[RFC v5 33/57] objtool: arm64: Decode FP/SIMD load/store instructions

Julien Thierry jthierry at redhat.com
Thu Jan 9 08:02:36 PST 2020


Decode load/store instruction acting on floating point and SIMD
registers.

Suggested-by: Raphael Gault <raphael.gault at arm.com>
Signed-off-by: Julien Thierry <jthierry at redhat.com>
---
 tools/objtool/arch/arm64/decode.c             | 301 ++++++++++++++++++
 .../objtool/arch/arm64/include/insn_decode.h  |  12 +
 2 files changed, 313 insertions(+)

diff --git a/tools/objtool/arch/arm64/decode.c b/tools/objtool/arch/arm64/decode.c
index 2aaac4e3786c..7d480efe0bc2 100644
--- a/tools/objtool/arch/arm64/decode.c
+++ b/tools/objtool/arch/arm64/decode.c
@@ -810,6 +810,26 @@ int arm_decode_br_uncond_reg(u32 instr, enum insn_type *type,
 #undef INSN_DRPS_MASK
 
 static struct aarch64_insn_decoder ld_st_decoder[] = {
+	{
+		.mask = 0b101111111111100,
+		.value = 0b000010000000000,
+		.decode_func = arm_decode_adv_simd_mult,
+	},
+	{
+		.mask = 0b101111110000000,
+		.value = 0b000010100000000,
+		.decode_func = arm_decode_adv_simd_mult_post,
+	},
+	{
+		.mask = 0b101111101111100,
+		.value = 0b000011000000000,
+		.decode_func = arm_decode_adv_simd_single,
+	},
+	{
+		.mask = 0b101111100000000,
+		.value = 0b000011100000000,
+		.decode_func = arm_decode_adv_simd_single_post,
+	},
 	{
 		.mask = 0b001101100000000,
 		.value = 0b001000000000000,
@@ -889,6 +909,287 @@ int arm_decode_ld_st(u32 instr, enum insn_type *type,
 	return arm_decode_unknown(instr, type, immediate, ops_list);
 }
 
+static int adv_simd_mult_fields[] = {
+	0b00000,
+	0b00010,
+	0b00100,
+	0b00110,
+	0b00111,
+	0b01000,
+	0b01010,
+	0b10000,
+	0b10010,
+	0b10100,
+	0b10110,
+	0b10111,
+	0b11000,
+	0b11010,
+};
+
+int arm_decode_adv_simd_mult(u32 instr, enum insn_type *type,
+			     unsigned long *immediate,
+			     struct list_head *ops_list)
+{
+	unsigned char L = 0, opcode = 0, rn = 0;
+	unsigned char decode_field = 0;
+	int i = 0;
+
+	L = EXTRACT_BIT(instr, 22);
+	opcode = (instr >> 12) & ONES(4);
+
+	decode_field = (L << 4) | opcode;
+	rn = (instr >> 5) & ONES(5);
+	*type = INSN_OTHER;
+
+	for (i = 0; i < ARRAY_SIZE(adv_simd_mult_fields); i++) {
+		if ((decode_field & 0b11111) == adv_simd_mult_fields[i]) {
+			if (!stack_related_reg(rn))
+				return 0;
+		}
+	}
+
+	return arm_decode_unknown(instr, type, immediate, ops_list);
+}
+
+int arm_decode_adv_simd_mult_post(u32 instr, enum insn_type *type,
+				  unsigned long *immediate,
+				  struct list_head *ops_list)
+{
+	/* same opcode as for the no offset variant */
+	int ret = 0;
+
+	ret = arm_decode_adv_simd_mult(instr, type, immediate, ops_list);
+
+	/* TODO: Create stack_op for post increment with immediate */
+	return ret;
+}
+
+static struct aarch64_insn_decoder simd_single_decoder[] = {
+	{
+		.mask = 0b11111000,
+		.value = 0b00000000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111000,
+		.value = 0b00001000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b00010000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b00011000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b00100000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b00100001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b00101000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b00101001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111000,
+		.value = 0b01000000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111000,
+		.value = 0b01001000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b01010000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b01011000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b01100000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b01100001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b01101000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b01101001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111000,
+		.value = 0b10000000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111000,
+		.value = 0b10001000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b10010000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b10011000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b10100000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b10100001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b10101000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b10101001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111100,
+		.value = 0b10110000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111100,
+		.value = 0b10111000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11000000,
+		.value = 0b11111000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111000,
+		.value = 0b11001000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b11010000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111001,
+		.value = 0b11011000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b11100000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b11100001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111011,
+		.value = 0b11101000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111111,
+		.value = 0b11101001,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111100,
+		.value = 0b11110000,
+		.decode_func = NULL,
+	},
+	{
+		.mask = 0b11111100,
+		.value = 0b11111000,
+		.decode_func = NULL,
+	},
+};
+
+int arm_decode_adv_simd_single(u32 instr, enum insn_type *type,
+			       unsigned long *immediate,
+			       struct list_head *ops_list)
+{
+	unsigned char L = 0, R = 0, S = 0, opcode = 0, size = 0;
+	unsigned char rn = 0, dfield = 0;
+	int i = 0;
+
+	L = EXTRACT_BIT(instr, 22);
+	R = EXTRACT_BIT(instr, 21);
+	S = EXTRACT_BIT(instr, 12);
+	opcode = (instr >> 13) & ONES(3);
+	size = (instr >> 10) & ONES(2);
+
+	dfield = (L << 7) | (R << 6) | (opcode << 3) | (S << 2) | size;
+
+	*type = INSN_OTHER;
+	rn = (instr << 5) & ONES(5);
+
+	for (i = 0; i < ARRAY_SIZE(simd_single_decoder); i++) {
+		if ((dfield & simd_single_decoder[i].mask) ==
+		    simd_single_decoder[i].value) {
+			if (!stack_related_reg(rn))
+				return 0;
+		}
+	}
+
+	return arm_decode_unknown(instr, type, immediate, ops_list);
+}
+
+int arm_decode_adv_simd_single_post(u32 instr, enum insn_type *type,
+				    unsigned long *immediate,
+				    struct list_head *ops_list)
+{
+	/* same opcode as for the no offset variant */
+	int ret = 0;
+
+	ret = arm_decode_adv_simd_single(instr, type, immediate, ops_list);
+
+	/* TODO: Create stack_op for post increment with immediate */
+	return ret;
+}
+
 int arm_decode_ld_st_regs_unsc_imm(u32 instr, enum insn_type *type,
 				   unsigned long *immediate,
 				   struct list_head *ops_list)
diff --git a/tools/objtool/arch/arm64/include/insn_decode.h b/tools/objtool/arch/arm64/include/insn_decode.h
index caeb40942b18..7fd333f88612 100644
--- a/tools/objtool/arch/arm64/include/insn_decode.h
+++ b/tools/objtool/arch/arm64/include/insn_decode.h
@@ -94,6 +94,18 @@ int arm_decode_br_uncond_reg(u32 instr, enum insn_type *type,
 			     struct list_head *ops_list);
 
 /* arm64 load/store instructions */
+int arm_decode_adv_simd_mult(u32 instr, enum insn_type *type,
+			     unsigned long *immediate,
+			     struct list_head *ops_list);
+int arm_decode_adv_simd_mult_post(u32 instr, enum insn_type *type,
+				  unsigned long *immediate,
+				  struct list_head *ops_list);
+int arm_decode_adv_simd_single(u32 instr, enum insn_type *type,
+			       unsigned long *immediate,
+			       struct list_head *ops_list);
+int arm_decode_adv_simd_single_post(u32 instr, enum insn_type *type,
+				    unsigned long *immediate,
+				    struct list_head *ops_list);
 int arm_decode_ld_st_noalloc_pair_off(u32 instr, enum insn_type *type,
 				      unsigned long *immediate,
 				      struct list_head *ops_list);
-- 
2.21.0




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