riscv: fix detection of toolchain Zicbom support

[ Upstream commit b8c8687 ] 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: ClangBuiltLinux/linux#1714 Link: https://storage.kernelci.org/next/master/next-20220920/riscv/defconfig+CONFIG_EFI=n/clang-16/logs/kernel.log Fixes: 1631ba1 ("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> Signed-off-by: Sasha Levin <sashal@kernel.org>
sirdarckcat · Nov 3, 2022 · 6071dfe · 6071dfe
1 parent ff0f6be
commit 6071dfe
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Showing 2 changed files with 7 additions and 6 deletions.
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
@@ -402,14 +402,16 @@ 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

diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
@@ -59,8 +59,7 @@ 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)