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Diffstat (limited to 'arch/powerpc/platforms/pseries/nvram.c')
-rw-r--r--arch/powerpc/platforms/pseries/nvram.c255
1 files changed, 196 insertions, 59 deletions
diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index 7e828ba..419707b 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>
@@ -30,17 +32,54 @@ 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"
+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)
{
@@ -134,7 +173,7 @@ static ssize_t pSeries_nvram_get_size(void)
}
-/* nvram_write_error_log
+/* 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
@@ -156,48 +195,58 @@ static ssize_t pSeries_nvram_get_size(void)
* The 'data' section would look like (in bytes):
* +--------------+------------+-----------------------------------+
* | event_logged | sequence # | error log |
- * |0 3|4 7|8 nvram_error_log_size-1|
+ * |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_error_log(char * buff, int length,
- unsigned int err_type, unsigned int error_log_cnt)
+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 (nvram_error_log_index == -1) {
+ if (part->index == -1) {
return -ESPIPE;
}
- if (length > nvram_error_log_size) {
- length = nvram_error_log_size;
+ if (length > part->size) {
+ length = part->size;
}
info.error_type = err_type;
info.seq_num = error_log_cnt;
- tmp_index = nvram_error_log_index;
+ tmp_index = part->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);
+ pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, 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);
+ 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'
@@ -209,13 +258,13 @@ int nvram_read_error_log(char * buff, int length,
loff_t tmp_index;
struct err_log_info info;
- if (nvram_error_log_index == -1)
+ if (rtas_log_partition.index == -1)
return -1;
- if (length > nvram_error_log_size)
- length = nvram_error_log_size;
+ if (length > rtas_log_partition.size)
+ length = rtas_log_partition.size;
- tmp_index = nvram_error_log_index;
+ tmp_index = rtas_log_partition.index;
rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
if (rc <= 0) {
@@ -244,37 +293,40 @@ int nvram_clear_error_log(void)
int clear_word = ERR_FLAG_ALREADY_LOGGED;
int rc;
- if (nvram_error_log_index == -1)
+ if (rtas_log_partition.index == -1)
return -1;
- tmp_index = nvram_error_log_index;
+ 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_log_partition
+/* pseries_nvram_init_os_partition
*
- * This will setup the partition we need for buffering the
- * error logs and cleanup partitions if needed.
+ * This sets up a partition with an "OS" signature.
*
* 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).
+ * 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_log_partition(void)
+static int __init pseries_nvram_init_os_partition(struct nvram_os_partition
+ *part)
{
loff_t p;
int size;
@@ -282,47 +334,76 @@ static int __init pseries_nvram_init_log_partition(void)
/* Scan nvram for partitions */
nvram_scan_partitions();
- /* Lookg for ours */
- p = nvram_find_partition(NVRAM_LOG_PART_NAME, NVRAM_SIG_OS, &size);
+ /* Look for ours */
+ p = nvram_find_partition(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);
+ 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(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
- */
+ 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 "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);
+ 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 "NVRAM_LOG_PART_NAME
- " partition, err %d\n", (int)p);
- return 0;
+ pr_err("nvram: Failed to find or create %s"
+ " partition, err %d\n", part->name, (int)p);
+ return -1;
}
- nvram_error_log_index = p;
- nvram_error_log_size = nvram_get_partition_size(p) -
- sizeof(struct err_log_info);
+ part->index = p;
+ part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
return 0;
}
-machine_arch_initcall(pseries, pseries_nvram_init_log_partition);
+
+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)
{
@@ -353,3 +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);
+}
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