diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/nvram.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/nvram.c | 205 |
1 files changed, 205 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c index bc3c7f2abd7..7e828ba29bc 100644 --- a/arch/powerpc/platforms/pseries/nvram.c +++ b/arch/powerpc/platforms/pseries/nvram.c @@ -22,11 +22,25 @@ #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); +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; +}; +#define NVRAM_MAX_REQ 2079 +#define NVRAM_MIN_REQ 1055 + +#define NVRAM_LOG_PART_NAME "ibm,rtas-log" static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index) { @@ -119,6 +133,197 @@ static ssize_t pSeries_nvram_get_size(void) return nvram_size ? nvram_size : -ENODEV; } + +/* 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; + + if (nvram_error_log_index == -1) + return -1; + + 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; +} + +/* pseries_nvram_init_log_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 log partition large enough then use it. + * 2.) If there is none 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 __init pseries_nvram_init_log_partition(void) +{ + loff_t p; + int size; + + /* Scan nvram for partitions */ + nvram_scan_partitions(); + + /* Lookg for ours */ + p = nvram_find_partition(NVRAM_LOG_PART_NAME, NVRAM_SIG_OS, &size); + + /* Found one but too small, remove it */ + if (p && size < NVRAM_MIN_REQ) { + pr_info("nvram: Found too small "NVRAM_LOG_PART_NAME" partition" + ",removing it..."); + nvram_remove_partition(NVRAM_LOG_PART_NAME, NVRAM_SIG_OS); + p = 0; + } + + /* Create one if we didn't find */ + if (!p) { + p = nvram_create_partition(NVRAM_LOG_PART_NAME, NVRAM_SIG_OS, + NVRAM_MAX_REQ, NVRAM_MIN_REQ); + /* No room for it, try to get rid of any OS partition + * and try again + */ + if (p == -ENOSPC) { + pr_info("nvram: No room to create "NVRAM_LOG_PART_NAME + " partition, deleting all OS partitions..."); + nvram_remove_partition(NULL, NVRAM_SIG_OS); + p = nvram_create_partition(NVRAM_LOG_PART_NAME, + NVRAM_SIG_OS, NVRAM_MAX_REQ, + NVRAM_MIN_REQ); + } + } + + if (p <= 0) { + pr_err("nvram: Failed to find or create "NVRAM_LOG_PART_NAME + " partition, err %d\n", (int)p); + return 0; + } + + nvram_error_log_index = p; + nvram_error_log_size = nvram_get_partition_size(p) - + sizeof(struct err_log_info); + + return 0; +} +machine_arch_initcall(pseries, pseries_nvram_init_log_partition); + int __init pSeries_nvram_init(void) { struct device_node *nvram; |