[PATCH v1 15/23] perf dwarf-regs: Add csky perf to dwarf register number mapping functions

Ian Rogers
2026-01-17T05:29:47Z

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

Signed-off-by: Ian Rogers <irogers@google.com>
---
.../util/dwarf-regs-arch/dwarf-regs-csky.c | 58 ++++++++++++++
tools/perf/util/dwarf-regs.c | 3 +
tools/perf/util/include/dwarf-regs.h | 2 +
tools/perf/util/unwind-libdw-arch/Build | 1 -
.../unwind-libdw-arch/unwind-libdw-csky.c | 78 -------------------
tools/perf/util/unwind-libdw.c | 5 +-
tools/perf/util/unwind-libdw.h | 1 -
7 files changed, 64 insertions(+), 84 deletions(-)
delete mode 100644 tools/perf/util/unwind-libdw-arch/unwind-libdw-csky.c

diff --git a/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c b/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c
index 86394ed46397..cb44b774f8d9 100644
--- a/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c
+++ b/tools/perf/util/dwarf-regs-arch/dwarf-regs-csky.c
@@ -5,6 +5,10 @@
#include <errno.h>
#include <stddef.h>
#include <dwarf-regs.h>
+// Ensure the V2 perf reg definitions are included.
+#undef __CSKYABIV2__
+#define __CSKYABIV2__ 1
+#include "../../../arch/csky/include/uapi/asm/perf_regs.h"

#define CSKY_ABIV2_MAX_REGS 73
static const char * const csky_dwarf_regs_table_abiv2[CSKY_ABIV2_MAX_REGS] = {
@@ -66,3 +70,57 @@ int __get_csky_regnum(const char *name, unsigned int flags)

return __get_dwarf_regnum(csky_dwarf_regs_table_abiv1, CSKY_ABIV1_MAX_REGS, name);
}
+
+int __get_dwarf_regnum_for_perf_regnum_csky(int perf_regnum, unsigned int flags)
+{
+ static const int dwarf_csky_regnums[][2] = {
+ [PERF_REG_CSKY_TLS] = {-ENOENT, 31},
+ [PERF_REG_CSKY_LR] = {15, 15},
+ [PERF_REG_CSKY_PC] = {-ENOENT, 32},
+ /* TODO: PERF_REG_CSKY_SR */
+ [PERF_REG_CSKY_SP] = {0, 14},
+ /* TODO: PERF_REG_CSKY_ORIG_A0 */
+ [PERF_REG_CSKY_A0] = {2, 0},
+ [PERF_REG_CSKY_A1] = {3, 1},
+ [PERF_REG_CSKY_A2] = {4, 2},
+ [PERF_REG_CSKY_A3] = {5, 3},
+ [PERF_REG_CSKY_REGS0] = {6, 4},
+ [PERF_REG_CSKY_REGS1] = {7, 5},
+ [PERF_REG_CSKY_REGS2] = {8, 6},
+ [PERF_REG_CSKY_REGS3] = {9, 7},
+ [PERF_REG_CSKY_REGS4] = {10, 8},
+ [PERF_REG_CSKY_REGS5] = {11, 9},
+ [PERF_REG_CSKY_REGS6] = {12, 10},
+ [PERF_REG_CSKY_REGS7] = {13, 11},
+ [PERF_REG_CSKY_REGS8] = {14, 12},
+ [PERF_REG_CSKY_REGS9] = {1, 13},
+ [PERF_REG_CSKY_EXREGS0] = {-ENOENT, 16},
+ [PERF_REG_CSKY_EXREGS1] = {-ENOENT, 17},
+ [PERF_REG_CSKY_EXREGS2] = {-ENOENT, 18},
+ [PERF_REG_CSKY_EXREGS3] = {-ENOENT, 19},
+ [PERF_REG_CSKY_EXREGS4] = {-ENOENT, 20},
+ [PERF_REG_CSKY_EXREGS5] = {-ENOENT, 21},
+ [PERF_REG_CSKY_EXREGS6] = {-ENOENT, 22},
+ [PERF_REG_CSKY_EXREGS7] = {-ENOENT, 23},
+ [PERF_REG_CSKY_EXREGS8] = {-ENOENT, 24},
+ [PERF_REG_CSKY_EXREGS9] = {-ENOENT, 25},
+ [PERF_REG_CSKY_EXREGS10] = {-ENOENT, 26},
+ [PERF_REG_CSKY_EXREGS11] = {-ENOENT, 27},
+ [PERF_REG_CSKY_EXREGS12] = {-ENOENT, 28},
+ [PERF_REG_CSKY_EXREGS13] = {-ENOENT, 29},
+ [PERF_REG_CSKY_EXREGS14] = {-ENOENT, 30},
+ /* TODO: PERF_REG_CSKY_HI */
+ /* TODO: PERF_REG_CSKY_LO */
+ /* TODO: PERF_REG_CSKY_DCSR */
+ };
+ int idx = 0;
+
+ if (flags & EF_CSKY_ABIV2)
+ idx++;
+
+ if (perf_regnum < 0 || perf_regnum > (int)ARRAY_SIZE(dwarf_csky_regnums) ||
+ dwarf_csky_regnums[perf_regnum][idx] == 0)
+ return -ENOENT;
+
+ return dwarf_csky_regnums[perf_regnum][idx];
+}
diff --git a/tools/perf/util/dwarf-regs.c b/tools/perf/util/dwarf-regs.c
index c472ec5e4d1a..7fa0930fd298 100644
--- a/tools/perf/util/dwarf-regs.c
+++ b/tools/perf/util/dwarf-regs.c
@@ -202,6 +202,9 @@ int get_dwarf_regnum_for_perf_regnum(int perf_regnum, unsigned int machine,
case EM_AARCH64:
reg = __get_dwarf_regnum_for_perf_regnum_arm64(perf_regnum);
break;
+ case EM_CSKY:
+ reg = __get_dwarf_regnum_for_perf_regnum_csky(perf_regnum, flags);
+ break;
default:
pr_err("ELF MACHINE %x is not supported.\n", machine);
return -ENOENT;
diff --git a/tools/perf/util/include/dwarf-regs.h b/tools/perf/util/include/dwarf-regs.h
index a52df8d1b138..7780bc07e70e 100644
--- a/tools/perf/util/include/dwarf-regs.h
+++ b/tools/perf/util/include/dwarf-regs.h
@@ -108,6 +108,8 @@ int __get_dwarf_regnum_for_perf_regnum_x86_64(int perf_regnum);
int __get_dwarf_regnum_for_perf_regnum_arm(int perf_regnum);
int __get_dwarf_regnum_for_perf_regnum_arm64(int perf_regnum);

+int __get_dwarf_regnum_for_perf_regnum_csky(int perf_regnum, unsigned int flags);
+
/*
* get_dwarf_regnum - Returns DWARF regnum from register name
* name: architecture register name
diff --git a/tools/perf/util/unwind-libdw-arch/Build b/tools/perf/util/unwind-libdw-arch/Build
index 79c3bbdc2dee..5fa1754fca8d 100644
--- a/tools/perf/util/unwind-libdw-arch/Build
+++ b/tools/perf/util/unwind-libdw-arch/Build
@@ -1,4 +1,3 @@
-perf-util-y += unwind-libdw-csky.o
perf-util-y += unwind-libdw-loongarch.o
perf-util-y += unwind-libdw-powerpc.o
perf-util-y += unwind-libdw-riscv.o
diff --git a/tools/perf/util/unwind-libdw-arch/unwind-libdw-csky.c b/tools/perf/util/unwind-libdw-arch/unwind-libdw-csky.c
deleted file mode 100644
index 2556d034c32a..000000000000
--- a/tools/perf/util/unwind-libdw-arch/unwind-libdw-csky.c
+++ /dev/null
@@ -1,78 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-// Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
-
-#include <elfutils/libdwfl.h>
-#include "../arch/csky/include/uapi/asm/perf_regs.h"
-#include "util/unwind-libdw.h"
-#include "util/perf_regs.h"
-#include "util/sample.h"
-
-bool libdw_set_initial_registers_csky(Dwfl_Thread *thread, void *arg)
-{
- struct unwind_info *ui = arg;
- struct regs_dump *user_regs = perf_sample__user_regs(ui->sample);
- Dwarf_Word dwarf_regs[PERF_REG_CSKY_MAX];
-
-#define REG(r) ({ \
- Dwarf_Word val = 0; \
- perf_reg_value(&val, user_regs, PERF_REG_CSKY_##r); \
- val; \
-})
-
-#if defined(__CSKYABIV2__)
- dwarf_regs[0] = REG(A0);
- dwarf_regs[1] = REG(A1);
- dwarf_regs[2] = REG(A2);
- dwarf_regs[3] = REG(A3);
- dwarf_regs[4] = REG(REGS0);
- dwarf_regs[5] = REG(REGS1);
- dwarf_regs[6] = REG(REGS2);
- dwarf_regs[7] = REG(REGS3);
- dwarf_regs[8] = REG(REGS4);
- dwarf_regs[9] = REG(REGS5);
- dwarf_regs[10] = REG(REGS6);
- dwarf_regs[11] = REG(REGS7);
- dwarf_regs[12] = REG(REGS8);
- dwarf_regs[13] = REG(REGS9);
- dwarf_regs[14] = REG(SP);
- dwarf_regs[15] = REG(LR);
- dwarf_regs[16] = REG(EXREGS0);
- dwarf_regs[17] = REG(EXREGS1);
- dwarf_regs[18] = REG(EXREGS2);
- dwarf_regs[19] = REG(EXREGS3);
- dwarf_regs[20] = REG(EXREGS4);
- dwarf_regs[21] = REG(EXREGS5);
- dwarf_regs[22] = REG(EXREGS6);
- dwarf_regs[23] = REG(EXREGS7);
- dwarf_regs[24] = REG(EXREGS8);
- dwarf_regs[25] = REG(EXREGS9);
- dwarf_regs[26] = REG(EXREGS10);
- dwarf_regs[27] = REG(EXREGS11);
- dwarf_regs[28] = REG(EXREGS12);
- dwarf_regs[29] = REG(EXREGS13);
- dwarf_regs[30] = REG(EXREGS14);
- dwarf_regs[31] = REG(TLS);
- dwarf_regs[32] = REG(PC);
-#else
- dwarf_regs[0] = REG(SP);
- dwarf_regs[1] = REG(REGS9);
- dwarf_regs[2] = REG(A0);
- dwarf_regs[3] = REG(A1);
- dwarf_regs[4] = REG(A2);
- dwarf_regs[5] = REG(A3);
- dwarf_regs[6] = REG(REGS0);
- dwarf_regs[7] = REG(REGS1);
- dwarf_regs[8] = REG(REGS2);
- dwarf_regs[9] = REG(REGS3);
- dwarf_regs[10] = REG(REGS4);
- dwarf_regs[11] = REG(REGS5);
- dwarf_regs[12] = REG(REGS6);
- dwarf_regs[13] = REG(REGS7);
- dwarf_regs[14] = REG(REGS8);
- dwarf_regs[15] = REG(LR);
-#endif
- dwfl_thread_state_register_pc(thread, REG(PC));
-
- return dwfl_thread_state_registers(thread, 0, PERF_REG_CSKY_MAX,
- dwarf_regs);
-}
diff --git a/tools/perf/util/unwind-libdw.c b/tools/perf/util/unwind-libdw.c
index 8f291f9f9469..a193163da707 100644
--- a/tools/perf/util/unwind-libdw.c
+++ b/tools/perf/util/unwind-libdw.c
@@ -292,7 +292,6 @@ static const Dwfl_Thread_Callbacks callbacks_generic = {
.set_initial_registers = libdw_set_initial_registers_generic,
};

-DEFINE_DWFL_THREAD_CALLBACKS(csky);
DEFINE_DWFL_THREAD_CALLBACKS(loongarch);
DEFINE_DWFL_THREAD_CALLBACKS(powerpc);
DEFINE_DWFL_THREAD_CALLBACKS(riscv);
@@ -300,9 +299,7 @@ DEFINE_DWFL_THREAD_CALLBACKS(s390);

static const Dwfl_Thread_Callbacks *get_thread_callbacks(const char *arch)
{
- if (!strcmp(arch, "csky"))
- return &callbacks_csky;
- else if (!strcmp(arch, "loongarch"))
+ if (!strcmp(arch, "loongarch"))
return &callbacks_loongarch;
else if (!strcmp(arch, "powerpc"))
return &callbacks_powerpc;
diff --git a/tools/perf/util/unwind-libdw.h b/tools/perf/util/unwind-libdw.h
index fe3ae2a768ad..ee56f1e827e5 100644
--- a/tools/perf/util/unwind-libdw.h
+++ b/tools/perf/util/unwind-libdw.h
@@ -9,7 +9,6 @@ struct machine;
struct perf_sample;
struct thread;

-bool libdw_set_initial_registers_csky(Dwfl_Thread *thread, void *arg);
bool libdw_set_initial_registers_loongarch(Dwfl_Thread *thread, void *arg);
bool libdw_set_initial_registers_mips(Dwfl_Thread *thread, void *arg);
bool libdw_set_initial_registers_powerpc(Dwfl_Thread *thread, void *arg);
--
2.52.0.457.g6b5491de43-goog