Re: [PATCH 5/8] Read rtas partition via pstore

[Aruna Balakrishnaiah]

On Monday 15 April 2013 01:31 PM, Michael Ellerman wrote:

On Wed, Apr 10, 2013 at 12:53:27PM +0530, Aruna Balakrishnaiah wrote:

This patch exploits pstore infrastructure to read the details
from NVRAM's rtas partition.

Does that mean it's exposed in the pstore filesystem?

Yeah thats right.

Signed-off-by: Aruna Balakrishnaiah <ar...@linux.vnet.ibm.com>
Reviewed-by: Jim Keniston <jkeni...@us.ibm.com>
---
  arch/powerpc/platforms/pseries/nvram.c |   33 +++++++++++++++++++++++++-------
  fs/pstore/inode.c                      |    3 +++
  include/linux/pstore.h                 |    2 ++
  3 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/nvram.c 
b/arch/powerpc/platforms/pseries/nvram.c
index 82d32a2..d420b1d 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -144,9 +144,11 @@ static size_t oops_data_sz;
  #ifdef CONFIG_PSTORE
  static enum pstore_type_id nvram_type_ids[] = {
        PSTORE_TYPE_DMESG,
+       PSTORE_TYPE_RTAS,
        -1
  };
  static int read_type;
+static unsigned long last_rtas_event;
  #endif
  /* Compression parameters */
  #define COMPR_LEVEL 6
@@ -315,8 +317,13 @@ int nvram_write_error_log(char * buff, int length,
  {
        int rc = nvram_write_os_partition(&rtas_log_partition, buff, length,
                                                err_type, error_log_cnt);
-       if (!rc)
+       if (!rc) {
                last_unread_rtas_event = get_seconds();
+#ifdef CONFIG_PSTORE
+               last_rtas_event = get_seconds();
+#endif
+       }
+
        return rc;
  }

@@ -745,7 +752,7 @@ static int nvram_pstore_write(enum pstore_type_id type,

  }

/*

- * Reads the oops/panic report.
+ * Reads the oops/panic report and ibm,rtas-log partition.
   * Returns the length of the data we read from each partition.
   * Returns 0 if we've been called before.
   */
@@ -765,6 +772,12 @@ static ssize_t nvram_pstore_read(u64 *id, enum 
pstore_type_id *type,
                part = &oops_log_partition;
                *type = PSTORE_TYPE_DMESG;
                break;
+       case PSTORE_TYPE_RTAS:
+               part = &rtas_log_partition;
+               *type = PSTORE_TYPE_RTAS;
+               time->tv_sec = last_rtas_event;
+               time->tv_nsec = 0;
+               break;
        default:
                return 0;
        }
@@ -781,11 +794,17 @@ static ssize_t nvram_pstore_read(u64 *id, enum 
pstore_type_id *type,

*count = 0;

        *id = id_no;
-       oops_hdr = (struct oops_log_info *)buff;
-       *buf = buff + sizeof(*oops_hdr);
-       time->tv_sec = oops_hdr->timestamp;
-       time->tv_nsec = 0;
-       return oops_hdr->report_length;
+
+       if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
+               oops_hdr = (struct oops_log_info *)buff;
+               *buf = buff + sizeof(*oops_hdr);
+               time->tv_sec = oops_hdr->timestamp;
+               time->tv_nsec = 0;
+               return oops_hdr->report_length;
+       }
+
+       *buf = buff;
+       return part->size;
  }
  #else
  static int nvram_pstore_open(struct pstore_info *psi)
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index e4bcb2c..59b1454 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -324,6 +324,9 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, 
u64 id, int count,
        case PSTORE_TYPE_MCE:
                sprintf(name, "mce-%s-%lld", psname, id);
                break;
+       case PSTORE_TYPE_RTAS:
+               sprintf(name, "rtas-%s-%lld", psname, id);
+               break;
        case PSTORE_TYPE_UNKNOWN:
                sprintf(name, "unknown-%s-%lld", psname, id);
                break;
diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 75d0176..4eb94c9 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -35,6 +35,8 @@ enum pstore_type_id {
        PSTORE_TYPE_MCE         = 1,
        PSTORE_TYPE_CONSOLE     = 2,
        PSTORE_TYPE_FTRACE      = 3,
+       /* PPC64 partition types */
+       PSTORE_TYPE_RTAS        = 10,
        PSTORE_TYPE_UNKNOWN     = 255

I think you should probably just continue at 4, and call it
PSTORE_TYPE_PPC_RTAS. But you must get an ACK from the pstore
maintainers for this and the previous hunk, and I don't see them on CC.

Sure, will add them on cc in my next version of the patches.

cheers

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