/* * Copyright 2011 Calxeda, Inc. * Based on PPC version Copyright 2007 MontaVista Software, Inc. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program. If not, see <http://www.gnu.org/licenses/>. */ #ifndef ASM_EDAC_H #define ASM_EDAC_H /* * ECC atomic, DMA, SMP and interrupt safe scrub function. * Implements the per arch edac_atomic_scrub() that EDAC use for software * ECC scrubbing. It reads memory and then writes back the original * value, allowing the hardware to detect and correct memory errors. */ static inline void edac_atomic_scrub(void *va, u32 size) { #if __LINUX_ARM_ARCH__ >= 6 unsigned int *virt_addr = va; unsigned int temp, temp2; unsigned int i; for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) { /* Very carefully read and write to memory atomically * so we are interrupt, DMA and SMP safe. */ __asm__ __volatile__("\n" "1: ldrex %0, [%2]\n" " strex %1, %0, [%2]\n" " teq %1, #0\n" " bne 1b\n" : "=&r"(temp), "=&r"(temp2) : "r"(virt_addr) : "cc"); } #endif } #endif |