perf dwarf-regs: Add S390 perf to DWARF register number mapping functions

These functions allow the generic initial register state code in
unwind-libdw to be used.

Now the non-generic code in unwind-libdw has no uses remove it.

Signed-off-by: Ian Rogers <[email protected]>
Cc: Aditya Bodkhe <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: Alexandre Ghiti <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Athira Rajeev <[email protected]>
Cc: Chun-Tse Shao <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Dr. David Alan Gilbert <[email protected]>
Cc: Guo Ren <[email protected]>
Cc: Haibo Xu <[email protected]>
Cc: Howard Chu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: John Garry <[email protected]>
Cc: Krzysztof Łopatowski <[email protected]>
Cc: Leo Yan <[email protected]>
Cc: Mark Wielaard <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sergei Trofimovich <[email protected]>
Cc: Shimin Guo <[email protected]>
Cc: Stephen Brennan <[email protected]>
Cc: Thomas Falcon <[email protected]>
Cc: Will Deacon <[email protected]>
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: captain5050

tools/perf/util/dwarf-regs-arch/Build

@@ -4,4 +4,5 @@ perf-util-$(CONFIG_LIBDW) += dwarf-regs-csky.o
 perf-util-$(CONFIG_LIBDW) += dwarf-regs-loongarch.o
 perf-util-$(CONFIG_LIBDW) += dwarf-regs-powerpc.o
 perf-util-$(CONFIG_LIBDW) += dwarf-regs-riscv.o
+perf-util-$(CONFIG_LIBDW) += dwarf-regs-s390.o
 perf-util-$(CONFIG_LIBDW) += dwarf-regs-x86.o

tools/perf/util/dwarf-regs-arch/dwarf-regs-s390.c

@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <errno.h>
+#include <dwarf-regs.h>
+#include "../../../arch/s390/include/uapi/asm/perf_regs.h"
+
+int __get_dwarf_regnum_for_perf_regnum_s390(int perf_regnum)
+{
+	static const int dwarf_s390_regnums[] = {
+		[PERF_REG_S390_R0] = 0,
+		[PERF_REG_S390_R1] = 1,
+		[PERF_REG_S390_R2] = 2,
+		[PERF_REG_S390_R3] = 3,
+		[PERF_REG_S390_R4] = 4,
+		[PERF_REG_S390_R5] = 5,
+		[PERF_REG_S390_R6] = 6,
+		[PERF_REG_S390_R7] = 7,
+		[PERF_REG_S390_R8] = 8,
+		[PERF_REG_S390_R9] = 9,
+		[PERF_REG_S390_R10] = 10,
+		[PERF_REG_S390_R11] = 11,
+		[PERF_REG_S390_R12] = 12,
+		[PERF_REG_S390_R13] = 13,
+		[PERF_REG_S390_R14] = 14,
+		[PERF_REG_S390_R15] = 15,
+		[PERF_REG_S390_FP0] = 16,
+		[PERF_REG_S390_FP1] = 20,
+		[PERF_REG_S390_FP2] = 17,
+		[PERF_REG_S390_FP3] = 21,
+		[PERF_REG_S390_FP4] = 18,
+		[PERF_REG_S390_FP5] = 22,
+		[PERF_REG_S390_FP6] = 19,
+		[PERF_REG_S390_FP7] = 23,
+		[PERF_REG_S390_FP8] = 24,
+		[PERF_REG_S390_FP9] = 28,
+		[PERF_REG_S390_FP10] = 25,
+		[PERF_REG_S390_FP11] = 29,
+		[PERF_REG_S390_FP12] = 26,
+		[PERF_REG_S390_FP13] = 30,
+		[PERF_REG_S390_FP14] = 27,
+		[PERF_REG_S390_FP15] = 31,
+		[PERF_REG_S390_MASK] = 64,
+		[PERF_REG_S390_PC] = 65,
+	};
+
+	if (perf_regnum == 0)
+		return 0;
+
+	if (perf_regnum <  0 || perf_regnum > (int)ARRAY_SIZE(dwarf_s390_regnums) ||
+	    dwarf_s390_regnums[perf_regnum] == 0)
+		return -ENOENT;
+
+	return dwarf_s390_regnums[perf_regnum];
+}

tools/perf/util/dwarf-regs.c

@@ -212,6 +212,9 @@ int get_dwarf_regnum_for_perf_regnum(int perf_regnum, unsigned int machine,
 	case EM_RISCV:
 		reg = __get_dwarf_regnum_for_perf_regnum_riscv(perf_regnum);
 		break;
+	case EM_S390:
+		reg = __get_dwarf_regnum_for_perf_regnum_s390(perf_regnum);
+		break;
 	case EM_LOONGARCH:
 		reg = __get_dwarf_regnum_for_perf_regnum_loongarch(perf_regnum);
 		break;

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

@@ -112,6 +112,7 @@ int __get_dwarf_regnum_for_perf_regnum_csky(int perf_regnum, unsigned int flags)
 int __get_dwarf_regnum_for_perf_regnum_loongarch(int perf_regnum);
 int __get_dwarf_regnum_for_perf_regnum_powerpc(int perf_regnum);
 int __get_dwarf_regnum_for_perf_regnum_riscv(int perf_regnum);
+int __get_dwarf_regnum_for_perf_regnum_s390(int perf_regnum);
 
 /*
  * get_dwarf_regnum - Returns DWARF regnum from register name

tools/perf/util/unwind-libdw-arch/Build

@@ -226,7 +226,7 @@ static bool memory_read(Dwfl *dwfl __maybe_unused, Dwarf_Addr addr, Dwarf_Word *
 	return true;
 }
 
-static bool libdw_set_initial_registers_generic(Dwfl_Thread *thread, void *arg)
+static bool libdw_set_initial_registers(Dwfl_Thread *thread, void *arg)
 {
 	struct unwind_info *ui = arg;
 	struct regs_dump *user_regs = perf_sample__user_regs(ui->sample);
@@ -279,29 +279,12 @@ static bool libdw_set_initial_registers_generic(Dwfl_Thread *thread, void *arg)
 	return ret;
 }
 
-#define DEFINE_DWFL_THREAD_CALLBACKS(arch)                           \
-static const Dwfl_Thread_Callbacks callbacks_##arch = {              \
-	.next_thread           = next_thread,                        \
-	.memory_read           = memory_read,                        \
-	.set_initial_registers = libdw_set_initial_registers_##arch, \
-}
-
-static const Dwfl_Thread_Callbacks callbacks_generic = {
+static const Dwfl_Thread_Callbacks callbacks = {
 	.next_thread           = next_thread,
 	.memory_read           = memory_read,
-	.set_initial_registers = libdw_set_initial_registers_generic,
+	.set_initial_registers = libdw_set_initial_registers,
 };
 
-DEFINE_DWFL_THREAD_CALLBACKS(s390);
-
-static const Dwfl_Thread_Callbacks *get_thread_callbacks(const char *arch)
-{
-	if (!strcmp(arch, "s390"))
-		return &callbacks_s390;
-
-	return &callbacks_generic;
-}
-
 static int
 frame_callback(Dwfl_Frame *state, void *arg)
 {
@@ -349,10 +332,8 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
 		.e_machine	= e_machine,
 		.best_effort    = best_effort
 	};
-	const char *arch = perf_env__arch(machine->env);
 	Dwarf_Word ip;
 	int err = -EINVAL, i;
-	const Dwfl_Thread_Callbacks *callbacks;
 
 	if (!data->user_regs || !data->user_regs->regs)
 		return -EINVAL;
@@ -375,11 +356,7 @@ int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
 	if (err)
 		goto out;
 
-	callbacks = get_thread_callbacks(arch);
-	if (!callbacks)
-		goto out;
-
-	err = !dwfl_attach_state(ui->dwfl, /*elf=*/NULL, thread__tid(thread), callbacks, ui);
+	err = !dwfl_attach_state(ui->dwfl, /*elf=*/NULL, thread__tid(thread), &callbacks, ui);
 	if (err)
 		goto out;
 

tools/perf/util/unwind-libdw-arch/unwind-libdw-s390.c

@@ -10,7 +10,6 @@ struct perf_sample;
 struct thread;
 
 bool libdw_set_initial_registers_mips(Dwfl_Thread *thread, void *arg);
-bool libdw_set_initial_registers_s390(Dwfl_Thread *thread, void *arg);
 
 struct unwind_info {
 	Dwfl			*dwfl;