Re: [PATCH 2/9] RISC-V: Detect AIA CSRs from ISA string

Conor Dooley
2022-11-13T14:20:18Z

On Fri, Nov 11, 2022 at 10:12:00AM +0530, Anup Patel wrote:
> We have two extension names for AIA ISA support: Smaia (M-mode AIA CSRs)
> and Ssaia (S-mode AIA CSRs).
>
> We extend the ISA string parsing to detect Smaia and Ssaia extensions.
>
> Signed-off-by: Anup Patel <apatel@ventanamicro.com>
> ---
> arch/riscv/include/asm/hwcap.h | 8 ++++++++
> arch/riscv/kernel/cpu.c | 2 ++
> arch/riscv/kernel/cpufeature.c | 2 ++
> 3 files changed, 12 insertions(+)
>
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index b22525290073..06314220284f 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -59,9 +59,17 @@ enum riscv_isa_ext_id {
> RISCV_ISA_EXT_ZIHINTPAUSE,
> RISCV_ISA_EXT_SSTC,
> RISCV_ISA_EXT_SVINVAL,
> + RISCV_ISA_EXT_SSAIA,
> + RISCV_ISA_EXT_SMAIA,
> RISCV_ISA_EXT_ID_MAX = RISCV_ISA_EXT_MAX,
> };
>
> +#ifdef CONFIG_RISCV_M_MODE
> +#define RISCV_ISA_EXT_SxAIA RISCV_ISA_EXT_SMAIA
> +#else
> +#define RISCV_ISA_EXT_SxAIA RISCV_ISA_EXT_SSAIA
> +#endif
> +
> /*
> * This enum represents the logical ID for each RISC-V ISA extension static
> * keys. We can use static key to optimize code path if some ISA extensions
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index 852ecccd8920..3c84680c2289 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -138,6 +138,8 @@ device_initcall(riscv_cpuinfo_init);
> * extensions by an underscore.
> */
> static struct riscv_isa_ext_data isa_ext_arr[] = {
> + __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
> + __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),

Trivially minor question: Is there a reason you added these before
after svinval elsewhere but before it here?

> __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
> __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
> __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 694267d1fe81..e6d750d088ab 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -205,6 +205,8 @@ void __init riscv_fill_hwcap(void)
> SET_ISA_EXT_MAP("zihintpause", RISCV_ISA_EXT_ZIHINTPAUSE);
> SET_ISA_EXT_MAP("sstc", RISCV_ISA_EXT_SSTC);
> SET_ISA_EXT_MAP("svinval", RISCV_ISA_EXT_SVINVAL);
> + SET_ISA_EXT_MAP("smaia", RISCV_ISA_EXT_SMAIA);
> + SET_ISA_EXT_MAP("ssaia", RISCV_ISA_EXT_SSAIA);
> }
> #undef SET_ISA_EXT_MAP
> }
> --
> 2.34.1
>