[PATCH -next v21 24/27] riscv: Enable Vector code to be built

Andy Chiu
2023-06-05T15:42:16Z

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

This patch adds configs for building Vector code. First it detects the
reqired toolchain support for building the code. Then it provides an
option setting whether Vector is implicitly enabled to userspace.

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>
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>
---
Changelog v20:
- s/RISCV_V_DISABLE/RISCV_ISA_V_DEFAULT_ENABLE/ for better
understanding (Conor)
- Update commit message (Conor)
Changelog V19:
- Add RISCV_V_DISABLE to set compile-time default.
---
arch/riscv/Kconfig | 31 +++++++++++++++++++++++++++++++
arch/riscv/Makefile | 6 +++++-
2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 1019b519d590..f3ba0a8b085e 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -466,6 +466,37 @@ 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 || $(cc-option,-mabi=ilp32 -march=rv32iv)
+ depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800
+ depends on AS_HAS_OPTION_ARCH
+
+config RISCV_ISA_V
+ bool "VECTOR extension support"
+ depends on TOOLCHAIN_HAS_V
+ depends on FPU
+ select DYNAMIC_SIGFRAME
+ default y
+ help
+ Say N here if you want to disable all vector related procedure
+ in the kernel.
+
+ If you don't know what to do here, say Y.
+
+config RISCV_ISA_V_DEFAULT_ENABLE
+ bool "Enable userspace Vector by default"
+ depends on RISCV_ISA_V
+ default y
+ help
+ Say Y here if you want to enable Vector in userspace by default.
+ Otherwise, userspace has to make explicit prctl() call to enable
+ Vector, or enable it via the sysctl interface.
+
+ If you don't know what to do here, say Y.
+
config TOOLCHAIN_HAS_ZBB
bool
default y
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index 0fb256bf8270..6ec6d52a4180 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -60,6 +60,7 @@ riscv-march-$(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

ifdef CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC
KBUILD_CFLAGS += -Wa,-misa-spec=2.2
@@ -71,7 +72,10 @@ endif
# 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