lib/raid/raid6/arm/recov_neon.c

Source file repositories/reference/linux-study-clean/lib/raid/raid6/arm/recov_neon.c

File Facts

System
Linux kernel
Corpus path
lib/raid/raid6/arm/recov_neon.c
Extension
.c
Size
2144 bytes
Lines
87
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
 * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
 */

#include <linux/mm.h>
#include <linux/raid/pq.h>
#include <asm/simd.h>
#include "algos.h"
#include "arm/neon.h"

static void raid6_2data_recov_neon(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) */

	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]]];

	scoped_ksimd()
		__raid6_2data_recov_neon(bytes, p, q, dp, dq, pbmul, qmul);
}

static void raid6_datap_recov_neon(int disks, size_t bytes, int faila,
		void **ptrs)
{
	u8 *p, *q, *dq;
	const u8 *qmul;		/* Q multiplier table */

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

	/*
	 * Compute syndrome with zero for the missing data page
	 * Use the dead data page as temporary storage for delta q
	 */
	dq = (u8 *)ptrs[faila];
	ptrs[faila] = page_address(ZERO_PAGE(0));
	ptrs[disks - 1] = dq;

	raid6_gen_syndrome(disks, bytes, ptrs);

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

	/* Now, pick the proper data tables */
	qmul = raid6_vgfmul[raid6_gfinv[raid6_gfexp[faila]]];

	scoped_ksimd()
		__raid6_datap_recov_neon(bytes, p, q, dq, qmul);
}

const struct raid6_recov_calls raid6_recov_neon = {
	.data2		= raid6_2data_recov_neon,
	.datap		= raid6_datap_recov_neon,
	.name		= "neon",
};

Annotation

Implementation Notes