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>
diff --git a/lib/crc32.c b/lib/crc32.c
index 996115d..bf03922 100644
--- a/lib/crc32.c
+++ b/lib/crc32.c
@@ -23,13 +23,10 @@
/* see: Documentation/crc32.txt for a description of algorithms */
#include <linux/crc32.h>
-#include <linux/kernel.h>
#include <linux/module.h>
-#include <linux/compiler.h>
#include <linux/types.h>
-#include <linux/init.h>
-#include <linux/atomic.h>
#include "crc32defs.h"
+
#if CRC_LE_BITS == 8
# define tole(x) __constant_cpu_to_le32(x)
#else
@@ -41,6 +38,7 @@
#else
# define tobe(x) (x)
#endif
+
#include "crc32table.h"
MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>");
@@ -96,6 +94,7 @@
#undef DO_CRC4
}
#endif
+
/**
* crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
* @crc: seed value for computation. ~0 for Ethernet, sometimes 0 for
@@ -103,53 +102,39 @@
* @p: pointer to buffer over which CRC is run
* @len: length of buffer @p
*/
-u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len);
-
-#if CRC_LE_BITS == 1
-/*
- * In fact, the table-based code will work in this case, but it can be
- * simplified by inlining the table in ?: form.
- */
-
u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
{
+#if CRC_LE_BITS == 1
int i;
while (len--) {
crc ^= *p++;
for (i = 0; i < 8; i++)
crc = (crc >> 1) ^ ((crc & 1) ? CRCPOLY_LE : 0);
}
- return crc;
-}
-#else /* Table-based approach */
-
-u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
-{
-# if CRC_LE_BITS == 8
+# elif CRC_LE_BITS == 2
+ while (len--) {
+ crc ^= *p++;
+ crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
+ crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
+ crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
+ crc = (crc >> 2) ^ crc32table_le[0][crc & 3];
+ }
+# elif CRC_LE_BITS == 4
+ while (len--) {
+ crc ^= *p++;
+ crc = (crc >> 4) ^ crc32table_le[0][crc & 15];
+ crc = (crc >> 4) ^ crc32table_le[0][crc & 15];
+ }
+# elif CRC_LE_BITS == 8
const u32 (*tab)[] = crc32table_le;
crc = __cpu_to_le32(crc);
crc = crc32_body(crc, p, len, tab);
- return __le32_to_cpu(crc);
-# elif CRC_LE_BITS == 4
- while (len--) {
- crc ^= *p++;
- crc = (crc >> 4) ^ crc32table_le[crc & 15];
- crc = (crc >> 4) ^ crc32table_le[crc & 15];
- }
- return crc;
-# elif CRC_LE_BITS == 2
- while (len--) {
- crc ^= *p++;
- crc = (crc >> 2) ^ crc32table_le[crc & 3];
- crc = (crc >> 2) ^ crc32table_le[crc & 3];
- crc = (crc >> 2) ^ crc32table_le[crc & 3];
- crc = (crc >> 2) ^ crc32table_le[crc & 3];
- }
- return crc;
-# endif
-}
+ crc = __le32_to_cpu(crc);
#endif
+ return crc;
+}
+EXPORT_SYMBOL(crc32_le);
/**
* crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
@@ -158,16 +143,9 @@
* @p: pointer to buffer over which CRC is run
* @len: length of buffer @p
*/
-u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len);
-
-#if CRC_BE_BITS == 1
-/*
- * In fact, the table-based code will work in this case, but it can be
- * simplified by inlining the table in ?: form.
- */
-
u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
{
+#if CRC_BE_BITS == 1
int i;
while (len--) {
crc ^= *p++ << 24;
@@ -176,39 +154,29 @@
(crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE :
0);
}
- return crc;
-}
-
-#else /* Table-based approach */
-u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
-{
-# if CRC_BE_BITS == 8
+# elif CRC_BE_BITS == 2
+ while (len--) {
+ crc ^= *p++ << 24;
+ crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
+ crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
+ crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
+ crc = (crc << 2) ^ crc32table_be[0][crc >> 30];
+ }
+# elif CRC_BE_BITS == 4
+ while (len--) {
+ crc ^= *p++ << 24;
+ crc = (crc << 4) ^ crc32table_be[0][crc >> 28];
+ crc = (crc << 4) ^ crc32table_be[0][crc >> 28];
+ }
+# elif CRC_BE_BITS == 8
const u32 (*tab)[] = crc32table_be;
crc = __cpu_to_be32(crc);
crc = crc32_body(crc, p, len, tab);
- return __be32_to_cpu(crc);
-# elif CRC_BE_BITS == 4
- while (len--) {
- crc ^= *p++ << 24;
- crc = (crc << 4) ^ crc32table_be[crc >> 28];
- crc = (crc << 4) ^ crc32table_be[crc >> 28];
- }
- return crc;
-# elif CRC_BE_BITS == 2
- while (len--) {
- crc ^= *p++ << 24;
- crc = (crc << 2) ^ crc32table_be[crc >> 30];
- crc = (crc << 2) ^ crc32table_be[crc >> 30];
- crc = (crc << 2) ^ crc32table_be[crc >> 30];
- crc = (crc << 2) ^ crc32table_be[crc >> 30];
- }
- return crc;
+ crc = __be32_to_cpu(crc);
# endif
+ return crc;
}
-#endif
-
-EXPORT_SYMBOL(crc32_le);
EXPORT_SYMBOL(crc32_be);
#ifdef CONFIG_CRC32_SELFTEST