| Rob Herring | 786a767 | 2011-12-09 17:58:35 +0100 | [diff] [blame] | 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 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 | static inline void atomic_scrub(void *va, u32 size) |
| 26 | { |
| 27 | #if __LINUX_ARM_ARCH__ >= 6 |
| 28 | unsigned int *virt_addr = va; |
| 29 | unsigned int temp, temp2; |
| 30 | unsigned int i; |
| 31 | |
| 32 | for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) { |
| 33 | /* Very carefully read and write to memory atomically |
| 34 | * so we are interrupt, DMA and SMP safe. |
| 35 | */ |
| 36 | __asm__ __volatile__("\n" |
| 37 | "1: ldrex %0, [%2]\n" |
| 38 | " strex %1, %0, [%2]\n" |
| 39 | " teq %1, #0\n" |
| 40 | " bne 1b\n" |
| 41 | : "=&r"(temp), "=&r"(temp2) |
| 42 | : "r"(virt_addr) |
| 43 | : "cc"); |
| 44 | } |
| 45 | #endif |
| 46 | } |
| 47 | |
| 48 | #endif |