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
39