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
the function can never be called. So remove as dead code. Tidy up the
EM_NONE cases for arm64 in dwarf-regs.c.

Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/arch/arm64/util/Build        |  1 -
 tools/perf/arch/arm64/util/dwarf-regs.c | 80 -------------------------
 tools/perf/util/dwarf-regs.c            |  4 +-
 tools/perf/util/include/dwarf-regs.h    |  2 +-
 4 files changed, 3 insertions(+), 84 deletions(-)
 delete mode 100644 tools/perf/arch/arm64/util/dwarf-regs.c

diff --git a/tools/perf/arch/arm64/util/Build b/tools/perf/arch/arm64/util/Build
index 4387a6d6a6c3..a74521b79eaa 100644
--- a/tools/perf/arch/arm64/util/Build
+++ b/tools/perf/arch/arm64/util/Build
@@ -4,7 +4,6 @@ perf-util-y += perf_regs.o
 perf-util-y += tsc.o
 perf-util-y += pmu.o
 perf-util-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o
-perf-util-$(CONFIG_LIBDW)     += dwarf-regs.o
 perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
 perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 
diff --git a/tools/perf/arch/arm64/util/dwarf-regs.c b/tools/perf/arch/arm64/util/dwarf-regs.c
deleted file mode 100644
index 343a62fa4199..000000000000
--- a/tools/perf/arch/arm64/util/dwarf-regs.c
+++ /dev/null
@@ -1,80 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Mapping of DWARF debug register numbers into register names.
- *
- * Copyright (C) 2010 Will Deacon, ARM Ltd.
- */
-
-#include <errno.h>
-#include <stddef.h>
-#include <string.h>
-#include <dwarf-regs.h>
-#include <linux/stringify.h>
-
-struct regs_dwarfnum {
-	const char *name;
-	unsigned int dwarfnum;
-};
-
-#define REG_DWARFNUM_NAME(r, num) {.name = r, .dwarfnum = num}
-#define GPR_DWARFNUM_NAME(num) \
-	{.name = __stringify(%x##num), .dwarfnum = num}
-#define REG_DWARFNUM_END {.name = NULL, .dwarfnum = 0}
-
-/*
- * Reference:
- * http://infocenter.arm.com/help/topic/com.arm.doc.ihi0057b/IHI0057B_aadwarf64.pdf
- */
-static const struct regs_dwarfnum regdwarfnum_table[] = {
-	GPR_DWARFNUM_NAME(0),
-	GPR_DWARFNUM_NAME(1),
-	GPR_DWARFNUM_NAME(2),
-	GPR_DWARFNUM_NAME(3),
-	GPR_DWARFNUM_NAME(4),
-	GPR_DWARFNUM_NAME(5),
-	GPR_DWARFNUM_NAME(6),
-	GPR_DWARFNUM_NAME(7),
-	GPR_DWARFNUM_NAME(8),
-	GPR_DWARFNUM_NAME(9),
-	GPR_DWARFNUM_NAME(10),
-	GPR_DWARFNUM_NAME(11),
-	GPR_DWARFNUM_NAME(12),
-	GPR_DWARFNUM_NAME(13),
-	GPR_DWARFNUM_NAME(14),
-	GPR_DWARFNUM_NAME(15),
-	GPR_DWARFNUM_NAME(16),
-	GPR_DWARFNUM_NAME(17),
-	GPR_DWARFNUM_NAME(18),
-	GPR_DWARFNUM_NAME(19),
-	GPR_DWARFNUM_NAME(20),
-	GPR_DWARFNUM_NAME(21),
-	GPR_DWARFNUM_NAME(22),
-	GPR_DWARFNUM_NAME(23),
-	GPR_DWARFNUM_NAME(24),
-	GPR_DWARFNUM_NAME(25),
-	GPR_DWARFNUM_NAME(26),
-	GPR_DWARFNUM_NAME(27),
-	GPR_DWARFNUM_NAME(28),
-	GPR_DWARFNUM_NAME(29),
-	REG_DWARFNUM_NAME("%lr", 30),
-	REG_DWARFNUM_NAME("%sp", 31),
-	REG_DWARFNUM_END,
-};
-
-/**
- * get_arch_regstr() - lookup register name from it's DWARF register number
- * @n:	the DWARF register number
- *
- * get_arch_regstr() returns the name of the register in struct
- * regdwarfnum_table from it's DWARF register number. If the register is not
- * found in the table, this returns NULL;
- */
-const char *get_arch_regstr(unsigned int n)
-{
-	const struct regs_dwarfnum *roff;
-
-	for (roff = regdwarfnum_table; roff->name != NULL; roff++)
-		if (roff->dwarfnum == n)
-			return roff->name;
-	return NULL;
-}
diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
index eac99a246737..18e916c8e993 100644
--- a/tools/perf/util/dwarf-regs.c
+++ b/tools/perf/util/dwarf-regs.c
@@ -32,14 +32,14 @@
 const char *get_dwarf_regstr(unsigned int n, unsigned int machine,
 			     unsigned int flags __maybe_unused)
 {
-#if EM_HOST == EM_X86_64 || EM_HOST == EM_386
+#if EM_HOST == EM_X86_64 || EM_HOST == EM_386 || EM_HOST == EM_AARCH64
 	if (machine == EM_NONE) {
 		/* Generic arch - use host arch */
 		machine = EM_HOST;
 	}
 #endif
 	switch (machine) {
-#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
+#if EM_HOST != EM_X86_64 && EM_HOST != EM_386 && EM_HOST != EM_AARCH64
 	case EM_NONE:	/* Generic arch - use host arch */
 		return get_arch_regstr(n);
 #endif
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index 6aa66c375942..f976528fdfd6 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -89,7 +89,7 @@
 #define DWARF_REG_FB  0xd3affb /* random number */
 
 #ifdef HAVE_LIBDW_SUPPORT
-#if !defined(__x86_64__) && !defined(__i386__)
+#if !defined(__x86_64__) && !defined(__i386__) && !defined(__aarch64__)
 const char *get_arch_regstr(unsigned int n);
 #endif
 
-- 
2.47.0.277.g8800431eea-goog