arm64/sme: Provide Kconfig for SME

Now that basline support for the Scalable Matrix Extension (SME) is present
introduce the Kconfig option allowing it to be built. While the feature
registers don't impose a strong requirement for a system with SME to
support SVE at runtime the support for streaming mode SVE is mostly
shared with normal SVE so depend on SVE.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-28-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 57c4c995965f8291bf3c89303bc8c00dc0276dd4..0897984918e8bdd0020f8b16f21878dd43db6275 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1939,6 +1939,17 @@ config ARM64_SVE
          booting the kernel.  If unsure and you are not observing these
          symptoms, you should assume that it is safe to say Y.
 
+config ARM64_SME
+       bool "ARM Scalable Matrix Extension support"
+       default y
+       depends on ARM64_SVE
+       help
+         The Scalable Matrix Extension (SME) is an extension to the AArch64
+         execution state which utilises a substantial subset of the SVE
+         instruction set, together with the addition of new architectural
+         register state capable of holding two dimensional matrix tiles to
+         enable various matrix operations.
+
 config ARM64_MODULE_PLTS
        bool "Use PLTs to allow module memory to spill over into vmalloc area"
        depends on MODULES