powerpc/pseries: Read of-config partition via pstore

This patch set exploits the pstore subsystem to read details of
of-config partition in NVRAM to a separate file in /dev/pstore.
For instance, of-config partition details will be stored in a
file named [of-nvram-5].

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>

diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index 714ed8a..f7392f6 100644 (file)
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -132,9 +132,16 @@ static size_t oops_data_sz;
 static struct z_stream_s stream;
 
 #ifdef CONFIG_PSTORE
+static struct nvram_os_partition of_config_partition = {
+       .name = "of-config",
+       .index = -1,
+       .os_partition = false
+};
+
 static enum pstore_type_id nvram_type_ids[] = {
        PSTORE_TYPE_DMESG,
        PSTORE_TYPE_PPC_RTAS,
+       PSTORE_TYPE_PPC_OF,
        -1
 };
 static int read_type;
@@ -332,10 +339,15 @@ int nvram_read_partition(struct nvram_os_partition *part, char *buff,
 
        tmp_index = part->index;
 
-       rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
-       if (rc <= 0) {
-               pr_err("%s: Failed nvram_read (%d)\n", __FUNCTION__, rc);
-               return rc;
+       if (part->os_partition) {
+               rc = ppc_md.nvram_read((char *)&info,
+                                       sizeof(struct err_log_info),
+                                       &tmp_index);
+               if (rc <= 0) {
+                       pr_err("%s: Failed nvram_read (%d)\n", __FUNCTION__,
+                                                                       rc);
+                       return rc;
+               }
        }
 
        rc = ppc_md.nvram_read(buff, length, &tmp_index);
@@ -344,8 +356,10 @@ int nvram_read_partition(struct nvram_os_partition *part, char *buff,
                return rc;
        }
 
-       *error_log_cnt = info.seq_num;
-       *err_type = info.error_type;
+       if (part->os_partition) {
+               *error_log_cnt = info.seq_num;
+               *err_type = info.error_type;
+       }
 
        return 0;
 }
@@ -516,7 +530,7 @@ static int nvram_pstore_write(enum pstore_type_id type,
 }
 
 /*
- * Reads the oops/panic report and ibm,rtas-log partition.
+ * Reads the oops/panic report, rtas and of-config partition.
  * Returns the length of the data we read from each partition.
  * Returns 0 if we've been called before.
  */
@@ -525,9 +539,11 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
                                struct pstore_info *psi)
 {
        struct oops_log_info *oops_hdr;
-       unsigned int err_type, id_no;
+       unsigned int err_type, id_no, size = 0;
        struct nvram_os_partition *part = NULL;
        char *buff = NULL;
+       int sig = 0;
+       loff_t p;
 
        read_type++;
 
@@ -542,10 +558,29 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
                time->tv_sec = last_rtas_event;
                time->tv_nsec = 0;
                break;
+       case PSTORE_TYPE_PPC_OF:
+               sig = NVRAM_SIG_OF;
+               part = &of_config_partition;
+               *type = PSTORE_TYPE_PPC_OF;
+               *id = PSTORE_TYPE_PPC_OF;
+               time->tv_sec = 0;
+               time->tv_nsec = 0;
+               break;
        default:
                return 0;
        }
 
+       if (!part->os_partition) {
+               p = nvram_find_partition(part->name, sig, &size);
+               if (p <= 0) {
+                       pr_err("nvram: Failed to find partition %s, "
+                               "err %d\n", part->name, (int)p);
+                       return 0;
+               }
+               part->index = p;
+               part->size = size;
+       }
+
        buff = kmalloc(part->size, GFP_KERNEL);
 
        if (!buff)
@@ -557,7 +592,9 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type,
        }
 
        *count = 0;
-       *id = id_no;
+
+       if (part->os_partition)
+               *id = id_no;
 
        if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) {
                oops_hdr = (struct oops_log_info *)buff;

diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index ec24f9c..73148ae 100644 (file)
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -327,6 +327,9 @@ int pstore_mkfile(enum pstore_type_id type, char *psname, u64 id, int count,
        case PSTORE_TYPE_PPC_RTAS:
                sprintf(name, "rtas-%s-%lld", psname, id);
                break;
+       case PSTORE_TYPE_PPC_OF:
+               sprintf(name, "powerpc-ofw-%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 d7a8fe9..615dc18 100644 (file)
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -37,6 +37,7 @@ enum pstore_type_id {
        PSTORE_TYPE_FTRACE      = 3,
        /* PPC64 partition types */
        PSTORE_TYPE_PPC_RTAS    = 4,
+       PSTORE_TYPE_PPC_OF      = 5,
        PSTORE_TYPE_UNKNOWN     = 255
 };