crc32: make CRC_*_BITS definition correspond to actual bit counts

[linux-2.6-block.git] / lib / crc32defs.h

diff --git a/lib/crc32defs.h b/lib/crc32defs.h
index 9b6773d737495566846c66ab36c62b468ff88ab5..daa3a5e85f60a40d149aa68d6210227b6e8d63ef 100644 (file)
--- a/lib/crc32defs.h
+++ b/lib/crc32defs.h
@@ -6,27 +6,29 @@
 #define CRCPOLY_LE 0xedb88320
 #define CRCPOLY_BE 0x04c11db7
 
-/* How many bits at a time to use.  Requires a table of 4<<CRC_xx_BITS bytes. */
-/* For less performance-sensitive, use 4 */
-#ifndef CRC_LE_BITS 
-# define CRC_LE_BITS 8
+/* How many bits at a time to use.  Valid values are 1, 2, 4, 8, and 32. */
+/* For less performance-sensitive, use 4 or 8 */
+#ifndef CRC_LE_BITS
+# define CRC_LE_BITS 32
 #endif
 #ifndef CRC_BE_BITS
-# define CRC_BE_BITS 8
+# define CRC_BE_BITS 32
 #endif
 
 /*
  * Little-endian CRC computation.  Used with serial bit streams sent
  * lsbit-first.  Be sure to use cpu_to_le32() to append the computed CRC.
  */
-#if CRC_LE_BITS > 8 || CRC_LE_BITS < 1 || CRC_LE_BITS & CRC_LE_BITS-1
-# error CRC_LE_BITS must be a power of 2 between 1 and 8
+#if CRC_LE_BITS > 32 || CRC_LE_BITS < 1 || CRC_LE_BITS == 16 || \
+       CRC_LE_BITS & CRC_LE_BITS-1
+# error "CRC_LE_BITS must be one of {1, 2, 4, 8, 32}"
 #endif
 
 /*
  * Big-endian CRC computation.  Used with serial bit streams sent
  * msbit-first.  Be sure to use cpu_to_be32() to append the computed CRC.
  */
-#if CRC_BE_BITS > 8 || CRC_BE_BITS < 1 || CRC_BE_BITS & CRC_BE_BITS-1
-# error CRC_BE_BITS must be a power of 2 between 1 and 8
+#if CRC_BE_BITS > 32 || CRC_BE_BITS < 1 || CRC_BE_BITS == 16 || \
+       CRC_BE_BITS & CRC_BE_BITS-1
+# error "CRC_BE_BITS must be one of {1, 2, 4, 8, 32}"
 #endif