This is a note to let you know that I've just added the patch titled
arm64: barrier: Restore spec_bar() macro
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-barrier-restore-spec_bar-macro.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b4b37c4707232acab500fee74e60c3539f030954
Author: Mark Rutland <mark.rutland@xxxxxxx>
Date: Fri Aug 9 11:09:23 2024 +0100
arm64: barrier: Restore spec_bar() macro
[ Upstream commit ebfc726eae3f31bdb5fae1bbd74ef235d71046ca ]
Upcoming errata workarounds will need to use SB from C code. Restore the
spec_bar() macro so that we can use SB.
This is effectively a revert of commit:
4f30ba1cce36d413 ("arm64: barrier: Remove spec_bar() macro")
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: James Morse <james.morse@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240508081400.235362-2-mark.rutland@xxxxxxx
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
[ Mark: fix conflict ]
Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 1c5a005984582..6e3f4eea1f34d 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -26,6 +26,10 @@
#define __tsb_csync() asm volatile("hint #18" : : : "memory")
#define csdb() asm volatile("hint #20" : : : "memory")
+#define spec_bar() asm volatile(ALTERNATIVE("dsb nsh\nisb\n", \
+ SB_BARRIER_INSN"nop\n", \
+ ARM64_HAS_SB))
+
#ifdef CONFIG_ARM64_PSEUDO_NMI
#define pmr_sync() \
do { \
