perf dwarf-regs: Move x86 dwarf-regs out of arch

Move arch/x86/util/dwarf-regs.c to util/dwarf-regs-x86.c and compile
in unconditionally. To avoid get_arch_regnum being duplicated, rename
to get_x86_regnum and add to get_dwarf_regnum switch.

For get_arch_regstr, this was unused on x86 unless the machine type
was EM_NONE. Map that case to EM_HOST and remove get_arch_regstr from
dwarf-regs-x86.c.

Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Anup Patel <anup@brainfault.org>
Cc: Yang Jihong <yangjihong@bytedance.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Shenlin Liang <liangshenlin@eswincomputing.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Guilherme Amadio <amadio@gentoo.org>
Cc: Steinar H. Gunderson <sesse@google.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: James Clark <james.clark@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Chen Pei <cp0613@linux.alibaba.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Aditya Gupta <adityag@linux.ibm.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-riscv@lists.infradead.org
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Atish Patra <atishp@rivosinc.com>
Cc: Dima Kogan <dima@secretsauce.net>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Dr. David Alan Gilbert <linux@treblig.org>
Cc: linux-csky@vger.kernel.org
Link: https://lore.kernel.org/r/20241108234606.429459-8-irogers@google.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

Author: captain5050

tools/perf/arch/x86/util/Build

@@ -11,9 +11,6 @@ perf-util-y += mem-events.o
 perf-util-y += evsel.o
 perf-util-y += iostat.o
 
-perf-util-$(CONFIG_LIBDW) += dwarf-regs.o
-perf-util-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
-
 perf-util-$(CONFIG_LOCAL_LIBUNWIND)    += unwind-libunwind.o
 perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
 

tools/perf/util/Build

@@ -204,6 +204,7 @@ endif
 perf-util-$(CONFIG_LIBDW) += probe-finder.o
 perf-util-$(CONFIG_LIBDW) += dwarf-aux.o
 perf-util-$(CONFIG_LIBDW) += dwarf-regs.o
+perf-util-$(CONFIG_LIBDW) += dwarf-regs-x86.o
 perf-util-$(CONFIG_LIBDW) += debuginfo.o
 perf-util-$(CONFIG_LIBDW) += annotate-data.o
 

tools/perf/arch/x86/util/dwarf-regs.c tools/perf/util/dwarf-regs-x86.ctools/perf/arch/x86/util/dwarf-regs.c renamed to tools/perf/util/dwarf-regs-x86.c

@@ -11,28 +11,6 @@
 #include <linux/kernel.h> /* for ARRAY_SIZE */
 #include <dwarf-regs.h>
 
-#define DEFINE_DWARF_REGSTR_TABLE 1
-#include "dwarf-regs-table.h"
-
-/* Return architecture dependent register string (for kprobe-tracer) */
-const char *get_arch_regstr(unsigned int n)
-{
-#if defined(__i386__)
-	size_t len = ARRAY_SIZE(x86_32_regstr_tbl);
-#else
-	size_t len = ARRAY_SIZE(x86_64_regstr_tbl);
-#endif
-
-	if (n >= len)
-		return NULL;
-
-#if defined(__i386__)
-	return x86_32_regstr_tbl[n];
-#else
-	return x86_64_regstr_tbl[n];
-#endif
-}
-
 struct dwarf_regs_idx {
 	const char *name;
 	int idx;
@@ -58,7 +36,7 @@ static const struct dwarf_regs_idx x86_regidx_table[] = {
 	{ "rip", DWARF_REG_PC },
 };
 
-int get_arch_regnum(const char *name)
+int get_x86_regnum(const char *name)
 {
 	unsigned int i;
 

tools/perf/util/dwarf-regs.c

@@ -32,9 +32,17 @@
 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 (machine == EM_NONE) {
+		/* Generic arch - use host arch */
+		machine = EM_HOST;
+	}
+#endif
 	switch (machine) {
+#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
 	case EM_NONE:	/* Generic arch - use host arch */
 		return get_arch_regstr(n);
+#endif
 	case EM_386:
 		return __get_dwarf_regstr(x86_32_regstr_tbl, n);
 	case EM_X86_64:
@@ -65,10 +73,12 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine,
 	return NULL;
 }
 
+#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
 __weak int get_arch_regnum(const char *name __maybe_unused)
 {
 	return -ENOTSUP;
 }
+#endif
 
 /* Return DWARF register number from architecture register name */
 int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags __maybe_unused)
@@ -90,9 +100,16 @@ int get_dwarf_regnum(const char *name, unsigned int machine, unsigned int flags
 		machine = EM_HOST;
 	}
 	switch (machine) {
+#if EM_HOST != EM_X86_64 && EM_HOST != EM_386
 	case EM_HOST:
 		reg = get_arch_regnum(regname);
 		break;
+#endif
+	case EM_X86_64:
+		fallthrough;
+	case EM_386:
+		reg = get_x86_regnum(regname);
+		break;
 	default:
 		pr_err("ELF MACHINE %x is not supported.\n", machine);
 	}

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

@@ -89,7 +89,10 @@
 #define DWARF_REG_FB  0xd3affb /* random number */
 
 #ifdef HAVE_LIBDW_SUPPORT
+#if !defined(__x86_64__) && !defined(__i386__)
 const char *get_arch_regstr(unsigned int n);
+#endif
+
 /**
  * get_dwarf_regstr() - Returns ftrace register string from DWARF regnum.
  * @n: DWARF register number.
@@ -98,7 +101,12 @@ const char *get_arch_regstr(unsigned int n);
  */
 const char *get_dwarf_regstr(unsigned int n, unsigned int machine, unsigned int flags);
 
+int get_x86_regnum(const char *name);
+
+#if !defined(__x86_64__) && !defined(__i386__)
 int get_arch_regnum(const char *name);
+#endif
+
 /*
  * get_dwarf_regnum - Returns DWARF regnum from register name
  * name: architecture register name