xref: /linux/arch/powerpc/include/asm/edac.h (revision ab52c59103002b49f2455371e4b9c56ba3ef1781)
1 /*
2  * PPC EDAC common defs
3  *
4  * Author: Dave Jiang <djiang@mvista.com>
5  *
6  * 2007 (c) MontaVista Software, Inc. This file is licensed under
7  * the terms of the GNU General Public License version 2. This program
8  * is licensed "as is" without any warranty of any kind, whether express
9  * or implied.
10  */
11 #ifndef ASM_EDAC_H
12 #define ASM_EDAC_H
13 /*
14  * ECC atomic, DMA, SMP and interrupt safe scrub function.
15  * Implements the per arch edac_atomic_scrub() that EDAC use for software
16  * ECC scrubbing.  It reads memory and then writes back the original
17  * value, allowing the hardware to detect and correct memory errors.
18  */
19 static __inline__ void edac_atomic_scrub(void *va, u32 size)
20 {
21 	unsigned int *virt_addr = va;
22 	unsigned int temp;
23 	unsigned int i;
24 
25 	for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) {
26 		/* Very carefully read and write to memory atomically
27 		 * so we are interrupt, DMA and SMP safe.
28 		 */
29 		__asm__ __volatile__ ("\n\
30 				1:	lwarx	%0,0,%1\n\
31 					stwcx.	%0,0,%1\n\
32 					bne-	1b\n\
33 					isync"
34 					: "=&r"(temp)
35 					: "r"(virt_addr)
36 					: "cr0", "memory");
37 	}
38 }
39 
40 #endif
41