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authorBob Pearson <rpearson@systemfabricworks.com>2012-03-23 18:02:22 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-23 19:58:37 -0400
commit60e58d5c9d8d698600e8ccb44b5a13cf99d0d90f (patch)
tree81912b32deaf6edf23a00f0f92f82efa95f6af52 /lib
parent3863ef31dcf04f977a94402348fec06179db58e0 (diff)
crc32: miscellaneous cleanups
Misc cleanup of lib/crc32.c and related files. - remove unnecessary header files. - straighten out some convoluted ifdef's - rewrite some references to 2 dimensional arrays as 1 dimensional arrays to make them correct. I.e. replace tab[i] with tab[0][i]. - a few trivial whitespace changes - fix a warning in gen_crc32tables.c caused by a mismatch in the type of the pointer passed to output table. Since the table is only used at kernel compile time, it is simpler to make the table big enough to hold the largest column size used. One cannot make the column size smaller in output_table because it has to be used by both the le and be tables and they can have different column sizes. [djwong@us.ibm.com: Minor changelog tweaks] Signed-off-by: Bob Pearson <rpearson@systemfabricworks.com> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib')
-rw-r--r--lib/crc32.c104
-rw-r--r--lib/gen_crc32table.c6
2 files changed, 39 insertions, 71 deletions
diff --git a/lib/crc32.c b/lib/crc32.c
index 996115d4f377..bf03922c5d69 100644
--- a/lib/crc32.c
+++ b/lib/crc32.c
@@ -23,13 +23,10 @@
23/* see: Documentation/crc32.txt for a description of algorithms */ 23/* see: Documentation/crc32.txt for a description of algorithms */
24 24
25#include <linux/crc32.h> 25#include <linux/crc32.h>
26#include <linux/kernel.h>
27#include <linux/module.h> 26#include <linux/module.h>
28#include <linux/compiler.h>
29#include <linux/types.h> 27#include <linux/types.h>
30#include <linux/init.h>
31#include <linux/atomic.h>
32#include "crc32defs.h" 28#include "crc32defs.h"
29
33#if CRC_LE_BITS == 8 30#if CRC_LE_BITS == 8
34# define tole(x) __constant_cpu_to_le32(x) 31# define tole(x) __constant_cpu_to_le32(x)
35#else 32#else
@@ -41,6 +38,7 @@
41#else 38#else
42# define tobe(x) (x) 39# define tobe(x) (x)
43#endif 40#endif
41
44#include "crc32table.h" 42#include "crc32table.h"
45 43
46MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>"); 44MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>");
@@ -96,6 +94,7 @@ crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256])
96#undef DO_CRC4 94#undef DO_CRC4
97} 95}
98#endif 96#endif
97
99/** 98/**
100 * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32 99 * crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
101 * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for 100 * @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for
@@ -103,53 +102,39 @@ crc32_body(u32 crc, unsigned char const *buf, size_t len, const u32 (*tab)[256])
103 * @p: pointer to buffer over which CRC is run 102 * @p: pointer to buffer over which CRC is run
104 * @len: length of buffer @p 103 * @len: length of buffer @p
105 */ 104 */
106u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len);
107
108#if CRC_LE_BITS == 1
109/*
110 * In fact, the table-based code will work in this case, but it can be
111 * simplified by inlining the table in ?: form.
112 */
113
114u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len) 105u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
115{ 106{
107#if CRC_LE_BITS == 1
116 int i; 108 int i;
117 while (len--) { 109 while (len--) {
118 crc ^= *p++; 110 crc ^= *p++;
119 for (i = 0; i < 8; i++) 111 for (i = 0; i < 8; i++)
120 crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0); 112 crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
121 } 113 }
122 return crc; 114# elif CRC_LE_BITS == 2
123}
124#else /* Table-based approach */
125
126u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
127{
128# if CRC_LE_BITS == 8
129 const u32 (*tab)[] = crc32table_le;
130
131 crc = __cpu_to_le32(crc);
132 crc = crc32_body(crc, p, len, tab);
133 return __le32_to_cpu(crc);
134# elif CRC_LE_BITS == 4
135 while (len--) { 115 while (len--) {
136 crc ^= *p++; 116 crc ^= *p++;
137 crc = (crc >> 4) ^ crc32table_le[crc & 15]; 117 crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
138 crc = (crc >> 4) ^ crc32table_le[crc & 15]; 118 crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
119 crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
120 crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
139 } 121 }
140 return crc; 122# elif CRC_LE_BITS == 4
141# elif CRC_LE_BITS == 2
142 while (len--) { 123 while (len--) {
143 crc ^= *p++; 124 crc ^= *p++;
144 crc = (crc >> 2) ^ crc32table_le[crc & 3]; 125 crc = (crc >> 4) ^ crc32table_le[0][crc & 15];
145 crc = (crc >> 2) ^ crc32table_le[crc & 3]; 126 crc = (crc >> 4) ^ crc32table_le[0][crc & 15];
146 crc = (crc >> 2) ^ crc32table_le[crc & 3];
147 crc = (crc >> 2) ^ crc32table_le[crc & 3];
148 } 127 }
128# elif CRC_LE_BITS == 8
129 const u32 (*tab)[] = crc32table_le;
130
131 crc = __cpu_to_le32(crc);
132 crc = crc32_body(crc, p, len, tab);
133 crc = __le32_to_cpu(crc);
134#endif
149 return crc; 135 return crc;
150# endif
151} 136}
152#endif 137EXPORT_SYMBOL(crc32_le);
153 138
154/** 139/**
155 * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32 140 * crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
@@ -158,16 +143,9 @@ u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
158 * @p: pointer to buffer over which CRC is run 143 * @p: pointer to buffer over which CRC is run
159 * @len: length of buffer @p 144 * @len: length of buffer @p
160 */ 145 */
161u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len);
162
163#if CRC_BE_BITS == 1
164/*
165 * In fact, the table-based code will work in this case, but it can be
166 * simplified by inlining the table in ?: form.
167 */
168
169u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len) 146u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
170{ 147{
148#if CRC_BE_BITS == 1
171 int i; 149 int i;
172 while (len--) { 150 while (len--) {
173 crc ^= *p++ << 24; 151 crc ^= *p++ << 24;
@@ -176,39 +154,29 @@ u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
176 (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE : 154 (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE :
177 0); 155 0);
178 } 156 }
179 return crc; 157# elif CRC_BE_BITS == 2
180}
181
182#else /* Table-based approach */
183u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
184{
185# if CRC_BE_BITS == 8
186 const u32 (*tab)[] = crc32table_be;
187
188 crc = __cpu_to_be32(crc);
189 crc = crc32_body(crc, p, len, tab);
190 return __be32_to_cpu(crc);
191# elif CRC_BE_BITS == 4
192 while (len--) { 158 while (len--) {
193 crc ^= *p++ << 24; 159 crc ^= *p++ << 24;
194 crc = (crc << 4) ^ crc32table_be[crc >> 28]; 160 crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
195 crc = (crc << 4) ^ crc32table_be[crc >> 28]; 161 crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
162 crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
163 crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
196 } 164 }
197 return crc; 165# elif CRC_BE_BITS == 4
198# elif CRC_BE_BITS == 2
199 while (len--) { 166 while (len--) {
200 crc ^= *p++ << 24; 167 crc ^= *p++ << 24;
201 crc = (crc << 2) ^ crc32table_be[crc >> 30]; 168 crc = (crc << 4) ^ crc32table_be[0][crc >> 28];
202 crc = (crc << 2) ^ crc32table_be[crc >> 30]; 169 crc = (crc << 4) ^ crc32table_be[0][crc >> 28];
203 crc = (crc << 2) ^ crc32table_be[crc >> 30];
204 crc = (crc << 2) ^ crc32table_be[crc >> 30];
205 } 170 }
206 return crc; 171# elif CRC_BE_BITS == 8
172 const u32 (*tab)[] = crc32table_be;
173
174 crc = __cpu_to_be32(crc);
175 crc = crc32_body(crc, p, len, tab);
176 crc = __be32_to_cpu(crc);
207# endif 177# endif
178 return crc;
208} 179}
209#endif
210
211EXPORT_SYMBOL(crc32_le);
212EXPORT_SYMBOL(crc32_be); 180EXPORT_SYMBOL(crc32_be);
213 181
214#ifdef CONFIG_CRC32_SELFTEST 182#ifdef CONFIG_CRC32_SELFTEST
diff --git a/lib/gen_crc32table.c b/lib/gen_crc32table.c
index 85d0e412a04f..eced7696eb7c 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[4][LE_TABLE_SIZE]; 10static uint32_t crc32table_le[4][256];
11static uint32_t crc32table_be[4][BE_TABLE_SIZE]; 11static uint32_t crc32table_be[4][256];
12 12
13/** 13/**
14 * crc32init_le() - allocate and initialize LE table data 14 * crc32init_le() - allocate and initialize LE table data
@@ -62,7 +62,7 @@ static void crc32init_be(void)
62 } 62 }
63} 63}
64 64
65static void output_table(uint32_t table[4][256], int len, char *trans) 65static void output_table(uint32_t (*table)[256], int len, char *trans)
66{ 66{
67 int i, j; 67 int i, j;
68 68