powerpc/nvram: Generalize code for OS partitions in NVRAM

Adapt the functions used to create and write to the RTAS-log partition
to work with any OS-type partition.

Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 84 insertions, 59 deletions

diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index 7e828ba29bc..befb41bc4d3 100644
--- a/arch/powerpc/platforms/pseries/nvram.c
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -30,17 +30,30 @@ 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"
+struct nvram_os_partition {
+        const char *name;
+        int req_size;   /* desired size, in bytes */
+        int min_size;   /* minimum acceptable size (0 means req_size) */
+        long size;      /* size of data portion of partition */
+        long index;     /* offset of data portion of partition */
+};
+
+static struct nvram_os_partition rtas_log_partition = {
+        .name = "ibm,rtas-log",
+        .req_size = 2079,
+        .min_size = 1055,
+        .index = -1
+};
+
+static const char *pseries_nvram_os_partitions[] = {
+        "ibm,rtas-log",
+        NULL
+};
 
 static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
 {
@@ -134,7 +147,7 @@ static ssize_t pSeries_nvram_get_size(void)
 }
 
 
-/* nvram_write_error_log
+/* nvram_write_os_partition, 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
@@ -156,48 +169,55 @@ static ssize_t pSeries_nvram_get_size(void)
  * The 'data' section would look like (in bytes):
  * +--------------+------------+-----------------------------------+
  * | event_logged | sequence # | error log                         |
- * |0            3|4          7|8            nvram_error_log_size-1|
+ * |0            3|4          7|8                  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 nvram_write_os_partition(struct nvram_os_partition *part, 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) {
+        if (part->index == -1) {
                 return -ESPIPE;
         }
 
-        if (length > nvram_error_log_size) {
-                length = nvram_error_log_size;
+        if (length > part->size) {
+                length = part->size;
         }
 
         info.error_type = err_type;
         info.seq_num = error_log_cnt;
 
-        tmp_index = nvram_error_log_index;
+        tmp_index = part->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);
+                pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, 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);
+                pr_err("%s: Failed nvram_write (%d)\n", __FUNCTION__, rc);
                 return rc;
         }
         
         return 0;
 }
 
+int nvram_write_error_log(char * buff, int length,
+                          unsigned int err_type, unsigned int error_log_cnt)
+{
+        return nvram_write_os_partition(&rtas_log_partition, buff, length,
+                                                err_type, error_log_cnt);
+}
+
 /* nvram_read_error_log
  *
  * Reads nvram for error log for at most 'length'
@@ -209,13 +229,13 @@ int nvram_read_error_log(char * buff, int length,
         loff_t tmp_index;
         struct err_log_info info;
         
-        if (nvram_error_log_index == -1)
+        if (rtas_log_partition.index == -1)
                 return -1;
 
-        if (length > nvram_error_log_size)
-                length = nvram_error_log_size;
+        if (length > rtas_log_partition.size)
+                length = rtas_log_partition.size;
 
-        tmp_index = nvram_error_log_index;
+        tmp_index = rtas_log_partition.index;
 
         rc = ppc_md.nvram_read((char *)&info, sizeof(struct err_log_info), &tmp_index);
         if (rc <= 0) {
@@ -244,10 +264,10 @@ int nvram_clear_error_log(void)
         int clear_word = ERR_FLAG_ALREADY_LOGGED;
         int rc;
 
-        if (nvram_error_log_index == -1)
+        if (rtas_log_partition.index == -1)
                 return -1;
 
-        tmp_index = nvram_error_log_index;
+        tmp_index = rtas_log_partition.index;
         
         rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
         if (rc <= 0) {
@@ -258,23 +278,25 @@ int nvram_clear_error_log(void)
         return 0;
 }
 
-/* pseries_nvram_init_log_partition
+/* pseries_nvram_init_os_partition
  *
- * This will setup the partition we need for buffering the
- * error logs and cleanup partitions if needed.
+ * This sets up a partition with an "OS" signature.
  *
  * 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).
+ * 1.) If a partition with the indicated name already exists...
+ *      - If it's large enough, use it.
+ *      - Otherwise, recycle it and keep going.
+ * 2.) Search for a free partition that is large enough.
+ * 3.) If there's not a free partition large enough, recycle any obsolete
+ * OS partitions and try again.
+ * 4.) Will first try getting a chunk that will satisfy the requested size.
+ * 5.) If a chunk of the requested size cannot be allocated, then try finding
+ * a chunk that will satisfy the minum needed.
+ *
+ * Returns 0 on success, else -1.
  */
-static int __init pseries_nvram_init_log_partition(void)
+static int __init pseries_nvram_init_os_partition(struct nvram_os_partition
+                                                                        *part)
 {
         loff_t p;
         int size;
@@ -282,47 +304,50 @@ static int __init pseries_nvram_init_log_partition(void)
         /* Scan nvram for partitions */
         nvram_scan_partitions();
 
-        /* Lookg for ours */
-        p = nvram_find_partition(NVRAM_LOG_PART_NAME, NVRAM_SIG_OS, &size);
+        /* Look for ours */
+        p = nvram_find_partition(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);
+        if (p && size < part->min_size) {
+                pr_info("nvram: Found too small %s partition,"
+                                        " removing it...\n", part->name);
+                nvram_remove_partition(part->name, NVRAM_SIG_OS, NULL);
                 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
-                 */
+                p = nvram_create_partition(part->name, NVRAM_SIG_OS,
+                                        part->req_size, part->min_size);
                 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);
+                        pr_info("nvram: No room to create %s partition, "
+                                "deleting any obsolete OS partitions...\n",
+                                part->name);
+                        nvram_remove_partition(NULL, NVRAM_SIG_OS,
+                                                pseries_nvram_os_partitions);
+                        p = nvram_create_partition(part->name, NVRAM_SIG_OS,
+                                        part->req_size, part->min_size);
                 }
         }
 
         if (p <= 0) {
-                pr_err("nvram: Failed to find or create "NVRAM_LOG_PART_NAME
-                       " partition, err %d\n", (int)p);
-                return 0;
+                pr_err("nvram: Failed to find or create %s"
+                       " partition, err %d\n", part->name, (int)p);
+                return -1;
         }
 
-        nvram_error_log_index = p;
-        nvram_error_log_size = nvram_get_partition_size(p) -
-                sizeof(struct err_log_info);
+        part->index = p;
+        part->size = nvram_get_partition_size(p) - sizeof(struct err_log_info);
         
         return 0;
 }
-machine_arch_initcall(pseries, pseries_nvram_init_log_partition);
+
+static int __init pseries_nvram_init_log_partitions(void)
+{
+        (void) pseries_nvram_init_os_partition(&rtas_log_partition);
+        return 0;
+}
+machine_arch_initcall(pseries, pseries_nvram_init_log_partitions);
 
 int __init pSeries_nvram_init(void)
 {