root/tools/perf/bench/mem-memcpy-x86-64-lib.c

DEFINITIONS

1. mcsafe_handle_tail

   1 /*
   2  * From code in arch/x86/lib/usercopy_64.c, copied to keep tools/ copy
   3  * of the kernel's arch/x86/lib/memcpy_64.s used in 'perf bench mem memcpy'
   4  * happy.
   5  */
   6 #include <linux/types.h>
   7 
   8 unsigned long __memcpy_mcsafe(void *dst, const void *src, size_t cnt);
   9 unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len);
  10 
  11 unsigned long mcsafe_handle_tail(char *to, char *from, unsigned len)
  12 {
  13         for (; len; --len, to++, from++) {
  14                 /*
  15                  * Call the assembly routine back directly since
  16                  * memcpy_mcsafe() may silently fallback to memcpy.
  17                  */
  18                 unsigned long rem = __memcpy_mcsafe(to, from, 1);
  19 
  20                 if (rem)
  21                         break;
  22         }
  23         return len;
  24 }