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lfs_util.h
1 /*
2  * lfs utility functions
3  *
4  * Copyright (c) 2017, Arm Limited. All rights reserved.
5  * SPDX-License-Identifier: BSD-3-Clause
6  */
7 #ifndef LFS_UTIL_H
8 #define LFS_UTIL_H
9 
10 // Users can override lfs_util.h with their own configuration by defining
11 // LFS_CONFIG as a header file to include (-DLFS_CONFIG=lfs_config.h).
12 //
13 // If LFS_CONFIG is used, none of the default utils will be emitted and must be
14 // provided by the config file. To start I would suggest copying lfs_util.h and
15 // modifying as needed.
16 #ifdef LFS_CONFIG
17 #define LFS_STRINGIZE(x) LFS_STRINGIZE2(x)
18 #define LFS_STRINGIZE2(x) #x
19 #include LFS_STRINGIZE(LFS_CONFIG)
20 #else
21 
22 // System includes
23 #include <stdint.h>
24 #include <stdbool.h>
25 #include <string.h>
26 
27 #ifndef LFS_NO_MALLOC
28 #include <stdlib.h>
29 #endif
30 #ifndef LFS_NO_ASSERT
31 #include <assert.h>
32 #endif
33 #if !defined(LFS_NO_INFO) || !defined(LFS_NO_DEBUG) || !defined(LFS_NO_WARN) || !defined(LFS_NO_ERROR)
34 #include <stdio.h>
35 #endif
36 
37 #ifdef __cplusplus
38 extern "C"
39 {
40 #endif
41 
42 
43 // Macros, may be replaced by system specific wrappers. Arguments to these
44 // macros must not have side-effects as the macros can be removed for a smaller
45 // code footprint
46 
47 #ifdef __MBED__
48 #include "mbed_debug.h"
49 #include "mbed_assert.h"
50 #else
51 #define MBED_LFS_ENABLE_INFO false
52 #define MBED_LFS_ENABLE_DEBUG true
53 #define MBED_LFS_ENABLE_WARN true
54 #define MBED_LFS_ENABLE_ERROR true
55 #define MBED_LFS_ENABLE_ASSERT true
56 #define MBED_LFS_INTRINSICS true
57 #endif
58 
59 // Logging functions
60 #if !defined(LFS_NO_INFO) && MBED_LFS_ENABLE_INFO
61 #define LFS_INFO(fmt, ...) printf("lfs info:%d: " fmt "\n", __LINE__, __VA_ARGS__)
62 #elif !defined(LFS_NO_INFO) && !defined(MBED_LFS_ENABLE_INFO)
63 #define LFS_INFO(fmt, ...) debug("lfs info:%d: " fmt "\n", __LINE__, __VA_ARGS__)
64 #else
65 #define LFS_INFO(fmt, ...)
66 #endif
67 
68 #if !defined(LFS_NO_DEBUG) && MBED_LFS_ENABLE_DEBUG
69 #define LFS_DEBUG(fmt, ...) printf("lfs debug:%d: " fmt "\n", __LINE__, __VA_ARGS__)
70 #elif !defined(LFS_NO_DEBUG) && !defined(MBED_LFS_ENABLE_DEBUG)
71 #define LFS_DEBUG(fmt, ...) debug("lfs debug:%d: " fmt "\n", __LINE__, __VA_ARGS__)
72 #else
73 #define LFS_DEBUG(fmt, ...)
74 #endif
75 
76 #if !defined(LFS_NO_WARN) && MBED_LFS_ENABLE_WARN
77 #define LFS_WARN(fmt, ...) printf("lfs warn:%d: " fmt "\n", __LINE__, __VA_ARGS__)
78 #elif !defined(LFS_NO_WARN) && !defined(MBED_LFS_ENABLE_WARN)
79 #define LFS_WARN(fmt, ...) debug("lfs warn:%d: " fmt "\n", __LINE__, __VA_ARGS__)
80 #else
81 #define LFS_WARN(fmt, ...)
82 #endif
83 
84 #if !defined(LFS_NO_ERROR) && MBED_LFS_ENABLE_ERROR
85 #define LFS_ERROR(fmt, ...) printf("lfs error:%d: " fmt "\n", __LINE__, __VA_ARGS__)
86 #elif !defined(LFS_NO_ERROR) && !defined(MBED_LFS_ENABLE_ERROR)
87 #define LFS_ERROR(fmt, ...) debug("lfs error:%d: " fmt "\n", __LINE__, __VA_ARGS__)
88 #else
89 #define LFS_ERROR(fmt, ...)
90 #endif
91 
92 // Runtime assertions
93 #if !defined(LFS_NO_ASSERT) && MBED_LFS_ENABLE_ASSERT
94 #define LFS_ASSERT(test) assert(test)
95 #elif !defined(LFS_NO_ASSERT) && !defined(MBED_LFS_ENABLE_ASSERT)
96 #define LFS_ASSERT(test) MBED_ASSERT(test)
97 #else
98 #define LFS_ASSERT(test)
99 #endif
100 
101 
102 // Builtin functions, these may be replaced by more efficient
103 // toolchain-specific implementations. LFS_NO_INTRINSICS falls back to a more
104 // expensive basic C implementation for debugging purposes
105 
106 // Min/max functions for unsigned 32-bit numbers
107 static inline uint32_t lfs_max(uint32_t a, uint32_t b) {
108  return (a > b) ? a : b;
109 }
110 
111 static inline uint32_t lfs_min(uint32_t a, uint32_t b) {
112  return (a < b) ? a : b;
113 }
114 
115 // Find the next smallest power of 2 less than or equal to a
116 static inline uint32_t lfs_npw2(uint32_t a) {
117 #if !defined(LFS_NO_INTRINSICS) && MBED_LFS_INTRINSICS && \
118  (defined(__GNUC__) || defined(__CC_ARM))
119  return 32 - __builtin_clz(a-1);
120 #else
121  uint32_t r = 0;
122  uint32_t s;
123  a -= 1;
124  s = (a > 0xffff) << 4; a >>= s; r |= s;
125  s = (a > 0xff ) << 3; a >>= s; r |= s;
126  s = (a > 0xf ) << 2; a >>= s; r |= s;
127  s = (a > 0x3 ) << 1; a >>= s; r |= s;
128  return (r | (a >> 1)) + 1;
129 #endif
130 }
131 
132 // Count the number of trailing binary zeros in a
133 // lfs_ctz(0) may be undefined
134 static inline uint32_t lfs_ctz(uint32_t a) {
135 #if !defined(LFS_NO_INTRINSICS) && MBED_LFS_INTRINSICS && \
136  defined(__GNUC__)
137  return __builtin_ctz(a);
138 #else
139  return lfs_npw2((a & -a) + 1) - 1;
140 #endif
141 }
142 
143 // Count the number of binary ones in a
144 static inline uint32_t lfs_popc(uint32_t a) {
145 #if !defined(LFS_NO_INTRINSICS) && MBED_LFS_INTRINSICS && \
146  (defined(__GNUC__) || defined(__CC_ARM))
147  return __builtin_popcount(a);
148 #else
149  a = a - ((a >> 1) & 0x55555555);
150  a = (a & 0x33333333) + ((a >> 2) & 0x33333333);
151  return (((a + (a >> 4)) & 0xf0f0f0f) * 0x1010101) >> 24;
152 #endif
153 }
154 
155 // Find the sequence comparison of a and b, this is the distance
156 // between a and b ignoring overflow
157 static inline int lfs_scmp(uint32_t a, uint32_t b) {
158  return (int)(unsigned)(a - b);
159 }
160 
161 // Convert from 32-bit little-endian to native order
162 static inline uint32_t lfs_fromle32(uint32_t a) {
163 #if !defined(LFS_NO_INTRINSICS) && MBED_LFS_INTRINSICS && ( \
164  (defined( BYTE_ORDER ) && BYTE_ORDER == ORDER_LITTLE_ENDIAN ) || \
165  (defined(__BYTE_ORDER ) && __BYTE_ORDER == __ORDER_LITTLE_ENDIAN ) || \
166  (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
167  return a;
168 #elif !defined(LFS_NO_INTRINSICS) && MBED_LFS_INTRINSICS && ( \
169  (defined( BYTE_ORDER ) && BYTE_ORDER == ORDER_BIG_ENDIAN ) || \
170  (defined(__BYTE_ORDER ) && __BYTE_ORDER == __ORDER_BIG_ENDIAN ) || \
171  (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
172  return __builtin_bswap32(a);
173 #else
174  return (((uint8_t*)&a)[0] << 0) |
175  (((uint8_t*)&a)[1] << 8) |
176  (((uint8_t*)&a)[2] << 16) |
177  (((uint8_t*)&a)[3] << 24);
178 #endif
179 }
180 
181 // Convert to 32-bit little-endian from native order
182 static inline uint32_t lfs_tole32(uint32_t a) {
183  return lfs_fromle32(a);
184 }
185 
186 // Calculate CRC-32 with polynomial = 0x04c11db7
187 void lfs_crc(uint32_t *crc, const void *buffer, size_t size);
188 
189 // Allocate memory, only used if buffers are not provided to littlefs
190 static inline void *lfs_malloc(size_t size) {
191 #ifndef LFS_NO_MALLOC
192  return malloc(size);
193 #else
194  (void)size;
195  return NULL;
196 #endif
197 }
198 
199 // Deallocate memory, only used if buffers are not provided to littlefs
200 static inline void lfs_free(void *p) {
201 #ifndef LFS_NO_MALLOC
202  free(p);
203 #else
204  (void)p;
205 #endif
206 }
207 
208 
209 #ifdef __cplusplus
210 } /* extern "C" */
211 #endif
212 
213 #endif
214 #endif
lfs_free
Definition: lfs.h:262
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