[PATCH v5 04/26] perf annotate-arm64: Handle load and store instructions

[Tengda Wu]

Add ldst_ops to handle load and store instructions in order to parse
the data types and offsets associated with PMU events for memory access
instructions. There are many variants of load and store instructions in
arm64, making it difficult to match all of these instruction names
completely. Therefore, only the instruction prefixes are matched. The
prefix 'ld|st' covers most of the memory access instructions, 'cas|swp'
matches atomic instructions, and 'prf' matches memory prefetch
instructions.

Signed-off-by: Li Huafei <lihuafei1@xxxxxxxxxx>
Signed-off-by: Tengda Wu <wutengda@xxxxxxxxxxxxxxx>
---
 .../perf/util/annotate-arch/annotate-arm64.c  | 140 ++++++++++++++++++
 1 file changed, 140 insertions(+)

diff --git a/tools/perf/util/annotate-arch/annotate-arm64.c b/tools/perf/util/annotate-arch/annotate-arm64.c
index 151184210691..a7595a954cfa 100644
--- a/tools/perf/util/annotate-arch/annotate-arm64.c
+++ b/tools/perf/util/annotate-arch/annotate-arm64.c
@@ -14,6 +14,7 @@ struct arch_arm64 {
 	struct arch arch;
 	regex_t call_insn;
 	regex_t jump_insn;
+	regex_t ldst_insn; /* load and store instruction */
 };
 
 static bool arm64__is_reg(const char *op)
@@ -170,6 +171,130 @@ static const struct ins_ops arm64_mov_ops = {
 	.scnprintf = arm64_mov__scnprintf,
 };
 
+static bool arm64__insn_is_target_on_right(const char *ins_name)
+{
+	/*
+	 * Store instructions write to the memory operand on the right,
+	 * unlike standard syntax where the target is the left operand.
+	 */
+	return !strncmp(ins_name, "st", 2);
+}
+
+/*
+ * This function is used to parse arm64 load/store instructions into
+ * instruction operands.
+ *
+ * Typical instructions and their parsing logic:
+ *
+ * 1. Immediate offset:
+ *    ldr   x2, [x0]                -> target="x2", source="[x0]"
+ *    ldr   x2, [x0, #24]           -> target="x2", source="[x0, #24]"
+ *    ldp   x19, x20, [sp, #16]     -> target="x19, x20", source="[sp, #16]"
+ *
+ * 2. Pre-index addressing:
+ *    stp   x29, x30, [sp, #-64]!   -> target="[sp, #-64]!", source="x29, x30"
+ *
+ * 3. Post-index addressing:
+ *    str   x1, [x0], #8            -> target="[x0], #8", source="x1"
+ *    ldr   w1, [x21], #4           -> target="w1", source="[x21], #4"
+ *    ldp   x29, x30, [sp], #32     -> target="x29, x30", source="[sp], #32"
+ *
+ * 4. Register offset / extension:
+ *    ldr   x0, [x1, w0, sxtw #3]   -> target="x0", source="[x1, w0, sxtw #3]"
+ *    ldr   x0, [x1, x0, lsl #3]    -> target="x0", source="[x1, x0, lsl #3]"
+ *
+ * 5. Atomic operations:
+ *    cas   w3, w1, [x0]            -> target="w3, w1", source="[x0]"
+ *    swp   x3, x0, [x2]            -> target="x3, x0", source="[x2]"
+ *
+ * 6. Prefetch memory:
+ *    prfm  pstl1strm, [x4]         -> target="pstl1strm", source="[x4]"
+ *
+ * 7. PC-relative loads (No bracket found):
+ *    ldr   x0, ffff800080f40c68 <__kvm_nvhe_$d>  -> Fallback to default parser
+ *
+ * Parsing strategy:
+ * Use the '[' bracket as the boundary to split the operands into left
+ * and right sides. For non-store instructions, the left side is the
+ * target and the right side is the source. For store instructions, the
+ * roles are reversed.
+ */
+static int arm64_ldst__parse(const struct arch *arch, struct ins_operands *ops,
+			     struct map_symbol *ms, struct disasm_line *dl)
+{
+	char *raw, *s, *left, *right;
+	int ret = -1;
+
+	raw = rstrip_space_and_comment(ops->raw, arch->objdump.comment_char);
+	if (!raw)
+		return -1;
+
+	s = strchr(raw, arch->objdump.memory_ref_char);
+	if (!s) {
+		/* Fallback to default parser for PC-relative loads. */
+		free(raw);
+		return arm64_mov__parse(arch, ops, ms, dl);
+	}
+
+	right = strdup(s);
+	if (!right)
+		goto out_free_raw;
+
+	while (s > raw && *s != ',')
+		--s;
+
+	if (s == raw)
+		goto out_free_right;
+
+	*s = '\0';
+	left = strdup(raw);
+	*s = ',';
+	if (!left)
+		goto out_free_right;
+
+	free(raw);
+
+	if (arm64__insn_is_target_on_right(dl->ins.name)) {
+		ops->source.raw = left;
+		ops->source.mem_ref = false;
+
+		ops->target.raw = right;
+		ops->target.mem_ref = true;
+	} else {
+		ops->source.raw = right;
+		ops->source.mem_ref = true;
+
+		ops->target.raw = left;
+		ops->target.mem_ref = false;
+	}
+
+	ops->source.multi_regs = arm64__check_multi_regs(arch, ops->source.raw);
+	ops->target.multi_regs = arm64__check_multi_regs(arch, ops->target.raw);
+
+	return 0;
+
+out_free_right:
+	free(right);
+out_free_raw:
+	free(raw);
+	return ret;
+}
+
+static int arm64_ldst__scnprintf(const struct ins *ins, char *bf, size_t size,
+				 struct ins_operands *ops, int max_ins_name)
+{
+	if (arm64__insn_is_target_on_right(ins->name))
+		return scnprintf(bf, size, "%-*s %s", max_ins_name, ins->name, ops->raw);
+
+	return scnprintf(bf, size, "%-*s %s, %s", max_ins_name, ins->name,
+			 ops->target.raw, ops->source.name ?: ops->source.raw);
+}
+
+static struct ins_ops arm64_ldst_ops = {
+	.parse	   = arm64_ldst__parse,
+	.scnprintf = arm64_ldst__scnprintf,
+};
+
 static const struct ins_ops *arm64__associate_instruction_ops(struct arch *arch, const char *name)
 {
 	struct arch_arm64 *arm = container_of(arch, struct arch_arm64, arch);
@@ -180,6 +305,8 @@ static const struct ins_ops *arm64__associate_instruction_ops(struct arch *arch,
 		ops = &jump_ops;
 	else if (!regexec(&arm->call_insn, name, 2, match, 0))
 		ops = &call_ops;
+	else if (!regexec(&arm->ldst_insn, name, 2, match, 0))
+		ops = &arm64_ldst_ops;
 	else if (!strcmp(name, "ret"))
 		ops = &ret_ops;
 	else
@@ -205,6 +332,7 @@ const struct arch *arch__new_arm64(const struct e_machine_and_e_flags *id,
 	arch->objdump.comment_char	  = '/';
 	arch->objdump.skip_functions_char = '+';
 	arch->objdump.memory_ref_char	  = '[';
+	arch->objdump.imm_char		  = '#';
 	arch->associate_instruction_ops   = arm64__associate_instruction_ops;
 
 	/* bl, blr */
@@ -218,8 +346,20 @@ const struct arch *arch__new_arm64(const struct e_machine_and_e_flags *id,
 	if (err)
 		goto out_free_call;
 
+	/*
+	 * The ARM64 architecture has many variants of load/store instructions.
+	 * It is quite challenging to match all of them completely. Here, we
+	 * only match the prefixes of these instructions.
+	 */
+	err = regcomp(&arm->ldst_insn, "^(ld|st|cas|prf|swp)",
+		      REG_EXTENDED);
+	if (err)
+		goto out_free_jump;
+
 	return arch;
 
+out_free_jump:
+	regfree(&arm->jump_insn);
 out_free_call:
 	regfree(&arm->call_insn);
 out_free_arm:
-- 
2.34.1