl; + + /* Initialize read operation */ + if (tape->chrdev_direction != idetape_direction_read) { + if (tape->chrdev_direction == idetape_direction_write) { + idetape_empty_write_pipeline(drive); + idetape_flush_tape_buffers(drive); + } +#if IDETAPE_DEBUG_BUGS + if (tape->merge_stage || tape->merge_stage_size) { + printk (KERN_ERR "ide-tape: merge_stage_size should be 0 now\n"); + tape->merge_stage_size = 0; + } +#endif /* IDETAPE_DEBUG_BUGS */ + if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL) + return -ENOMEM; + tape->chrdev_direction = idetape_direction_read; + + /* + * Issue a read 0 command to ensure that DSC handshake + * is switched from completion mode to buffer available + * mode. + * No point in issuing this if DSC overlap isn't supported, + * some drives (Seagate STT3401A) will return an error. + */ + if (drive->dsc_overlap) { + bytes_read = idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, 0, tape->merge_stage->bh); + if (bytes_read < 0) { + __idetape_kfree_stage(tape->merge_stage); + tape->merge_stage = NULL; + tape->chrdev_direction = idetape_direction_none; + return bytes_read; + } + } + } + if (tape->restart_speed_control_req) + idetape_restart_speed_control(drive); + idetape_init_rq(&rq, REQ_IDETAPE_READ); + rq.sector = tape->first_frame_position; + rq.nr_sectors = rq.current_nr_sectors = blocks; + if (!test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags) && + tape->nr_stages < max_stages) { + new_stage = idetape_kmalloc_stage(tape); + while (new_stage != NULL) { + new_stage->rq = rq; + idetape_add_stage_tail(drive, new_stage); + if (tape->nr_stages >= max_stages) + break; + new_stage = idetape_kmalloc_stage(tape); + } + } + if (!idetape_pipeline_active(tape)) { + if (tape->nr_pending_stages >= 3 * max_stages / 4) { + tape->measure_insert_time = 1; + tape->insert_time = jiffies; + tape->insert_size = 0; + tape->insert_speed = 0; + idetape_insert_pipeline_into_queue(drive); + } + } + return 0; +} + +/* + * idetape_add_chrdev_read_request is called from idetape_chrdev_read + * to service a character device read request and add read-ahead + * requests to our pipeline. + */ +static int idetape_add_chrdev_read_request (ide_drive_t *drive,int blocks) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + struct request *rq_ptr; + int bytes_read; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_add_chrdev_read_request, %d blocks\n", blocks); +#endif /* IDETAPE_DEBUG_LOG */ + + /* + * If we are at a filemark, return a read length of 0 + */ + if (test_bit(IDETAPE_FILEMARK, &tape->flags)) + return 0; + + /* + * Wait for the next block to be available at the head + * of the pipeline + */ + idetape_initiate_read(drive, tape->max_stages); + if (tape->first_stage == NULL) { + if (test_bit(IDETAPE_PIPELINE_ERROR, &tape->flags)) + return 0; + return idetape_queue_rw_tail(drive, REQ_IDETAPE_READ, blocks, tape->merge_stage->bh); + } + idetape_wait_first_stage(drive); + rq_ptr = &tape->first_stage->rq; + bytes_read = tape->tape_block_size * (rq_ptr->nr_sectors - rq_ptr->current_nr_sectors); + rq_ptr->nr_sectors = rq_ptr->current_nr_sectors = 0; + + + if (rq_ptr->errors == IDETAPE_ERROR_EOD) + return 0; + else { + idetape_switch_buffers(tape, tape->first_stage); + if (rq_ptr->errors == IDETAPE_ERROR_FILEMARK) + set_bit(IDETAPE_FILEMARK, &tape->flags); + spin_lock_irqsave(&tape->spinlock, flags); + idetape_remove_stage_head(drive); + spin_unlock_irqrestore(&tape->spinlock, flags); + tape->pipeline_head++; +#if USE_IOTRACE + IO_trace(IO_IDETAPE_FIFO, tape->pipeline_head, tape->buffer_head, tape->tape_head, tape->minor); +#endif + calculate_speeds(drive); + } +#if IDETAPE_DEBUG_BUGS + if (bytes_read > blocks * tape->tape_block_size) { + printk(KERN_ERR "ide-tape: bug: trying to return more bytes than requested\n"); + bytes_read = blocks * tape->tape_block_size; + } +#endif /* IDETAPE_DEBUG_BUGS */ + return (bytes_read); +} + +static void idetape_pad_zeros (ide_drive_t *drive, int bcount) +{ + idetape_tape_t *tape = drive->driver_data; + struct idetape_bh *bh; + int blocks; + + while (bcount) { + unsigned int count; + + bh = tape->merge_stage->bh; + count = min(tape->stage_size, bcount); + bcount -= count; + blocks = count / tape->tape_block_size; + while (count) { + atomic_set(&bh->b_count, min(count, (unsigned int)bh->b_size)); + memset(bh->b_data, 0, atomic_read(&bh->b_count)); + count -= atomic_read(&bh->b_count); + bh = bh->b_reqnext; + } + idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, blocks, tape->merge_stage->bh); + } +} + +static int idetape_pipeline_size (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_stage_t *stage; + struct request *rq; + int size = 0; + + idetape_wait_for_pipeline(drive); + stage = tape->first_stage; + while (stage != NULL) { + rq = &stage->rq; + size += tape->tape_block_size * (rq->nr_sectors-rq->current_nr_sectors); + if (rq->errors == IDETAPE_ERROR_FILEMARK) + size += tape->tape_block_size; + stage = stage->next; + } + size += tape->merge_stage_size; + return size; +} + +/* + * Rewinds the tape to the Beginning Of the current Partition (BOP). + * + * We currently support only one partition. + */ +static int idetape_rewind_tape (ide_drive_t *drive) +{ + int retval; + idetape_pc_t pc; +#if IDETAPE_DEBUG_LOG + idetape_tape_t *tape = drive->driver_data; + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: Reached idetape_rewind_tape\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + idetape_create_rewind_cmd(drive, &pc); + retval = idetape_queue_pc_tail(drive, &pc); + if (retval) + return retval; + + idetape_create_read_position_cmd(&pc); + retval = idetape_queue_pc_tail(drive, &pc); + if (retval) + return retval; + return 0; +} + +/* + * Our special ide-tape ioctl's. + * + * Currently there aren't any ioctl's. + * mtio.h compatible commands should be issued to the character device + * interface. + */ +static int idetape_blkdev_ioctl(ide_drive_t *drive, unsigned int cmd, unsigned long arg) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_config_t config; + void __user *argp = (void __user *)arg; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 4) + printk(KERN_INFO "ide-tape: Reached idetape_blkdev_ioctl\n"); +#endif /* IDETAPE_DEBUG_LOG */ + switch (cmd) { + case 0x0340: + if (copy_from_user(&config, argp, sizeof (idetape_config_t))) + return -EFAULT; + tape->best_dsc_rw_frequency = config.dsc_rw_frequency; + tape->max_stages = config.nr_stages; + break; + case 0x0350: + config.dsc_rw_frequency = (int) tape->best_dsc_rw_frequency; + config.nr_stages = tape->max_stages; + if (copy_to_user(argp, &config, sizeof (idetape_config_t))) + return -EFAULT; + break; + default: + return -EIO; + } + return 0; +} + +/* + * idetape_space_over_filemarks is now a bit more complicated than just + * passing the command to the tape since we may have crossed some + * filemarks during our pipelined read-ahead mode. + * + * As a minor side effect, the pipeline enables us to support MTFSFM when + * the filemark is in our internal pipeline even if the tape doesn't + * support spacing over filemarks in the reverse direction. + */ +static int idetape_space_over_filemarks (ide_drive_t *drive,short mt_op,int mt_count) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + unsigned long flags; + int retval,count=0; + + if (mt_count == 0) + return 0; + if (MTBSF == mt_op || MTBSFM == mt_op) { + if (!tape->capabilities.sprev) + return -EIO; + mt_count = - mt_count; + } + + if (tape->chrdev_direction == idetape_direction_read) { + /* + * We have a read-ahead buffer. Scan it for crossed + * filemarks. + */ + tape->merge_stage_size = 0; + if (test_and_clear_bit(IDETAPE_FILEMARK, &tape->flags)) + ++count; + while (tape->first_stage != NULL) { + if (count == mt_count) { + if (mt_op == MTFSFM) + set_bit(IDETAPE_FILEMARK, &tape->flags); + return 0; + } + spin_lock_irqsave(&tape->spinlock, flags); + if (tape->first_stage == tape->active_stage) { + /* + * We have reached the active stage in the read pipeline. + * There is no point in allowing the drive to continue + * reading any farther, so we stop the pipeline. + * + * This section should be moved to a separate subroutine, + * because a similar function is performed in + * __idetape_discard_read_pipeline(), for example. + */ + tape->next_stage = NULL; + spin_unlock_irqrestore(&tape->spinlock, flags); + idetape_wait_first_stage(drive); + tape->next_stage = tape->first_stage->next; + } else + spin_unlock_irqrestore(&tape->spinlock, flags); + if (tape->first_stage->rq.errors == IDETAPE_ERROR_FILEMARK) + ++count; + idetape_remove_stage_head(drive); + } + idetape_discard_read_pipeline(drive, 0); + } + + /* + * The filemark was not found in our internal pipeline. + * Now we can issue the space command. + */ + switch (mt_op) { + case MTFSF: + case MTBSF: + idetape_create_space_cmd(&pc,mt_count-count,IDETAPE_SPACE_OVER_FILEMARK); + return (idetape_queue_pc_tail(drive, &pc)); + case MTFSFM: + case MTBSFM: + if (!tape->capabilities.sprev) + return (-EIO); + retval = idetape_space_over_filemarks(drive, MTFSF, mt_count-count); + if (retval) return (retval); + count = (MTBSFM == mt_op ? 1 : -1); + return (idetape_space_over_filemarks(drive, MTFSF, count)); + default: + printk(KERN_ERR "ide-tape: MTIO operation %d not supported\n",mt_op); + return (-EIO); + } +} + + +/* + * Our character device read / write functions. + * + * The tape is optimized to maximize throughput when it is transferring + * an integral number of the "continuous transfer limit", which is + * a parameter of the specific tape (26 KB on my particular tape). + * (32 kB for Onstream) + * + * As of version 1.3 of the driver, the character device provides an + * abstract continuous view of the media - any mix of block sizes (even 1 + * byte) on the same backup/restore procedure is supported. The driver + * will internally convert the requests to the recommended transfer unit, + * so that an unmatch between the user's block size to the recommended + * size will only result in a (slightly) increased driver overhead, but + * will no longer hit performance. + * This is not applicable to Onstream. + */ +static ssize_t idetape_chrdev_read (struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + struct ide_tape_obj *tape = ide_tape_f(file); + ide_drive_t *drive = tape->drive; + ssize_t bytes_read,temp, actually_read = 0, rc; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 3) + printk(KERN_INFO "ide-tape: Reached idetape_chrdev_read, count %Zd\n", count); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->chrdev_direction != idetape_direction_read) { + if (test_bit(IDETAPE_DETECT_BS, &tape->flags)) + if (count > tape->tape_block_size && + (count % tape->tape_block_size) == 0) + tape->user_bs_factor = count / tape->tape_block_size; + } + if ((rc = idetape_initiate_read(drive, tape->max_stages)) < 0) + return rc; + if (count == 0) + return (0); + if (tape->merge_stage_size) { + actually_read = min((unsigned int)(tape->merge_stage_size), (unsigned int)count); + idetape_copy_stage_to_user(tape, buf, tape->merge_stage, actually_read); + buf += actually_read; + tape->merge_stage_size -= actually_read; + count -= actually_read; + } + while (count >= tape->stage_size) { + bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl); + if (bytes_read <= 0) + goto finish; + idetape_copy_stage_to_user(tape, buf, tape->merge_stage, bytes_read); + buf += bytes_read; + count -= bytes_read; + actually_read += bytes_read; + } + if (count) { + bytes_read = idetape_add_chrdev_read_request(drive, tape->capabilities.ctl); + if (bytes_read <= 0) + goto finish; + temp = min((unsigned long)count, (unsigned long)bytes_read); + idetape_copy_stage_to_user(tape, buf, tape->merge_stage, temp); + actually_read += temp; + tape->merge_stage_size = bytes_read-temp; + } +finish: + if (!actually_read && test_bit(IDETAPE_FILEMARK, &tape->flags)) { +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 2) + printk(KERN_INFO "ide-tape: %s: spacing over filemark\n", tape->name); +#endif + idetape_space_over_filemarks(drive, MTFSF, 1); + return 0; + } + return actually_read; +} + +static ssize_t idetape_chrdev_write (struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + struct ide_tape_obj *tape = ide_tape_f(file); + ide_drive_t *drive = tape->drive; + ssize_t retval, actually_written = 0; + + /* The drive is write protected. */ + if (tape->write_prot) + return -EACCES; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 3) + printk(KERN_INFO "ide-tape: Reached idetape_chrdev_write, " + "count %Zd\n", count); +#endif /* IDETAPE_DEBUG_LOG */ + + /* Initialize write operation */ + if (tape->chrdev_direction != idetape_direction_write) { + if (tape->chrdev_direction == idetape_direction_read) + idetape_discard_read_pipeline(drive, 1); +#if IDETAPE_DEBUG_BUGS + if (tape->merge_stage || tape->merge_stage_size) { + printk(KERN_ERR "ide-tape: merge_stage_size " + "should be 0 now\n"); + tape->merge_stage_size = 0; + } +#endif /* IDETAPE_DEBUG_BUGS */ + if ((tape->merge_stage = __idetape_kmalloc_stage(tape, 0, 0)) == NULL) + return -ENOMEM; + tape->chrdev_direction = idetape_direction_write; + idetape_init_merge_stage(tape); + + /* + * Issue a write 0 command to ensure that DSC handshake + * is switched from completion mode to buffer available + * mode. + * No point in issuing this if DSC overlap isn't supported, + * some drives (Seagate STT3401A) will return an error. + */ + if (drive->dsc_overlap) { + retval = idetape_queue_rw_tail(drive, REQ_IDETAPE_WRITE, 0, tape->merge_stage->bh); + if (retval < 0) { + __idetape_kfree_stage(tape->merge_stage); + tape->merge_stage = NULL; + tape->chrdev_direction = idetape_direction_none; + return retval; + } + } + } + if (count == 0) + return (0); + if (tape->restart_speed_control_req) + idetape_restart_speed_control(drive); + if (tape->merge_stage_size) { +#if IDETAPE_DEBUG_BUGS + if (tape->merge_stage_size >= tape->stage_size) { + printk(KERN_ERR "ide-tape: bug: merge buffer too big\n"); + tape->merge_stage_size = 0; + } +#endif /* IDETAPE_DEBUG_BUGS */ + actually_written = min((unsigned int)(tape->stage_size - tape->merge_stage_size), (unsigned int)count); + idetape_copy_stage_from_user(tape, tape->merge_stage, buf, actually_written); + buf += actually_written; + tape->merge_stage_size += actually_written; + count -= actually_written; + + if (tape->merge_stage_size == tape->stage_size) { + tape->merge_stage_size = 0; + retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl); + if (retval <= 0) + return (retval); + } + } + while (count >= tape->stage_size) { + idetape_copy_stage_from_user(tape, tape->merge_stage, buf, tape->stage_size); + buf += tape->stage_size; + count -= tape->stage_size; + retval = idetape_add_chrdev_write_request(drive, tape->capabilities.ctl); + actually_written += tape->stage_size; + if (retval <= 0) + return (retval); + } + if (count) { + actually_written += count; + idetape_copy_stage_from_user(tape, tape->merge_stage, buf, count); + tape->merge_stage_size += count; + } + return (actually_written); +} + +static int idetape_write_filemark (ide_drive_t *drive) +{ + idetape_pc_t pc; + + /* Write a filemark */ + idetape_create_write_filemark_cmd(drive, &pc, 1); + if (idetape_queue_pc_tail(drive, &pc)) { + printk(KERN_ERR "ide-tape: Couldn't write a filemark\n"); + return -EIO; + } + return 0; +} + +/* + * idetape_mtioctop is called from idetape_chrdev_ioctl when + * the general mtio MTIOCTOP ioctl is requested. + * + * We currently support the following mtio.h operations: + * + * MTFSF - Space over mt_count filemarks in the positive direction. + * The tape is positioned after the last spaced filemark. + * + * MTFSFM - Same as MTFSF, but the tape is positioned before the + * last filemark. + * + * MTBSF - Steps background over mt_count filemarks, tape is + * positioned before the last filemark. + * + * MTBSFM - Like MTBSF, only tape is positioned after the last filemark. + * + * Note: + * + * MTBSF and MTBSFM are not supported when the tape doesn't + * support spacing over filemarks in the reverse direction. + * In this case, MTFSFM is also usually not supported (it is + * supported in the rare case in which we crossed the filemark + * during our read-ahead pipelined operation mode). + * + * MTWEOF - Writes mt_count filemarks. Tape is positioned after + * the last written filemark. + * + * MTREW - Rewinds tape. + * + * MTLOAD - Loads the tape. + * + * MTOFFL - Puts the tape drive "Offline": Rewinds the tape and + * MTUNLOAD prevents further access until the media is replaced. + * + * MTNOP - Flushes tape buffers. + * + * MTRETEN - Retension media. This typically consists of one end + * to end pass on the media. + * + * MTEOM - Moves to the end of recorded data. + * + * MTERASE - Erases tape. + * + * MTSETBLK - Sets the user block size to mt_count bytes. If + * mt_count is 0, we will attempt to autodetect + * the block size. + * + * MTSEEK - Positions the tape in a specific block number, where + * each block is assumed to contain which user_block_size + * bytes. + * + * MTSETPART - Switches to another tape partition. + * + * MTLOCK - Locks the tape door. + * + * MTUNLOCK - Unlocks the tape door. + * + * The following commands are currently not supported: + * + * MTFSS, MTBSS, MTWSM, MTSETDENSITY, + * MTSETDRVBUFFER, MT_ST_BOOLEANS, MT_ST_WRITE_THRESHOLD. + */ +static int idetape_mtioctop (ide_drive_t *drive,short mt_op,int mt_count) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + int i,retval; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 1) + printk(KERN_INFO "ide-tape: Handling MTIOCTOP ioctl: " + "mt_op=%d, mt_count=%d\n", mt_op, mt_count); +#endif /* IDETAPE_DEBUG_LOG */ + /* + * Commands which need our pipelined read-ahead stages. + */ + switch (mt_op) { + case MTFSF: + case MTFSFM: + case MTBSF: + case MTBSFM: + if (!mt_count) + return (0); + return (idetape_space_over_filemarks(drive,mt_op,mt_count)); + default: + break; + } + switch (mt_op) { + case MTWEOF: + if (tape->write_prot) + return -EACCES; + idetape_discard_read_pipeline(drive, 1); + for (i = 0; i < mt_count; i++) { + retval = idetape_write_filemark(drive); + if (retval) + return retval; + } + return (0); + case MTREW: + idetape_discard_read_pipeline(drive, 0); + if (idetape_rewind_tape(drive)) + return -EIO; + return 0; + case MTLOAD: + idetape_discard_read_pipeline(drive, 0); + idetape_create_load_unload_cmd(drive, &pc, IDETAPE_LU_LOAD_MASK); + return (idetape_queue_pc_tail(drive, &pc)); + case MTUNLOAD: + case MTOFFL: + /* + * If door is locked, attempt to unlock before + * attempting to eject. + */ + if (tape->door_locked) { + if (idetape_create_prevent_cmd(drive, &pc, 0)) + if (!idetape_queue_pc_tail(drive, &pc)) + tape->door_locked = DOOR_UNLOCKED; + } + idetape_discard_read_pipeline(drive, 0); + idetape_create_load_unload_cmd(drive, &pc,!IDETAPE_LU_LOAD_MASK); + retval = idetape_queue_pc_tail(drive, &pc); + if (!retval) + clear_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags); + return retval; + case MTNOP: + idetape_discard_read_pipeline(drive, 0); + return (idetape_flush_tape_buffers(drive)); + case MTRETEN: + idetape_discard_read_pipeline(drive, 0); + idetape_create_load_unload_cmd(drive, &pc,IDETAPE_LU_RETENSION_MASK | IDETAPE_LU_LOAD_MASK); + return (idetape_queue_pc_tail(drive, &pc)); + case MTEOM: + idetape_create_space_cmd(&pc, 0, IDETAPE_SPACE_TO_EOD); + return (idetape_queue_pc_tail(drive, &pc)); + case MTERASE: + (void) idetape_rewind_tape(drive); + idetape_create_erase_cmd(&pc); + return (idetape_queue_pc_tail(drive, &pc)); + case MTSETBLK: + if (mt_count) { + if (mt_count < tape->tape_block_size || mt_count % tape->tape_block_size) + return -EIO; + tape->user_bs_factor = mt_count / tape->tape_block_size; + clear_bit(IDETAPE_DETECT_BS, &tape->flags); + } else + set_bit(IDETAPE_DETECT_BS, &tape->flags); + return 0; + case MTSEEK: + idetape_discard_read_pipeline(drive, 0); + return idetape_position_tape(drive, mt_count * tape->user_bs_factor, tape->partition, 0); + case MTSETPART: + idetape_discard_read_pipeline(drive, 0); + return (idetape_position_tape(drive, 0, mt_count, 0)); + case MTFSR: + case MTBSR: + case MTLOCK: + if (!idetape_create_prevent_cmd(drive, &pc, 1)) + return 0; + retval = idetape_queue_pc_tail(drive, &pc); + if (retval) return retval; + tape->door_locked = DOOR_EXPLICITLY_LOCKED; + return 0; + case MTUNLOCK: + if (!idetape_create_prevent_cmd(drive, &pc, 0)) + return 0; + retval = idetape_queue_pc_tail(drive, &pc); + if (retval) return retval; + tape->door_locked = DOOR_UNLOCKED; + return 0; + default: + printk(KERN_ERR "ide-tape: MTIO operation %d not " + "supported\n", mt_op); + return (-EIO); + } +} + +/* + * Our character device ioctls. + * + * General mtio.h magnetic io commands are supported here, and not in + * the corresponding block interface. + * + * The following ioctls are supported: + * + * MTIOCTOP - Refer to idetape_mtioctop for detailed description. + * + * MTIOCGET - The mt_dsreg field in the returned mtget structure + * will be set to (user block size in bytes << + * MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK. + * + * The mt_blkno is set to the current user block number. + * The other mtget fields are not supported. + * + * MTIOCPOS - The current tape "block position" is returned. We + * assume that each block contains user_block_size + * bytes. + * + * Our own ide-tape ioctls are supported on both interfaces. + */ +static int idetape_chrdev_ioctl (struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ide_tape_obj *tape = ide_tape_f(file); + ide_drive_t *drive = tape->drive; + struct mtop mtop; + struct mtget mtget; + struct mtpos mtpos; + int block_offset = 0, position = tape->first_frame_position; + void __user *argp = (void __user *)arg; + +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 3) + printk(KERN_INFO "ide-tape: Reached idetape_chrdev_ioctl, " + "cmd=%u\n", cmd); +#endif /* IDETAPE_DEBUG_LOG */ + + tape->restart_speed_control_req = 1; + if (tape->chrdev_direction == idetape_direction_write) { + idetape_empty_write_pipeline(drive); + idetape_flush_tape_buffers(drive); + } + if (cmd == MTIOCGET || cmd == MTIOCPOS) { + block_offset = idetape_pipeline_size(drive) / (tape->tape_block_size * tape->user_bs_factor); + if ((position = idetape_read_position(drive)) < 0) + return -EIO; + } + switch (cmd) { + case MTIOCTOP: + if (copy_from_user(&mtop, argp, sizeof (struct mtop))) + return -EFAULT; + return (idetape_mtioctop(drive,mtop.mt_op,mtop.mt_count)); + case MTIOCGET: + memset(&mtget, 0, sizeof (struct mtget)); + mtget.mt_type = MT_ISSCSI2; + mtget.mt_blkno = position / tape->user_bs_factor - block_offset; + mtget.mt_dsreg = ((tape->tape_block_size * tape->user_bs_factor) << MT_ST_BLKSIZE_SHIFT) & MT_ST_BLKSIZE_MASK; + if (tape->drv_write_prot) { + mtget.mt_gstat |= GMT_WR_PROT(0xffffffff); + } + if (copy_to_user(argp, &mtget, sizeof(struct mtget))) + return -EFAULT; + return 0; + case MTIOCPOS: + mtpos.mt_blkno = position / tape->user_bs_factor - block_offset; + if (copy_to_user(argp, &mtpos, sizeof(struct mtpos))) + return -EFAULT; + return 0; + default: + if (tape->chrdev_direction == idetape_direction_read) + idetape_discard_read_pipeline(drive, 1); + return idetape_blkdev_ioctl(drive, cmd, arg); + } +} + +static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive); + +/* + * Our character device open function. + */ +static int idetape_chrdev_open (struct inode *inode, struct file *filp) +{ + unsigned int minor = iminor(inode), i = minor & ~0xc0; + ide_drive_t *drive; + idetape_tape_t *tape; + idetape_pc_t pc; + int retval; + + /* + * We really want to do nonseekable_open(inode, filp); here, but some + * versions of tar incorrectly call lseek on tapes and bail out if that + * fails. So we disallow pread() and pwrite(), but permit lseeks. + */ + filp->f_mode &= ~(FMODE_PREAD | FMODE_PWRITE); + +#if IDETAPE_DEBUG_LOG + printk(KERN_INFO "ide-tape: Reached idetape_chrdev_open\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (i >= MAX_HWIFS * MAX_DRIVES) + return -ENXIO; + + if (!(tape = ide_tape_chrdev_get(i))) + return -ENXIO; + + drive = tape->drive; + + filp->private_data = tape; + + if (test_and_set_bit(IDETAPE_BUSY, &tape->flags)) { + retval = -EBUSY; + goto out_put_tape; + } + + retval = idetape_wait_ready(drive, 60 * HZ); + if (retval) { + clear_bit(IDETAPE_BUSY, &tape->flags); + printk(KERN_ERR "ide-tape: %s: drive not ready\n", tape->name); + goto out_put_tape; + } + + idetape_read_position(drive); + if (!test_bit(IDETAPE_ADDRESS_VALID, &tape->flags)) + (void)idetape_rewind_tape(drive); + + if (tape->chrdev_direction != idetape_direction_read) + clear_bit(IDETAPE_PIPELINE_ERROR, &tape->flags); + + /* Read block size and write protect status from drive. */ + idetape_get_blocksize_from_block_descriptor(drive); + + /* Set write protect flag if device is opened as read-only. */ + if ((filp->f_flags & O_ACCMODE) == O_RDONLY) + tape->write_prot = 1; + else + tape->write_prot = tape->drv_write_prot; + + /* Make sure drive isn't write protected if user wants to write. */ + if (tape->write_prot) { + if ((filp->f_flags & O_ACCMODE) == O_WRONLY || + (filp->f_flags & O_ACCMODE) == O_RDWR) { + clear_bit(IDETAPE_BUSY, &tape->flags); + retval = -EROFS; + goto out_put_tape; + } + } + + /* + * Lock the tape drive door so user can't eject. + */ + if (tape->chrdev_direction == idetape_direction_none) { + if (idetape_create_prevent_cmd(drive, &pc, 1)) { + if (!idetape_queue_pc_tail(drive, &pc)) { + if (tape->door_locked != DOOR_EXPLICITLY_LOCKED) + tape->door_locked = DOOR_LOCKED; + } + } + } + idetape_restart_speed_control(drive); + tape->restart_speed_control_req = 0; + return 0; + +out_put_tape: + ide_tape_put(tape); + return retval; +} + +static void idetape_write_release (ide_drive_t *drive, unsigned int minor) +{ + idetape_tape_t *tape = drive->driver_data; + + idetape_empty_write_pipeline(drive); + tape->merge_stage = __idetape_kmalloc_stage(tape, 1, 0); + if (tape->merge_stage != NULL) { + idetape_pad_zeros(drive, tape->tape_block_size * (tape->user_bs_factor - 1)); + __idetape_kfree_stage(tape->merge_stage); + tape->merge_stage = NULL; + } + idetape_write_filemark(drive); + idetape_flush_tape_buffers(drive); + idetape_flush_tape_buffers(drive); +} + +/* + * Our character device release function. + */ +static int idetape_chrdev_release (struct inode *inode, struct file *filp) +{ + struct ide_tape_obj *tape = ide_tape_f(filp); + ide_drive_t *drive = tape->drive; + idetape_pc_t pc; + unsigned int minor = iminor(inode); + + lock_kernel(); + tape = drive->driver_data; +#if IDETAPE_DEBUG_LOG + if (tape->debug_level >= 3) + printk(KERN_INFO "ide-tape: Reached idetape_chrdev_release\n"); +#endif /* IDETAPE_DEBUG_LOG */ + + if (tape->chrdev_direction == idetape_direction_write) + idetape_write_release(drive, minor); + if (tape->chrdev_direction == idetape_direction_read) { + if (minor < 128) + idetape_discard_read_pipeline(drive, 1); + else + idetape_wait_for_pipeline(drive); + } + if (tape->cache_stage != NULL) { + __idetape_kfree_stage(tape->cache_stage); + tape->cache_stage = NULL; + } + if (minor < 128 && test_bit(IDETAPE_MEDIUM_PRESENT, &tape->flags)) + (void) idetape_rewind_tape(drive); + if (tape->chrdev_direction == idetape_direction_none) { + if (tape->door_locked == DOOR_LOCKED) { + if (idetape_create_prevent_cmd(drive, &pc, 0)) { + if (!idetape_queue_pc_tail(drive, &pc)) + tape->door_locked = DOOR_UNLOCKED; + } + } + } + clear_bit(IDETAPE_BUSY, &tape->flags); + ide_tape_put(tape); + unlock_kernel(); + return 0; +} + +/* + * idetape_identify_device is called to check the contents of the + * ATAPI IDENTIFY command results. We return: + * + * 1 If the tape can be supported by us, based on the information + * we have so far. + * + * 0 If this tape driver is not currently supported by us. + */ +static int idetape_identify_device (ide_drive_t *drive) +{ + struct idetape_id_gcw gcw; + struct hd_driveid *id = drive->id; +#if IDETAPE_DEBUG_INFO + unsigned short mask,i; +#endif /* IDETAPE_DEBUG_INFO */ + + if (drive->id_read == 0) + return 1; + + *((unsigned short *) &gcw) = id->config; + +#if IDETAPE_DEBUG_INFO + printk(KERN_INFO "ide-tape: Dumping ATAPI Identify Device tape parameters\n"); + printk(KERN_INFO "ide-tape: Protocol Type: "); + switch (gcw.protocol) { + case 0: case 1: printk("ATA\n");break; + case 2: printk("ATAPI\n");break; + case 3: printk("Reserved (Unknown to ide-tape)\n");break; + } + printk(KERN_INFO "ide-tape: Device Type: %x - ",gcw.device_type); + switch (gcw.device_type) { + case 0: printk("Direct-access Device\n");break; + case 1: printk("Streaming Tape Device\n");break; + case 2: case 3: case 4: printk("Reserved\n");break; + case 5: printk("CD-ROM Device\n");break; + case 6: printk("Reserved\n"); + case 7: printk("Optical memory Device\n");break; + case 0x1f: printk("Unknown or no Device type\n");break; + default: printk("Reserved\n"); + } + printk(KERN_INFO "ide-tape: Removable: %s",gcw.removable ? "Yes\n":"No\n"); + printk(KERN_INFO "ide-tape: Command Packet DRQ Type: "); + switch (gcw.drq_type) { + case 0: printk("Microprocessor DRQ\n");break; + case 1: printk("Interrupt DRQ\n");break; + case 2: printk("Accelerated DRQ\n");break; + case 3: printk("Reserved\n");break; + } + printk(KERN_INFO "ide-tape: Command Packet Size: "); + switch (gcw.packet_size) { + case 0: printk("12 bytes\n");break; + case 1: printk("16 bytes\n");break; + default: printk("Reserved\n");break; + } + printk(KERN_INFO "ide-tape: Model: %.40s\n",id->model); + printk(KERN_INFO "ide-tape: Firmware Revision: %.8s\n",id->fw_rev); + printk(KERN_INFO "ide-tape: Serial Number: %.20s\n",id->serial_no); + printk(KERN_INFO "ide-tape: Write buffer size: %d bytes\n",id->buf_size*512); + printk(KERN_INFO "ide-tape: DMA: %s",id->capability & 0x01 ? "Yes\n":"No\n"); + printk(KERN_INFO "ide-tape: LBA: %s",id->capability & 0x02 ? "Yes\n":"No\n"); + printk(KERN_INFO "ide-tape: IORDY can be disabled: %s",id->capability & 0x04 ? "Yes\n":"No\n"); + printk(KERN_INFO "ide-tape: IORDY supported: %s",id->capability & 0x08 ? "Yes\n":"Unknown\n"); + printk(KERN_INFO "ide-tape: ATAPI overlap supported: %s",id->capability & 0x20 ? "Yes\n":"No\n"); + printk(KERN_INFO "ide-tape: PIO Cycle Timing Category: %d\n",id->tPIO); + printk(KERN_INFO "ide-tape: DMA Cycle Timing Category: %d\n",id->tDMA); + printk(KERN_INFO "ide-tape: Single Word DMA supported modes: "); + for (i=0,mask=1;i<8;i++,mask=mask << 1) { + if (id->dma_1word & mask) + printk("%d ",i); + if (id->dma_1word & (mask << 8)) + printk("(active) "); + } + printk("\n"); + printk(KERN_INFO "ide-tape: Multi Word DMA supported modes: "); + for (i=0,mask=1;i<8;i++,mask=mask << 1) { + if (id->dma_mword & mask) + printk("%d ",i); + if (id->dma_mword & (mask << 8)) + printk("(active) "); + } + printk("\n"); + if (id->field_valid & 0x0002) { + printk(KERN_INFO "ide-tape: Enhanced PIO Modes: %s\n", + id->eide_pio_modes & 1 ? "Mode 3":"None"); + printk(KERN_INFO "ide-tape: Minimum Multi-word DMA cycle per word: "); + if (id->eide_dma_min == 0) + printk("Not supported\n"); + else + printk("%d ns\n",id->eide_dma_min); + + printk(KERN_INFO "ide-tape: Manufacturer\'s Recommended Multi-word cycle: "); + if (id->eide_dma_time == 0) + printk("Not supported\n"); + else + printk("%d ns\n",id->eide_dma_time); + + printk(KERN_INFO "ide-tape: Minimum PIO cycle without IORDY: "); + if (id->eide_pio == 0) + printk("Not supported\n"); + else + printk("%d ns\n",id->eide_pio); + + printk(KERN_INFO "ide-tape: Minimum PIO cycle with IORDY: "); + if (id->eide_pio_iordy == 0) + printk("Not supported\n"); + else + printk("%d ns\n",id->eide_pio_iordy); + + } else + printk(KERN_INFO "ide-tape: According to the device, fields 64-70 are not valid.\n"); +#endif /* IDETAPE_DEBUG_INFO */ + + /* Check that we can support this device */ + + if (gcw.protocol !=2 ) + printk(KERN_ERR "ide-tape: Protocol is not ATAPI\n"); + else if (gcw.device_type != 1) + printk(KERN_ERR "ide-tape: Device type is not set to tape\n"); + else if (!gcw.removable) + printk(KERN_ERR "ide-tape: The removable flag is not set\n"); + else if (gcw.packet_size != 0) { + printk(KERN_ERR "ide-tape: Packet size is not 12 bytes long\n"); + if (gcw.packet_size == 1) + printk(KERN_ERR "ide-tape: Sorry, padding to 16 bytes is still not supported\n"); + } else + return 1; + return 0; +} + +/* + * Use INQUIRY to get the firmware revision + */ +static void idetape_get_inquiry_results (ide_drive_t *drive) +{ + char *r; + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + idetape_inquiry_result_t *inquiry; + + idetape_create_inquiry_cmd(&pc); + if (idetape_queue_pc_tail(drive, &pc)) { + printk(KERN_ERR "ide-tape: %s: can't get INQUIRY results\n", tape->name); + return; + } + inquiry = (idetape_inquiry_result_t *) pc.buffer; + memcpy(tape->vendor_id, inquiry->vendor_id, 8); + memcpy(tape->product_id, inquiry->product_id, 16); + memcpy(tape->firmware_revision, inquiry->revision_level, 4); + ide_fixstring(tape->vendor_id, 10, 0); + ide_fixstring(tape->product_id, 18, 0); + ide_fixstring(tape->firmware_revision, 6, 0); + r = tape->firmware_revision; + if (*(r + 1) == '.') + tape->firmware_revision_num = (*r - '0') * 100 + (*(r + 2) - '0') * 10 + *(r + 3) - '0'; + printk(KERN_INFO "ide-tape: %s <-> %s: %s %s rev %s\n", drive->name, tape->name, tape->vendor_id, tape->product_id, tape->firmware_revision); +} + +/* + * idetape_get_mode_sense_results asks the tape about its various + * parameters. In particular, we will adjust our data transfer buffer + * size to the recommended value as returned by the tape. + */ +static void idetape_get_mode_sense_results (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + idetape_mode_parameter_header_t *header; + idetape_capabilities_page_t *capabilities; + + idetape_create_mode_sense_cmd(&pc, IDETAPE_CAPABILITIES_PAGE); + if (idetape_queue_pc_tail(drive, &pc)) { + printk(KERN_ERR "ide-tape: Can't get tape parameters - assuming some default values\n"); + tape->tape_block_size = 512; + tape->capabilities.ctl = 52; + tape->capabilities.speed = 450; + tape->capabilities.buffer_size = 6 * 52; + return; + } + header = (idetape_mode_parameter_header_t *) pc.buffer; + capabilities = (idetape_capabilities_page_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t) + header->bdl); + + capabilities->max_speed = ntohs(capabilities->max_speed); + capabilities->ctl = ntohs(capabilities->ctl); + capabilities->speed = ntohs(capabilities->speed); + capabilities->buffer_size = ntohs(capabilities->buffer_size); + + if (!capabilities->speed) { + printk(KERN_INFO "ide-tape: %s: overriding capabilities->speed (assuming 650KB/sec)\n", drive->name); + capabilities->speed = 650; + } + if (!capabilities->max_speed) { + printk(KERN_INFO "ide-tape: %s: overriding capabilities->max_speed (assuming 650KB/sec)\n", drive->name); + capabilities->max_speed = 650; + } + + tape->capabilities = *capabilities; /* Save us a copy */ + if (capabilities->blk512) + tape->tape_block_size = 512; + else if (capabilities->blk1024) + tape->tape_block_size = 1024; + +#if IDETAPE_DEBUG_INFO + printk(KERN_INFO "ide-tape: Dumping the results of the MODE SENSE packet command\n"); + printk(KERN_INFO "ide-tape: Mode Parameter Header:\n"); + printk(KERN_INFO "ide-tape: Mode Data Length - %d\n",header->mode_data_length); + printk(KERN_INFO "ide-tape: Medium Type - %d\n",header->medium_type); + printk(KERN_INFO "ide-tape: Device Specific Parameter - %d\n",header->dsp); + printk(KERN_INFO "ide-tape: Block Descriptor Length - %d\n",header->bdl); + + printk(KERN_INFO "ide-tape: Capabilities and Mechanical Status Page:\n"); + printk(KERN_INFO "ide-tape: Page code - %d\n",capabilities->page_code); + printk(KERN_INFO "ide-tape: Page length - %d\n",capabilities->page_length); + printk(KERN_INFO "ide-tape: Read only - %s\n",capabilities->ro ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports reverse space - %s\n",capabilities->sprev ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports erase initiated formatting - %s\n",capabilities->efmt ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports QFA two Partition format - %s\n",capabilities->qfa ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports locking the medium - %s\n",capabilities->lock ? "Yes":"No"); + printk(KERN_INFO "ide-tape: The volume is currently locked - %s\n",capabilities->locked ? "Yes":"No"); + printk(KERN_INFO "ide-tape: The device defaults in the prevent state - %s\n",capabilities->prevent ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports ejecting the medium - %s\n",capabilities->eject ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports error correction - %s\n",capabilities->ecc ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports data compression - %s\n",capabilities->cmprs ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports 512 bytes block size - %s\n",capabilities->blk512 ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports 1024 bytes block size - %s\n",capabilities->blk1024 ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Supports 32768 bytes block size / Restricted byte count for PIO transfers - %s\n",capabilities->blk32768 ? "Yes":"No"); + printk(KERN_INFO "ide-tape: Maximum supported speed in KBps - %d\n",capabilities->max_speed); + printk(KERN_INFO "ide-tape: Continuous transfer limits in blocks - %d\n",capabilities->ctl); + printk(KERN_INFO "ide-tape: Current speed in KBps - %d\n",capabilities->speed); + printk(KERN_INFO "ide-tape: Buffer size - %d\n",capabilities->buffer_size*512); +#endif /* IDETAPE_DEBUG_INFO */ +} + +/* + * ide_get_blocksize_from_block_descriptor does a mode sense page 0 with block descriptor + * and if it succeeds sets the tape block size with the reported value + */ +static void idetape_get_blocksize_from_block_descriptor(ide_drive_t *drive) +{ + + idetape_tape_t *tape = drive->driver_data; + idetape_pc_t pc; + idetape_mode_parameter_header_t *header; + idetape_parameter_block_descriptor_t *block_descrp; + + idetape_create_mode_sense_cmd(&pc, IDETAPE_BLOCK_DESCRIPTOR); + if (idetape_queue_pc_tail(drive, &pc)) { + printk(KERN_ERR "ide-tape: Can't get block descriptor\n"); + if (tape->tape_block_size == 0) { + printk(KERN_WARNING "ide-tape: Cannot deal with zero block size, assume 32k\n"); + tape->tape_block_size = 32768; + } + return; + } + header = (idetape_mode_parameter_header_t *) pc.buffer; + block_descrp = (idetape_parameter_block_descriptor_t *) (pc.buffer + sizeof(idetape_mode_parameter_header_t)); + tape->tape_block_size =( block_descrp->length[0]<<16) + (block_descrp->length[1]<<8) + block_descrp->length[2]; + tape->drv_write_prot = (header->dsp & 0x80) >> 7; + +#if IDETAPE_DEBUG_INFO + printk(KERN_INFO "ide-tape: Adjusted block size - %d\n", tape->tape_block_size); +#endif /* IDETAPE_DEBUG_INFO */ +} +static void idetape_add_settings (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + +/* + * drive setting name read/write ioctl ioctl data type min max mul_factor div_factor data pointer set function + */ + ide_add_setting(drive, "buffer", SETTING_READ, -1, -1, TYPE_SHORT, 0, 0xffff, 1, 2, &tape->capabilities.buffer_size, NULL); + ide_add_setting(drive, "pipeline_min", SETTING_RW, -1, -1, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->min_pipeline, NULL); + ide_add_setting(drive, "pipeline", SETTING_RW, -1, -1, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_stages, NULL); + ide_add_setting(drive, "pipeline_max", SETTING_RW, -1, -1, TYPE_INT, 1, 0xffff, tape->stage_size / 1024, 1, &tape->max_pipeline, NULL); + ide_add_setting(drive, "pipeline_used",SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_stages, NULL); + ide_add_setting(drive, "pipeline_pending",SETTING_READ,-1, -1, TYPE_INT, 0, 0xffff, tape->stage_size / 1024, 1, &tape->nr_pending_stages, NULL); + ide_add_setting(drive, "speed", SETTING_READ, -1, -1, TYPE_SHORT, 0, 0xffff, 1, 1, &tape->capabilities.speed, NULL); + ide_add_setting(drive, "stage", SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1024, &tape->stage_size, NULL); + ide_add_setting(drive, "tdsc", SETTING_RW, -1, -1, TYPE_INT, IDETAPE_DSC_RW_MIN, IDETAPE_DSC_RW_MAX, 1000, HZ, &tape->best_dsc_rw_frequency, NULL); + ide_add_setting(drive, "dsc_overlap", SETTING_RW, -1, -1, TYPE_BYTE, 0, 1, 1, 1, &drive->dsc_overlap, NULL); + ide_add_setting(drive, "pipeline_head_speed_c",SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->controlled_pipeline_head_speed, NULL); + ide_add_setting(drive, "pipeline_head_speed_u",SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->uncontrolled_pipeline_head_speed, NULL); + ide_add_setting(drive, "avg_speed", SETTING_READ, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->avg_speed, NULL); + ide_add_setting(drive, "debug_level",SETTING_RW, -1, -1, TYPE_INT, 0, 0xffff, 1, 1, &tape->debug_level, NULL); +} + +/* + * ide_setup is called to: + * + * 1. Initialize our various state variables. + * 2. Ask the tape for its capabilities. + * 3. Allocate a buffer which will be used for data + * transfer. The buffer size is chosen based on + * the recommendation which we received in step (2). + * + * Note that at this point ide.c already assigned us an irq, so that + * we can queue requests here and wait for their completion. + */ +static void idetape_setup (ide_drive_t *drive, idetape_tape_t *tape, int minor) +{ + unsigned long t1, tmid, tn, t; + int speed; + struct idetape_id_gcw gcw; + int stage_size; + struct sysinfo si; + + spin_lock_init(&tape->spinlock); + drive->dsc_overlap = 1; +#ifdef CONFIG_BLK_DEV_IDEPCI + if (HWIF(drive)->pci_dev != NULL) { + /* + * These two ide-pci host adapters appear to need DSC overlap disabled. + * This probably needs further analysis. + */ + if ((HWIF(drive)->pci_dev->device == PCI_DEVICE_ID_ARTOP_ATP850UF) || + (HWIF(drive)->pci_dev->device == PCI_DEVICE_ID_TTI_HPT343)) { + printk(KERN_INFO "ide-tape: %s: disabling DSC overlap\n", tape->name); + drive->dsc_overlap = 0; + } + } +#endif /* CONFIG_BLK_DEV_IDEPCI */ + /* Seagate Travan drives do not support DSC overlap. */ + if (strstr(drive->id->model, "Seagate STT3401")) + drive->dsc_overlap = 0; + tape->minor = minor; + tape->name[0] = 'h'; + tape->name[1] = 't'; + tape->name[2] = '0' + minor; + tape->chrdev_direction = idetape_direction_none; + tape->pc = tape->pc_stack; + tape->max_insert_speed = 10000; + tape->speed_control = 1; + *((unsigned short *) &gcw) = drive->id->config; + if (gcw.drq_type == 1) + set_bit(IDETAPE_DRQ_INTERRUPT, &tape->flags); + + tape->min_pipeline = tape->max_pipeline = tape->max_stages = 10; + + idetape_get_inquiry_results(drive); + idetape_get_mode_sense_results(drive); + idetape_get_blocksize_from_block_descriptor(drive); + tape->user_bs_factor = 1; + tape->stage_size = tape->capabilities.ctl * tape->tape_block_size; + while (tape->stage_size > 0xffff) { + printk(KERN_NOTICE "ide-tape: decreasing stage size\n"); + tape->capabilities.ctl /= 2; + tape->stage_size = tape->capabilities.ctl * tape->tape_block_size; + } + stage_size = tape->stage_size; + tape->pages_per_stage = stage_size / PAGE_SIZE; + if (stage_size % PAGE_SIZE) { + tape->pages_per_stage++; + tape->excess_bh_size = PAGE_SIZE - stage_size % PAGE_SIZE; + } + + /* + * Select the "best" DSC read/write polling frequency + * and pipeline size. + */ + speed = max(tape->capabilities.speed, tape->capabilities.max_speed); + + tape->max_stages = speed * 1000 * 10 / tape->stage_size; + + /* + * Limit memory use for pipeline to 10% of physical memory + */ + si_meminfo(&si); + if (tape->max_stages * tape->stage_size > si.totalram * si.mem_unit / 10) + tape->max_stages = si.totalram * si.mem_unit / (10 * tape->stage_size); + tape->max_stages = min(tape->max_stages, IDETAPE_MAX_PIPELINE_STAGES); + tape->min_pipeline = min(tape->max_stages, IDETAPE_MIN_PIPELINE_STAGES); + tape->max_pipeline = min(tape->max_stages * 2, IDETAPE_MAX_PIPELINE_STAGES); + if (tape->max_stages == 0) + tape->max_stages = tape->min_pipeline = tape->max_pipeline = 1; + + t1 = (tape->stage_size * HZ) / (speed * 1000); + tmid = (tape->capabilities.buffer_size * 32 * HZ) / (speed * 125); + tn = (IDETAPE_FIFO_THRESHOLD * tape->stage_size * HZ) / (speed * 1000); + + if (tape->max_stages) + t = tn; + else + t = t1; + + /* + * Ensure that the number we got makes sense; limit + * it within IDETAPE_DSC_RW_MIN and IDETAPE_DSC_RW_MAX. + */ + tape->best_dsc_rw_frequency = max_t(unsigned long, min_t(unsigned long, t, IDETAPE_DSC_RW_MAX), IDETAPE_DSC_RW_MIN); + printk(KERN_INFO "ide-tape: %s <-> %s: %dKBps, %d*%dkB buffer, " + "%dkB pipeline, %lums tDSC%s\n", + drive->name, tape->name, tape->capabilities.speed, + (tape->capabilities.buffer_size * 512) / tape->stage_size, + tape->stage_size / 1024, + tape->max_stages * tape->stage_size / 1024, + tape->best_dsc_rw_frequency * 1000 / HZ, + drive->using_dma ? ", DMA":""); + + idetape_add_settings(drive); +} + +static int idetape_cleanup (ide_drive_t *drive) +{ + idetape_tape_t *tape = drive->driver_data; + unsigned long flags; + + spin_lock_irqsave(&ide_lock, flags); + if (test_bit(IDETAPE_BUSY, &tape->flags) || drive->usage || + tape->first_stage != NULL || tape->merge_stage_size) { + spin_unlock_irqrestore(&ide_lock, flags); + return 1; + } + + spin_unlock_irqrestore(&ide_lock, flags); + DRIVER(drive)->busy = 0; + (void) ide_unregister_subdriver(drive); + + ide_unregister_region(tape->disk); + + ide_tape_put(tape); + + return 0; +} + +static void ide_tape_release(struct kref *kref) +{ + struct ide_tape_obj *tape = to_ide_tape(kref); + ide_drive_t *drive = tape->drive; + struct gendisk *g = tape->disk; + + drive->dsc_overlap = 0; + drive->driver_data = NULL; + devfs_remove("%s/mt", drive->devfs_name); + devfs_remove("%s/mtn", drive->devfs_name); + devfs_unregister_tape(g->number); + idetape_devs[tape->minor] = NULL; + g->private_data = NULL; + put_disk(g); + kfree(tape); +} + +#ifdef CONFIG_PROC_FS + +static int proc_idetape_read_name + (char *page, char **start, off_t off, int count, int *eof, void *data) +{ + ide_drive_t *drive = (ide_drive_t *) data; + idetape_tape_t *tape = drive->driver_data; + char *out = page; + int len; + + len = sprintf(out, "%s\n", tape->name); + PROC_IDE_READ_RETURN(page, start, off, count, eof, len); +} + +static ide_proc_entry_t idetape_proc[] = { + { "capacity", S_IFREG|S_IRUGO, proc_ide_read_capacity, NULL }, + { "name", S_IFREG|S_IRUGO, proc_idetape_read_name, NULL }, + { NULL, 0, NULL, NULL } +}; + +#else + +#define idetape_proc NULL + +#endif + +static int idetape_attach(ide_drive_t *drive); + +/* + * IDE subdriver functions, registered with ide.c + */ +static ide_driver_t idetape_driver = { + .owner = THIS_MODULE, + .name = "ide-tape", + .version = IDETAPE_VERSION, + .media = ide_tape, + .busy = 1, + .supports_dsc_overlap = 1, + .cleanup = idetape_cleanup, + .do_request = idetape_do_request, + .end_request = idetape_end_request, + .error = __ide_error, + .abort = __ide_abort, + .proc = idetape_proc, + .attach = idetape_attach, + .drives = LIST_HEAD_INIT(idetape_driver.drives), +}; + +/* + * Our character device supporting functions, passed to register_chrdev. + */ +static struct file_operations idetape_fops = { + .owner = THIS_MODULE, + .read = idetape_chrdev_read, + .write = idetape_chrdev_write, + .ioctl = idetape_chrdev_ioctl, + .open = idetape_chrdev_open, + .release = idetape_chrdev_release, +}; + +static int idetape_open(struct inode *inode, struct file *filp) +{ + struct gendisk *disk = inode->i_bdev->bd_disk; + struct ide_tape_obj *tape; + ide_drive_t *drive; + + if (!(tape = ide_tape_get(disk))) + return -ENXIO; + + drive = tape->drive; + + drive->usage++; + + return 0; +} + +static int idetape_release(struct inode *inode, struct file *filp) +{ + struct gendisk *disk = inode->i_bdev->bd_disk; + struct ide_tape_obj *tape = ide_tape_g(disk); + ide_drive_t *drive = tape->drive; + + drive->usage--; + + ide_tape_put(tape); + + return 0; +} + +static int idetape_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct block_device *bdev = inode->i_bdev; + struct ide_tape_obj *tape = ide_tape_g(bdev->bd_disk); + ide_drive_t *drive = tape->drive; + int err = generic_ide_ioctl(drive, file, bdev, cmd, arg); + if (err == -EINVAL) + err = idetape_blkdev_ioctl(drive, cmd, arg); + return err; +} + +static struct block_device_operations idetape_block_ops = { + .owner = THIS_MODULE, + .open = idetape_open, + .release = idetape_release, + .ioctl = idetape_ioctl, +}; + +static int idetape_attach (ide_drive_t *drive) +{ + idetape_tape_t *tape; + struct gendisk *g; + int minor; + + if (!strstr("ide-tape", drive->driver_req)) + goto failed; + if (!drive->present) + goto failed; + if (drive->media != ide_tape) + goto failed; + if (!idetape_identify_device (drive)) { + printk(KERN_ERR "ide-tape: %s: not supported by this version of ide-tape\n", drive->name); + goto failed; + } + if (drive->scsi) { + printk("ide-tape: passing drive %s to ide-scsi emulation.\n", drive->name); + goto failed; + } + if (strstr(drive->id->model, "OnStream DI-")) { + printk(KERN_WARNING "ide-tape: Use drive %s with ide-scsi emulation and osst.\n", drive->name); + printk(KERN_WARNING "ide-tape: OnStream support will be removed soon from ide-tape!\n"); + } + tape = (idetape_tape_t *) kmalloc (sizeof (idetape_tape_t), GFP_KERNEL); + if (tape == NULL) { + printk(KERN_ERR "ide-tape: %s: Can't allocate a tape structure\n", drive->name); + goto failed; + } + + g = alloc_disk(1 << PARTN_BITS); + if (!g) + goto out_free_tape; + + ide_init_disk(g, drive); + + if (ide_register_subdriver(drive, &idetape_driver)) { + printk(KERN_ERR "ide-tape: %s: Failed to register the driver with ide.c\n", drive->name); + goto out_put_disk; + } + + memset(tape, 0, sizeof(*tape)); + + kref_init(&tape->kref); + + tape->drive = drive; + tape->driver = &idetape_driver; + tape->disk = g; + + g->private_data = &tape->driver; + + drive->driver_data = tape; + + down(&idetape_ref_sem); + for (minor = 0; idetape_devs[minor]; minor++) + ; + idetape_devs[minor] = tape; + up(&idetape_ref_sem); + + idetape_setup(drive, tape, minor); + + devfs_mk_cdev(MKDEV(HWIF(drive)->major, minor), + S_IFCHR | S_IRUGO | S_IWUGO, + "%s/mt", drive->devfs_name); + devfs_mk_cdev(MKDEV(HWIF(drive)->major, minor + 128), + S_IFCHR | S_IRUGO | S_IWUGO, + "%s/mtn", drive->devfs_name); + + g->number = devfs_register_tape(drive->devfs_name); + g->fops = &idetape_block_ops; + ide_register_region(g); + + return 0; +out_put_disk: + put_disk(g); +out_free_tape: + kfree(tape); +failed: + return 1; +} + +MODULE_DESCRIPTION("ATAPI Streaming TAPE Driver"); +MODULE_LICENSE("GPL"); + +static void __exit idetape_exit (void) +{ + ide_unregister_driver(&idetape_driver); + unregister_chrdev(IDETAPE_MAJOR, "ht"); +} + +/* + * idetape_init will register the driver for each tape. + */ +static int idetape_init (void) +{ + if (register_chrdev(IDETAPE_MAJOR, "ht", &idetape_fops)) { + printk(KERN_ERR "ide-tape: Failed to register character device interface\n"); + return -EBUSY; + } + ide_register_driver(&idetape_driver); + return 0; +} + +module_init(idetape_init); +module_exit(idetape_exit); +MODULE_ALIAS_CHARDEV_MAJOR(IDETAPE_MAJOR); |