[PATCH v2 2/2] riscv: Disable misaligned access probe when CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
Eric Biggers
ebiggers at kernel.org
Fri Feb 2 15:01:01 PST 2024
On Thu, Feb 01, 2024 at 03:30:46PM -0800, Charlie Jenkins wrote:
> diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
> index eb3ac304fc42..3a29d8e30e05 100644
> --- a/arch/riscv/include/asm/cpufeature.h
> +++ b/arch/riscv/include/asm/cpufeature.h
> @@ -51,6 +51,7 @@ static inline bool check_unaligned_access_emulated(int cpu)
> static inline void unaligned_emulation_finish(void) {}
> #endif
>
> +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
#ifdef..#else..#endif is more readable than #ifndef..#else..#endif.
> diff --git a/arch/riscv/include/asm/misaligned_access_speed.h b/arch/riscv/include/asm/misaligned_access_speed.h
> new file mode 100644
> index 000000000000..81df2aa6fa6b
> --- /dev/null
> +++ b/arch/riscv/include/asm/misaligned_access_speed.h
This new header file isn't included from anywhere.
> diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile
> index f71910718053..8be7f17da9ab 100644
> --- a/arch/riscv/kernel/Makefile
> +++ b/arch/riscv/kernel/Makefile
> @@ -62,6 +62,9 @@ obj-y += tests/
> obj-$(CONFIG_MMU) += vdso.o vdso/
>
> obj-$(CONFIG_RISCV_MISALIGNED) += traps_misaligned.o
> +ifneq ($(RISCV_EFFICIENT_UNALIGNED_ACCESS), y)
> +obj-y += misaligned_access_speed.o
> +endif
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
> diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
> index a7c56b41efd2..3f1a6edfdb08 100644
> --- a/arch/riscv/kernel/sys_hwprobe.c
> +++ b/arch/riscv/kernel/sys_hwprobe.c
> @@ -149,6 +149,7 @@ static bool hwprobe_ext0_has(const struct cpumask *cpus, unsigned long ext)
>
> static u64 hwprobe_misaligned(const struct cpumask *cpus)
> {
> +#ifndef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
> int cpu;
> u64 perf = -1ULL;
>
> @@ -168,6 +169,9 @@ static u64 hwprobe_misaligned(const struct cpumask *cpus)
> return RISCV_HWPROBE_MISALIGNED_UNKNOWN;
>
> return perf;
> +#else
> + return RISCV_HWPROBE_MISALIGNED_FAST;
> +#endif
#ifdef..#else..#endif is more readable than #ifndef..#else..#endif.
- Eric
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