| /* |
| * 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 |
| */ |
| |
| |
| #include <linux/types.h> |
| #include <linux/errno.h> |
| #include <linux/init.h> |
| #include <linux/spinlock.h> |
| #include <linux/slab.h> |
| #include <linux/kmsg_dump.h> |
| #include <asm/uaccess.h> |
| #include <asm/nvram.h> |
| #include <asm/rtas.h> |
| #include <asm/prom.h> |
| #include <asm/machdep.h> |
| |
| /* Max bytes to read/write in one go */ |
| #define NVRW_CNT 0x20 |
| |
| static unsigned int nvram_size; |
| static int nvram_fetch, nvram_store; |
| static char nvram_buf[NVRW_CNT]; /* assume this is in the first 4GB */ |
| static DEFINE_SPINLOCK(nvram_lock); |
| |
| struct err_log_info { |
| int error_type; |
| unsigned int seq_num; |
| }; |
| |
| struct nvram_os_partition { |
| const char *name; |
| int req_size; /* desired size, in bytes */ |
| int min_size; /* minimum acceptable size (0 means req_size) */ |
| long size; /* size of data portion (excluding err_log_info) */ |
| long index; /* offset of data portion of partition */ |
| }; |
| |
| static struct nvram_os_partition rtas_log_partition = { |
| .name = "ibm,rtas-log", |
| .req_size = 2079, |
| .min_size = 1055, |
| .index = -1 |
| }; |
| |
| static struct nvram_os_partition oops_log_partition = { |
| .name = "lnx,oops-log", |
| .req_size = 4000, |
| .min_size = 2000, |
| .index = -1 |
| }; |
| |
| static const char *pseries_nvram_os_partitions[] = { |
| "ibm,rtas-log", |
| "lnx,oops-log", |
| NULL |
| }; |
| |
| static void oops_to_nvram(struct kmsg_dumper *dumper, |
| enum kmsg_dump_reason reason, |
| const char *old_msgs, unsigned long old_len, |
| const char *new_msgs, unsigned long new_len); |
| |
| static struct kmsg_dumper nvram_kmsg_dumper = { |
| .dump = oops_to_nvram |
| }; |
| |
| /* See clobbering_unread_rtas_event() */ |
| #define NVRAM_RTAS_READ_TIMEOUT 5 /* seconds */ |
| static unsigned long last_unread_rtas_event; /* timestamp */ |
| |
| /* We preallocate oops_buf during init to avoid kmalloc during oops/panic. */ |
| static char *oops_buf; |
| |
| static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index) |
| { |
| unsigned int i; |
| unsigned long len; |
| int done; |
| unsigned long flags; |
| char *p = buf; |
| |
| |
| if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE) |
| return -ENODEV; |
| |
| if (*index >= nvram_size) |
| return 0; |
| |
| i = *index; |
| if (i + count > nvram_size) |
| count = nvram_size - i; |
| |
| spin_lock_irqsave(&nvram_lock, flags); |
| |
| for (; count != 0; count -= len) { |
| len = count; |
| if (len > NVRW_CNT) |
| len = NVRW_CNT; |
| |
| if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf), |
| len) != 0) || len != done) { |
| spin_unlock_irqrestore(&nvram_lock, flags); |
| return -EIO; |
| } |
| |
| memcpy(p, nvram_buf, len); |
| |
| p += len; |
| i += len; |
| } |
| |
| spin_unlock_irqrestore(&nvram_lock, flags); |
| |
| *index = i; |
| return p - buf; |
| } |
| |
| static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index) |
| { |
| unsigned int i; |
| unsigned long len; |
| int done; |
| unsigned long flags; |
| const char *p = buf; |
| |
| if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE) |
| return -ENODEV; |
| |
| if (*index >= nvram_size) |
| return 0; |
| |
| i = *index; |
| if (i + count > nvram_size) |
| count = nvram_size - i; |
| |
| spin_lock_irqsave(&nvram_lock, flags); |
| |
| for (; count != 0; count -= len) { |
| len = count; |
| if (len > NVRW_CNT) |
| len = NVRW_CNT; |
| |
| memcpy(nvram_buf, p, len); |
| |
| if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf), |
| len) != 0) || len != done) { |
| spin_unlock_irqrestore(&nvram_lock, flags); |
| return -EIO; |
| } |
| |
| p += len; |
| i += len; |
| } |
| spin_unlock_irqrestore(&nvram_lock, flags); |
| |
| *index = i; |
| return p - buf; |
| } |
| |
| static ssize_t pSeries_nvram_get_size(void) |
| { |
| return nvram_size ? nvram_size : -ENODEV; |
| } |
| |
| |
| /* nvram_write_os_partition, 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 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_os_partition(struct nvram_os_partition *part, 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 (part->index == -1) { |
| return -ESPIPE; |
| } |
| |
| if (length > part->size) { |
| length = part->size; |
| } |
| |
| info.error_type = err_type; |
| info.seq_num = error_log_cnt; |
| |
| tmp_index = part->index; |
| |
| rc = ppc_md.nvram_write((char *)&info, sizeof(struct err_log_info), &tmp_index); |
| if (rc <= 0) { |
| pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, rc); |
| return rc; |
| } |
| |
| rc = ppc_md.nvram_write(buff, length, &tmp_index); |
| if (rc <= 0) { |
| pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, rc); |
| return rc; |
| } |
| |
| return 0; |
| } |
| |
| int nvram_write_error_log(char * buff, int length, |
| unsigned int err_type, unsigned int error_log_cnt) |
| { |
| int rc = nvram_write_os_partition(&rtas_log_partition, buff, length, |
| err_type, error_log_cnt); |
| if (!rc) |
| last_unread_rtas_event = get_seconds(); |
| return rc; |
| } |
| |
| /* 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 (rtas_log_partition.index == -1) |
| return -1; |
| |
| if (length > rtas_log_partition.size) |
| length = rtas_log_partition.size; |
| |
| tmp_index = rtas_log_partition.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; |
| |
| if (rtas_log_partition.index == -1) |
| return -1; |
| |
| tmp_index = rtas_log_partition.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; |
| } |
| last_unread_rtas_event = 0; |
| |
| return 0; |
| } |
| |
| /* pseries_nvram_init_os_partition |
| * |
| * This sets up a partition with an "OS" signature. |
| * |
| * The general strategy is the following: |
| * 1.) If a partition with the indicated name already exists... |
| * - If it's large enough, use it. |
| * - Otherwise, recycle it and keep going. |
| * 2.) Search for a free partition that is large enough. |
| * 3.) If there's not a free partition large enough, recycle any obsolete |
| * OS partitions and try again. |
| * 4.) Will first try getting a chunk that will satisfy the requested size. |
| * 5.) If a chunk of the requested size cannot be allocated, then try finding |
| * a chunk that will satisfy the minum needed. |
| * |
| * Returns 0 on success, else -1. |
| */ |
| static int __init pseries_nvram_init_os_partition(struct nvram_os_partition |
| *part) |
| { |
| loff_t p; |
| int size; |
| |
| /* Scan nvram for partitions */ |
| nvram_scan_partitions(); |
| |
| /* Look for ours */ |
| p = nvram_find_partition(part->name, NVRAM_SIG_OS, &size); |
| |
| /* Found one but too small, remove it */ |
| if (p && size < part->min_size) { |
| pr_info("nvram: Found too small %s partition," |
| " removing it...\n", part->name); |
| nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL); |
| p = 0; |
| } |
| |
| /* Create one if we didn't find */ |
| if (!p) { |
| p = nvram_create_partition(part->name, NVRAM_SIG_OS, |
| part->req_size, part->min_size); |
| if (p == -ENOSPC) { |
| pr_info("nvram: No room to create %s partition, " |
| "deleting any obsolete OS partitions...\n", |
| part->name); |
| nvram_remove_partition(NULL, NVRAM_SIG_OS, |
| pseries_nvram_os_partitions); |
| p = nvram_create_partition(part->name, NVRAM_SIG_OS, |
| part->req_size, part->min_size); |
| } |
| } |
| |
| if (p <= 0) { |
| pr_err("nvram: Failed to find or create %s" |
| " partition, err %d\n", part->name, (int)p); |
| return -1; |
| } |
| |
| part->index = p; |
| part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info); |
| |
| return 0; |
| } |
| |
| static void __init nvram_init_oops_partition(int rtas_partition_exists) |
| { |
| int rc; |
| |
| rc = pseries_nvram_init_os_partition(&oops_log_partition); |
| if (rc != 0) { |
| if (!rtas_partition_exists) |
| return; |
| pr_notice("nvram: Using %s partition to log both" |
| " RTAS errors and oops/panic reports\n", |
| rtas_log_partition.name); |
| memcpy(&oops_log_partition, &rtas_log_partition, |
| sizeof(rtas_log_partition)); |
| } |
| oops_buf = kmalloc(oops_log_partition.size, GFP_KERNEL); |
| rc = kmsg_dump_register(&nvram_kmsg_dumper); |
| if (rc != 0) { |
| pr_err("nvram: kmsg_dump_register() failed; returned %d\n", rc); |
| kfree(oops_buf); |
| return; |
| } |
| } |
| |
| static int __init pseries_nvram_init_log_partitions(void) |
| { |
| int rc; |
| |
| rc = pseries_nvram_init_os_partition(&rtas_log_partition); |
| nvram_init_oops_partition(rc == 0); |
| return 0; |
| } |
| machine_arch_initcall(pseries, pseries_nvram_init_log_partitions); |
| |
| int __init pSeries_nvram_init(void) |
| { |
| struct device_node *nvram; |
| const unsigned int *nbytes_p; |
| unsigned int proplen; |
| |
| nvram = of_find_node_by_type(NULL, "nvram"); |
| if (nvram == NULL) |
| return -ENODEV; |
| |
| nbytes_p = of_get_property(nvram, "#bytes", &proplen); |
| if (nbytes_p == NULL || proplen != sizeof(unsigned int)) { |
| of_node_put(nvram); |
| return -EIO; |
| } |
| |
| nvram_size = *nbytes_p; |
| |
| nvram_fetch = rtas_token("nvram-fetch"); |
| nvram_store = rtas_token("nvram-store"); |
| printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size); |
| of_node_put(nvram); |
| |
| ppc_md.nvram_read = pSeries_nvram_read; |
| ppc_md.nvram_write = pSeries_nvram_write; |
| ppc_md.nvram_size = pSeries_nvram_get_size; |
| |
| return 0; |
| } |
| |
| /* |
| * Try to capture the last capture_len bytes of the printk buffer. Return |
| * the amount actually captured. |
| */ |
| static size_t capture_last_msgs(const char *old_msgs, size_t old_len, |
| const char *new_msgs, size_t new_len, |
| char *captured, size_t capture_len) |
| { |
| if (new_len >= capture_len) { |
| memcpy(captured, new_msgs + (new_len - capture_len), |
| capture_len); |
| return capture_len; |
| } else { |
| /* Grab the end of old_msgs. */ |
| size_t old_tail_len = min(old_len, capture_len - new_len); |
| memcpy(captured, old_msgs + (old_len - old_tail_len), |
| old_tail_len); |
| memcpy(captured + old_tail_len, new_msgs, new_len); |
| return old_tail_len + new_len; |
| } |
| } |
| |
| /* |
| * Are we using the ibm,rtas-log for oops/panic reports? And if so, |
| * would logging this oops/panic overwrite an RTAS event that rtas_errd |
| * hasn't had a chance to read and process? Return 1 if so, else 0. |
| * |
| * We assume that if rtas_errd hasn't read the RTAS event in |
| * NVRAM_RTAS_READ_TIMEOUT seconds, it's probably not going to. |
| */ |
| static int clobbering_unread_rtas_event(void) |
| { |
| return (oops_log_partition.index == rtas_log_partition.index |
| && last_unread_rtas_event |
| && get_seconds() - last_unread_rtas_event <= |
| NVRAM_RTAS_READ_TIMEOUT); |
| } |
| |
| /* our kmsg_dump callback */ |
| static void oops_to_nvram(struct kmsg_dumper *dumper, |
| enum kmsg_dump_reason reason, |
| const char *old_msgs, unsigned long old_len, |
| const char *new_msgs, unsigned long new_len) |
| { |
| static unsigned int oops_count = 0; |
| size_t text_len; |
| |
| if (clobbering_unread_rtas_event()) |
| return; |
| |
| text_len = capture_last_msgs(old_msgs, old_len, new_msgs, new_len, |
| oops_buf, oops_log_partition.size); |
| (void) nvram_write_os_partition(&oops_log_partition, oops_buf, |
| (int) text_len, ERR_TYPE_KERNEL_PANIC, ++oops_count); |
| } |