[PATCH v3 00/11] RISC-V: Probe DT extension support using riscv,isa-extensions & riscv,isa-base

Conor Dooley
2023-07-03T10:29:17Z

Hey,

Based on my latest iteration of deprecating riscv,isa [1], here's an
implementation of the new properties for Linux. The first few patches,
up to "RISC-V: split riscv_fill_hwcap() in 3", are all prep work that
further tames some of the extension related code, on top of my already
applied series that cleans up the ISA string parser.
Perhaps "RISC-V: shunt isa_ext_arr to cpufeature.c" is a bit gratuitous,
but I figured a bit of coalescing of extension related data structures
would be a good idea. Note that riscv,isa will still be used in the
absence of the new properties. Palmer suggested adding a Kconfig option
to turn off the fallback for DT, which I have gone and done. It's locked
behind the NONPORTABLE option for good reason.

In v2, I've also come up with a more reasonable name for the new
function I added & fixed up various comments from Drew and Evan.

In v3, there's the new commandline option that Drew suggested. I have
Also picked up a patch from Palmer that adds more helpful prints where
harts fail the checks in riscv_early_of_processor_id(), and I've
sprinkled a few more of those prints in my new additions to the
function.

Cheers,
Conor.

[1] https://lore.kernel.org/all/20230702-eats-scorebook-c951f170d29f@spud

CC: Rob Herring <robh+dt@kernel.org>
CC: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
CC: Paul Walmsley <paul.walmsley@sifive.com>
CC: Palmer Dabbelt <palmer@dabbelt.com>
CC: Albert Ou <aou@eecs.berkeley.edu>
CC: Jonathan Corbet <corbet@lwn.net>
CC: Andrew Jones <ajones@ventanamicro.com>
CC: Heiko Stuebner <heiko.stuebner@vrull.eu>
CC: Evan Green <evan@rivosinc.com>
CC: Sunil V L <sunilvl@ventanamicro.com>
CC: linux-doc@vger.kernel.org
CC: linux-riscv@lists.infradead.org
CC: devicetree@vger.kernel.org
CC: linux-kernel@vger.kernel.org

Conor Dooley (9):
RISC-V: drop a needless check in print_isa_ext()
RISC-V: shunt isa_ext_arr to cpufeature.c
RISC-V: repurpose riscv_isa_ext array in riscv_fill_hwcap()
RISC-V: add missing single letter extension definitions
RISC-V: add single letter extensions to riscv_isa_ext
RISC-V: split riscv_fill_hwcap() in 3
RISC-V: enable extension detection from new properties
RISC-V: try new extension properties in of_early_processor_hartid()
RISC-V: provide Kconfig & commandline options to control parsing
"riscv,isa"

Heiko Stuebner (1):
RISC-V: don't parse dt/acpi isa string to get rv32/rv64

Palmer Dabbelt (1):
RISC-V: Provide a more helpful error message on invalid ISA strings

.../admin-guide/kernel-parameters.txt | 7 +
arch/riscv/Kconfig | 18 +
arch/riscv/include/asm/hwcap.h | 17 +-
arch/riscv/kernel/cpu.c | 177 ++----
arch/riscv/kernel/cpufeature.c | 519 ++++++++++++------
5 files changed, 436 insertions(+), 302 deletions(-)

--
2.40.1