diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/platforms/pseries/nvram.c | 118 |
1 files changed, 115 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c index befb41bc4d3..419707b0724 100644 --- a/arch/powerpc/platforms/pseries/nvram.c +++ b/arch/powerpc/platforms/pseries/nvram.c @@ -16,6 +16,8 @@ #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> @@ -39,7 +41,7 @@ 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 of partition */ + long size; /* size of data portion (excluding err_log_info) */ long index; /* offset of data portion of partition */ }; @@ -50,11 +52,35 @@ static struct nvram_os_partition rtas_log_partition = { .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; @@ -214,8 +240,11 @@ int nvram_write_os_partition(struct nvram_os_partition *part, char * buff, int nvram_write_error_log(char * buff, int length, unsigned int err_type, unsigned int error_log_cnt) { - return nvram_write_os_partition(&rtas_log_partition, buff, length, + 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 @@ -274,6 +303,7 @@ int nvram_clear_error_log(void) printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc); return rc; } + last_unread_rtas_event = 0; return 0; } @@ -342,9 +372,35 @@ static int __init pseries_nvram_init_os_partition(struct nvram_os_partition 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) { - (void) pseries_nvram_init_os_partition(&rtas_log_partition); + 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); @@ -378,3 +434,59 @@ int __init pSeries_nvram_init(void) 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); +} |