error: invalid instruction arch/arm/mm/tlb-v7.S

[nickdesaulniers]

building allyesconfig with LLVM_IAS=1:

$ ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- make LLVM=1 LLVM_IAS=1 -j71 arch/arm/mm/tlb-v7.o
...
clang-12: warning: argument unused during compilation: '-march=armv6k' [-Wunused-command-line-argument]
clang-12: warning: argument unused during compilation: '-Wa,-march=armv7-a' [-Wunused-command-line-argument]
arch/arm/mm/tlb-v7.S:35:2: error: invalid instruction
 dsb ish
 ^
arch/arm/mm/tlb-v7.S:56:2: error: invalid instruction
 dsb ish
 ^
arch/arm/mm/tlb-v7.S:69:2: error: invalid instruction
 dsb ish
 ^
arch/arm/mm/tlb-v7.S:84:2: error: invalid instruction
 dsb ish
 ^
arch/arm/mm/tlb-v7.S:85:2: error: instruction requires: data-barriers
 isb
 ^

similar to 7548bf8

diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile
index 3510503bc5e6..6e9b54714500 100644
--- a/arch/arm/mm/Makefile
+++ b/arch/arm/mm/Makefile
@@ -73,7 +73,6 @@ 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
diff --git a/arch/arm/mm/tlb-v7.S b/arch/arm/mm/tlb-v7.S
index 1bb28d7db567..2643e2f51b6a 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)
  *

fixes the error. cc @jcai19

[nickdesaulniers]

eh, this is pretty common due to commit aff7b4f ("ARM: Ensure ARMv6/7 mm files are built using appropriate assembler options")

[nickdesaulniers]

tempted to mark this a dup of #957.

[nickdesaulniers]

Note that arch/arm64/Makefile has code like:

 91 ifeq ($(CONFIG_AS_HAS_PAC), y)                                                                                                                                                                                                         
 92 asm-arch := armv8.3-a                                                                                                                                                                                                                  
 93 endif                                                                                                                                                                                                                                  
 94 endif                                                                                                                                                                                                                                  
 95                                                                                                                                                                                                                                        
 96 KBUILD_CFLAGS += $(branch-prot-flags-y)                                                                                                                                                                                                
 97                                                                                                                                                                                                                                        
 98 ifeq ($(CONFIG_AS_HAS_ARMV8_4), y)                                                                                                                                                                                                     
 99 # make sure to pass the newest target architecture to -march.                                                                                                                                                                          
100 asm-arch := armv8.4-a                                                                                                                                                                                                                  
101 endif                                                                                                                                                                                                                                  
102                                                                                                                                                                                                                                        
103 ifdef asm-arch                                                                                                                                                                                                                         
104 KBUILD_CFLAGS += -Wa,-march=$(asm-arch) \                                                                                                                                                                                              
105        -DARM64_ASM_ARCH='"$(asm-arch)"'                                                                                                                                                                                                
106 endif 

and it seems like the Kconfig checks are working, so is it the case that we support -Wa,-march= for aarch64 but not 32b arm?

[nathanchance]

Isn't the issue that -Wa,... is not used with the integrated assembler? That block was added due to the outcome of #1106.

[nickdesaulniers]

#1106 (comment)
#1106 (comment)

[nickdesaulniers]

https://llvm.org/pr48894

[nickdesaulniers]

ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- make LLVM=1 LLVM_IAS=1 -j72 defconfig enabled both

CONFIG_CPU_32v6K=y                                                                                                                                                         
CONFIG_CPU_32v7=y    

cc @arndb should those be mutually exclusive?