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 26 static 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 50