[PATCH RFCv3 04/14] arm64: introduce aarch64_insn_gen_load_store_reg()

From: Zi Shen Lim
Date: Tue Jul 15 2014 - 02:27:56 EST


Introduce function to generate load/store (register offset)
instructions.

Signed-off-by: Zi Shen Lim <zlim.lnx@xxxxxxxxx>
---
arch/arm64/include/asm/insn.h | 20 ++++++++++++++
arch/arm64/kernel/insn.c | 62 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+)

diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
index 86a8a9c..5bc1cc3 100644
--- a/arch/arm64/include/asm/insn.h
+++ b/arch/arm64/include/asm/insn.h
@@ -72,6 +72,7 @@ enum aarch64_insn_imm_type {
enum aarch64_insn_register_type {
AARCH64_INSN_REGTYPE_RT,
AARCH64_INSN_REGTYPE_RN,
+ AARCH64_INSN_REGTYPE_RM,
};

enum aarch64_insn_register {
@@ -143,12 +144,26 @@ enum aarch64_insn_branch_type {
AARCH64_INSN_BRANCH_COMP_NONZERO,
};

+enum aarch64_insn_size_type {
+ AARCH64_INSN_SIZE_8,
+ AARCH64_INSN_SIZE_16,
+ AARCH64_INSN_SIZE_32,
+ AARCH64_INSN_SIZE_64,
+};
+
+enum aarch64_insn_ldst_type {
+ AARCH64_INSN_LDST_LOAD_REG_OFFSET,
+ AARCH64_INSN_LDST_STORE_REG_OFFSET,
+};
+
#define __AARCH64_INSN_FUNCS(abbr, mask, val) \
static __always_inline bool aarch64_insn_is_##abbr(u32 code) \
{ return (code & (mask)) == (val); } \
static __always_inline u32 aarch64_insn_get_##abbr##_value(void) \
{ return (val); }

+__AARCH64_INSN_FUNCS(str_reg, 0x3FE0EC00, 0x38206800)
+__AARCH64_INSN_FUNCS(ldr_reg, 0x3FE0EC00, 0x38606800)
__AARCH64_INSN_FUNCS(b, 0xFC000000, 0x14000000)
__AARCH64_INSN_FUNCS(bl, 0xFC000000, 0x94000000)
__AARCH64_INSN_FUNCS(cbz, 0xFE000000, 0x34000000)
@@ -184,6 +199,11 @@ u32 aarch64_insn_gen_hint(enum aarch64_insn_hint_op op);
u32 aarch64_insn_gen_nop(void);
u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,
enum aarch64_insn_branch_type type);
+u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,
+ enum aarch64_insn_register base,
+ enum aarch64_insn_register offset,
+ enum aarch64_insn_size_type size,
+ enum aarch64_insn_ldst_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 f2cf8ab..447ad63 100644
--- a/arch/arm64/kernel/insn.c
+++ b/arch/arm64/kernel/insn.c
@@ -284,6 +284,9 @@ static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
case AARCH64_INSN_REGTYPE_RN:
shift = 5;
break;
+ case AARCH64_INSN_REGTYPE_RM:
+ shift = 16;
+ break;
default:
pr_err("%s: unknown register type encoding %d\n", __func__,
type);
@@ -296,6 +299,35 @@ static u32 aarch64_insn_encode_register(enum aarch64_insn_register_type type,
return insn;
}

+static u32 aarch64_insn_encode_ldst_size(enum aarch64_insn_size_type type,
+ u32 insn)
+{
+ u32 size;
+
+ switch (type) {
+ case AARCH64_INSN_SIZE_8:
+ size = 0;
+ break;
+ case AARCH64_INSN_SIZE_16:
+ size = 1;
+ break;
+ case AARCH64_INSN_SIZE_32:
+ size = 2;
+ break;
+ case AARCH64_INSN_SIZE_64:
+ size = 3;
+ break;
+ default:
+ pr_err("%s: unknown size encoding %d\n", __func__, type);
+ return 0;
+ }
+
+ insn &= ~GENMASK(31, 30);
+ insn |= size << 30;
+
+ return insn;
+}
+
static inline long branch_imm_common(unsigned long pc, unsigned long addr,
long range)
{
@@ -426,3 +458,33 @@ u32 aarch64_insn_gen_branch_reg(enum aarch64_insn_register reg,

return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, reg);
}
+
+u32 aarch64_insn_gen_load_store_reg(enum aarch64_insn_register reg,
+ enum aarch64_insn_register base,
+ enum aarch64_insn_register offset,
+ enum aarch64_insn_size_type size,
+ enum aarch64_insn_ldst_type type)
+{
+ u32 insn;
+
+ switch (type) {
+ case AARCH64_INSN_LDST_LOAD_REG_OFFSET:
+ insn = aarch64_insn_get_ldr_reg_value();
+ break;
+ case AARCH64_INSN_LDST_STORE_REG_OFFSET:
+ insn = aarch64_insn_get_str_reg_value();
+ break;
+ default:
+ BUG_ON(1);
+ }
+
+ insn = aarch64_insn_encode_ldst_size(size, insn);
+
+ insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RT, insn, reg);
+
+ insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn,
+ base);
+
+ return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn,
+ offset);
+}
--
1.9.1

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