MIPS: Add MSA register definitions & access

This patch introduces definitions for the MSA control registers and
functions which allow access to both the control & vector registers. If
the toolchain being used to build the kernel includes support for MSA
then this patch will make use of that support & use MSA instructions
directly. However toolchain support for MSA is very new & far from a
point where it can be reasonably expected that everyone building the
kernel uses a toolchain with support. Thus fallbacks using .word
assembler directives are also provided for now as a temporary measure.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6429/
Patchwork: https://patchwork.linux-mips.org/patch/6607/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 5 insertions, 0 deletions

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 9b8556de9993..1a5b4032cb66 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -119,6 +119,11 @@ cflags-$(CONFIG_CPU_MICROMIPS) += $(call cc-option,-mmicromips)
 cflags-$(CONFIG_SB1XXX_CORELIS) += $(call cc-option,-mno-sched-prolog) \
                                    -fno-omit-frame-pointer
 
+ifeq ($(CONFIG_CPU_HAS_MSA),y)
+toolchain-msa                   := $(call cc-option-yn,-mhard-float -mfp64 -mmsa)
+cflags-$(toolchain-msa)         += -DTOOLCHAIN_SUPPORTS_MSA
+endif
+
 #
 # CPU-dependent compiler/assembler options for optimization.
 #