diff options
Diffstat (limited to 'kernel/arch/parisc/include/asm/prefetch.h')
| -rw-r--r-- | kernel/arch/parisc/include/asm/prefetch.h | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/kernel/arch/parisc/include/asm/prefetch.h b/kernel/arch/parisc/include/asm/prefetch.h new file mode 100644 index 000000000..1ee7c8267 --- /dev/null +++ b/kernel/arch/parisc/include/asm/prefetch.h @@ -0,0 +1,44 @@ +/* + * include/asm-parisc/prefetch.h + * + * PA 2.0 defines data prefetch instructions on page 6-11 of the Kane book. + * In addition, many implementations do hardware prefetching of both + * instructions and data. + * + * PA7300LC (page 14-4 of the ERS) also implements prefetching by a load + * to gr0 but not in a way that Linux can use. If the load would cause an + * interruption (eg due to prefetching 0), it is suppressed on PA2.0 + * processors, but not on 7300LC. + * + */ + +#ifndef __ASM_PARISC_PREFETCH_H +#define __ASM_PARISC_PREFETCH_H + +#ifndef __ASSEMBLY__ +#ifdef CONFIG_PREFETCH + +#define ARCH_HAS_PREFETCH +static inline void prefetch(const void *addr) +{ + __asm__( +#ifndef CONFIG_PA20 + /* Need to avoid prefetch of NULL on PA7300LC */ + " extrw,u,= %0,31,32,%%r0\n" +#endif + " ldw 0(%0), %%r0" : : "r" (addr)); +} + +/* LDD is a PA2.0 addition. */ +#ifdef CONFIG_PA20 +#define ARCH_HAS_PREFETCHW +static inline void prefetchw(const void *addr) +{ + __asm__("ldd 0(%0), %%r0" : : "r" (addr)); +} +#endif /* CONFIG_PA20 */ + +#endif /* CONFIG_PREFETCH */ +#endif /* __ASSEMBLY__ */ + +#endif /* __ASM_PARISC_PROCESSOR_H */ |