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