arch/x86/lib/scrub.c

   1 #include <asm/cpufeature.h>
   2 #include <asm/page.h>
   3 #include <asm/processor.h>
   4
   5 void xen_scrub_pages(void *v, unsigned int count)
   6 {
   7         if (likely(cpu_has_xmm2)) {
   8                 unsigned long n = count * (PAGE_SIZE / sizeof(long) / 4);
   9
  10                 for (; n--; v += sizeof(long) * 4)
  11                         asm("movnti %1,(%0)\n\t"
  12                             "movnti %1,%c2(%0)\n\t"
  13                             "movnti %1,2*%c2(%0)\n\t"
  14                             "movnti %1,3*%c2(%0)\n\t"
  15                             : : "r" (v), "r" (0L), "i" (sizeof(long))
  16                             : "memory");
  17                 asm volatile("sfence" : : : "memory");
  18         } else
  19                 for (; count--; v += PAGE_SIZE)
  20                         clear_page(v);
  21 }