root/arch/sparc/lib/mcount.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com)
   4  *
   5  * This file implements mcount(), which is used to collect profiling data.
   6  * This can also be tweaked for kernel stack overflow detection.
   7  */
   8 
   9 #include <linux/linkage.h>
  10 #include <asm/export.h>
  11 
  12 /*
  13  * This is the main variant and is called by C code.  GCC's -pg option
  14  * automatically instruments every C function with a call to this.
  15  */
  16 
  17         .text
  18         .align          32
  19         .globl          _mcount
  20         .type           _mcount,#function
  21         EXPORT_SYMBOL(_mcount)
  22         .globl          mcount
  23         .type           mcount,#function
  24 _mcount:
  25 mcount:
  26 #ifdef CONFIG_FUNCTION_TRACER
  27 #ifdef CONFIG_DYNAMIC_FTRACE
  28         /* Do nothing, the retl/nop below is all we need.  */
  29 #else
  30         sethi           %hi(ftrace_trace_function), %g1
  31         sethi           %hi(ftrace_stub), %g2
  32         ldx             [%g1 + %lo(ftrace_trace_function)], %g1
  33         or              %g2, %lo(ftrace_stub), %g2
  34         cmp             %g1, %g2
  35         be,pn           %icc, 1f
  36          mov            %i7, %g3
  37         save            %sp, -176, %sp
  38         mov             %g3, %o1
  39         jmpl            %g1, %o7
  40          mov            %i7, %o0
  41         ret
  42          restore
  43         /* not reached */
  44 1:
  45 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  46         sethi           %hi(ftrace_graph_return), %g1
  47         ldx             [%g1 + %lo(ftrace_graph_return)], %g3
  48         cmp             %g2, %g3
  49         bne,pn          %xcc, 5f
  50          sethi          %hi(ftrace_graph_entry_stub), %g2
  51         sethi           %hi(ftrace_graph_entry), %g1
  52         or              %g2, %lo(ftrace_graph_entry_stub), %g2
  53         ldx             [%g1 + %lo(ftrace_graph_entry)], %g1
  54         cmp             %g1, %g2
  55         be,pt           %xcc, 2f
  56          nop
  57 5:      mov             %i7, %g2
  58         mov             %fp, %g3
  59         save            %sp, -176, %sp
  60         mov             %g2, %l0
  61         ba,pt           %xcc, ftrace_graph_caller
  62          mov            %g3, %l1
  63 #endif
  64 2:
  65 #endif
  66 #endif
  67         retl
  68          nop
  69         .size           _mcount,.-_mcount
  70         .size           mcount,.-mcount
  71 
  72 #ifdef CONFIG_FUNCTION_TRACER
  73         .globl          ftrace_stub
  74         .type           ftrace_stub,#function
  75 ftrace_stub:
  76         retl
  77          nop
  78         .size           ftrace_stub,.-ftrace_stub
  79 #ifdef CONFIG_DYNAMIC_FTRACE
  80         .globl          ftrace_caller
  81         .type           ftrace_caller,#function
  82 ftrace_caller:
  83         mov             %i7, %g2
  84         mov             %fp, %g3
  85         save            %sp, -176, %sp
  86         mov             %g2, %o1
  87         mov             %g2, %l0
  88         mov             %g3, %l1
  89         .globl          ftrace_call
  90 ftrace_call:
  91         call            ftrace_stub
  92          mov            %i7, %o0
  93 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  94         .globl          ftrace_graph_call
  95 ftrace_graph_call:
  96         call            ftrace_stub
  97          nop
  98 #endif
  99         ret
 100          restore
 101 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 102         .size           ftrace_graph_call,.-ftrace_graph_call
 103 #endif
 104         .size           ftrace_call,.-ftrace_call
 105         .size           ftrace_caller,.-ftrace_caller
 106 #endif
 107 #endif
 108 
 109 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 110 ENTRY(ftrace_graph_caller)
 111         mov             %l0, %o0
 112         mov             %i7, %o1
 113         call            prepare_ftrace_return
 114          mov            %l1, %o2
 115         ret
 116          restore        %o0, -8, %i7
 117 END(ftrace_graph_caller)
 118 
 119 ENTRY(return_to_handler)
 120         save            %sp, -176, %sp
 121         call            ftrace_return_to_handler
 122          mov            %fp, %o0
 123         jmpl            %o0 + 8, %g0
 124          restore
 125 END(return_to_handler)
 126 #endif