Messages in this thread Patch in this message | | | From | wang_yang <> | Subject | [PATCH] RISC-V: Use GCC __builtin_prefetch() to implement prefetch() | Date | Wed, 26 Jul 2023 15:47:32 +0800 |
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GCC's __builtin_prefetch() was introduced a long time ago, all supported GCC versions have it.So this patch is to use it for implementing the prefetch.
RISC-V Cache Management Operation instructions has been supported by GCC last year.you can refer to https://github.com/gcc-mirror/gcc/commit/3df3ca9014f94fe4af07444fea19b4ab29ba8e73 It is worth noting that CPU based on RISC-V should support Zicbop extension.
This has been already done on other architectures (see the commit: https://github.com/torvalds/linux/commit/0453fb3c528c5eb3483441a466b24a4cb409eec5).
Signed-off-by: Wang Yang <yangwang@nj.iscas.ac.cn> --- arch/riscv/include/asm/processor.h | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index c950a8d9edef..f16d4c85ca5b 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -70,6 +70,17 @@ extern void start_thread(struct pt_regs *regs, extern unsigned long __get_wchan(struct task_struct *p); +#define ARCH_HAS_PREFETCH +static inline void prefetch(const void *ptr) +{ + __builtin_prefetch(ptr, 0, 3); +} + +#define ARCH_HAS_PREFETCHW +static inline void prefetchw(const void *ptr) +{ + __builtin_prefetch(ptr, 1, 3); +} static inline void wait_for_interrupt(void) { -- 2.34.1
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