lib/raid6/recov_neon.c

/*
 * Copyright (C) 2012 Intel Corporation
 * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 */

#include <linux/raid/pq.h>

#ifdef __KERNEL__
#include <asm/neon.h>
#else
#define kernel_neon_begin()
#define kernel_neon_end()
#define cpu_has_neon()		(1)
#endif

static int raid6_has_neon(void)
{
	return cpu_has_neon();
}

void __raid6_2data_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dp,
			      uint8_t *dq, const uint8_t *pbmul,
			      const uint8_t *qmul);

void __raid6_datap_recov_neon(int bytes, uint8_t *p, uint8_t *q, uint8_t *dq,
			      const uint8_t *qmul);

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] = (void *)raid6_empty_zero_page;
	ptrs[disks - 2] = dp;
	dq = (u8 *)ptrs[failb];
	ptrs[failb] = (void *)raid6_empty_zero_page;
	ptrs[disks - 1] = dq;

	raid6_call.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_neon_begin();
	__raid6_2data_recov_neon(bytes, p, q, dp, dq, pbmul, qmul);
	kernel_neon_end();
}

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] = (void *)raid6_empty_zero_page;
	ptrs[disks - 1] = dq;

	raid6_call.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]]];

	kernel_neon_begin();
	__raid6_datap_recov_neon(bytes, p, q, dq, qmul);
	kernel_neon_end();
}

const struct raid6_recov_calls raid6_recov_neon = {
	.data2		= raid6_2data_recov_neon,
	.datap		= raid6_datap_recov_neon,
	.valid		= raid6_has_neon,
	.name		= "neon",
	.priority	= 10,
};