include/asm/edac.h

0001 /*
0002  * PPC EDAC common defs
0003  *
0004  * Author: Dave Jiang <djiang@mvista.com>
0005  *
0006  * 2007 (c) MontaVista Software, Inc. This file is licensed under
0007  * the terms of the GNU General Public License version 2. This program
0008  * is licensed "as is" without any warranty of any kind, whether express
0009  * or implied.
0010  */
0011 #ifndef ASM_EDAC_H
0012 #define ASM_EDAC_H
0013 /*
0014  * ECC atomic, DMA, SMP and interrupt safe scrub function.
0015  * Implements the per arch edac_atomic_scrub() that EDAC use for software
0016  * ECC scrubbing.  It reads memory and then writes back the original
0017  * value, allowing the hardware to detect and correct memory errors.
0018  */
0019 static __inline__ void edac_atomic_scrub(void *va, u32 size)
0020 {
0021     unsigned int *virt_addr = va;
0022     unsigned int temp;
0023     unsigned int i;
0024
0025     for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) {
0026         /* Very carefully read and write to memory atomically
0027          * so we are interrupt, DMA and SMP safe.
0028          */
0029         __asm__ __volatile__ ("\n\
0030                 1:  lwarx   %0,0,%1\n\
0031                     stwcx.  %0,0,%1\n\
0032                     bne-    1b\n\
0033                     isync"
0034                     : "=&r"(temp)
0035                     : "r"(virt_addr)
0036                     : "cr0", "memory");
0037     }
0038 }
0039
0040 #endif