[PATCH 4/8] arm64: insn: Add helpers for adrp offsets

From: Suzuki K Poulose
Date: Thu Aug 18 2016 - 09:20:25 EST


Adds helpers for decoding/encoding the PC relative addresses for adrp.
This will be used for handling dynamic patching of 'adrp' instructions
in alternative code patching.

Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
---
arch/arm64/include/asm/insn.h | 4 ++++
arch/arm64/kernel/insn.c | 13 +++++++++++++
2 files changed, 17 insertions(+)

diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 1dbaa90..dffb0364 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -247,6 +247,7 @@ static __always_inline u32 aarch64_insn_get_##abbr##_value(void) \
{ return (val); }

__AARCH64_INSN_FUNCS(adr_adrp, 0x1F000000, 0x10000000)
+__AARCH64_INSN_FUNCS(adrp, 0x9F000000, 0x90000000)
__AARCH64_INSN_FUNCS(prfm_lit, 0xFF000000, 0xD8000000)
__AARCH64_INSN_FUNCS(str_reg, 0x3FE0EC00, 0x38206800)
__AARCH64_INSN_FUNCS(ldr_reg, 0x3FE0EC00, 0x38606800)
@@ -398,6 +399,9 @@ 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);

+s32 aarch64_insn_adrp_get_offset(u32 insn);
+u32 aarch64_insn_adrp_set_offset(u32 insn, s32 offset);
+
bool aarch32_insn_is_wide(u32 insn);

#define A32_RN_OFFSET 16
diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 63f9432..f022af4 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -1202,6 +1202,19 @@ u32 aarch64_set_branch_offset(u32 insn, s32 offset)
BUG();
}

+s32 aarch64_insn_adrp_get_offset(u32 insn)
+{
+ BUG_ON(!aarch64_insn_is_adrp(insn));
+ return aarch64_insn_decode_immediate(AARCH64_INSN_IMM_ADR, insn) << 12;
+}
+
+u32 aarch64_insn_adrp_set_offset(u32 insn, s32 offset)
+{
+ BUG_ON(!aarch64_insn_is_adrp(insn));
+ return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_ADR, insn,
+ offset >> 12);
+}
+
/*
* Extract the Op/CR data from a msr/mrs instruction.
*/
--
2.7.4