#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)
{
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;
git.openpandora.org / pandora-kernel.git / blobdiff