perf loongarch: Remove dwarf-regs.c

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 loongarch in dwarf-regs.c.

Reviewed-by: Masami Hiramatsu (Google) <[e-mail]>
Signed-off-by: Ian Rogers <[e-mail]>
Cc: Anup Patel <[e-mail]>
Cc: Yang Jihong <[e-mail]>
Cc: Palmer Dabbelt <[e-mail]>
Cc: David S. Miller <[e-mail]>
Cc: Albert Ou <[e-mail]>
Cc: Shenlin Liang <[e-mail]>
Cc: Nick Terrell <[e-mail]>
Cc: Guilherme Amadio <[e-mail]>
Cc: Steinar H. Gunderson <[e-mail]>
Cc: Changbin Du <[e-mail]>
Cc: Alexander Lobakin <[e-mail]>
Cc: Przemek Kitszel <[e-mail]>
Cc: Huacai Chen <[e-mail]>
Cc: Guo Ren <[e-mail]>
Cc: Masahiro Yamada <[e-mail]>
Cc: Will Deacon <[e-mail]>
Cc: James Clark <[e-mail]>
Cc: Mike Leach <[e-mail]>
Cc: Chen Pei <[e-mail]>
Cc: Leo Yan <[e-mail]>
Cc: Oliver Upton <[e-mail]>
Cc: Aditya Gupta <[e-mail]>
Cc: Kajol Jain <[e-mail]>
Cc: Athira Rajeev <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: Bibo Mao <[e-mail]>
Cc: John Garry <[e-mail]>
Cc: Atish Patra <[e-mail]>
Cc: Dima Kogan <[e-mail]>
Cc: Paul Walmsley <[e-mail]>
Cc: Dr. David Alan Gilbert <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/arch/loongarch/util/Build

···
 perf-util-y += header.o
 perf-util-y += perf_regs.o
 
-perf-util-$(CONFIG_LIBDW)     += dwarf-regs.o
 perf-util-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
 perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 perf-util-$(CONFIG_LIBTRACEEVENT) += kvm-stat.o

tools/perf/arch/loongarch/util/dwarf-regs.c

···
-// SPDX-License-Identifier: GPL-2.0
-/*
- * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
- *
- * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
- */
-
-#include <stdio.h>
-#include <errno.h> /* for EINVAL */
-#include <string.h> /* for strcmp */
-#include <dwarf-regs.h>
-
-struct pt_regs_dwarfnum {
-	const char *name;
-	unsigned int dwarfnum;
-};
-
-static struct pt_regs_dwarfnum loongarch_gpr_table[] = {
-	{"%r0", 0}, {"%r1", 1}, {"%r2", 2}, {"%r3", 3},
-	{"%r4", 4}, {"%r5", 5}, {"%r6", 6}, {"%r7", 7},
-	{"%r8", 8}, {"%r9", 9}, {"%r10", 10}, {"%r11", 11},
-	{"%r12", 12}, {"%r13", 13}, {"%r14", 14}, {"%r15", 15},
-	{"%r16", 16}, {"%r17", 17}, {"%r18", 18}, {"%r19", 19},
-	{"%r20", 20}, {"%r21", 21}, {"%r22", 22}, {"%r23", 23},
-	{"%r24", 24}, {"%r25", 25}, {"%r26", 26}, {"%r27", 27},
-	{"%r28", 28}, {"%r29", 29}, {"%r30", 30}, {"%r31", 31},
-	{NULL, 0}
-};
-
-const char *get_arch_regstr(unsigned int n)
-{
-	n %= 32;
-	return loongarch_gpr_table[n].name;
-}

tools/perf/util/dwarf-regs.c

···
 const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int flags)
 {
 #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_CSKY || EM_HOST == EM_LOONGARCH
 	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 && EM_HOST != EM_AARCH64 && EM_HOST != EM_ARM \
-    && EM_HOST != EM_CSKY
+    && EM_HOST != EM_CSKY && EM_HOST != EM_LOONGARCH
 	case EM_NONE:	/* Generic arch - use host arch */
 		return get_arch_regstr(n);
 #endif

tools/perf/util/include/dwarf-regs.h

···
 #define DWARF_REG_FB  0xd3affb /* random number */
 
 #ifdef HAVE_LIBDW_SUPPORT
-#if !defined(__x86_64__) && !defined(__i386__) && !defined(__aarch64__) && !defined(__arm__)
+#if !defined(__x86_64__) && !defined(__i386__) && !defined(__aarch64__) && !defined(__arm__) \
+    && !defined(__loongarch__)
 const char *get_arch_regstr(unsigned int n);
 #endif