From: Chris Mason <chris.mason@oracle.com>
Date: Thu, 8 Jan 2009 00:56:59 +0000 (-0500)
Subject: Btrfs: Drop the hardware crc32c asm code
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=755efdc3c4d3b42d5ffcef0f4d6e5b37ecd3bf21;p=openwrt%2Fstaging%2Fblogic.git

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>
---

diff --git a/fs/btrfs/crc32c.h b/fs/btrfs/crc32c.h
index 1eaf11d334fd..6e1b3de36700 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