786a767465
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>
48 lines
1.5 KiB
C
48 lines
1.5 KiB
C
/*
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* Copyright 2011 Calxeda, Inc.
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* Based on PPC version Copyright 2007 MontaVista Software, Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef ASM_EDAC_H
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#define ASM_EDAC_H
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/*
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* ECC atomic, DMA, SMP and interrupt safe scrub function.
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* Implements the per arch atomic_scrub() that EDAC use for software
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* ECC scrubbing. It reads memory and then writes back the original
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* value, allowing the hardware to detect and correct memory errors.
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*/
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static inline void atomic_scrub(void *va, u32 size)
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{
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#if __LINUX_ARM_ARCH__ >= 6
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unsigned int *virt_addr = va;
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unsigned int temp, temp2;
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unsigned int i;
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for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) {
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/* Very carefully read and write to memory atomically
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* so we are interrupt, DMA and SMP safe.
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*/
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__asm__ __volatile__("\n"
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"1: ldrex %0, [%2]\n"
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" strex %1, %0, [%2]\n"
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" teq %1, #0\n"
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" bne 1b\n"
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: "=&r"(temp), "=&r"(temp2)
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: "r"(virt_addr)
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: "cc");
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}
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#endif
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}
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#endif
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