[PATCH v1 0/9] RISC-V: Probe DT extension support using riscv,isa-extensions & riscv,isa-base

Conor Dooley
2023-06-26T11:20:59Z

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. I certainly would not be against putting this
stuff in hwcap.h instead.

Note that riscv,isa will still be used in the absence of the new
properties:
if (!acpi_disabled) {
riscv_fill_hwcap_from_isa_string(isa2hwcap);
} else {
int ret = riscv_fill_hwcap_new(isa2hwcap);
if (ret) {
pr_info("Falling back to deprecated \"riscv,isa\"\n");
riscv_fill_hwcap_from_isa_string(isa2hwcap);
}
}

Also, I could not come up with a good name for the new function,
suggestions welcome on that front for sure.

Cheers,
Conor.

As a side note, I tried some macro fiddling to remove the need for a
\#define for each extension that ends up conflicting a bunch between
different people, but didn't come up with anything I was happy with that
worked. I'll keep tinkering with that.

[1] https://lore.kernel.org/all/20230626-unmarked-atom-70b4d624a386@wendy/

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: 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-riscv@lists.infradead.org
CC: devicetree@vger.kernel.org
CC: linux-kernel@vger.kernel.org

Conor Dooley (8):
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()

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

arch/riscv/include/asm/hwcap.h | 16 +-
arch/riscv/kernel/cpu.c | 149 +++-------
arch/riscv/kernel/cpufeature.c | 508 +++++++++++++++++++++------------
3 files changed, 379 insertions(+), 294 deletions(-)

--
2.40.1