Re: [QUESTION] support perf record --call-graph dwarf for mips
From: Arnaldo Carvalho de Melo
Date: Wed Dec 16 2020 - 10:16:59 EST
Em Wed, Dec 16, 2020 at 11:30:47AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Wed, Dec 16, 2020 at 07:14:02PM +0800, Jiaxun Yang escreveu:
> >
> >
> > 在 2020/12/16 下午6:05, Tiezhu Yang 写道:
> > > Hi,
> > >
> > > In the current upstream mainline kernel, perf record --call-graph dwarf
> > > is not supported for architecture mips64. I find the following related
> > > patches about this feature by David Daney <david.daney@xxxxxxxxxx> and
> > > Archer Yan <ayan@xxxxxxxxxxxx> in Sep 2019.
>
> > AFAIK ddaney left Cavium at 2018 and Wave Computing Shanghai is defuncted...
>
> > Feel free to take over if you like, there is no licenses issue, just
> > remember to credit
> > others properly.
>
> Ralf, can you take a look at the kernel part? The user space part seems
> ok.
I take that back, but made some progress in getting that old patch
closer to what we have now in tools/perf/, see below.
Someone with a mips system should try to refresh the kernel bits and
then see if the patch below works.
- Arnaldo
commit e59de40addb092d7167fa1dd7c6640d0fab41ede
Author: David Daney <david.daney@xxxxxxxxxx>
Date: Wed Sep 11 08:26:37 2019 +0000
perf mips: Support mips unwinding and dwarf-regs.
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.]
Committer notes:
Some header fixups, replace CONFIG_LIBUNWIND with CONFIG_LOCAL_LIBUNWIND
to cope with:
9d8e14d306ef2f5d ("perf unwind: Separate local/remote libunwind config")
Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20190911082548.31546-1-ayan@xxxxxxxxxxxx
Signed-off-by: Archer Yan <ayan@xxxxxxxxxxxx>
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
diff --git a/tools/perf/arch/mips/Makefile b/tools/perf/arch/mips/Makefile
new file mode 100644
index 0000000000000000..6e1106fab26e4015
--- /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/perf_regs.h b/tools/perf/arch/mips/include/perf_regs.h
new file mode 100644
index 0000000000000000..36a28bc1734787ce
--- /dev/null
+++ b/tools/perf/arch/mips/include/perf_regs.h
@@ -0,0 +1,83 @@
+/* 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_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 "$31";
+ default:
+ break;
+ }
+ return NULL;
+}
+
+#endif /* ARCH_PERF_REGS_H */
diff --git a/tools/perf/arch/mips/util/Build b/tools/perf/arch/mips/util/Build
new file mode 100644
index 0000000000000000..7b0c0457154a22c5
--- /dev/null
+++ b/tools/perf/arch/mips/util/Build
@@ -0,0 +1,2 @@
+perf-$(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 0000000000000000..165e0179ea11d9b2
--- /dev/null
+++ b/tools/perf/arch/mips/util/dwarf-regs.c
@@ -0,0 +1,37 @@
+/*
+ * 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 <libio.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/unwind-libunwind.c b/tools/perf/arch/mips/util/unwind-libunwind.c
new file mode 100644
index 0000000000000000..7af25427943f451a
--- /dev/null
+++ b/tools/perf/arch/mips/util/unwind-libunwind.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <errno.h>
+#include <libunwind.h>
+#include "perf_regs.h"
+#include "../../util/unwind.h"
+
+int unwind__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;
+ }
+}