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ACPI, APEI, Add ERST record ID cache

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APEI ERST firmware interface and implementation has no multiple users
in mind.  For example, if there is four records in storage with ID: 1,
2, 3 and 4, if two ERST readers enumerate the records via
GET_NEXT_RECORD_ID as follow,

reader 1		reader 2
1
			2
3
			4
-1
			-1

where -1 signals there is no more record ID.

Reader 1 has no chance to check record 2 and 4, while reader 2 has no
chance to check record 1 and 3.  And any other GET_NEXT_RECORD_ID will
return -1, that is, other readers will has no chance to check any
record even they are not cleared by anyone.

This makes raw GET_NEXT_RECORD_ID not suitable for used by multiple
users.

To solve the issue, an in-memory ERST record ID cache is designed and
implemented.  When enumerating record ID, the ID returned by
GET_NEXT_RECORD_ID is added into cache in addition to be returned to
caller.  So other readers can check the cache to get all record ID
available.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Huang Ying 2011-02-21 13:54:41 +08:00 committed by Len Brown
parent dd9c1549ed
commit 885b976fad
4 changed files with 240 additions and 64 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
arch/x86/kernel/cpu/mcheck/mce-apei.c
View File

@ -106,24 +106,34 @@ int apei_write_mce(struct mce *m)
ssize_t apei_read_mce(struct mce *m, u64 *record_id)
{
struct cper_mce_record rcd;
ssize_t len;
len = erst_read_next(&rcd.hdr, sizeof(rcd));
if (len <= 0)
return len;
/* Can not skip other records in storage via ERST unless clear them */
else if (len != sizeof(rcd) ||
uuid_le_cmp(rcd.hdr.creator_id, CPER_CREATOR_MCE)) {
if (printk_ratelimit())
pr_warning(
"MCE-APEI: Can not skip the unknown record in ERST");
return -EIO;
}
int rc, pos;
rc = erst_get_record_id_begin(&pos);
if (rc)
return rc;
retry:
rc = erst_get_record_id_next(&pos, record_id);
if (rc)
goto out;
/* no more record */
if (*record_id == APEI_ERST_INVALID_RECORD_ID)
goto out;
rc = erst_read(*record_id, &rcd.hdr, sizeof(rcd));
/* someone else has cleared the record, try next one */
if (rc == -ENOENT)
goto retry;
else if (rc < 0)
goto out;
/* try to skip other type records in storage */
else if (rc != sizeof(rcd) ||
uuid_le_cmp(rcd.hdr.creator_id, CPER_CREATOR_MCE))
goto retry;
memcpy(m, &rcd.mce, sizeof(*m));
*record_id = rcd.hdr.record_id;
rc = sizeof(*m);
out:
erst_get_record_id_end();
return sizeof(*m);
return rc;
}
/* Check whether there is record in ERST */

24
drivers/acpi/apei/erst-dbg.c
View File

@ -43,12 +43,27 @@ static DEFINE_MUTEX(erst_dbg_mutex);
static int erst_dbg_open(struct inode *inode, struct file *file)
{
int rc, *pos;
if (erst_disable)
return -ENODEV;
pos = (int *)&file->private_data;
rc = erst_get_record_id_begin(pos);
if (rc)
return rc;
return nonseekable_open(inode, file);
}
static int erst_dbg_release(struct inode *inode, struct file *file)
{
erst_get_record_id_end();
return 0;
}
static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
int rc;
@ -79,18 +94,20 @@ static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf,
size_t usize, loff_t *off)
{
int rc;
int rc, *pos;
ssize_t len = 0;
u64 id;
if (*off != 0)
if (*off)
return -EINVAL;
if (mutex_lock_interruptible(&erst_dbg_mutex) != 0)
return -EINTR;
pos = (int *)&filp->private_data;
retry_next:
rc = erst_get_next_record_id(&id);
rc = erst_get_record_id_next(pos, &id);
if (rc)
goto out;
/* no more record */
@ -181,6 +198,7 @@ out:
static const struct file_operations erst_dbg_ops = {
.owner = THIS_MODULE,
.open = erst_dbg_open,
.release = erst_dbg_release,
.read = erst_dbg_read,
.write = erst_dbg_write,
.unlocked_ioctl = erst_dbg_ioctl,

235
drivers/acpi/apei/erst.c
View File

@ -429,6 +429,22 @@ ssize_t erst_get_record_count(void)
}
EXPORT_SYMBOL_GPL(erst_get_record_count);
#define ERST_RECORD_ID_CACHE_SIZE_MIN 16
#define ERST_RECORD_ID_CACHE_SIZE_MAX 1024
struct erst_record_id_cache {
struct mutex lock;
u64 *entries;
int len;
int size;
int refcount;
};
static struct erst_record_id_cache erst_record_id_cache = {
.lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
.refcount = 0,
};
static int __erst_get_next_record_id(u64 *record_id)
{
struct apei_exec_context ctx;
@ -443,26 +459,179 @@ static int __erst_get_next_record_id(u64 *record_id)
return 0;
}
int erst_get_record_id_begin(int *pos)
{
int rc;
if (erst_disable)
return -ENODEV;
rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
if (rc)
return rc;
erst_record_id_cache.refcount++;
mutex_unlock(&erst_record_id_cache.lock);
*pos = 0;
return 0;
}
EXPORT_SYMBOL_GPL(erst_get_record_id_begin);
/* erst_record_id_cache.lock must be held by caller */
static int __erst_record_id_cache_add_one(void)
{
u64 id, prev_id, first_id;
int i, rc;
u64 *entries;
unsigned long flags;
id = prev_id = first_id = APEI_ERST_INVALID_RECORD_ID;
retry:
raw_spin_lock_irqsave(&erst_lock, flags);
rc = __erst_get_next_record_id(&id);
raw_spin_unlock_irqrestore(&erst_lock, flags);
if (rc == -ENOENT)
return 0;
if (rc)
return rc;
if (id == APEI_ERST_INVALID_RECORD_ID)
return 0;
/* can not skip current ID, or loop back to first ID */
if (id == prev_id || id == first_id)
return 0;
if (first_id == APEI_ERST_INVALID_RECORD_ID)
first_id = id;
prev_id = id;
entries = erst_record_id_cache.entries;
for (i = 0; i < erst_record_id_cache.len; i++) {
if (entries[i] == id)
break;
}
/* record id already in cache, try next */
if (i < erst_record_id_cache.len)
goto retry;
if (erst_record_id_cache.len >= erst_record_id_cache.size) {
int new_size, alloc_size;
u64 *new_entries;
new_size = erst_record_id_cache.size * 2;
new_size = clamp_val(new_size, ERST_RECORD_ID_CACHE_SIZE_MIN,
ERST_RECORD_ID_CACHE_SIZE_MAX);
if (new_size <= erst_record_id_cache.size) {
if (printk_ratelimit())
pr_warning(FW_WARN ERST_PFX
"too many record ID!\n");
return 0;
}
alloc_size = new_size * sizeof(entries[0]);
if (alloc_size < PAGE_SIZE)
new_entries = kmalloc(alloc_size, GFP_KERNEL);
else
new_entries = vmalloc(alloc_size);
if (!new_entries)
return -ENOMEM;
memcpy(new_entries, entries,
erst_record_id_cache.len * sizeof(entries[0]));
if (erst_record_id_cache.size < PAGE_SIZE)
kfree(entries);
else
vfree(entries);
erst_record_id_cache.entries = entries = new_entries;
erst_record_id_cache.size = new_size;
}
entries[i] = id;
erst_record_id_cache.len++;
return 1;
}
/*
* Get the record ID of an existing error record on the persistent
* storage. If there is no error record on the persistent storage, the
* returned record_id is APEI_ERST_INVALID_RECORD_ID.
*/
int erst_get_next_record_id(u64 *record_id)
int erst_get_record_id_next(int *pos, u64 *record_id)
{
int rc;
unsigned long flags;
int rc = 0;
u64 *entries;
if (erst_disable)
return -ENODEV;
raw_spin_lock_irqsave(&erst_lock, flags);
rc = __erst_get_next_record_id(record_id);
raw_spin_unlock_irqrestore(&erst_lock, flags);
/* must be enclosed by erst_get_record_id_begin/end */
BUG_ON(!erst_record_id_cache.refcount);
BUG_ON(*pos < 0 || *pos > erst_record_id_cache.len);
mutex_lock(&erst_record_id_cache.lock);
entries = erst_record_id_cache.entries;
for (; *pos < erst_record_id_cache.len; (*pos)++)
if (entries[*pos] != APEI_ERST_INVALID_RECORD_ID)
break;
/* found next record id in cache */
if (*pos < erst_record_id_cache.len) {
*record_id = entries[*pos];
(*pos)++;
goto out_unlock;
}
/* Try to add one more record ID to cache */
rc = __erst_record_id_cache_add_one();
if (rc < 0)
goto out_unlock;
/* successfully add one new ID */
if (rc == 1) {
*record_id = erst_record_id_cache.entries[*pos];
(*pos)++;
rc = 0;
} else {
*pos = -1;
*record_id = APEI_ERST_INVALID_RECORD_ID;
}
out_unlock:
mutex_unlock(&erst_record_id_cache.lock);
return rc;
}
EXPORT_SYMBOL_GPL(erst_get_next_record_id);
EXPORT_SYMBOL_GPL(erst_get_record_id_next);
/* erst_record_id_cache.lock must be held by caller */
static void __erst_record_id_cache_compact(void)
{
int i, wpos = 0;
u64 *entries;
if (erst_record_id_cache.refcount)
return;
entries = erst_record_id_cache.entries;
for (i = 0; i < erst_record_id_cache.len; i++) {
if (entries[i] == APEI_ERST_INVALID_RECORD_ID)
continue;
if (wpos != i)
memcpy(&entries[wpos], &entries[i], sizeof(entries[i]));
wpos++;
}
erst_record_id_cache.len = wpos;
}
void erst_get_record_id_end(void)
{
/*
* erst_disable != 0 should be detected by invoker via the
* return value of erst_get_record_id_begin/next, so this
* function should not be called for erst_disable != 0.
*/
BUG_ON(erst_disable);
mutex_lock(&erst_record_id_cache.lock);
erst_record_id_cache.refcount--;
BUG_ON(erst_record_id_cache.refcount < 0);
__erst_record_id_cache_compact();
mutex_unlock(&erst_record_id_cache.lock);
}
EXPORT_SYMBOL_GPL(erst_get_record_id_end);
static int __erst_write_to_storage(u64 offset)
{
@ -703,56 +872,34 @@ ssize_t erst_read(u64 record_id, struct cper_record_header *record,
}
EXPORT_SYMBOL_GPL(erst_read);
/*
* If return value > buflen, the buffer size is not big enough,
* else if return value = 0, there is no more record to read,
* else if return value < 0, something goes wrong,
* else everything is OK, and return value is record length
*/
ssize_t erst_read_next(struct cper_record_header *record, size_t buflen)
{
int rc;
ssize_t len;
unsigned long flags;
u64 record_id;
if (erst_disable)
return -ENODEV;
raw_spin_lock_irqsave(&erst_lock, flags);
rc = __erst_get_next_record_id(&record_id);
if (rc) {
raw_spin_unlock_irqrestore(&erst_lock, flags);
return rc;
}
/* no more record */
if (record_id == APEI_ERST_INVALID_RECORD_ID) {
raw_spin_unlock_irqrestore(&erst_lock, flags);
return 0;
}
len = __erst_read(record_id, record, buflen);
raw_spin_unlock_irqrestore(&erst_lock, flags);
return len;
}
EXPORT_SYMBOL_GPL(erst_read_next);
int erst_clear(u64 record_id)
{
int rc;
int rc, i;
unsigned long flags;
u64 *entries;
if (erst_disable)
return -ENODEV;
rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
if (rc)
return rc;
raw_spin_lock_irqsave(&erst_lock, flags);
if (erst_erange.attr & ERST_RANGE_NVRAM)
rc = __erst_clear_from_nvram(record_id);
else
rc = __erst_clear_from_storage(record_id);
raw_spin_unlock_irqrestore(&erst_lock, flags);
if (rc)
goto out;
entries = erst_record_id_cache.entries;
for (i = 0; i < erst_record_id_cache.len; i++) {
if (entries[i] == record_id)
entries[i] = APEI_ERST_INVALID_RECORD_ID;
}
__erst_record_id_cache_compact();
out:
mutex_unlock(&erst_record_id_cache.lock);
return rc;
}
EXPORT_SYMBOL_GPL(erst_clear);

5
include/acpi/apei.h
View File

@ -30,10 +30,11 @@ int apei_hest_parse(apei_hest_func_t func, void *data);
int erst_write(const struct cper_record_header *record);
ssize_t erst_get_record_count(void);
int erst_get_next_record_id(u64 *record_id);
int erst_get_record_id_begin(int *pos);
int erst_get_record_id_next(int *pos, u64 *record_id);
void erst_get_record_id_end(void);
ssize_t erst_read(u64 record_id, struct cper_record_header *record,
size_t buflen);
ssize_t erst_read_next(struct cper_record_header *record, size_t buflen);
int erst_clear(u64 record_id);
#endif