[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>

2 files changed, 6 insertions, 23 deletions

diff --git a/lib/Kconfig b/lib/Kconfig
index 0d683559080..47b172df3e3 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 285fd9bc61b..bfc33314c72 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,