zfs-builds-mm/zfs-0.8.2/module/zcommon/zfs_fletcher_intel.c

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2019-10-24 23:13:56 +02:00
/*
* Implement fast Fletcher4 with AVX2 instructions. (x86_64)
*
* Use the 256-bit AVX2 SIMD instructions and registers to compute
* Fletcher4 in four incremental 64-bit parallel accumulator streams,
* and then combine the streams to form the final four checksum words.
*
* Copyright (C) 2015 Intel Corporation.
*
* Authors:
* James Guilford <james.guilford@intel.com>
* Jinshan Xiong <jinshan.xiong@intel.com>
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* 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.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#if defined(HAVE_AVX) && defined(HAVE_AVX2)
#include <linux/simd_x86.h>
#include <sys/spa_checksum.h>
#include <sys/strings.h>
#include <zfs_fletcher.h>
static void
fletcher_4_avx2_init(fletcher_4_ctx_t *ctx)
{
bzero(ctx->avx, 4 * sizeof (zfs_fletcher_avx_t));
}
static void
fletcher_4_avx2_fini(fletcher_4_ctx_t *ctx, zio_cksum_t *zcp)
{
uint64_t A, B, C, D;
A = ctx->avx[0].v[0] + ctx->avx[0].v[1] +
ctx->avx[0].v[2] + ctx->avx[0].v[3];
B = 0 - ctx->avx[0].v[1] - 2 * ctx->avx[0].v[2] - 3 * ctx->avx[0].v[3] +
4 * ctx->avx[1].v[0] + 4 * ctx->avx[1].v[1] + 4 * ctx->avx[1].v[2] +
4 * ctx->avx[1].v[3];
C = ctx->avx[0].v[2] + 3 * ctx->avx[0].v[3] - 6 * ctx->avx[1].v[0] -
10 * ctx->avx[1].v[1] - 14 * ctx->avx[1].v[2] -
18 * ctx->avx[1].v[3] + 16 * ctx->avx[2].v[0] +
16 * ctx->avx[2].v[1] + 16 * ctx->avx[2].v[2] +
16 * ctx->avx[2].v[3];
D = 0 - ctx->avx[0].v[3] + 4 * ctx->avx[1].v[0] +
10 * ctx->avx[1].v[1] + 20 * ctx->avx[1].v[2] +
34 * ctx->avx[1].v[3] - 48 * ctx->avx[2].v[0] -
64 * ctx->avx[2].v[1] - 80 * ctx->avx[2].v[2] -
96 * ctx->avx[2].v[3] + 64 * ctx->avx[3].v[0] +
64 * ctx->avx[3].v[1] + 64 * ctx->avx[3].v[2] +
64 * ctx->avx[3].v[3];
ZIO_SET_CHECKSUM(zcp, A, B, C, D);
}
#define FLETCHER_4_AVX2_RESTORE_CTX(ctx) \
{ \
asm volatile("vmovdqu %0, %%ymm0" :: "m" ((ctx)->avx[0])); \
asm volatile("vmovdqu %0, %%ymm1" :: "m" ((ctx)->avx[1])); \
asm volatile("vmovdqu %0, %%ymm2" :: "m" ((ctx)->avx[2])); \
asm volatile("vmovdqu %0, %%ymm3" :: "m" ((ctx)->avx[3])); \
}
#define FLETCHER_4_AVX2_SAVE_CTX(ctx) \
{ \
asm volatile("vmovdqu %%ymm0, %0" : "=m" ((ctx)->avx[0])); \
asm volatile("vmovdqu %%ymm1, %0" : "=m" ((ctx)->avx[1])); \
asm volatile("vmovdqu %%ymm2, %0" : "=m" ((ctx)->avx[2])); \
asm volatile("vmovdqu %%ymm3, %0" : "=m" ((ctx)->avx[3])); \
}
static void
fletcher_4_avx2_native(fletcher_4_ctx_t *ctx, const void *buf, uint64_t size)
{
const uint64_t *ip = buf;
const uint64_t *ipend = (uint64_t *)((uint8_t *)ip + size);
kfpu_begin();
FLETCHER_4_AVX2_RESTORE_CTX(ctx);
for (; ip < ipend; ip += 2) {
asm volatile("vpmovzxdq %0, %%ymm4"::"m" (*ip));
asm volatile("vpaddq %ymm4, %ymm0, %ymm0");
asm volatile("vpaddq %ymm0, %ymm1, %ymm1");
asm volatile("vpaddq %ymm1, %ymm2, %ymm2");
asm volatile("vpaddq %ymm2, %ymm3, %ymm3");
}
FLETCHER_4_AVX2_SAVE_CTX(ctx);
asm volatile("vzeroupper");
kfpu_end();
}
static void
fletcher_4_avx2_byteswap(fletcher_4_ctx_t *ctx, const void *buf, uint64_t size)
{
static const zfs_fletcher_avx_t mask = {
.v = { 0xFFFFFFFF00010203, 0xFFFFFFFF08090A0B,
0xFFFFFFFF00010203, 0xFFFFFFFF08090A0B }
};
const uint64_t *ip = buf;
const uint64_t *ipend = (uint64_t *)((uint8_t *)ip + size);
kfpu_begin();
FLETCHER_4_AVX2_RESTORE_CTX(ctx);
asm volatile("vmovdqu %0, %%ymm5" :: "m" (mask));
for (; ip < ipend; ip += 2) {
asm volatile("vpmovzxdq %0, %%ymm4"::"m" (*ip));
asm volatile("vpshufb %ymm5, %ymm4, %ymm4");
asm volatile("vpaddq %ymm4, %ymm0, %ymm0");
asm volatile("vpaddq %ymm0, %ymm1, %ymm1");
asm volatile("vpaddq %ymm1, %ymm2, %ymm2");
asm volatile("vpaddq %ymm2, %ymm3, %ymm3");
}
FLETCHER_4_AVX2_SAVE_CTX(ctx);
asm volatile("vzeroupper");
kfpu_end();
}
static boolean_t fletcher_4_avx2_valid(void)
{
return (zfs_avx_available() && zfs_avx2_available());
}
const fletcher_4_ops_t fletcher_4_avx2_ops = {
.init_native = fletcher_4_avx2_init,
.fini_native = fletcher_4_avx2_fini,
.compute_native = fletcher_4_avx2_native,
.init_byteswap = fletcher_4_avx2_init,
.fini_byteswap = fletcher_4_avx2_fini,
.compute_byteswap = fletcher_4_avx2_byteswap,
.valid = fletcher_4_avx2_valid,
.name = "avx2"
};
#endif /* defined(HAVE_AVX) && defined(HAVE_AVX2) */