xref: /aosp_15_r20/external/coreboot/src/include/smmstore.h (revision b9411a12aaaa7e1e6a6fb7c5e057f44ee179a49c)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 
3 #ifndef _SMMSTORE_H_
4 #define _SMMSTORE_H_
5 
6 #include <stddef.h>
7 #include <stdint.h>
8 
9 #define SMMSTORE_RET_SUCCESS 0
10 #define SMMSTORE_RET_FAILURE 1
11 #define SMMSTORE_RET_UNSUPPORTED 2
12 
13 /* Version 1 */
14 #define SMMSTORE_CMD_CLEAR 1
15 #define SMMSTORE_CMD_READ 2
16 #define SMMSTORE_CMD_APPEND 3
17 
18 /* Version 2 */
19 #define SMMSTORE_CMD_INIT_DEPRECATED 4
20 #define SMMSTORE_CMD_RAW_READ 5
21 #define SMMSTORE_CMD_RAW_WRITE 6
22 #define SMMSTORE_CMD_RAW_CLEAR 7
23 
24 /* Version 1 */
25 struct smmstore_params_read {
26 	void *buf;
27 	ssize_t bufsize;
28 };
29 
30 struct smmstore_params_append {
31 	void *key;
32 	size_t keysize;
33 	void *val;
34 	size_t valsize;
35 };
36 
37 /* Version 2 */
38 /*
39  * The Version 2 protocol separates the SMMSTORE into 64KiB blocks, each
40  * of which can be read/written/cleared in an independent manner. The
41  * data format isn't specified. See documentation page for more details.
42  */
43 
44 #define SMM_BLOCK_SIZE (64 * KiB)
45 
46 /*
47  * Sets the communication buffer to use for read and write operations.
48  */
49 struct smmstore_params_init {
50 	uint32_t com_buffer;
51 	uint32_t com_buffer_size;
52 } __packed;
53 
54 /*
55  * Returns the number of blocks the SMMSTORE supports and their size.
56  * For edk2 this should be at least two blocks with 64 KiB each.
57  * The mmap_addr is set the memory mapped physical address of the SMMSTORE.
58  */
59 struct smmstore_params_info {
60 	uint32_t num_blocks;
61 	uint32_t block_size;
62 	uint32_t mmap_addr;
63 } __packed;
64 
65 /*
66  * Reads a chunk of raw data with size @bufsize from the block specified by
67  * @block_id starting at @bufoffset.
68  * The read data is placed in memory pointed to by @buf.
69  *
70  * @block_id must be less than num_blocks
71  * @bufoffset + @bufsize must be less than block_size
72  */
73 struct smmstore_params_raw_write {
74 	uint32_t bufsize;
75 	uint32_t bufoffset;
76 	uint32_t block_id;
77 } __packed;
78 
79 /*
80  * Writes a chunk of raw data with size @bufsize to the block specified by
81  * @block_id starting at @bufoffset.
82  *
83  * @block_id must be less than num_blocks
84  * @bufoffset + @bufsize must be less than block_size
85  */
86 struct smmstore_params_raw_read {
87 	uint32_t bufsize;
88 	uint32_t bufoffset;
89 	uint32_t block_id;
90 } __packed;
91 
92 /*
93  * Erases the specified block.
94  *
95  * @block_id must be less than num_blocks
96  */
97 struct smmstore_params_raw_clear {
98 	uint32_t block_id;
99 } __packed;
100 
101 
102 /* SMM handler */
103 uint32_t smmstore_exec(uint8_t command, void *param);
104 
105 /* Implementation of Version 1 */
106 int smmstore_read_region(void *buf, ssize_t *bufsize);
107 int smmstore_append_data(void *key, uint32_t key_sz, void *value, uint32_t value_sz);
108 int smmstore_clear_region(void);
109 
110 /* Implementation of Version 2 */
111 int smmstore_init(void *buf, size_t len);
112 int smmstore_rawread_region(uint32_t block_id, uint32_t offset, uint32_t bufsize);
113 int smmstore_rawwrite_region(uint32_t block_id, uint32_t offset, uint32_t bufsize);
114 int smmstore_rawclear_region(uint32_t block_id);
115 #if ENV_RAMSTAGE
116 int smmstore_get_info(struct smmstore_params_info *info);
117 #endif
118 struct region_device;
119 int smmstore_lookup_region(struct region_device *rstore);
120 
121 /* Advertise SMMSTORE v2 support */
122 struct lb_header;
123 void lb_smmstorev2(struct lb_header *header);
124 
125 #endif
126