[PATCH -next v17 20/20] riscv: Enable Vector code to be built

Andy Chiu
2023-03-27T16:52:11Z

From: Guo Ren <guoren@linux.alibaba.com>

This patch adds a config which enables vector feature from the kernel
space.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Co-developed-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Suggested-by: Vineet Gupta <vineetg@rivosinc.com>
Suggested-by: Atish Patra <atishp@atishpatra.org>
Co-developed-by: Andy Chiu <andy.chiu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
arch/riscv/Kconfig | 20 ++++++++++++++++++++
arch/riscv/Makefile | 6 +++++-
2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 91d5f2731f06..d95245311bf0 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -443,6 +443,26 @@ config RISCV_ISA_SVPBMT

If you don't know what to do here, say Y.

+config TOOLCHAIN_HAS_V
+ bool
+ default y
+ depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv)
+ depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv)
+ depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
+ depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_V
+ bool "VECTOR extension support"
+ depends on TOOLCHAIN_HAS_V
+ depends on FPU
+ select DYNAMIC_SIGFRAME
+ default y
+ help
+ Say N here if you want to disable all vector related procedure
+ in the kernel.
+
+ If you don't know what to do here, say Y.
+
config TOOLCHAIN_HAS_ZBB
bool
default y
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 6203c3378922..6f32c0ab32e3 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -56,6 +56,7 @@ riscv-march-$(CONFIG_ARCH_RV32I) := rv32ima
riscv-march-$(CONFIG_ARCH_RV64I) := rv64ima
riscv-march-$(CONFIG_FPU) := $(riscv-march-y)fd
riscv-march-$(CONFIG_RISCV_ISA_C) := $(riscv-march-y)c
+riscv-march-$(CONFIG_RISCV_ISA_V) := $(riscv-march-y)v

# Newer binutils versions default to ISA spec version 20191213 which moves some
# instructions from the I extension to the Zicsr and Zifencei extensions.
@@ -65,7 +66,10 @@ riscv-march-$(toolchain-need-zicsr-zifencei) := $(riscv-march-y)_zicsr_zifencei
# Check if the toolchain supports Zihintpause extension
riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE) := $(riscv-march-y)_zihintpause

-KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y))
+# Remove F,D,V from isa string for all. Keep extensions between "fd" and "v" by
+# matching non-v and non-multi-letter extensions out with the filter ([^v_]*)
+KBUILD_CFLAGS += -march=$(shell echo $(riscv-march-y) | sed -E 's/(rv32ima|rv64ima)fd([^v_]*)v?/\1\2/')
+
KBUILD_AFLAGS += -march=$(riscv-march-y)

KBUILD_CFLAGS += -mno-save-restore
--
2.17.1