[PATCH] riscv: Make sure toolchain supports zba before using zba instructions

[Alexandre Ghiti]

Old toolchain like gcc 8.5.0 does not support zba, so we must check that
the toolchain supports this extension before using it in the kernel.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202503281836.8pntHm6I-lkp@xxxxxxxxx/
Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx>
---
 arch/riscv/Kconfig                     | 8 ++++++++
 arch/riscv/include/asm/runtime-const.h | 5 +++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 0d8def968a7e..ae6303f15b28 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -735,6 +735,14 @@ config TOOLCHAIN_HAS_VECTOR_CRYPTO
 	def_bool $(as-instr, .option arch$(comma) +v$(comma) +zvkb)
 	depends on AS_HAS_OPTION_ARCH
 
+config TOOLCHAIN_HAS_ZBA
+	bool
+	default y
+	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zba)
+	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zba)
+	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
+	depends on AS_HAS_OPTION_ARCH
+
 config RISCV_ISA_ZBA
 	bool "Zba extension support for bit manipulation instructions"
 	default y
diff --git a/arch/riscv/include/asm/runtime-const.h b/arch/riscv/include/asm/runtime-const.h
index ea2e49c7149c..c07d049fdd5d 100644
--- a/arch/riscv/include/asm/runtime-const.h
+++ b/arch/riscv/include/asm/runtime-const.h
@@ -77,7 +77,8 @@
 	".long 1b - .\n\t"					\
 	".popsection"						\
 
-#if defined(CONFIG_RISCV_ISA_ZBA) && defined(CONFIG_RISCV_ISA_ZBKB)
+#if defined(CONFIG_RISCV_ISA_ZBA) && defined(CONFIG_TOOLCHAIN_HAS_ZBA)	\
+	&& defined(CONFIG_RISCV_ISA_ZBKB)
 #define runtime_const_ptr(sym)						\
 ({									\
 	typeof(sym) __ret, __tmp;					\
@@ -93,7 +94,7 @@
 		: [__ret] "=r" (__ret), [__tmp] "=r" (__tmp));		\
 	__ret;								\
 })
-#elif defined(CONFIG_RISCV_ISA_ZBA)
+#elif defined(CONFIG_RISCV_ISA_ZBA) && defined(CONFIG_TOOLCHAIN_HAS_ZBA)
 #define runtime_const_ptr(sym)						\
 ({									\
 	typeof(sym) __ret, __tmp;					\
-- 
2.39.2