crc32: bolt on crc32c
Reuse the existing crc32 code to stamp out a crc32c implementation.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Bob Pearson <rpearson@systemfabricworks.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
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 a1a5145..87678dd 100644
--- a/lib/crc32.c
+++ b/lib/crc32.c
@@ -46,7 +46,7 @@
#include "crc32table.h"
MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>");
-MODULE_DESCRIPTION("Ethernet CRC32 calculations");
+MODULE_DESCRIPTION("Various CRC32 calculations");
MODULE_LICENSE("GPL");
#if CRC_LE_BITS > 8 || CRC_BE_BITS > 8
@@ -135,45 +135,66 @@
* @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)
+static inline u32 __pure crc32_le_generic(u32 crc, unsigned char const *p,
+ size_t len, const u32 (*tab)[256],
+ u32 polynomial)
{
#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);
+ crc = (crc >> 1) ^ ((crc & 1) ? polynomial : 0);
}
# 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];
+ crc = (crc >> 2) ^ tab[0][crc & 3];
+ crc = (crc >> 2) ^ tab[0][crc & 3];
+ crc = (crc >> 2) ^ tab[0][crc & 3];
+ crc = (crc >> 2) ^ tab[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];
+ crc = (crc >> 4) ^ tab[0][crc & 15];
+ crc = (crc >> 4) ^ tab[0][crc & 15];
}
# elif CRC_LE_BITS == 8
/* aka Sarwate algorithm */
while (len--) {
crc ^= *p++;
- crc = (crc >> 8) ^ crc32table_le[0][crc & 255];
+ crc = (crc >> 8) ^ tab[0][crc & 255];
}
# else
- const u32 (*tab)[] = crc32table_le;
-
crc = (__force u32) __cpu_to_le32(crc);
crc = crc32_body(crc, p, len, tab);
crc = __le32_to_cpu((__force __le32)crc);
#endif
return crc;
}
+
+#if CRC_LE_BITS == 1
+u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+ return crc32_le_generic(crc, p, len, NULL, CRCPOLY_LE);
+}
+u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len)
+{
+ return crc32_le_generic(crc, p, len, NULL, CRC32C_POLY_LE);
+}
+#else
+u32 __pure crc32_le(u32 crc, unsigned char const *p, size_t len)
+{
+ return crc32_le_generic(crc, p, len, crc32table_le, CRCPOLY_LE);
+}
+u32 __pure __crc32c_le(u32 crc, unsigned char const *p, size_t len)
+{
+ return crc32_le_generic(crc, p, len, crc32ctable_le, CRC32C_POLY_LE);
+}
+#endif
EXPORT_SYMBOL(crc32_le);
+EXPORT_SYMBOL(__crc32c_le);
/**
* crc32_be() - Calculate bitwise big-endian Ethernet AUTODIN II CRC32
@@ -182,7 +203,9 @@
* @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)
+static inline u32 __pure crc32_be_generic(u32 crc, unsigned char const *p,
+ size_t len, const u32 (*tab)[256],
+ u32 polynomial)
{
#if CRC_BE_BITS == 1
int i;
@@ -190,37 +213,47 @@
crc ^= *p++ << 24;
for (i = 0; i < 8; i++)
crc =
- (crc << 1) ^ ((crc & 0x80000000) ? CRCPOLY_BE :
+ (crc << 1) ^ ((crc & 0x80000000) ? polynomial :
0);
}
# 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];
+ crc = (crc << 2) ^ tab[0][crc >> 30];
+ crc = (crc << 2) ^ tab[0][crc >> 30];
+ crc = (crc << 2) ^ tab[0][crc >> 30];
+ crc = (crc << 2) ^ tab[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];
+ crc = (crc << 4) ^ tab[0][crc >> 28];
+ crc = (crc << 4) ^ tab[0][crc >> 28];
}
# elif CRC_BE_BITS == 8
while (len--) {
crc ^= *p++ << 24;
- crc = (crc << 8) ^ crc32table_be[0][crc >> 24];
+ crc = (crc << 8) ^ tab[0][crc >> 24];
}
# else
- const u32 (*tab)[] = crc32table_be;
-
crc = (__force u32) __cpu_to_be32(crc);
crc = crc32_body(crc, p, len, tab);
crc = __be32_to_cpu((__force __be32)crc);
# endif
return crc;
}
+
+#if CRC_LE_BITS == 1
+u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+ return crc32_be_generic(crc, p, len, NULL, CRCPOLY_BE);
+}
+#else
+u32 __pure crc32_be(u32 crc, unsigned char const *p, size_t len)
+{
+ return crc32_be_generic(crc, p, len, crc32table_be, CRCPOLY_BE);
+}
+#endif
EXPORT_SYMBOL(crc32_be);
#ifdef CONFIG_CRC32_SELFTEST