diff options
Diffstat (limited to 'arch/x86/lib')
| -rw-r--r-- | arch/x86/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/x86/lib/hash.c | 88 |
2 files changed, 89 insertions, 1 deletions
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 992d63bb154f..eabcb6e6a900 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -24,7 +24,7 @@ lib-$(CONFIG_SMP) += rwlock.o lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o -obj-y += msr.o msr-reg.o msr-reg-export.o +obj-y += msr.o msr-reg.o msr-reg-export.o hash.o ifeq ($(CONFIG_X86_32),y) obj-y += atomic64_32.o diff --git a/arch/x86/lib/hash.c b/arch/x86/lib/hash.c new file mode 100644 index 000000000000..3056702e81fb --- /dev/null +++ b/arch/x86/lib/hash.c @@ -0,0 +1,88 @@ +/* + * Some portions derived from code covered by the following notice: + * + * Copyright (c) 2010-2013 Intel Corporation. All rights reserved. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#include <linux/hash.h> + +#include <asm/processor.h> +#include <asm/cpufeature.h> +#include <asm/hash.h> + +static inline u32 crc32_u32(u32 crc, u32 val) +{ + asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val)); + return crc; +} + +static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed) +{ + const u32 *p32 = (const u32 *) data; + u32 i, tmp = 0; + + for (i = 0; i < len / 4; i++) + seed = crc32_u32(*p32++, seed); + + switch (3 - (len & 0x03)) { + case 0: + tmp |= *((const u8 *) p32 + 2) << 16; + /* fallthrough */ + case 1: + tmp |= *((const u8 *) p32 + 1) << 8; + /* fallthrough */ + case 2: + tmp |= *((const u8 *) p32); + seed = crc32_u32(tmp, seed); + default: + break; + } + + return seed; +} + +static u32 intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed) +{ + const u32 *p32 = (const u32 *) data; + u32 i; + + for (i = 0; i < len; i++) + seed = crc32_u32(*p32++, seed); + + return seed; +} + +void setup_arch_fast_hash(struct fast_hash_ops *ops) +{ + if (cpu_has_xmm4_2) { + ops->hash = intel_crc4_2_hash; + ops->hash2 = intel_crc4_2_hash2; + } +} |