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authorGuo Ren <ren_guo@c-sky.com>2018-12-15 21:04:27 +0800
committerGuo Ren <ren_guo@c-sky.com>2018-12-31 23:17:23 +0800
commitd7950be145c84ca5094c52bc1ad1e7f1893d0f19 (patch)
treec69b59c597f07f36159112ad3afc251feb32455e /arch/csky/abiv2
parent230c77a5e92a29bf21e98ee35e22b0537f61c55b (diff)
downloadlinux-sh-d7950be145c84ca5094c52bc1ad1e7f1893d0f19.tar.gz
csky: ftrace call graph supported.
With csky-gcc -pg -mbacktrace, ftrace call graph supported. Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Diffstat (limited to 'arch/csky/abiv2')
-rw-r--r--arch/csky/abiv2/mcount.S116
1 files changed, 108 insertions, 8 deletions
diff --git a/arch/csky/abiv2/mcount.S b/arch/csky/abiv2/mcount.S
index 73377d5ddd18..c633379956f5 100644
--- a/arch/csky/abiv2/mcount.S
+++ b/arch/csky/abiv2/mcount.S
@@ -2,23 +2,123 @@
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/linkage.h>
+#include <asm/ftrace.h>
-ENTRY (_mcount)
- subi sp, 20
+/*
+ * csky-gcc with -pg will put the following asm after prologue:
+ * push r15
+ * jsri _mcount
+ *
+ * stack layout after mcount_enter in _mcount():
+ *
+ * current sp => 0:+-------+
+ * | a0-a3 | -> must save all argument regs
+ * +16:+-------+
+ * | lr | -> _mcount lr (instrumente function's pc)
+ * +20:+-------+
+ * | fp=r8 | -> instrumented function fp
+ * +24:+-------+
+ * | plr | -> instrumented function lr (parent's pc)
+ * +-------+
+ */
+
+.macro mcount_enter
+ subi sp, 24
stw a0, (sp, 0)
stw a1, (sp, 4)
stw a2, (sp, 8)
stw a3, (sp, 12)
stw lr, (sp, 16)
- mov a1, lr
- ldw a0, (sp, 20)
- jsri csky_mcount
+ stw r8, (sp, 20)
+.endm
+
+.macro mcount_exit
ldw a0, (sp, 0)
ldw a1, (sp, 4)
ldw a2, (sp, 8)
ldw a3, (sp, 12)
ldw t1, (sp, 16)
- ldw lr, (sp, 20)
- addi sp, 24
+ ldw r8, (sp, 20)
+ ldw lr, (sp, 24)
+ addi sp, 28
jmp t1
-END (_mcount)
+.endm
+
+.macro save_return_regs
+ subi sp, 16
+ stw a0, (sp, 0)
+ stw a1, (sp, 4)
+ stw a2, (sp, 8)
+ stw a3, (sp, 12)
+.endm
+
+.macro restore_return_regs
+ mov lr, a0
+ ldw a0, (sp, 0)
+ ldw a1, (sp, 4)
+ ldw a2, (sp, 8)
+ ldw a3, (sp, 12)
+ addi sp, 16
+.endm
+
+ENTRY(ftrace_stub)
+ jmp lr
+END(ftrace_stub)
+
+ENTRY(_mcount)
+ mcount_enter
+
+ /* r26 is link register, only used with jsri translation */
+ lrw r26, ftrace_trace_function
+ ldw r26, (r26, 0)
+ lrw a1, ftrace_stub
+ cmpne r26, a1
+ bf skip_ftrace
+
+ mov a0, lr
+ subi a0, MCOUNT_INSN_SIZE
+ ldw a1, (sp, 24)
+
+ jsr r26
+
+#ifndef CONFIG_FUNCTION_GRAPH_TRACER
+skip_ftrace:
+ mcount_exit
+#else
+skip_ftrace:
+ lrw a0, ftrace_graph_return
+ ldw a0, (a0, 0)
+ lrw a1, ftrace_stub
+ cmpne a0, a1
+ bt ftrace_graph_caller
+
+ lrw a0, ftrace_graph_entry
+ ldw a0, (a0, 0)
+ lrw a1, ftrace_graph_entry_stub
+ cmpne a0, a1
+ bt ftrace_graph_caller
+
+ mcount_exit
+#endif
+END(_mcount)
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ENTRY(ftrace_graph_caller)
+ mov a0, sp
+ addi a0, 24
+ ldw a1, (sp, 16)
+ subi a1, MCOUNT_INSN_SIZE
+ mov a2, r8
+ lrw r26, prepare_ftrace_return
+ jsr r26
+ mcount_exit
+END(ftrace_graph_caller)
+
+ENTRY(return_to_handler)
+ save_return_regs
+ mov a0, r8
+ jsri ftrace_return_to_handler
+ restore_return_regs
+ jmp lr
+END(return_to_handler)
+#endif