LXR linux/arch/arm/include/asm/edac.h

   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