diff options
Diffstat (limited to 'sys/contrib/openzfs/module/zfs/vdev_raidz_math_scalar.c')
| -rw-r--r-- | sys/contrib/openzfs/module/zfs/vdev_raidz_math_scalar.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/module/zfs/vdev_raidz_math_scalar.c b/sys/contrib/openzfs/module/zfs/vdev_raidz_math_scalar.c new file mode 100644 index 000000000000..cd742e146ca6 --- /dev/null +++ b/sys/contrib/openzfs/module/zfs/vdev_raidz_math_scalar.c @@ -0,0 +1,337 @@ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + */ + +/* + * Copyright (C) 2016 Gvozden Nešković. All rights reserved. + */ + +#include <sys/vdev_raidz_impl.h> + +/* + * Provide native CPU scalar routines. + * Support 32bit and 64bit CPUs. + */ +#if ((~(0x0ULL)) >> 24) == 0xffULL +#define ELEM_SIZE 4 +typedef uint32_t iv_t; +#elif ((~(0x0ULL)) >> 56) == 0xffULL +#define ELEM_SIZE 8 +typedef uint64_t iv_t; +#endif + +/* + * Vector type used in scalar implementation + * + * The union is expected to be of native CPU register size. Since addition + * uses XOR operation, it can be performed an all byte elements at once. + * Multiplication requires per byte access. + */ +typedef union { + iv_t e; + uint8_t b[ELEM_SIZE]; +} v_t; + +/* + * Precomputed lookup tables for multiplication by a constant + * + * Reconstruction path requires multiplication by a constant factors. Instead of + * performing two step lookup (log & exp tables), a direct lookup can be used + * instead. Multiplication of element 'a' by a constant 'c' is obtained as: + * + * r = vdev_raidz_mul_lt[c_log][a]; + * + * where c_log = vdev_raidz_log2[c]. Log of coefficient factors is used because + * they are faster to obtain while solving the syndrome equations. + * + * PERFORMANCE NOTE: + * Even though the complete lookup table uses 64kiB, only relatively small + * portion of it is used at the same time. Following shows number of accessed + * bytes for different cases: + * - 1 failed disk: 256B (1 mul. coefficient) + * - 2 failed disks: 512B (2 mul. coefficients) + * - 3 failed disks: 1536B (6 mul. coefficients) + * + * Size of actually accessed lookup table regions is only larger for + * reconstruction of 3 failed disks, when compared to traditional log/exp + * method. But since the result is obtained in one lookup step performance is + * doubled. + */ +static uint8_t vdev_raidz_mul_lt[256][256] __attribute__((aligned(256))); + +static void +raidz_init_scalar(void) +{ + int c, i; + for (c = 0; c < 256; c++) + for (i = 0; i < 256; i++) + vdev_raidz_mul_lt[c][i] = gf_mul(c, i); + +} + +#define PREFETCHNTA(ptr, offset) {} +#define PREFETCH(ptr, offset) {} + +#define XOR_ACC(src, acc) acc.e ^= ((v_t *)src)[0].e +#define XOR(src, acc) acc.e ^= src.e +#define ZERO(acc) acc.e = 0 +#define COPY(src, dst) dst = src +#define LOAD(src, val) val = ((v_t *)src)[0] +#define STORE(dst, val) ((v_t *)dst)[0] = val + +/* + * Constants used for optimized multiplication by 2. + */ +static const struct { + iv_t mod; + iv_t mask; + iv_t msb; +} scalar_mul2_consts = { +#if ELEM_SIZE == 8 + .mod = 0x1d1d1d1d1d1d1d1dULL, + .mask = 0xfefefefefefefefeULL, + .msb = 0x8080808080808080ULL, +#else + .mod = 0x1d1d1d1dULL, + .mask = 0xfefefefeULL, + .msb = 0x80808080ULL, +#endif +}; + +#define MUL2_SETUP() {} + +#define MUL2(a) \ +{ \ + iv_t _mask; \ + \ + _mask = (a).e & scalar_mul2_consts.msb; \ + _mask = (_mask << 1) - (_mask >> 7); \ + (a).e = ((a).e << 1) & scalar_mul2_consts.mask; \ + (a).e = (a).e ^ (_mask & scalar_mul2_consts.mod); \ +} + +#define MUL4(a) \ +{ \ + MUL2(a); \ + MUL2(a); \ +} + +#define MUL(c, a) \ +{ \ + const uint8_t *mul_lt = vdev_raidz_mul_lt[c]; \ + switch (ELEM_SIZE) { \ + case 8: \ + a.b[7] = mul_lt[a.b[7]]; \ + a.b[6] = mul_lt[a.b[6]]; \ + a.b[5] = mul_lt[a.b[5]]; \ + a.b[4] = mul_lt[a.b[4]]; \ + /* falls through */ \ + case 4: \ + a.b[3] = mul_lt[a.b[3]]; \ + a.b[2] = mul_lt[a.b[2]]; \ + a.b[1] = mul_lt[a.b[1]]; \ + a.b[0] = mul_lt[a.b[0]]; \ + break; \ + } \ +} + +#define raidz_math_begin() {} +#define raidz_math_end() {} + +#define SYN_STRIDE 1 + +#define ZERO_DEFINE() v_t d0 +#define ZERO_STRIDE 1 +#define ZERO_D d0 + +#define COPY_DEFINE() v_t d0 +#define COPY_STRIDE 1 +#define COPY_D d0 + +#define ADD_DEFINE() v_t d0 +#define ADD_STRIDE 1 +#define ADD_D d0 + +#define MUL_DEFINE() v_t d0 +#define MUL_STRIDE 1 +#define MUL_D d0 + +#define GEN_P_STRIDE 1 +#define GEN_P_DEFINE() v_t p0 +#define GEN_P_P p0 + +#define GEN_PQ_STRIDE 1 +#define GEN_PQ_DEFINE() v_t d0, c0 +#define GEN_PQ_D d0 +#define GEN_PQ_C c0 + +#define GEN_PQR_STRIDE 1 +#define GEN_PQR_DEFINE() v_t d0, c0 +#define GEN_PQR_D d0 +#define GEN_PQR_C c0 + +#define SYN_Q_DEFINE() v_t d0, x0 +#define SYN_Q_D d0 +#define SYN_Q_X x0 + + +#define SYN_R_DEFINE() v_t d0, x0 +#define SYN_R_D d0 +#define SYN_R_X x0 + + +#define SYN_PQ_DEFINE() v_t d0, x0 +#define SYN_PQ_D d0 +#define SYN_PQ_X x0 + + +#define REC_PQ_STRIDE 1 +#define REC_PQ_DEFINE() v_t x0, y0, t0 +#define REC_PQ_X x0 +#define REC_PQ_Y y0 +#define REC_PQ_T t0 + + +#define SYN_PR_DEFINE() v_t d0, x0 +#define SYN_PR_D d0 +#define SYN_PR_X x0 + +#define REC_PR_STRIDE 1 +#define REC_PR_DEFINE() v_t x0, y0, t0 +#define REC_PR_X x0 +#define REC_PR_Y y0 +#define REC_PR_T t0 + + +#define SYN_QR_DEFINE() v_t d0, x0 +#define SYN_QR_D d0 +#define SYN_QR_X x0 + + +#define REC_QR_STRIDE 1 +#define REC_QR_DEFINE() v_t x0, y0, t0 +#define REC_QR_X x0 +#define REC_QR_Y y0 +#define REC_QR_T t0 + + +#define SYN_PQR_DEFINE() v_t d0, x0 +#define SYN_PQR_D d0 +#define SYN_PQR_X x0 + +#define REC_PQR_STRIDE 1 +#define REC_PQR_DEFINE() v_t x0, y0, z0, xs0, ys0 +#define REC_PQR_X x0 +#define REC_PQR_Y y0 +#define REC_PQR_Z z0 +#define REC_PQR_XS xs0 +#define REC_PQR_YS ys0 + +#include "vdev_raidz_math_impl.h" + +DEFINE_GEN_METHODS(scalar); +DEFINE_REC_METHODS(scalar); + +boolean_t +raidz_will_scalar_work(void) +{ + return (B_TRUE); /* always */ +} + +const raidz_impl_ops_t vdev_raidz_scalar_impl = { + .init = raidz_init_scalar, + .fini = NULL, + .gen = RAIDZ_GEN_METHODS(scalar), + .rec = RAIDZ_REC_METHODS(scalar), + .is_supported = &raidz_will_scalar_work, + .name = "scalar" +}; + +/* Powers of 2 in the RAID-Z Galois field. */ +const uint8_t vdev_raidz_pow2[256] __attribute__((aligned(256))) = { + 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, + 0x1d, 0x3a, 0x74, 0xe8, 0xcd, 0x87, 0x13, 0x26, + 0x4c, 0x98, 0x2d, 0x5a, 0xb4, 0x75, 0xea, 0xc9, + 0x8f, 0x03, 0x06, 0x0c, 0x18, 0x30, 0x60, 0xc0, + 0x9d, 0x27, 0x4e, 0x9c, 0x25, 0x4a, 0x94, 0x35, + 0x6a, 0xd4, 0xb5, 0x77, 0xee, 0xc1, 0x9f, 0x23, + 0x46, 0x8c, 0x05, 0x0a, 0x14, 0x28, 0x50, 0xa0, + 0x5d, 0xba, 0x69, 0xd2, 0xb9, 0x6f, 0xde, 0xa1, + 0x5f, 0xbe, 0x61, 0xc2, 0x99, 0x2f, 0x5e, 0xbc, + 0x65, 0xca, 0x89, 0x0f, 0x1e, 0x3c, 0x78, 0xf0, + 0xfd, 0xe7, 0xd3, 0xbb, 0x6b, 0xd6, 0xb1, 0x7f, + 0xfe, 0xe1, 0xdf, 0xa3, 0x5b, 0xb6, 0x71, 0xe2, + 0xd9, 0xaf, 0x43, 0x86, 0x11, 0x22, 0x44, 0x88, + 0x0d, 0x1a, 0x34, 0x68, 0xd0, 0xbd, 0x67, 0xce, + 0x81, 0x1f, 0x3e, 0x7c, 0xf8, 0xed, 0xc7, 0x93, + 0x3b, 0x76, 0xec, 0xc5, 0x97, 0x33, 0x66, 0xcc, + 0x85, 0x17, 0x2e, 0x5c, 0xb8, 0x6d, 0xda, 0xa9, + 0x4f, 0x9e, 0x21, 0x42, 0x84, 0x15, 0x2a, 0x54, + 0xa8, 0x4d, 0x9a, 0x29, 0x52, 0xa4, 0x55, 0xaa, + 0x49, 0x92, 0x39, 0x72, 0xe4, 0xd5, 0xb7, 0x73, + 0xe6, 0xd1, 0xbf, 0x63, 0xc6, 0x91, 0x3f, 0x7e, + 0xfc, 0xe5, 0xd7, 0xb3, 0x7b, 0xf6, 0xf1, 0xff, + 0xe3, 0xdb, 0xab, 0x4b, 0x96, 0x31, 0x62, 0xc4, + 0x95, 0x37, 0x6e, 0xdc, 0xa5, 0x57, 0xae, 0x41, + 0x82, 0x19, 0x32, 0x64, 0xc8, 0x8d, 0x07, 0x0e, + 0x1c, 0x38, 0x70, 0xe0, 0xdd, 0xa7, 0x53, 0xa6, + 0x51, 0xa2, 0x59, 0xb2, 0x79, 0xf2, 0xf9, 0xef, + 0xc3, 0x9b, 0x2b, 0x56, 0xac, 0x45, 0x8a, 0x09, + 0x12, 0x24, 0x48, 0x90, 0x3d, 0x7a, 0xf4, 0xf5, + 0xf7, 0xf3, 0xfb, 0xeb, 0xcb, 0x8b, 0x0b, 0x16, + 0x2c, 0x58, 0xb0, 0x7d, 0xfa, 0xe9, 0xcf, 0x83, + 0x1b, 0x36, 0x6c, 0xd8, 0xad, 0x47, 0x8e, 0x01 +}; + +/* Logs of 2 in the RAID-Z Galois field. */ +const uint8_t vdev_raidz_log2[256] __attribute__((aligned(256))) = { + 0x00, 0x00, 0x01, 0x19, 0x02, 0x32, 0x1a, 0xc6, + 0x03, 0xdf, 0x33, 0xee, 0x1b, 0x68, 0xc7, 0x4b, + 0x04, 0x64, 0xe0, 0x0e, 0x34, 0x8d, 0xef, 0x81, + 0x1c, 0xc1, 0x69, 0xf8, 0xc8, 0x08, 0x4c, 0x71, + 0x05, 0x8a, 0x65, 0x2f, 0xe1, 0x24, 0x0f, 0x21, + 0x35, 0x93, 0x8e, 0xda, 0xf0, 0x12, 0x82, 0x45, + 0x1d, 0xb5, 0xc2, 0x7d, 0x6a, 0x27, 0xf9, 0xb9, + 0xc9, 0x9a, 0x09, 0x78, 0x4d, 0xe4, 0x72, 0xa6, + 0x06, 0xbf, 0x8b, 0x62, 0x66, 0xdd, 0x30, 0xfd, + 0xe2, 0x98, 0x25, 0xb3, 0x10, 0x91, 0x22, 0x88, + 0x36, 0xd0, 0x94, 0xce, 0x8f, 0x96, 0xdb, 0xbd, + 0xf1, 0xd2, 0x13, 0x5c, 0x83, 0x38, 0x46, 0x40, + 0x1e, 0x42, 0xb6, 0xa3, 0xc3, 0x48, 0x7e, 0x6e, + 0x6b, 0x3a, 0x28, 0x54, 0xfa, 0x85, 0xba, 0x3d, + 0xca, 0x5e, 0x9b, 0x9f, 0x0a, 0x15, 0x79, 0x2b, + 0x4e, 0xd4, 0xe5, 0xac, 0x73, 0xf3, 0xa7, 0x57, + 0x07, 0x70, 0xc0, 0xf7, 0x8c, 0x80, 0x63, 0x0d, + 0x67, 0x4a, 0xde, 0xed, 0x31, 0xc5, 0xfe, 0x18, + 0xe3, 0xa5, 0x99, 0x77, 0x26, 0xb8, 0xb4, 0x7c, + 0x11, 0x44, 0x92, 0xd9, 0x23, 0x20, 0x89, 0x2e, + 0x37, 0x3f, 0xd1, 0x5b, 0x95, 0xbc, 0xcf, 0xcd, + 0x90, 0x87, 0x97, 0xb2, 0xdc, 0xfc, 0xbe, 0x61, + 0xf2, 0x56, 0xd3, 0xab, 0x14, 0x2a, 0x5d, 0x9e, + 0x84, 0x3c, 0x39, 0x53, 0x47, 0x6d, 0x41, 0xa2, + 0x1f, 0x2d, 0x43, 0xd8, 0xb7, 0x7b, 0xa4, 0x76, + 0xc4, 0x17, 0x49, 0xec, 0x7f, 0x0c, 0x6f, 0xf6, + 0x6c, 0xa1, 0x3b, 0x52, 0x29, 0x9d, 0x55, 0xaa, + 0xfb, 0x60, 0x86, 0xb1, 0xbb, 0xcc, 0x3e, 0x5a, + 0xcb, 0x59, 0x5f, 0xb0, 0x9c, 0xa9, 0xa0, 0x51, + 0x0b, 0xf5, 0x16, 0xeb, 0x7a, 0x75, 0x2c, 0xd7, + 0x4f, 0xae, 0xd5, 0xe9, 0xe6, 0xe7, 0xad, 0xe8, + 0x74, 0xd6, 0xf4, 0xea, 0xa8, 0x50, 0x58, 0xaf, +}; 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