diff options
author | Rob Herring <rob.herring@calxeda.com> | 2011-12-09 17:58:35 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-12-11 08:35:50 +0000 |
commit | 786a767465b12cb4c1a45421b12fbf6bff45b0ea (patch) | |
tree | 782492ca819b0176fca17e1be242f01bdf4afd65 /arch/arm/include/asm/edac.h | |
parent | 8878a539ff19a43cf3729e7562cd528f490246ae (diff) | |
download | linux-786a767465b12cb4c1a45421b12fbf6bff45b0ea.tar.bz2 |
ARM: 7201/1: add EDAC atomic_scrub function
Add support for architecture specific EDAC atomic_scrub to ARM. Only ARMv6+
is implemented as ldrex/strex instructions are needed. Supporting EDAC on
ARMv5 or earlier is unlikely at this point anyway.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/include/asm/edac.h')
-rw-r--r-- | arch/arm/include/asm/edac.h | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/arm/include/asm/edac.h b/arch/arm/include/asm/edac.h new file mode 100644 index 000000000000..0df7a2c1fc3d --- /dev/null +++ b/arch/arm/include/asm/edac.h @@ -0,0 +1,48 @@ +/* + * 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 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 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 |