diff mbox series

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

Message ID 20230414080701.15503-4-jiaxun.yang@flygoat.com (mailing list archive)
State Superseded
Headers show
Series MIPS: LLVM toolchain support for more CPUs | expand

Commit Message

Jiaxun Yang April 14, 2023, 8:06 a.m. UTC 
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(-)

Comments

Thomas Bogendoerfer April 18, 2023, 1:09 p.m. UTC | #1 
On Fri, Apr 14, 2023 at 09:06:57AM +0100, Jiaxun Yang wrote:
> LLVM toolchain does not support most of workarounds, detect
> those supports in Kconfig so we can hide unsupported workarounds
> to user.

again hiding something, which then needs to be digged out is IMHO not
a good way.

Thomas.
Jiaxun Yang April 18, 2023, 5:14 p.m. UTC | #2 
> 2023年4月18日 14:09，Thomas Bogendoerfer <tsbogend@alpha.franken.de> 写道：
> 
> On Fri, Apr 14, 2023 at 09:06:57AM +0100, Jiaxun Yang wrote:
>> LLVM toolchain does not support most of workarounds, detect
>> those supports in Kconfig so we can hide unsupported workarounds
>> to user.
> 
> again hiding something, which then needs to be digged out is IMHO not
> a good way.

Agreed, my universal target is to make every defconfig build against clang so we
can leverage clang’s warning to find any potential problems, and possibly use clang
built kernel on machines that don't need those workaround. Seems like better option
Is to let user to drop those configs manually.

Will drop this two patch.

Thanks
Jiaxun


> 
> Thomas.
> 
> -- 
> Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
> good idea.                                                [ RFC1925, 2.3 ]
diff mbox series

Patch

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