ARM: 9263/1: use .arch directives instead of assembler command line flags

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>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

5 files changed, 8 insertions, 2 deletions

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