[PATCH 2/2] x86, Makefile: Add new generic x86-64 settings v2/v3/v4

From: torvic9
Date: Tue Aug 17 2021 - 10:24:58 EST


Add new generic x86-64 CPU tunings introduced with recent versions of
gcc and clang, as documented in x86-64-psABI [1].

This is taken straight from graysky's CPU optimization patch with minor
modifications [2].

[1] https://gitlab.com/x86-psABIs/x86-64-ABI/-/commit/77566eb03bc6a326811cb7e9a6b9396884b67c7c
[2] https://github.com/graysky2/kernel_compiler_patch

Signed-off-by: Tor Vic <torvic9@xxxxxxxxxxx>
---
arch/x86/Kconfig.cpu | 26 +++++++++++++++++++++++++-
arch/x86/Makefile.cpu | 6 ++++++
2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 814fe0d349b0..a2c872aa5a0b 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -294,6 +294,30 @@ config GENERIC_CPU
Generic x86-64 CPU.
Run equally well on all x86-64 CPUs.

+config GENERIC_CPU_V2
+ bool "Generic-x86-64-v2"
+ depends on ( CC_IS_GCC && GCC_VERSION > 110000 ) || ( CC_IS_CLANG && CLANG_VERSION >= 120000 )
+ depends on X86_64
+ help
+ Generic x86-64 CPU.
+ Run equally well on all x86-64 CPUs with min support of x86-64-v2.
+
+config GENERIC_CPU_V3
+ bool "Generic-x86-64-v3"
+ depends on ( CC_IS_GCC && GCC_VERSION > 110000 ) || ( CC_IS_CLANG && CLANG_VERSION >= 120000 )
+ depends on X86_64
+ help
+ Generic x86-64-v3 CPU with v3 instructions.
+ Run equally well on all x86-64 CPUs with min support of x86-64-v3.
+
+config GENERIC_CPU_V4
+ bool "Generic-x86-64-v4"
+ depends on ( CC_IS_GCC && GCC_VERSION > 110000 ) || ( CC_IS_CLANG && CLANG_VERSION >= 120000 )
+ depends on X86_64
+ help
+ Generic x86-64 CPU with v4 instructions.
+ Run equally well on all x86-64 CPUs with min support of x86-64-v4.
+
endchoice

config X86_GENERIC
@@ -318,7 +342,7 @@ config X86_INTERNODE_CACHE_SHIFT
config X86_L1_CACHE_SHIFT
int
default "7" if MPENTIUM4 || MPSC
- default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MATOM || MVIAC7 || X86_GENERIC || GENERIC_CPU
+ default "6" if MK7 || MK8 || MPENTIUMM || MCORE2 || MATOM || MVIAC7 || X86_GENERIC || GENERIC_CPU || GENERIC_CPU_V2 || GENERIC_CPU_V3 || GENERIC_CPU_V4
default "4" if MELAN || M486SX || M486 || MGEODEGX1
default "5" if MWINCHIP3D || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX

diff --git a/arch/x86/Makefile.cpu b/arch/x86/Makefile.cpu
index fb407ae94d90..f190feefe964 100644
--- a/arch/x86/Makefile.cpu
+++ b/arch/x86/Makefile.cpu
@@ -10,3 +10,9 @@ cflags-$(CONFIG_MCORE2) += \
cflags-$(CONFIG_MATOM) += $(call cc-option,-march=atom) \
$(call cc-option,-mtune=atom,$(call cc-option,-mtune=generic))
cflags-$(CONFIG_GENERIC_CPU) += $(call cc-option,-mtune=generic)
+
+# New generic x86-64 CPU options.
+# Don't call the compiler, we have Kconfig compiler checks for these.
+cflags-$(CONFIG_GENERIC_CPU_V2) += -march=x86-64-v2
+cflags-$(CONFIG_GENERIC_CPU_V3) += -march=x86-64-v3
+cflags-$(CONFIG_GENERIC_CPU_V4) += -march=x86-64-v4
--
2.32.0