On 11/14/24 10:21, Charlie Jenkins wrote:
Add a new hwprobe key "RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0" which allows userspace to probe for the new RISCV_ISA_VENDOR_EXT_XTHEADVECTOR vendor extension.
Hi Charlie,
How about changing the name of the key from "RISCV_ISA_VENDOR_EXT_XTHEADVECTOR" to "RISCV_HWPROBE_KEY_VENDOR_EXT_0" and use marchid to identify what the vendor is, each vendor will have its own bit definition in this value. So we can avoid adding so many hwprobe keys for each vendor in the future.
I proposed a commit here: https://github.com/cyyself/linux/commit/36390645d85d1ac75dd71172f167719df429...
This new key will allow userspace code to probe for which thead vendor extensions are supported. This API is modeled to be consistent with RISCV_HWPROBE_KEY_IMA_EXT_0. The bitmask returned will have each bit corresponding to a supported thead vendor extension of the cpumask set. Just like RISCV_HWPROBE_KEY_IMA_EXT_0, this allows a userspace program to determine all of the supported thead vendor extensions in one call.
Signed-off-by: Charlie Jenkins charlie@rivosinc.com Reviewed-by: Evan Green evan@rivosinc.com
arch/riscv/include/asm/hwprobe.h | 3 +- .../include/asm/vendor_extensions/thead_hwprobe.h | 19 +++++++++++ .../include/asm/vendor_extensions/vendor_hwprobe.h | 37 ++++++++++++++++++++++ arch/riscv/include/uapi/asm/hwprobe.h | 3 +- arch/riscv/include/uapi/asm/vendor/thead.h | 3 ++ arch/riscv/kernel/sys_hwprobe.c | 5 +++ arch/riscv/kernel/vendor_extensions/Makefile | 1 + .../riscv/kernel/vendor_extensions/thead_hwprobe.c | 19 +++++++++++ 8 files changed, 88 insertions(+), 2 deletions(-)