/* * c 2001 PPC 64 Team, IBM Corp * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. * * /dev/nvram driver for PPC64 * * This perhaps should live in drivers/char * * TODO: Split the /dev/nvram part (that one can use * drivers/char/generic_nvram.c) from the arch & partition * parsing code. */ #include <linux/module.h> #include <linux/types.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/miscdevice.h> #include <linux/fcntl.h> #include <linux/nvram.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <asm/uaccess.h> #include <asm/nvram.h> #include <asm/rtas.h> #include <asm/prom.h> #include <asm/machdep.h> #undef DEBUG_NVRAM static struct nvram_partition * nvram_part; static long nvram_error_log_index = -1; static long nvram_error_log_size = 0; struct err_log_info { int error_type; unsigned int seq_num; }; static loff_t dev_nvram_llseek(struct file *file, loff_t offset, int origin) { int size; if (ppc_md.nvram_size == NULL) return -ENODEV; size = ppc_md.nvram_size(); switch (origin) { case 1: offset += file->f_pos; break; case 2: offset += size; break; } if (offset < 0) return -EINVAL; file->f_pos = offset; return file->f_pos; } static ssize_t dev_nvram_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { ssize_t ret; char *tmp = NULL; ssize_t size; ret = -ENODEV; if (!ppc_md.nvram_size) goto out; ret = 0; size = ppc_md.nvram_size(); if (*ppos >= size || size < 0) goto out; count = min_t(size_t, count, size - *ppos); count = min(count, PAGE_SIZE); ret = -ENOMEM; tmp = kmalloc(count, GFP_KERNEL); if (!tmp) goto out; ret = ppc_md.nvram_read(tmp, count, ppos); if (ret <= 0) goto out; if (copy_to_user(buf, tmp, ret)) ret = -EFAULT; out: kfree(tmp); return ret; } static ssize_t dev_nvram_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { ssize_t ret; char *tmp = NULL; ssize_t size; ret = -ENODEV; if (!ppc_md.nvram_size) goto out; ret = 0; size = ppc_md.nvram_size(); if (*ppos >= size || size < 0) goto out; count = min_t(size_t, count, size - *ppos); count = min(count, PAGE_SIZE); ret = -ENOMEM; tmp = kmalloc(count, GFP_KERNEL); if (!tmp) goto out; ret = -EFAULT; if (copy_from_user(tmp, buf, count)) goto out; ret = ppc_md.nvram_write(tmp, count, ppos); out: kfree(tmp); return ret; } static int dev_nvram_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { switch(cmd) { #ifdef CONFIG_PPC_PMAC case OBSOLETE_PMAC_NVRAM_GET_OFFSET: printk(KERN_WARNING "nvram: Using obsolete PMAC_NVRAM_GET_OFFSET ioctl\n"); case IOC_NVRAM_GET_OFFSET: { int part, offset; if (!machine_is(powermac)) return -EINVAL; if (copy_from_user(&part, (void __user*)arg, sizeof(part)) != 0) return -EFAULT; if (part < pmac_nvram_OF || part > pmac_nvram_NR) return -EINVAL; offset = pmac_get_partition(part); if (offset < 0) return offset; if (copy_to_user((void __user*)arg, &offset, sizeof(offset)) != 0) return -EFAULT; return 0; } #endif /* CONFIG_PPC_PMAC */ default: return -EINVAL; } } const struct file_operations nvram_fops = { .owner = THIS_MODULE, .llseek = dev_nvram_llseek, .read = dev_nvram_read, .write = dev_nvram_write, .ioctl = dev_nvram_ioctl, }; static struct miscdevice nvram_dev = { NVRAM_MINOR, "nvram", &nvram_fops }; #ifdef DEBUG_NVRAM static void nvram_print_partitions(char * label) { struct list_head * p; struct nvram_partition * tmp_part; printk(KERN_WARNING "--------%s---------\n", label); printk(KERN_WARNING "indx\t\tsig\tchks\tlen\tname\n"); list_for_each(p, &nvram_part->partition) { tmp_part = list_entry(p, struct nvram_partition, partition); printk(KERN_WARNING "%4d \t%02x\t%02x\t%d\t%s\n", tmp_part->index, tmp_part->header.signature, tmp_part->header.checksum, tmp_part->header.length, tmp_part->header.name); } } #endif static int nvram_write_header(struct nvram_partition * part) { loff_t tmp_index; int rc; tmp_index = part->index; rc = ppc_md.nvram_write((char *)&part->header, NVRAM_HEADER_LEN, &tmp_index); return rc; } static unsigned char nvram_checksum(struct nvram_header *p) { unsigned int c_sum, c_sum2; unsigned short *sp = (unsigned short *)p->name; /* assume 6 shorts */ c_sum = p->signature + p->length + sp[0] + sp[1] + sp[2] + sp[3] + sp[4] + sp[5]; /* The sum may have spilled into the 3rd byte. Fold it back. */ c_sum = ((c_sum & 0xffff) + (c_sum >> 16)) & 0xffff; /* The sum cannot exceed 2 bytes. Fold it into a checksum */ c_sum2 = (c_sum >> 8) + (c_sum << 8); c_sum = ((c_sum + c_sum2) >> 8) & 0xff; return c_sum; } /* * Find an nvram partition, sig can be 0 for any * partition or name can be NULL for any name, else * tries to match both */ struct nvram_partition *nvram_find_partition(int sig, const char *name) { struct nvram_partition * part; struct list_head * p; list_for_each(p, &nvram_part->partition) { part = list_entry(p, struct nvram_partition, partition); if (sig && part->header.signature != sig) continue; if (name && 0 != strncmp(name, part->header.name, 12)) continue; return part; } return NULL; } EXPORT_SYMBOL(nvram_find_partition); static int nvram_remove_os_partition(void) { struct list_head *i; struct list_head *j; struct nvram_partition * part; struct nvram_partition * cur_part; int rc; list_for_each(i, &nvram_part->partition) { part = list_entry(i, struct nvram_partition, partition); if (part->header.signature != NVRAM_SIG_OS) continue; /* Make os partition a free partition */ part->header.signature = NVRAM_SIG_FREE; sprintf(part->header.name, "wwwwwwwwwwww"); part->header.checksum = nvram_checksum(&part->header); /* Merge contiguous free partitions backwards */ list_for_each_prev(j, &part->partition) { cur_part = list_entry(j, struct nvram_partition, partition); if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) { break; } part->header.length += cur_part->header.length; part->header.checksum = nvram_checksum(&part->header); part->index = cur_part->index; list_del(&cur_part->partition); kfree(cur_part); j = &part->partition; /* fixup our loop */ } /* Merge contiguous free partitions forwards */ list_for_each(j, &part->partition) { cur_part = list_entry(j, struct nvram_partition, partition); if (cur_part == nvram_part || cur_part->header.signature != NVRAM_SIG_FREE) { break; } part->header.length += cur_part->header.length; part->header.checksum = nvram_checksum(&part->header); list_del(&cur_part->partition); kfree(cur_part); j = &part->partition; /* fixup our loop */ } rc = nvram_write_header(part); if (rc <= 0) { printk(KERN_ERR "nvram_remove_os_partition: nvram_write failed (%d)\n", rc); return rc; } } return 0; } /* nvram_create_os_partition * * Create a OS linux partition to buffer error logs. * Will create a partition starting at the first free * space found if space has enough room. */ static int nvram_create_os_partition(void) { struct nvram_partition *part; struct nvram_partition *new_part; struct nvram_partition *free_part = NULL; int seq_init[2] = { 0, 0 }; loff_t tmp_index; long size = 0; int rc; /* Find a free partition that will give us the maximum needed size If can't find one that will give us the minimum size needed */ list_for_each_entry(part, &nvram_part->partition, partition) { if (part->header.signature != NVRAM_SIG_FREE) continue; if (part->header.length >= NVRAM_MAX_REQ) { size = NVRAM_MAX_REQ; free_part = part; break; } if (!size && part->header.length >= NVRAM_MIN_REQ) { size = NVRAM_MIN_REQ; free_part = part; } } if (!size) return -ENOSPC; /* Create our OS partition */ new_part = kmalloc(sizeof(*new_part), GFP_KERNEL); if (!new_part) { printk(KERN_ERR "nvram_create_os_partition: kmalloc failed\n"); return -ENOMEM; } new_part->index = free_part->index; new_part->header.signature = NVRAM_SIG_OS; new_part->header.length = size; strcpy(new_part->header.name, "ppc64,linux"); new_part->header.checksum = nvram_checksum(&new_part->header); rc = nvram_write_header(new_part); if (rc <= 0) { printk(KERN_ERR "nvram_create_os_partition: nvram_write_header \ failed (%d)\n", rc); return rc; } /* make sure and initialize to zero the sequence number and the error type logged */ tmp_index = new_part->index + NVRAM_HEADER_LEN; rc = ppc_md.nvram_write((char *)&seq_init, sizeof(seq_init), &tmp_index); if (rc <= 0) { printk(KERN_ERR "nvram_create_os_partition: nvram_write " "failed (%d)\n", rc); return rc; } nvram_error_log_index = new_part->index + NVRAM_HEADER_LEN; nvram_error_log_size = ((part->header.length - 1) * NVRAM_BLOCK_LEN) - sizeof(struct err_log_info); list_add_tail(&new_part->partition, &free_part->partition); if (free_part->header.length <= size) { list_del(&free_part->partition); kfree(free_part); return 0; } /* Adjust the partition we stole the space from */ free_part->index += size * NVRAM_BLOCK_LEN; free_part->header.length -= size; free_part->header.checksum = nvram_checksum(&free_part->header); rc = nvram_write_header(free_part); if (rc <= 0) { printk(KERN_ERR "nvram_create_os_partition: nvram_write_header " "failed (%d)\n", rc); return rc; } return 0; } /* nvram_setup_partition * * This will setup the partition we need for buffering the * error logs and cleanup partitions if needed. * * The general strategy is the following: * 1.) If there is ppc64,linux partition large enough then use it. * 2.) If there is not a ppc64,linux partition large enough, search * for a free partition that is large enough. * 3.) If there is not a free partition large enough remove * _all_ OS partitions and consolidate the space. * 4.) Will first try getting a chunk that will satisfy the maximum * error log size (NVRAM_MAX_REQ). * 5.) If the max chunk cannot be allocated then try finding a chunk * that will satisfy the minum needed (NVRAM_MIN_REQ). */ static int nvram_setup_partition(void) { struct list_head * p; struct nvram_partition * part; int rc; /* For now, we don't do any of this on pmac, until I * have figured out if it's worth killing some unused stuffs * in our nvram, as Apple defined partitions use pretty much * all of the space */ if (machine_is(powermac)) return -ENOSPC; /* see if we have an OS partition that meets our needs. will try getting the max we need. If not we'll delete partitions and try again. */ list_for_each(p, &nvram_part->partition) { part = list_entry(p, struct nvram_partition, partition); if (part->header.signature != NVRAM_SIG_OS) continue; if (strcmp(part->header.name, "ppc64,linux")) continue; if (part->header.length >= NVRAM_MIN_REQ) { /* found our partition */ nvram_error_log_index = part->index + NVRAM_HEADER_LEN; nvram_error_log_size = ((part->header.length - 1) * NVRAM_BLOCK_LEN) - sizeof(struct err_log_info); return 0; } } /* try creating a partition with the free space we have */ rc = nvram_create_os_partition(); if (!rc) { return 0; } /* need to free up some space */ rc = nvram_remove_os_partition(); if (rc) { return rc; } /* create a partition in this new space */ rc = nvram_create_os_partition(); if (rc) { printk(KERN_ERR "nvram_create_os_partition: Could not find a " "NVRAM partition large enough\n"); return rc; } return 0; } static int nvram_scan_partitions(void) { loff_t cur_index = 0; struct nvram_header phead; struct nvram_partition * tmp_part; unsigned char c_sum; char * header; int total_size; int err; if (ppc_md.nvram_size == NULL) return -ENODEV; total_size = ppc_md.nvram_size(); header = kmalloc(NVRAM_HEADER_LEN, GFP_KERNEL); if (!header) { printk(KERN_ERR "nvram_scan_partitions: Failed kmalloc\n"); return -ENOMEM; } while (cur_index < total_size) { err = ppc_md.nvram_read(header, NVRAM_HEADER_LEN, &cur_index); if (err != NVRAM_HEADER_LEN) { printk(KERN_ERR "nvram_scan_partitions: Error parsing " "nvram partitions\n"); goto out; } cur_index -= NVRAM_HEADER_LEN; /* nvram_read will advance us */ memcpy(&phead, header, NVRAM_HEADER_LEN); err = 0; c_sum = nvram_checksum(&phead); if (c_sum != phead.checksum) { printk(KERN_WARNING "WARNING: nvram partition checksum" " was %02x, should be %02x!\n", phead.checksum, c_sum); printk(KERN_WARNING "Terminating nvram partition scan\n"); goto out; } if (!phead.length) { printk(KERN_WARNING "WARNING: nvram corruption " "detected: 0-length partition\n"); goto out; } tmp_part = (struct nvram_partition *) kmalloc(sizeof(struct nvram_partition), GFP_KERNEL); err = -ENOMEM; if (!tmp_part) { printk(KERN_ERR "nvram_scan_partitions: kmalloc failed\n"); goto out; } memcpy(&tmp_part->header, &phead, NVRAM_HEADER_LEN); tmp_part->index = cur_index; list_add_tail(&tmp_part->partition, &nvram_part->partition); cur_index += phead.length * NVRAM_BLOCK_LEN; } err = 0; out: kfree(header); return err; } static int __init nvram_init(void) { int error; int rc; if (ppc_md.nvram_size == NULL || ppc_md.nvram_size() <= 0) return -ENODEV; rc = misc_register(&nvram_dev); if (rc != 0) { printk(KERN_ERR "nvram_init: failed to register device\n"); return rc; } /* initialize our anchor for the nvram partition list */ nvram_part = kmalloc(sizeof(struct nvram_partition), GFP_KERNEL); if (!nvram_part) { printk(KERN_ERR "nvram_init: Failed kmalloc\n"); return -ENOMEM; } INIT_LIST_HEAD(&nvram_part->partition); /* Get all the NVRAM partitions */ error = nvram_scan_partitions(); if (error) { printk(KERN_ERR "nvram_init: Failed nvram_scan_partitions\n"); return error; } if(nvram_setup_partition()) printk(KERN_WARNING "nvram_init: Could not find nvram partition" " for nvram buffered error logging.\n"); #ifdef DEBUG_NVRAM nvram_print_partitions("NVRAM Partitions"); #endif return rc; } void __exit nvram_cleanup(void) { misc_deregister( &nvram_dev ); } #ifdef CONFIG_PPC_PSERIES /* nvram_write_error_log * * We need to buffer the error logs into nvram to ensure that we have * the failure information to decode. If we have a severe error there * is no way to guarantee that the OS or the machine is in a state to * get back to user land and write the error to disk. For example if * the SCSI device driver causes a Machine Check by writing to a bad * IO address, there is no way of guaranteeing that the device driver * is in any state that is would also be able to write the error data * captured to disk, thus we buffer it in NVRAM for analysis on the * next boot. * * In NVRAM the partition containing the error log buffer will looks like: * Header (in bytes): * +-----------+----------+--------+------------+------------------+ * | signature | checksum | length | name | data | * |0 |1 |2 3|4 15|16 length-1| * +-----------+----------+--------+------------+------------------+ * * The 'data' section would look like (in bytes): * +--------------+------------+-----------------------------------+ * | event_logged | sequence # | error log | * |0 3|4 7|8 nvram_error_log_size-1| * +--------------+------------+-----------------------------------+ * * event_logged: 0 if event has not been logged to syslog, 1 if it has * sequence #: The unique sequence # for each event. (until it wraps) * error log: The error log from event_scan */ int nvram_write_error_log(char * buff, int length, unsigned int err_type, unsigned int error_log_cnt) { int rc; loff_t tmp_index; struct err_log_info info; if (nvram_error_log_index == -1) { return -ESPIPE; } if (length > nvram_error_log_size) { length = nvram_error_log_size; } info.error_type = err_type; info.seq_num = error_log_cnt; tmp_index = nvram_error_log_index; rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index); if (rc <= 0) { printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc); return rc; } rc = ppc_md.nvram_write(buff, length, &tmp_index); if (rc <= 0) { printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc); return rc; } return 0; } /* nvram_read_error_log * * Reads nvram for error log for at most 'length' */ int nvram_read_error_log(char * buff, int length, unsigned int * err_type, unsigned int * error_log_cnt) { int rc; loff_t tmp_index; struct err_log_info info; if (nvram_error_log_index == -1) return -1; if (length > nvram_error_log_size) length = nvram_error_log_size; tmp_index = nvram_error_log_index; rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index); if (rc <= 0) { printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); return rc; } rc = ppc_md.nvram_read(buff, length, &tmp_index); if (rc <= 0) { printk(KERN_ERR "nvram_read_error_log: Failed nvram_read (%d)\n", rc); return rc; } *error_log_cnt = info.seq_num; *err_type = info.error_type; return 0; } /* This doesn't actually zero anything, but it sets the event_logged * word to tell that this event is safely in syslog. */ int nvram_clear_error_log(void) { loff_t tmp_index; int clear_word = ERR_FLAG_ALREADY_LOGGED; int rc; tmp_index = nvram_error_log_index; rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index); if (rc <= 0) { printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc); return rc; } return 0; } #endif /* CONFIG_PPC_PSERIES */ module_init(nvram_init); module_exit(nvram_cleanup); MODULE_LICENSE("GPL");