powerpc/pseries: Read common partition via pstore

This patch exploits pstore subsystem to read details of common partition
in NVRAM to a separate file in /dev/pstore. For instance, common partition
details will be stored in a file named [common-nvram-6].

Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 20 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index f7392f6ea7b3..14cc486709f6 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -138,10 +138,17 @@ static struct nvram_os_partition of_config_partition = {
         .os_partition = false
 };
 
+static struct nvram_os_partition common_partition = {
+        .name = "common",
+        .index = -1,
+        .os_partition = false
+};
+
 static enum pstore_type_id nvram_type_ids[] = {
         PSTORE_TYPE_DMESG,
         PSTORE_TYPE_PPC_RTAS,
         PSTORE_TYPE_PPC_OF,
+        PSTORE_TYPE_PPC_COMMON,
         -1
 };
 static int read_type;
@@ -530,7 +537,7 @@ static int nvram_pstore_write(enum pstore_type_id type,
 }
 
 /*
- * Reads the oops/panic report, rtas and of-config partition.
+ * Reads the oops/panic report, rtas, of-config and common partition.
  * Returns the length of the data we read from each partition.
  * Returns 0 if we've been called before.
  */
@@ -566,6 +573,14 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
                 time->tv_sec = 0;
                 time->tv_nsec = 0;
                 break;
+        case PSTORE_TYPE_PPC_COMMON:
+                sig = NVRAM_SIG_SYS;
+                part = &common_partition;
+                *type = PSTORE_TYPE_PPC_COMMON;
+                *id = PSTORE_TYPE_PPC_COMMON;
+                time->tv_sec = 0;
+                time->tv_nsec = 0;
+                break;
         default:
                 return 0;
         }
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 73148aef9e31..08c3d76b24ca 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -330,6 +330,9 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
         case PSTORE_TYPE_PPC_OF:
                 sprintf(name, "powerpc-ofw-%s-%lld", psname, id);
                 break;
+        case PSTORE_TYPE_PPC_COMMON:
+                sprintf(name, "powerpc-common-%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 615dc18638b8..656699fcc7d7 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -38,6 +38,7 @@ enum pstore_type_id {
         /* PPC64 partition types */
         PSTORE_TYPE_PPC_RTAS    = 4,
         PSTORE_TYPE_PPC_OF      = 5,
+        PSTORE_TYPE_PPC_COMMON  = 6,
         PSTORE_TYPE_UNKNOWN     = 255
 };