| Francesco Fusco | 71ae8aa | 2013-12-12 16:09:05 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Some portions derived from code covered by the following notice: |
| 3 | * |
| 4 | * Copyright (c) 2010-2013 Intel Corporation. All rights reserved. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * |
| 11 | * * Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * * Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in |
| 15 | * the documentation and/or other materials provided with the |
| 16 | * distribution. |
| 17 | * * Neither the name of Intel Corporation nor the names of its |
| 18 | * contributors may be used to endorse or promote products derived |
| 19 | * from this software without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 22 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 23 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 24 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 25 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 26 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 27 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 28 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 29 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 30 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 31 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | #include <linux/hash.h> |
| 35 | |
| 36 | #include <asm/processor.h> |
| 37 | #include <asm/cpufeature.h> |
| 38 | #include <asm/hash.h> |
| 39 | |
| 40 | static inline u32 crc32_u32(u32 crc, u32 val) |
| 41 | { |
| 42 | asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val)); |
| 43 | return crc; |
| 44 | } |
| 45 | |
| 46 | static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed) |
| 47 | { |
| 48 | const u32 *p32 = (const u32 *) data; |
| 49 | u32 i, tmp = 0; |
| 50 | |
| 51 | for (i = 0; i < len / 4; i++) |
| 52 | seed = crc32_u32(*p32++, seed); |
| 53 | |
| 54 | switch (3 - (len & 0x03)) { |
| 55 | case 0: |
| 56 | tmp |= *((const u8 *) p32 + 2) << 16; |
| 57 | /* fallthrough */ |
| 58 | case 1: |
| 59 | tmp |= *((const u8 *) p32 + 1) << 8; |
| 60 | /* fallthrough */ |
| 61 | case 2: |
| 62 | tmp |= *((const u8 *) p32); |
| 63 | seed = crc32_u32(tmp, seed); |
| 64 | default: |
| 65 | break; |
| 66 | } |
| 67 | |
| 68 | return seed; |
| 69 | } |
| 70 | |
| 71 | static u32 intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed) |
| 72 | { |
| 73 | const u32 *p32 = (const u32 *) data; |
| 74 | u32 i; |
| 75 | |
| 76 | for (i = 0; i < len; i++) |
| 77 | seed = crc32_u32(*p32++, seed); |
| 78 | |
| 79 | return seed; |
| 80 | } |
| 81 | |
| 82 | void setup_arch_fast_hash(struct fast_hash_ops *ops) |
| 83 | { |
| 84 | if (cpu_has_xmm4_2) { |
| 85 | ops->hash = intel_crc4_2_hash; |
| 86 | ops->hash2 = intel_crc4_2_hash2; |
| 87 | } |
| 88 | } |