riscv: fix detection of toolchain Zicbom support

It is not sufficient to check if a toolchain supports a particular
extension without checking if the linker supports that extension too.
For example, Clang 15 supports Zicbom but GNU bintutils 2.35.2 does
not, leading build errors like so:

riscv64-linux-gnu-ld: -march=rv64i2p0_m2p0_a2p0_c2p0_zicbom1p0_zihintpause2p0: Invalid or unknown z ISA extension: 'zicbom'

Convert CC_HAS_ZICBOM to TOOLCHAIN_HAS_ZICBOM & check if the linker
also supports Zicbom.

Reported-by: Kevin Hilman <khilman@baylibre.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1714
Link: https://storage.kernelci.org/next/master/next-20220920/riscv/defconfig+CONFIG_EFI=n/clang-16/logs/kernel.log
Fixes: 1631ba1259 ("riscv: Add support for non-coherent devices using zicbom extension")
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20221006173520.1785507-2-conor@kernel.org
[Palmer: Check for ld-2.38, not 2.39, as 2.38 no longer errors.]
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
This commit is contained in:
Conor Dooley 2022-10-06 18:35:20 +01:00 committed by Palmer Dabbelt
parent 568035b01c
commit b8c86872d1
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2 changed files with 7 additions and 6 deletions

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@ -401,14 +401,16 @@ config RISCV_ISA_SVPBMT
If you don't know what to do here, say Y.
config CC_HAS_ZICBOM
config TOOLCHAIN_HAS_ZICBOM
bool
default y if 64BIT && $(cc-option,-mabi=lp64 -march=rv64ima_zicbom)
default y if 32BIT && $(cc-option,-mabi=ilp32 -march=rv32ima_zicbom)
default y
depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zicbom)
depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zicbom)
depends on LLD_VERSION >= 150000 || LD_VERSION >= 23800
config RISCV_ISA_ZICBOM
bool "Zicbom extension support for non-coherent DMA operation"
depends on CC_HAS_ZICBOM
depends on TOOLCHAIN_HAS_ZICBOM
depends on !XIP_KERNEL && MMU
select RISCV_DMA_NONCOHERENT
select RISCV_ALTERNATIVE

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@ -57,8 +57,7 @@ toolchain-need-zicsr-zifencei := $(call cc-option-yn, -march=$(riscv-march-y)_zi
riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
# Check if the toolchain supports Zicbom extension
toolchain-supports-zicbom := $(call cc-option-yn, -march=$(riscv-march-y)_zicbom)
riscv-march-$(toolchain-supports-zicbom) := $(riscv-march-y)_zicbom
riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZICBOM) := $(riscv-march-y)_zicbom
# Check if the toolchain supports Zihintpause extension
toolchain-supports-zihintpause := $(call cc-option-yn, -march=$(riscv-march-y)_zihintpause)