2022-05-23 06:10:39

by Jisheng Zhang

Subject: [PATCH v2 2/2] riscv: switch has_fpu() to the unified static key mechanism

This is to use the unified static key mechanism instead of putting
static key related here and there.

Signed-off-by: Jisheng Zhang <[email protected]>
---
arch/riscv/include/asm/switch_to.h | 4 ++--
arch/riscv/kernel/cpufeature.c | 7 -------
2 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
index 0a3f4f95c555..11463489fec6 100644
--- a/arch/riscv/include/asm/switch_to.h
+++ b/arch/riscv/include/asm/switch_to.h
@@ -8,6 +8,7 @@

#include <linux/jump_label.h>
#include <linux/sched/task_stack.h>
+#include <asm/hwcap.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/csr.h>
@@ -56,10 +57,9 @@ static inline void __switch_to_aux(struct task_struct *prev,
fstate_restore(next, task_pt_regs(next));
}

-extern struct static_key_false cpu_hwcap_fpu;
static __always_inline bool has_fpu(void)
{
- return static_branch_likely(&cpu_hwcap_fpu);
+ return static_branch_likely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_FPU]);
}
#else
static __always_inline bool has_fpu(void) { return false; }
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 89f886b35357..0235391be84b 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -21,9 +21,6 @@ unsigned long elf_hwcap __read_mostly;
/* Host ISA bitmap */
static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;

-#ifdef CONFIG_FPU
-__ro_after_init DEFINE_STATIC_KEY_FALSE(cpu_hwcap_fpu);
-#endif
__ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
EXPORT_SYMBOL(riscv_isa_ext_keys);

@@ -239,8 +236,4 @@ void __init riscv_fill_hwcap(void)
if (j >= 0)
static_branch_enable(&riscv_isa_ext_keys[j]);
}
-#ifdef CONFIG_FPU
- if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D))
- static_branch_enable(&cpu_hwcap_fpu);
-#endif
}
--
2.34.1

2022-05-23 14:43:47

by Atish Patra

Subject: Re: [PATCH v2 2/2] riscv: switch has_fpu() to the unified static key mechanism

On Sun, May 22, 2022 at 8:44 AM Jisheng Zhang <[email protected]> wrote:
>
> This is to use the unified static key mechanism instead of putting
> static key related here and there.
>
> Signed-off-by: Jisheng Zhang <[email protected]>
> ---
> arch/riscv/include/asm/switch_to.h | 4 ++--
> arch/riscv/kernel/cpufeature.c | 7 -------
> 2 files changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
> index 0a3f4f95c555..11463489fec6 100644
> --- a/arch/riscv/include/asm/switch_to.h
> +++ b/arch/riscv/include/asm/switch_to.h
> @@ -8,6 +8,7 @@
>
> #include <linux/jump_label.h>
> #include <linux/sched/task_stack.h>
> +#include <asm/hwcap.h>
> #include <asm/processor.h>
> #include <asm/ptrace.h>
> #include <asm/csr.h>
> @@ -56,10 +57,9 @@ static inline void __switch_to_aux(struct task_struct *prev,
> fstate_restore(next, task_pt_regs(next));
> }
>
> -extern struct static_key_false cpu_hwcap_fpu;
> static __always_inline bool has_fpu(void)
> {
> - return static_branch_likely(&cpu_hwcap_fpu);
> + return static_branch_likely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_FPU]);
> }
> #else
> static __always_inline bool has_fpu(void) { return false; }
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 89f886b35357..0235391be84b 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -21,9 +21,6 @@ unsigned long elf_hwcap __read_mostly;
> /* Host ISA bitmap */
> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>
> -#ifdef CONFIG_FPU
> -__ro_after_init DEFINE_STATIC_KEY_FALSE(cpu_hwcap_fpu);
> -#endif
> __ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> EXPORT_SYMBOL(riscv_isa_ext_keys);
>
> @@ -239,8 +236,4 @@ void __init riscv_fill_hwcap(void)
> if (j >= 0)
> static_branch_enable(&riscv_isa_ext_keys[j]);
> }
> -#ifdef CONFIG_FPU
> - if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D))
> - static_branch_enable(&cpu_hwcap_fpu);
> -#endif
> }
> --
> 2.34.1
>

Reviewed-by: Atish Patra <[email protected]>

--
Regards,
Atish

2022-05-23 15:08:56

by Anup Patel

Subject: Re: [PATCH v2 2/2] riscv: switch has_fpu() to the unified static key mechanism

On Sun, May 22, 2022 at 9:14 PM Jisheng Zhang <[email protected]> wrote:
>
> This is to use the unified static key mechanism instead of putting
> static key related here and there.
>
> Signed-off-by: Jisheng Zhang <[email protected]>

Looks good to me.

Reviewed-by: Anup Patel <[email protected]>

Regards,
Anup

> ---
> arch/riscv/include/asm/switch_to.h | 4 ++--
> arch/riscv/kernel/cpufeature.c | 7 -------
> 2 files changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
> index 0a3f4f95c555..11463489fec6 100644
> --- a/arch/riscv/include/asm/switch_to.h
> +++ b/arch/riscv/include/asm/switch_to.h
> @@ -8,6 +8,7 @@
>
> #include <linux/jump_label.h>
> #include <linux/sched/task_stack.h>
> +#include <asm/hwcap.h>
> #include <asm/processor.h>
> #include <asm/ptrace.h>
> #include <asm/csr.h>
> @@ -56,10 +57,9 @@ static inline void __switch_to_aux(struct task_struct *prev,
> fstate_restore(next, task_pt_regs(next));
> }
>
> -extern struct static_key_false cpu_hwcap_fpu;
> static __always_inline bool has_fpu(void)
> {
> - return static_branch_likely(&cpu_hwcap_fpu);
> + return static_branch_likely(&riscv_isa_ext_keys[RISCV_ISA_EXT_KEY_FPU]);
> }
> #else
> static __always_inline bool has_fpu(void) { return false; }
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 89f886b35357..0235391be84b 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -21,9 +21,6 @@ unsigned long elf_hwcap __read_mostly;
> /* Host ISA bitmap */
> static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
>
> -#ifdef CONFIG_FPU
> -__ro_after_init DEFINE_STATIC_KEY_FALSE(cpu_hwcap_fpu);
> -#endif
> __ro_after_init DEFINE_STATIC_KEY_ARRAY_FALSE(riscv_isa_ext_keys, RISCV_ISA_EXT_KEY_MAX);
> EXPORT_SYMBOL(riscv_isa_ext_keys);
>
> @@ -239,8 +236,4 @@ void __init riscv_fill_hwcap(void)
> if (j >= 0)
> static_branch_enable(&riscv_isa_ext_keys[j]);
> }
> -#ifdef CONFIG_FPU
> - if (elf_hwcap & (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D))
> - static_branch_enable(&cpu_hwcap_fpu);
> -#endif
> }
> --
> 2.34.1
>