The file just provides the function get_arch_regstr, however, if in
the only caller get_dwarf_regstr EM_HOST is used for the EM_NONE case,
and the register table is provided in a header file, the function can
never be called. So remove as dead code. Tidy up the EM_NONE cases for
riscv in dwarf-regs.c.

Signed-off-by: Ian Rogers <irogers@google.com>
---
 .../dwarf-regs-table.h}                       | 32 ++++---------------
 tools/perf/arch/riscv/util/Build              |  1 -
 tools/perf/util/dwarf-regs.c                  |  7 ++--
 tools/perf/util/include/dwarf-regs.h          |  2 +-
 4 files changed, 12 insertions(+), 30 deletions(-)
 rename tools/perf/arch/riscv/{util/dwarf-regs.c => include/dwarf-regs-table.h} (56%)

diff --git a/tools/perf/arch/riscv/util/dwarf-regs.c b/tools/perf/arch/riscv/include/dwarf-regs-table.h
similarity index 56%
rename from tools/perf/arch/riscv/util/dwarf-regs.c
rename to tools/perf/arch/riscv/include/dwarf-regs-table.h
index a9c4402ae57e..a45b63a6d5a8 100644
--- a/tools/perf/arch/riscv/util/dwarf-regs.c
+++ b/tools/perf/arch/riscv/include/dwarf-regs-table.h
@@ -1,23 +1,10 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
- * Mapping of DWARF debug register numbers into register names.
- */
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+/* This is included in perf/util/dwarf-regs.c */
 
-#include <stddef.h>
-#include <errno.h> /* for EINVAL */
-#include <string.h> /* for strcmp */
-#include <dwarf-regs.h>
+#define REG_DWARFNUM_NAME(reg, idx)	[idx] = "%" #reg
 
-struct regs_dwarfnum {
-	const char *name;
-	unsigned int dwarfnum;
-};
-
-#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
-#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
-
-struct regs_dwarfnum riscv_dwarf_regs_table[] = {
+static const char * const riscv_regstr_tbl[] = {
 	REG_DWARFNUM_NAME("%zero", 0),
 	REG_DWARFNUM_NAME("%ra", 1),
 	REG_DWARFNUM_NAME("%sp", 2),
@@ -50,13 +37,6 @@ struct regs_dwarfnum riscv_dwarf_regs_table[] = {
 	REG_DWARFNUM_NAME("%t4", 29),
 	REG_DWARFNUM_NAME("%t5", 30),
 	REG_DWARFNUM_NAME("%t6", 31),
-	REG_DWARFNUM_END,
 };
 
-#define RISCV_MAX_REGS ((sizeof(riscv_dwarf_regs_table) / \
-		 sizeof(riscv_dwarf_regs_table[0])) - 1)
-
-const char *get_arch_regstr(unsigned int n)
-{
-	return (n < RISCV_MAX_REGS) ? riscv_dwarf_regs_table[n].name : NULL;
-}
+#endif
diff --git a/tools/perf/arch/riscv/util/Build b/tools/perf/arch/riscv/util/Build
index 8f93091b8345..58a672246024 100644
--- a/tools/perf/arch/riscv/util/Build
+++ b/tools/perf/arch/riscv/util/Build
@@ -2,5 +2,4 @@ perf-util-y += perf_regs.o
 perf-util-y += header.o
 
 perf-util-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o
-perf-util-$(CONFIG_LIBDW) += dwarf-regs.o
 perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
index 3d98c2bf6035..2c6b197556dd 100644
--- a/tools/perf/util/dwarf-regs.c
+++ b/tools/perf/util/dwarf-regs.c
@@ -20,6 +20,7 @@
 #include "../arch/arm64/include/dwarf-regs-table.h"
 #include "../arch/sh/include/dwarf-regs-table.h"
 #include "../arch/powerpc/include/dwarf-regs-table.h"
+#include "../arch/riscv/include/dwarf-regs-table.h"
 #include "../arch/s390/include/dwarf-regs-table.h"
 #include "../arch/sparc/include/dwarf-regs-table.h"
 #include "../arch/xtensa/include/dwarf-regs-table.h"
@@ -33,7 +34,7 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int
 {
 #if EM_HOST == EM_X86_64 || EM_HOST == EM_386 || EM_HOST == EM_AARCH64 || EM_HOST == EM_ARM \
     || EM_HOST == EM_CSKY || EM_HOST == EM_LOONGARCH || EM_HOST == EM_MIPS || EM_HOST == EM_PPC \
-    || EM_HOST == EM_PPC64
+    || EM_HOST == EM_PPC64 || EM_HOST == EM_RISCV
 	if (machine == EM_NONE) {
 		/* Generic arch - use host arch */
 		machine = EM_HOST;
@@ -42,7 +43,7 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int
 	switch (machine) {
 #if EM_HOST != EM_X86_64 && EM_HOST != EM_386 && EM_HOST != EM_AARCH64 && EM_HOST != EM_ARM \
     && EM_HOST != EM_CSKY && EM_HOST != EM_LOONGARCH && EM_HOST != EM_MIPS && EM_HOST != EM_PPC \
-    && EM_HOST != EM_PPC64
+    && EM_HOST != EM_PPC64 && EM_HOST != EM_RISCV
 	case EM_NONE:	/* Generic arch - use host arch */
 		return get_arch_regstr(n);
 #endif
@@ -63,6 +64,8 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int
 	case EM_PPC:
 	case EM_PPC64:
 		return __get_dwarf_regstr(powerpc_regstr_tbl, n);
+	case EM_RISCV:
+		return __get_dwarf_regstr(riscv_regstr_tbl, n);
 	case EM_SPARC:
 	case EM_SPARCV9:
 		return __get_dwarf_regstr(sparc_regstr_tbl, n);
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index 1763280855ce..35f4f33205da 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -81,7 +81,7 @@
 #ifdef HAVE_LIBDW_SUPPORT
 #if !defined(__x86_64__) && !defined(__i386__) && !defined(__aarch64__) && !defined(__arm__) \
     && !defined(__loongarch__) && !defined(__mips__) && !defined(__powerpc__) \
-    && !defined(__powerpc64__)
+    && !defined(__powerpc64__) && !defined(__riscv__)
 const char *get_arch_regstr(unsigned int n);
 #endif
 
-- 
2.47.0.rc0.187.ge670bccf7e-goog