lib/raid/raid6/x86/recov_avx512.c

Source file repositories/reference/linux-study-clean/lib/raid/raid6/x86/recov_avx512.c

File Facts

System
Linux kernel
Corpus path
lib/raid/raid6/x86/recov_avx512.c
Extension
.c
Size
9200 bytes
Lines
368
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2016 Intel Corporation
 *
 * Author: Gayatri Kammela <gayatri.kammela@intel.com>
 * Author: Megha Dey <megha.dey@linux.intel.com>
 */

#include <linux/mm.h>
#include <linux/raid/pq.h>
#include <asm/fpu/api.h>
#include "algos.h"

static void raid6_2data_recov_avx512(int disks, size_t bytes, int faila,
				     int failb, void **ptrs)
{
	u8 *p, *q, *dp, *dq;
	const u8 *pbmul;	/* P multiplier table for B data */
	const u8 *qmul;		/* Q multiplier table (for both) */
	const u8 x0f = 0x0f;

	p = (u8 *)ptrs[disks-2];
	q = (u8 *)ptrs[disks-1];

	/*
	 * Compute syndrome with zero for the missing data pages
	 * Use the dead data pages as temporary storage for
	 * delta p and delta q
	 */

	dp = (u8 *)ptrs[faila];
	ptrs[faila] = page_address(ZERO_PAGE(0));
	ptrs[disks-2] = dp;
	dq = (u8 *)ptrs[failb];
	ptrs[failb] = page_address(ZERO_PAGE(0));
	ptrs[disks-1] = dq;

	raid6_gen_syndrome(disks, bytes, ptrs);

	/* Restore pointer table */
	ptrs[faila]   = dp;
	ptrs[failb]   = dq;
	ptrs[disks-2] = p;
	ptrs[disks-1] = q;

	/* Now, pick the proper data tables */
	pbmul = raid6_vgfmul[raid6_gfexi[failb-faila]];
	qmul  = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila] ^
		raid6_gfexp[failb]]];

	kernel_fpu_begin();

	/* zmm0 = x0f[16] */
	asm volatile("vpbroadcastb %0, %%zmm7" : : "m" (x0f));

	while (bytes) {
#ifdef CONFIG_X86_64
		asm volatile("vmovdqa64 %0, %%zmm1\n\t"
			     "vmovdqa64 %1, %%zmm9\n\t"
			     "vmovdqa64 %2, %%zmm0\n\t"
			     "vmovdqa64 %3, %%zmm8\n\t"
			     "vpxorq %4, %%zmm1, %%zmm1\n\t"
			     "vpxorq %5, %%zmm9, %%zmm9\n\t"
			     "vpxorq %6, %%zmm0, %%zmm0\n\t"
			     "vpxorq %7, %%zmm8, %%zmm8"
			     :
			     : "m" (q[0]), "m" (q[64]), "m" (p[0]),
			       "m" (p[64]), "m" (dq[0]), "m" (dq[64]),
			       "m" (dp[0]), "m" (dp[64]));

		/*
		 * 1 = dq[0]  ^ q[0]
		 * 9 = dq[64] ^ q[64]
		 * 0 = dp[0]  ^ p[0]
		 * 8 = dp[64] ^ p[64]
		 */

		asm volatile("vbroadcasti64x2 %0, %%zmm4\n\t"
			     "vbroadcasti64x2 %1, %%zmm5"
			     :
			     : "m" (qmul[0]), "m" (qmul[16]));

		asm volatile("vpsraw $4, %%zmm1, %%zmm3\n\t"
			     "vpsraw $4, %%zmm9, %%zmm12\n\t"
			     "vpandq %%zmm7, %%zmm1, %%zmm1\n\t"
			     "vpandq %%zmm7, %%zmm9, %%zmm9\n\t"
			     "vpandq %%zmm7, %%zmm3, %%zmm3\n\t"
			     "vpandq %%zmm7, %%zmm12, %%zmm12\n\t"
			     "vpshufb %%zmm9, %%zmm4, %%zmm14\n\t"
			     "vpshufb %%zmm1, %%zmm4, %%zmm4\n\t"

Annotation

Implementation Notes