On Tue, Dec 12, 2023 at 05:31:14PM +0800, Haibo Xu wrote:
Borrow the cpu_relax() definitions from kernel's arch/riscv/include/asm/vdso/processor.h to tools/ for riscv.
Signed-off-by: Haibo Xu haibo1.xu@intel.com
tools/arch/riscv/include/asm/vdso/processor.h | 32 +++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 tools/arch/riscv/include/asm/vdso/processor.h
diff --git a/tools/arch/riscv/include/asm/vdso/processor.h b/tools/arch/riscv/include/asm/vdso/processor.h new file mode 100644 index 000000000000..662aca039848 --- /dev/null +++ b/tools/arch/riscv/include/asm/vdso/processor.h @@ -0,0 +1,32 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef __ASM_VDSO_PROCESSOR_H +#define __ASM_VDSO_PROCESSOR_H
+#ifndef __ASSEMBLY__
+#include <asm-generic/barrier.h>
+static inline void cpu_relax(void) +{ +#ifdef __riscv_muldiv
- int dummy;
- /* In lieu of a halt instruction, induce a long-latency stall. */
- __asm__ __volatile__ ("div %0, %0, zero" : "=r" (dummy));
+#endif
+#ifdef CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE
- /*
* Reduce instruction retirement.* This assumes the PC changes.*/- __asm__ __volatile__ ("pause");
+#else
- /* Encoding of the pause instruction */
- __asm__ __volatile__ (".4byte 0x100000F");
+#endif
- barrier();
+}
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_VDSO_PROCESSOR_H */
2.34.1
Reviewed-by: Andrew Jones ajones@ventanamicro.com