arch/parisc/include/asm/prefetch.h

   1 /*
   2  * include/asm-parisc/prefetch.h
   3  *
   4  * PA 2.0 defines data prefetch instructions on page 6-11 of the Kane book.
   5  * In addition, many implementations do hardware prefetching of both
   6  * instructions and data.
   7  *
   8  * PA7300LC (page 14-4 of the ERS) also implements prefetching by a load
   9  * to gr0 but not in a way that Linux can use.  If the load would cause an
  10  * interruption (eg due to prefetching 0), it is suppressed on PA2.0
  11  * processors, but not on 7300LC.
  12  *
  13  */
  14
  15 #ifndef __ASM_PARISC_PREFETCH_H
  16 #define __ASM_PARISC_PREFETCH_H
  17
  18 #ifndef __ASSEMBLY__
  19 #ifdef CONFIG_PREFETCH
  20
  21 #define ARCH_HAS_PREFETCH
  22 static inline void prefetch(const void *addr)
  23 {
  24         __asm__(
  25 #ifndef CONFIG_PA20
  26                 /* Need to avoid prefetch of NULL on PA7300LC */
  27                 "       extrw,u,= %0,31,32,%%r0\n"
  28 #endif
  29                 "       ldw 0(%0), %%r0" : : "r" (addr));
  30 }
  31
  32 /* LDD is a PA2.0 addition. */
  33 #ifdef CONFIG_PA20
  34 #define ARCH_HAS_PREFETCHW
  35 static inline void prefetchw(const void *addr)
  36 {
  37         __asm__("ldd 0(%0), %%r0" : : "r" (addr));
  38 }
  39 #endif /* CONFIG_PA20 */
  40
  41 #endif /* CONFIG_PREFETCH */
  42 #endif /* __ASSEMBLY__ */
  43
  44 #endif /* __ASM_PARISC_PROCESSOR_H */