LXR linux/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
  23static 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
  36static 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 */
  46