[PATCH 1/6] nvram: Generalize code for OS partitions in NVRAM
Jim Keniston
jkenisto at linux.vnet.ibm.com
Thu Feb 10 09:43:13 EST 2011
On Mon, 2011-02-07 at 15:57 +1100, Benjamin Herrenschmidt wrote:
> On Sat, 2010-11-13 at 20:15 -0800, Jim Keniston wrote:
> > 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 at us.ibm.com>
> > ---
>
> Overall pretty good (sorry for taking that long to review, I've been
> swamped down). Just a handful of minor nits:
I've appended an updated patch, which addresses your comments and also
applies to 2.6.38-rc4, rather than to your kernel as it stood on Nov.
13. See below for responses to comments.
>
> > +/*
> > + * Per the criteria passed via nvram_remove_partition(), should this
> > + * partition be removed? 1=remove, 0=keep
> > + */
> > +static int nvram_condemn_partition(struct nvram_partition *part,
> > + const char *name, int sig, const char *exceptions[])
>
> As "fun" as this name is, it didn't help me understand what the function
> was about until I read the code for the next one :-)
>
> What about instead something like nvram_can_remove_partition() or
> something a bit more explicit like that ?
Done.
...
> .../...
>
> > +static const char *valid_os_partitions[] = {
> > + "ibm,rtas-log",
> > + NULL
> > +};
>
> Can you pick a name that will be less confusing in the global
> symbol table ? Something like "pseries_nvram_os_partitions"
Done.
> or whatever shorter you can come up with which doesn't suck ?
>
> Also, should we move that "os partition" core out of pseries ?
>
> Looks like it will be useful for a few other platforms, I'd like
> to move that to a more generically useful location in arch/powerpc
> but that's not a blocker for this series but something to do next
> maybe ?
I haven't tried to do that reorganization.
>
> In that case "struct os_partition" should also find itself a better
> name, maybe struct nvram_os_partition ?
Done.
...
> > if (rc <= 0) {
> > - printk(KERN_ERR "nvram_write_error_log: Failed nvram_write (%d)\n", rc);
> > + printk(KERN_ERR "nvram_write_os_partition: Failed nvram_write (%d)\n", rc);
> > return rc;
> > }
> >
> > return 0;
> > }
>
> While at it, turn these into pr_err and use __FUNCTION__ or __func__
Done. However, I didn't convert any printks in functions that I wasn't
otherwise changing.
>
> > +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);
> > +}
>
> That's a candidate for a static inline in a .h
Maybe, but in my next patch this function adjusts a static variable, so
I figure that putting it in a header would be messy.
Here's my revised patch.
Jim
=====
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 at us.ibm.com>
---
arch/powerpc/include/asm/nvram.h | 3 -
arch/powerpc/kernel/nvram_64.c | 31 ++++++-
arch/powerpc/platforms/pseries/nvram.c | 143 +++++++++++++++++++-------------
3 files changed, 113 insertions(+), 64 deletions(-)
diff --git a/arch/powerpc/include/asm/nvram.h b/arch/powerpc/include/asm/nvram.h
index 92efe67..9d1aafe 100644
--- a/arch/powerpc/include/asm/nvram.h
+++ b/arch/powerpc/include/asm/nvram.h
@@ -51,7 +51,8 @@ static inline int mmio_nvram_init(void)
extern int __init nvram_scan_partitions(void);
extern loff_t nvram_create_partition(const char *name, int sig,
int req_size, int min_size);
-extern int nvram_remove_partition(const char *name, int sig);
+extern int nvram_remove_partition(const char *name, int sig,
+ const char *exceptions[]);
extern int nvram_get_partition_size(loff_t data_index);
extern loff_t nvram_find_partition(const char *name, int sig, int *out_size);
diff --git a/arch/powerpc/kernel/nvram_64.c b/arch/powerpc/kernel/nvram_64.c
index bb12b32..bec1e93 100644
--- a/arch/powerpc/kernel/nvram_64.c
+++ b/arch/powerpc/kernel/nvram_64.c
@@ -237,22 +237,45 @@ static unsigned char __init nvram_checksum(struct nvram_header *p)
return c_sum;
}
+/*
+ * Per the criteria passed via nvram_remove_partition(), should this
+ * partition be removed? 1=remove, 0=keep
+ */
+static int nvram_can_remove_partition(struct nvram_partition *part,
+ const char *name, int sig, const char *exceptions[])
+{
+ if (part->header.signature != sig)
+ return 0;
+ if (name) {
+ if (strncmp(name, part->header.name, 12))
+ return 0;
+ } else if (exceptions) {
+ const char **except;
+ for (except = exceptions; *except; except++) {
+ if (!strncmp(*except, part->header.name, 12))
+ return 0;
+ }
+ }
+ return 1;
+}
+
/**
* nvram_remove_partition - Remove one or more partitions in nvram
* @name: name of the partition to remove, or NULL for a
* signature only match
* @sig: signature of the partition(s) to remove
+ * @exceptions: When removing all partitions with a matching signature,
+ * leave these alone.
*/
-int __init nvram_remove_partition(const char *name, int sig)
+int __init nvram_remove_partition(const char *name, int sig,
+ const char *exceptions[])
{
struct nvram_partition *part, *prev, *tmp;
int rc;
list_for_each_entry(part, &nvram_partitions, partition) {
- if (part->header.signature != sig)
- continue;
- if (name && strncmp(name, part->header.name, 12))
+ if (!nvram_can_remove_partition(part, name, sig, exceptions))
continue;
/* Make partition a free partition */
diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
index 7e828ba..befb41b 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)
{
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