perf annotate: Add riscv64 support

This patch adds basic arch initialization and instruction associate
support for the riscv64 CPU architecture.

Example output:

  $ perf annotate --stdio2
  Samples: 122K of event 'task-clock:u', 4000 Hz, Event count (approx.): 30637250000, [percent: local period]
  strcmp() /usr/lib64/libc-2.32.so
  Percent

	      Disassembly of section .text:

	      0000000000069a30 <strcmp>:
	      __GI_strcmp():
	      const unsigned char *s2 = (const unsigned char *) p2;
	      unsigned char c1, c2;

	      do
	      {
	      c1 = (unsigned char) *s1++;
   37.30        lbu  a5,0(a0)
	      c2 = (unsigned char) *s2++;
    1.23        addi a1,a1,1
	      c1 = (unsigned char) *s1++;
   18.68        addi a0,a0,1
	      c2 = (unsigned char) *s2++;
    1.37        lbu  a4,-1(a1)
	      if (c1 == '\0')
   18.71      ↓ beqz a5,18
	       return c1 - c2;
	       }

Signed-off-by: William Cohen <wcohen@redhat.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-riscv@lists.infradead.org
Link: http://lore.kernel.org/lkml/20210927005115.610264-1-wcohen@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/arch/riscv64/annotate/instructions.c

@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+
+static
+struct ins_ops *riscv64__associate_ins_ops(struct arch *arch, const char *name)
+{
+	struct ins_ops *ops = NULL;
+
+	if (!strncmp(name, "jal", 3) ||
+	    !strncmp(name, "jr", 2) ||
+	    !strncmp(name, "call", 4))
+		ops = &call_ops;
+	else if (!strncmp(name, "ret", 3))
+		ops = &ret_ops;
+	else if (name[0] == 'j' || name[0] == 'b')
+		ops = &jump_ops;
+	else
+		return NULL;
+
+	arch__associate_ins_ops(arch, name, ops);
+
+	return ops;
+}
+
+static
+int riscv64__annotate_init(struct arch *arch, char *cpuid __maybe_unused)
+{
+	if (!arch->initialized) {
+		arch->associate_instruction_ops = riscv64__associate_ins_ops;
+		arch->initialized = true;
+		arch->objdump.comment_char = '#';
+	}
+
+	return 0;
+}

tools/perf/util/annotate.c

@@ -151,6 +151,7 @@ static int arch__associate_ins_ops(struct arch* arch, const char *name, struct i
 #include "arch/mips/annotate/instructions.c"
 #include "arch/x86/annotate/instructions.c"
 #include "arch/powerpc/annotate/instructions.c"
+#include "arch/riscv64/annotate/instructions.c"
 #include "arch/s390/annotate/instructions.c"
 #include "arch/sparc/annotate/instructions.c"
 
@@ -191,6 +192,10 @@ static struct arch architectures[] = {
 		.name = "powerpc",
 		.init = powerpc__annotate_init,
 	},
+	{
+		.name = "riscv64",
+		.init = riscv64__annotate_init,
+	},
 	{
 		.name = "s390",
 		.init = s390__annotate_init,