[POWERPC] EDAC ECC software scrubber

/*

 * PPC EDAC common defs

 *

 * Author: Dave Jiang <djiang@mvista.com>

 *

 * 2007 (c) MontaVista Software, Inc. This file is licensed under

 * the terms of the GNU General Public License version 2. This program

 * is licensed "as is" without any warranty of any kind, whether express

 * or implied.

 */

#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)

{

	unsigned int *virt_addr = va;

	unsigned int temp;

	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:	lwarx	%0,0,%1\n\

					stwcx.	%0,0,%1\n\

					bne-	1b\n\

					isync"

					: "=&r"(temp)

					: "r"(virt_addr)

					: "cr0", "memory");

	}

}

#endif