[PATCH v4 4/7] riscv: hwprobe: Add MIPS vendor extension probing

[Alexandre Ghiti]

On 6/25/25 16:20, Aleksa Paunovic via B4 Relay wrote:
> From: Aleksa Paunovic <aleksa.paunovic at htecgroup.com>
>
> Add a new hwprobe key "RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0" which allows
> userspace to probe for the new xmipsexectl vendor extension.
>
> Signed-off-by: Aleksa Paunovic <aleksa.paunovic at htecgroup.com>
> ---
>   arch/riscv/include/asm/hwprobe.h                   |  3 ++-
>   .../include/asm/vendor_extensions/mips_hwprobe.h   | 23 ++++++++++++++++++++++
>   arch/riscv/include/uapi/asm/hwprobe.h              |  1 +
>   arch/riscv/include/uapi/asm/vendor/mips.h          |  3 +++
>   arch/riscv/kernel/sys_hwprobe.c                    |  4 ++++
>   arch/riscv/kernel/vendor_extensions/Makefile       |  1 +
>   arch/riscv/kernel/vendor_extensions/mips_hwprobe.c | 22 +++++++++++++++++++++
>   7 files changed, 56 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
> index 7fe0a379474ae2c64d300d6fee4a012173f6a6d7..948d2b34e94e84e4c2c351ffe91f4b3afcefc3f7 100644
> --- a/arch/riscv/include/asm/hwprobe.h
> +++ b/arch/riscv/include/asm/hwprobe.h
> @@ -8,7 +8,7 @@
>   
>   #include <uapi/asm/hwprobe.h>
>   
> -#define RISCV_HWPROBE_MAX_KEY 13
> +#define RISCV_HWPROBE_MAX_KEY 14
>   
>   static inline bool riscv_hwprobe_key_is_valid(__s64 key)
>   {
> @@ -22,6 +22,7 @@ static inline bool hwprobe_key_is_bitmask(__s64 key)
>   	case RISCV_HWPROBE_KEY_IMA_EXT_0:
>   	case RISCV_HWPROBE_KEY_CPUPERF_0:
>   	case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0:
> +	case RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0:
>   	case RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0:
>   		return true;
>   	}
> diff --git a/arch/riscv/include/asm/vendor_extensions/mips_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/mips_hwprobe.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..0af8c07c22f293b5f772709f774de78dd60c7f39
> --- /dev/null
> +++ b/arch/riscv/include/asm/vendor_extensions/mips_hwprobe.h
> @@ -0,0 +1,23 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/*
> + * Copyright (C) 2025 MIPS.
> + */
> +
> +#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_HWPROBE_H_
> +#define _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_HWPROBE_H_
> +
> +#include <linux/cpumask.h>
> +#include <uapi/asm/hwprobe.h>
> +
> +


2 newlines here ^


> +#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_MIPS
> +void hwprobe_isa_vendor_ext_mips_0(struct riscv_hwprobe *pair, const struct cpumask *cpus);
> +#else
> +static inline void hwprobe_isa_vendor_ext_mips_0(struct riscv_hwprobe *pair,
> +						 const struct cpumask *cpus)
> +{
> +	pair->value = 0;
> +}
> +#endif
> +
> +#endif // _ASM_RISCV_VENDOR_EXTENSIONS_MIPS_HWPROBE_H_
> diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
> index aaf6ad97049931381f9542bb9316c873ec6ab9f6..5d30a4fae37a82ef4d968d20b187420772ad8946 100644
> --- a/arch/riscv/include/uapi/asm/hwprobe.h
> +++ b/arch/riscv/include/uapi/asm/hwprobe.h
> @@ -106,6 +106,7 @@ struct riscv_hwprobe {
>   #define RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0	11
>   #define RISCV_HWPROBE_KEY_ZICBOM_BLOCK_SIZE	12
>   #define RISCV_HWPROBE_KEY_VENDOR_EXT_SIFIVE_0	13
> +#define RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0	14
>   /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
>   
>   /* Flags */
> diff --git a/arch/riscv/include/uapi/asm/vendor/mips.h b/arch/riscv/include/uapi/asm/vendor/mips.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..11d41651178233a5f06ab9541ea0506d9883aa19
> --- /dev/null
> +++ b/arch/riscv/include/uapi/asm/vendor/mips.h
> @@ -0,0 +1,3 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +
> +#define RISCV_HWPROBE_VENDOR_EXT_XMIPSEXECTL	(1 << 0)
> diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
> index 0b170e18a2beba576f4f8787d6ef6aa67c5c3d0e..6c73e167ef4ccc7f99dd2793acde2595fffdcbad 100644
> --- a/arch/riscv/kernel/sys_hwprobe.c
> +++ b/arch/riscv/kernel/sys_hwprobe.c
> @@ -15,6 +15,7 @@
>   #include <asm/uaccess.h>
>   #include <asm/unistd.h>
>   #include <asm/vector.h>
> +#include <asm/vendor_extensions/mips_hwprobe.h>
>   #include <asm/vendor_extensions/sifive_hwprobe.h>
>   #include <asm/vendor_extensions/thead_hwprobe.h>
>   #include <vdso/vsyscall.h>
> @@ -309,6 +310,9 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
>   	case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0:
>   		hwprobe_isa_vendor_ext_thead_0(pair, cpus);
>   		break;
> +	case RISCV_HWPROBE_KEY_VENDOR_EXT_MIPS_0:
> +		hwprobe_isa_vendor_ext_mips_0(pair, cpus);
> +		break;
>   
>   	/*
>   	 * For forward compatibility, unknown keys don't fail the whole
> diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
> index ccad4ebafb43412e72e654da3bdb9face53b80c6..bf116c82b6bdb3aee23e27fc0b2a69be7c7a5ccb 100644
> --- a/arch/riscv/kernel/vendor_extensions/Makefile
> +++ b/arch/riscv/kernel/vendor_extensions/Makefile
> @@ -2,6 +2,7 @@
>   
>   obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES)	+= andes.o
>   obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_MIPS)  	+= mips.o
> +obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_MIPS)  	+= mips_hwprobe.o
>   obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE)	+= sifive.o
>   obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_SIFIVE)	+= sifive_hwprobe.o
>   obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD)	+= thead.o
> diff --git a/arch/riscv/kernel/vendor_extensions/mips_hwprobe.c b/arch/riscv/kernel/vendor_extensions/mips_hwprobe.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..43944f2b484af257fa358cda53c12b4d6f54b78b
> --- /dev/null
> +++ b/arch/riscv/kernel/vendor_extensions/mips_hwprobe.c
> @@ -0,0 +1,22 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2025 MIPS.
> + */
> +
> +#include <asm/vendor_extensions/mips.h>
> +#include <asm/vendor_extensions/mips_hwprobe.h>
> +#include <asm/vendor_extensions/vendor_hwprobe.h>
> +
> +#include <linux/cpumask.h>
> +#include <linux/types.h>
> +
> +#include <uapi/asm/hwprobe.h>
> +#include <uapi/asm/vendor/mips.h>
> +
> +void hwprobe_isa_vendor_ext_mips_0(struct riscv_hwprobe *pair,
> +				   const struct cpumask *cpus)
> +{
> +	VENDOR_EXTENSION_SUPPORTED(
> +		pair, cpus, riscv_isa_vendor_ext_list_mips.per_hart_isa_bitmap,
> +		{ VENDOR_EXT_KEY(XMIPSEXECTL); });
> +}


I'll remove the superfluous newline when merging the patchset:

Reviewed-by: Alexandre Ghiti <alexghiti at rivosinc.com>

Thanks,

Alex