Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit d9fcca40 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-hash-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x86 hashing changes from Ingo Molnar:
 "Small fixes and cleanups to the librarized arch_fast_hash() methods,
  used by the net/openvswitch code"

* 'x86-hash-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, hash: Simplify switch, add __init annotation
  x86, hash: Swap arguments passed to crc32_u32()
  x86, hash: Fix build failure with older binutils
parents 7cc3afdf 7a5917e9

arch/x86/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -152,6 +152,7 @@ cfi-sections := $(call as-instr,.cfi_sections .debug_frame,-DCONFIG_AS_CFI_SECTI 


# does binutils support specific instructions?

asinstr := $(call as-instr,fxsaveq (%rax),-DCONFIG_AS_FXSAVEQ=1)

asinstr += $(call as-instr,crc32l %eax$(comma)%eax,-DCONFIG_AS_CRC32=1)

avx_instr := $(call as-instr,vxorps %ymm0$(comma)%ymm1$(comma)%ymm2,-DCONFIG_AS_AVX=1)

avx2_instr :=$(call as-instr,vpbroadcastb %xmm0$(comma)%ymm1,-DCONFIG_AS_AVX2=1)

arch/x86/lib/hash.c

+13 −9
Original line number Diff line number Diff line
@@ -32,6 +32,7 @@ 
 */



#include <linux/hash.h>

#include <linux/init.h>



#include <asm/processor.h>

#include <asm/cpufeature.h>
@@ -39,7 +40,11 @@ 


static inline u32 crc32_u32(u32 crc, u32 val)

{

#ifdef CONFIG_AS_CRC32

	asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val));

#else

	asm (".byte 0xf2, 0x0f, 0x38, 0xf1, 0xc1" : "+a" (crc) : "c" (val));

#endif

	return crc;

}
@@ -49,19 +54,18 @@ static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed) 
	u32 i, tmp = 0;



	for (i = 0; i < len / 4; i++)

		seed = crc32_u32(*p32++, seed);

		seed = crc32_u32(seed, *p32++);



	switch (3 - (len & 0x03)) {

	case 0:

	switch (len & 3) {

	case 3:

		tmp |= *((const u8 *) p32 + 2) << 16;

		/* fallthrough */

	case 1:

	case 2:

		tmp |= *((const u8 *) p32 + 1) << 8;

		/* fallthrough */

	case 2:

	case 1:

		tmp |= *((const u8 *) p32);

		seed = crc32_u32(tmp, seed);

	default:

		seed = crc32_u32(seed, tmp);

		break;

	}
@@ -74,12 +78,12 @@ static u32 intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed) 
	u32 i;



	for (i = 0; i < len; i++)

		seed = crc32_u32(*p32++, seed);

		seed = crc32_u32(seed, *p32++);



	return seed;

}



void setup_arch_fast_hash(struct fast_hash_ops *ops)

void __init setup_arch_fast_hash(struct fast_hash_ops *ops)

{

	if (cpu_has_xmm4_2) {

		ops->hash  = intel_crc4_2_hash;