Commit 1a2c73f4 authored by Jiaxun Yang's avatar Jiaxun Yang Committed by Thomas Bogendoerfer
Browse files

MIPS: Workaround clang inline compat branch issue 

Clang is unable to handle the situation that a chunk of inline
assembly ends with a compat branch instruction and then compiler
generates another control transfer instruction immediately after
this compat branch. The later instruction will end up in forbidden
slot and cause exception.

Workaround by add a option to control the use of compact branch.
Currently it's selected by CC_IS_CLANG and hopefully we can change
it to a version check in future if clang manages to fix it.

Fix boot on boston board.

Link: https://github.com/llvm/llvm-project/issues/61045


Signed-off-by: default avatarJiaxun Yang <jiaxun.yang@flygoat.com>
Acked-by: default avatarNathan Chancellor <nathan@kernel.org>
Acked-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
parent 70f864d1

arch/mips/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -3200,6 +3200,10 @@ config CC_HAS_MNO_BRANCH_LIKELY 
	def_bool y

	depends on $(cc-option,-mno-branch-likely)



# https://github.com/llvm/llvm-project/issues/61045

config CC_HAS_BROKEN_INLINE_COMPAT_BRANCH

	def_bool y if CC_IS_CLANG



menu "Power management options"



config ARCH_HIBERNATION_POSSIBLE

arch/mips/include/asm/asm.h

+1 −1
Original line number Diff line number Diff line
@@ -336,7 +336,7 @@ symbol = value 
 */

#ifdef CONFIG_WAR_R10000_LLSC

# define SC_BEQZ	beqzl

#elif MIPS_ISA_REV >= 6

#elif !defined(CONFIG_CC_HAS_BROKEN_INLINE_COMPAT_BRANCH) && MIPS_ISA_REV >= 6

# define SC_BEQZ	beqzc

#else

# define SC_BEQZ	beqz