sparc/lib/mcount.S

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
0004  *
0005  * This file implements mcount(), which is used to collect profiling data.
0006  * This can also be tweaked for kernel stack overflow detection.
0007  */
0008
0009 #include <linux/linkage.h>
0010 #include <asm/export.h>
0011
0012 /*
0013  * This is the main variant and is called by C code.  GCC's -pg option
0014  * automatically instruments every C function with a call to this.
0015  */
0016
0017     .text
0018     .align      32
0019     .globl      _mcount
0020     .type       _mcount,#function
0021     EXPORT_SYMBOL(_mcount)
0022     .globl      mcount
0023     .type       mcount,#function
0024 _mcount:
0025 mcount:
0026 #ifdef CONFIG_FUNCTION_TRACER
0027 #ifdef CONFIG_DYNAMIC_FTRACE
0028     /* Do nothing, the retl/nop below is all we need.  */
0029 #else
0030     sethi       %hi(ftrace_trace_function), %g1
0031     sethi       %hi(ftrace_stub), %g2
0032     ldx     [%g1 + %lo(ftrace_trace_function)], %g1
0033     or      %g2, %lo(ftrace_stub), %g2
0034     cmp     %g1, %g2
0035     be,pn       %icc, 1f
0036      mov        %i7, %g3
0037     save        %sp, -176, %sp
0038     mov     %g3, %o1
0039     jmpl        %g1, %o7
0040      mov        %i7, %o0
0041     ret
0042      restore
0043     /* not reached */
0044 1:
0045 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
0046     sethi       %hi(ftrace_graph_return), %g1
0047     ldx     [%g1 + %lo(ftrace_graph_return)], %g3
0048     cmp     %g2, %g3
0049     bne,pn      %xcc, 5f
0050      sethi      %hi(ftrace_graph_entry_stub), %g2
0051     sethi       %hi(ftrace_graph_entry), %g1
0052     or      %g2, %lo(ftrace_graph_entry_stub), %g2
0053     ldx     [%g1 + %lo(ftrace_graph_entry)], %g1
0054     cmp     %g1, %g2
0055     be,pt       %xcc, 2f
0056      nop
0057 5:  mov     %i7, %g2
0058     mov     %fp, %g3
0059     save        %sp, -176, %sp
0060     mov     %g2, %l0
0061     ba,pt       %xcc, ftrace_graph_caller
0062      mov        %g3, %l1
0063 #endif
0064 2:
0065 #endif
0066 #endif
0067     retl
0068      nop
0069     .size       _mcount,.-_mcount
0070     .size       mcount,.-mcount
0071
0072 #ifdef CONFIG_FUNCTION_TRACER
0073     .globl      ftrace_stub
0074     .type       ftrace_stub,#function
0075 ftrace_stub:
0076     retl
0077      nop
0078     .size       ftrace_stub,.-ftrace_stub
0079 #ifdef CONFIG_DYNAMIC_FTRACE
0080     .globl      ftrace_caller
0081     .type       ftrace_caller,#function
0082 ftrace_caller:
0083     mov     %i7, %g2
0084     mov     %fp, %g3
0085     save        %sp, -176, %sp
0086     mov     %g2, %o1
0087     mov     %g2, %l0
0088     mov     %g3, %l1
0089     .globl      ftrace_call
0090 ftrace_call:
0091     call        ftrace_stub
0092      mov        %i7, %o0
0093 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
0094     .globl      ftrace_graph_call
0095 ftrace_graph_call:
0096     call        ftrace_stub
0097      nop
0098 #endif
0099     ret
0100      restore
0101 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
0102     .size       ftrace_graph_call,.-ftrace_graph_call
0103 #endif
0104     .size       ftrace_call,.-ftrace_call
0105     .size       ftrace_caller,.-ftrace_caller
0106 #endif
0107 #endif
0108
0109 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
0110 ENTRY(ftrace_graph_caller)
0111     mov     %l0, %o0
0112     mov     %i7, %o1
0113     call        prepare_ftrace_return
0114      mov        %l1, %o2
0115     ret
0116      restore    %o0, -8, %i7
0117 END(ftrace_graph_caller)
0118
0119 ENTRY(return_to_handler)
0120     save        %sp, -176, %sp
0121     call        ftrace_return_to_handler
0122      mov        %fp, %o0
0123     jmpl        %o0 + 8, %g0
0124      restore
0125 END(return_to_handler)
0126 #endif