linux/include/acpi/apei.h
Huang Ying 885b976fad ACPI, APEI, Add ERST record ID cache
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>
2011-03-21 22:59:06 -04:00

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1016 B
C

/*
* apei.h - ACPI Platform Error Interface
*/
#ifndef ACPI_APEI_H
#define ACPI_APEI_H
#include <linux/acpi.h>
#include <linux/cper.h>
#include <asm/ioctls.h>
#define APEI_ERST_INVALID_RECORD_ID 0xffffffffffffffffULL
#define APEI_ERST_CLEAR_RECORD _IOW('E', 1, u64)
#define APEI_ERST_GET_RECORD_COUNT _IOR('E', 2, u32)
#ifdef __KERNEL__
extern int hest_disable;
extern int erst_disable;
#ifdef CONFIG_ACPI_APEI
void __init acpi_hest_init(void);
#else
static inline void acpi_hest_init(void) { return; }
#endif
typedef int (*apei_hest_func_t)(struct acpi_hest_header *hest_hdr, void *data);
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_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);
int erst_clear(u64 record_id);
#endif
#endif