[PATCH 5/8] Read rtas partition via pstore

[Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>]

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

Signed-off-by: Aruna Balakrishnaiah <aruna@linux.vnet.ibm.com>
Reviewed-by: Jim Keniston <jkenisto@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
 };