arch/parisc/include/asm/prefetch.h

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