blob: 61e914522b01936d9f3b524888013354c90638e5 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PSTORE_BLK_H_
#define __PSTORE_BLK_H_
#include <linux/types.h>
#include <linux/pstore.h>
#include <linux/pstore_zone.h>
* typedef pstore_blk_panic_write_op - panic write operation to block device
* @buf: the data to write
* @start_sect: start sector to block device
* @sects: sectors count on buf
* Return: On success, zero should be returned. Others excluding -ENOMSG
* mean error. -ENOMSG means to try next zone.
* Panic write to block device must be aligned to SECTOR_SIZE.
typedef int (*pstore_blk_panic_write_op)(const char *buf, sector_t start_sect,
sector_t sects);
* struct pstore_blk_info - pstore/blk registration details
* @major: Which major device number to support with pstore/blk
* @flags: The supported PSTORE_FLAGS_* from linux/pstore.h.
* @panic_write:The write operation only used for the panic case.
* This can be NULL, but is recommended to avoid losing
* crash data if the kernel's IO path or work queues are
* broken during a panic.
* @devt: The dev_t that pstore/blk has attached to.
* @nr_sects: Number of sectors on @devt.
* @start_sect: Starting sector on @devt.
struct pstore_blk_info {
unsigned int major;
unsigned int flags;
pstore_blk_panic_write_op panic_write;
/* Filled in by pstore/blk after registration. */
dev_t devt;
sector_t nr_sects;
sector_t start_sect;
int register_pstore_blk(struct pstore_blk_info *info);
void unregister_pstore_blk(unsigned int major);
* struct pstore_device_info - back-end pstore/blk driver structure.
* @total_size: The total size in bytes pstore/blk can use. It must be greater
* than 4096 and be multiple of 4096.
* @flags: Refer to macro starting with PSTORE_FLAGS defined in
* linux/pstore.h. It means what front-ends this device support.
* Zero means all backends for compatible.
* @read: The general read operation. Both of the function parameters
* @size and @offset are relative value to bock device (not the
* whole disk).
* On success, the number of bytes should be returned, others
* means error.
* @write: The same as @read, but the following error number:
* -EBUSY means try to write again later.
* -ENOMSG means to try next zone.
* @erase: The general erase operation for device with special removing
* job. Both of the function parameters @size and @offset are
* relative value to storage.
* Return 0 on success and others on failure.
* @panic_write:The write operation only used for panic case. It's optional
* if you do not care panic log. The parameters are relative
* value to storage.
* On success, the number of bytes should be returned, others
* excluding -ENOMSG mean error. -ENOMSG means to try next zone.
struct pstore_device_info {
unsigned long total_size;
unsigned int flags;
pstore_zone_read_op read;
pstore_zone_write_op write;
pstore_zone_erase_op erase;
pstore_zone_write_op panic_write;
int register_pstore_device(struct pstore_device_info *dev);
void unregister_pstore_device(struct pstore_device_info *dev);
* struct pstore_blk_config - the pstore_blk backend configuration
* @device: Name of the desired block device
* @max_reason: Maximum kmsg dump reason to store to block device
* @kmsg_size: Total size of for kmsg dumps
* @pmsg_size: Total size of the pmsg storage area
* @console_size: Total size of the console storage area
* @ftrace_size: Total size for ftrace logging data (for all CPUs)
struct pstore_blk_config {
char device[80];
enum kmsg_dump_reason max_reason;
unsigned long kmsg_size;
unsigned long pmsg_size;
unsigned long console_size;
unsigned long ftrace_size;
* pstore_blk_get_config - get a copy of the pstore_blk backend configuration
* @info: The sturct pstore_blk_config to be filled in
* Failure returns negative error code, and success returns 0.
int pstore_blk_get_config(struct pstore_blk_config *info);