[PATCHv2 09/14] arm64: introduce aarch64_insn_gen_add_sub_shifted_reg()

From: Zi Shen Lim
Date: Wed Aug 27 2014 - 00:16:03 EST


Introduce function to generate add/subtract (shifted register)
instructions.

Signed-off-by: Zi Shen Lim <zlim.lnx@xxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
---
arch/arm64/include/asm/insn.h | 11 ++++++++++
arch/arm64/kernel/insn.c | 49 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 60 insertions(+)

diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 49dec28..c0a765d 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -67,6 +67,7 @@ enum aarch64_insn_imm_type {
AARCH64_INSN_IMM_12,
AARCH64_INSN_IMM_9,
AARCH64_INSN_IMM_7,
+ AARCH64_INSN_IMM_6,
AARCH64_INSN_IMM_S,
AARCH64_INSN_IMM_R,
AARCH64_INSN_IMM_MAX
@@ -206,6 +207,10 @@ __AARCH64_INSN_FUNCS(bfm, 0x7F800000, 0x33000000)
__AARCH64_INSN_FUNCS(movz, 0x7F800000, 0x52800000)
__AARCH64_INSN_FUNCS(ubfm, 0x7F800000, 0x53000000)
__AARCH64_INSN_FUNCS(movk, 0x7F800000, 0x72800000)
+__AARCH64_INSN_FUNCS(add, 0x7F200000, 0x0B000000)
+__AARCH64_INSN_FUNCS(adds, 0x7F200000, 0x2B000000)
+__AARCH64_INSN_FUNCS(sub, 0x7F200000, 0x4B000000)
+__AARCH64_INSN_FUNCS(subs, 0x7F200000, 0x6B000000)
__AARCH64_INSN_FUNCS(b, 0xFC000000, 0x14000000)
__AARCH64_INSN_FUNCS(bl, 0xFC000000, 0x94000000)
__AARCH64_INSN_FUNCS(cbz, 0xFE000000, 0x34000000)
@@ -265,6 +270,12 @@ u32 aarch64_insn_gen_movewide(enum aarch64_insn_register dst,
int imm, int shift,
enum aarch64_insn_variant variant,
enum aarch64_insn_movewide_type type);
+u32 aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,
+ enum aarch64_insn_register src,
+ enum aarch64_insn_register reg,
+ int shift,
+ enum aarch64_insn_variant variant,
+ enum aarch64_insn_adsb_type type);

bool aarch64_insn_hotpatch_safe(u32 old_insn, u32 new_insn);

diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c
index 7aa2784..d7a4dd4 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -260,6 +260,7 @@ u32 __kprobes aarch64_insn_encode_immediate(enum aarch64_insn_imm_type type,
mask = BIT(7) - 1;
shift = 15;
break;
+ case AARCH64_INSN_IMM_6:
case AARCH64_INSN_IMM_S:
mask = BIT(6) - 1;
shift = 10;
@@ -698,3 +699,51 @@ u32 aarch64_insn_gen_movewide(enum aarch64_insn_register dst,

return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_16, insn, imm);
}
+
+u32 aarch64_insn_gen_add_sub_shifted_reg(enum aarch64_insn_register dst,
+ enum aarch64_insn_register src,
+ enum aarch64_insn_register reg,
+ int shift,
+ enum aarch64_insn_variant variant,
+ enum aarch64_insn_adsb_type type)
+{
+ u32 insn;
+
+ switch (type) {
+ case AARCH64_INSN_ADSB_ADD:
+ insn = aarch64_insn_get_add_value();
+ break;
+ case AARCH64_INSN_ADSB_SUB:
+ insn = aarch64_insn_get_sub_value();
+ break;
+ case AARCH64_INSN_ADSB_ADD_SETFLAGS:
+ insn = aarch64_insn_get_adds_value();
+ break;
+ case AARCH64_INSN_ADSB_SUB_SETFLAGS:
+ insn = aarch64_insn_get_subs_value();
+ break;
+ default:
+ BUG_ON(1);
+ }
+
+ switch (variant) {
+ case AARCH64_INSN_VARIANT_32BIT:
+ BUG_ON(shift & ~(SZ_32 - 1));
+ break;
+ case AARCH64_INSN_VARIANT_64BIT:
+ insn |= AARCH64_INSN_SF_BIT;
+ BUG_ON(shift & ~(SZ_64 - 1));
+ break;
+ default:
+ BUG_ON(1);
+ }
+
+
+ insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst);
+
+ insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src);
+
+ insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, reg);
+
+ return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_6, insn, shift);
+}
--
1.9.1

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