[PATCH 2/3] perf tools: Support mips unwinding and dwarf-regs

From: Tiezhu Yang
Date: Tue Dec 29 2020 - 07:57:43 EST


Map perf APIs(perf_reg_name/get_arch_regstr/unwind__arch_reg_id)
with MIPS specific registers.

[ayan@xxxxxxxxxxxx: repick this patch for unwinding userstack
backtrace by perf and libunwind on MIPS based CPU.]

[yangtiezhu@xxxxxxxxxxx: Add sample_reg_masks[] to fix build
error, silence some checkpatch errors and warnings, and also
separate the original patches into two parts (MIPS kernel and
perf tools) to merge easily.]

The original patches:
https://lore.kernel.org/patchwork/patch/1126521/
https://lore.kernel.org/patchwork/patch/1126520/

Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Archer Yan <ayan@xxxxxxxxxxxx>
Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
tools/perf/Makefile.config | 6 ++
tools/perf/arch/mips/Makefile | 4 ++
tools/perf/arch/mips/include/dwarf-regs-table.h | 31 +++++++++
tools/perf/arch/mips/include/perf_regs.h | 84 +++++++++++++++++++++++++
tools/perf/arch/mips/util/Build | 3 +
tools/perf/arch/mips/util/dwarf-regs.c | 38 +++++++++++
tools/perf/arch/mips/util/perf_regs.c | 6 ++
tools/perf/arch/mips/util/unwind-libunwind.c | 22 +++++++
tools/perf/util/dwarf-regs.c | 3 +
9 files changed, 197 insertions(+)
create mode 100644 tools/perf/arch/mips/Makefile
create mode 100644 tools/perf/arch/mips/include/dwarf-regs-table.h
create mode 100644 tools/perf/arch/mips/include/perf_regs.h
create mode 100644 tools/perf/arch/mips/util/Build
create mode 100644 tools/perf/arch/mips/util/dwarf-regs.c
create mode 100644 tools/perf/arch/mips/util/perf_regs.c
create mode 100644 tools/perf/arch/mips/util/unwind-libunwind.c

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index ce8516e..e378add 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -87,6 +87,12 @@ ifeq ($(ARCH),s390)
CFLAGS += -fPIC -I$(OUTPUT)arch/s390/include/generated
endif

+ifeq ($(ARCH),mips)
+ NO_PERF_REGS := 0
+ CFLAGS += -I../../arch/mips/include/uapi -I../../arch/mips/include/generated/uapi
+ LIBUNWIND_LIBS = -lunwind -lunwind-mips
+endif
+
ifeq ($(NO_PERF_REGS),0)
$(call detected,CONFIG_PERF_REGS)
endif
diff --git a/tools/perf/arch/mips/Makefile b/tools/perf/arch/mips/Makefile
new file mode 100644
index 0000000..6e1106f
--- /dev/null
+++ b/tools/perf/arch/mips/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+endif
diff --git a/tools/perf/arch/mips/include/dwarf-regs-table.h b/tools/perf/arch/mips/include/dwarf-regs-table.h
new file mode 100644
index 0000000..5badbcd
--- /dev/null
+++ b/tools/perf/arch/mips/include/dwarf-regs-table.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * dwarf-regs-table.h : Mapping of DWARF debug register numbers into
+ * register names.
+ *
+ * Copyright (C) 2013 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifdef DEFINE_DWARF_REGSTR_TABLE
+#undef REG_DWARFNUM_NAME
+#define REG_DWARFNUM_NAME(reg, idx) [idx] = "$" #reg
+static const char * const mips_regstr_tbl[] = {
+ "$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7", "$8", "$9",
+ "$10", "$11", "$12", "$13", "$14", "$15", "$16", "$17", "$18", "$19",
+ "$20", "$21", "$22", "$23", "$24", "$25", "$26", "$27", "$28", "%29",
+ "$30", "$31",
+ REG_DWARFNUM_NAME(hi, 64),
+ REG_DWARFNUM_NAME(lo, 65),
+};
+#endif
diff --git a/tools/perf/arch/mips/include/perf_regs.h b/tools/perf/arch/mips/include/perf_regs.h
new file mode 100644
index 0000000..7a7908b
--- /dev/null
+++ b/tools/perf/arch/mips/include/perf_regs.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ARCH_PERF_REGS_H
+#define ARCH_PERF_REGS_H
+
+#include <stdlib.h>
+#include <linux/types.h>
+#include <asm/perf_regs.h>
+
+#define PERF_REGS_MAX PERF_REG_MIPS_MAX
+#define PERF_REG_IP PERF_REG_MIPS_PC
+#define PERF_REG_SP PERF_REG_MIPS_R29
+
+#define PERF_REGS_MASK ((1ULL << PERF_REG_MIPS_MAX) - 1)
+
+static inline const char *perf_reg_name(int id)
+{
+ switch (id) {
+ case PERF_REG_MIPS_PC:
+ return "PC";
+ case PERF_REG_MIPS_R1:
+ return "$1";
+ case PERF_REG_MIPS_R2:
+ return "$2";
+ case PERF_REG_MIPS_R3:
+ return "$3";
+ case PERF_REG_MIPS_R4:
+ return "$4";
+ case PERF_REG_MIPS_R5:
+ return "$5";
+ case PERF_REG_MIPS_R6:
+ return "$6";
+ case PERF_REG_MIPS_R7:
+ return "$7";
+ case PERF_REG_MIPS_R8:
+ return "$8";
+ case PERF_REG_MIPS_R9:
+ return "$9";
+ case PERF_REG_MIPS_R10:
+ return "$10";
+ case PERF_REG_MIPS_R11:
+ return "$11";
+ case PERF_REG_MIPS_R12:
+ return "$12";
+ case PERF_REG_MIPS_R13:
+ return "$13";
+ case PERF_REG_MIPS_R14:
+ return "$14";
+ case PERF_REG_MIPS_R15:
+ return "$15";
+ case PERF_REG_MIPS_R16:
+ return "$16";
+ case PERF_REG_MIPS_R17:
+ return "$17";
+ case PERF_REG_MIPS_R18:
+ return "$18";
+ case PERF_REG_MIPS_R19:
+ return "$19";
+ case PERF_REG_MIPS_R20:
+ return "$20";
+ case PERF_REG_MIPS_R21:
+ return "$21";
+ case PERF_REG_MIPS_R22:
+ return "$22";
+ case PERF_REG_MIPS_R23:
+ return "$23";
+ case PERF_REG_MIPS_R24:
+ return "$24";
+ case PERF_REG_MIPS_R25:
+ return "$25";
+ case PERF_REG_MIPS_R28:
+ return "$28";
+ case PERF_REG_MIPS_R29:
+ return "$29";
+ case PERF_REG_MIPS_R30:
+ return "$30";
+ case PERF_REG_MIPS_R31:
+ return "$31";
+ default:
+ break;
+ }
+ return NULL;
+}
+
+#endif /* ARCH_PERF_REGS_H */
diff --git a/tools/perf/arch/mips/util/Build b/tools/perf/arch/mips/util/Build
new file mode 100644
index 0000000..51c8900
--- /dev/null
+++ b/tools/perf/arch/mips/util/Build
@@ -0,0 +1,3 @@
+perf-y += perf_regs.o
+perf-$(CONFIG_DWARF) += dwarf-regs.o
+perf-$(CONFIG_LOCAL_LIBUNWIND) += unwind-libunwind.o
diff --git a/tools/perf/arch/mips/util/dwarf-regs.c b/tools/perf/arch/mips/util/dwarf-regs.c
new file mode 100644
index 0000000..25c13a9
--- /dev/null
+++ b/tools/perf/arch/mips/util/dwarf-regs.c
@@ -0,0 +1,38 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
+ *
+ * Copyright (C) 2013 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <stdio.h>
+#include <dwarf-regs.h>
+
+static const char *mips_gpr_names[32] = {
+ "$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7", "$8", "$9",
+ "$10", "$11", "$12", "$13", "$14", "$15", "$16", "$17", "$18", "$19",
+ "$20", "$21", "$22", "$23", "$24", "$25", "$26", "$27", "$28", "$29",
+ "$30", "$31"
+};
+
+const char *get_arch_regstr(unsigned int n)
+{
+ if (n < 32)
+ return mips_gpr_names[n];
+ if (n == 64)
+ return "hi";
+ if (n == 65)
+ return "lo";
+ return NULL;
+}
diff --git a/tools/perf/arch/mips/util/perf_regs.c b/tools/perf/arch/mips/util/perf_regs.c
new file mode 100644
index 0000000..2864e2e
--- /dev/null
+++ b/tools/perf/arch/mips/util/perf_regs.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "../../util/perf_regs.h"
+
+const struct sample_reg sample_reg_masks[] = {
+ SMPL_REG_END
+};
diff --git a/tools/perf/arch/mips/util/unwind-libunwind.c b/tools/perf/arch/mips/util/unwind-libunwind.c
new file mode 100644
index 0000000..0d8c99c
--- /dev/null
+++ b/tools/perf/arch/mips/util/unwind-libunwind.c
@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <libunwind.h>
+#include "perf_regs.h"
+#include "../../util/unwind.h"
+#include "util/debug.h"
+
+int libunwind__arch_reg_id(int regnum)
+{
+ switch (regnum) {
+ case UNW_MIPS_R1 ... UNW_MIPS_R25:
+ return regnum - UNW_MIPS_R1 + PERF_REG_MIPS_R1;
+ case UNW_MIPS_R28 ... UNW_MIPS_R31:
+ return regnum - UNW_MIPS_R28 + PERF_REG_MIPS_R28;
+ case UNW_MIPS_PC:
+ return PERF_REG_MIPS_PC;
+ default:
+ pr_err("unwind: invalid reg id %d\n", regnum);
+ return -EINVAL;
+ }
+}
diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
index 1b49ece..3fa4486 100644
--- a/tools/perf/util/dwarf-regs.c
+++ b/tools/perf/util/dwarf-regs.c
@@ -24,6 +24,7 @@
#include "../arch/s390/include/dwarf-regs-table.h"
#include "../arch/sparc/include/dwarf-regs-table.h"
#include "../arch/xtensa/include/dwarf-regs-table.h"
+#include "../arch/mips/include/dwarf-regs-table.h"

#define __get_dwarf_regstr(tbl, n) (((n) < ARRAY_SIZE(tbl)) ? (tbl)[(n)] : NULL)

@@ -53,6 +54,8 @@ const char *get_dwarf_regstr(unsigned int n, unsigned int machine)
return __get_dwarf_regstr(sparc_regstr_tbl, n);
case EM_XTENSA:
return __get_dwarf_regstr(xtensa_regstr_tbl, n);
+ case EM_MIPS:
+ return __get_dwarf_regstr(mips_regstr_tbl, n);
default:
pr_err("ELF MACHINE %x is not supported.\n", machine);
}
--
2.1.0