| Message ID | 7b633cc441f5133608597463301fef122f5174d3.1702371136.git.haibo1.xu@intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | RISCV: Add kvm Sstc timer selftests | expand |
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>
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 */
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