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
On Fri, Apr 28, 2023 at 12:06:05PM -0700, Evan Green wrote:
>
> 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
>
For the series
Reviewed-by: Andrew Jones <[email protected]>