This change detects the presence of Zba and Zbb extensions and exports them per-hart to userspace via the hwprobe mechanism. Glibc can then use these in setting up hwcaps-based library search paths. There's a little bit of extra housekeeping here: the first change adds Zba to the set of extensions the kernel recognizes, and the second change starts tracking ISA features per-hart (in addition to the ANDed mask of features across all harts which the kernel uses to make decisions). Now that we track the ISA information per-hart, we could even fix up /proc/cpuinfo to accurately report extension per-hart, though I've left that out of this series for now. Evan Green (3): RISC-V: Add Zba extension probing RISC-V: Track ISA extensions per hart RISC-V: hwprobe: Expose Zba and Zbb Documentation/riscv/hwprobe.rst | 7 +++++ arch/riscv/include/asm/cpufeature.h | 10 +++++++ arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/include/uapi/asm/hwprobe.h | 2 ++ arch/riscv/kernel/cpu.c | 1 + arch/riscv/kernel/cpufeature.c | 19 ++++++++---- arch/riscv/kernel/sys_riscv.c | 43 ++++++++++++++++++++++----- 7 files changed, 70 insertions(+), 13 deletions(-) -- 2.25.1
