[RFC PATCH 04/13] RISC-V: add TOOLCHAIN_HAS_VECTOR_CRYPTO

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

Add a kconfig symbol that indicates whether the toolchain supports the
vector crypto extensions.  This is needed by the RISC-V crypto code.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 arch/riscv/Kconfig | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 95a2a06acc6a6..bf275a713b1b5 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -526,20 +526,27 @@ config RISCV_ISA_V_DEFAULT_ENABLE
 	  If you don't know what to do here, say Y.
 
 config TOOLCHAIN_HAS_ZBB
 	bool
 	default y
 	depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb)
 	depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb)
 	depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900
 	depends on AS_HAS_OPTION_ARCH
 
+# This symbol indicates that the toolchain supports all v1.0 vector crypto
+# extensions, including Zvk*, Zvbb, and Zvbc.  LLVM added all of these at once.
+# binutils added all except Zvkb, then added Zvkb.  So we just check for Zvkb.
+config TOOLCHAIN_HAS_VECTOR_CRYPTO
+	def_bool $(as-instr, .option arch$(comma) +zvkb)
+	depends on AS_HAS_OPTION_ARCH
+
 config RISCV_ISA_ZBB
 	bool "Zbb extension support for bit manipulation instructions"
 	depends on TOOLCHAIN_HAS_ZBB
 	depends on MMU
 	depends on RISCV_ALTERNATIVE
 	default y
 	help
 	   Adds support to dynamically detect the presence of the ZBB
 	   extension (basic bit manipulation) and enable its usage.
 
-- 
2.43.0