[ 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@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: James Morse james.morse@arm.com Cc: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/20240508081400.235362-2-mark.rutland@arm.com Signed-off-by: Will Deacon will@kernel.org [ Mark: fix conflict ] Signed-off-by: Mark Rutland mark.rutland@arm.com --- arch/arm64/include/asm/barrier.h | 4 ++++ 1 file changed, 4 insertions(+)
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 { \