mcount.S (4066B)
1/* 2 * Low-level ftrace handling 3 * 4 * Copyright (C) 2009 Michal Simek <monstr@monstr.eu> 5 * Copyright (C) 2009 PetaLogix 6 * 7 * This file is subject to the terms and conditions of the GNU General 8 * Public License. See the file COPYING in the main directory of this 9 * archive for more details. 10 */ 11 12#include <linux/linkage.h> 13 14#define NOALIGN_ENTRY(name) .globl name; name: 15 16/* FIXME MS: I think that I don't need to save all regs */ 17#define SAVE_REGS \ 18 addik r1, r1, -120; \ 19 swi r2, r1, 4; \ 20 swi r3, r1, 8; \ 21 swi r4, r1, 12; \ 22 swi r5, r1, 116; \ 23 swi r6, r1, 16; \ 24 swi r7, r1, 20; \ 25 swi r8, r1, 24; \ 26 swi r9, r1, 28; \ 27 swi r10, r1, 32; \ 28 swi r11, r1, 36; \ 29 swi r12, r1, 40; \ 30 swi r13, r1, 44; \ 31 swi r14, r1, 48; \ 32 swi r16, r1, 52; \ 33 swi r17, r1, 56; \ 34 swi r18, r1, 60; \ 35 swi r19, r1, 64; \ 36 swi r20, r1, 68; \ 37 swi r21, r1, 72; \ 38 swi r22, r1, 76; \ 39 swi r23, r1, 80; \ 40 swi r24, r1, 84; \ 41 swi r25, r1, 88; \ 42 swi r26, r1, 92; \ 43 swi r27, r1, 96; \ 44 swi r28, r1, 100; \ 45 swi r29, r1, 104; \ 46 swi r30, r1, 108; \ 47 swi r31, r1, 112; 48 49#define RESTORE_REGS \ 50 lwi r2, r1, 4; \ 51 lwi r3, r1, 8; \ 52 lwi r4, r1, 12; \ 53 lwi r5, r1, 116; \ 54 lwi r6, r1, 16; \ 55 lwi r7, r1, 20; \ 56 lwi r8, r1, 24; \ 57 lwi r9, r1, 28; \ 58 lwi r10, r1, 32; \ 59 lwi r11, r1, 36; \ 60 lwi r12, r1, 40; \ 61 lwi r13, r1, 44; \ 62 lwi r14, r1, 48; \ 63 lwi r16, r1, 52; \ 64 lwi r17, r1, 56; \ 65 lwi r18, r1, 60; \ 66 lwi r19, r1, 64; \ 67 lwi r20, r1, 68; \ 68 lwi r21, r1, 72; \ 69 lwi r22, r1, 76; \ 70 lwi r23, r1, 80; \ 71 lwi r24, r1, 84; \ 72 lwi r25, r1, 88; \ 73 lwi r26, r1, 92; \ 74 lwi r27, r1, 96; \ 75 lwi r28, r1, 100; \ 76 lwi r29, r1, 104; \ 77 lwi r30, r1, 108; \ 78 lwi r31, r1, 112; \ 79 addik r1, r1, 120; 80 81ENTRY(ftrace_stub) 82 rtsd r15, 8; 83 nop; 84 85ENTRY(_mcount) 86#ifdef CONFIG_DYNAMIC_FTRACE 87ENTRY(ftrace_caller) 88 /* MS: It is just barrier which is removed from C code */ 89 rtsd r15, 8 90 nop 91#endif /* CONFIG_DYNAMIC_FTRACE */ 92 SAVE_REGS 93 swi r15, r1, 0; 94#ifdef CONFIG_FUNCTION_GRAPH_TRACER 95#ifndef CONFIG_DYNAMIC_FTRACE 96 lwi r5, r0, ftrace_graph_return; 97 addik r6, r0, ftrace_stub; /* asm implementation */ 98 cmpu r5, r5, r6; /* ftrace_graph_return != ftrace_stub */ 99 beqid r5, end_graph_tracer; 100 nop; 101 102 lwi r6, r0, ftrace_graph_entry; 103 addik r5, r0, ftrace_graph_entry_stub; /* implemented in C */ 104 cmpu r5, r5, r6; /* ftrace_graph_entry != ftrace_graph_entry_stub */ 105 beqid r5, end_graph_tracer; 106 nop; 107#else /* CONFIG_DYNAMIC_FTRACE */ 108NOALIGN_ENTRY(ftrace_call_graph) 109 /* MS: jump over graph function - replaced from C code */ 110 bri end_graph_tracer 111#endif /* CONFIG_DYNAMIC_FTRACE */ 112 addik r5, r1, 120; /* MS: load parent addr */ 113 addik r6, r15, 0; /* MS: load current function addr */ 114 bralid r15, prepare_ftrace_return; 115 nop; 116 /* MS: graph was taken that's why - can jump over function trace */ 117 brid end; 118 nop; 119end_graph_tracer: 120#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 121#ifndef CONFIG_DYNAMIC_FTRACE 122 /* MS: test function trace if is taken or not */ 123 lwi r20, r0, ftrace_trace_function; 124 addik r6, r0, ftrace_stub; 125 cmpu r5, r20, r6; /* ftrace_trace_function != ftrace_stub */ 126 beqid r5, end; /* MS: not taken -> jump over */ 127 nop; 128#else /* CONFIG_DYNAMIC_FTRACE */ 129NOALIGN_ENTRY(ftrace_call) 130/* instruction for setup imm FUNC_part1, addik r20, r0, FUNC_part2 */ 131 nop 132 nop 133#endif /* CONFIG_DYNAMIC_FTRACE */ 134/* static normal trace */ 135 lwi r6, r1, 120; /* MS: load parent addr */ 136 addik r5, r15, -4; /* MS: load current function addr */ 137 /* MS: here is dependency on previous code */ 138 brald r15, r20; /* MS: jump to ftrace handler */ 139 nop; 140end: 141 lwi r15, r1, 0; 142 RESTORE_REGS 143 144 rtsd r15, 8; /* MS: jump back */ 145 nop; 146 147#ifdef CONFIG_FUNCTION_GRAPH_TRACER 148ENTRY(return_to_handler) 149 nop; /* MS: just barrier for rtsd r15, 8 */ 150 nop; 151 SAVE_REGS 152 swi r15, r1, 0; 153 154 /* MS: find out returning address */ 155 bralid r15, ftrace_return_to_handler; 156 nop; 157 158 /* MS: return value from ftrace_return_to_handler is my returning addr 159 * must be before restore regs because I have to restore r3 content */ 160 addik r15, r3, 0; 161 RESTORE_REGS 162 163 rtsd r15, 8; /* MS: jump back */ 164 nop; 165#endif /* CONFIG_FUNCTION_TRACER */