lib/raid/raid6/x86/recov_ssse3.c

Source file repositories/reference/linux-study-clean/lib/raid/raid6/x86/recov_ssse3.c

File Facts

System
Linux kernel
Corpus path
lib/raid/raid6/x86/recov_ssse3.c
Extension
.c
Size
9027 bytes
Lines
322
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) 2012 Intel Corporation
 */

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

static void raid6_2data_recov_ssse3(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) */
	static const u8 __aligned(16) x0f[16] = {
		 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f,
		 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 0x0f, 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();

	asm volatile("movdqa %0,%%xmm7" : : "m" (x0f[0]));

#ifdef CONFIG_X86_64
	asm volatile("movdqa %0,%%xmm6" : : "m" (qmul[0]));
	asm volatile("movdqa %0,%%xmm14" : : "m" (pbmul[0]));
	asm volatile("movdqa %0,%%xmm15" : : "m" (pbmul[16]));
#endif

	/* Now do it... */
	while (bytes) {
#ifdef CONFIG_X86_64
		/* xmm6, xmm14, xmm15 */

		asm volatile("movdqa %0,%%xmm1" : : "m" (q[0]));
		asm volatile("movdqa %0,%%xmm9" : : "m" (q[16]));
		asm volatile("movdqa %0,%%xmm0" : : "m" (p[0]));
		asm volatile("movdqa %0,%%xmm8" : : "m" (p[16]));
		asm volatile("pxor   %0,%%xmm1" : : "m" (dq[0]));
		asm volatile("pxor   %0,%%xmm9" : : "m" (dq[16]));
		asm volatile("pxor   %0,%%xmm0" : : "m" (dp[0]));
		asm volatile("pxor   %0,%%xmm8" : : "m" (dp[16]));

		/* xmm0/8 = px */

		asm volatile("movdqa %xmm6,%xmm4");
		asm volatile("movdqa %0,%%xmm5" : : "m" (qmul[16]));
		asm volatile("movdqa %xmm6,%xmm12");
		asm volatile("movdqa %xmm5,%xmm13");
		asm volatile("movdqa %xmm1,%xmm3");
		asm volatile("movdqa %xmm9,%xmm11");
		asm volatile("movdqa %xmm0,%xmm2"); /* xmm2/10 = px */
		asm volatile("movdqa %xmm8,%xmm10");
		asm volatile("psraw  $4,%xmm1");
		asm volatile("psraw  $4,%xmm9");
		asm volatile("pand   %xmm7,%xmm3");
		asm volatile("pand   %xmm7,%xmm11");
		asm volatile("pand   %xmm7,%xmm1");
		asm volatile("pand   %xmm7,%xmm9");
		asm volatile("pshufb %xmm3,%xmm4");
		asm volatile("pshufb %xmm11,%xmm12");
		asm volatile("pshufb %xmm1,%xmm5");
		asm volatile("pshufb %xmm9,%xmm13");

Annotation

Implementation Notes