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* [PATCH v4 0/4] pass -march= only to compiler
@ 2022-10-14 20:13 ` Nick Desaulniers
  0 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

When both -march= and -Wa,-march= are specified for assembler or
assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
value but Clang will warn that -march= is unused.

warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

This is the top group of warnings we observe when using clang to
assemble the kernel via `ARCH=arm make LLVM=1`.

Arnd sent a v2 of my previous patch
https://lore.kernel.org/linux-arm-kernel/20210928154143.2106903-14-arnd@kernel.org/
I added yet a few more instances I found since then. Nathan pointed out
a new one too that I've fixed since v3.

Fixing this will allow us to enable
-Werror=unused-command-line-argument for clang builds.

v3 had an issue wrt. __thumb2__
https://lore.kernel.org/llvm/CAKwvOdmkd2PxvMUZA=A-72eATGDZkqDj--Bv1W+Xt_K_LWdROA@mail.gmail.com/
I've incorporated idea from Nathan and Ard on that.

Nick Desaulniers (4):
  ARM: remove lazy evaluation in Makefile
  ARM: use .arch directives instead of assembler command line flags
  ARM: only use -mtp=cp15 for the compiler
  ARM: pass -march= only to compiler

 arch/arm/Makefile                   | 78 ++++++++++++++++-------------
 arch/arm/boot/compressed/Makefile   |  1 -
 arch/arm/common/Makefile            |  2 -
 arch/arm/common/mcpm_head.S         |  2 +
 arch/arm/common/vlock.S             |  2 +
 arch/arm/kernel/Makefile            |  2 -
 arch/arm/kernel/hyp-stub.S          |  2 +
 arch/arm/kernel/swp_emulate.c       |  1 +
 arch/arm/lib/Makefile               |  4 --
 arch/arm/lib/delay-loop.S           |  4 ++
 arch/arm/mach-at91/Makefile         |  3 --
 arch/arm/mach-at91/pm_suspend.S     |  4 ++
 arch/arm/mach-imx/Makefile          |  3 --
 arch/arm/mach-imx/headsmp.S         |  2 +
 arch/arm/mach-imx/resume-imx6.S     |  2 +
 arch/arm/mach-imx/suspend-imx6.S    |  2 +
 arch/arm/mach-mvebu/Makefile        |  3 --
 arch/arm/mach-mvebu/coherency_ll.S  |  1 +
 arch/arm/mach-mvebu/pmsu.c          |  1 +
 arch/arm/mach-npcm/Makefile         |  2 -
 arch/arm/mach-npcm/headsmp.S        |  2 +
 arch/arm/mach-tegra/Makefile        |  2 -
 arch/arm/mach-tegra/reset-handler.S |  2 +
 arch/arm/mach-tegra/sleep-tegra20.S |  2 +
 arch/arm/mach-tegra/sleep-tegra30.S |  2 +
 arch/arm/mach-tegra/sleep.S         |  2 +
 arch/arm/mm/Makefile                | 15 ------
 arch/arm/mm/abort-ev6.S             |  1 +
 arch/arm/mm/abort-ev7.S             |  1 +
 arch/arm/mm/cache-v6.S              |  2 +
 arch/arm/mm/cache-v7.S              |  2 +
 arch/arm/mm/cache-v7m.S             |  2 +
 arch/arm/mm/copypage-feroceon.c     |  1 +
 arch/arm/mm/proc-v6.S               |  2 +
 arch/arm/mm/proc-v7-2level.S        |  2 +
 arch/arm/mm/proc-v7.S               |  2 +
 arch/arm/mm/tlb-v6.S                |  2 +
 arch/arm/mm/tlb-v7.S                |  2 +
 drivers/memory/Makefile             |  2 -
 drivers/memory/ti-emif-sram-pm.S    |  1 +
 drivers/soc/bcm/brcmstb/pm/Makefile |  1 -
 drivers/soc/bcm/brcmstb/pm/s2-arm.S |  1 +
 42 files changed, 97 insertions(+), 75 deletions(-)

-- 
2.38.0.413.g74048e4d9e-goog


^ permalink raw reply	[flat|nested] 26+ messages in thread
* [PATCH v4 0/4] pass -march= only to compiler
@ 2022-10-14 20:13 ` Nick Desaulniers
  0 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

When both -march= and -Wa,-march= are specified for assembler or
assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
value but Clang will warn that -march= is unused.

warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

This is the top group of warnings we observe when using clang to
assemble the kernel via `ARCH=arm make LLVM=1`.

Arnd sent a v2 of my previous patch
https://lore.kernel.org/linux-arm-kernel/20210928154143.2106903-14-arnd@kernel.org/
I added yet a few more instances I found since then. Nathan pointed out
a new one too that I've fixed since v3.

Fixing this will allow us to enable
-Werror=unused-command-line-argument for clang builds.

v3 had an issue wrt. __thumb2__
https://lore.kernel.org/llvm/CAKwvOdmkd2PxvMUZA=A-72eATGDZkqDj--Bv1W+Xt_K_LWdROA@mail.gmail.com/
I've incorporated idea from Nathan and Ard on that.

Nick Desaulniers (4):
  ARM: remove lazy evaluation in Makefile
  ARM: use .arch directives instead of assembler command line flags
  ARM: only use -mtp=cp15 for the compiler
  ARM: pass -march= only to compiler

 arch/arm/Makefile                   | 78 ++++++++++++++++-------------
 arch/arm/boot/compressed/Makefile   |  1 -
 arch/arm/common/Makefile            |  2 -
 arch/arm/common/mcpm_head.S         |  2 +
 arch/arm/common/vlock.S             |  2 +
 arch/arm/kernel/Makefile            |  2 -
 arch/arm/kernel/hyp-stub.S          |  2 +
 arch/arm/kernel/swp_emulate.c       |  1 +
 arch/arm/lib/Makefile               |  4 --
 arch/arm/lib/delay-loop.S           |  4 ++
 arch/arm/mach-at91/Makefile         |  3 --
 arch/arm/mach-at91/pm_suspend.S     |  4 ++
 arch/arm/mach-imx/Makefile          |  3 --
 arch/arm/mach-imx/headsmp.S         |  2 +
 arch/arm/mach-imx/resume-imx6.S     |  2 +
 arch/arm/mach-imx/suspend-imx6.S    |  2 +
 arch/arm/mach-mvebu/Makefile        |  3 --
 arch/arm/mach-mvebu/coherency_ll.S  |  1 +
 arch/arm/mach-mvebu/pmsu.c          |  1 +
 arch/arm/mach-npcm/Makefile         |  2 -
 arch/arm/mach-npcm/headsmp.S        |  2 +
 arch/arm/mach-tegra/Makefile        |  2 -
 arch/arm/mach-tegra/reset-handler.S |  2 +
 arch/arm/mach-tegra/sleep-tegra20.S |  2 +
 arch/arm/mach-tegra/sleep-tegra30.S |  2 +
 arch/arm/mach-tegra/sleep.S         |  2 +
 arch/arm/mm/Makefile                | 15 ------
 arch/arm/mm/abort-ev6.S             |  1 +
 arch/arm/mm/abort-ev7.S             |  1 +
 arch/arm/mm/cache-v6.S              |  2 +
 arch/arm/mm/cache-v7.S              |  2 +
 arch/arm/mm/cache-v7m.S             |  2 +
 arch/arm/mm/copypage-feroceon.c     |  1 +
 arch/arm/mm/proc-v6.S               |  2 +
 arch/arm/mm/proc-v7-2level.S        |  2 +
 arch/arm/mm/proc-v7.S               |  2 +
 arch/arm/mm/tlb-v6.S                |  2 +
 arch/arm/mm/tlb-v7.S                |  2 +
 drivers/memory/Makefile             |  2 -
 drivers/memory/ti-emif-sram-pm.S    |  1 +
 drivers/soc/bcm/brcmstb/pm/Makefile |  1 -
 drivers/soc/bcm/brcmstb/pm/s2-arm.S |  1 +
 42 files changed, 97 insertions(+), 75 deletions(-)

-- 
2.38.0.413.g74048e4d9e-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* [PATCH v4 1/4] ARM: remove lazy evaluation in Makefile
  2022-10-14 20:13 ` Nick Desaulniers
@ 2022-10-14 20:13   ` Nick Desaulniers
  -1 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

arch-y and tune-y used lazy evaluation since they used to contain
cc-option checks. They don't any longer, so just eagerly evaluate these
command line flags.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
No change from v3.

 arch/arm/Makefile | 60 +++++++++++++++++++++--------------------------
 1 file changed, 27 insertions(+), 33 deletions(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index c846119c448f..8dd943b50b7d 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -63,44 +63,38 @@ KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
 # Note that GCC does not numerically define an architecture version
 # macro, but instead defines a whole series of macros which makes
 # testing for a specific architecture or later rather impossible.
-arch-$(CONFIG_CPU_32v7M)	=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
-arch-$(CONFIG_CPU_32v7)		=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
-arch-$(CONFIG_CPU_32v6)		=-D__LINUX_ARM_ARCH__=6 -march=armv6
-# Only override the compiler option if ARMv6. The ARMv6K extensions are
+arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
+arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
+arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
+# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
 # always available in ARMv7
 ifeq ($(CONFIG_CPU_32v6),y)
-arch-$(CONFIG_CPU_32v6K)	=-D__LINUX_ARM_ARCH__=6 -march=armv6k
+arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
 endif
-arch-$(CONFIG_CPU_32v5)		=-D__LINUX_ARM_ARCH__=5 -march=armv5te
-arch-$(CONFIG_CPU_32v4T)	=-D__LINUX_ARM_ARCH__=4 -march=armv4t
-arch-$(CONFIG_CPU_32v4)		=-D__LINUX_ARM_ARCH__=4 -march=armv4
-arch-$(CONFIG_CPU_32v3)		=-D__LINUX_ARM_ARCH__=3 -march=armv3m
-
-# Evaluate arch cc-option calls now
-arch-y := $(arch-y)
+arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
+arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
+arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
+arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
 
 # This selects how we optimise for the processor.
-tune-$(CONFIG_CPU_ARM7TDMI)	=-mtune=arm7tdmi
-tune-$(CONFIG_CPU_ARM720T)	=-mtune=arm7tdmi
-tune-$(CONFIG_CPU_ARM740T)	=-mtune=arm7tdmi
-tune-$(CONFIG_CPU_ARM9TDMI)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM940T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM946E)	=-mtune=arm9e
-tune-$(CONFIG_CPU_ARM920T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM922T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM925T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM926T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_FA526)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_SA110)	=-mtune=strongarm110
-tune-$(CONFIG_CPU_SA1100)	=-mtune=strongarm1100
-tune-$(CONFIG_CPU_XSCALE)	=-mtune=xscale
-tune-$(CONFIG_CPU_XSC3)		=-mtune=xscale
-tune-$(CONFIG_CPU_FEROCEON)	=-mtune=xscale
-tune-$(CONFIG_CPU_V6)		=-mtune=arm1136j-s
-tune-$(CONFIG_CPU_V6K)		=-mtune=arm1136j-s
-
-# Evaluate tune cc-option calls now
-tune-y := $(tune-y)
+tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
+tune-$(CONFIG_CPU_ARM720T)	:=-mtune=arm7tdmi
+tune-$(CONFIG_CPU_ARM740T)	:=-mtune=arm7tdmi
+tune-$(CONFIG_CPU_ARM9TDMI)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM940T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM946E)	:=-mtune=arm9e
+tune-$(CONFIG_CPU_ARM920T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM922T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM925T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM926T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_FA526)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_SA110)	:=-mtune=strongarm110
+tune-$(CONFIG_CPU_SA1100)	:=-mtune=strongarm1100
+tune-$(CONFIG_CPU_XSCALE)	:=-mtune=xscale
+tune-$(CONFIG_CPU_XSC3)		:=-mtune=xscale
+tune-$(CONFIG_CPU_FEROCEON)	:=-mtune=xscale
+tune-$(CONFIG_CPU_V6)		:=-mtune=arm1136j-s
+tune-$(CONFIG_CPU_V6K)		:=-mtune=arm1136j-s
 
 ifeq ($(CONFIG_AEABI),y)
 CFLAGS_ABI	:=-mabi=aapcs-linux -mfpu=vfp
-- 
2.38.0.413.g74048e4d9e-goog


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v4 1/4] ARM: remove lazy evaluation in Makefile
@ 2022-10-14 20:13   ` Nick Desaulniers
  0 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

arch-y and tune-y used lazy evaluation since they used to contain
cc-option checks. They don't any longer, so just eagerly evaluate these
command line flags.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
No change from v3.

 arch/arm/Makefile | 60 +++++++++++++++++++++--------------------------
 1 file changed, 27 insertions(+), 33 deletions(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index c846119c448f..8dd943b50b7d 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -63,44 +63,38 @@ KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
 # Note that GCC does not numerically define an architecture version
 # macro, but instead defines a whole series of macros which makes
 # testing for a specific architecture or later rather impossible.
-arch-$(CONFIG_CPU_32v7M)	=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
-arch-$(CONFIG_CPU_32v7)		=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
-arch-$(CONFIG_CPU_32v6)		=-D__LINUX_ARM_ARCH__=6 -march=armv6
-# Only override the compiler option if ARMv6. The ARMv6K extensions are
+arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
+arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
+arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
+# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
 # always available in ARMv7
 ifeq ($(CONFIG_CPU_32v6),y)
-arch-$(CONFIG_CPU_32v6K)	=-D__LINUX_ARM_ARCH__=6 -march=armv6k
+arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
 endif
-arch-$(CONFIG_CPU_32v5)		=-D__LINUX_ARM_ARCH__=5 -march=armv5te
-arch-$(CONFIG_CPU_32v4T)	=-D__LINUX_ARM_ARCH__=4 -march=armv4t
-arch-$(CONFIG_CPU_32v4)		=-D__LINUX_ARM_ARCH__=4 -march=armv4
-arch-$(CONFIG_CPU_32v3)		=-D__LINUX_ARM_ARCH__=3 -march=armv3m
-
-# Evaluate arch cc-option calls now
-arch-y := $(arch-y)
+arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
+arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
+arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
+arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
 
 # This selects how we optimise for the processor.
-tune-$(CONFIG_CPU_ARM7TDMI)	=-mtune=arm7tdmi
-tune-$(CONFIG_CPU_ARM720T)	=-mtune=arm7tdmi
-tune-$(CONFIG_CPU_ARM740T)	=-mtune=arm7tdmi
-tune-$(CONFIG_CPU_ARM9TDMI)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM940T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM946E)	=-mtune=arm9e
-tune-$(CONFIG_CPU_ARM920T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM922T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM925T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_ARM926T)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_FA526)	=-mtune=arm9tdmi
-tune-$(CONFIG_CPU_SA110)	=-mtune=strongarm110
-tune-$(CONFIG_CPU_SA1100)	=-mtune=strongarm1100
-tune-$(CONFIG_CPU_XSCALE)	=-mtune=xscale
-tune-$(CONFIG_CPU_XSC3)		=-mtune=xscale
-tune-$(CONFIG_CPU_FEROCEON)	=-mtune=xscale
-tune-$(CONFIG_CPU_V6)		=-mtune=arm1136j-s
-tune-$(CONFIG_CPU_V6K)		=-mtune=arm1136j-s
-
-# Evaluate tune cc-option calls now
-tune-y := $(tune-y)
+tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
+tune-$(CONFIG_CPU_ARM720T)	:=-mtune=arm7tdmi
+tune-$(CONFIG_CPU_ARM740T)	:=-mtune=arm7tdmi
+tune-$(CONFIG_CPU_ARM9TDMI)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM940T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM946E)	:=-mtune=arm9e
+tune-$(CONFIG_CPU_ARM920T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM922T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM925T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_ARM926T)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_FA526)	:=-mtune=arm9tdmi
+tune-$(CONFIG_CPU_SA110)	:=-mtune=strongarm110
+tune-$(CONFIG_CPU_SA1100)	:=-mtune=strongarm1100
+tune-$(CONFIG_CPU_XSCALE)	:=-mtune=xscale
+tune-$(CONFIG_CPU_XSC3)		:=-mtune=xscale
+tune-$(CONFIG_CPU_FEROCEON)	:=-mtune=xscale
+tune-$(CONFIG_CPU_V6)		:=-mtune=arm1136j-s
+tune-$(CONFIG_CPU_V6K)		:=-mtune=arm1136j-s
 
 ifeq ($(CONFIG_AEABI),y)
 CFLAGS_ABI	:=-mabi=aapcs-linux -mfpu=vfp
-- 
2.38.0.413.g74048e4d9e-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
  2022-10-14 20:13 ` Nick Desaulniers
@ 2022-10-14 20:13   ` Nick Desaulniers
  -1 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

Similar to commit a6c30873ee4a ("ARM: 8989/1: use .fpu assembler
directives instead of assembler arguments").

GCC and GNU binutils support setting the "sub arch" via -march=,
-Wa,-march, target function attribute, and .arch assembler directive.

Clang was missing support for -Wa,-march=, but this was implemented in
clang-13.

The behavior of both GCC and Clang is to
prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
sources, but Clang will warn about the -march= being unused.

clang: warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

Since most assembler is non-conditionally assembled with one sub arch
(modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
.arch assembler directive.

Add a few more instances found in compile testing as found by Arnd and
Nathan.

Link: https://github.com/llvm/llvm-project/commit/1d51c699b9e2ebc5bcfdbe85c74cc871426333d4
Link: https://bugs.llvm.org/show_bug.cgi?id=48894
Link: https://github.com/ClangBuiltLinux/linux/issues/1195
Link: https://github.com/ClangBuiltLinux/linux/issues/1315
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
Changes v3 -> v4:
* Add .arch armv7-a to arch/arm/mach-tegra/sleep.S as per Nathan.
  https://github.com/ClangBuiltLinux/linux/issues/1315#issuecomment-1255646893
* Add Nathan's SB tag.

 arch/arm/boot/compressed/Makefile   |  1 -
 arch/arm/common/Makefile            |  2 --
 arch/arm/common/mcpm_head.S         |  2 ++
 arch/arm/common/vlock.S             |  2 ++
 arch/arm/kernel/Makefile            |  2 --
 arch/arm/kernel/hyp-stub.S          |  2 ++
 arch/arm/kernel/swp_emulate.c       |  1 +
 arch/arm/lib/Makefile               |  4 ----
 arch/arm/lib/delay-loop.S           |  4 ++++
 arch/arm/mach-at91/Makefile         |  3 ---
 arch/arm/mach-at91/pm_suspend.S     |  4 ++++
 arch/arm/mach-imx/Makefile          |  3 ---
 arch/arm/mach-imx/headsmp.S         |  2 ++
 arch/arm/mach-imx/resume-imx6.S     |  2 ++
 arch/arm/mach-imx/suspend-imx6.S    |  2 ++
 arch/arm/mach-mvebu/Makefile        |  3 ---
 arch/arm/mach-mvebu/coherency_ll.S  |  1 +
 arch/arm/mach-mvebu/pmsu.c          |  1 +
 arch/arm/mach-npcm/Makefile         |  2 --
 arch/arm/mach-npcm/headsmp.S        |  2 ++
 arch/arm/mach-tegra/Makefile        |  2 --
 arch/arm/mach-tegra/reset-handler.S |  2 ++
 arch/arm/mach-tegra/sleep-tegra20.S |  2 ++
 arch/arm/mach-tegra/sleep-tegra30.S |  2 ++
 arch/arm/mach-tegra/sleep.S         |  2 ++
 arch/arm/mm/Makefile                | 15 ---------------
 arch/arm/mm/abort-ev6.S             |  1 +
 arch/arm/mm/abort-ev7.S             |  1 +
 arch/arm/mm/cache-v6.S              |  2 ++
 arch/arm/mm/cache-v7.S              |  2 ++
 arch/arm/mm/cache-v7m.S             |  2 ++
 arch/arm/mm/copypage-feroceon.c     |  1 +
 arch/arm/mm/proc-v6.S               |  2 ++
 arch/arm/mm/proc-v7-2level.S        |  2 ++
 arch/arm/mm/proc-v7.S               |  2 ++
 arch/arm/mm/tlb-v6.S                |  2 ++
 arch/arm/mm/tlb-v7.S                |  2 ++
 drivers/memory/Makefile             |  2 --
 drivers/memory/ti-emif-sram-pm.S    |  1 +
 drivers/soc/bcm/brcmstb/pm/Makefile |  1 -
 drivers/soc/bcm/brcmstb/pm/s2-arm.S |  1 +
 41 files changed, 54 insertions(+), 40 deletions(-)

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 41bcbb460fac..e5c80ff42a4f 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -163,4 +163,3 @@ $(obj)/piggy_data: $(obj)/../Image FORCE
 $(obj)/piggy.o: $(obj)/piggy_data
 
 CFLAGS_font.o := -Dstatic=
-AFLAGS_hyp-stub.o := -Wa,-march=armv7-a
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 7bae8cbaafe7..9733381074e0 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -13,7 +13,5 @@ obj-$(CONFIG_SHARP_SCOOP)	+= scoop.o
 obj-$(CONFIG_CPU_V7)		+= secure_cntvoff.o
 obj-$(CONFIG_MCPM)		+= mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
 CFLAGS_REMOVE_mcpm_entry.o	= -pg
-AFLAGS_mcpm_head.o		:= -march=armv7-a
-AFLAGS_vlock.o			:= -march=armv7-a
 obj-$(CONFIG_BL_SWITCHER)	+= bL_switcher.o
 obj-$(CONFIG_BL_SWITCHER_DUMMY_IF) += bL_switcher_dummy_if.o
diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S
index 291d969bc719..299495c43dfd 100644
--- a/arch/arm/common/mcpm_head.S
+++ b/arch/arm/common/mcpm_head.S
@@ -15,6 +15,8 @@
 
 #include "vlock.h"
 
+.arch armv7-a
+
 .if MCPM_SYNC_CLUSTER_CPUS
 .error "cpus must be the first member of struct mcpm_sync_struct"
 .endif
diff --git a/arch/arm/common/vlock.S b/arch/arm/common/vlock.S
index f1c7fd44f1b1..1fa09c4697ed 100644
--- a/arch/arm/common/vlock.S
+++ b/arch/arm/common/vlock.S
@@ -12,6 +12,8 @@
 #include <linux/linkage.h>
 #include "vlock.h"
 
+.arch armv7-a
+
 /* Select different code if voting flags  can fit in a single word. */
 #if VLOCK_VOTING_SIZE > 4
 #define FEW(x...)
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 48737ec800eb..d53f56d6f840 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -70,7 +70,6 @@ obj-$(CONFIG_HAVE_TCM)		+= tcm.o
 obj-$(CONFIG_OF)		+= devtree.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_SWP_EMULATE)	+= swp_emulate.o
-CFLAGS_swp_emulate.o		:= -Wa,-march=armv7-a
 obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
 
 obj-$(CONFIG_CPU_XSCALE)	+= xscale-cp0.o
@@ -99,7 +98,6 @@ CFLAGS_head-inflate-data.o := $(call cc-option,-Wframe-larger-than=10240)
 obj-$(CONFIG_XIP_DEFLATED_DATA) += head-inflate-data.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o
-AFLAGS_hyp-stub.o		:=-Wa,-march=armv7-a
 ifeq ($(CONFIG_ARM_PSCI),y)
 obj-$(CONFIG_SMP)		+= psci_smp.o
 endif
diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
index b699b22a4db1..3a506b9095a5 100644
--- a/arch/arm/kernel/hyp-stub.S
+++ b/arch/arm/kernel/hyp-stub.S
@@ -9,6 +9,8 @@
 #include <asm/assembler.h>
 #include <asm/virt.h>
 
+.arch armv7-a
+
 #ifndef ZIMAGE
 /*
  * For the kernel proper, we need to find out the CPU boot mode long after
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index b74bfcf94fb1..fdce83c95acb 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -34,6 +34,7 @@
  */
 #define __user_swpX_asm(data, addr, res, temp, B)		\
 	__asm__ __volatile__(					\
+	".arch armv7-a\n"					\
 	"0:	ldrex"B"	%2, [%3]\n"			\
 	"1:	strex"B"	%0, %1, [%3]\n"			\
 	"	cmp		%0, #0\n"			\
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 6d2ba454f25b..42fb75c06647 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -36,10 +36,6 @@ else
   lib-y	+= io-readsw-armv4.o io-writesw-armv4.o
 endif
 
-ifeq ($(CONFIG_ARCH_RPC),y)
-  AFLAGS_delay-loop.o		+= -march=armv4
-endif
-
 $(obj)/csumpartialcopy.o:	$(obj)/csumpartialcopygeneric.S
 $(obj)/csumpartialcopyuser.o:	$(obj)/csumpartialcopygeneric.S
 
diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S
index 3ccade0f8130..3ac05177d097 100644
--- a/arch/arm/lib/delay-loop.S
+++ b/arch/arm/lib/delay-loop.S
@@ -8,6 +8,10 @@
 #include <asm/assembler.h>
 #include <asm/delay.h>
 
+#ifdef CONFIG_ARCH_RPC
+		.arch	armv4
+#endif
+
 		.text
 
 .LC0:		.word	loops_per_jiffy
diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
index 0dcc37180588..794bd12ab0a8 100644
--- a/arch/arm/mach-at91/Makefile
+++ b/arch/arm/mach-at91/Makefile
@@ -14,9 +14,6 @@ obj-$(CONFIG_SOC_SAMV7)		+= samv7.o
 # Power Management
 obj-$(CONFIG_ATMEL_PM)		+= pm.o pm_suspend.o
 
-ifeq ($(CONFIG_CPU_V7),y)
-AFLAGS_pm_suspend.o := -march=armv7-a
-endif
 ifeq ($(CONFIG_PM_DEBUG),y)
 CFLAGS_pm.o += -DDEBUG
 endif
diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index ffed4d949042..78d65809155f 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -12,6 +12,10 @@
 #include "pm.h"
 #include "pm_data-offsets.h"
 
+#ifdef CONFIG_CPU_V7
+.arch armv7-a
+#endif
+
 #define	SRAMC_SELF_FRESH_ACTIVE		0x01
 #define	SRAMC_SELF_FRESH_EXIT		0x00
 
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 6fb3965b9ae6..5c650bf40e02 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -34,7 +34,6 @@ obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
 obj-$(CONFIG_HAVE_IMX_MMDC) += mmdc.o
 obj-$(CONFIG_HAVE_IMX_SRC) += src.o
 ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_IMX7D_CA7)$(CONFIG_SOC_LS1021A),)
-AFLAGS_headsmp.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SMP) += headsmp.o platsmp.o
 obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
 endif
@@ -48,12 +47,10 @@ obj-$(CONFIG_SOC_IMX7D_CM4) += mach-imx7d-cm4.o
 obj-$(CONFIG_SOC_IMX7ULP) += mach-imx7ulp.o pm-imx7ulp.o
 
 ifeq ($(CONFIG_SUSPEND),y)
-AFLAGS_suspend-imx6.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SOC_IMX6) += suspend-imx6.o
 obj-$(CONFIG_SOC_IMX53) += suspend-imx53.o
 endif
 ifeq ($(CONFIG_ARM_CPU_SUSPEND),y)
-AFLAGS_resume-imx6.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SOC_IMX6) += resume-imx6.o
 endif
 obj-$(CONFIG_SOC_IMX6) += pm-imx6.o
diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
index fcba58be8e79..5f9c7b48ae80 100644
--- a/arch/arm/mach-imx/headsmp.S
+++ b/arch/arm/mach-imx/headsmp.S
@@ -8,6 +8,8 @@
 #include <linux/init.h>
 #include <asm/assembler.h>
 
+.arch armv7-a
+
 diag_reg_offset:
 	.word	g_diag_reg - .
 
diff --git a/arch/arm/mach-imx/resume-imx6.S b/arch/arm/mach-imx/resume-imx6.S
index 5bd1ba7ef15b..2c0c5c771251 100644
--- a/arch/arm/mach-imx/resume-imx6.S
+++ b/arch/arm/mach-imx/resume-imx6.S
@@ -9,6 +9,8 @@
 #include <asm/hardware/cache-l2x0.h>
 #include "hardware.h"
 
+.arch armv7-a
+
 /*
  * The following code must assume it is running from physical address
  * where absolute virtual addresses to the data section have to be
diff --git a/arch/arm/mach-imx/suspend-imx6.S b/arch/arm/mach-imx/suspend-imx6.S
index e06f946b75b9..63ccc2d0e920 100644
--- a/arch/arm/mach-imx/suspend-imx6.S
+++ b/arch/arm/mach-imx/suspend-imx6.S
@@ -9,6 +9,8 @@
 #include <asm/hardware/cache-l2x0.h>
 #include "hardware.h"
 
+.arch armv7-a
+
 /*
  * ==================== low level suspend ====================
  *
diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index c21733cbb4fa..569768a69ffc 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile
@@ -1,9 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 ccflags-y := -I$(srctree)/arch/arm/plat-orion/include
 
-AFLAGS_coherency_ll.o		:= -Wa,-march=armv7-a
-CFLAGS_pmsu.o			:= -march=armv7-a
-
 obj-$(CONFIG_MACH_MVEBU_ANY)	 += system-controller.o mvebu-soc-id.o
 
 ifeq ($(CONFIG_MACH_MVEBU_V7),y)
diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S
index eb81656e32d4..35930e03d9c6 100644
--- a/arch/arm/mach-mvebu/coherency_ll.S
+++ b/arch/arm/mach-mvebu/coherency_ll.S
@@ -20,6 +20,7 @@
 #include <asm/assembler.h>
 #include <asm/cp15.h>
 
+	.arch armv7-a
 	.text
 /*
  * Returns the coherency base address in r1 (r0 is untouched), or 0 if
diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
index af27a7156675..6f366d8c4231 100644
--- a/arch/arm/mach-mvebu/pmsu.c
+++ b/arch/arm/mach-mvebu/pmsu.c
@@ -291,6 +291,7 @@ int armada_370_xp_pmsu_idle_enter(unsigned long deepidle)
 
 	/* Test the CR_C bit and set it if it was cleared */
 	asm volatile(
+	".arch	armv7-a\n\t"
 	"mrc	p15, 0, r0, c1, c0, 0 \n\t"
 	"tst	r0, %0 \n\t"
 	"orreq	r0, r0, #(1 << 2) \n\t"
diff --git a/arch/arm/mach-npcm/Makefile b/arch/arm/mach-npcm/Makefile
index 8d61fcd42fb1..ac83e1caf2ee 100644
--- a/arch/arm/mach-npcm/Makefile
+++ b/arch/arm/mach-npcm/Makefile
@@ -1,6 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
-AFLAGS_headsmp.o		+= -march=armv7-a
-
 obj-$(CONFIG_ARCH_WPCM450)	+= wpcm450.o
 obj-$(CONFIG_ARCH_NPCM7XX)	+= npcm7xx.o
 obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o
diff --git a/arch/arm/mach-npcm/headsmp.S b/arch/arm/mach-npcm/headsmp.S
index c083fe09a07b..84d2b6daaf0b 100644
--- a/arch/arm/mach-npcm/headsmp.S
+++ b/arch/arm/mach-npcm/headsmp.S
@@ -6,6 +6,8 @@
 #include <linux/init.h>
 #include <asm/assembler.h>
 
+.arch armv7-a
+
 /*
  * The boot ROM does not start secondary CPUs in SVC mode, so we need to do that
  * here.
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 07572b5373b8..a2bb55bc0081 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -1,6 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-asflags-y				+= -march=armv7-a
-
 obj-y                                   += io.o
 obj-y                                   += irq.o
 obj-y					+= pm.o
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index 06ca44b09381..0ea456264f3e 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -19,6 +19,8 @@
 
 #define PMC_SCRATCH41	0x140
 
+.arch armv7-a
+
 #ifdef CONFIG_PM_SLEEP
 /*
  *	tegra_resume
diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
index a5a36cce142a..d8cd487a8f63 100644
--- a/arch/arm/mach-tegra/sleep-tegra20.S
+++ b/arch/arm/mach-tegra/sleep-tegra20.S
@@ -47,6 +47,8 @@
 #define PLLM_STORE_MASK			(1 << 1)
 #define PLLP_STORE_MASK			(1 << 2)
 
+.arch armv7-a
+
 .macro test_pll_state, rd, test_mask
 	ldr	\rd, tegra_pll_state
 	tst	\rd, #\test_mask
diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index 0cc40b6b2ba3..134ea5fe49b2 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -78,6 +78,8 @@
 #define PLLX_STORE_MASK			(1 << 4)
 #define PLLM_PMC_STORE_MASK		(1 << 5)
 
+.arch armv7-a
+
 .macro emc_device_mask, rd, base
 	ldr	\rd, [\base, #EMC_ADR_CFG]
 	tst	\rd, #0x1
diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S
index 8f88944831c5..945f2c1474f7 100644
--- a/arch/arm/mach-tegra/sleep.S
+++ b/arch/arm/mach-tegra/sleep.S
@@ -22,6 +22,8 @@
 #define CLK_RESET_CCLK_BURST	0x20
 #define CLK_RESET_CCLK_DIVIDER  0x24
 
+.arch armv7-a
+
 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
 /*
  * tegra_disable_clean_inv_dcache
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 3510503bc5e6..71b858c9b10c 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -33,9 +33,6 @@ obj-$(CONFIG_CPU_ABRT_EV5TJ)	+= abort-ev5tj.o
 obj-$(CONFIG_CPU_ABRT_EV6)	+= abort-ev6.o
 obj-$(CONFIG_CPU_ABRT_EV7)	+= abort-ev7.o
 
-AFLAGS_abort-ev6.o	:=-Wa,-march=armv6k
-AFLAGS_abort-ev7.o	:=-Wa,-march=armv7-a
-
 obj-$(CONFIG_CPU_PABRT_LEGACY)	+= pabort-legacy.o
 obj-$(CONFIG_CPU_PABRT_V6)	+= pabort-v6.o
 obj-$(CONFIG_CPU_PABRT_V7)	+= pabort-v7.o
@@ -49,10 +46,6 @@ obj-$(CONFIG_CPU_CACHE_FA)	+= cache-fa.o
 obj-$(CONFIG_CPU_CACHE_NOP)	+= cache-nop.o
 obj-$(CONFIG_CPU_CACHE_V7M)	+= cache-v7m.o
 
-AFLAGS_cache-v6.o	:=-Wa,-march=armv6
-AFLAGS_cache-v7.o	:=-Wa,-march=armv7-a
-AFLAGS_cache-v7m.o	:=-Wa,-march=armv7-m
-
 obj-$(CONFIG_CPU_COPY_V4WT)	+= copypage-v4wt.o
 obj-$(CONFIG_CPU_COPY_V4WB)	+= copypage-v4wb.o
 obj-$(CONFIG_CPU_COPY_FEROCEON)	+= copypage-feroceon.o
@@ -62,8 +55,6 @@ obj-$(CONFIG_CPU_XSCALE)	+= copypage-xscale.o
 obj-$(CONFIG_CPU_XSC3)		+= copypage-xsc3.o
 obj-$(CONFIG_CPU_COPY_FA)	+= copypage-fa.o
 
-CFLAGS_copypage-feroceon.o := -march=armv5te
-
 obj-$(CONFIG_CPU_TLB_V4WT)	+= tlb-v4.o
 obj-$(CONFIG_CPU_TLB_V4WB)	+= tlb-v4wb.o
 obj-$(CONFIG_CPU_TLB_V4WBI)	+= tlb-v4wbi.o
@@ -72,9 +63,6 @@ obj-$(CONFIG_CPU_TLB_V6)	+= tlb-v6.o
 obj-$(CONFIG_CPU_TLB_V7)	+= tlb-v7.o
 obj-$(CONFIG_CPU_TLB_FA)	+= tlb-fa.o
 
-AFLAGS_tlb-v6.o		:=-Wa,-march=armv6
-AFLAGS_tlb-v7.o		:=-Wa,-march=armv7-a
-
 obj-$(CONFIG_CPU_ARM7TDMI)	+= proc-arm7tdmi.o
 obj-$(CONFIG_CPU_ARM720T)	+= proc-arm720.o
 obj-$(CONFIG_CPU_ARM740T)	+= proc-arm740.o
@@ -101,9 +89,6 @@ obj-$(CONFIG_CPU_V6K)		+= proc-v6.o
 obj-$(CONFIG_CPU_V7)		+= proc-v7.o proc-v7-bugs.o
 obj-$(CONFIG_CPU_V7M)		+= proc-v7m.o
 
-AFLAGS_proc-v6.o	:=-Wa,-march=armv6
-AFLAGS_proc-v7.o	:=-Wa,-march=armv7-a
-
 obj-$(CONFIG_OUTER_CACHE)	+= l2c-common.o
 obj-$(CONFIG_CACHE_B15_RAC)	+= cache-b15-rac.o
 obj-$(CONFIG_CACHE_FEROCEON_L2)	+= cache-feroceon-l2.o
diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index c58bf8b43fea..836dc1299243 100644
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -16,6 +16,7 @@
  * abort here if the I-TLB and D-TLB aren't seeing the same
  * picture.  Unfortunately, this does happen.  We live with it.
  */
+	.arch	armv6k
 	.align	5
 ENTRY(v6_early_abort)
 	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S
index f81bceacc660..53fb41c24774 100644
--- a/arch/arm/mm/abort-ev7.S
+++ b/arch/arm/mm/abort-ev7.S
@@ -12,6 +12,7 @@
  *
  * Purpose : obtain information about current aborted instruction.
  */
+	.arch	armv7-a
 	.align	5
 ENTRY(v7_early_abort)
 	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index f0f65eb073e4..250c83bf7158 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -19,6 +19,8 @@
 #define D_CACHE_LINE_SIZE	32
 #define BTB_FLUSH_SIZE		8
 
+.arch armv6
+
 /*
  *	v6_flush_icache_all()
  *
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 7c9499b728c4..127afe2096ba 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -16,6 +16,8 @@
 
 #include "proc-macros.S"
 
+.arch armv7-a
+
 #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
 .globl icache_size
 	.data
diff --git a/arch/arm/mm/cache-v7m.S b/arch/arm/mm/cache-v7m.S
index 1bc3a0a50753..eb60b5e5e2ad 100644
--- a/arch/arm/mm/cache-v7m.S
+++ b/arch/arm/mm/cache-v7m.S
@@ -18,6 +18,8 @@
 
 #include "proc-macros.S"
 
+.arch armv7-m
+
 /* Generic V7M read/write macros for memory mapped cache operations */
 .macro v7m_cache_read, rt, reg
 	movw	\rt, #:lower16:BASEADDR_V7M_SCB + \reg
diff --git a/arch/arm/mm/copypage-feroceon.c b/arch/arm/mm/copypage-feroceon.c
index 064b19e63571..5fc8ef1e665f 100644
--- a/arch/arm/mm/copypage-feroceon.c
+++ b/arch/arm/mm/copypage-feroceon.c
@@ -15,6 +15,7 @@ static void feroceon_copy_user_page(void *kto, const void *kfrom)
 	int tmp;
 
 	asm volatile ("\
+.arch	armv5te					\n\
 1:	ldmia	%1!, {r2 - r7, ip, lr}		\n\
 	pld	[%1, #0]			\n\
 	pld	[%1, #32]			\n\
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index a0618f3e6836..203dff89ab1a 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -32,6 +32,8 @@
 #define TTB_FLAGS_SMP	TTB_RGN_WBWA|TTB_S
 #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
 
+.arch armv6
+
 ENTRY(cpu_v6_proc_init)
 	ret	lr
 
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index 5db029c8f987..0a3083ad19c2 100644
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -24,6 +24,8 @@
 #define TTB_FLAGS_SMP	TTB_IRGN_WBWA|TTB_S|TTB_NOS|TTB_RGN_OC_WBWA
 #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
 
+.arch armv7-a
+
 /*
  *	cpu_v7_switch_mm(pgd_phys, tsk)
  *
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 26d726a08a34..6b4ef9539b68 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -24,6 +24,8 @@
 #include "proc-v7-2level.S"
 #endif
 
+.arch armv7-a
+
 ENTRY(cpu_v7_proc_init)
 	ret	lr
 ENDPROC(cpu_v7_proc_init)
diff --git a/arch/arm/mm/tlb-v6.S b/arch/arm/mm/tlb-v6.S
index 74f4b383afe3..1d91e49b2c2d 100644
--- a/arch/arm/mm/tlb-v6.S
+++ b/arch/arm/mm/tlb-v6.S
@@ -17,6 +17,8 @@
 
 #define HARVARD_TLB
 
+.arch armv6
+
 /*
  *	v6wbi_flush_user_tlb_range(start, end, vma)
  *
diff --git a/arch/arm/mm/tlb-v7.S b/arch/arm/mm/tlb-v7.S
index 87bf4ab17721..35fd6d4f0d03 100644
--- a/arch/arm/mm/tlb-v7.S
+++ b/arch/arm/mm/tlb-v7.S
@@ -16,6 +16,8 @@
 #include <asm/tlbflush.h>
 #include "proc-macros.S"
 
+.arch armv7-a
+
 /*
  *	v7wbi_flush_user_tlb_range(start, end, vma)
  *
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index e148f636c082..ae14ded464a8 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -33,8 +33,6 @@ obj-$(CONFIG_FPGA_DFL_EMIF)	+= dfl-emif.o
 
 ti-emif-sram-objs		:= ti-emif-pm.o ti-emif-sram-pm.o
 
-AFLAGS_ti-emif-sram-pm.o	:=-Wa,-march=armv7-a
-
 $(obj)/ti-emif-sram-pm.o: $(obj)/ti-emif-asm-offsets.h
 
 $(obj)/ti-emif-asm-offsets.h: $(obj)/emif-asm-offsets.s FORCE
diff --git a/drivers/memory/ti-emif-sram-pm.S b/drivers/memory/ti-emif-sram-pm.S
index 9bcac35c3304..d60a8cfd63f3 100644
--- a/drivers/memory/ti-emif-sram-pm.S
+++ b/drivers/memory/ti-emif-sram-pm.S
@@ -28,6 +28,7 @@
 
 	.arm
 	.align 3
+	.arch armv7-a
 
 ENTRY(ti_emif_sram)
 
diff --git a/drivers/soc/bcm/brcmstb/pm/Makefile b/drivers/soc/bcm/brcmstb/pm/Makefile
index 8e10abb14f8b..f849cfa69446 100644
--- a/drivers/soc/bcm/brcmstb/pm/Makefile
+++ b/drivers/soc/bcm/brcmstb/pm/Makefile
@@ -1,4 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_ARM)		+= s2-arm.o pm-arm.o
-AFLAGS_s2-arm.o			:= -march=armv7-a
 obj-$(CONFIG_BMIPS_GENERIC)	+= s2-mips.o s3-mips.o pm-mips.o
diff --git a/drivers/soc/bcm/brcmstb/pm/s2-arm.S b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
index 5f0c4a8ae9df..0d693795de27 100644
--- a/drivers/soc/bcm/brcmstb/pm/s2-arm.S
+++ b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
@@ -8,6 +8,7 @@
 
 #include "pm.h"
 
+	.arch armv7-a
 	.text
 	.align	3
 
-- 
2.38.0.413.g74048e4d9e-goog


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
@ 2022-10-14 20:13   ` Nick Desaulniers
  0 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

Similar to commit a6c30873ee4a ("ARM: 8989/1: use .fpu assembler
directives instead of assembler arguments").

GCC and GNU binutils support setting the "sub arch" via -march=,
-Wa,-march, target function attribute, and .arch assembler directive.

Clang was missing support for -Wa,-march=, but this was implemented in
clang-13.

The behavior of both GCC and Clang is to
prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
sources, but Clang will warn about the -march= being unused.

clang: warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

Since most assembler is non-conditionally assembled with one sub arch
(modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
.arch assembler directive.

Add a few more instances found in compile testing as found by Arnd and
Nathan.

Link: https://github.com/llvm/llvm-project/commit/1d51c699b9e2ebc5bcfdbe85c74cc871426333d4
Link: https://bugs.llvm.org/show_bug.cgi?id=48894
Link: https://github.com/ClangBuiltLinux/linux/issues/1195
Link: https://github.com/ClangBuiltLinux/linux/issues/1315
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
Changes v3 -> v4:
* Add .arch armv7-a to arch/arm/mach-tegra/sleep.S as per Nathan.
  https://github.com/ClangBuiltLinux/linux/issues/1315#issuecomment-1255646893
* Add Nathan's SB tag.

 arch/arm/boot/compressed/Makefile   |  1 -
 arch/arm/common/Makefile            |  2 --
 arch/arm/common/mcpm_head.S         |  2 ++
 arch/arm/common/vlock.S             |  2 ++
 arch/arm/kernel/Makefile            |  2 --
 arch/arm/kernel/hyp-stub.S          |  2 ++
 arch/arm/kernel/swp_emulate.c       |  1 +
 arch/arm/lib/Makefile               |  4 ----
 arch/arm/lib/delay-loop.S           |  4 ++++
 arch/arm/mach-at91/Makefile         |  3 ---
 arch/arm/mach-at91/pm_suspend.S     |  4 ++++
 arch/arm/mach-imx/Makefile          |  3 ---
 arch/arm/mach-imx/headsmp.S         |  2 ++
 arch/arm/mach-imx/resume-imx6.S     |  2 ++
 arch/arm/mach-imx/suspend-imx6.S    |  2 ++
 arch/arm/mach-mvebu/Makefile        |  3 ---
 arch/arm/mach-mvebu/coherency_ll.S  |  1 +
 arch/arm/mach-mvebu/pmsu.c          |  1 +
 arch/arm/mach-npcm/Makefile         |  2 --
 arch/arm/mach-npcm/headsmp.S        |  2 ++
 arch/arm/mach-tegra/Makefile        |  2 --
 arch/arm/mach-tegra/reset-handler.S |  2 ++
 arch/arm/mach-tegra/sleep-tegra20.S |  2 ++
 arch/arm/mach-tegra/sleep-tegra30.S |  2 ++
 arch/arm/mach-tegra/sleep.S         |  2 ++
 arch/arm/mm/Makefile                | 15 ---------------
 arch/arm/mm/abort-ev6.S             |  1 +
 arch/arm/mm/abort-ev7.S             |  1 +
 arch/arm/mm/cache-v6.S              |  2 ++
 arch/arm/mm/cache-v7.S              |  2 ++
 arch/arm/mm/cache-v7m.S             |  2 ++
 arch/arm/mm/copypage-feroceon.c     |  1 +
 arch/arm/mm/proc-v6.S               |  2 ++
 arch/arm/mm/proc-v7-2level.S        |  2 ++
 arch/arm/mm/proc-v7.S               |  2 ++
 arch/arm/mm/tlb-v6.S                |  2 ++
 arch/arm/mm/tlb-v7.S                |  2 ++
 drivers/memory/Makefile             |  2 --
 drivers/memory/ti-emif-sram-pm.S    |  1 +
 drivers/soc/bcm/brcmstb/pm/Makefile |  1 -
 drivers/soc/bcm/brcmstb/pm/s2-arm.S |  1 +
 41 files changed, 54 insertions(+), 40 deletions(-)

diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 41bcbb460fac..e5c80ff42a4f 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -163,4 +163,3 @@ $(obj)/piggy_data: $(obj)/../Image FORCE
 $(obj)/piggy.o: $(obj)/piggy_data
 
 CFLAGS_font.o := -Dstatic=
-AFLAGS_hyp-stub.o := -Wa,-march=armv7-a
diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
index 7bae8cbaafe7..9733381074e0 100644
--- a/arch/arm/common/Makefile
+++ b/arch/arm/common/Makefile
@@ -13,7 +13,5 @@ obj-$(CONFIG_SHARP_SCOOP)	+= scoop.o
 obj-$(CONFIG_CPU_V7)		+= secure_cntvoff.o
 obj-$(CONFIG_MCPM)		+= mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
 CFLAGS_REMOVE_mcpm_entry.o	= -pg
-AFLAGS_mcpm_head.o		:= -march=armv7-a
-AFLAGS_vlock.o			:= -march=armv7-a
 obj-$(CONFIG_BL_SWITCHER)	+= bL_switcher.o
 obj-$(CONFIG_BL_SWITCHER_DUMMY_IF) += bL_switcher_dummy_if.o
diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S
index 291d969bc719..299495c43dfd 100644
--- a/arch/arm/common/mcpm_head.S
+++ b/arch/arm/common/mcpm_head.S
@@ -15,6 +15,8 @@
 
 #include "vlock.h"
 
+.arch armv7-a
+
 .if MCPM_SYNC_CLUSTER_CPUS
 .error "cpus must be the first member of struct mcpm_sync_struct"
 .endif
diff --git a/arch/arm/common/vlock.S b/arch/arm/common/vlock.S
index f1c7fd44f1b1..1fa09c4697ed 100644
--- a/arch/arm/common/vlock.S
+++ b/arch/arm/common/vlock.S
@@ -12,6 +12,8 @@
 #include <linux/linkage.h>
 #include "vlock.h"
 
+.arch armv7-a
+
 /* Select different code if voting flags  can fit in a single word. */
 #if VLOCK_VOTING_SIZE > 4
 #define FEW(x...)
diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
index 48737ec800eb..d53f56d6f840 100644
--- a/arch/arm/kernel/Makefile
+++ b/arch/arm/kernel/Makefile
@@ -70,7 +70,6 @@ obj-$(CONFIG_HAVE_TCM)		+= tcm.o
 obj-$(CONFIG_OF)		+= devtree.o
 obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 obj-$(CONFIG_SWP_EMULATE)	+= swp_emulate.o
-CFLAGS_swp_emulate.o		:= -Wa,-march=armv7-a
 obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
 
 obj-$(CONFIG_CPU_XSCALE)	+= xscale-cp0.o
@@ -99,7 +98,6 @@ CFLAGS_head-inflate-data.o := $(call cc-option,-Wframe-larger-than=10240)
 obj-$(CONFIG_XIP_DEFLATED_DATA) += head-inflate-data.o
 
 obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o
-AFLAGS_hyp-stub.o		:=-Wa,-march=armv7-a
 ifeq ($(CONFIG_ARM_PSCI),y)
 obj-$(CONFIG_SMP)		+= psci_smp.o
 endif
diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
index b699b22a4db1..3a506b9095a5 100644
--- a/arch/arm/kernel/hyp-stub.S
+++ b/arch/arm/kernel/hyp-stub.S
@@ -9,6 +9,8 @@
 #include <asm/assembler.h>
 #include <asm/virt.h>
 
+.arch armv7-a
+
 #ifndef ZIMAGE
 /*
  * For the kernel proper, we need to find out the CPU boot mode long after
diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
index b74bfcf94fb1..fdce83c95acb 100644
--- a/arch/arm/kernel/swp_emulate.c
+++ b/arch/arm/kernel/swp_emulate.c
@@ -34,6 +34,7 @@
  */
 #define __user_swpX_asm(data, addr, res, temp, B)		\
 	__asm__ __volatile__(					\
+	".arch armv7-a\n"					\
 	"0:	ldrex"B"	%2, [%3]\n"			\
 	"1:	strex"B"	%0, %1, [%3]\n"			\
 	"	cmp		%0, #0\n"			\
diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
index 6d2ba454f25b..42fb75c06647 100644
--- a/arch/arm/lib/Makefile
+++ b/arch/arm/lib/Makefile
@@ -36,10 +36,6 @@ else
   lib-y	+= io-readsw-armv4.o io-writesw-armv4.o
 endif
 
-ifeq ($(CONFIG_ARCH_RPC),y)
-  AFLAGS_delay-loop.o		+= -march=armv4
-endif
-
 $(obj)/csumpartialcopy.o:	$(obj)/csumpartialcopygeneric.S
 $(obj)/csumpartialcopyuser.o:	$(obj)/csumpartialcopygeneric.S
 
diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S
index 3ccade0f8130..3ac05177d097 100644
--- a/arch/arm/lib/delay-loop.S
+++ b/arch/arm/lib/delay-loop.S
@@ -8,6 +8,10 @@
 #include <asm/assembler.h>
 #include <asm/delay.h>
 
+#ifdef CONFIG_ARCH_RPC
+		.arch	armv4
+#endif
+
 		.text
 
 .LC0:		.word	loops_per_jiffy
diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
index 0dcc37180588..794bd12ab0a8 100644
--- a/arch/arm/mach-at91/Makefile
+++ b/arch/arm/mach-at91/Makefile
@@ -14,9 +14,6 @@ obj-$(CONFIG_SOC_SAMV7)		+= samv7.o
 # Power Management
 obj-$(CONFIG_ATMEL_PM)		+= pm.o pm_suspend.o
 
-ifeq ($(CONFIG_CPU_V7),y)
-AFLAGS_pm_suspend.o := -march=armv7-a
-endif
 ifeq ($(CONFIG_PM_DEBUG),y)
 CFLAGS_pm.o += -DDEBUG
 endif
diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
index ffed4d949042..78d65809155f 100644
--- a/arch/arm/mach-at91/pm_suspend.S
+++ b/arch/arm/mach-at91/pm_suspend.S
@@ -12,6 +12,10 @@
 #include "pm.h"
 #include "pm_data-offsets.h"
 
+#ifdef CONFIG_CPU_V7
+.arch armv7-a
+#endif
+
 #define	SRAMC_SELF_FRESH_ACTIVE		0x01
 #define	SRAMC_SELF_FRESH_EXIT		0x00
 
diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
index 6fb3965b9ae6..5c650bf40e02 100644
--- a/arch/arm/mach-imx/Makefile
+++ b/arch/arm/mach-imx/Makefile
@@ -34,7 +34,6 @@ obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
 obj-$(CONFIG_HAVE_IMX_MMDC) += mmdc.o
 obj-$(CONFIG_HAVE_IMX_SRC) += src.o
 ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_IMX7D_CA7)$(CONFIG_SOC_LS1021A),)
-AFLAGS_headsmp.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SMP) += headsmp.o platsmp.o
 obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
 endif
@@ -48,12 +47,10 @@ obj-$(CONFIG_SOC_IMX7D_CM4) += mach-imx7d-cm4.o
 obj-$(CONFIG_SOC_IMX7ULP) += mach-imx7ulp.o pm-imx7ulp.o
 
 ifeq ($(CONFIG_SUSPEND),y)
-AFLAGS_suspend-imx6.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SOC_IMX6) += suspend-imx6.o
 obj-$(CONFIG_SOC_IMX53) += suspend-imx53.o
 endif
 ifeq ($(CONFIG_ARM_CPU_SUSPEND),y)
-AFLAGS_resume-imx6.o :=-Wa,-march=armv7-a
 obj-$(CONFIG_SOC_IMX6) += resume-imx6.o
 endif
 obj-$(CONFIG_SOC_IMX6) += pm-imx6.o
diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
index fcba58be8e79..5f9c7b48ae80 100644
--- a/arch/arm/mach-imx/headsmp.S
+++ b/arch/arm/mach-imx/headsmp.S
@@ -8,6 +8,8 @@
 #include <linux/init.h>
 #include <asm/assembler.h>
 
+.arch armv7-a
+
 diag_reg_offset:
 	.word	g_diag_reg - .
 
diff --git a/arch/arm/mach-imx/resume-imx6.S b/arch/arm/mach-imx/resume-imx6.S
index 5bd1ba7ef15b..2c0c5c771251 100644
--- a/arch/arm/mach-imx/resume-imx6.S
+++ b/arch/arm/mach-imx/resume-imx6.S
@@ -9,6 +9,8 @@
 #include <asm/hardware/cache-l2x0.h>
 #include "hardware.h"
 
+.arch armv7-a
+
 /*
  * The following code must assume it is running from physical address
  * where absolute virtual addresses to the data section have to be
diff --git a/arch/arm/mach-imx/suspend-imx6.S b/arch/arm/mach-imx/suspend-imx6.S
index e06f946b75b9..63ccc2d0e920 100644
--- a/arch/arm/mach-imx/suspend-imx6.S
+++ b/arch/arm/mach-imx/suspend-imx6.S
@@ -9,6 +9,8 @@
 #include <asm/hardware/cache-l2x0.h>
 #include "hardware.h"
 
+.arch armv7-a
+
 /*
  * ==================== low level suspend ====================
  *
diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
index c21733cbb4fa..569768a69ffc 100644
--- a/arch/arm/mach-mvebu/Makefile
+++ b/arch/arm/mach-mvebu/Makefile
@@ -1,9 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
 ccflags-y := -I$(srctree)/arch/arm/plat-orion/include
 
-AFLAGS_coherency_ll.o		:= -Wa,-march=armv7-a
-CFLAGS_pmsu.o			:= -march=armv7-a
-
 obj-$(CONFIG_MACH_MVEBU_ANY)	 += system-controller.o mvebu-soc-id.o
 
 ifeq ($(CONFIG_MACH_MVEBU_V7),y)
diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S
index eb81656e32d4..35930e03d9c6 100644
--- a/arch/arm/mach-mvebu/coherency_ll.S
+++ b/arch/arm/mach-mvebu/coherency_ll.S
@@ -20,6 +20,7 @@
 #include <asm/assembler.h>
 #include <asm/cp15.h>
 
+	.arch armv7-a
 	.text
 /*
  * Returns the coherency base address in r1 (r0 is untouched), or 0 if
diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
index af27a7156675..6f366d8c4231 100644
--- a/arch/arm/mach-mvebu/pmsu.c
+++ b/arch/arm/mach-mvebu/pmsu.c
@@ -291,6 +291,7 @@ int armada_370_xp_pmsu_idle_enter(unsigned long deepidle)
 
 	/* Test the CR_C bit and set it if it was cleared */
 	asm volatile(
+	".arch	armv7-a\n\t"
 	"mrc	p15, 0, r0, c1, c0, 0 \n\t"
 	"tst	r0, %0 \n\t"
 	"orreq	r0, r0, #(1 << 2) \n\t"
diff --git a/arch/arm/mach-npcm/Makefile b/arch/arm/mach-npcm/Makefile
index 8d61fcd42fb1..ac83e1caf2ee 100644
--- a/arch/arm/mach-npcm/Makefile
+++ b/arch/arm/mach-npcm/Makefile
@@ -1,6 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0-only
-AFLAGS_headsmp.o		+= -march=armv7-a
-
 obj-$(CONFIG_ARCH_WPCM450)	+= wpcm450.o
 obj-$(CONFIG_ARCH_NPCM7XX)	+= npcm7xx.o
 obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o
diff --git a/arch/arm/mach-npcm/headsmp.S b/arch/arm/mach-npcm/headsmp.S
index c083fe09a07b..84d2b6daaf0b 100644
--- a/arch/arm/mach-npcm/headsmp.S
+++ b/arch/arm/mach-npcm/headsmp.S
@@ -6,6 +6,8 @@
 #include <linux/init.h>
 #include <asm/assembler.h>
 
+.arch armv7-a
+
 /*
  * The boot ROM does not start secondary CPUs in SVC mode, so we need to do that
  * here.
diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
index 07572b5373b8..a2bb55bc0081 100644
--- a/arch/arm/mach-tegra/Makefile
+++ b/arch/arm/mach-tegra/Makefile
@@ -1,6 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-asflags-y				+= -march=armv7-a
-
 obj-y                                   += io.o
 obj-y                                   += irq.o
 obj-y					+= pm.o
diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
index 06ca44b09381..0ea456264f3e 100644
--- a/arch/arm/mach-tegra/reset-handler.S
+++ b/arch/arm/mach-tegra/reset-handler.S
@@ -19,6 +19,8 @@
 
 #define PMC_SCRATCH41	0x140
 
+.arch armv7-a
+
 #ifdef CONFIG_PM_SLEEP
 /*
  *	tegra_resume
diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
index a5a36cce142a..d8cd487a8f63 100644
--- a/arch/arm/mach-tegra/sleep-tegra20.S
+++ b/arch/arm/mach-tegra/sleep-tegra20.S
@@ -47,6 +47,8 @@
 #define PLLM_STORE_MASK			(1 << 1)
 #define PLLP_STORE_MASK			(1 << 2)
 
+.arch armv7-a
+
 .macro test_pll_state, rd, test_mask
 	ldr	\rd, tegra_pll_state
 	tst	\rd, #\test_mask
diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
index 0cc40b6b2ba3..134ea5fe49b2 100644
--- a/arch/arm/mach-tegra/sleep-tegra30.S
+++ b/arch/arm/mach-tegra/sleep-tegra30.S
@@ -78,6 +78,8 @@
 #define PLLX_STORE_MASK			(1 << 4)
 #define PLLM_PMC_STORE_MASK		(1 << 5)
 
+.arch armv7-a
+
 .macro emc_device_mask, rd, base
 	ldr	\rd, [\base, #EMC_ADR_CFG]
 	tst	\rd, #0x1
diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S
index 8f88944831c5..945f2c1474f7 100644
--- a/arch/arm/mach-tegra/sleep.S
+++ b/arch/arm/mach-tegra/sleep.S
@@ -22,6 +22,8 @@
 #define CLK_RESET_CCLK_BURST	0x20
 #define CLK_RESET_CCLK_DIVIDER  0x24
 
+.arch armv7-a
+
 #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
 /*
  * tegra_disable_clean_inv_dcache
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 3510503bc5e6..71b858c9b10c 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -33,9 +33,6 @@ obj-$(CONFIG_CPU_ABRT_EV5TJ)	+= abort-ev5tj.o
 obj-$(CONFIG_CPU_ABRT_EV6)	+= abort-ev6.o
 obj-$(CONFIG_CPU_ABRT_EV7)	+= abort-ev7.o
 
-AFLAGS_abort-ev6.o	:=-Wa,-march=armv6k
-AFLAGS_abort-ev7.o	:=-Wa,-march=armv7-a
-
 obj-$(CONFIG_CPU_PABRT_LEGACY)	+= pabort-legacy.o
 obj-$(CONFIG_CPU_PABRT_V6)	+= pabort-v6.o
 obj-$(CONFIG_CPU_PABRT_V7)	+= pabort-v7.o
@@ -49,10 +46,6 @@ obj-$(CONFIG_CPU_CACHE_FA)	+= cache-fa.o
 obj-$(CONFIG_CPU_CACHE_NOP)	+= cache-nop.o
 obj-$(CONFIG_CPU_CACHE_V7M)	+= cache-v7m.o
 
-AFLAGS_cache-v6.o	:=-Wa,-march=armv6
-AFLAGS_cache-v7.o	:=-Wa,-march=armv7-a
-AFLAGS_cache-v7m.o	:=-Wa,-march=armv7-m
-
 obj-$(CONFIG_CPU_COPY_V4WT)	+= copypage-v4wt.o
 obj-$(CONFIG_CPU_COPY_V4WB)	+= copypage-v4wb.o
 obj-$(CONFIG_CPU_COPY_FEROCEON)	+= copypage-feroceon.o
@@ -62,8 +55,6 @@ obj-$(CONFIG_CPU_XSCALE)	+= copypage-xscale.o
 obj-$(CONFIG_CPU_XSC3)		+= copypage-xsc3.o
 obj-$(CONFIG_CPU_COPY_FA)	+= copypage-fa.o
 
-CFLAGS_copypage-feroceon.o := -march=armv5te
-
 obj-$(CONFIG_CPU_TLB_V4WT)	+= tlb-v4.o
 obj-$(CONFIG_CPU_TLB_V4WB)	+= tlb-v4wb.o
 obj-$(CONFIG_CPU_TLB_V4WBI)	+= tlb-v4wbi.o
@@ -72,9 +63,6 @@ obj-$(CONFIG_CPU_TLB_V6)	+= tlb-v6.o
 obj-$(CONFIG_CPU_TLB_V7)	+= tlb-v7.o
 obj-$(CONFIG_CPU_TLB_FA)	+= tlb-fa.o
 
-AFLAGS_tlb-v6.o		:=-Wa,-march=armv6
-AFLAGS_tlb-v7.o		:=-Wa,-march=armv7-a
-
 obj-$(CONFIG_CPU_ARM7TDMI)	+= proc-arm7tdmi.o
 obj-$(CONFIG_CPU_ARM720T)	+= proc-arm720.o
 obj-$(CONFIG_CPU_ARM740T)	+= proc-arm740.o
@@ -101,9 +89,6 @@ obj-$(CONFIG_CPU_V6K)		+= proc-v6.o
 obj-$(CONFIG_CPU_V7)		+= proc-v7.o proc-v7-bugs.o
 obj-$(CONFIG_CPU_V7M)		+= proc-v7m.o
 
-AFLAGS_proc-v6.o	:=-Wa,-march=armv6
-AFLAGS_proc-v7.o	:=-Wa,-march=armv7-a
-
 obj-$(CONFIG_OUTER_CACHE)	+= l2c-common.o
 obj-$(CONFIG_CACHE_B15_RAC)	+= cache-b15-rac.o
 obj-$(CONFIG_CACHE_FEROCEON_L2)	+= cache-feroceon-l2.o
diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index c58bf8b43fea..836dc1299243 100644
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -16,6 +16,7 @@
  * abort here if the I-TLB and D-TLB aren't seeing the same
  * picture.  Unfortunately, this does happen.  We live with it.
  */
+	.arch	armv6k
 	.align	5
 ENTRY(v6_early_abort)
 	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S
index f81bceacc660..53fb41c24774 100644
--- a/arch/arm/mm/abort-ev7.S
+++ b/arch/arm/mm/abort-ev7.S
@@ -12,6 +12,7 @@
  *
  * Purpose : obtain information about current aborted instruction.
  */
+	.arch	armv7-a
 	.align	5
 ENTRY(v7_early_abort)
 	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
index f0f65eb073e4..250c83bf7158 100644
--- a/arch/arm/mm/cache-v6.S
+++ b/arch/arm/mm/cache-v6.S
@@ -19,6 +19,8 @@
 #define D_CACHE_LINE_SIZE	32
 #define BTB_FLUSH_SIZE		8
 
+.arch armv6
+
 /*
  *	v6_flush_icache_all()
  *
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 7c9499b728c4..127afe2096ba 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -16,6 +16,8 @@
 
 #include "proc-macros.S"
 
+.arch armv7-a
+
 #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
 .globl icache_size
 	.data
diff --git a/arch/arm/mm/cache-v7m.S b/arch/arm/mm/cache-v7m.S
index 1bc3a0a50753..eb60b5e5e2ad 100644
--- a/arch/arm/mm/cache-v7m.S
+++ b/arch/arm/mm/cache-v7m.S
@@ -18,6 +18,8 @@
 
 #include "proc-macros.S"
 
+.arch armv7-m
+
 /* Generic V7M read/write macros for memory mapped cache operations */
 .macro v7m_cache_read, rt, reg
 	movw	\rt, #:lower16:BASEADDR_V7M_SCB + \reg
diff --git a/arch/arm/mm/copypage-feroceon.c b/arch/arm/mm/copypage-feroceon.c
index 064b19e63571..5fc8ef1e665f 100644
--- a/arch/arm/mm/copypage-feroceon.c
+++ b/arch/arm/mm/copypage-feroceon.c
@@ -15,6 +15,7 @@ static void feroceon_copy_user_page(void *kto, const void *kfrom)
 	int tmp;
 
 	asm volatile ("\
+.arch	armv5te					\n\
 1:	ldmia	%1!, {r2 - r7, ip, lr}		\n\
 	pld	[%1, #0]			\n\
 	pld	[%1, #32]			\n\
diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
index a0618f3e6836..203dff89ab1a 100644
--- a/arch/arm/mm/proc-v6.S
+++ b/arch/arm/mm/proc-v6.S
@@ -32,6 +32,8 @@
 #define TTB_FLAGS_SMP	TTB_RGN_WBWA|TTB_S
 #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
 
+.arch armv6
+
 ENTRY(cpu_v6_proc_init)
 	ret	lr
 
diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
index 5db029c8f987..0a3083ad19c2 100644
--- a/arch/arm/mm/proc-v7-2level.S
+++ b/arch/arm/mm/proc-v7-2level.S
@@ -24,6 +24,8 @@
 #define TTB_FLAGS_SMP	TTB_IRGN_WBWA|TTB_S|TTB_NOS|TTB_RGN_OC_WBWA
 #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
 
+.arch armv7-a
+
 /*
  *	cpu_v7_switch_mm(pgd_phys, tsk)
  *
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 26d726a08a34..6b4ef9539b68 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -24,6 +24,8 @@
 #include "proc-v7-2level.S"
 #endif
 
+.arch armv7-a
+
 ENTRY(cpu_v7_proc_init)
 	ret	lr
 ENDPROC(cpu_v7_proc_init)
diff --git a/arch/arm/mm/tlb-v6.S b/arch/arm/mm/tlb-v6.S
index 74f4b383afe3..1d91e49b2c2d 100644
--- a/arch/arm/mm/tlb-v6.S
+++ b/arch/arm/mm/tlb-v6.S
@@ -17,6 +17,8 @@
 
 #define HARVARD_TLB
 
+.arch armv6
+
 /*
  *	v6wbi_flush_user_tlb_range(start, end, vma)
  *
diff --git a/arch/arm/mm/tlb-v7.S b/arch/arm/mm/tlb-v7.S
index 87bf4ab17721..35fd6d4f0d03 100644
--- a/arch/arm/mm/tlb-v7.S
+++ b/arch/arm/mm/tlb-v7.S
@@ -16,6 +16,8 @@
 #include <asm/tlbflush.h>
 #include "proc-macros.S"
 
+.arch armv7-a
+
 /*
  *	v7wbi_flush_user_tlb_range(start, end, vma)
  *
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index e148f636c082..ae14ded464a8 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -33,8 +33,6 @@ obj-$(CONFIG_FPGA_DFL_EMIF)	+= dfl-emif.o
 
 ti-emif-sram-objs		:= ti-emif-pm.o ti-emif-sram-pm.o
 
-AFLAGS_ti-emif-sram-pm.o	:=-Wa,-march=armv7-a
-
 $(obj)/ti-emif-sram-pm.o: $(obj)/ti-emif-asm-offsets.h
 
 $(obj)/ti-emif-asm-offsets.h: $(obj)/emif-asm-offsets.s FORCE
diff --git a/drivers/memory/ti-emif-sram-pm.S b/drivers/memory/ti-emif-sram-pm.S
index 9bcac35c3304..d60a8cfd63f3 100644
--- a/drivers/memory/ti-emif-sram-pm.S
+++ b/drivers/memory/ti-emif-sram-pm.S
@@ -28,6 +28,7 @@
 
 	.arm
 	.align 3
+	.arch armv7-a
 
 ENTRY(ti_emif_sram)
 
diff --git a/drivers/soc/bcm/brcmstb/pm/Makefile b/drivers/soc/bcm/brcmstb/pm/Makefile
index 8e10abb14f8b..f849cfa69446 100644
--- a/drivers/soc/bcm/brcmstb/pm/Makefile
+++ b/drivers/soc/bcm/brcmstb/pm/Makefile
@@ -1,4 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_ARM)		+= s2-arm.o pm-arm.o
-AFLAGS_s2-arm.o			:= -march=armv7-a
 obj-$(CONFIG_BMIPS_GENERIC)	+= s2-mips.o s3-mips.o pm-mips.o
diff --git a/drivers/soc/bcm/brcmstb/pm/s2-arm.S b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
index 5f0c4a8ae9df..0d693795de27 100644
--- a/drivers/soc/bcm/brcmstb/pm/s2-arm.S
+++ b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
@@ -8,6 +8,7 @@
 
 #include "pm.h"
 
+	.arch armv7-a
 	.text
 	.align	3
 
-- 
2.38.0.413.g74048e4d9e-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v4 3/4] ARM: only use -mtp=cp15 for the compiler
  2022-10-14 20:13 ` Nick Desaulniers
@ 2022-10-14 20:13   ` Nick Desaulniers
  -1 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

Avoids an error from the assembler for CONFIG_THUMB2 kernels:

clang-15: error: hardware TLS register is not supported for the thumbv4t
sub-architecture

This flag only makes sense to pass to the compiler, not the assembler.

Perhaps CFLAGS_ABI can be renamed to CPPFLAGS_ABI to reflect that they
will be passed to both the compiler and assembler for sources that
require pre-processing.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/arm/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 8dd943b50b7d..ee888070b2ff 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -111,7 +111,7 @@ CFLAGS_ABI	+= -meabi gnu
 endif
 
 ifeq ($(CONFIG_CURRENT_POINTER_IN_TPIDRURO),y)
-CFLAGS_ABI	+= -mtp=cp15
+KBUILD_CFLAGS	+= -mtp=cp15
 endif
 
 # Accept old syntax despite ".syntax unified"
-- 
2.38.0.413.g74048e4d9e-goog


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v4 3/4] ARM: only use -mtp=cp15 for the compiler
@ 2022-10-14 20:13   ` Nick Desaulniers
  0 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

Avoids an error from the assembler for CONFIG_THUMB2 kernels:

clang-15: error: hardware TLS register is not supported for the thumbv4t
sub-architecture

This flag only makes sense to pass to the compiler, not the assembler.

Perhaps CFLAGS_ABI can be renamed to CPPFLAGS_ABI to reflect that they
will be passed to both the compiler and assembler for sources that
require pre-processing.

Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
 arch/arm/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 8dd943b50b7d..ee888070b2ff 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -111,7 +111,7 @@ CFLAGS_ABI	+= -meabi gnu
 endif
 
 ifeq ($(CONFIG_CURRENT_POINTER_IN_TPIDRURO),y)
-CFLAGS_ABI	+= -mtp=cp15
+KBUILD_CFLAGS	+= -mtp=cp15
 endif
 
 # Accept old syntax despite ".syntax unified"
-- 
2.38.0.413.g74048e4d9e-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v4 4/4] ARM: pass -march= only to compiler
  2022-10-14 20:13 ` Nick Desaulniers
@ 2022-10-14 20:13   ` Nick Desaulniers
  -1 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

When both -march= and -Wa,-march= are specified for assembler or
assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
value but Clang will warn that -march= is unused.

warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

This is the top group of warnings we observe when using clang to
assemble the kernel via `ARCH=arm make LLVM=1`.

Split the arch-y make variable into two, so that -march= flags only get
passed to the compiler, not the assembler. -D flags are added to
KBUILD_CPPFLAGS which is used for both C and assembler-with-cpp sources.

Clang is trying to warn that it doesn't support different values for
-march= and -Wa,-march= (like GCC does, but the kernel doesn't need this)
though the value of the preprocessor define __thumb2__ is based on
-march=. Make sure to re-set __thumb2__ via -D flag for assembler
sources now that we're no longer passing -march= to the assembler. Set
it to a different value than the preprocessor would for -march= in case
-march= gets accidentally re-added to KBUILD_AFLAGS in the future.
Thanks to Ard and Nathan for this suggestion.

Link: https://github.com/ClangBuiltLinux/linux/issues/1315
Link: https://github.com/ClangBuiltLinux/linux/issues/1587
Link: https://github.com/llvm/llvm-project/issues/55656
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
Changes v3 -> v4:
* Add -D__thumb2__=2 to KBUILD_AFLAGS as per in-person discussion with
  Ard and Nathan, and their SB tags.
* Reword commit message.

 arch/arm/Makefile | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index ee888070b2ff..b58998749ead 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -60,21 +60,34 @@ endif
 KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
 
 # This selects which instruction set is used.
+arch-$(CONFIG_CPU_32v7M)	:=-march=armv7-m
+arch-$(CONFIG_CPU_32v7)		:=-march=armv7-a
+arch-$(CONFIG_CPU_32v6)		:=-march=armv6
+# Only override the compiler option if ARMv6. The ARMv6K extensions are
+# always available in ARMv7
+ifeq ($(CONFIG_CPU_32v6),y)
+arch-$(CONFIG_CPU_32v6K)	:=-march=armv6k
+endif
+arch-$(CONFIG_CPU_32v5)		:=-march=armv5te
+arch-$(CONFIG_CPU_32v4T)	:=-march=armv4t
+arch-$(CONFIG_CPU_32v4)		:=-march=armv4
+arch-$(CONFIG_CPU_32v3)		:=-march=armv3m
+
 # Note that GCC does not numerically define an architecture version
 # macro, but instead defines a whole series of macros which makes
 # testing for a specific architecture or later rather impossible.
-arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
-arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
-arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
-# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
+cpp-$(CONFIG_CPU_32v7M)		:=-D__LINUX_ARM_ARCH__=7
+cpp-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7
+cpp-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6
+# Only override the compiler option if ARMv6. The ARMv6K extensions are
 # always available in ARMv7
 ifeq ($(CONFIG_CPU_32v6),y)
-arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
+cpp-$(CONFIG_CPU_32v6K)		:=-D__LINUX_ARM_ARCH__=6
 endif
-arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
-arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
-arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
-arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
+cpp-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5
+cpp-$(CONFIG_CPU_32v4T)		:=-D__LINUX_ARM_ARCH__=4
+cpp-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4
+cpp-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3
 
 # This selects how we optimise for the processor.
 tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
@@ -119,15 +132,16 @@ AFLAGS_NOWARN	:=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
 
 ifeq ($(CONFIG_THUMB2_KERNEL),y)
 CFLAGS_ISA	:=-mthumb -Wa,-mimplicit-it=always $(AFLAGS_NOWARN)
-AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb
+AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb -D__thumb2__=2
 else
 CFLAGS_ISA	:=$(call cc-option,-marm,) $(AFLAGS_NOWARN)
 AFLAGS_ISA	:=$(CFLAGS_ISA)
 endif
 
 # Need -Uarm for gcc < 3.x
+KBUILD_CPPFLAGS	+=$(cpp-y)
 KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
-KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
+KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) -Wa,$(arch-y) $(tune-y) -include asm/unified.h -msoft-float
 
 CHECKFLAGS	+= -D__arm__
 
-- 
2.38.0.413.g74048e4d9e-goog


^ permalink raw reply related	[flat|nested] 26+ messages in thread
* [PATCH v4 4/4] ARM: pass -march= only to compiler
@ 2022-10-14 20:13   ` Nick Desaulniers
  0 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:13 UTC (permalink / raw)
  To: Russell King
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm, Nathan Chancellor,
	Nick Desaulniers

When both -march= and -Wa,-march= are specified for assembler or
assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
value but Clang will warn that -march= is unused.

warning: argument unused during compilation: '-march=armv6k'
[-Wunused-command-line-argument]

This is the top group of warnings we observe when using clang to
assemble the kernel via `ARCH=arm make LLVM=1`.

Split the arch-y make variable into two, so that -march= flags only get
passed to the compiler, not the assembler. -D flags are added to
KBUILD_CPPFLAGS which is used for both C and assembler-with-cpp sources.

Clang is trying to warn that it doesn't support different values for
-march= and -Wa,-march= (like GCC does, but the kernel doesn't need this)
though the value of the preprocessor define __thumb2__ is based on
-march=. Make sure to re-set __thumb2__ via -D flag for assembler
sources now that we're no longer passing -march= to the assembler. Set
it to a different value than the preprocessor would for -march= in case
-march= gets accidentally re-added to KBUILD_AFLAGS in the future.
Thanks to Ard and Nathan for this suggestion.

Link: https://github.com/ClangBuiltLinux/linux/issues/1315
Link: https://github.com/ClangBuiltLinux/linux/issues/1587
Link: https://github.com/llvm/llvm-project/issues/55656
Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Suggested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
---
Changes v3 -> v4:
* Add -D__thumb2__=2 to KBUILD_AFLAGS as per in-person discussion with
  Ard and Nathan, and their SB tags.
* Reword commit message.

 arch/arm/Makefile | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index ee888070b2ff..b58998749ead 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -60,21 +60,34 @@ endif
 KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
 
 # This selects which instruction set is used.
+arch-$(CONFIG_CPU_32v7M)	:=-march=armv7-m
+arch-$(CONFIG_CPU_32v7)		:=-march=armv7-a
+arch-$(CONFIG_CPU_32v6)		:=-march=armv6
+# Only override the compiler option if ARMv6. The ARMv6K extensions are
+# always available in ARMv7
+ifeq ($(CONFIG_CPU_32v6),y)
+arch-$(CONFIG_CPU_32v6K)	:=-march=armv6k
+endif
+arch-$(CONFIG_CPU_32v5)		:=-march=armv5te
+arch-$(CONFIG_CPU_32v4T)	:=-march=armv4t
+arch-$(CONFIG_CPU_32v4)		:=-march=armv4
+arch-$(CONFIG_CPU_32v3)		:=-march=armv3m
+
 # Note that GCC does not numerically define an architecture version
 # macro, but instead defines a whole series of macros which makes
 # testing for a specific architecture or later rather impossible.
-arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
-arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
-arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
-# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
+cpp-$(CONFIG_CPU_32v7M)		:=-D__LINUX_ARM_ARCH__=7
+cpp-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7
+cpp-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6
+# Only override the compiler option if ARMv6. The ARMv6K extensions are
 # always available in ARMv7
 ifeq ($(CONFIG_CPU_32v6),y)
-arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
+cpp-$(CONFIG_CPU_32v6K)		:=-D__LINUX_ARM_ARCH__=6
 endif
-arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
-arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
-arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
-arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
+cpp-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5
+cpp-$(CONFIG_CPU_32v4T)		:=-D__LINUX_ARM_ARCH__=4
+cpp-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4
+cpp-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3
 
 # This selects how we optimise for the processor.
 tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
@@ -119,15 +132,16 @@ AFLAGS_NOWARN	:=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
 
 ifeq ($(CONFIG_THUMB2_KERNEL),y)
 CFLAGS_ISA	:=-mthumb -Wa,-mimplicit-it=always $(AFLAGS_NOWARN)
-AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb
+AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb -D__thumb2__=2
 else
 CFLAGS_ISA	:=$(call cc-option,-marm,) $(AFLAGS_NOWARN)
 AFLAGS_ISA	:=$(CFLAGS_ISA)
 endif
 
 # Need -Uarm for gcc < 3.x
+KBUILD_CPPFLAGS	+=$(cpp-y)
 KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
-KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
+KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) -Wa,$(arch-y) $(tune-y) -include asm/unified.h -msoft-float
 
 CHECKFLAGS	+= -D__arm__
 
-- 
2.38.0.413.g74048e4d9e-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 0/4] pass -march= only to compiler
  2022-10-14 20:13 ` Nick Desaulniers
@ 2022-10-14 20:16   ` Nick Desaulniers
  -1 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:16 UTC (permalink / raw)
  To: Masahiro Yamada
  Cc: Arnd Bergmann, Ard Biesheuvel, Linus Walleij, linux-arm-kernel,
	linux-kernel, llvm, Nathan Chancellor, Russell King

On Fri, Oct 14, 2022 at 1:14 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> When both -march= and -Wa,-march= are specified for assembler or
> assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
> value but Clang will warn that -march= is unused.
>
> warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
>
> This is the top group of warnings we observe when using clang to
> assemble the kernel via `ARCH=arm make LLVM=1`.
>
> Arnd sent a v2 of my previous patch
> https://lore.kernel.org/linux-arm-kernel/20210928154143.2106903-14-arnd@kernel.org/
> I added yet a few more instances I found since then. Nathan pointed out
> a new one too that I've fixed since v3.
>
> Fixing this will allow us to enable
> -Werror=unused-command-line-argument for clang builds.
>
> v3 had an issue wrt. __thumb2__
> https://lore.kernel.org/llvm/CAKwvOdmkd2PxvMUZA=A-72eATGDZkqDj--Bv1W+Xt_K_LWdROA@mail.gmail.com/
> I've incorporated idea from Nathan and Ard on that.

I probably should have made a note: the base of this series is a
little funny.  It's based on today's linux-next (20221014) but with
0a7606a9832ab375a38425a659bda13712ca89ae reverted.  It sounds like
0a7606a9832ab375a38425a659bda13712ca89ae might be dropped from -next
imminently
https://lore.kernel.org/linux-next/CAK7LNARg8OpqLR_71PJV3ZoLuDV8+mz9mphg=CzEeEEMY0G3rw@mail.gmail.com/.
-- 
Thanks,
~Nick Desaulniers

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 0/4] pass -march= only to compiler
@ 2022-10-14 20:16   ` Nick Desaulniers
  0 siblings, 0 replies; 26+ messages in thread
From: Nick Desaulniers @ 2022-10-14 20:16 UTC (permalink / raw)
  To: Masahiro Yamada
  Cc: Arnd Bergmann, Ard Biesheuvel, Linus Walleij, linux-arm-kernel,
	linux-kernel, llvm, Nathan Chancellor, Russell King

On Fri, Oct 14, 2022 at 1:14 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> When both -march= and -Wa,-march= are specified for assembler or
> assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
> value but Clang will warn that -march= is unused.
>
> warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
>
> This is the top group of warnings we observe when using clang to
> assemble the kernel via `ARCH=arm make LLVM=1`.
>
> Arnd sent a v2 of my previous patch
> https://lore.kernel.org/linux-arm-kernel/20210928154143.2106903-14-arnd@kernel.org/
> I added yet a few more instances I found since then. Nathan pointed out
> a new one too that I've fixed since v3.
>
> Fixing this will allow us to enable
> -Werror=unused-command-line-argument for clang builds.
>
> v3 had an issue wrt. __thumb2__
> https://lore.kernel.org/llvm/CAKwvOdmkd2PxvMUZA=A-72eATGDZkqDj--Bv1W+Xt_K_LWdROA@mail.gmail.com/
> I've incorporated idea from Nathan and Ard on that.

I probably should have made a note: the base of this series is a
little funny.  It's based on today's linux-next (20221014) but with
0a7606a9832ab375a38425a659bda13712ca89ae reverted.  It sounds like
0a7606a9832ab375a38425a659bda13712ca89ae might be dropped from -next
imminently
https://lore.kernel.org/linux-next/CAK7LNARg8OpqLR_71PJV3ZoLuDV8+mz9mphg=CzEeEEMY0G3rw@mail.gmail.com/.
-- 
Thanks,
~Nick Desaulniers

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 1/4] ARM: remove lazy evaluation in Makefile
  2022-10-14 20:13   ` Nick Desaulniers
@ 2022-10-14 21:18     ` Nathan Chancellor
  -1 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:18 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:51PM -0700, Nick Desaulniers wrote:
> arch-y and tune-y used lazy evaluation since they used to contain
> cc-option checks. They don't any longer, so just eagerly evaluate these
> command line flags.
> 
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> No change from v3.
> 
>  arch/arm/Makefile | 60 +++++++++++++++++++++--------------------------
>  1 file changed, 27 insertions(+), 33 deletions(-)
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index c846119c448f..8dd943b50b7d 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -63,44 +63,38 @@ KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
>  # Note that GCC does not numerically define an architecture version
>  # macro, but instead defines a whole series of macros which makes
>  # testing for a specific architecture or later rather impossible.
> -arch-$(CONFIG_CPU_32v7M)	=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
> -arch-$(CONFIG_CPU_32v7)		=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
> -arch-$(CONFIG_CPU_32v6)		=-D__LINUX_ARM_ARCH__=6 -march=armv6
> -# Only override the compiler option if ARMv6. The ARMv6K extensions are
> +arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
> +arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
> +arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
> +# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
>  # always available in ARMv7
>  ifeq ($(CONFIG_CPU_32v6),y)
> -arch-$(CONFIG_CPU_32v6K)	=-D__LINUX_ARM_ARCH__=6 -march=armv6k
> +arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
>  endif
> -arch-$(CONFIG_CPU_32v5)		=-D__LINUX_ARM_ARCH__=5 -march=armv5te
> -arch-$(CONFIG_CPU_32v4T)	=-D__LINUX_ARM_ARCH__=4 -march=armv4t
> -arch-$(CONFIG_CPU_32v4)		=-D__LINUX_ARM_ARCH__=4 -march=armv4
> -arch-$(CONFIG_CPU_32v3)		=-D__LINUX_ARM_ARCH__=3 -march=armv3m
> -
> -# Evaluate arch cc-option calls now
> -arch-y := $(arch-y)
> +arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
> +arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
> +arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
> +arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
>  
>  # This selects how we optimise for the processor.
> -tune-$(CONFIG_CPU_ARM7TDMI)	=-mtune=arm7tdmi
> -tune-$(CONFIG_CPU_ARM720T)	=-mtune=arm7tdmi
> -tune-$(CONFIG_CPU_ARM740T)	=-mtune=arm7tdmi
> -tune-$(CONFIG_CPU_ARM9TDMI)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM940T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM946E)	=-mtune=arm9e
> -tune-$(CONFIG_CPU_ARM920T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM922T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM925T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM926T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_FA526)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_SA110)	=-mtune=strongarm110
> -tune-$(CONFIG_CPU_SA1100)	=-mtune=strongarm1100
> -tune-$(CONFIG_CPU_XSCALE)	=-mtune=xscale
> -tune-$(CONFIG_CPU_XSC3)		=-mtune=xscale
> -tune-$(CONFIG_CPU_FEROCEON)	=-mtune=xscale
> -tune-$(CONFIG_CPU_V6)		=-mtune=arm1136j-s
> -tune-$(CONFIG_CPU_V6K)		=-mtune=arm1136j-s
> -
> -# Evaluate tune cc-option calls now
> -tune-y := $(tune-y)
> +tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
> +tune-$(CONFIG_CPU_ARM720T)	:=-mtune=arm7tdmi
> +tune-$(CONFIG_CPU_ARM740T)	:=-mtune=arm7tdmi
> +tune-$(CONFIG_CPU_ARM9TDMI)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM940T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM946E)	:=-mtune=arm9e
> +tune-$(CONFIG_CPU_ARM920T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM922T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM925T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM926T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_FA526)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_SA110)	:=-mtune=strongarm110
> +tune-$(CONFIG_CPU_SA1100)	:=-mtune=strongarm1100
> +tune-$(CONFIG_CPU_XSCALE)	:=-mtune=xscale
> +tune-$(CONFIG_CPU_XSC3)		:=-mtune=xscale
> +tune-$(CONFIG_CPU_FEROCEON)	:=-mtune=xscale
> +tune-$(CONFIG_CPU_V6)		:=-mtune=arm1136j-s
> +tune-$(CONFIG_CPU_V6K)		:=-mtune=arm1136j-s
>  
>  ifeq ($(CONFIG_AEABI),y)
>  CFLAGS_ABI	:=-mabi=aapcs-linux -mfpu=vfp
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 1/4] ARM: remove lazy evaluation in Makefile
@ 2022-10-14 21:18     ` Nathan Chancellor
  0 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:18 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:51PM -0700, Nick Desaulniers wrote:
> arch-y and tune-y used lazy evaluation since they used to contain
> cc-option checks. They don't any longer, so just eagerly evaluate these
> command line flags.
> 
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
> No change from v3.
> 
>  arch/arm/Makefile | 60 +++++++++++++++++++++--------------------------
>  1 file changed, 27 insertions(+), 33 deletions(-)
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index c846119c448f..8dd943b50b7d 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -63,44 +63,38 @@ KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
>  # Note that GCC does not numerically define an architecture version
>  # macro, but instead defines a whole series of macros which makes
>  # testing for a specific architecture or later rather impossible.
> -arch-$(CONFIG_CPU_32v7M)	=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
> -arch-$(CONFIG_CPU_32v7)		=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
> -arch-$(CONFIG_CPU_32v6)		=-D__LINUX_ARM_ARCH__=6 -march=armv6
> -# Only override the compiler option if ARMv6. The ARMv6K extensions are
> +arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
> +arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
> +arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
> +# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
>  # always available in ARMv7
>  ifeq ($(CONFIG_CPU_32v6),y)
> -arch-$(CONFIG_CPU_32v6K)	=-D__LINUX_ARM_ARCH__=6 -march=armv6k
> +arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
>  endif
> -arch-$(CONFIG_CPU_32v5)		=-D__LINUX_ARM_ARCH__=5 -march=armv5te
> -arch-$(CONFIG_CPU_32v4T)	=-D__LINUX_ARM_ARCH__=4 -march=armv4t
> -arch-$(CONFIG_CPU_32v4)		=-D__LINUX_ARM_ARCH__=4 -march=armv4
> -arch-$(CONFIG_CPU_32v3)		=-D__LINUX_ARM_ARCH__=3 -march=armv3m
> -
> -# Evaluate arch cc-option calls now
> -arch-y := $(arch-y)
> +arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
> +arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
> +arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
> +arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
>  
>  # This selects how we optimise for the processor.
> -tune-$(CONFIG_CPU_ARM7TDMI)	=-mtune=arm7tdmi
> -tune-$(CONFIG_CPU_ARM720T)	=-mtune=arm7tdmi
> -tune-$(CONFIG_CPU_ARM740T)	=-mtune=arm7tdmi
> -tune-$(CONFIG_CPU_ARM9TDMI)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM940T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM946E)	=-mtune=arm9e
> -tune-$(CONFIG_CPU_ARM920T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM922T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM925T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_ARM926T)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_FA526)	=-mtune=arm9tdmi
> -tune-$(CONFIG_CPU_SA110)	=-mtune=strongarm110
> -tune-$(CONFIG_CPU_SA1100)	=-mtune=strongarm1100
> -tune-$(CONFIG_CPU_XSCALE)	=-mtune=xscale
> -tune-$(CONFIG_CPU_XSC3)		=-mtune=xscale
> -tune-$(CONFIG_CPU_FEROCEON)	=-mtune=xscale
> -tune-$(CONFIG_CPU_V6)		=-mtune=arm1136j-s
> -tune-$(CONFIG_CPU_V6K)		=-mtune=arm1136j-s
> -
> -# Evaluate tune cc-option calls now
> -tune-y := $(tune-y)
> +tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
> +tune-$(CONFIG_CPU_ARM720T)	:=-mtune=arm7tdmi
> +tune-$(CONFIG_CPU_ARM740T)	:=-mtune=arm7tdmi
> +tune-$(CONFIG_CPU_ARM9TDMI)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM940T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM946E)	:=-mtune=arm9e
> +tune-$(CONFIG_CPU_ARM920T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM922T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM925T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_ARM926T)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_FA526)	:=-mtune=arm9tdmi
> +tune-$(CONFIG_CPU_SA110)	:=-mtune=strongarm110
> +tune-$(CONFIG_CPU_SA1100)	:=-mtune=strongarm1100
> +tune-$(CONFIG_CPU_XSCALE)	:=-mtune=xscale
> +tune-$(CONFIG_CPU_XSC3)		:=-mtune=xscale
> +tune-$(CONFIG_CPU_FEROCEON)	:=-mtune=xscale
> +tune-$(CONFIG_CPU_V6)		:=-mtune=arm1136j-s
> +tune-$(CONFIG_CPU_V6K)		:=-mtune=arm1136j-s
>  
>  ifeq ($(CONFIG_AEABI),y)
>  CFLAGS_ABI	:=-mabi=aapcs-linux -mfpu=vfp
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 
> 

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^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
  2022-10-14 20:13   ` Nick Desaulniers
@ 2022-10-14 21:19     ` Nathan Chancellor
  -1 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:19 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:52PM -0700, Nick Desaulniers wrote:
> Similar to commit a6c30873ee4a ("ARM: 8989/1: use .fpu assembler
> directives instead of assembler arguments").
> 
> GCC and GNU binutils support setting the "sub arch" via -march=,
> -Wa,-march, target function attribute, and .arch assembler directive.
> 
> Clang was missing support for -Wa,-march=, but this was implemented in
> clang-13.
> 
> The behavior of both GCC and Clang is to
> prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
> sources, but Clang will warn about the -march= being unused.
> 
> clang: warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
> 
> Since most assembler is non-conditionally assembled with one sub arch
> (modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
> based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
> conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
> .arch assembler directive.
> 
> Add a few more instances found in compile testing as found by Arnd and
> Nathan.
> 
> Link: https://github.com/llvm/llvm-project/commit/1d51c699b9e2ebc5bcfdbe85c74cc871426333d4
> Link: https://bugs.llvm.org/show_bug.cgi?id=48894
> Link: https://github.com/ClangBuiltLinux/linux/issues/1195
> Link: https://github.com/ClangBuiltLinux/linux/issues/1315
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

This passed through my build matrix on top of commit dca45efbe3c8
("Merge tag 'sound-fix-6.1-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound") and I saw no
additional warnings/errors:

Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
> Changes v3 -> v4:
> * Add .arch armv7-a to arch/arm/mach-tegra/sleep.S as per Nathan.
>   https://github.com/ClangBuiltLinux/linux/issues/1315#issuecomment-1255646893
> * Add Nathan's SB tag.
> 
>  arch/arm/boot/compressed/Makefile   |  1 -
>  arch/arm/common/Makefile            |  2 --
>  arch/arm/common/mcpm_head.S         |  2 ++
>  arch/arm/common/vlock.S             |  2 ++
>  arch/arm/kernel/Makefile            |  2 --
>  arch/arm/kernel/hyp-stub.S          |  2 ++
>  arch/arm/kernel/swp_emulate.c       |  1 +
>  arch/arm/lib/Makefile               |  4 ----
>  arch/arm/lib/delay-loop.S           |  4 ++++
>  arch/arm/mach-at91/Makefile         |  3 ---
>  arch/arm/mach-at91/pm_suspend.S     |  4 ++++
>  arch/arm/mach-imx/Makefile          |  3 ---
>  arch/arm/mach-imx/headsmp.S         |  2 ++
>  arch/arm/mach-imx/resume-imx6.S     |  2 ++
>  arch/arm/mach-imx/suspend-imx6.S    |  2 ++
>  arch/arm/mach-mvebu/Makefile        |  3 ---
>  arch/arm/mach-mvebu/coherency_ll.S  |  1 +
>  arch/arm/mach-mvebu/pmsu.c          |  1 +
>  arch/arm/mach-npcm/Makefile         |  2 --
>  arch/arm/mach-npcm/headsmp.S        |  2 ++
>  arch/arm/mach-tegra/Makefile        |  2 --
>  arch/arm/mach-tegra/reset-handler.S |  2 ++
>  arch/arm/mach-tegra/sleep-tegra20.S |  2 ++
>  arch/arm/mach-tegra/sleep-tegra30.S |  2 ++
>  arch/arm/mach-tegra/sleep.S         |  2 ++
>  arch/arm/mm/Makefile                | 15 ---------------
>  arch/arm/mm/abort-ev6.S             |  1 +
>  arch/arm/mm/abort-ev7.S             |  1 +
>  arch/arm/mm/cache-v6.S              |  2 ++
>  arch/arm/mm/cache-v7.S              |  2 ++
>  arch/arm/mm/cache-v7m.S             |  2 ++
>  arch/arm/mm/copypage-feroceon.c     |  1 +
>  arch/arm/mm/proc-v6.S               |  2 ++
>  arch/arm/mm/proc-v7-2level.S        |  2 ++
>  arch/arm/mm/proc-v7.S               |  2 ++
>  arch/arm/mm/tlb-v6.S                |  2 ++
>  arch/arm/mm/tlb-v7.S                |  2 ++
>  drivers/memory/Makefile             |  2 --
>  drivers/memory/ti-emif-sram-pm.S    |  1 +
>  drivers/soc/bcm/brcmstb/pm/Makefile |  1 -
>  drivers/soc/bcm/brcmstb/pm/s2-arm.S |  1 +
>  41 files changed, 54 insertions(+), 40 deletions(-)
> 
> diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
> index 41bcbb460fac..e5c80ff42a4f 100644
> --- a/arch/arm/boot/compressed/Makefile
> +++ b/arch/arm/boot/compressed/Makefile
> @@ -163,4 +163,3 @@ $(obj)/piggy_data: $(obj)/../Image FORCE
>  $(obj)/piggy.o: $(obj)/piggy_data
>  
>  CFLAGS_font.o := -Dstatic=
> -AFLAGS_hyp-stub.o := -Wa,-march=armv7-a
> diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
> index 7bae8cbaafe7..9733381074e0 100644
> --- a/arch/arm/common/Makefile
> +++ b/arch/arm/common/Makefile
> @@ -13,7 +13,5 @@ obj-$(CONFIG_SHARP_SCOOP)	+= scoop.o
>  obj-$(CONFIG_CPU_V7)		+= secure_cntvoff.o
>  obj-$(CONFIG_MCPM)		+= mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
>  CFLAGS_REMOVE_mcpm_entry.o	= -pg
> -AFLAGS_mcpm_head.o		:= -march=armv7-a
> -AFLAGS_vlock.o			:= -march=armv7-a
>  obj-$(CONFIG_BL_SWITCHER)	+= bL_switcher.o
>  obj-$(CONFIG_BL_SWITCHER_DUMMY_IF) += bL_switcher_dummy_if.o
> diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S
> index 291d969bc719..299495c43dfd 100644
> --- a/arch/arm/common/mcpm_head.S
> +++ b/arch/arm/common/mcpm_head.S
> @@ -15,6 +15,8 @@
>  
>  #include "vlock.h"
>  
> +.arch armv7-a
> +
>  .if MCPM_SYNC_CLUSTER_CPUS
>  .error "cpus must be the first member of struct mcpm_sync_struct"
>  .endif
> diff --git a/arch/arm/common/vlock.S b/arch/arm/common/vlock.S
> index f1c7fd44f1b1..1fa09c4697ed 100644
> --- a/arch/arm/common/vlock.S
> +++ b/arch/arm/common/vlock.S
> @@ -12,6 +12,8 @@
>  #include <linux/linkage.h>
>  #include "vlock.h"
>  
> +.arch armv7-a
> +
>  /* Select different code if voting flags  can fit in a single word. */
>  #if VLOCK_VOTING_SIZE > 4
>  #define FEW(x...)
> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> index 48737ec800eb..d53f56d6f840 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -70,7 +70,6 @@ obj-$(CONFIG_HAVE_TCM)		+= tcm.o
>  obj-$(CONFIG_OF)		+= devtree.o
>  obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>  obj-$(CONFIG_SWP_EMULATE)	+= swp_emulate.o
> -CFLAGS_swp_emulate.o		:= -Wa,-march=armv7-a
>  obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
>  
>  obj-$(CONFIG_CPU_XSCALE)	+= xscale-cp0.o
> @@ -99,7 +98,6 @@ CFLAGS_head-inflate-data.o := $(call cc-option,-Wframe-larger-than=10240)
>  obj-$(CONFIG_XIP_DEFLATED_DATA) += head-inflate-data.o
>  
>  obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o
> -AFLAGS_hyp-stub.o		:=-Wa,-march=armv7-a
>  ifeq ($(CONFIG_ARM_PSCI),y)
>  obj-$(CONFIG_SMP)		+= psci_smp.o
>  endif
> diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
> index b699b22a4db1..3a506b9095a5 100644
> --- a/arch/arm/kernel/hyp-stub.S
> +++ b/arch/arm/kernel/hyp-stub.S
> @@ -9,6 +9,8 @@
>  #include <asm/assembler.h>
>  #include <asm/virt.h>
>  
> +.arch armv7-a
> +
>  #ifndef ZIMAGE
>  /*
>   * For the kernel proper, we need to find out the CPU boot mode long after
> diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
> index b74bfcf94fb1..fdce83c95acb 100644
> --- a/arch/arm/kernel/swp_emulate.c
> +++ b/arch/arm/kernel/swp_emulate.c
> @@ -34,6 +34,7 @@
>   */
>  #define __user_swpX_asm(data, addr, res, temp, B)		\
>  	__asm__ __volatile__(					\
> +	".arch armv7-a\n"					\
>  	"0:	ldrex"B"	%2, [%3]\n"			\
>  	"1:	strex"B"	%0, %1, [%3]\n"			\
>  	"	cmp		%0, #0\n"			\
> diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
> index 6d2ba454f25b..42fb75c06647 100644
> --- a/arch/arm/lib/Makefile
> +++ b/arch/arm/lib/Makefile
> @@ -36,10 +36,6 @@ else
>    lib-y	+= io-readsw-armv4.o io-writesw-armv4.o
>  endif
>  
> -ifeq ($(CONFIG_ARCH_RPC),y)
> -  AFLAGS_delay-loop.o		+= -march=armv4
> -endif
> -
>  $(obj)/csumpartialcopy.o:	$(obj)/csumpartialcopygeneric.S
>  $(obj)/csumpartialcopyuser.o:	$(obj)/csumpartialcopygeneric.S
>  
> diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S
> index 3ccade0f8130..3ac05177d097 100644
> --- a/arch/arm/lib/delay-loop.S
> +++ b/arch/arm/lib/delay-loop.S
> @@ -8,6 +8,10 @@
>  #include <asm/assembler.h>
>  #include <asm/delay.h>
>  
> +#ifdef CONFIG_ARCH_RPC
> +		.arch	armv4
> +#endif
> +
>  		.text
>  
>  .LC0:		.word	loops_per_jiffy
> diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
> index 0dcc37180588..794bd12ab0a8 100644
> --- a/arch/arm/mach-at91/Makefile
> +++ b/arch/arm/mach-at91/Makefile
> @@ -14,9 +14,6 @@ obj-$(CONFIG_SOC_SAMV7)		+= samv7.o
>  # Power Management
>  obj-$(CONFIG_ATMEL_PM)		+= pm.o pm_suspend.o
>  
> -ifeq ($(CONFIG_CPU_V7),y)
> -AFLAGS_pm_suspend.o := -march=armv7-a
> -endif
>  ifeq ($(CONFIG_PM_DEBUG),y)
>  CFLAGS_pm.o += -DDEBUG
>  endif
> diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
> index ffed4d949042..78d65809155f 100644
> --- a/arch/arm/mach-at91/pm_suspend.S
> +++ b/arch/arm/mach-at91/pm_suspend.S
> @@ -12,6 +12,10 @@
>  #include "pm.h"
>  #include "pm_data-offsets.h"
>  
> +#ifdef CONFIG_CPU_V7
> +.arch armv7-a
> +#endif
> +
>  #define	SRAMC_SELF_FRESH_ACTIVE		0x01
>  #define	SRAMC_SELF_FRESH_EXIT		0x00
>  
> diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
> index 6fb3965b9ae6..5c650bf40e02 100644
> --- a/arch/arm/mach-imx/Makefile
> +++ b/arch/arm/mach-imx/Makefile
> @@ -34,7 +34,6 @@ obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
>  obj-$(CONFIG_HAVE_IMX_MMDC) += mmdc.o
>  obj-$(CONFIG_HAVE_IMX_SRC) += src.o
>  ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_IMX7D_CA7)$(CONFIG_SOC_LS1021A),)
> -AFLAGS_headsmp.o :=-Wa,-march=armv7-a
>  obj-$(CONFIG_SMP) += headsmp.o platsmp.o
>  obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
>  endif
> @@ -48,12 +47,10 @@ obj-$(CONFIG_SOC_IMX7D_CM4) += mach-imx7d-cm4.o
>  obj-$(CONFIG_SOC_IMX7ULP) += mach-imx7ulp.o pm-imx7ulp.o
>  
>  ifeq ($(CONFIG_SUSPEND),y)
> -AFLAGS_suspend-imx6.o :=-Wa,-march=armv7-a
>  obj-$(CONFIG_SOC_IMX6) += suspend-imx6.o
>  obj-$(CONFIG_SOC_IMX53) += suspend-imx53.o
>  endif
>  ifeq ($(CONFIG_ARM_CPU_SUSPEND),y)
> -AFLAGS_resume-imx6.o :=-Wa,-march=armv7-a
>  obj-$(CONFIG_SOC_IMX6) += resume-imx6.o
>  endif
>  obj-$(CONFIG_SOC_IMX6) += pm-imx6.o
> diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
> index fcba58be8e79..5f9c7b48ae80 100644
> --- a/arch/arm/mach-imx/headsmp.S
> +++ b/arch/arm/mach-imx/headsmp.S
> @@ -8,6 +8,8 @@
>  #include <linux/init.h>
>  #include <asm/assembler.h>
>  
> +.arch armv7-a
> +
>  diag_reg_offset:
>  	.word	g_diag_reg - .
>  
> diff --git a/arch/arm/mach-imx/resume-imx6.S b/arch/arm/mach-imx/resume-imx6.S
> index 5bd1ba7ef15b..2c0c5c771251 100644
> --- a/arch/arm/mach-imx/resume-imx6.S
> +++ b/arch/arm/mach-imx/resume-imx6.S
> @@ -9,6 +9,8 @@
>  #include <asm/hardware/cache-l2x0.h>
>  #include "hardware.h"
>  
> +.arch armv7-a
> +
>  /*
>   * The following code must assume it is running from physical address
>   * where absolute virtual addresses to the data section have to be
> diff --git a/arch/arm/mach-imx/suspend-imx6.S b/arch/arm/mach-imx/suspend-imx6.S
> index e06f946b75b9..63ccc2d0e920 100644
> --- a/arch/arm/mach-imx/suspend-imx6.S
> +++ b/arch/arm/mach-imx/suspend-imx6.S
> @@ -9,6 +9,8 @@
>  #include <asm/hardware/cache-l2x0.h>
>  #include "hardware.h"
>  
> +.arch armv7-a
> +
>  /*
>   * ==================== low level suspend ====================
>   *
> diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
> index c21733cbb4fa..569768a69ffc 100644
> --- a/arch/arm/mach-mvebu/Makefile
> +++ b/arch/arm/mach-mvebu/Makefile
> @@ -1,9 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  ccflags-y := -I$(srctree)/arch/arm/plat-orion/include
>  
> -AFLAGS_coherency_ll.o		:= -Wa,-march=armv7-a
> -CFLAGS_pmsu.o			:= -march=armv7-a
> -
>  obj-$(CONFIG_MACH_MVEBU_ANY)	 += system-controller.o mvebu-soc-id.o
>  
>  ifeq ($(CONFIG_MACH_MVEBU_V7),y)
> diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S
> index eb81656e32d4..35930e03d9c6 100644
> --- a/arch/arm/mach-mvebu/coherency_ll.S
> +++ b/arch/arm/mach-mvebu/coherency_ll.S
> @@ -20,6 +20,7 @@
>  #include <asm/assembler.h>
>  #include <asm/cp15.h>
>  
> +	.arch armv7-a
>  	.text
>  /*
>   * Returns the coherency base address in r1 (r0 is untouched), or 0 if
> diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
> index af27a7156675..6f366d8c4231 100644
> --- a/arch/arm/mach-mvebu/pmsu.c
> +++ b/arch/arm/mach-mvebu/pmsu.c
> @@ -291,6 +291,7 @@ int armada_370_xp_pmsu_idle_enter(unsigned long deepidle)
>  
>  	/* Test the CR_C bit and set it if it was cleared */
>  	asm volatile(
> +	".arch	armv7-a\n\t"
>  	"mrc	p15, 0, r0, c1, c0, 0 \n\t"
>  	"tst	r0, %0 \n\t"
>  	"orreq	r0, r0, #(1 << 2) \n\t"
> diff --git a/arch/arm/mach-npcm/Makefile b/arch/arm/mach-npcm/Makefile
> index 8d61fcd42fb1..ac83e1caf2ee 100644
> --- a/arch/arm/mach-npcm/Makefile
> +++ b/arch/arm/mach-npcm/Makefile
> @@ -1,6 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0-only
> -AFLAGS_headsmp.o		+= -march=armv7-a
> -
>  obj-$(CONFIG_ARCH_WPCM450)	+= wpcm450.o
>  obj-$(CONFIG_ARCH_NPCM7XX)	+= npcm7xx.o
>  obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o
> diff --git a/arch/arm/mach-npcm/headsmp.S b/arch/arm/mach-npcm/headsmp.S
> index c083fe09a07b..84d2b6daaf0b 100644
> --- a/arch/arm/mach-npcm/headsmp.S
> +++ b/arch/arm/mach-npcm/headsmp.S
> @@ -6,6 +6,8 @@
>  #include <linux/init.h>
>  #include <asm/assembler.h>
>  
> +.arch armv7-a
> +
>  /*
>   * The boot ROM does not start secondary CPUs in SVC mode, so we need to do that
>   * here.
> diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
> index 07572b5373b8..a2bb55bc0081 100644
> --- a/arch/arm/mach-tegra/Makefile
> +++ b/arch/arm/mach-tegra/Makefile
> @@ -1,6 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
> -asflags-y				+= -march=armv7-a
> -
>  obj-y                                   += io.o
>  obj-y                                   += irq.o
>  obj-y					+= pm.o
> diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
> index 06ca44b09381..0ea456264f3e 100644
> --- a/arch/arm/mach-tegra/reset-handler.S
> +++ b/arch/arm/mach-tegra/reset-handler.S
> @@ -19,6 +19,8 @@
>  
>  #define PMC_SCRATCH41	0x140
>  
> +.arch armv7-a
> +
>  #ifdef CONFIG_PM_SLEEP
>  /*
>   *	tegra_resume
> diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
> index a5a36cce142a..d8cd487a8f63 100644
> --- a/arch/arm/mach-tegra/sleep-tegra20.S
> +++ b/arch/arm/mach-tegra/sleep-tegra20.S
> @@ -47,6 +47,8 @@
>  #define PLLM_STORE_MASK			(1 << 1)
>  #define PLLP_STORE_MASK			(1 << 2)
>  
> +.arch armv7-a
> +
>  .macro test_pll_state, rd, test_mask
>  	ldr	\rd, tegra_pll_state
>  	tst	\rd, #\test_mask
> diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
> index 0cc40b6b2ba3..134ea5fe49b2 100644
> --- a/arch/arm/mach-tegra/sleep-tegra30.S
> +++ b/arch/arm/mach-tegra/sleep-tegra30.S
> @@ -78,6 +78,8 @@
>  #define PLLX_STORE_MASK			(1 << 4)
>  #define PLLM_PMC_STORE_MASK		(1 << 5)
>  
> +.arch armv7-a
> +
>  .macro emc_device_mask, rd, base
>  	ldr	\rd, [\base, #EMC_ADR_CFG]
>  	tst	\rd, #0x1
> diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S
> index 8f88944831c5..945f2c1474f7 100644
> --- a/arch/arm/mach-tegra/sleep.S
> +++ b/arch/arm/mach-tegra/sleep.S
> @@ -22,6 +22,8 @@
>  #define CLK_RESET_CCLK_BURST	0x20
>  #define CLK_RESET_CCLK_DIVIDER  0x24
>  
> +.arch armv7-a
> +
>  #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
>  /*
>   * tegra_disable_clean_inv_dcache
> diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
> index 3510503bc5e6..71b858c9b10c 100644
> --- a/arch/arm/mm/Makefile
> +++ b/arch/arm/mm/Makefile
> @@ -33,9 +33,6 @@ obj-$(CONFIG_CPU_ABRT_EV5TJ)	+= abort-ev5tj.o
>  obj-$(CONFIG_CPU_ABRT_EV6)	+= abort-ev6.o
>  obj-$(CONFIG_CPU_ABRT_EV7)	+= abort-ev7.o
>  
> -AFLAGS_abort-ev6.o	:=-Wa,-march=armv6k
> -AFLAGS_abort-ev7.o	:=-Wa,-march=armv7-a
> -
>  obj-$(CONFIG_CPU_PABRT_LEGACY)	+= pabort-legacy.o
>  obj-$(CONFIG_CPU_PABRT_V6)	+= pabort-v6.o
>  obj-$(CONFIG_CPU_PABRT_V7)	+= pabort-v7.o
> @@ -49,10 +46,6 @@ obj-$(CONFIG_CPU_CACHE_FA)	+= cache-fa.o
>  obj-$(CONFIG_CPU_CACHE_NOP)	+= cache-nop.o
>  obj-$(CONFIG_CPU_CACHE_V7M)	+= cache-v7m.o
>  
> -AFLAGS_cache-v6.o	:=-Wa,-march=armv6
> -AFLAGS_cache-v7.o	:=-Wa,-march=armv7-a
> -AFLAGS_cache-v7m.o	:=-Wa,-march=armv7-m
> -
>  obj-$(CONFIG_CPU_COPY_V4WT)	+= copypage-v4wt.o
>  obj-$(CONFIG_CPU_COPY_V4WB)	+= copypage-v4wb.o
>  obj-$(CONFIG_CPU_COPY_FEROCEON)	+= copypage-feroceon.o
> @@ -62,8 +55,6 @@ obj-$(CONFIG_CPU_XSCALE)	+= copypage-xscale.o
>  obj-$(CONFIG_CPU_XSC3)		+= copypage-xsc3.o
>  obj-$(CONFIG_CPU_COPY_FA)	+= copypage-fa.o
>  
> -CFLAGS_copypage-feroceon.o := -march=armv5te
> -
>  obj-$(CONFIG_CPU_TLB_V4WT)	+= tlb-v4.o
>  obj-$(CONFIG_CPU_TLB_V4WB)	+= tlb-v4wb.o
>  obj-$(CONFIG_CPU_TLB_V4WBI)	+= tlb-v4wbi.o
> @@ -72,9 +63,6 @@ obj-$(CONFIG_CPU_TLB_V6)	+= tlb-v6.o
>  obj-$(CONFIG_CPU_TLB_V7)	+= tlb-v7.o
>  obj-$(CONFIG_CPU_TLB_FA)	+= tlb-fa.o
>  
> -AFLAGS_tlb-v6.o		:=-Wa,-march=armv6
> -AFLAGS_tlb-v7.o		:=-Wa,-march=armv7-a
> -
>  obj-$(CONFIG_CPU_ARM7TDMI)	+= proc-arm7tdmi.o
>  obj-$(CONFIG_CPU_ARM720T)	+= proc-arm720.o
>  obj-$(CONFIG_CPU_ARM740T)	+= proc-arm740.o
> @@ -101,9 +89,6 @@ obj-$(CONFIG_CPU_V6K)		+= proc-v6.o
>  obj-$(CONFIG_CPU_V7)		+= proc-v7.o proc-v7-bugs.o
>  obj-$(CONFIG_CPU_V7M)		+= proc-v7m.o
>  
> -AFLAGS_proc-v6.o	:=-Wa,-march=armv6
> -AFLAGS_proc-v7.o	:=-Wa,-march=armv7-a
> -
>  obj-$(CONFIG_OUTER_CACHE)	+= l2c-common.o
>  obj-$(CONFIG_CACHE_B15_RAC)	+= cache-b15-rac.o
>  obj-$(CONFIG_CACHE_FEROCEON_L2)	+= cache-feroceon-l2.o
> diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
> index c58bf8b43fea..836dc1299243 100644
> --- a/arch/arm/mm/abort-ev6.S
> +++ b/arch/arm/mm/abort-ev6.S
> @@ -16,6 +16,7 @@
>   * abort here if the I-TLB and D-TLB aren't seeing the same
>   * picture.  Unfortunately, this does happen.  We live with it.
>   */
> +	.arch	armv6k
>  	.align	5
>  ENTRY(v6_early_abort)
>  	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
> diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S
> index f81bceacc660..53fb41c24774 100644
> --- a/arch/arm/mm/abort-ev7.S
> +++ b/arch/arm/mm/abort-ev7.S
> @@ -12,6 +12,7 @@
>   *
>   * Purpose : obtain information about current aborted instruction.
>   */
> +	.arch	armv7-a
>  	.align	5
>  ENTRY(v7_early_abort)
>  	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
> diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
> index f0f65eb073e4..250c83bf7158 100644
> --- a/arch/arm/mm/cache-v6.S
> +++ b/arch/arm/mm/cache-v6.S
> @@ -19,6 +19,8 @@
>  #define D_CACHE_LINE_SIZE	32
>  #define BTB_FLUSH_SIZE		8
>  
> +.arch armv6
> +
>  /*
>   *	v6_flush_icache_all()
>   *
> diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
> index 7c9499b728c4..127afe2096ba 100644
> --- a/arch/arm/mm/cache-v7.S
> +++ b/arch/arm/mm/cache-v7.S
> @@ -16,6 +16,8 @@
>  
>  #include "proc-macros.S"
>  
> +.arch armv7-a
> +
>  #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
>  .globl icache_size
>  	.data
> diff --git a/arch/arm/mm/cache-v7m.S b/arch/arm/mm/cache-v7m.S
> index 1bc3a0a50753..eb60b5e5e2ad 100644
> --- a/arch/arm/mm/cache-v7m.S
> +++ b/arch/arm/mm/cache-v7m.S
> @@ -18,6 +18,8 @@
>  
>  #include "proc-macros.S"
>  
> +.arch armv7-m
> +
>  /* Generic V7M read/write macros for memory mapped cache operations */
>  .macro v7m_cache_read, rt, reg
>  	movw	\rt, #:lower16:BASEADDR_V7M_SCB + \reg
> diff --git a/arch/arm/mm/copypage-feroceon.c b/arch/arm/mm/copypage-feroceon.c
> index 064b19e63571..5fc8ef1e665f 100644
> --- a/arch/arm/mm/copypage-feroceon.c
> +++ b/arch/arm/mm/copypage-feroceon.c
> @@ -15,6 +15,7 @@ static void feroceon_copy_user_page(void *kto, const void *kfrom)
>  	int tmp;
>  
>  	asm volatile ("\
> +.arch	armv5te					\n\
>  1:	ldmia	%1!, {r2 - r7, ip, lr}		\n\
>  	pld	[%1, #0]			\n\
>  	pld	[%1, #32]			\n\
> diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
> index a0618f3e6836..203dff89ab1a 100644
> --- a/arch/arm/mm/proc-v6.S
> +++ b/arch/arm/mm/proc-v6.S
> @@ -32,6 +32,8 @@
>  #define TTB_FLAGS_SMP	TTB_RGN_WBWA|TTB_S
>  #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
>  
> +.arch armv6
> +
>  ENTRY(cpu_v6_proc_init)
>  	ret	lr
>  
> diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
> index 5db029c8f987..0a3083ad19c2 100644
> --- a/arch/arm/mm/proc-v7-2level.S
> +++ b/arch/arm/mm/proc-v7-2level.S
> @@ -24,6 +24,8 @@
>  #define TTB_FLAGS_SMP	TTB_IRGN_WBWA|TTB_S|TTB_NOS|TTB_RGN_OC_WBWA
>  #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
>  
> +.arch armv7-a
> +
>  /*
>   *	cpu_v7_switch_mm(pgd_phys, tsk)
>   *
> diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
> index 26d726a08a34..6b4ef9539b68 100644
> --- a/arch/arm/mm/proc-v7.S
> +++ b/arch/arm/mm/proc-v7.S
> @@ -24,6 +24,8 @@
>  #include "proc-v7-2level.S"
>  #endif
>  
> +.arch armv7-a
> +
>  ENTRY(cpu_v7_proc_init)
>  	ret	lr
>  ENDPROC(cpu_v7_proc_init)
> diff --git a/arch/arm/mm/tlb-v6.S b/arch/arm/mm/tlb-v6.S
> index 74f4b383afe3..1d91e49b2c2d 100644
> --- a/arch/arm/mm/tlb-v6.S
> +++ b/arch/arm/mm/tlb-v6.S
> @@ -17,6 +17,8 @@
>  
>  #define HARVARD_TLB
>  
> +.arch armv6
> +
>  /*
>   *	v6wbi_flush_user_tlb_range(start, end, vma)
>   *
> diff --git a/arch/arm/mm/tlb-v7.S b/arch/arm/mm/tlb-v7.S
> index 87bf4ab17721..35fd6d4f0d03 100644
> --- a/arch/arm/mm/tlb-v7.S
> +++ b/arch/arm/mm/tlb-v7.S
> @@ -16,6 +16,8 @@
>  #include <asm/tlbflush.h>
>  #include "proc-macros.S"
>  
> +.arch armv7-a
> +
>  /*
>   *	v7wbi_flush_user_tlb_range(start, end, vma)
>   *
> diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
> index e148f636c082..ae14ded464a8 100644
> --- a/drivers/memory/Makefile
> +++ b/drivers/memory/Makefile
> @@ -33,8 +33,6 @@ obj-$(CONFIG_FPGA_DFL_EMIF)	+= dfl-emif.o
>  
>  ti-emif-sram-objs		:= ti-emif-pm.o ti-emif-sram-pm.o
>  
> -AFLAGS_ti-emif-sram-pm.o	:=-Wa,-march=armv7-a
> -
>  $(obj)/ti-emif-sram-pm.o: $(obj)/ti-emif-asm-offsets.h
>  
>  $(obj)/ti-emif-asm-offsets.h: $(obj)/emif-asm-offsets.s FORCE
> diff --git a/drivers/memory/ti-emif-sram-pm.S b/drivers/memory/ti-emif-sram-pm.S
> index 9bcac35c3304..d60a8cfd63f3 100644
> --- a/drivers/memory/ti-emif-sram-pm.S
> +++ b/drivers/memory/ti-emif-sram-pm.S
> @@ -28,6 +28,7 @@
>  
>  	.arm
>  	.align 3
> +	.arch armv7-a
>  
>  ENTRY(ti_emif_sram)
>  
> diff --git a/drivers/soc/bcm/brcmstb/pm/Makefile b/drivers/soc/bcm/brcmstb/pm/Makefile
> index 8e10abb14f8b..f849cfa69446 100644
> --- a/drivers/soc/bcm/brcmstb/pm/Makefile
> +++ b/drivers/soc/bcm/brcmstb/pm/Makefile
> @@ -1,4 +1,3 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  obj-$(CONFIG_ARM)		+= s2-arm.o pm-arm.o
> -AFLAGS_s2-arm.o			:= -march=armv7-a
>  obj-$(CONFIG_BMIPS_GENERIC)	+= s2-mips.o s3-mips.o pm-mips.o
> diff --git a/drivers/soc/bcm/brcmstb/pm/s2-arm.S b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
> index 5f0c4a8ae9df..0d693795de27 100644
> --- a/drivers/soc/bcm/brcmstb/pm/s2-arm.S
> +++ b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
> @@ -8,6 +8,7 @@
>  
>  #include "pm.h"
>  
> +	.arch armv7-a
>  	.text
>  	.align	3
>  
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
@ 2022-10-14 21:19     ` Nathan Chancellor
  0 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:19 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:52PM -0700, Nick Desaulniers wrote:
> Similar to commit a6c30873ee4a ("ARM: 8989/1: use .fpu assembler
> directives instead of assembler arguments").
> 
> GCC and GNU binutils support setting the "sub arch" via -march=,
> -Wa,-march, target function attribute, and .arch assembler directive.
> 
> Clang was missing support for -Wa,-march=, but this was implemented in
> clang-13.
> 
> The behavior of both GCC and Clang is to
> prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
> sources, but Clang will warn about the -march= being unused.
> 
> clang: warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
> 
> Since most assembler is non-conditionally assembled with one sub arch
> (modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
> based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
> conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
> .arch assembler directive.
> 
> Add a few more instances found in compile testing as found by Arnd and
> Nathan.
> 
> Link: https://github.com/llvm/llvm-project/commit/1d51c699b9e2ebc5bcfdbe85c74cc871426333d4
> Link: https://bugs.llvm.org/show_bug.cgi?id=48894
> Link: https://github.com/ClangBuiltLinux/linux/issues/1195
> Link: https://github.com/ClangBuiltLinux/linux/issues/1315
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

This passed through my build matrix on top of commit dca45efbe3c8
("Merge tag 'sound-fix-6.1-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound") and I saw no
additional warnings/errors:

Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
> Changes v3 -> v4:
> * Add .arch armv7-a to arch/arm/mach-tegra/sleep.S as per Nathan.
>   https://github.com/ClangBuiltLinux/linux/issues/1315#issuecomment-1255646893
> * Add Nathan's SB tag.
> 
>  arch/arm/boot/compressed/Makefile   |  1 -
>  arch/arm/common/Makefile            |  2 --
>  arch/arm/common/mcpm_head.S         |  2 ++
>  arch/arm/common/vlock.S             |  2 ++
>  arch/arm/kernel/Makefile            |  2 --
>  arch/arm/kernel/hyp-stub.S          |  2 ++
>  arch/arm/kernel/swp_emulate.c       |  1 +
>  arch/arm/lib/Makefile               |  4 ----
>  arch/arm/lib/delay-loop.S           |  4 ++++
>  arch/arm/mach-at91/Makefile         |  3 ---
>  arch/arm/mach-at91/pm_suspend.S     |  4 ++++
>  arch/arm/mach-imx/Makefile          |  3 ---
>  arch/arm/mach-imx/headsmp.S         |  2 ++
>  arch/arm/mach-imx/resume-imx6.S     |  2 ++
>  arch/arm/mach-imx/suspend-imx6.S    |  2 ++
>  arch/arm/mach-mvebu/Makefile        |  3 ---
>  arch/arm/mach-mvebu/coherency_ll.S  |  1 +
>  arch/arm/mach-mvebu/pmsu.c          |  1 +
>  arch/arm/mach-npcm/Makefile         |  2 --
>  arch/arm/mach-npcm/headsmp.S        |  2 ++
>  arch/arm/mach-tegra/Makefile        |  2 --
>  arch/arm/mach-tegra/reset-handler.S |  2 ++
>  arch/arm/mach-tegra/sleep-tegra20.S |  2 ++
>  arch/arm/mach-tegra/sleep-tegra30.S |  2 ++
>  arch/arm/mach-tegra/sleep.S         |  2 ++
>  arch/arm/mm/Makefile                | 15 ---------------
>  arch/arm/mm/abort-ev6.S             |  1 +
>  arch/arm/mm/abort-ev7.S             |  1 +
>  arch/arm/mm/cache-v6.S              |  2 ++
>  arch/arm/mm/cache-v7.S              |  2 ++
>  arch/arm/mm/cache-v7m.S             |  2 ++
>  arch/arm/mm/copypage-feroceon.c     |  1 +
>  arch/arm/mm/proc-v6.S               |  2 ++
>  arch/arm/mm/proc-v7-2level.S        |  2 ++
>  arch/arm/mm/proc-v7.S               |  2 ++
>  arch/arm/mm/tlb-v6.S                |  2 ++
>  arch/arm/mm/tlb-v7.S                |  2 ++
>  drivers/memory/Makefile             |  2 --
>  drivers/memory/ti-emif-sram-pm.S    |  1 +
>  drivers/soc/bcm/brcmstb/pm/Makefile |  1 -
>  drivers/soc/bcm/brcmstb/pm/s2-arm.S |  1 +
>  41 files changed, 54 insertions(+), 40 deletions(-)
> 
> diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
> index 41bcbb460fac..e5c80ff42a4f 100644
> --- a/arch/arm/boot/compressed/Makefile
> +++ b/arch/arm/boot/compressed/Makefile
> @@ -163,4 +163,3 @@ $(obj)/piggy_data: $(obj)/../Image FORCE
>  $(obj)/piggy.o: $(obj)/piggy_data
>  
>  CFLAGS_font.o := -Dstatic=
> -AFLAGS_hyp-stub.o := -Wa,-march=armv7-a
> diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile
> index 7bae8cbaafe7..9733381074e0 100644
> --- a/arch/arm/common/Makefile
> +++ b/arch/arm/common/Makefile
> @@ -13,7 +13,5 @@ obj-$(CONFIG_SHARP_SCOOP)	+= scoop.o
>  obj-$(CONFIG_CPU_V7)		+= secure_cntvoff.o
>  obj-$(CONFIG_MCPM)		+= mcpm_head.o mcpm_entry.o mcpm_platsmp.o vlock.o
>  CFLAGS_REMOVE_mcpm_entry.o	= -pg
> -AFLAGS_mcpm_head.o		:= -march=armv7-a
> -AFLAGS_vlock.o			:= -march=armv7-a
>  obj-$(CONFIG_BL_SWITCHER)	+= bL_switcher.o
>  obj-$(CONFIG_BL_SWITCHER_DUMMY_IF) += bL_switcher_dummy_if.o
> diff --git a/arch/arm/common/mcpm_head.S b/arch/arm/common/mcpm_head.S
> index 291d969bc719..299495c43dfd 100644
> --- a/arch/arm/common/mcpm_head.S
> +++ b/arch/arm/common/mcpm_head.S
> @@ -15,6 +15,8 @@
>  
>  #include "vlock.h"
>  
> +.arch armv7-a
> +
>  .if MCPM_SYNC_CLUSTER_CPUS
>  .error "cpus must be the first member of struct mcpm_sync_struct"
>  .endif
> diff --git a/arch/arm/common/vlock.S b/arch/arm/common/vlock.S
> index f1c7fd44f1b1..1fa09c4697ed 100644
> --- a/arch/arm/common/vlock.S
> +++ b/arch/arm/common/vlock.S
> @@ -12,6 +12,8 @@
>  #include <linux/linkage.h>
>  #include "vlock.h"
>  
> +.arch armv7-a
> +
>  /* Select different code if voting flags  can fit in a single word. */
>  #if VLOCK_VOTING_SIZE > 4
>  #define FEW(x...)
> diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile
> index 48737ec800eb..d53f56d6f840 100644
> --- a/arch/arm/kernel/Makefile
> +++ b/arch/arm/kernel/Makefile
> @@ -70,7 +70,6 @@ obj-$(CONFIG_HAVE_TCM)		+= tcm.o
>  obj-$(CONFIG_OF)		+= devtree.o
>  obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
>  obj-$(CONFIG_SWP_EMULATE)	+= swp_emulate.o
> -CFLAGS_swp_emulate.o		:= -Wa,-march=armv7-a
>  obj-$(CONFIG_HAVE_HW_BREAKPOINT)	+= hw_breakpoint.o
>  
>  obj-$(CONFIG_CPU_XSCALE)	+= xscale-cp0.o
> @@ -99,7 +98,6 @@ CFLAGS_head-inflate-data.o := $(call cc-option,-Wframe-larger-than=10240)
>  obj-$(CONFIG_XIP_DEFLATED_DATA) += head-inflate-data.o
>  
>  obj-$(CONFIG_ARM_VIRT_EXT)	+= hyp-stub.o
> -AFLAGS_hyp-stub.o		:=-Wa,-march=armv7-a
>  ifeq ($(CONFIG_ARM_PSCI),y)
>  obj-$(CONFIG_SMP)		+= psci_smp.o
>  endif
> diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
> index b699b22a4db1..3a506b9095a5 100644
> --- a/arch/arm/kernel/hyp-stub.S
> +++ b/arch/arm/kernel/hyp-stub.S
> @@ -9,6 +9,8 @@
>  #include <asm/assembler.h>
>  #include <asm/virt.h>
>  
> +.arch armv7-a
> +
>  #ifndef ZIMAGE
>  /*
>   * For the kernel proper, we need to find out the CPU boot mode long after
> diff --git a/arch/arm/kernel/swp_emulate.c b/arch/arm/kernel/swp_emulate.c
> index b74bfcf94fb1..fdce83c95acb 100644
> --- a/arch/arm/kernel/swp_emulate.c
> +++ b/arch/arm/kernel/swp_emulate.c
> @@ -34,6 +34,7 @@
>   */
>  #define __user_swpX_asm(data, addr, res, temp, B)		\
>  	__asm__ __volatile__(					\
> +	".arch armv7-a\n"					\
>  	"0:	ldrex"B"	%2, [%3]\n"			\
>  	"1:	strex"B"	%0, %1, [%3]\n"			\
>  	"	cmp		%0, #0\n"			\
> diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile
> index 6d2ba454f25b..42fb75c06647 100644
> --- a/arch/arm/lib/Makefile
> +++ b/arch/arm/lib/Makefile
> @@ -36,10 +36,6 @@ else
>    lib-y	+= io-readsw-armv4.o io-writesw-armv4.o
>  endif
>  
> -ifeq ($(CONFIG_ARCH_RPC),y)
> -  AFLAGS_delay-loop.o		+= -march=armv4
> -endif
> -
>  $(obj)/csumpartialcopy.o:	$(obj)/csumpartialcopygeneric.S
>  $(obj)/csumpartialcopyuser.o:	$(obj)/csumpartialcopygeneric.S
>  
> diff --git a/arch/arm/lib/delay-loop.S b/arch/arm/lib/delay-loop.S
> index 3ccade0f8130..3ac05177d097 100644
> --- a/arch/arm/lib/delay-loop.S
> +++ b/arch/arm/lib/delay-loop.S
> @@ -8,6 +8,10 @@
>  #include <asm/assembler.h>
>  #include <asm/delay.h>
>  
> +#ifdef CONFIG_ARCH_RPC
> +		.arch	armv4
> +#endif
> +
>  		.text
>  
>  .LC0:		.word	loops_per_jiffy
> diff --git a/arch/arm/mach-at91/Makefile b/arch/arm/mach-at91/Makefile
> index 0dcc37180588..794bd12ab0a8 100644
> --- a/arch/arm/mach-at91/Makefile
> +++ b/arch/arm/mach-at91/Makefile
> @@ -14,9 +14,6 @@ obj-$(CONFIG_SOC_SAMV7)		+= samv7.o
>  # Power Management
>  obj-$(CONFIG_ATMEL_PM)		+= pm.o pm_suspend.o
>  
> -ifeq ($(CONFIG_CPU_V7),y)
> -AFLAGS_pm_suspend.o := -march=armv7-a
> -endif
>  ifeq ($(CONFIG_PM_DEBUG),y)
>  CFLAGS_pm.o += -DDEBUG
>  endif
> diff --git a/arch/arm/mach-at91/pm_suspend.S b/arch/arm/mach-at91/pm_suspend.S
> index ffed4d949042..78d65809155f 100644
> --- a/arch/arm/mach-at91/pm_suspend.S
> +++ b/arch/arm/mach-at91/pm_suspend.S
> @@ -12,6 +12,10 @@
>  #include "pm.h"
>  #include "pm_data-offsets.h"
>  
> +#ifdef CONFIG_CPU_V7
> +.arch armv7-a
> +#endif
> +
>  #define	SRAMC_SELF_FRESH_ACTIVE		0x01
>  #define	SRAMC_SELF_FRESH_EXIT		0x00
>  
> diff --git a/arch/arm/mach-imx/Makefile b/arch/arm/mach-imx/Makefile
> index 6fb3965b9ae6..5c650bf40e02 100644
> --- a/arch/arm/mach-imx/Makefile
> +++ b/arch/arm/mach-imx/Makefile
> @@ -34,7 +34,6 @@ obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
>  obj-$(CONFIG_HAVE_IMX_MMDC) += mmdc.o
>  obj-$(CONFIG_HAVE_IMX_SRC) += src.o
>  ifneq ($(CONFIG_SOC_IMX6)$(CONFIG_SOC_IMX7D_CA7)$(CONFIG_SOC_LS1021A),)
> -AFLAGS_headsmp.o :=-Wa,-march=armv7-a
>  obj-$(CONFIG_SMP) += headsmp.o platsmp.o
>  obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o
>  endif
> @@ -48,12 +47,10 @@ obj-$(CONFIG_SOC_IMX7D_CM4) += mach-imx7d-cm4.o
>  obj-$(CONFIG_SOC_IMX7ULP) += mach-imx7ulp.o pm-imx7ulp.o
>  
>  ifeq ($(CONFIG_SUSPEND),y)
> -AFLAGS_suspend-imx6.o :=-Wa,-march=armv7-a
>  obj-$(CONFIG_SOC_IMX6) += suspend-imx6.o
>  obj-$(CONFIG_SOC_IMX53) += suspend-imx53.o
>  endif
>  ifeq ($(CONFIG_ARM_CPU_SUSPEND),y)
> -AFLAGS_resume-imx6.o :=-Wa,-march=armv7-a
>  obj-$(CONFIG_SOC_IMX6) += resume-imx6.o
>  endif
>  obj-$(CONFIG_SOC_IMX6) += pm-imx6.o
> diff --git a/arch/arm/mach-imx/headsmp.S b/arch/arm/mach-imx/headsmp.S
> index fcba58be8e79..5f9c7b48ae80 100644
> --- a/arch/arm/mach-imx/headsmp.S
> +++ b/arch/arm/mach-imx/headsmp.S
> @@ -8,6 +8,8 @@
>  #include <linux/init.h>
>  #include <asm/assembler.h>
>  
> +.arch armv7-a
> +
>  diag_reg_offset:
>  	.word	g_diag_reg - .
>  
> diff --git a/arch/arm/mach-imx/resume-imx6.S b/arch/arm/mach-imx/resume-imx6.S
> index 5bd1ba7ef15b..2c0c5c771251 100644
> --- a/arch/arm/mach-imx/resume-imx6.S
> +++ b/arch/arm/mach-imx/resume-imx6.S
> @@ -9,6 +9,8 @@
>  #include <asm/hardware/cache-l2x0.h>
>  #include "hardware.h"
>  
> +.arch armv7-a
> +
>  /*
>   * The following code must assume it is running from physical address
>   * where absolute virtual addresses to the data section have to be
> diff --git a/arch/arm/mach-imx/suspend-imx6.S b/arch/arm/mach-imx/suspend-imx6.S
> index e06f946b75b9..63ccc2d0e920 100644
> --- a/arch/arm/mach-imx/suspend-imx6.S
> +++ b/arch/arm/mach-imx/suspend-imx6.S
> @@ -9,6 +9,8 @@
>  #include <asm/hardware/cache-l2x0.h>
>  #include "hardware.h"
>  
> +.arch armv7-a
> +
>  /*
>   * ==================== low level suspend ====================
>   *
> diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
> index c21733cbb4fa..569768a69ffc 100644
> --- a/arch/arm/mach-mvebu/Makefile
> +++ b/arch/arm/mach-mvebu/Makefile
> @@ -1,9 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  ccflags-y := -I$(srctree)/arch/arm/plat-orion/include
>  
> -AFLAGS_coherency_ll.o		:= -Wa,-march=armv7-a
> -CFLAGS_pmsu.o			:= -march=armv7-a
> -
>  obj-$(CONFIG_MACH_MVEBU_ANY)	 += system-controller.o mvebu-soc-id.o
>  
>  ifeq ($(CONFIG_MACH_MVEBU_V7),y)
> diff --git a/arch/arm/mach-mvebu/coherency_ll.S b/arch/arm/mach-mvebu/coherency_ll.S
> index eb81656e32d4..35930e03d9c6 100644
> --- a/arch/arm/mach-mvebu/coherency_ll.S
> +++ b/arch/arm/mach-mvebu/coherency_ll.S
> @@ -20,6 +20,7 @@
>  #include <asm/assembler.h>
>  #include <asm/cp15.h>
>  
> +	.arch armv7-a
>  	.text
>  /*
>   * Returns the coherency base address in r1 (r0 is untouched), or 0 if
> diff --git a/arch/arm/mach-mvebu/pmsu.c b/arch/arm/mach-mvebu/pmsu.c
> index af27a7156675..6f366d8c4231 100644
> --- a/arch/arm/mach-mvebu/pmsu.c
> +++ b/arch/arm/mach-mvebu/pmsu.c
> @@ -291,6 +291,7 @@ int armada_370_xp_pmsu_idle_enter(unsigned long deepidle)
>  
>  	/* Test the CR_C bit and set it if it was cleared */
>  	asm volatile(
> +	".arch	armv7-a\n\t"
>  	"mrc	p15, 0, r0, c1, c0, 0 \n\t"
>  	"tst	r0, %0 \n\t"
>  	"orreq	r0, r0, #(1 << 2) \n\t"
> diff --git a/arch/arm/mach-npcm/Makefile b/arch/arm/mach-npcm/Makefile
> index 8d61fcd42fb1..ac83e1caf2ee 100644
> --- a/arch/arm/mach-npcm/Makefile
> +++ b/arch/arm/mach-npcm/Makefile
> @@ -1,6 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0-only
> -AFLAGS_headsmp.o		+= -march=armv7-a
> -
>  obj-$(CONFIG_ARCH_WPCM450)	+= wpcm450.o
>  obj-$(CONFIG_ARCH_NPCM7XX)	+= npcm7xx.o
>  obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o
> diff --git a/arch/arm/mach-npcm/headsmp.S b/arch/arm/mach-npcm/headsmp.S
> index c083fe09a07b..84d2b6daaf0b 100644
> --- a/arch/arm/mach-npcm/headsmp.S
> +++ b/arch/arm/mach-npcm/headsmp.S
> @@ -6,6 +6,8 @@
>  #include <linux/init.h>
>  #include <asm/assembler.h>
>  
> +.arch armv7-a
> +
>  /*
>   * The boot ROM does not start secondary CPUs in SVC mode, so we need to do that
>   * here.
> diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
> index 07572b5373b8..a2bb55bc0081 100644
> --- a/arch/arm/mach-tegra/Makefile
> +++ b/arch/arm/mach-tegra/Makefile
> @@ -1,6 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0
> -asflags-y				+= -march=armv7-a
> -
>  obj-y                                   += io.o
>  obj-y                                   += irq.o
>  obj-y					+= pm.o
> diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S
> index 06ca44b09381..0ea456264f3e 100644
> --- a/arch/arm/mach-tegra/reset-handler.S
> +++ b/arch/arm/mach-tegra/reset-handler.S
> @@ -19,6 +19,8 @@
>  
>  #define PMC_SCRATCH41	0x140
>  
> +.arch armv7-a
> +
>  #ifdef CONFIG_PM_SLEEP
>  /*
>   *	tegra_resume
> diff --git a/arch/arm/mach-tegra/sleep-tegra20.S b/arch/arm/mach-tegra/sleep-tegra20.S
> index a5a36cce142a..d8cd487a8f63 100644
> --- a/arch/arm/mach-tegra/sleep-tegra20.S
> +++ b/arch/arm/mach-tegra/sleep-tegra20.S
> @@ -47,6 +47,8 @@
>  #define PLLM_STORE_MASK			(1 << 1)
>  #define PLLP_STORE_MASK			(1 << 2)
>  
> +.arch armv7-a
> +
>  .macro test_pll_state, rd, test_mask
>  	ldr	\rd, tegra_pll_state
>  	tst	\rd, #\test_mask
> diff --git a/arch/arm/mach-tegra/sleep-tegra30.S b/arch/arm/mach-tegra/sleep-tegra30.S
> index 0cc40b6b2ba3..134ea5fe49b2 100644
> --- a/arch/arm/mach-tegra/sleep-tegra30.S
> +++ b/arch/arm/mach-tegra/sleep-tegra30.S
> @@ -78,6 +78,8 @@
>  #define PLLX_STORE_MASK			(1 << 4)
>  #define PLLM_PMC_STORE_MASK		(1 << 5)
>  
> +.arch armv7-a
> +
>  .macro emc_device_mask, rd, base
>  	ldr	\rd, [\base, #EMC_ADR_CFG]
>  	tst	\rd, #0x1
> diff --git a/arch/arm/mach-tegra/sleep.S b/arch/arm/mach-tegra/sleep.S
> index 8f88944831c5..945f2c1474f7 100644
> --- a/arch/arm/mach-tegra/sleep.S
> +++ b/arch/arm/mach-tegra/sleep.S
> @@ -22,6 +22,8 @@
>  #define CLK_RESET_CCLK_BURST	0x20
>  #define CLK_RESET_CCLK_DIVIDER  0x24
>  
> +.arch armv7-a
> +
>  #if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
>  /*
>   * tegra_disable_clean_inv_dcache
> diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
> index 3510503bc5e6..71b858c9b10c 100644
> --- a/arch/arm/mm/Makefile
> +++ b/arch/arm/mm/Makefile
> @@ -33,9 +33,6 @@ obj-$(CONFIG_CPU_ABRT_EV5TJ)	+= abort-ev5tj.o
>  obj-$(CONFIG_CPU_ABRT_EV6)	+= abort-ev6.o
>  obj-$(CONFIG_CPU_ABRT_EV7)	+= abort-ev7.o
>  
> -AFLAGS_abort-ev6.o	:=-Wa,-march=armv6k
> -AFLAGS_abort-ev7.o	:=-Wa,-march=armv7-a
> -
>  obj-$(CONFIG_CPU_PABRT_LEGACY)	+= pabort-legacy.o
>  obj-$(CONFIG_CPU_PABRT_V6)	+= pabort-v6.o
>  obj-$(CONFIG_CPU_PABRT_V7)	+= pabort-v7.o
> @@ -49,10 +46,6 @@ obj-$(CONFIG_CPU_CACHE_FA)	+= cache-fa.o
>  obj-$(CONFIG_CPU_CACHE_NOP)	+= cache-nop.o
>  obj-$(CONFIG_CPU_CACHE_V7M)	+= cache-v7m.o
>  
> -AFLAGS_cache-v6.o	:=-Wa,-march=armv6
> -AFLAGS_cache-v7.o	:=-Wa,-march=armv7-a
> -AFLAGS_cache-v7m.o	:=-Wa,-march=armv7-m
> -
>  obj-$(CONFIG_CPU_COPY_V4WT)	+= copypage-v4wt.o
>  obj-$(CONFIG_CPU_COPY_V4WB)	+= copypage-v4wb.o
>  obj-$(CONFIG_CPU_COPY_FEROCEON)	+= copypage-feroceon.o
> @@ -62,8 +55,6 @@ obj-$(CONFIG_CPU_XSCALE)	+= copypage-xscale.o
>  obj-$(CONFIG_CPU_XSC3)		+= copypage-xsc3.o
>  obj-$(CONFIG_CPU_COPY_FA)	+= copypage-fa.o
>  
> -CFLAGS_copypage-feroceon.o := -march=armv5te
> -
>  obj-$(CONFIG_CPU_TLB_V4WT)	+= tlb-v4.o
>  obj-$(CONFIG_CPU_TLB_V4WB)	+= tlb-v4wb.o
>  obj-$(CONFIG_CPU_TLB_V4WBI)	+= tlb-v4wbi.o
> @@ -72,9 +63,6 @@ obj-$(CONFIG_CPU_TLB_V6)	+= tlb-v6.o
>  obj-$(CONFIG_CPU_TLB_V7)	+= tlb-v7.o
>  obj-$(CONFIG_CPU_TLB_FA)	+= tlb-fa.o
>  
> -AFLAGS_tlb-v6.o		:=-Wa,-march=armv6
> -AFLAGS_tlb-v7.o		:=-Wa,-march=armv7-a
> -
>  obj-$(CONFIG_CPU_ARM7TDMI)	+= proc-arm7tdmi.o
>  obj-$(CONFIG_CPU_ARM720T)	+= proc-arm720.o
>  obj-$(CONFIG_CPU_ARM740T)	+= proc-arm740.o
> @@ -101,9 +89,6 @@ obj-$(CONFIG_CPU_V6K)		+= proc-v6.o
>  obj-$(CONFIG_CPU_V7)		+= proc-v7.o proc-v7-bugs.o
>  obj-$(CONFIG_CPU_V7M)		+= proc-v7m.o
>  
> -AFLAGS_proc-v6.o	:=-Wa,-march=armv6
> -AFLAGS_proc-v7.o	:=-Wa,-march=armv7-a
> -
>  obj-$(CONFIG_OUTER_CACHE)	+= l2c-common.o
>  obj-$(CONFIG_CACHE_B15_RAC)	+= cache-b15-rac.o
>  obj-$(CONFIG_CACHE_FEROCEON_L2)	+= cache-feroceon-l2.o
> diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
> index c58bf8b43fea..836dc1299243 100644
> --- a/arch/arm/mm/abort-ev6.S
> +++ b/arch/arm/mm/abort-ev6.S
> @@ -16,6 +16,7 @@
>   * abort here if the I-TLB and D-TLB aren't seeing the same
>   * picture.  Unfortunately, this does happen.  We live with it.
>   */
> +	.arch	armv6k
>  	.align	5
>  ENTRY(v6_early_abort)
>  	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
> diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S
> index f81bceacc660..53fb41c24774 100644
> --- a/arch/arm/mm/abort-ev7.S
> +++ b/arch/arm/mm/abort-ev7.S
> @@ -12,6 +12,7 @@
>   *
>   * Purpose : obtain information about current aborted instruction.
>   */
> +	.arch	armv7-a
>  	.align	5
>  ENTRY(v7_early_abort)
>  	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
> diff --git a/arch/arm/mm/cache-v6.S b/arch/arm/mm/cache-v6.S
> index f0f65eb073e4..250c83bf7158 100644
> --- a/arch/arm/mm/cache-v6.S
> +++ b/arch/arm/mm/cache-v6.S
> @@ -19,6 +19,8 @@
>  #define D_CACHE_LINE_SIZE	32
>  #define BTB_FLUSH_SIZE		8
>  
> +.arch armv6
> +
>  /*
>   *	v6_flush_icache_all()
>   *
> diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
> index 7c9499b728c4..127afe2096ba 100644
> --- a/arch/arm/mm/cache-v7.S
> +++ b/arch/arm/mm/cache-v7.S
> @@ -16,6 +16,8 @@
>  
>  #include "proc-macros.S"
>  
> +.arch armv7-a
> +
>  #ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
>  .globl icache_size
>  	.data
> diff --git a/arch/arm/mm/cache-v7m.S b/arch/arm/mm/cache-v7m.S
> index 1bc3a0a50753..eb60b5e5e2ad 100644
> --- a/arch/arm/mm/cache-v7m.S
> +++ b/arch/arm/mm/cache-v7m.S
> @@ -18,6 +18,8 @@
>  
>  #include "proc-macros.S"
>  
> +.arch armv7-m
> +
>  /* Generic V7M read/write macros for memory mapped cache operations */
>  .macro v7m_cache_read, rt, reg
>  	movw	\rt, #:lower16:BASEADDR_V7M_SCB + \reg
> diff --git a/arch/arm/mm/copypage-feroceon.c b/arch/arm/mm/copypage-feroceon.c
> index 064b19e63571..5fc8ef1e665f 100644
> --- a/arch/arm/mm/copypage-feroceon.c
> +++ b/arch/arm/mm/copypage-feroceon.c
> @@ -15,6 +15,7 @@ static void feroceon_copy_user_page(void *kto, const void *kfrom)
>  	int tmp;
>  
>  	asm volatile ("\
> +.arch	armv5te					\n\
>  1:	ldmia	%1!, {r2 - r7, ip, lr}		\n\
>  	pld	[%1, #0]			\n\
>  	pld	[%1, #32]			\n\
> diff --git a/arch/arm/mm/proc-v6.S b/arch/arm/mm/proc-v6.S
> index a0618f3e6836..203dff89ab1a 100644
> --- a/arch/arm/mm/proc-v6.S
> +++ b/arch/arm/mm/proc-v6.S
> @@ -32,6 +32,8 @@
>  #define TTB_FLAGS_SMP	TTB_RGN_WBWA|TTB_S
>  #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
>  
> +.arch armv6
> +
>  ENTRY(cpu_v6_proc_init)
>  	ret	lr
>  
> diff --git a/arch/arm/mm/proc-v7-2level.S b/arch/arm/mm/proc-v7-2level.S
> index 5db029c8f987..0a3083ad19c2 100644
> --- a/arch/arm/mm/proc-v7-2level.S
> +++ b/arch/arm/mm/proc-v7-2level.S
> @@ -24,6 +24,8 @@
>  #define TTB_FLAGS_SMP	TTB_IRGN_WBWA|TTB_S|TTB_NOS|TTB_RGN_OC_WBWA
>  #define PMD_FLAGS_SMP	PMD_SECT_WBWA|PMD_SECT_S
>  
> +.arch armv7-a
> +
>  /*
>   *	cpu_v7_switch_mm(pgd_phys, tsk)
>   *
> diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
> index 26d726a08a34..6b4ef9539b68 100644
> --- a/arch/arm/mm/proc-v7.S
> +++ b/arch/arm/mm/proc-v7.S
> @@ -24,6 +24,8 @@
>  #include "proc-v7-2level.S"
>  #endif
>  
> +.arch armv7-a
> +
>  ENTRY(cpu_v7_proc_init)
>  	ret	lr
>  ENDPROC(cpu_v7_proc_init)
> diff --git a/arch/arm/mm/tlb-v6.S b/arch/arm/mm/tlb-v6.S
> index 74f4b383afe3..1d91e49b2c2d 100644
> --- a/arch/arm/mm/tlb-v6.S
> +++ b/arch/arm/mm/tlb-v6.S
> @@ -17,6 +17,8 @@
>  
>  #define HARVARD_TLB
>  
> +.arch armv6
> +
>  /*
>   *	v6wbi_flush_user_tlb_range(start, end, vma)
>   *
> diff --git a/arch/arm/mm/tlb-v7.S b/arch/arm/mm/tlb-v7.S
> index 87bf4ab17721..35fd6d4f0d03 100644
> --- a/arch/arm/mm/tlb-v7.S
> +++ b/arch/arm/mm/tlb-v7.S
> @@ -16,6 +16,8 @@
>  #include <asm/tlbflush.h>
>  #include "proc-macros.S"
>  
> +.arch armv7-a
> +
>  /*
>   *	v7wbi_flush_user_tlb_range(start, end, vma)
>   *
> diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
> index e148f636c082..ae14ded464a8 100644
> --- a/drivers/memory/Makefile
> +++ b/drivers/memory/Makefile
> @@ -33,8 +33,6 @@ obj-$(CONFIG_FPGA_DFL_EMIF)	+= dfl-emif.o
>  
>  ti-emif-sram-objs		:= ti-emif-pm.o ti-emif-sram-pm.o
>  
> -AFLAGS_ti-emif-sram-pm.o	:=-Wa,-march=armv7-a
> -
>  $(obj)/ti-emif-sram-pm.o: $(obj)/ti-emif-asm-offsets.h
>  
>  $(obj)/ti-emif-asm-offsets.h: $(obj)/emif-asm-offsets.s FORCE
> diff --git a/drivers/memory/ti-emif-sram-pm.S b/drivers/memory/ti-emif-sram-pm.S
> index 9bcac35c3304..d60a8cfd63f3 100644
> --- a/drivers/memory/ti-emif-sram-pm.S
> +++ b/drivers/memory/ti-emif-sram-pm.S
> @@ -28,6 +28,7 @@
>  
>  	.arm
>  	.align 3
> +	.arch armv7-a
>  
>  ENTRY(ti_emif_sram)
>  
> diff --git a/drivers/soc/bcm/brcmstb/pm/Makefile b/drivers/soc/bcm/brcmstb/pm/Makefile
> index 8e10abb14f8b..f849cfa69446 100644
> --- a/drivers/soc/bcm/brcmstb/pm/Makefile
> +++ b/drivers/soc/bcm/brcmstb/pm/Makefile
> @@ -1,4 +1,3 @@
>  # SPDX-License-Identifier: GPL-2.0-only
>  obj-$(CONFIG_ARM)		+= s2-arm.o pm-arm.o
> -AFLAGS_s2-arm.o			:= -march=armv7-a
>  obj-$(CONFIG_BMIPS_GENERIC)	+= s2-mips.o s3-mips.o pm-mips.o
> diff --git a/drivers/soc/bcm/brcmstb/pm/s2-arm.S b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
> index 5f0c4a8ae9df..0d693795de27 100644
> --- a/drivers/soc/bcm/brcmstb/pm/s2-arm.S
> +++ b/drivers/soc/bcm/brcmstb/pm/s2-arm.S
> @@ -8,6 +8,7 @@
>  
>  #include "pm.h"
>  
> +	.arch armv7-a
>  	.text
>  	.align	3
>  
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 3/4] ARM: only use -mtp=cp15 for the compiler
  2022-10-14 20:13   ` Nick Desaulniers
@ 2022-10-14 21:20     ` Nathan Chancellor
  -1 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:20 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:53PM -0700, Nick Desaulniers wrote:
> Avoids an error from the assembler for CONFIG_THUMB2 kernels:
> 
> clang-15: error: hardware TLS register is not supported for the thumbv4t
> sub-architecture
> 
> This flag only makes sense to pass to the compiler, not the assembler.
> 
> Perhaps CFLAGS_ABI can be renamed to CPPFLAGS_ABI to reflect that they
> will be passed to both the compiler and assembler for sources that
> require pre-processing.
> 
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  arch/arm/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 8dd943b50b7d..ee888070b2ff 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -111,7 +111,7 @@ CFLAGS_ABI	+= -meabi gnu
>  endif
>  
>  ifeq ($(CONFIG_CURRENT_POINTER_IN_TPIDRURO),y)
> -CFLAGS_ABI	+= -mtp=cp15
> +KBUILD_CFLAGS	+= -mtp=cp15
>  endif
>  
>  # Accept old syntax despite ".syntax unified"
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 3/4] ARM: only use -mtp=cp15 for the compiler
@ 2022-10-14 21:20     ` Nathan Chancellor
  0 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:20 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:53PM -0700, Nick Desaulniers wrote:
> Avoids an error from the assembler for CONFIG_THUMB2 kernels:
> 
> clang-15: error: hardware TLS register is not supported for the thumbv4t
> sub-architecture
> 
> This flag only makes sense to pass to the compiler, not the assembler.
> 
> Perhaps CFLAGS_ABI can be renamed to CPPFLAGS_ABI to reflect that they
> will be passed to both the compiler and assembler for sources that
> require pre-processing.
> 
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  arch/arm/Makefile | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 8dd943b50b7d..ee888070b2ff 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -111,7 +111,7 @@ CFLAGS_ABI	+= -meabi gnu
>  endif
>  
>  ifeq ($(CONFIG_CURRENT_POINTER_IN_TPIDRURO),y)
> -CFLAGS_ABI	+= -mtp=cp15
> +KBUILD_CFLAGS	+= -mtp=cp15
>  endif
>  
>  # Accept old syntax despite ".syntax unified"
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 4/4] ARM: pass -march= only to compiler
  2022-10-14 20:13   ` Nick Desaulniers
@ 2022-10-14 21:21     ` Nathan Chancellor
  -1 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:21 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:54PM -0700, Nick Desaulniers wrote:
> When both -march= and -Wa,-march= are specified for assembler or
> assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
> value but Clang will warn that -march= is unused.
> 
> warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
> 
> This is the top group of warnings we observe when using clang to
> assemble the kernel via `ARCH=arm make LLVM=1`.
> 
> Split the arch-y make variable into two, so that -march= flags only get
> passed to the compiler, not the assembler. -D flags are added to
> KBUILD_CPPFLAGS which is used for both C and assembler-with-cpp sources.
> 
> Clang is trying to warn that it doesn't support different values for
> -march= and -Wa,-march= (like GCC does, but the kernel doesn't need this)
> though the value of the preprocessor define __thumb2__ is based on
> -march=. Make sure to re-set __thumb2__ via -D flag for assembler
> sources now that we're no longer passing -march= to the assembler. Set
> it to a different value than the preprocessor would for -march= in case
> -march= gets accidentally re-added to KBUILD_AFLAGS in the future.
> Thanks to Ard and Nathan for this suggestion.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/1315
> Link: https://github.com/ClangBuiltLinux/linux/issues/1587
> Link: https://github.com/llvm/llvm-project/issues/55656
> Suggested-by: Ard Biesheuvel <ardb@kernel.org>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

This passed through my build matrix on top of commit dca45efbe3c8
("Merge tag 'sound-fix-6.1-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound") and I saw no
additional warnings/errors:

Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
> Changes v3 -> v4:
> * Add -D__thumb2__=2 to KBUILD_AFLAGS as per in-person discussion with
>   Ard and Nathan, and their SB tags.
> * Reword commit message.
> 
>  arch/arm/Makefile | 36 +++++++++++++++++++++++++-----------
>  1 file changed, 25 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index ee888070b2ff..b58998749ead 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -60,21 +60,34 @@ endif
>  KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
>  
>  # This selects which instruction set is used.
> +arch-$(CONFIG_CPU_32v7M)	:=-march=armv7-m
> +arch-$(CONFIG_CPU_32v7)		:=-march=armv7-a
> +arch-$(CONFIG_CPU_32v6)		:=-march=armv6
> +# Only override the compiler option if ARMv6. The ARMv6K extensions are
> +# always available in ARMv7
> +ifeq ($(CONFIG_CPU_32v6),y)
> +arch-$(CONFIG_CPU_32v6K)	:=-march=armv6k
> +endif
> +arch-$(CONFIG_CPU_32v5)		:=-march=armv5te
> +arch-$(CONFIG_CPU_32v4T)	:=-march=armv4t
> +arch-$(CONFIG_CPU_32v4)		:=-march=armv4
> +arch-$(CONFIG_CPU_32v3)		:=-march=armv3m
> +
>  # Note that GCC does not numerically define an architecture version
>  # macro, but instead defines a whole series of macros which makes
>  # testing for a specific architecture or later rather impossible.
> -arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
> -arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
> -arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
> -# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
> +cpp-$(CONFIG_CPU_32v7M)		:=-D__LINUX_ARM_ARCH__=7
> +cpp-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7
> +cpp-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6
> +# Only override the compiler option if ARMv6. The ARMv6K extensions are
>  # always available in ARMv7
>  ifeq ($(CONFIG_CPU_32v6),y)
> -arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
> +cpp-$(CONFIG_CPU_32v6K)		:=-D__LINUX_ARM_ARCH__=6
>  endif
> -arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
> -arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
> -arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
> -arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
> +cpp-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5
> +cpp-$(CONFIG_CPU_32v4T)		:=-D__LINUX_ARM_ARCH__=4
> +cpp-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4
> +cpp-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3
>  
>  # This selects how we optimise for the processor.
>  tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
> @@ -119,15 +132,16 @@ AFLAGS_NOWARN	:=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
>  
>  ifeq ($(CONFIG_THUMB2_KERNEL),y)
>  CFLAGS_ISA	:=-mthumb -Wa,-mimplicit-it=always $(AFLAGS_NOWARN)
> -AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb
> +AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb -D__thumb2__=2
>  else
>  CFLAGS_ISA	:=$(call cc-option,-marm,) $(AFLAGS_NOWARN)
>  AFLAGS_ISA	:=$(CFLAGS_ISA)
>  endif
>  
>  # Need -Uarm for gcc < 3.x
> +KBUILD_CPPFLAGS	+=$(cpp-y)
>  KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
> -KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
> +KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) -Wa,$(arch-y) $(tune-y) -include asm/unified.h -msoft-float
>  
>  CHECKFLAGS	+= -D__arm__
>  
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 4/4] ARM: pass -march= only to compiler
@ 2022-10-14 21:21     ` Nathan Chancellor
  0 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-10-14 21:21 UTC (permalink / raw)
  To: Nick Desaulniers
  Cc: Russell King, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Fri, Oct 14, 2022 at 01:13:54PM -0700, Nick Desaulniers wrote:
> When both -march= and -Wa,-march= are specified for assembler or
> assembler-with-cpp sources, GCC and Clang will prefer the -Wa,-march=
> value but Clang will warn that -march= is unused.
> 
> warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
> 
> This is the top group of warnings we observe when using clang to
> assemble the kernel via `ARCH=arm make LLVM=1`.
> 
> Split the arch-y make variable into two, so that -march= flags only get
> passed to the compiler, not the assembler. -D flags are added to
> KBUILD_CPPFLAGS which is used for both C and assembler-with-cpp sources.
> 
> Clang is trying to warn that it doesn't support different values for
> -march= and -Wa,-march= (like GCC does, but the kernel doesn't need this)
> though the value of the preprocessor define __thumb2__ is based on
> -march=. Make sure to re-set __thumb2__ via -D flag for assembler
> sources now that we're no longer passing -march= to the assembler. Set
> it to a different value than the preprocessor would for -march= in case
> -march= gets accidentally re-added to KBUILD_AFLAGS in the future.
> Thanks to Ard and Nathan for this suggestion.
> 
> Link: https://github.com/ClangBuiltLinux/linux/issues/1315
> Link: https://github.com/ClangBuiltLinux/linux/issues/1587
> Link: https://github.com/llvm/llvm-project/issues/55656
> Suggested-by: Ard Biesheuvel <ardb@kernel.org>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>

This passed through my build matrix on top of commit dca45efbe3c8
("Merge tag 'sound-fix-6.1-rc1' of
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound") and I saw no
additional warnings/errors:

Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>

> ---
> Changes v3 -> v4:
> * Add -D__thumb2__=2 to KBUILD_AFLAGS as per in-person discussion with
>   Ard and Nathan, and their SB tags.
> * Reword commit message.
> 
>  arch/arm/Makefile | 36 +++++++++++++++++++++++++-----------
>  1 file changed, 25 insertions(+), 11 deletions(-)
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index ee888070b2ff..b58998749ead 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -60,21 +60,34 @@ endif
>  KBUILD_CFLAGS	+= $(call cc-option,-fno-ipa-sra)
>  
>  # This selects which instruction set is used.
> +arch-$(CONFIG_CPU_32v7M)	:=-march=armv7-m
> +arch-$(CONFIG_CPU_32v7)		:=-march=armv7-a
> +arch-$(CONFIG_CPU_32v6)		:=-march=armv6
> +# Only override the compiler option if ARMv6. The ARMv6K extensions are
> +# always available in ARMv7
> +ifeq ($(CONFIG_CPU_32v6),y)
> +arch-$(CONFIG_CPU_32v6K)	:=-march=armv6k
> +endif
> +arch-$(CONFIG_CPU_32v5)		:=-march=armv5te
> +arch-$(CONFIG_CPU_32v4T)	:=-march=armv4t
> +arch-$(CONFIG_CPU_32v4)		:=-march=armv4
> +arch-$(CONFIG_CPU_32v3)		:=-march=armv3m
> +
>  # Note that GCC does not numerically define an architecture version
>  # macro, but instead defines a whole series of macros which makes
>  # testing for a specific architecture or later rather impossible.
> -arch-$(CONFIG_CPU_32v7M)	:=-D__LINUX_ARM_ARCH__=7 -march=armv7-m
> -arch-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7 -march=armv7-a
> -arch-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6 -march=armv6
> -# Only override the compiler opt:ion if ARMv6. The ARMv6K extensions are
> +cpp-$(CONFIG_CPU_32v7M)		:=-D__LINUX_ARM_ARCH__=7
> +cpp-$(CONFIG_CPU_32v7)		:=-D__LINUX_ARM_ARCH__=7
> +cpp-$(CONFIG_CPU_32v6)		:=-D__LINUX_ARM_ARCH__=6
> +# Only override the compiler option if ARMv6. The ARMv6K extensions are
>  # always available in ARMv7
>  ifeq ($(CONFIG_CPU_32v6),y)
> -arch-$(CONFIG_CPU_32v6K)	:=-D__LINUX_ARM_ARCH__=6 -march=armv6k
> +cpp-$(CONFIG_CPU_32v6K)		:=-D__LINUX_ARM_ARCH__=6
>  endif
> -arch-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5 -march=armv5te
> -arch-$(CONFIG_CPU_32v4T)	:=-D__LINUX_ARM_ARCH__=4 -march=armv4t
> -arch-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4 -march=armv4
> -arch-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3 -march=armv3m
> +cpp-$(CONFIG_CPU_32v5)		:=-D__LINUX_ARM_ARCH__=5
> +cpp-$(CONFIG_CPU_32v4T)		:=-D__LINUX_ARM_ARCH__=4
> +cpp-$(CONFIG_CPU_32v4)		:=-D__LINUX_ARM_ARCH__=4
> +cpp-$(CONFIG_CPU_32v3)		:=-D__LINUX_ARM_ARCH__=3
>  
>  # This selects how we optimise for the processor.
>  tune-$(CONFIG_CPU_ARM7TDMI)	:=-mtune=arm7tdmi
> @@ -119,15 +132,16 @@ AFLAGS_NOWARN	:=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
>  
>  ifeq ($(CONFIG_THUMB2_KERNEL),y)
>  CFLAGS_ISA	:=-mthumb -Wa,-mimplicit-it=always $(AFLAGS_NOWARN)
> -AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb
> +AFLAGS_ISA	:=$(CFLAGS_ISA) -Wa$(comma)-mthumb -D__thumb2__=2
>  else
>  CFLAGS_ISA	:=$(call cc-option,-marm,) $(AFLAGS_NOWARN)
>  AFLAGS_ISA	:=$(CFLAGS_ISA)
>  endif
>  
>  # Need -Uarm for gcc < 3.x
> +KBUILD_CPPFLAGS	+=$(cpp-y)
>  KBUILD_CFLAGS	+=$(CFLAGS_ABI) $(CFLAGS_ISA) $(arch-y) $(tune-y) $(call cc-option,-mshort-load-bytes,$(call cc-option,-malignment-traps,)) -msoft-float -Uarm
> -KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) $(arch-y) $(tune-y) -include asm/unified.h -msoft-float
> +KBUILD_AFLAGS	+=$(CFLAGS_ABI) $(AFLAGS_ISA) -Wa,$(arch-y) $(tune-y) -include asm/unified.h -msoft-float
>  
>  CHECKFLAGS	+= -D__arm__
>  
> -- 
> 2.38.0.413.g74048e4d9e-goog
> 

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
  2022-10-14 20:13   ` Nick Desaulniers
@ 2022-11-08 18:30     ` Nathan Chancellor
  -1 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-11-08 18:30 UTC (permalink / raw)
  To: Russell King, Nick Desaulniers
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm

Hi Russell,

On Fri, Oct 14, 2022 at 01:13:52PM -0700, Nick Desaulniers wrote:
> Similar to commit a6c30873ee4a ("ARM: 8989/1: use .fpu assembler
> directives instead of assembler arguments").
> 
> GCC and GNU binutils support setting the "sub arch" via -march=,
> -Wa,-march, target function attribute, and .arch assembler directive.
> 
> Clang was missing support for -Wa,-march=, but this was implemented in
> clang-13.
> 
> The behavior of both GCC and Clang is to
> prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
> sources, but Clang will warn about the -march= being unused.
> 
> clang: warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
> 
> Since most assembler is non-conditionally assembled with one sub arch
> (modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
> based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
> conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
> .arch assembler directive.
> 
> Add a few more instances found in compile testing as found by Arnd and
> Nathan.
> 
> Link: https://github.com/llvm/llvm-project/commit/1d51c699b9e2ebc5bcfdbe85c74cc871426333d4
> Link: https://bugs.llvm.org/show_bug.cgi?id=48894
> Link: https://github.com/ClangBuiltLinux/linux/issues/1195
> Link: https://github.com/ClangBuiltLinux/linux/issues/1315
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> Changes v3 -> v4:
> * Add .arch armv7-a to arch/arm/mach-tegra/sleep.S as per Nathan.
>   https://github.com/ClangBuiltLinux/linux/issues/1315#issuecomment-1255646893
> * Add Nathan's SB tag.

I noticed that this series appears to be partially applied in
next-20221108:

59247fe730db ARM: 9265/1: pass -march= only to compiler
bc21212c5564 ARM: 9264/1: only use -mtp=cp15 for the compiler
5aa4860eb50f ARM: 9262/1: remove lazy evaluation in Makefile

This patch (submitted as 9263/1) is needed by 9265/1; without it, builds
are going to break:

https://builds.tuxbuild.com/2HGSpQMAKxJuaMAz2ZZc1UgUvvu/build.log

Was there a problem with applying this patch or just an oversight? It
would be great to get this whole series applied so that we can turn
-Wunused-command-line-argument into a hard error.

Cheers,
Nathan

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
@ 2022-11-08 18:30     ` Nathan Chancellor
  0 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-11-08 18:30 UTC (permalink / raw)
  To: Russell King, Nick Desaulniers
  Cc: Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada, Linus Walleij,
	linux-arm-kernel, linux-kernel, llvm

Hi Russell,

On Fri, Oct 14, 2022 at 01:13:52PM -0700, Nick Desaulniers wrote:
> Similar to commit a6c30873ee4a ("ARM: 8989/1: use .fpu assembler
> directives instead of assembler arguments").
> 
> GCC and GNU binutils support setting the "sub arch" via -march=,
> -Wa,-march, target function attribute, and .arch assembler directive.
> 
> Clang was missing support for -Wa,-march=, but this was implemented in
> clang-13.
> 
> The behavior of both GCC and Clang is to
> prefer -Wa,-march= over -march= for assembler and assembler-with-cpp
> sources, but Clang will warn about the -march= being unused.
> 
> clang: warning: argument unused during compilation: '-march=armv6k'
> [-Wunused-command-line-argument]
> 
> Since most assembler is non-conditionally assembled with one sub arch
> (modulo arch/arm/delay-loop.S which conditionally is assembled as armv4
> based on CONFIG_ARCH_RPC, and arch/arm/mach-at91/pm-suspend.S which is
> conditionally assembled as armv7-a based on CONFIG_CPU_V7), prefer the
> .arch assembler directive.
> 
> Add a few more instances found in compile testing as found by Arnd and
> Nathan.
> 
> Link: https://github.com/llvm/llvm-project/commit/1d51c699b9e2ebc5bcfdbe85c74cc871426333d4
> Link: https://bugs.llvm.org/show_bug.cgi?id=48894
> Link: https://github.com/ClangBuiltLinux/linux/issues/1195
> Link: https://github.com/ClangBuiltLinux/linux/issues/1315
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Suggested-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> Changes v3 -> v4:
> * Add .arch armv7-a to arch/arm/mach-tegra/sleep.S as per Nathan.
>   https://github.com/ClangBuiltLinux/linux/issues/1315#issuecomment-1255646893
> * Add Nathan's SB tag.

I noticed that this series appears to be partially applied in
next-20221108:

59247fe730db ARM: 9265/1: pass -march= only to compiler
bc21212c5564 ARM: 9264/1: only use -mtp=cp15 for the compiler
5aa4860eb50f ARM: 9262/1: remove lazy evaluation in Makefile

This patch (submitted as 9263/1) is needed by 9265/1; without it, builds
are going to break:

https://builds.tuxbuild.com/2HGSpQMAKxJuaMAz2ZZc1UgUvvu/build.log

Was there a problem with applying this patch or just an oversight? It
would be great to get this whole series applied so that we can turn
-Wunused-command-line-argument into a hard error.

Cheers,
Nathan

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
  2022-11-08 18:30     ` Nathan Chancellor
@ 2022-11-08 18:37       ` Russell King (Oracle)
  -1 siblings, 0 replies; 26+ messages in thread
From: Russell King (Oracle) @ 2022-11-08 18:37 UTC (permalink / raw)
  To: Nathan Chancellor
  Cc: Nick Desaulniers, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Tue, Nov 08, 2022 at 11:30:39AM -0700, Nathan Chancellor wrote:
> I noticed that this series appears to be partially applied in
> next-20221108:
> 
> 59247fe730db ARM: 9265/1: pass -march= only to compiler
> bc21212c5564 ARM: 9264/1: only use -mtp=cp15 for the compiler
> 5aa4860eb50f ARM: 9262/1: remove lazy evaluation in Makefile
> 
> This patch (submitted as 9263/1) is needed by 9265/1; without it, builds
> are going to break:
> 
> https://builds.tuxbuild.com/2HGSpQMAKxJuaMAz2ZZc1UgUvvu/build.log
> 
> Was there a problem with applying this patch or just an oversight? It
> would be great to get this whole series applied so that we can turn
> -Wunused-command-line-argument into a hard error.

Patching 9263/1...
git apply --whitespace=fix -p1 --index --check > /tmp/pdb.726086 2>&1
exited with non-zero status: 256
error: patch failed: arch/arm/mach-mvebu/Makefile:1
error: arch/arm/mach-mvebu/Makefile: patch does not apply

The problem appears to be:

84fc86360623 ARM: make ARCH_MULTIPLATFORM user-visible

which is not in my misc branch. I've applied your patch using GNU
patch with a fuzz of 2, and the resulting diff looks sensible. I'll
push it out later this evening.

Thanks for the heads-up.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
@ 2022-11-08 18:37       ` Russell King (Oracle)
  0 siblings, 0 replies; 26+ messages in thread
From: Russell King (Oracle) @ 2022-11-08 18:37 UTC (permalink / raw)
  To: Nathan Chancellor
  Cc: Nick Desaulniers, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Tue, Nov 08, 2022 at 11:30:39AM -0700, Nathan Chancellor wrote:
> I noticed that this series appears to be partially applied in
> next-20221108:
> 
> 59247fe730db ARM: 9265/1: pass -march= only to compiler
> bc21212c5564 ARM: 9264/1: only use -mtp=cp15 for the compiler
> 5aa4860eb50f ARM: 9262/1: remove lazy evaluation in Makefile
> 
> This patch (submitted as 9263/1) is needed by 9265/1; without it, builds
> are going to break:
> 
> https://builds.tuxbuild.com/2HGSpQMAKxJuaMAz2ZZc1UgUvvu/build.log
> 
> Was there a problem with applying this patch or just an oversight? It
> would be great to get this whole series applied so that we can turn
> -Wunused-command-line-argument into a hard error.

Patching 9263/1...
git apply --whitespace=fix -p1 --index --check > /tmp/pdb.726086 2>&1
exited with non-zero status: 256
error: patch failed: arch/arm/mach-mvebu/Makefile:1
error: arch/arm/mach-mvebu/Makefile: patch does not apply

The problem appears to be:

84fc86360623 ARM: make ARCH_MULTIPLATFORM user-visible

which is not in my misc branch. I've applied your patch using GNU
patch with a fuzz of 2, and the resulting diff looks sensible. I'll
push it out later this evening.

Thanks for the heads-up.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
  2022-11-08 18:37       ` Russell King (Oracle)
@ 2022-11-08 18:40         ` Nathan Chancellor
  -1 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-11-08 18:40 UTC (permalink / raw)
  To: Russell King (Oracle)
  Cc: Nick Desaulniers, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Tue, Nov 08, 2022 at 06:37:02PM +0000, Russell King (Oracle) wrote:
> On Tue, Nov 08, 2022 at 11:30:39AM -0700, Nathan Chancellor wrote:
> > I noticed that this series appears to be partially applied in
> > next-20221108:
> > 
> > 59247fe730db ARM: 9265/1: pass -march= only to compiler
> > bc21212c5564 ARM: 9264/1: only use -mtp=cp15 for the compiler
> > 5aa4860eb50f ARM: 9262/1: remove lazy evaluation in Makefile
> > 
> > This patch (submitted as 9263/1) is needed by 9265/1; without it, builds
> > are going to break:
> > 
> > https://builds.tuxbuild.com/2HGSpQMAKxJuaMAz2ZZc1UgUvvu/build.log
> > 
> > Was there a problem with applying this patch or just an oversight? It
> > would be great to get this whole series applied so that we can turn
> > -Wunused-command-line-argument into a hard error.
> 
> Patching 9263/1...
> git apply --whitespace=fix -p1 --index --check > /tmp/pdb.726086 2>&1
> exited with non-zero status: 256
> error: patch failed: arch/arm/mach-mvebu/Makefile:1
> error: arch/arm/mach-mvebu/Makefile: patch does not apply
> 
> The problem appears to be:
> 
> 84fc86360623 ARM: make ARCH_MULTIPLATFORM user-visible
> 
> which is not in my misc branch. I've applied your patch using GNU
> patch with a fuzz of 2, and the resulting diff looks sensible. I'll
> push it out later this evening.
> 
> Thanks for the heads-up.

Perfect, thanks a lot for the quick response! I figured it was something
like that. I will keep an eye out for any additional breakage and follow
up with patches or additional emails as necessary.

Cheers,
Nathan

^ permalink raw reply	[flat|nested] 26+ messages in thread
* Re: [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags
@ 2022-11-08 18:40         ` Nathan Chancellor
  0 siblings, 0 replies; 26+ messages in thread
From: Nathan Chancellor @ 2022-11-08 18:40 UTC (permalink / raw)
  To: Russell King (Oracle)
  Cc: Nick Desaulniers, Arnd Bergmann, Ard Biesheuvel, Masahiro Yamada,
	Linus Walleij, linux-arm-kernel, linux-kernel, llvm

On Tue, Nov 08, 2022 at 06:37:02PM +0000, Russell King (Oracle) wrote:
> On Tue, Nov 08, 2022 at 11:30:39AM -0700, Nathan Chancellor wrote:
> > I noticed that this series appears to be partially applied in
> > next-20221108:
> > 
> > 59247fe730db ARM: 9265/1: pass -march= only to compiler
> > bc21212c5564 ARM: 9264/1: only use -mtp=cp15 for the compiler
> > 5aa4860eb50f ARM: 9262/1: remove lazy evaluation in Makefile
> > 
> > This patch (submitted as 9263/1) is needed by 9265/1; without it, builds
> > are going to break:
> > 
> > https://builds.tuxbuild.com/2HGSpQMAKxJuaMAz2ZZc1UgUvvu/build.log
> > 
> > Was there a problem with applying this patch or just an oversight? It
> > would be great to get this whole series applied so that we can turn
> > -Wunused-command-line-argument into a hard error.
> 
> Patching 9263/1...
> git apply --whitespace=fix -p1 --index --check > /tmp/pdb.726086 2>&1
> exited with non-zero status: 256
> error: patch failed: arch/arm/mach-mvebu/Makefile:1
> error: arch/arm/mach-mvebu/Makefile: patch does not apply
> 
> The problem appears to be:
> 
> 84fc86360623 ARM: make ARCH_MULTIPLATFORM user-visible
> 
> which is not in my misc branch. I've applied your patch using GNU
> patch with a fuzz of 2, and the resulting diff looks sensible. I'll
> push it out later this evening.
> 
> Thanks for the heads-up.

Perfect, thanks a lot for the quick response! I figured it was something
like that. I will keep an eye out for any additional breakage and follow
up with patches or additional emails as necessary.

Cheers,
Nathan

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 26+ messages in thread
end of thread, other threads:[~2022-11-08 18:41 UTC | newest]

Thread overview: 26+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-10-14 20:13 [PATCH v4 0/4] pass -march= only to compiler Nick Desaulniers
2022-10-14 20:13 ` Nick Desaulniers
2022-10-14 20:13 ` [PATCH v4 1/4] ARM: remove lazy evaluation in Makefile Nick Desaulniers
2022-10-14 20:13   ` Nick Desaulniers
2022-10-14 21:18   ` Nathan Chancellor
2022-10-14 21:18     ` Nathan Chancellor
2022-10-14 20:13 ` [PATCH v4 2/4] ARM: use .arch directives instead of assembler command line flags Nick Desaulniers
2022-10-14 20:13   ` Nick Desaulniers
2022-10-14 21:19   ` Nathan Chancellor
2022-10-14 21:19     ` Nathan Chancellor
2022-11-08 18:30   ` Nathan Chancellor
2022-11-08 18:30     ` Nathan Chancellor
2022-11-08 18:37     ` Russell King (Oracle)
2022-11-08 18:37       ` Russell King (Oracle)
2022-11-08 18:40       ` Nathan Chancellor
2022-11-08 18:40         ` Nathan Chancellor
2022-10-14 20:13 ` [PATCH v4 3/4] ARM: only use -mtp=cp15 for the compiler Nick Desaulniers
2022-10-14 20:13   ` Nick Desaulniers
2022-10-14 21:20   ` Nathan Chancellor
2022-10-14 21:20     ` Nathan Chancellor
2022-10-14 20:13 ` [PATCH v4 4/4] ARM: pass -march= only to compiler Nick Desaulniers
2022-10-14 20:13   ` Nick Desaulniers
2022-10-14 21:21   ` Nathan Chancellor
2022-10-14 21:21     ` Nathan Chancellor
2022-10-14 20:16 ` [PATCH v4 0/4] " Nick Desaulniers
2022-10-14 20:16   ` Nick Desaulniers

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