LXR linux/include/linux/pstore

   1/* SPDX-License-Identifier: GPL-2.0 */
   2
   3#ifndef __PSTORE_ZONE_H_
   4#define __PSTORE_ZONE_H_
   5
   6#include <linux/types.h>
   7
   8typedef ssize_t (*pstore_zone_read_op)(char *, size_t, loff_t);
   9typedef ssize_t (*pstore_zone_write_op)(const char *, size_t, loff_t);
  10typedef ssize_t (*pstore_zone_erase_op)(size_t, loff_t);
  11/**
  12 * struct pstore_zone_info - pstore/zone back-end driver structure
  13 *
  14 * @owner:      Module which is responsible for this back-end driver.
  15 * @name:       Name of the back-end driver.
  16 * @total_size: The total size in bytes pstore/zone can use. It must be greater
  17 *              than 4096 and be multiple of 4096.
  18 * @kmsg_size:  The size of oops/panic zone. Zero means disabled, otherwise,
  19 *              it must be multiple of SECTOR_SIZE(512 Bytes).
  20 * @max_reason: Maximum kmsg dump reason to store.
  21 * @pmsg_size:  The size of pmsg zone which is the same as @kmsg_size.
  22 * @console_size:The size of console zone which is the same as @kmsg_size.
  23 * @ftrace_size:The size of ftrace zone which is the same as @kmsg_size.
  24 * @read:       The general read operation. Both of the function parameters
  25 *              @size and @offset are relative value to storage.
  26 *              On success, the number of bytes should be returned, others
  27 *              mean error.
  28 * @write:      The same as @read, but the following error number:
  29 *              -EBUSY means try to write again later.
  30 *              -ENOMSG means to try next zone.
  31 * @erase:      The general erase operation for device with special removing
  32 *              job. Both of the function parameters @size and @offset are
  33 *              relative value to storage.
  34 *              Return 0 on success and others on failure.
  35 * @panic_write:The write operation only used for panic case. It's optional
  36 *              if you do not care panic log. The parameters are relative
  37 *              value to storage.
  38 *              On success, the number of bytes should be returned, others
  39 *              excluding -ENOMSG mean error. -ENOMSG means to try next zone.
  40 */
  41struct pstore_zone_info {
  42        struct module *owner;
  43        const char *name;
  44
  45        unsigned long total_size;
  46        unsigned long kmsg_size;
  47        int max_reason;
  48        unsigned long pmsg_size;
  49        unsigned long console_size;
  50        unsigned long ftrace_size;
  51        pstore_zone_read_op read;
  52        pstore_zone_write_op write;
  53        pstore_zone_erase_op erase;
  54        pstore_zone_write_op panic_write;
  55};
  56
  57extern int register_pstore_zone(struct pstore_zone_info *info);
  58extern void unregister_pstore_zone(struct pstore_zone_info *info);
  59
  60#endif
  61