arch/powerpc/include/asm/edac.h

   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 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 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