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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
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40
arch/x86/kernel/cpu/mcheck/mce-apei.c
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@ -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 */