| 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
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| 2 | /* |
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| 3 | * Core of the accelerated CRC algorithm. |
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| 4 | * In your file, define the constants and CRC_FUNCTION_NAME |
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| 5 | * Then include this file. |
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| 6 | * |
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| 7 | * Calculate the checksum of data that is 16 byte aligned and a multiple of |
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| 8 | * 16 bytes. |
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| 9 | * |
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| 10 | * The first step is to reduce it to 1024 bits. We do this in 8 parallel |
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| 11 | * chunks in order to mask the latency of the vpmsum instructions. If we |
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| 12 | * have more than 32 kB of data to checksum we repeat this step multiple |
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| 13 | * times, passing in the previous 1024 bits. |
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| 14 | * |
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| 15 | * The next step is to reduce the 1024 bits to 64 bits. This step adds |
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| 16 | * 32 bits of 0s to the end - this matches what a CRC does. We just |
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| 17 | * calculate constants that land the data in this 32 bits. |
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| 18 | * |
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| 19 | * We then use fixed point Barrett reduction to compute a mod n over GF(2) |
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| 20 | * for n = CRC using POWER8 instructions. We use x = 32. |
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| 21 | * |
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| 22 | * https://en.wikipedia.org/wiki/Barrett_reduction |
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| 23 | * |
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| 24 | * Copyright (C) 2015 Anton Blanchard <anton@au.ibm.com>, IBM |
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| 25 | */ |
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| 26 | |
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| 27 | #include <asm/ppc_asm.h> |
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| 28 | #include <asm/ppc-opcode.h> |
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| 29 | |
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| 30 | #define MAX_SIZE 32768 |
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| 31 | |
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| 32 | .text |
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| 33 | |
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| 34 | #if defined(__BIG_ENDIAN__) && defined(REFLECT) |
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| 35 | #define BYTESWAP_DATA |
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| 36 | #elif defined(__LITTLE_ENDIAN__) && !defined(REFLECT) |
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| 37 | #define BYTESWAP_DATA |
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| 38 | #else |
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| 39 | #undef BYTESWAP_DATA |
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| 40 | #endif |
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| 41 | |
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| 42 | #define off16 r25 |
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| 43 | #define off32 r26 |
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| 44 | #define off48 r27 |
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| 45 | #define off64 r28 |
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| 46 | #define off80 r29 |
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| 47 | #define off96 r30 |
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| 48 | #define off112 r31 |
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| 49 | |
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| 50 | #define const1 v24 |
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| 51 | #define const2 v25 |
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| 52 | |
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| 53 | #define byteswap v26 |
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| 54 | #define mask_32bit v27 |
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| 55 | #define mask_64bit v28 |
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| 56 | #define zeroes v29 |
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| 57 | |
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| 58 | #ifdef BYTESWAP_DATA |
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| 59 | #define VPERM(A, B, C, D) vperm A, B, C, D |
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| 60 | #else |
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| 61 | #define VPERM(A, B, C, D) |
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| 62 | #endif |
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| 63 | |
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| 64 | /* unsigned int CRC_FUNCTION_NAME(unsigned int crc, void *p, unsigned long len) */ |
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| 65 | FUNC_START(CRC_FUNCTION_NAME) |
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| 66 | std r31,-8(r1) |
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| 67 | std r30,-16(r1) |
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| 68 | std r29,-24(r1) |
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| 69 | std r28,-32(r1) |
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| 70 | std r27,-40(r1) |
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| 71 | std r26,-48(r1) |
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| 72 | std r25,-56(r1) |
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| 73 | |
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| 74 | li off16,16 |
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| 75 | li off32,32 |
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| 76 | li off48,48 |
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| 77 | li off64,64 |
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| 78 | li off80,80 |
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| 79 | li off96,96 |
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| 80 | li off112,112 |
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| 81 | li r0,0 |
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| 82 | |
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| 83 | /* Enough room for saving 10 non volatile VMX registers */ |
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| 84 | subi r6,r1,56+10*16 |
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| 85 | subi r7,r1,56+2*16 |
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| 86 | |
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| 87 | stvx v20,0,r6 |
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| 88 | stvx v21,off16,r6 |
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| 89 | stvx v22,off32,r6 |
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| 90 | stvx v23,off48,r6 |
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| 91 | stvx v24,off64,r6 |
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| 92 | stvx v25,off80,r6 |
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| 93 | stvx v26,off96,r6 |
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| 94 | stvx v27,off112,r6 |
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| 95 | stvx v28,0,r7 |
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| 96 | stvx v29,off16,r7 |
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| 97 | |
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| 98 | mr r10,r3 |
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| 99 | |
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| 100 | vxor zeroes,zeroes,zeroes |
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| 101 | vspltisw v0,-1 |
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| 102 | |
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| 103 | vsldoi mask_32bit,zeroes,v0,4 |
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| 104 | vsldoi mask_64bit,zeroes,v0,8 |
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| 105 | |
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| 106 | /* Get the initial value into v8 */ |
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| 107 | vxor v8,v8,v8 |
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| 108 | MTVRD(v8, R3) |
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| 109 | #ifdef REFLECT |
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| 110 | vsldoi v8,zeroes,v8,8 /* shift into bottom 32 bits */ |
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| 111 | #else |
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| 112 | vsldoi v8,v8,zeroes,4 /* shift into top 32 bits */ |
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| 113 | #endif |
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| 114 | |
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| 115 | #ifdef BYTESWAP_DATA |
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| 116 | LOAD_REG_ADDR(r3, .byteswap_constant) |
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| 117 | lvx byteswap,0,r3 |
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| 118 | addi r3,r3,16 |
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| 119 | #endif |
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| 120 | |
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| 121 | cmpdi r5,256 |
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| 122 | blt .Lshort |
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| 123 | |
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| 124 | rldicr r6,r5,0,56 |
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| 125 | |
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| 126 | /* Checksum in blocks of MAX_SIZE */ |
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| 127 | 1: lis r7,MAX_SIZE@h |
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| 128 | ori r7,r7,MAX_SIZE@l |
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| 129 | mr r9,r7 |
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| 130 | cmpd r6,r7 |
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| 131 | bgt 2f |
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| 132 | mr r7,r6 |
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| 133 | 2: subf r6,r7,r6 |
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| 134 | |
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| 135 | /* our main loop does 128 bytes at a time */ |
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| 136 | srdi r7,r7,7 |
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| 137 | |
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| 138 | /* |
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| 139 | * Work out the offset into the constants table to start at. Each |
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| 140 | * constant is 16 bytes, and it is used against 128 bytes of input |
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| 141 | * data - 128 / 16 = 8 |
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| 142 | */ |
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| 143 | sldi r8,r7,4 |
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| 144 | srdi r9,r9,3 |
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| 145 | subf r8,r8,r9 |
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| 146 | |
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| 147 | /* We reduce our final 128 bytes in a separate step */ |
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| 148 | addi r7,r7,-1 |
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| 149 | mtctr r7 |
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| 150 | |
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| 151 | LOAD_REG_ADDR(r3, .constants) |
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| 152 | |
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| 153 | /* Find the start of our constants */ |
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| 154 | add r3,r3,r8 |
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| 155 | |
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| 156 | /* zero v0-v7 which will contain our checksums */ |
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| 157 | vxor v0,v0,v0 |
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| 158 | vxor v1,v1,v1 |
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| 159 | vxor v2,v2,v2 |
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| 160 | vxor v3,v3,v3 |
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| 161 | vxor v4,v4,v4 |
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| 162 | vxor v5,v5,v5 |
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| 163 | vxor v6,v6,v6 |
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| 164 | vxor v7,v7,v7 |
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| 165 | |
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| 166 | lvx const1,0,r3 |
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| 167 | |
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| 168 | /* |
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| 169 | * If we are looping back to consume more data we use the values |
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| 170 | * already in v16-v23. |
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| 171 | */ |
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| 172 | cmpdi r0,1 |
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| 173 | beq 2f |
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| 174 | |
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| 175 | /* First warm up pass */ |
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| 176 | lvx v16,0,r4 |
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| 177 | lvx v17,off16,r4 |
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| 178 | VPERM(v16,v16,v16,byteswap) |
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| 179 | VPERM(v17,v17,v17,byteswap) |
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| 180 | lvx v18,off32,r4 |
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| 181 | lvx v19,off48,r4 |
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| 182 | VPERM(v18,v18,v18,byteswap) |
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| 183 | VPERM(v19,v19,v19,byteswap) |
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| 184 | lvx v20,off64,r4 |
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| 185 | lvx v21,off80,r4 |
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| 186 | VPERM(v20,v20,v20,byteswap) |
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| 187 | VPERM(v21,v21,v21,byteswap) |
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| 188 | lvx v22,off96,r4 |
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| 189 | lvx v23,off112,r4 |
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| 190 | VPERM(v22,v22,v22,byteswap) |
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| 191 | VPERM(v23,v23,v23,byteswap) |
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| 192 | addi r4,r4,8*16 |
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| 193 | |
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| 194 | /* xor in initial value */ |
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| 195 | vxor v16,v16,v8 |
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| 196 | |
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| 197 | 2: bdz .Lfirst_warm_up_done |
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| 198 | |
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| 199 | addi r3,r3,16 |
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| 200 | lvx const2,0,r3 |
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| 201 | |
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| 202 | /* Second warm up pass */ |
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| 203 | VPMSUMD(v8,v16,const1) |
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| 204 | lvx v16,0,r4 |
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| 205 | VPERM(v16,v16,v16,byteswap) |
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| 206 | ori r2,r2,0 |
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| 207 | |
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| 208 | VPMSUMD(v9,v17,const1) |
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| 209 | lvx v17,off16,r4 |
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| 210 | VPERM(v17,v17,v17,byteswap) |
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| 211 | ori r2,r2,0 |
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| 212 | |
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| 213 | VPMSUMD(v10,v18,const1) |
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| 214 | lvx v18,off32,r4 |
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| 215 | VPERM(v18,v18,v18,byteswap) |
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| 216 | ori r2,r2,0 |
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| 217 | |
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| 218 | VPMSUMD(v11,v19,const1) |
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| 219 | lvx v19,off48,r4 |
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| 220 | VPERM(v19,v19,v19,byteswap) |
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| 221 | ori r2,r2,0 |
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| 222 | |
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| 223 | VPMSUMD(v12,v20,const1) |
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| 224 | lvx v20,off64,r4 |
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| 225 | VPERM(v20,v20,v20,byteswap) |
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| 226 | ori r2,r2,0 |
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| 227 | |
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| 228 | VPMSUMD(v13,v21,const1) |
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| 229 | lvx v21,off80,r4 |
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| 230 | VPERM(v21,v21,v21,byteswap) |
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| 231 | ori r2,r2,0 |
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| 232 | |
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| 233 | VPMSUMD(v14,v22,const1) |
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| 234 | lvx v22,off96,r4 |
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| 235 | VPERM(v22,v22,v22,byteswap) |
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| 236 | ori r2,r2,0 |
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| 237 | |
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| 238 | VPMSUMD(v15,v23,const1) |
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| 239 | lvx v23,off112,r4 |
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| 240 | VPERM(v23,v23,v23,byteswap) |
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| 241 | |
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| 242 | addi r4,r4,8*16 |
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| 243 | |
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| 244 | bdz .Lfirst_cool_down |
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| 245 | |
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| 246 | /* |
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| 247 | * main loop. We modulo schedule it such that it takes three iterations |
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| 248 | * to complete - first iteration load, second iteration vpmsum, third |
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| 249 | * iteration xor. |
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| 250 | */ |
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| 251 | .balign 16 |
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| 252 | 4: lvx const1,0,r3 |
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| 253 | addi r3,r3,16 |
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| 254 | ori r2,r2,0 |
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| 255 | |
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| 256 | vxor v0,v0,v8 |
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| 257 | VPMSUMD(v8,v16,const2) |
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| 258 | lvx v16,0,r4 |
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| 259 | VPERM(v16,v16,v16,byteswap) |
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| 260 | ori r2,r2,0 |
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| 261 | |
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| 262 | vxor v1,v1,v9 |
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| 263 | VPMSUMD(v9,v17,const2) |
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| 264 | lvx v17,off16,r4 |
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| 265 | VPERM(v17,v17,v17,byteswap) |
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| 266 | ori r2,r2,0 |
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| 267 | |
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| 268 | vxor v2,v2,v10 |
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| 269 | VPMSUMD(v10,v18,const2) |
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| 270 | lvx v18,off32,r4 |
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| 271 | VPERM(v18,v18,v18,byteswap) |
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| 272 | ori r2,r2,0 |
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| 273 | |
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| 274 | vxor v3,v3,v11 |
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| 275 | VPMSUMD(v11,v19,const2) |
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| 276 | lvx v19,off48,r4 |
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| 277 | VPERM(v19,v19,v19,byteswap) |
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| 278 | lvx const2,0,r3 |
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| 279 | ori r2,r2,0 |
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| 280 | |
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| 281 | vxor v4,v4,v12 |
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| 282 | VPMSUMD(v12,v20,const1) |
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| 283 | lvx v20,off64,r4 |
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| 284 | VPERM(v20,v20,v20,byteswap) |
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| 285 | ori r2,r2,0 |
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| 286 | |
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| 287 | vxor v5,v5,v13 |
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| 288 | VPMSUMD(v13,v21,const1) |
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| 289 | lvx v21,off80,r4 |
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| 290 | VPERM(v21,v21,v21,byteswap) |
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| 291 | ori r2,r2,0 |
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| 292 | |
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| 293 | vxor v6,v6,v14 |
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| 294 | VPMSUMD(v14,v22,const1) |
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| 295 | lvx v22,off96,r4 |
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| 296 | VPERM(v22,v22,v22,byteswap) |
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| 297 | ori r2,r2,0 |
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| 298 | |
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| 299 | vxor v7,v7,v15 |
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| 300 | VPMSUMD(v15,v23,const1) |
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| 301 | lvx v23,off112,r4 |
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| 302 | VPERM(v23,v23,v23,byteswap) |
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| 303 | |
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| 304 | addi r4,r4,8*16 |
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| 305 | |
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| 306 | bdnz 4b |
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| 307 | |
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| 308 | .Lfirst_cool_down: |
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| 309 | /* First cool down pass */ |
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| 310 | lvx const1,0,r3 |
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| 311 | addi r3,r3,16 |
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| 312 | |
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| 313 | vxor v0,v0,v8 |
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| 314 | VPMSUMD(v8,v16,const1) |
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| 315 | ori r2,r2,0 |
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| 316 | |
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| 317 | vxor v1,v1,v9 |
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| 318 | VPMSUMD(v9,v17,const1) |
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| 319 | ori r2,r2,0 |
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| 320 | |
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| 321 | vxor v2,v2,v10 |
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| 322 | VPMSUMD(v10,v18,const1) |
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| 323 | ori r2,r2,0 |
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| 324 | |
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| 325 | vxor v3,v3,v11 |
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| 326 | VPMSUMD(v11,v19,const1) |
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| 327 | ori r2,r2,0 |
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| 328 | |
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| 329 | vxor v4,v4,v12 |
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| 330 | VPMSUMD(v12,v20,const1) |
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| 331 | ori r2,r2,0 |
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| 332 | |
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| 333 | vxor v5,v5,v13 |
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| 334 | VPMSUMD(v13,v21,const1) |
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| 335 | ori r2,r2,0 |
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| 336 | |
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| 337 | vxor v6,v6,v14 |
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| 338 | VPMSUMD(v14,v22,const1) |
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| 339 | ori r2,r2,0 |
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| 340 | |
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| 341 | vxor v7,v7,v15 |
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| 342 | VPMSUMD(v15,v23,const1) |
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| 343 | ori r2,r2,0 |
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| 344 | |
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| 345 | .Lsecond_cool_down: |
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| 346 | /* Second cool down pass */ |
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| 347 | vxor v0,v0,v8 |
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| 348 | vxor v1,v1,v9 |
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| 349 | vxor v2,v2,v10 |
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| 350 | vxor v3,v3,v11 |
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| 351 | vxor v4,v4,v12 |
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| 352 | vxor v5,v5,v13 |
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| 353 | vxor v6,v6,v14 |
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| 354 | vxor v7,v7,v15 |
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| 355 | |
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| 356 | #ifdef REFLECT |
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| 357 | /* |
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| 358 | * vpmsumd produces a 96 bit result in the least significant bits |
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| 359 | * of the register. Since we are bit reflected we have to shift it |
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| 360 | * left 32 bits so it occupies the least significant bits in the |
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| 361 | * bit reflected domain. |
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| 362 | */ |
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| 363 | vsldoi v0,v0,zeroes,4 |
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| 364 | vsldoi v1,v1,zeroes,4 |
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| 365 | vsldoi v2,v2,zeroes,4 |
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| 366 | vsldoi v3,v3,zeroes,4 |
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| 367 | vsldoi v4,v4,zeroes,4 |
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| 368 | vsldoi v5,v5,zeroes,4 |
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| 369 | vsldoi v6,v6,zeroes,4 |
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| 370 | vsldoi v7,v7,zeroes,4 |
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| 371 | #endif |
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| 372 | |
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| 373 | /* xor with last 1024 bits */ |
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| 374 | lvx v8,0,r4 |
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| 375 | lvx v9,off16,r4 |
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| 376 | VPERM(v8,v8,v8,byteswap) |
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| 377 | VPERM(v9,v9,v9,byteswap) |
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| 378 | lvx v10,off32,r4 |
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| 379 | lvx v11,off48,r4 |
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| 380 | VPERM(v10,v10,v10,byteswap) |
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| 381 | VPERM(v11,v11,v11,byteswap) |
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| 382 | lvx v12,off64,r4 |
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| 383 | lvx v13,off80,r4 |
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| 384 | VPERM(v12,v12,v12,byteswap) |
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| 385 | VPERM(v13,v13,v13,byteswap) |
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| 386 | lvx v14,off96,r4 |
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| 387 | lvx v15,off112,r4 |
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| 388 | VPERM(v14,v14,v14,byteswap) |
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| 389 | VPERM(v15,v15,v15,byteswap) |
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| 390 | |
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| 391 | addi r4,r4,8*16 |
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| 392 | |
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| 393 | vxor v16,v0,v8 |
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| 394 | vxor v17,v1,v9 |
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| 395 | vxor v18,v2,v10 |
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| 396 | vxor v19,v3,v11 |
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| 397 | vxor v20,v4,v12 |
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| 398 | vxor v21,v5,v13 |
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| 399 | vxor v22,v6,v14 |
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| 400 | vxor v23,v7,v15 |
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| 401 | |
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| 402 | li r0,1 |
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| 403 | cmpdi r6,0 |
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| 404 | addi r6,r6,128 |
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| 405 | bne 1b |
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| 406 | |
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| 407 | /* Work out how many bytes we have left */ |
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| 408 | andi. r5,r5,127 |
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| 409 | |
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| 410 | /* Calculate where in the constant table we need to start */ |
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| 411 | subfic r6,r5,128 |
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| 412 | add r3,r3,r6 |
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| 413 | |
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| 414 | /* How many 16 byte chunks are in the tail */ |
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| 415 | srdi r7,r5,4 |
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| 416 | mtctr r7 |
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| 417 | |
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| 418 | /* |
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| 419 | * Reduce the previously calculated 1024 bits to 64 bits, shifting |
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| 420 | * 32 bits to include the trailing 32 bits of zeros |
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| 421 | */ |
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| 422 | lvx v0,0,r3 |
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| 423 | lvx v1,off16,r3 |
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| 424 | lvx v2,off32,r3 |
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| 425 | lvx v3,off48,r3 |
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| 426 | lvx v4,off64,r3 |
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| 427 | lvx v5,off80,r3 |
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| 428 | lvx v6,off96,r3 |
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| 429 | lvx v7,off112,r3 |
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| 430 | addi r3,r3,8*16 |
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| 431 | |
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| 432 | VPMSUMW(v0,v16,v0) |
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| 433 | VPMSUMW(v1,v17,v1) |
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| 434 | VPMSUMW(v2,v18,v2) |
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| 435 | VPMSUMW(v3,v19,v3) |
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| 436 | VPMSUMW(v4,v20,v4) |
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| 437 | VPMSUMW(v5,v21,v5) |
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| 438 | VPMSUMW(v6,v22,v6) |
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| 439 | VPMSUMW(v7,v23,v7) |
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| 440 | |
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| 441 | /* Now reduce the tail (0 - 112 bytes) */ |
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| 442 | cmpdi r7,0 |
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| 443 | beq 1f |
|---|
| 444 | |
|---|
| 445 | lvx v16,0,r4 |
|---|
| 446 | lvx v17,0,r3 |
|---|
| 447 | VPERM(v16,v16,v16,byteswap) |
|---|
| 448 | VPMSUMW(v16,v16,v17) |
|---|
| 449 | vxor v0,v0,v16 |
|---|
| 450 | bdz 1f |
|---|
| 451 | |
|---|
| 452 | lvx v16,off16,r4 |
|---|
| 453 | lvx v17,off16,r3 |
|---|
| 454 | VPERM(v16,v16,v16,byteswap) |
|---|
| 455 | VPMSUMW(v16,v16,v17) |
|---|
| 456 | vxor v0,v0,v16 |
|---|
| 457 | bdz 1f |
|---|
| 458 | |
|---|
| 459 | lvx v16,off32,r4 |
|---|
| 460 | lvx v17,off32,r3 |
|---|
| 461 | VPERM(v16,v16,v16,byteswap) |
|---|
| 462 | VPMSUMW(v16,v16,v17) |
|---|
| 463 | vxor v0,v0,v16 |
|---|
| 464 | bdz 1f |
|---|
| 465 | |
|---|
| 466 | lvx v16,off48,r4 |
|---|
| 467 | lvx v17,off48,r3 |
|---|
| 468 | VPERM(v16,v16,v16,byteswap) |
|---|
| 469 | VPMSUMW(v16,v16,v17) |
|---|
| 470 | vxor v0,v0,v16 |
|---|
| 471 | bdz 1f |
|---|
| 472 | |
|---|
| 473 | lvx v16,off64,r4 |
|---|
| 474 | lvx v17,off64,r3 |
|---|
| 475 | VPERM(v16,v16,v16,byteswap) |
|---|
| 476 | VPMSUMW(v16,v16,v17) |
|---|
| 477 | vxor v0,v0,v16 |
|---|
| 478 | bdz 1f |
|---|
| 479 | |
|---|
| 480 | lvx v16,off80,r4 |
|---|
| 481 | lvx v17,off80,r3 |
|---|
| 482 | VPERM(v16,v16,v16,byteswap) |
|---|
| 483 | VPMSUMW(v16,v16,v17) |
|---|
| 484 | vxor v0,v0,v16 |
|---|
| 485 | bdz 1f |
|---|
| 486 | |
|---|
| 487 | lvx v16,off96,r4 |
|---|
| 488 | lvx v17,off96,r3 |
|---|
| 489 | VPERM(v16,v16,v16,byteswap) |
|---|
| 490 | VPMSUMW(v16,v16,v17) |
|---|
| 491 | vxor v0,v0,v16 |
|---|
| 492 | |
|---|
| 493 | /* Now xor all the parallel chunks together */ |
|---|
| 494 | 1: vxor v0,v0,v1 |
|---|
| 495 | vxor v2,v2,v3 |
|---|
| 496 | vxor v4,v4,v5 |
|---|
| 497 | vxor v6,v6,v7 |
|---|
| 498 | |
|---|
| 499 | vxor v0,v0,v2 |
|---|
| 500 | vxor v4,v4,v6 |
|---|
| 501 | |
|---|
| 502 | vxor v0,v0,v4 |
|---|
| 503 | |
|---|
| 504 | .Lbarrett_reduction: |
|---|
| 505 | /* Barrett constants */ |
|---|
| 506 | LOAD_REG_ADDR(r3, .barrett_constants) |
|---|
| 507 | |
|---|
| 508 | lvx const1,0,r3 |
|---|
| 509 | lvx const2,off16,r3 |
|---|
| 510 | |
|---|
| 511 | vsldoi v1,v0,v0,8 |
|---|
| 512 | vxor v0,v0,v1 /* xor two 64 bit results together */ |
|---|
| 513 | |
|---|
| 514 | #ifdef REFLECT |
|---|
| 515 | /* shift left one bit */ |
|---|
| 516 | vspltisb v1,1 |
|---|
| 517 | vsl v0,v0,v1 |
|---|
| 518 | #endif |
|---|
| 519 | |
|---|
| 520 | vand v0,v0,mask_64bit |
|---|
| 521 | #ifndef REFLECT |
|---|
| 522 | /* |
|---|
| 523 | * Now for the Barrett reduction algorithm. The idea is to calculate q, |
|---|
| 524 | * the multiple of our polynomial that we need to subtract. By |
|---|
| 525 | * doing the computation 2x bits higher (ie 64 bits) and shifting the |
|---|
| 526 | * result back down 2x bits, we round down to the nearest multiple. |
|---|
| 527 | */ |
|---|
| 528 | VPMSUMD(v1,v0,const1) /* ma */ |
|---|
| 529 | vsldoi v1,zeroes,v1,8 /* q = floor(ma/(2^64)) */ |
|---|
| 530 | VPMSUMD(v1,v1,const2) /* qn */ |
|---|
| 531 | vxor v0,v0,v1 /* a - qn, subtraction is xor in GF(2) */ |
|---|
| 532 | |
|---|
| 533 | /* |
|---|
| 534 | * Get the result into r3. We need to shift it left 8 bytes: |
|---|
| 535 | * V0 [ 0 1 2 X ] |
|---|
| 536 | * V0 [ 0 X 2 3 ] |
|---|
| 537 | */ |
|---|
| 538 | vsldoi v0,v0,zeroes,8 /* shift result into top 64 bits */ |
|---|
| 539 | #else |
|---|
| 540 | /* |
|---|
| 541 | * The reflected version of Barrett reduction. Instead of bit |
|---|
| 542 | * reflecting our data (which is expensive to do), we bit reflect our |
|---|
| 543 | * constants and our algorithm, which means the intermediate data in |
|---|
| 544 | * our vector registers goes from 0-63 instead of 63-0. We can reflect |
|---|
| 545 | * the algorithm because we don't carry in mod 2 arithmetic. |
|---|
| 546 | */ |
|---|
| 547 | vand v1,v0,mask_32bit /* bottom 32 bits of a */ |
|---|
| 548 | VPMSUMD(v1,v1,const1) /* ma */ |
|---|
| 549 | vand v1,v1,mask_32bit /* bottom 32bits of ma */ |
|---|
| 550 | VPMSUMD(v1,v1,const2) /* qn */ |
|---|
| 551 | vxor v0,v0,v1 /* a - qn, subtraction is xor in GF(2) */ |
|---|
| 552 | |
|---|
| 553 | /* |
|---|
| 554 | * Since we are bit reflected, the result (ie the low 32 bits) is in |
|---|
| 555 | * the high 32 bits. We just need to shift it left 4 bytes |
|---|
| 556 | * V0 [ 0 1 X 3 ] |
|---|
| 557 | * V0 [ 0 X 2 3 ] |
|---|
| 558 | */ |
|---|
| 559 | vsldoi v0,v0,zeroes,4 /* shift result into top 64 bits of */ |
|---|
| 560 | #endif |
|---|
| 561 | |
|---|
| 562 | /* Get it into r3 */ |
|---|
| 563 | MFVRD(R3, v0) |
|---|
| 564 | |
|---|
| 565 | .Lout: |
|---|
| 566 | subi r6,r1,56+10*16 |
|---|
| 567 | subi r7,r1,56+2*16 |
|---|
| 568 | |
|---|
| 569 | lvx v20,0,r6 |
|---|
| 570 | lvx v21,off16,r6 |
|---|
| 571 | lvx v22,off32,r6 |
|---|
| 572 | lvx v23,off48,r6 |
|---|
| 573 | lvx v24,off64,r6 |
|---|
| 574 | lvx v25,off80,r6 |
|---|
| 575 | lvx v26,off96,r6 |
|---|
| 576 | lvx v27,off112,r6 |
|---|
| 577 | lvx v28,0,r7 |
|---|
| 578 | lvx v29,off16,r7 |
|---|
| 579 | |
|---|
| 580 | ld r31,-8(r1) |
|---|
| 581 | ld r30,-16(r1) |
|---|
| 582 | ld r29,-24(r1) |
|---|
| 583 | ld r28,-32(r1) |
|---|
| 584 | ld r27,-40(r1) |
|---|
| 585 | ld r26,-48(r1) |
|---|
| 586 | ld r25,-56(r1) |
|---|
| 587 | |
|---|
| 588 | blr |
|---|
| 589 | |
|---|
| 590 | .Lfirst_warm_up_done: |
|---|
| 591 | lvx const1,0,r3 |
|---|
| 592 | addi r3,r3,16 |
|---|
| 593 | |
|---|
| 594 | VPMSUMD(v8,v16,const1) |
|---|
| 595 | VPMSUMD(v9,v17,const1) |
|---|
| 596 | VPMSUMD(v10,v18,const1) |
|---|
| 597 | VPMSUMD(v11,v19,const1) |
|---|
| 598 | VPMSUMD(v12,v20,const1) |
|---|
| 599 | VPMSUMD(v13,v21,const1) |
|---|
| 600 | VPMSUMD(v14,v22,const1) |
|---|
| 601 | VPMSUMD(v15,v23,const1) |
|---|
| 602 | |
|---|
| 603 | b .Lsecond_cool_down |
|---|
| 604 | |
|---|
| 605 | .Lshort: |
|---|
| 606 | cmpdi r5,0 |
|---|
| 607 | beq .Lzero |
|---|
| 608 | |
|---|
| 609 | LOAD_REG_ADDR(r3, .short_constants) |
|---|
| 610 | |
|---|
| 611 | /* Calculate where in the constant table we need to start */ |
|---|
| 612 | subfic r6,r5,256 |
|---|
| 613 | add r3,r3,r6 |
|---|
| 614 | |
|---|
| 615 | /* How many 16 byte chunks? */ |
|---|
| 616 | srdi r7,r5,4 |
|---|
| 617 | mtctr r7 |
|---|
| 618 | |
|---|
| 619 | vxor v19,v19,v19 |
|---|
| 620 | vxor v20,v20,v20 |
|---|
| 621 | |
|---|
| 622 | lvx v0,0,r4 |
|---|
| 623 | lvx v16,0,r3 |
|---|
| 624 | VPERM(v0,v0,v16,byteswap) |
|---|
| 625 | vxor v0,v0,v8 /* xor in initial value */ |
|---|
| 626 | VPMSUMW(v0,v0,v16) |
|---|
| 627 | bdz .Lv0 |
|---|
| 628 | |
|---|
| 629 | lvx v1,off16,r4 |
|---|
| 630 | lvx v17,off16,r3 |
|---|
| 631 | VPERM(v1,v1,v17,byteswap) |
|---|
| 632 | VPMSUMW(v1,v1,v17) |
|---|
| 633 | bdz .Lv1 |
|---|
| 634 | |
|---|
| 635 | lvx v2,off32,r4 |
|---|
| 636 | lvx v16,off32,r3 |
|---|
| 637 | VPERM(v2,v2,v16,byteswap) |
|---|
| 638 | VPMSUMW(v2,v2,v16) |
|---|
| 639 | bdz .Lv2 |
|---|
| 640 | |
|---|
| 641 | lvx v3,off48,r4 |
|---|
| 642 | lvx v17,off48,r3 |
|---|
| 643 | VPERM(v3,v3,v17,byteswap) |
|---|
| 644 | VPMSUMW(v3,v3,v17) |
|---|
| 645 | bdz .Lv3 |
|---|
| 646 | |
|---|
| 647 | lvx v4,off64,r4 |
|---|
| 648 | lvx v16,off64,r3 |
|---|
| 649 | VPERM(v4,v4,v16,byteswap) |
|---|
| 650 | VPMSUMW(v4,v4,v16) |
|---|
| 651 | bdz .Lv4 |
|---|
| 652 | |
|---|
| 653 | lvx v5,off80,r4 |
|---|
| 654 | lvx v17,off80,r3 |
|---|
| 655 | VPERM(v5,v5,v17,byteswap) |
|---|
| 656 | VPMSUMW(v5,v5,v17) |
|---|
| 657 | bdz .Lv5 |
|---|
| 658 | |
|---|
| 659 | lvx v6,off96,r4 |
|---|
| 660 | lvx v16,off96,r3 |
|---|
| 661 | VPERM(v6,v6,v16,byteswap) |
|---|
| 662 | VPMSUMW(v6,v6,v16) |
|---|
| 663 | bdz .Lv6 |
|---|
| 664 | |
|---|
| 665 | lvx v7,off112,r4 |
|---|
| 666 | lvx v17,off112,r3 |
|---|
| 667 | VPERM(v7,v7,v17,byteswap) |
|---|
| 668 | VPMSUMW(v7,v7,v17) |
|---|
| 669 | bdz .Lv7 |
|---|
| 670 | |
|---|
| 671 | addi r3,r3,128 |
|---|
| 672 | addi r4,r4,128 |
|---|
| 673 | |
|---|
| 674 | lvx v8,0,r4 |
|---|
| 675 | lvx v16,0,r3 |
|---|
| 676 | VPERM(v8,v8,v16,byteswap) |
|---|
| 677 | VPMSUMW(v8,v8,v16) |
|---|
| 678 | bdz .Lv8 |
|---|
| 679 | |
|---|
| 680 | lvx v9,off16,r4 |
|---|
| 681 | lvx v17,off16,r3 |
|---|
| 682 | VPERM(v9,v9,v17,byteswap) |
|---|
| 683 | VPMSUMW(v9,v9,v17) |
|---|
| 684 | bdz .Lv9 |
|---|
| 685 | |
|---|
| 686 | lvx v10,off32,r4 |
|---|
| 687 | lvx v16,off32,r3 |
|---|
| 688 | VPERM(v10,v10,v16,byteswap) |
|---|
| 689 | VPMSUMW(v10,v10,v16) |
|---|
| 690 | bdz .Lv10 |
|---|
| 691 | |
|---|
| 692 | lvx v11,off48,r4 |
|---|
| 693 | lvx v17,off48,r3 |
|---|
| 694 | VPERM(v11,v11,v17,byteswap) |
|---|
| 695 | VPMSUMW(v11,v11,v17) |
|---|
| 696 | bdz .Lv11 |
|---|
| 697 | |
|---|
| 698 | lvx v12,off64,r4 |
|---|
| 699 | lvx v16,off64,r3 |
|---|
| 700 | VPERM(v12,v12,v16,byteswap) |
|---|
| 701 | VPMSUMW(v12,v12,v16) |
|---|
| 702 | bdz .Lv12 |
|---|
| 703 | |
|---|
| 704 | lvx v13,off80,r4 |
|---|
| 705 | lvx v17,off80,r3 |
|---|
| 706 | VPERM(v13,v13,v17,byteswap) |
|---|
| 707 | VPMSUMW(v13,v13,v17) |
|---|
| 708 | bdz .Lv13 |
|---|
| 709 | |
|---|
| 710 | lvx v14,off96,r4 |
|---|
| 711 | lvx v16,off96,r3 |
|---|
| 712 | VPERM(v14,v14,v16,byteswap) |
|---|
| 713 | VPMSUMW(v14,v14,v16) |
|---|
| 714 | bdz .Lv14 |
|---|
| 715 | |
|---|
| 716 | lvx v15,off112,r4 |
|---|
| 717 | lvx v17,off112,r3 |
|---|
| 718 | VPERM(v15,v15,v17,byteswap) |
|---|
| 719 | VPMSUMW(v15,v15,v17) |
|---|
| 720 | |
|---|
| 721 | .Lv15: vxor v19,v19,v15 |
|---|
| 722 | .Lv14: vxor v20,v20,v14 |
|---|
| 723 | .Lv13: vxor v19,v19,v13 |
|---|
| 724 | .Lv12: vxor v20,v20,v12 |
|---|
| 725 | .Lv11: vxor v19,v19,v11 |
|---|
| 726 | .Lv10: vxor v20,v20,v10 |
|---|
| 727 | .Lv9: vxor v19,v19,v9 |
|---|
| 728 | .Lv8: vxor v20,v20,v8 |
|---|
| 729 | .Lv7: vxor v19,v19,v7 |
|---|
| 730 | .Lv6: vxor v20,v20,v6 |
|---|
| 731 | .Lv5: vxor v19,v19,v5 |
|---|
| 732 | .Lv4: vxor v20,v20,v4 |
|---|
| 733 | .Lv3: vxor v19,v19,v3 |
|---|
| 734 | .Lv2: vxor v20,v20,v2 |
|---|
| 735 | .Lv1: vxor v19,v19,v1 |
|---|
| 736 | .Lv0: vxor v20,v20,v0 |
|---|
| 737 | |
|---|
| 738 | vxor v0,v19,v20 |
|---|
| 739 | |
|---|
| 740 | b .Lbarrett_reduction |
|---|
| 741 | |
|---|
| 742 | .Lzero: |
|---|
| 743 | mr r3,r10 |
|---|
| 744 | b .Lout |
|---|
| 745 | |
|---|
| 746 | FUNC_END(CRC_FUNCTION_NAME) |
|---|
| 747 | |
|---|
