1/*
 2 * Copyright 2011 Calxeda, Inc.
 3 * Based on PPC version Copyright 2007 MontaVista Software, Inc.
 4 *
 5 * This program is free software; you can redistribute it and/or modify it
 6 * under the terms and conditions of the GNU General Public License,
 7 * version 2, as published by the Free Software Foundation.
 8 *
 9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program.  If not, see <http://www.gnu.org/licenses/>.
16 */
17#ifndef ASM_EDAC_H
18#define ASM_EDAC_H
19/*
20 * ECC atomic, DMA, SMP and interrupt safe scrub function.
21 * Implements the per arch edac_atomic_scrub() that EDAC use for software
22 * ECC scrubbing.  It reads memory and then writes back the original
23 * value, allowing the hardware to detect and correct memory errors.
24 */
25
26static inline void edac_atomic_scrub(void *va, u32 size)
27{
28#if __LINUX_ARM_ARCH__ >= 6
29	unsigned int *virt_addr = va;
30	unsigned int temp, temp2;
31	unsigned int i;
32
33	for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) {
34		/* Very carefully read and write to memory atomically
35		 * so we are interrupt, DMA and SMP safe.
36		 */
37		__asm__ __volatile__("\n"
38			"1:	ldrex	%0, [%2]\n"
39			"	strex	%1, %0, [%2]\n"
40			"	teq	%1, #0\n"
41			"	bne	1b\n"
42			: "=&r"(temp), "=&r"(temp2)
43			: "r"(virt_addr)
44			: "cc");
45	}
46#endif
47}
48
49#endif

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Copyright 2011 Calxeda, Inc.
 4 * Based on PPC version Copyright 2007 MontaVista Software, Inc.
 
 
 
 
 
 
 
 
 
 
 
 
 5 */
 6#ifndef ASM_EDAC_H
 7#define ASM_EDAC_H
 8/*
 9 * ECC atomic, DMA, SMP and interrupt safe scrub function.
10 * Implements the per arch edac_atomic_scrub() that EDAC use for software
11 * ECC scrubbing.  It reads memory and then writes back the original
12 * value, allowing the hardware to detect and correct memory errors.
13 */
14
15static inline void edac_atomic_scrub(void *va, u32 size)
16{
17#if __LINUX_ARM_ARCH__ >= 6
18	unsigned int *virt_addr = va;
19	unsigned int temp, temp2;
20	unsigned int i;
21
22	for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) {
23		/* Very carefully read and write to memory atomically
24		 * so we are interrupt, DMA and SMP safe.
25		 */
26		__asm__ __volatile__("\n"
27			"1:	ldrex	%0, [%2]\n"
28			"	strex	%1, %0, [%2]\n"
29			"	teq	%1, #0\n"
30			"	bne	1b\n"
31			: "=&r"(temp), "=&r"(temp2)
32			: "r"(virt_addr)
33			: "cc");
34	}
35#endif
36}
37
38#endif