278 lines
7.5 KiB
C
278 lines
7.5 KiB
C
/*
|
|
* Persistent Storage - pstore.h
|
|
*
|
|
* Copyright (C) 2010 Intel Corporation <tony.luck@intel.com>
|
|
*
|
|
* This code is the generic layer to export data records from platform
|
|
* level persistent storage via a file system.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
#ifndef _LINUX_PSTORE_H
|
|
#define _LINUX_PSTORE_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/kmsg_dump.h>
|
|
#include <linux/mutex.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/time.h>
|
|
#include <linux/types.h>
|
|
|
|
struct module;
|
|
|
|
/* pstore record types (see fs/pstore/inode.c for filename templates) */
|
|
enum pstore_type_id {
|
|
PSTORE_TYPE_DMESG = 0,
|
|
PSTORE_TYPE_MCE = 1,
|
|
PSTORE_TYPE_CONSOLE = 2,
|
|
PSTORE_TYPE_FTRACE = 3,
|
|
/* PPC64 partition types */
|
|
PSTORE_TYPE_PPC_RTAS = 4,
|
|
PSTORE_TYPE_PPC_OF = 5,
|
|
PSTORE_TYPE_PPC_COMMON = 6,
|
|
PSTORE_TYPE_PMSG = 7,
|
|
PSTORE_TYPE_PPC_OPAL = 8,
|
|
PSTORE_TYPE_UNKNOWN = 255
|
|
};
|
|
|
|
struct pstore_info;
|
|
/**
|
|
* struct pstore_record - details of a pstore record entry
|
|
* @psi: pstore backend driver information
|
|
* @type: pstore record type
|
|
* @id: per-type unique identifier for record
|
|
* @time: timestamp of the record
|
|
* @buf: pointer to record contents
|
|
* @size: size of @buf
|
|
* @ecc_notice_size:
|
|
* ECC information for @buf
|
|
*
|
|
* Valid for PSTORE_TYPE_DMESG @type:
|
|
*
|
|
* @count: Oops count since boot
|
|
* @reason: kdump reason for notification
|
|
* @part: position in a multipart record
|
|
* @compressed: whether the buffer is compressed
|
|
*
|
|
*/
|
|
struct pstore_record {
|
|
struct pstore_info *psi;
|
|
enum pstore_type_id type;
|
|
u64 id;
|
|
struct timespec64 time;
|
|
char *buf;
|
|
ssize_t size;
|
|
ssize_t ecc_notice_size;
|
|
|
|
int count;
|
|
enum kmsg_dump_reason reason;
|
|
unsigned int part;
|
|
bool compressed;
|
|
};
|
|
|
|
/**
|
|
* struct pstore_info - backend pstore driver structure
|
|
*
|
|
* @owner: module which is repsonsible for this backend driver
|
|
* @name: name of the backend driver
|
|
*
|
|
* @buf_lock: spinlock to serialize access to @buf
|
|
* @buf: preallocated crash dump buffer
|
|
* @bufsize: size of @buf available for crash dump writes
|
|
*
|
|
* @read_mutex: serializes @open, @read, @close, and @erase callbacks
|
|
* @flags: bitfield of frontends the backend can accept writes for
|
|
* @data: backend-private pointer passed back during callbacks
|
|
*
|
|
* Callbacks:
|
|
*
|
|
* @open:
|
|
* Notify backend that pstore is starting a full read of backend
|
|
* records. Followed by one or more @read calls, and a final @close.
|
|
*
|
|
* @psi: in: pointer to the struct pstore_info for the backend
|
|
*
|
|
* Returns 0 on success, and non-zero on error.
|
|
*
|
|
* @close:
|
|
* Notify backend that pstore has finished a full read of backend
|
|
* records. Always preceded by an @open call and one or more @read
|
|
* calls.
|
|
*
|
|
* @psi: in: pointer to the struct pstore_info for the backend
|
|
*
|
|
* Returns 0 on success, and non-zero on error. (Though pstore will
|
|
* ignore the error.)
|
|
*
|
|
* @read:
|
|
* Read next available backend record. Called after a successful
|
|
* @open.
|
|
*
|
|
* @record:
|
|
* pointer to record to populate. @buf should be allocated
|
|
* by the backend and filled. At least @type and @id should
|
|
* be populated, since these are used when creating pstorefs
|
|
* file names.
|
|
*
|
|
* Returns record size on success, zero when no more records are
|
|
* available, or negative on error.
|
|
*
|
|
* @write:
|
|
* A newly generated record needs to be written to backend storage.
|
|
*
|
|
* @record:
|
|
* pointer to record metadata. When @type is PSTORE_TYPE_DMESG,
|
|
* @buf will be pointing to the preallocated @psi.buf, since
|
|
* memory allocation may be broken during an Oops. Regardless,
|
|
* @buf must be proccesed or copied before returning. The
|
|
* backend is also expected to write @id with something that
|
|
* can help identify this record to a future @erase callback.
|
|
* The @time field will be prepopulated with the current time,
|
|
* when available. The @size field will have the size of data
|
|
* in @buf.
|
|
*
|
|
* Returns 0 on success, and non-zero on error.
|
|
*
|
|
* @write_user:
|
|
* Perform a frontend write to a backend record, using a specified
|
|
* buffer that is coming directly from userspace, instead of the
|
|
* @record @buf.
|
|
*
|
|
* @record: pointer to record metadata.
|
|
* @buf: pointer to userspace contents to write to backend
|
|
*
|
|
* Returns 0 on success, and non-zero on error.
|
|
*
|
|
* @erase:
|
|
* Delete a record from backend storage. Different backends
|
|
* identify records differently, so entire original record is
|
|
* passed back to assist in identification of what the backend
|
|
* should remove from storage.
|
|
*
|
|
* @record: pointer to record metadata.
|
|
*
|
|
* Returns 0 on success, and non-zero on error.
|
|
*
|
|
*/
|
|
struct pstore_info {
|
|
struct module *owner;
|
|
char *name;
|
|
|
|
spinlock_t buf_lock;
|
|
char *buf;
|
|
size_t bufsize;
|
|
|
|
struct mutex read_mutex;
|
|
|
|
int flags;
|
|
void *data;
|
|
|
|
int (*open)(struct pstore_info *psi);
|
|
int (*close)(struct pstore_info *psi);
|
|
ssize_t (*read)(struct pstore_record *record);
|
|
int (*write)(struct pstore_record *record);
|
|
int (*write_user)(struct pstore_record *record,
|
|
const char __user *buf);
|
|
int (*erase)(struct pstore_record *record);
|
|
};
|
|
|
|
/* Supported frontends */
|
|
#define PSTORE_FLAGS_DMESG (1 << 0)
|
|
#define PSTORE_FLAGS_CONSOLE (1 << 1)
|
|
#define PSTORE_FLAGS_FTRACE (1 << 2)
|
|
#define PSTORE_FLAGS_PMSG (1 << 3)
|
|
|
|
extern int pstore_register(struct pstore_info *);
|
|
extern void pstore_unregister(struct pstore_info *);
|
|
extern bool pstore_cannot_block_path(enum kmsg_dump_reason reason);
|
|
|
|
struct pstore_ftrace_record {
|
|
unsigned long ip;
|
|
unsigned long parent_ip;
|
|
u64 ts;
|
|
};
|
|
|
|
/*
|
|
* ftrace related stuff: Both backends and frontends need these so expose
|
|
* them here.
|
|
*/
|
|
|
|
#if NR_CPUS <= 2 && defined(CONFIG_ARM_THUMB)
|
|
#define PSTORE_CPU_IN_IP 0x1
|
|
#elif NR_CPUS <= 4 && defined(CONFIG_ARM)
|
|
#define PSTORE_CPU_IN_IP 0x3
|
|
#endif
|
|
|
|
#define TS_CPU_SHIFT 8
|
|
#define TS_CPU_MASK (BIT(TS_CPU_SHIFT) - 1)
|
|
|
|
/*
|
|
* If CPU number can be stored in IP, store it there, otherwise store it in
|
|
* the time stamp. This means more timestamp resolution is available when
|
|
* the CPU can be stored in the IP.
|
|
*/
|
|
#ifdef PSTORE_CPU_IN_IP
|
|
static inline void
|
|
pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
|
|
{
|
|
rec->ip |= cpu;
|
|
}
|
|
|
|
static inline unsigned int
|
|
pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
|
|
{
|
|
return rec->ip & PSTORE_CPU_IN_IP;
|
|
}
|
|
|
|
static inline u64
|
|
pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
|
|
{
|
|
return rec->ts;
|
|
}
|
|
|
|
static inline void
|
|
pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
|
|
{
|
|
rec->ts = val;
|
|
}
|
|
#else
|
|
static inline void
|
|
pstore_ftrace_encode_cpu(struct pstore_ftrace_record *rec, unsigned int cpu)
|
|
{
|
|
rec->ts &= ~(TS_CPU_MASK);
|
|
rec->ts |= cpu;
|
|
}
|
|
|
|
static inline unsigned int
|
|
pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec)
|
|
{
|
|
return rec->ts & TS_CPU_MASK;
|
|
}
|
|
|
|
static inline u64
|
|
pstore_ftrace_read_timestamp(struct pstore_ftrace_record *rec)
|
|
{
|
|
return rec->ts >> TS_CPU_SHIFT;
|
|
}
|
|
|
|
static inline void
|
|
pstore_ftrace_write_timestamp(struct pstore_ftrace_record *rec, u64 val)
|
|
{
|
|
rec->ts = (rec->ts & TS_CPU_MASK) | (val << TS_CPU_SHIFT);
|
|
}
|
|
#endif
|
|
|
|
#endif /*_LINUX_PSTORE_H*/
|