aboutsummaryrefslogtreecommitdiff
path: root/arch/arm64/include/asm/assembler.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm64/include/asm/assembler.h')
-rw-r--r--arch/arm64/include/asm/assembler.h24
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index e8bd0af0141c..046c38ee2841 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -850,4 +850,28 @@ alternative_endif
#endif /* GNU_PROPERTY_AARCH64_FEATURE_1_DEFAULT */
+ .macro __mitigate_spectre_bhb_loop tmp
+#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
+ mov \tmp, #32
+.Lspectre_bhb_loop\@:
+ b . + 4
+ subs \tmp, \tmp, #1
+ b.ne .Lspectre_bhb_loop\@
+ sb
+#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
+ .endm
+
+ /* Save/restores x0-x3 to the stack */
+ .macro __mitigate_spectre_bhb_fw
+#ifdef CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY
+ stp x0, x1, [sp, #-16]!
+ stp x2, x3, [sp, #-16]!
+ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_3
+alternative_cb smccc_patch_fw_mitigation_conduit
+ nop // Patched to SMC/HVC #0
+alternative_cb_end
+ ldp x2, x3, [sp], #16
+ ldp x0, x1, [sp], #16
+#endif /* CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY */
+ .endm
#endif /* __ASM_ASSEMBLER_H */