xref: /openbmc/linux/include/linux/pstore_ram.h (revision 0c7beb2d)
1 /*
2  * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
3  * Copyright (C) 2011 Kees Cook <keescook@chromium.org>
4  * Copyright (C) 2011 Google, Inc.
5  *
6  * This software is licensed under the terms of the GNU General Public
7  * License version 2, as published by the Free Software Foundation, and
8  * may be copied, distributed, and modified under those terms.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  */
16 
17 #ifndef __LINUX_PSTORE_RAM_H__
18 #define __LINUX_PSTORE_RAM_H__
19 
20 #include <linux/compiler.h>
21 #include <linux/device.h>
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/list.h>
25 #include <linux/pstore.h>
26 #include <linux/types.h>
27 
28 /*
29  * Choose whether access to the RAM zone requires locking or not.  If a zone
30  * can be written to from different CPUs like with ftrace for example, then
31  * PRZ_FLAG_NO_LOCK is used. For all other cases, locking is required.
32  */
33 #define PRZ_FLAG_NO_LOCK	BIT(0)
34 /*
35  * If a PRZ should only have a single-boot lifetime, this marks it as
36  * getting wiped after its contents get copied out after boot.
37  */
38 #define PRZ_FLAG_ZAP_OLD	BIT(1)
39 
40 struct persistent_ram_buffer;
41 struct rs_control;
42 
43 struct persistent_ram_ecc_info {
44 	int block_size;
45 	int ecc_size;
46 	int symsize;
47 	int poly;
48 	uint16_t *par;
49 };
50 
51 /**
52  * struct persistent_ram_zone - Details of a persistent RAM zone (PRZ)
53  *                              used as a pstore backend
54  *
55  * @paddr:	physical address of the mapped RAM area
56  * @size:	size of mapping
57  * @label:	unique name of this PRZ
58  * @type:	frontend type for this PRZ
59  * @flags:	holds PRZ_FLAGS_* bits
60  *
61  * @buffer_lock:
62  *	locks access to @buffer "size" bytes and "start" offset
63  * @buffer:
64  *	pointer to actual RAM area managed by this PRZ
65  * @buffer_size:
66  *	bytes in @buffer->data (not including any trailing ECC bytes)
67  *
68  * @par_buffer:
69  *	pointer into @buffer->data containing ECC bytes for @buffer->data
70  * @par_header:
71  *	pointer into @buffer->data containing ECC bytes for @buffer header
72  *	(i.e. all fields up to @data)
73  * @rs_decoder:
74  *	RSLIB instance for doing ECC calculations
75  * @corrected_bytes:
76  *	ECC corrected bytes accounting since boot
77  * @bad_blocks:
78  *	ECC uncorrectable bytes accounting since boot
79  * @ecc_info:
80  *	ECC configuration details
81  *
82  * @old_log:
83  *	saved copy of @buffer->data prior to most recent wipe
84  * @old_log_size:
85  *	bytes contained in @old_log
86  *
87  */
88 struct persistent_ram_zone {
89 	phys_addr_t paddr;
90 	size_t size;
91 	void *vaddr;
92 	char *label;
93 	enum pstore_type_id type;
94 	u32 flags;
95 
96 	raw_spinlock_t buffer_lock;
97 	struct persistent_ram_buffer *buffer;
98 	size_t buffer_size;
99 
100 	char *par_buffer;
101 	char *par_header;
102 	struct rs_control *rs_decoder;
103 	int corrected_bytes;
104 	int bad_blocks;
105 	struct persistent_ram_ecc_info ecc_info;
106 
107 	char *old_log;
108 	size_t old_log_size;
109 };
110 
111 struct persistent_ram_zone *persistent_ram_new(phys_addr_t start, size_t size,
112 			u32 sig, struct persistent_ram_ecc_info *ecc_info,
113 			unsigned int memtype, u32 flags, char *label);
114 void persistent_ram_free(struct persistent_ram_zone *prz);
115 void persistent_ram_zap(struct persistent_ram_zone *prz);
116 
117 int persistent_ram_write(struct persistent_ram_zone *prz, const void *s,
118 			 unsigned int count);
119 int persistent_ram_write_user(struct persistent_ram_zone *prz,
120 			      const void __user *s, unsigned int count);
121 
122 void persistent_ram_save_old(struct persistent_ram_zone *prz);
123 size_t persistent_ram_old_size(struct persistent_ram_zone *prz);
124 void *persistent_ram_old(struct persistent_ram_zone *prz);
125 void persistent_ram_free_old(struct persistent_ram_zone *prz);
126 ssize_t persistent_ram_ecc_string(struct persistent_ram_zone *prz,
127 	char *str, size_t len);
128 
129 /*
130  * Ramoops platform data
131  * @mem_size	memory size for ramoops
132  * @mem_address	physical memory address to contain ramoops
133  */
134 
135 #define RAMOOPS_FLAG_FTRACE_PER_CPU	BIT(0)
136 
137 struct ramoops_platform_data {
138 	unsigned long	mem_size;
139 	phys_addr_t	mem_address;
140 	unsigned int	mem_type;
141 	unsigned long	record_size;
142 	unsigned long	console_size;
143 	unsigned long	ftrace_size;
144 	unsigned long	pmsg_size;
145 	int		dump_oops;
146 	u32		flags;
147 	struct persistent_ram_ecc_info ecc_info;
148 };
149 
150 #endif
151