aboutsummaryrefslogtreecommitdiffstats
path: root/lib
diff options
context:
space:
mode:
Diffstat (limited to 'lib')
-rw-r--r--lib/crc32.c24
-rw-r--r--lib/gen_crc32table.c47
2 files changed, 47 insertions, 24 deletions
diff --git a/lib/crc32.c b/lib/crc32.c
index bc5b936e9142..4855995fcde9 100644
--- a/lib/crc32.c
+++ b/lib/crc32.c
@@ -48,12 +48,20 @@ MODULE_LICENSE("GPL");
48#if CRC_LE_BITS == 8 || CRC_BE_BITS == 8 48#if CRC_LE_BITS == 8 || CRC_BE_BITS == 8
49 49
50static inline u32 50static inline u32
51crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 *tab) 51crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256])
52{ 52{
53# ifdef __LITTLE_ENDIAN 53# ifdef __LITTLE_ENDIAN
54# define DO_CRC(x) crc = tab[(crc ^ (x)) & 255 ] ^ (crc >> 8) 54# define DO_CRC(x) crc = tab[0][(crc ^ (x)) & 255] ^ (crc >> 8)
55# define DO_CRC4 crc = tab[3][(crc) & 255] ^ \
56 tab[2][(crc >> 8) & 255] ^ \
57 tab[1][(crc >> 16) & 255] ^ \
58 tab[0][(crc >> 24) & 255]
55# else 59# else
56# define DO_CRC(x) crc = tab[((crc >> 24) ^ (x)) & 255] ^ (crc << 8) 60# define DO_CRC(x) crc = tab[0][((crc >> 24) ^ (x)) & 255] ^ (crc << 8)
61# define DO_CRC4 crc = tab[0][(crc) & 255] ^ \
62 tab[1][(crc >> 8) & 255] ^ \
63 tab[2][(crc >> 16) & 255] ^ \
64 tab[3][(crc >> 24) & 255]
57# endif 65# endif
58 const u32 *b; 66 const u32 *b;
59 size_t rem_len; 67 size_t rem_len;
@@ -70,10 +78,7 @@ crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 *tab)
70 b = (const u32 *)buf; 78 b = (const u32 *)buf;
71 for (--b; len; --len) { 79 for (--b; len; --len) {
72 crc ^= *++b; /* use pre increment for speed */ 80 crc ^= *++b; /* use pre increment for speed */
73 DO_CRC(0); 81 DO_CRC4;
74 DO_CRC(0);
75 DO_CRC(0);
76 DO_CRC(0);
77 } 82 }
78 len = rem_len; 83 len = rem_len;
79 /* And the last few bytes */ 84 /* And the last few bytes */
@@ -85,6 +90,7 @@ crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 *tab)
85 } 90 }
86 return crc; 91 return crc;
87#undef DO_CRC 92#undef DO_CRC
93#undef DO_CRC4
88} 94}
89#endif 95#endif
90/** 96/**
@@ -117,7 +123,7 @@ u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
117u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len) 123u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
118{ 124{
119# if CRC_LE_BITS == 8 125# if CRC_LE_BITS == 8
120 const u32 *tab = crc32table_le; 126 const u32 (*tab)[] = crc32table_le;
121 127
122 crc = __cpu_to_le32(crc); 128 crc = __cpu_to_le32(crc);
123 crc = crc32_body(crc, p, len, tab); 129 crc = crc32_body(crc, p, len, tab);
@@ -174,7 +180,7 @@ u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
174u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len) 180u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
175{ 181{
176# if CRC_BE_BITS == 8 182# if CRC_BE_BITS == 8
177 const u32 *tab = crc32table_be; 183 const u32 (*tab)[] = crc32table_be;
178 184
179 crc = __cpu_to_be32(crc); 185 crc = __cpu_to_be32(crc);
180 crc = crc32_body(crc, p, len, tab); 186 crc = crc32_body(crc, p, len, tab);
diff --git a/lib/gen_crc32table.c b/lib/gen_crc32table.c
index bea5d97df991..85d0e412a04f 100644
--- a/lib/gen_crc32table.c
+++ b/lib/gen_crc32table.c
@@ -7,8 +7,8 @@
7#define LE_TABLE_SIZE (1 << CRC_LE_BITS) 7#define LE_TABLE_SIZE (1 << CRC_LE_BITS)
8#define BE_TABLE_SIZE (1 << CRC_BE_BITS) 8#define BE_TABLE_SIZE (1 << CRC_BE_BITS)
9 9
10static uint32_t crc32table_le[LE_TABLE_SIZE]; 10static uint32_t crc32table_le[4][LE_TABLE_SIZE];
11static uint32_t crc32table_be[BE_TABLE_SIZE]; 11static uint32_t crc32table_be[4][BE_TABLE_SIZE];
12 12
13/** 13/**
14 * crc32init_le() - allocate and initialize LE table data 14 * crc32init_le() - allocate and initialize LE table data
@@ -22,12 +22,19 @@ static void crc32init_le(void)
22 unsigned i, j; 22 unsigned i, j;
23 uint32_t crc = 1; 23 uint32_t crc = 1;
24 24
25 crc32table_le[0] = 0; 25 crc32table_le[0][0] = 0;
26 26
27 for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) { 27 for (i = 1 << (CRC_LE_BITS - 1); i; i >>= 1) {
28 crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0); 28 crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
29 for (j = 0; j < LE_TABLE_SIZE; j += 2 * i) 29 for (j = 0; j < LE_TABLE_SIZE; j += 2 * i)
30 crc32table_le[i + j] = crc ^ crc32table_le[j]; 30 crc32table_le[0][i + j] = crc ^ crc32table_le[0][j];
31 }
32 for (i = 0; i < LE_TABLE_SIZE; i++) {
33 crc = crc32table_le[0][i];
34 for (j = 1; j < 4; j++) {
35 crc = crc32table_le[0][crc & 0xff] ^ (crc >> 8);
36 crc32table_le[j][i] = crc;
37 }
31 } 38 }
32} 39}
33 40
@@ -39,25 +46,35 @@ static void crc32init_be(void)
39 unsigned i, j; 46 unsigned i, j;
40 uint32_t crc = 0x80000000; 47 uint32_t crc = 0x80000000;
41 48
42 crc32table_be[0] = 0; 49 crc32table_be[0][0] = 0;
43 50
44 for (i = 1; i < BE_TABLE_SIZE; i <<= 1) { 51 for (i = 1; i < BE_TABLE_SIZE; i <<= 1) {
45 crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0); 52 crc = (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 0);
46 for (j = 0; j < i; j++) 53 for (j = 0; j < i; j++)
47 crc32table_be[i + j] = crc ^ crc32table_be[j]; 54 crc32table_be[0][i + j] = crc ^ crc32table_be[0][j];
55 }
56 for (i = 0; i < BE_TABLE_SIZE; i++) {
57 crc = crc32table_be[0][i];
58 for (j = 1; j < 4; j++) {
59 crc = crc32table_be[0][(crc >> 24) & 0xff] ^ (crc << 8);
60 crc32table_be[j][i] = crc;
61 }
48 } 62 }
49} 63}
50 64
51static void output_table(uint32_t table[], int len, char *trans) 65static void output_table(uint32_t table[4][256], int len, char *trans)
52{ 66{
53 int i; 67 int i, j;
54 68
55 for (i = 0; i < len - 1; i++) { 69 for (j = 0 ; j < 4; j++) {
56 if (i % ENTRIES_PER_LINE == 0) 70 printf("{");
57 printf("\n"); 71 for (i = 0; i < len - 1; i++) {
58 printf("%s(0x%8.8xL), ", trans, table[i]); 72 if (i % ENTRIES_PER_LINE == 0)
73 printf("\n");
74 printf("%s(0x%8.8xL), ", trans, table[j][i]);
75 }
76 printf("%s(0x%8.8xL)},\n", trans, table[j][len - 1]);
59 } 77 }
60 printf("%s(0x%8.8xL)\n", trans, table[len - 1]);
61} 78}
62 79
63int main(int argc, char** argv) 80int main(int argc, char** argv)
@@ -66,14 +83,14 @@ int main(int argc, char** argv)
66 83
67 if (CRC_LE_BITS > 1) { 84 if (CRC_LE_BITS > 1) {
68 crc32init_le(); 85 crc32init_le();
69 printf("static const u32 crc32table_le[] = {"); 86 printf("static const u32 crc32table_le[4][256] = {");
70 output_table(crc32table_le, LE_TABLE_SIZE, "tole"); 87 output_table(crc32table_le, LE_TABLE_SIZE, "tole");
71 printf("};\n"); 88 printf("};\n");
72 } 89 }
73 90
74 if (CRC_BE_BITS > 1) { 91 if (CRC_BE_BITS > 1) {
75 crc32init_be(); 92 crc32init_be();
76 printf("static const u32 crc32table_be[] = {"); 93 printf("static const u32 crc32table_be[4][256] = {");
77 output_table(crc32table_be, BE_TABLE_SIZE, "tobe"); 94 output_table(crc32table_be, BE_TABLE_SIZE, "tobe");
78 printf("};\n"); 95 printf("};\n");
79 } 96 }