1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
4 * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
5 * Copyright (C) 2011 Google, Inc.
6 */
7
8 #include <linux/pstore_ram.h>
9
10 /*
11 * Choose whether access to the RAM zone requires locking or not. If a zone
12 * can be written to from different CPUs like with ftrace for example, then
13 * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required.
14 */
15 #define PRZ_FLAG_NO_LOCK BIT(0)
16 /*
17 * If a PRZ should only have a single-boot lifetime, this marks it as
18 * getting wiped after its contents get copied out after boot.
19 */
20 #define PRZ_FLAG_ZAP_OLD BIT(1)
21
22 /**
23 * struct persistent_ram_zone - Details of a persistent RAM zone (PRZ)
24 * used as a pstore backend
25 *
26 * @paddr: physical address of the mapped RAM area
27 * @size: size of mapping
28 * @label: unique name of this PRZ
29 * @type: frontend type for this PRZ
30 * @flags: holds PRZ_FLAGS_* bits
31 *
32 * @buffer_lock:
33 * locks access to @buffer "size" bytes and "start" offset
34 * @buffer:
35 * pointer to actual RAM area managed by this PRZ
36 * @buffer_size:
37 * bytes in @buffer->data (not including any trailing ECC bytes)
38 *
39 * @par_buffer:
40 * pointer into @buffer->data containing ECC bytes for @buffer->data
41 * @par_header:
42 * pointer into @buffer->data containing ECC bytes for @buffer header
43 * (i.e. all fields up to @data)
44 * @rs_decoder:
45 * RSLIB instance for doing ECC calculations
46 * @corrected_bytes:
47 * ECC corrected bytes accounting since boot
48 * @bad_blocks:
49 * ECC uncorrectable bytes accounting since boot
50 * @ecc_info:
51 * ECC configuration details
52 *
53 * @old_log:
54 * saved copy of @buffer->data prior to most recent wipe
55 * @old_log_size:
56 * bytes contained in @old_log
57 *
58 */
59 struct persistent_ram_zone {
60 phys_addr_t paddr;
61 size_t size;
62 void *vaddr;
63 char *label;
64 enum pstore_type_id type;
65 u32 flags;
66
67 raw_spinlock_t buffer_lock;
68 struct persistent_ram_buffer *buffer;
69 size_t buffer_size;
70
71 char *par_buffer;
72 char *par_header;
73 struct rs_control *rs_decoder;
74 int corrected_bytes;
75 int bad_blocks;
76 struct persistent_ram_ecc_info ecc_info;
77
78 char *old_log;
79 size_t old_log_size;
80 };
81
82 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
83 u32 sig, struct persistent_ram_ecc_info *ecc_info,
84 unsigned int memtype, u32 flags, char *label);
85 void persistent_ram_free(struct persistent_ram_zone **_prz);
86 void persistent_ram_zap(struct persistent_ram_zone *prz);
87
88 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
89 unsigned int count);
90 int persistent_ram_write_user(struct persistent_ram_zone *prz,
91 const void __user *s, unsigned int count);
92
93 void persistent_ram_save_old(struct persistent_ram_zone *prz);
94 size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
95 void *persistent_ram_old(struct persistent_ram_zone *prz);
96 void persistent_ram_free_old(struct persistent_ram_zone *prz);
97 ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
98 char *str, size_t len);
99
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