arm64: introduce interfaces to hotpatch kernel and module code

Introduce three interfaces to patch kernel and module code:
aarch64_insn_patch_text_nosync():
	patch code without synchronization, it's caller's responsibility
	to synchronize all CPUs if needed.
aarch64_insn_patch_text_sync():
	patch code and always synchronize with stop_machine()
aarch64_insn_patch_text():
	patch code and synchronize with stop_machine() if needed

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 1bdc44c27456..bf8085fdc140 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -18,6 +18,9 @@
 #define	__ASM_INSN_H
 #include <linux/types.h>
 
+/* A64 instructions are always 32 bits. */
+#define	AARCH64_INSN_SIZE		4
+
 /*
  * ARM Architecture Reference Manual for ARMv8 Profile-A, Issue A.a
  * Section C3.1 "A64 instruction index by encoding":
@@ -70,8 +73,13 @@ __AARCH64_INSN_FUNCS(hint,	0xFFFFF01F, 0xD503201F)
 
 bool aarch64_insn_is_nop(u32 insn);
 
+int aarch64_insn_read(void *addr, u32 *insnp);
+int aarch64_insn_write(void *addr, u32 insn);
 enum aarch64_insn_encoding_class aarch64_get_insn_class(u32 insn);
-
 bool aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn);
 
+int aarch64_insn_patch_text_nosync(void *addr, u32 insn);
+int aarch64_insn_patch_text_sync(void *addrs[], u32 insns[], int cnt);
+int aarch64_insn_patch_text(void *addrs[], u32 insns[], int cnt);
+
 #endif	/* __ASM_INSN_H */