[PATCH v2 3/7] MIPS: Detect toolchain support of workarounds in Kconfig

[Jiaxun Yang <jiaxun.yang@flygoat.com>]

LLVM toolchain does not support most of workarounds, detect
those supports in Kconfig so we can hide unsupported workarounds
to user.

Link: https://github.com/ClangBuiltLinux/linux/issues/1544
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/mips/Kconfig               | 28 +++++++++++++++++++++++++---
 arch/mips/Makefile              |  6 +++---
 arch/mips/cavium-octeon/Kconfig |  1 +
 3 files changed, 29 insertions(+), 6 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 0b270562c3eb..0cd9cd01b7ab 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -371,9 +371,9 @@ config MACH_DECSTATION
 	select CEVT_R4K if CPU_R4X00
 	select CSRC_IOASIC
 	select CSRC_R4K if CPU_R4X00
-	select CPU_DADDI_WORKAROUNDS if 64BIT
-	select CPU_R4000_WORKAROUNDS if 64BIT
-	select CPU_R4400_WORKAROUNDS if 64BIT
+	imply CPU_DADDI_WORKAROUNDS
+	imply CPU_R4000_WORKAROUNDS
+	imply CPU_R4400_WORKAROUNDS
 	select DMA_NONCOHERENT
 	select NO_IOPORT_MAP
 	select IRQ_MIPS_CPU
@@ -1723,6 +1723,7 @@ config CPU_JUMP_WORKAROUNDS
 config CPU_LOONGSON2F_WORKAROUNDS
 	bool "Loongson 2F Workarounds"
 	default y
+	depends on AS_HAS_NOP_WORKAROUNDS && AS_HAS_JUMP_WORKAROUNDS
 	select CPU_NOP_WORKAROUNDS
 	select CPU_JUMP_WORKAROUNDS
 	help
@@ -2457,6 +2458,7 @@ config CPU_HAS_SYNC
 #   "MIPS R4400MC Errata, Processor Revision 1.0", erratum #5
 config CPU_DADDI_WORKAROUNDS
 	bool
+	depends on CPU_R4X00_BUGS64 && CC_HAS_DADDI_WORKAROUNDS
 
 # Work around certain R4000 CPU errata (as implemented by GCC):
 #
@@ -2478,6 +2480,7 @@ config CPU_DADDI_WORKAROUNDS
 #   erratum #52
 config CPU_R4000_WORKAROUNDS
 	bool
+	depends on CPU_R4X00_BUGS64 && CC_HAS_R4000_WORKAROUNDS
 	select CPU_R4400_WORKAROUNDS
 
 # Work around certain R4400 CPU errata (as implemented by GCC):
@@ -2488,6 +2491,7 @@ config CPU_R4000_WORKAROUNDS
 #   "MIPS R4400MC Errata, Processor Revision 2.0 & 3.0", erratum #4
 config CPU_R4400_WORKAROUNDS
 	bool
+	depends on CPU_R4X00_BUGS64 && CC_HAS_R4400_WORKAROUNDS
 
 config CPU_R4X00_BUGS64
 	bool
@@ -3168,6 +3172,15 @@ config CC_HAS_MNO_BRANCH_LIKELY
 	def_bool y
 	depends on $(cc-option,-mno-branch-likely)
 
+config CC_HAS_R4000_WORKAROUNDS
+	def_bool $(cc-option,-mfix-r4000)
+
+config CC_HAS_R4400_WORKAROUNDS
+	def_bool $(cc-option,-mfix-r4400)
+
+config CC_HAS_DADDI_WORKAROUNDS
+	def_bool $(cc-option,-mno-daddi)
+
 # https://github.com/llvm/llvm-project/issues/61045
 config CC_HAS_BROKEN_INLINE_COMPAT_BRANCH
 	def_bool y if CC_IS_CLANG
@@ -3193,6 +3206,15 @@ config AS_HAS_DSP
 config AS_HAS_GINV
 	def_bool $(cc-option,-Wa$(comma)-mginv)
 
+config AS_HAS_CN63XXP1_WORKAROUNDS
+	def_bool $(cc-option,-Wa$(comma)-mfix-cn63xxp1)
+
+config AS_HAS_NOP_WORKAROUNDS
+	def_bool $(cc-option,-Wa$(comma)-mfix-loongson2f-nop)
+
+config AS_HAS_JUMP_WORKAROUNDS
+	def_bool $(cc-option,-Wa$(comma)-mfix-loongson2f-jump)
+
 menu "Power management options"
 
 config ARCH_HIBERNATION_POSSIBLE
diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 3aa0f9d4ceb6..344fe5f00f7b 100644
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -193,9 +193,9 @@ cflags-$(CONFIG_CC_IS_CLANG) += -march=mips64r2
 endif
 cflags-$(CONFIG_CPU_LOONGSON64) += $(call cc-option,-mno-loongson-mmi)
 
-cflags-$(CONFIG_CPU_R4000_WORKAROUNDS)	+= $(call cc-option,-mfix-r4000,)
-cflags-$(CONFIG_CPU_R4400_WORKAROUNDS)	+= $(call cc-option,-mfix-r4400,)
-cflags-$(CONFIG_CPU_DADDI_WORKAROUNDS)	+= $(call cc-option,-mno-daddi,)
+cflags-$(CONFIG_CPU_R4000_WORKAROUNDS)	+= -mfix-r4000
+cflags-$(CONFIG_CPU_R4400_WORKAROUNDS)	+= -mfix-r4400
+cflags-$(CONFIG_CPU_DADDI_WORKAROUNDS)	+= -mno-daddi
 ifdef CONFIG_CPU_LOONGSON2F_WORKAROUNDS
 cflags-$(CONFIG_CPU_NOP_WORKAROUNDS) += -Wa,-mfix-loongson2f-nop
 cflags-$(CONFIG_CPU_JUMP_WORKAROUNDS) += -Wa,-mfix-loongson2f-jump
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 450e979ef5d9..38c9dc89cd5f 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -4,6 +4,7 @@ if CPU_CAVIUM_OCTEON
 config CAVIUM_CN63XXP1
 	bool "Enable CN63XXP1 errata workarounds"
 	default "n"
+	depends on AS_HAS_CN63XXP1_WORKAROUNDS
 	help
 	  The CN63XXP1 chip requires build time workarounds to
 	  function reliably, select this option to enable them.  These
-- 
2.39.2 (Apple Git-143)