[PATCH] crc32: replace bitreverse by bitrev32

This patch replaces bitreverse() by bitrev32.  The only users of bitreverse()
are crc32 itself and via-velocity.

Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

4 files changed, 9 insertions, 26 deletions

diff --git a/drivers/net/via-velocity.c b/drivers/net/via-velocity.c
index 74f894795a1b..4587f23f4e4b 100644
--- a/drivers/net/via-velocity.c
+++ b/drivers/net/via-velocity.c
@@ -3132,7 +3132,7 @@ static u16 wol_calc_crc(int size, u8 * pattern, u8 *mask_pattern)
         }
         /*      Finally, invert the result once to get the correct data */
         crc = ~crc;
-        return bitreverse(crc) >> 16;
+        return bitrev32(crc) >> 16;
 }
 
 /**
diff --git a/include/linux/crc32.h b/include/linux/crc32.h
index 56c0645789a9..e20dd1f9b40a 100644
--- a/include/linux/crc32.h
+++ b/include/linux/crc32.h
@@ -6,10 +6,10 @@
 #define _LINUX_CRC32_H
 
 #include <linux/types.h>
+#include <linux/bitrev.h>
 
 extern u32  crc32_le(u32 crc, unsigned char const *p, size_t len);
 extern u32  crc32_be(u32 crc, unsigned char const *p, size_t len);
-extern u32  bitreverse(u32 in);
 
 #define crc32(seed, data, length)  crc32_le(seed, (unsigned char const *)data, length)
 
@@ -21,7 +21,7 @@ extern u32  bitreverse(u32 in);
  * is in bit nr 0], thus it must be reversed before use. Except for
  * nics that bit swap the result internally...
  */
-#define ether_crc(length, data)    bitreverse(crc32_le(~0, data, length))
+#define ether_crc(length, data)    bitrev32(crc32_le(~0, data, length))
 #define ether_crc_le(length, data) crc32_le(~0, data, length)
 
 #endif /* _LINUX_CRC32_H */
diff --git a/lib/Kconfig b/lib/Kconfig
index 0d683559080e..47b172df3e31 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -26,6 +26,7 @@ config CRC16
 config CRC32
         tristate "CRC32 functions"
         default y
+        select BITREVERSE
         help
           This option is provided for the case where no in-kernel-tree
           modules require CRC32 functions, but a module built outside the
diff --git a/lib/crc32.c b/lib/crc32.c
index 285fd9bc61be..bfc33314c720 100644
--- a/lib/crc32.c
+++ b/lib/crc32.c
@@ -235,23 +235,8 @@ u32 __attribute_pure__ crc32_be(u32 crc, unsigned char const *p, size_t len)
 }
 #endif
 
-/**
- * bitreverse - reverse the order of bits in a u32 value
- * @x: value to be bit-reversed
- */
-u32 bitreverse(u32 x)
-{
-        x = (x >> 16) | (x << 16);
-        x = (x >> 8 & 0x00ff00ff) | (x << 8 & 0xff00ff00);
-        x = (x >> 4 & 0x0f0f0f0f) | (x << 4 & 0xf0f0f0f0);
-        x = (x >> 2 & 0x33333333) | (x << 2 & 0xcccccccc);
-        x = (x >> 1 & 0x55555555) | (x << 1 & 0xaaaaaaaa);
-        return x;
-}
-
 EXPORT_SYMBOL(crc32_le);
 EXPORT_SYMBOL(crc32_be);
-EXPORT_SYMBOL(bitreverse);
 
 /*
  * A brief CRC tutorial.
@@ -400,10 +385,7 @@ buf_dump(char const *prefix, unsigned char const *buf, size_t len)
 static void bytereverse(unsigned char *buf, size_t len)
 {
         while (len--) {
-                unsigned char x = *buf;
-                x = (x >> 4) | (x << 4);
-                x = (x >> 2 & 0x33) | (x << 2 & 0xcc);
-                x = (x >> 1 & 0x55) | (x << 1 & 0xaa);
+                unsigned char x = bitrev8(*buf);
                 *buf++ = x;
         }
 }
@@ -460,11 +442,11 @@ static u32 test_step(u32 init, unsigned char *buf, size_t len)
         /* Now swap it around for the other test */
 
         bytereverse(buf, len + 4);
-        init = bitreverse(init);
-        crc2 = bitreverse(crc1);
-        if (crc1 != bitreverse(crc2))
+        init = bitrev32(init);
+        crc2 = bitrev32(crc1);
+        if (crc1 != bitrev32(crc2))
                 printf("\nBit reversal fail: 0x%08x -> 0x%08x -> 0x%08x\n",
-                       crc1, crc2, bitreverse(crc2));
+                       crc1, crc2, bitrev32(crc2));
         crc1 = crc32_le(init, buf, len);
         if (crc1 != crc2)
                 printf("\nCRC endianness fail: 0x%08x != 0x%08x\n", crc1,