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authorChris Mason <chris.mason@oracle.com>2009-01-07 19:56:59 -0500
committerChris Mason <chris.mason@oracle.com>2009-01-07 19:56:59 -0500
commit755efdc3c4d3b42d5ffcef0f4d6e5b37ecd3bf21 (patch)
treeb3eadbdf6d472189a7221080b7e44f2ff0f0ef7b /fs
parent709ac06a148a33493d3e2f9391bb746b067d96d6 (diff)
Btrfs: Drop the hardware crc32c asm code
This is already in the arch specific directories in mainline and shouldn't be copied into btrfs. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/crc32c.h97
1 files changed, 3 insertions, 94 deletions
diff --git a/fs/btrfs/crc32c.h b/fs/btrfs/crc32c.h
index 1eaf11d334f..6e1b3de3670 100644
--- a/fs/btrfs/crc32c.h
+++ b/fs/btrfs/crc32c.h
@@ -18,103 +18,12 @@
#ifndef __BTRFS_CRC32C__
#define __BTRFS_CRC32C__
-#include <asm/byteorder.h>
#include <linux/crc32c.h>
-#include <linux/version.h>
-/* #define CONFIG_BTRFS_HW_SUM 1 */
-
-#ifdef CONFIG_BTRFS_HW_SUM
-#ifdef CONFIG_X86
/*
- * Using hardware provided CRC32 instruction to accelerate the CRC32 disposal.
- * CRC32C polynomial:0x1EDC6F41(BE)/0x82F63B78(LE)
- * CRC32 is a new instruction in Intel SSE4.2, the reference can be found at:
- * http://www.intel.com/products/processor/manuals/
- * Intel(R) 64 and IA-32 Architectures Software Developer's Manual
- * Volume 2A: Instruction Set Reference, A-M
- */
-
-#include <asm/cpufeature.h>
-#include <asm/processor.h>
-
-#define X86_FEATURE_XMM4_2 (4*32+20) /* Streaming SIMD Extensions-4.2 */
-#define cpu_has_xmm4_2 boot_cpu_has(X86_FEATURE_XMM4_2)
-
-#ifdef CONFIG_X86_64
-#define REX_PRE "0x48, "
-#define SCALE_F 8
-#else
-#define REX_PRE
-#define SCALE_F 4
-#endif
-
-static inline u32 btrfs_crc32c_le_hw_byte(u32 crc, unsigned char const *data,
- size_t length)
-{
- while (length--) {
- __asm__ __volatile__(
- ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
- :"=S"(crc)
- :"0"(crc), "c"(*data)
- );
- data++;
- }
-
- return crc;
-}
-
-static inline u32 __pure btrfs_crc32c_le_hw(u32 crc, unsigned char const *p,
- size_t len)
-{
- unsigned int iquotient = len / SCALE_F;
- unsigned int iremainder = len % SCALE_F;
-#ifdef CONFIG_X86_64
- u64 *ptmp = (u64 *)p;
-#else
- u32 *ptmp = (u32 *)p;
-#endif
-
- while (iquotient--) {
- __asm__ __volatile__(
- ".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
- :"=S"(crc)
- :"0"(crc), "c"(*ptmp)
- );
- ptmp++;
- }
-
- if (iremainder)
- crc = btrfs_crc32c_le_hw_byte(crc, (unsigned char *)ptmp,
- iremainder);
-
- return crc;
-}
-#endif /* CONFIG_BTRFS_HW_SUM */
-
-static inline u32 __btrfs_crc32c(u32 crc, unsigned char const *address,
- size_t len)
-{
-#ifdef CONFIG_BTRFS_HW_SUM
- if (cpu_has_xmm4_2)
- return btrfs_crc32c_le_hw(crc, address, len);
-#endif
- return crc32c_le(crc, address, len);
-}
-
-#else
-
-#define __btrfs_crc32c(seed, data, length) crc32c(seed, data, length)
-
-#endif /* CONFIG_X86 */
-
-/**
- * implementation of crc32c_le() changed in linux-2.6.23,
- * has of v0.13 btrfs-progs is using the latest version.
- * We must workaround older implementations of crc32c_le()
- * found on older kernel versions.
+ * this file used to do more for selecting the HW version of crc32c,
+ * perhaps it will one day again soon.
*/
-#define btrfs_crc32c(seed, data, length) \
- __btrfs_crc32c(seed, (unsigned char const *)data, length)
+#define btrfs_crc32c(seed, data, length) crc32c(seed, data, length)
#endif