1 /*
2  * Testing block device, wraps filebd and rambd while providing a bunch
3  * of hooks for testing littlefs in various conditions.
4  *
5  * Copyright (c) 2017, Arm Limited. All rights reserved.
6  * SPDX-License-Identifier: BSD-3-Clause
7  */
8 #ifndef LFS_TESTBD_H
9 #define LFS_TESTBD_H
10 
11 #include "lfs.h"
12 #include "lfs_util.h"
13 #include "bd/lfs_rambd.h"
14 #include "bd/lfs_filebd.h"
15 
16 #ifdef __cplusplus
17 extern "C"
18 {
19 #endif
20 
21 
22 // Block device specific tracing
23 #ifdef LFS_TESTBD_YES_TRACE
24 #define LFS_TESTBD_TRACE(...) LFS_TRACE(__VA_ARGS__)
25 #else
26 #define LFS_TESTBD_TRACE(...)
27 #endif
28 
29 // Mode determining how "bad blocks" behave during testing. This simulates
30 // some real-world circumstances such as progs not sticking (prog-noop),
31 // a readonly disk (erase-noop), and ECC failures (read-error).
32 //
33 // Not that read-noop is not allowed. Read _must_ return a consistent (but
34 // may be arbitrary) value on every read.
35 enum lfs_testbd_badblock_behavior {
36     LFS_TESTBD_BADBLOCK_PROGERROR,
37     LFS_TESTBD_BADBLOCK_ERASEERROR,
38     LFS_TESTBD_BADBLOCK_READERROR,
39     LFS_TESTBD_BADBLOCK_PROGNOOP,
40     LFS_TESTBD_BADBLOCK_ERASENOOP,
41 };
42 
43 // Type for measuring wear
44 typedef uint32_t lfs_testbd_wear_t;
45 typedef int32_t  lfs_testbd_swear_t;
46 
47 // testbd config, this is required for testing
48 struct lfs_testbd_config {
49     // 8-bit erase value to use for simulating erases. -1 does not simulate
50     // erases, which can speed up testing by avoiding all the extra block-device
51     // operations to store the erase value.
52     int32_t erase_value;
53 
54     // Number of erase cycles before a block becomes "bad". The exact behavior
55     // of bad blocks is controlled by the badblock_mode.
56     uint32_t erase_cycles;
57 
58     // The mode determining how bad blocks fail
59     uint8_t badblock_behavior;
60 
61     // Number of write operations (erase/prog) before forcefully killing
62     // the program with exit. Simulates power-loss. 0 disables.
63     uint32_t power_cycles;
64 
65     // Optional buffer for RAM block device.
66     void *buffer;
67 
68     // Optional buffer for wear
69     void *wear_buffer;
70 };
71 
72 // testbd state
73 typedef struct lfs_testbd {
74     union {
75         struct {
76             lfs_filebd_t bd;
77             struct lfs_filebd_config cfg;
78         } file;
79         struct {
80             lfs_rambd_t bd;
81             struct lfs_rambd_config cfg;
82         } ram;
83     } u;
84 
85     bool persist;
86     uint32_t power_cycles;
87     lfs_testbd_wear_t *wear;
88 
89     const struct lfs_testbd_config *cfg;
90 } lfs_testbd_t;
91 
92 
93 /// Block device API ///
94 
95 // Create a test block device using the geometry in lfs_config
96 //
97 // Note that filebd is used if a path is provided, if path is NULL
98 // testbd will use rambd which can be much faster.
99 int lfs_testbd_create(const struct lfs_config *cfg, const char *path);
100 int lfs_testbd_createcfg(const struct lfs_config *cfg, const char *path,
101         const struct lfs_testbd_config *bdcfg);
102 
103 // Clean up memory associated with block device
104 int lfs_testbd_destroy(const struct lfs_config *cfg);
105 
106 // Read a block
107 int lfs_testbd_read(const struct lfs_config *cfg, lfs_block_t block,
108         lfs_off_t off, void *buffer, lfs_size_t size);
109 
110 // Program a block
111 //
112 // The block must have previously been erased.
113 int lfs_testbd_prog(const struct lfs_config *cfg, lfs_block_t block,
114         lfs_off_t off, const void *buffer, lfs_size_t size);
115 
116 // Erase a block
117 //
118 // A block must be erased before being programmed. The
119 // state of an erased block is undefined.
120 int lfs_testbd_erase(const struct lfs_config *cfg, lfs_block_t block);
121 
122 // Sync the block device
123 int lfs_testbd_sync(const struct lfs_config *cfg);
124 
125 
126 /// Additional extended API for driving test features ///
127 
128 // Get simulated wear on a given block
129 lfs_testbd_swear_t lfs_testbd_getwear(const struct lfs_config *cfg,
130         lfs_block_t block);
131 
132 // Manually set simulated wear on a given block
133 int lfs_testbd_setwear(const struct lfs_config *cfg,
134         lfs_block_t block, lfs_testbd_wear_t wear);
135 
136 
137 #ifdef __cplusplus
138 } /* extern "C" */
139 #endif
140 
141 #endif
142