[PATCH v3 00/20] riscv: report more ISA extensions through hwprobe

From: Clément Léger
Date: Tue Nov 07 2023 - 05:56:13 EST


In order to be able to gather more information about the supported ISA
extensions from userspace using the hwprobe syscall, add more ISA extensions
report. This series adds the following ISA extensions parsing support:

- Zfh[min]
- Zvfh[min]
- Zihintntl
- Zbc
- Zvbb
- Zvbc
- Zvkb
- Zvkg
- Zvkned
- Zvknh[ab]
- Zvksed
- Zvksh
- Zvkn
- Zvknc
- Zvkng
- Zvks
- Zvksc
- Zvksg
- Zvkt
- Zfa
- Zbkb
- Zbkc
- Zbkx
- Zknd
- Zkne
- Zknh
- Zkr
- Zksed
- Zksh
- Zkt

Some of these extensions are actually shorthands for other "sub"
extensions. This series includes a patch from Conor/Evan that adds a way
to specify such "bundled" extensions. When exposing these bundled
extensions to userspace through hwprobe, only the "sub" extensions are
exposed.

In order to test it, one can use qemu and the small hwprobe utility
provided[1]. Run qemu by specifying additional ISA extensions, for
instance:

$ qemu-system-riscv64 -cpu rv64,v=true,zk=true,zvksh=true,zvkned=true
<whatever options you want>

Then, run hwprobe:

$ ./hwprobe
Base system ISA:
- IMA_FD
- C
- V
Supported extensions:
- Zba
- Zbb
- Zbs
- Zbc
- Zbkb
- Zbkc
- Zbkx
- Zknd
- Zkne
- Zknh
- Zkt
- Zvkned
- Zvksh
- Zihintntl
- Zfa

Link: https://github.com/clementleger/hwprobe_dump [1]

---

Changes in V3:
- Rebased on top of origin/master
- Rename bundle_ext to subset_ext since it is used for superset
extensions (Zvbb for instance).
- Add an invalid id for pure lasso extension
- Fix wrong type for check_isa ext, int -> unsigned int
- Use bundled extension for ZVBB/ZVNHB
- Split ZBC hwprobe support from scalar crypto patch
- Fix typos (Evan)
- Added a few Rb: from Evan
- Change Zfh/Zfhmin to Zfh[min] to be more coherent with other commits
- Reword comment about CHECK_ISA_EXT to be more clear

Changes in V2:
- Fix typo in first commit title (fatorize->factorize)
- Add Zfa support
- Fix missing uppercase for Zvkt naming in dt-bindings
- Add Conor Acked-by on dt-bindings commits
- Add scalar crypto support from Conor/Evan.
- Use reporting of bunbled extensions for vector crypto

Clément Léger (19):
riscv: hwprobe: factorize hwprobe ISA extension reporting
riscv: hwprobe: export missing Zbc ISA extension
riscv: hwprobe: add support for scalar crypto ISA extensions
dt-bindings: riscv: add scalar crypto ISA extensions description
riscv: add ISA extension parsing for vector crypto
riscv: hwprobe: export vector crypto ISA extensions
dt-bindings: riscv: add vector crypto ISA extensions description
riscv: add ISA extension parsing for Zfh/Zfh[min]
riscv: hwprobe: export Zfh[min] ISA extensions
dt-bindings: riscv: add Zfh[min] ISA extensions description
riscv: add ISA extension parsing for Zihintntl
riscv: hwprobe: export Zhintntl ISA extension
dt-bindings: riscv: add Zihintntl ISA extension description
riscv: add ISA extension parsing for Zvfh[min]
riscv: hwprobe: export Zvfh[min] ISA extensions
dt-bindings: riscv: add Zvfh[min] ISA extension description
riscv: add ISA extension parsing for Zfa
riscv: hwprobe: export Zfa ISA extension
dt-bindings: riscv: add Zfa ISA extension description

Evan Green (1):
riscv: add ISA extension parsing for scalar crypto

Documentation/arch/riscv/hwprobe.rst | 81 +++++++
.../devicetree/bindings/riscv/extensions.yaml | 210 ++++++++++++++++++
arch/riscv/include/asm/hwcap.h | 36 ++-
arch/riscv/include/uapi/asm/hwprobe.h | 26 +++
arch/riscv/kernel/cpufeature.c | 189 ++++++++++++++--
arch/riscv/kernel/sys_riscv.c | 64 ++++--
6 files changed, 566 insertions(+), 40 deletions(-)

--
2.42.0