From 00e76e2c6a2bd3976d44d4a1fdd0b7a3c2566607 Mon Sep 17 00:00:00 2001 From: Evan Green Date: Fri, 7 Apr 2023 16:11:00 -0700 Subject: RISC-V: hwprobe: Add support for RISCV_HWPROBE_BASE_BEHAVIOR_IMA We have an implicit set of base behaviors that userspace depends on, which are mostly defined in various ISA specifications. Co-developed-by: Palmer Dabbelt Signed-off-by: Evan Green Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Reviewed-by: Paul Walmsley Link: https://lore.kernel.org/r/20230407231103.2622178-4-evan@rivosinc.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwprobe.h | 2 +- arch/riscv/include/uapi/asm/hwprobe.h | 5 +++++ arch/riscv/kernel/sys_riscv.c | 20 ++++++++++++++++++++ 3 files changed, 26 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h index 6184bbc77256..d717c80a64ff 100644 --- a/arch/riscv/include/asm/hwprobe.h +++ b/arch/riscv/include/asm/hwprobe.h @@ -8,6 +8,6 @@ #include -#define RISCV_HWPROBE_MAX_KEY 2 +#define RISCV_HWPROBE_MAX_KEY 4 #endif diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h index b79be00920db..398e08f7e083 100644 --- a/arch/riscv/include/uapi/asm/hwprobe.h +++ b/arch/riscv/include/uapi/asm/hwprobe.h @@ -20,6 +20,11 @@ struct riscv_hwprobe { #define RISCV_HWPROBE_KEY_MVENDORID 0 #define RISCV_HWPROBE_KEY_MARCHID 1 #define RISCV_HWPROBE_KEY_MIMPID 2 +#define RISCV_HWPROBE_KEY_BASE_BEHAVIOR 3 +#define RISCV_HWPROBE_BASE_BEHAVIOR_IMA (1 << 0) +#define RISCV_HWPROBE_KEY_IMA_EXT_0 4 +#define RISCV_HWPROBE_IMA_FD (1 << 0) +#define RISCV_HWPROBE_IMA_C (1 << 1) /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */ #endif diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index fe8e833ecb2e..5ca567cef142 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -125,6 +126,25 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair, case RISCV_HWPROBE_KEY_MIMPID: hwprobe_arch_id(pair, cpus); break; + /* + * The kernel already assumes that the base single-letter ISA + * extensions are supported on all harts, and only supports the + * IMA base, so just cheat a bit here and tell that to + * userspace. + */ + case RISCV_HWPROBE_KEY_BASE_BEHAVIOR: + pair->value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA; + break; + + case RISCV_HWPROBE_KEY_IMA_EXT_0: + pair->value = 0; + if (has_fpu()) + pair->value |= RISCV_HWPROBE_IMA_FD; + + if (riscv_isa_extension_available(NULL, c)) + pair->value |= RISCV_HWPROBE_IMA_C; + + break; /* * For forward compatibility, unknown keys don't fail the whole -- cgit v1.2.3