From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- drivers/scsi/hosts.c | 462 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 462 insertions(+) create mode 100644 drivers/scsi/hosts.c (limited to 'drivers/scsi/hosts.c') diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c new file mode 100644 index 00000000000..ba347576d99 --- /dev/null +++ b/drivers/scsi/hosts.c @@ -0,0 +1,462 @@ +/* + * hosts.c Copyright (C) 1992 Drew Eckhardt + * Copyright (C) 1993, 1994, 1995 Eric Youngdale + * Copyright (C) 2002-2003 Christoph Hellwig + * + * mid to lowlevel SCSI driver interface + * Initial versions: Drew Eckhardt + * Subsequent revisions: Eric Youngdale + * + * + * + * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli + * Added QLOGIC QLA1280 SCSI controller kernel host support. + * August 4, 1999 Fred Lewis, Intel DuPont + * + * Updated to reflect the new initialization scheme for the higher + * level of scsi drivers (sd/sr/st) + * September 17, 2000 Torben Mathiasen + * + * Restructured scsi_host lists and associated functions. + * September 04, 2002 Mike Anderson (andmike@us.ibm.com) + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "scsi_priv.h" +#include "scsi_logging.h" + + +static int scsi_host_next_hn; /* host_no for next new host */ + + +static void scsi_host_cls_release(struct class_device *class_dev) +{ + put_device(&class_to_shost(class_dev)->shost_gendev); +} + +static struct class shost_class = { + .name = "scsi_host", + .release = scsi_host_cls_release, +}; + +/** + * scsi_host_cancel - cancel outstanding IO to this host + * @shost: pointer to struct Scsi_Host + * recovery: recovery requested to run. + **/ +void scsi_host_cancel(struct Scsi_Host *shost, int recovery) +{ + struct scsi_device *sdev; + + set_bit(SHOST_CANCEL, &shost->shost_state); + shost_for_each_device(sdev, shost) { + scsi_device_cancel(sdev, recovery); + } + wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY, + &shost->shost_state))); +} + +/** + * scsi_remove_host - remove a scsi host + * @shost: a pointer to a scsi host to remove + **/ +void scsi_remove_host(struct Scsi_Host *shost) +{ + scsi_forget_host(shost); + scsi_host_cancel(shost, 0); + scsi_proc_host_rm(shost); + + set_bit(SHOST_DEL, &shost->shost_state); + + transport_unregister_device(&shost->shost_gendev); + class_device_unregister(&shost->shost_classdev); + device_del(&shost->shost_gendev); +} +EXPORT_SYMBOL(scsi_remove_host); + +/** + * scsi_add_host - add a scsi host + * @shost: scsi host pointer to add + * @dev: a struct device of type scsi class + * + * Return value: + * 0 on success / != 0 for error + **/ +int scsi_add_host(struct Scsi_Host *shost, struct device *dev) +{ + struct scsi_host_template *sht = shost->hostt; + int error = -EINVAL; + + printk(KERN_INFO "scsi%d : %s\n", shost->host_no, + sht->info ? sht->info(shost) : sht->name); + + if (!shost->can_queue) { + printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", + sht->name); + goto out; + } + + if (!shost->shost_gendev.parent) + shost->shost_gendev.parent = dev ? dev : &platform_bus; + + error = device_add(&shost->shost_gendev); + if (error) + goto out; + + set_bit(SHOST_ADD, &shost->shost_state); + get_device(shost->shost_gendev.parent); + + error = class_device_add(&shost->shost_classdev); + if (error) + goto out_del_gendev; + + get_device(&shost->shost_gendev); + + if (shost->transportt->host_size && + (shost->shost_data = kmalloc(shost->transportt->host_size, + GFP_KERNEL)) == NULL) + goto out_del_classdev; + + if (shost->transportt->create_work_queue) { + snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d", + shost->host_no); + shost->work_q = create_singlethread_workqueue( + shost->work_q_name); + if (!shost->work_q) + goto out_free_shost_data; + } + + error = scsi_sysfs_add_host(shost); + if (error) + goto out_destroy_host; + + scsi_proc_host_add(shost); + return error; + + out_destroy_host: + if (shost->work_q) + destroy_workqueue(shost->work_q); + out_free_shost_data: + kfree(shost->shost_data); + out_del_classdev: + class_device_del(&shost->shost_classdev); + out_del_gendev: + device_del(&shost->shost_gendev); + out: + return error; +} +EXPORT_SYMBOL(scsi_add_host); + +static void scsi_host_dev_release(struct device *dev) +{ + struct Scsi_Host *shost = dev_to_shost(dev); + struct device *parent = dev->parent; + + if (shost->ehandler) { + DECLARE_COMPLETION(sem); + shost->eh_notify = &sem; + shost->eh_kill = 1; + up(shost->eh_wait); + wait_for_completion(&sem); + shost->eh_notify = NULL; + } + + if (shost->work_q) + destroy_workqueue(shost->work_q); + + scsi_proc_hostdir_rm(shost->hostt); + scsi_destroy_command_freelist(shost); + kfree(shost->shost_data); + + /* + * Some drivers (eg aha1542) do scsi_register()/scsi_unregister() + * during probing without performing a scsi_set_device() in between. + * In this case dev->parent is NULL. + */ + if (parent) + put_device(parent); + kfree(shost); +} + +/** + * scsi_host_alloc - register a scsi host adapter instance. + * @sht: pointer to scsi host template + * @privsize: extra bytes to allocate for driver + * + * Note: + * Allocate a new Scsi_Host and perform basic initialization. + * The host is not published to the scsi midlayer until scsi_add_host + * is called. + * + * Return value: + * Pointer to a new Scsi_Host + **/ +struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) +{ + struct Scsi_Host *shost; + int gfp_mask = GFP_KERNEL, rval; + DECLARE_COMPLETION(complete); + + if (sht->unchecked_isa_dma && privsize) + gfp_mask |= __GFP_DMA; + + /* Check to see if this host has any error handling facilities */ + if (!sht->eh_strategy_handler && !sht->eh_abort_handler && + !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler && + !sht->eh_host_reset_handler) { + printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n" + "ERROR: This is not a safe way to run your " + "SCSI host\n" + "ERROR: The error handling must be added to " + "this driver\n", sht->proc_name); + dump_stack(); + } + + shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); + if (!shost) + return NULL; + memset(shost, 0, sizeof(struct Scsi_Host) + privsize); + + spin_lock_init(&shost->default_lock); + scsi_assign_lock(shost, &shost->default_lock); + INIT_LIST_HEAD(&shost->__devices); + INIT_LIST_HEAD(&shost->__targets); + INIT_LIST_HEAD(&shost->eh_cmd_q); + INIT_LIST_HEAD(&shost->starved_list); + init_waitqueue_head(&shost->host_wait); + + init_MUTEX(&shost->scan_mutex); + + shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */ + shost->dma_channel = 0xff; + + /* These three are default values which can be overridden */ + shost->max_channel = 0; + shost->max_id = 8; + shost->max_lun = 8; + + /* Give each shost a default transportt */ + shost->transportt = &blank_transport_template; + + /* + * All drivers right now should be able to handle 12 byte + * commands. Every so often there are requests for 16 byte + * commands, but individual low-level drivers need to certify that + * they actually do something sensible with such commands. + */ + shost->max_cmd_len = 12; + shost->hostt = sht; + shost->this_id = sht->this_id; + shost->can_queue = sht->can_queue; + shost->sg_tablesize = sht->sg_tablesize; + shost->cmd_per_lun = sht->cmd_per_lun; + shost->unchecked_isa_dma = sht->unchecked_isa_dma; + shost->use_clustering = sht->use_clustering; + shost->ordered_flush = sht->ordered_flush; + shost->ordered_tag = sht->ordered_tag; + + /* + * hosts/devices that do queueing must support ordered tags + */ + if (shost->can_queue > 1 && shost->ordered_flush) { + printk(KERN_ERR "scsi: ordered flushes don't support queueing\n"); + shost->ordered_flush = 0; + } + + if (sht->max_host_blocked) + shost->max_host_blocked = sht->max_host_blocked; + else + shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; + + /* + * If the driver imposes no hard sector transfer limit, start at + * machine infinity initially. + */ + if (sht->max_sectors) + shost->max_sectors = sht->max_sectors; + else + shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; + + /* + * assume a 4GB boundary, if not set + */ + if (sht->dma_boundary) + shost->dma_boundary = sht->dma_boundary; + else + shost->dma_boundary = 0xffffffff; + + rval = scsi_setup_command_freelist(shost); + if (rval) + goto fail_kfree; + + device_initialize(&shost->shost_gendev); + snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", + shost->host_no); + shost->shost_gendev.release = scsi_host_dev_release; + + class_device_initialize(&shost->shost_classdev); + shost->shost_classdev.dev = &shost->shost_gendev; + shost->shost_classdev.class = &shost_class; + snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d", + shost->host_no); + + shost->eh_notify = &complete; + rval = kernel_thread(scsi_error_handler, shost, 0); + if (rval < 0) + goto fail_destroy_freelist; + wait_for_completion(&complete); + shost->eh_notify = NULL; + + scsi_proc_hostdir_add(shost->hostt); + return shost; + + fail_destroy_freelist: + scsi_destroy_command_freelist(shost); + fail_kfree: + kfree(shost); + return NULL; +} +EXPORT_SYMBOL(scsi_host_alloc); + +struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) +{ + struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); + + if (!sht->detect) { + printk(KERN_WARNING "scsi_register() called on new-style " + "template for driver %s\n", sht->name); + dump_stack(); + } + + if (shost) + list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); + return shost; +} +EXPORT_SYMBOL(scsi_register); + +void scsi_unregister(struct Scsi_Host *shost) +{ + list_del(&shost->sht_legacy_list); + scsi_host_put(shost); +} +EXPORT_SYMBOL(scsi_unregister); + +/** + * scsi_host_lookup - get a reference to a Scsi_Host by host no + * + * @hostnum: host number to locate + * + * Return value: + * A pointer to located Scsi_Host or NULL. + **/ +struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) +{ + struct class *class = &shost_class; + struct class_device *cdev; + struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p; + + down_read(&class->subsys.rwsem); + list_for_each_entry(cdev, &class->children, node) { + p = class_to_shost(cdev); + if (p->host_no == hostnum) { + shost = scsi_host_get(p); + break; + } + } + up_read(&class->subsys.rwsem); + + return shost; +} +EXPORT_SYMBOL(scsi_host_lookup); + +/** + * scsi_host_get - inc a Scsi_Host ref count + * @shost: Pointer to Scsi_Host to inc. + **/ +struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) +{ + if (test_bit(SHOST_DEL, &shost->shost_state) || + !get_device(&shost->shost_gendev)) + return NULL; + return shost; +} +EXPORT_SYMBOL(scsi_host_get); + +/** + * scsi_host_put - dec a Scsi_Host ref count + * @shost: Pointer to Scsi_Host to dec. + **/ +void scsi_host_put(struct Scsi_Host *shost) +{ + put_device(&shost->shost_gendev); +} +EXPORT_SYMBOL(scsi_host_put); + +int scsi_init_hosts(void) +{ + return class_register(&shost_class); +} + +void scsi_exit_hosts(void) +{ + class_unregister(&shost_class); +} + +int scsi_is_host_device(const struct device *dev) +{ + return dev->release == scsi_host_dev_release; +} +EXPORT_SYMBOL(scsi_is_host_device); + +/** + * scsi_queue_work - Queue work to the Scsi_Host workqueue. + * @shost: Pointer to Scsi_Host. + * @work: Work to queue for execution. + * + * Return value: + * 0 on success / != 0 for error + **/ +int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) +{ + if (unlikely(!shost->work_q)) { + printk(KERN_ERR + "ERROR: Scsi host '%s' attempted to queue scsi-work, " + "when no workqueue created.\n", shost->hostt->name); + dump_stack(); + + return -EINVAL; + } + + return queue_work(shost->work_q, work); +} +EXPORT_SYMBOL_GPL(scsi_queue_work); + +/** + * scsi_flush_work - Flush a Scsi_Host's workqueue. + * @shost: Pointer to Scsi_Host. + **/ +void scsi_flush_work(struct Scsi_Host *shost) +{ + if (!shost->work_q) { + printk(KERN_ERR + "ERROR: Scsi host '%s' attempted to flush scsi-work, " + "when no workqueue created.\n", shost->hostt->name); + dump_stack(); + return; + } + + flush_workqueue(shost->work_q); +} +EXPORT_SYMBOL_GPL(scsi_flush_work); 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