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#define SAVE_REGS \ 17 addik r1, r1, -120; \ 18 swi r2, r1, 4; \ 19 swi r3, r1, 8; \ 20 swi r4, r1, 12; \ 21 swi r5, r1, 116; \ 22 swi r6, r1, 16; \ 23 swi r7, r1, 20; \ 24 swi r8, r1, 24; \ 25 swi r9, r1, 28; \ 26 swi r10, r1, 32; \ 27 swi r11, r1, 36; \ 28 swi r12, r1, 40; \ 29 swi r13, r1, 44; \ 30 swi r14, r1, 48; \ 31 swi r16, r1, 52; \ 32 swi r17, r1, 56; \ 33 swi r18, r1, 60; \ 34 swi r19, r1, 64; \ 35 swi r20, r1, 68; \ 36 swi r21, r1, 72; \ 37 swi r22, r1, 76; \ 38 swi r23, r1, 80; \ 39 swi r24, r1, 84; \ 40 swi r25, r1, 88; \ 41 swi r26, r1, 92; \ 42 swi r27, r1, 96; \ 43 swi r28, r1, 100; \ 44 swi r29, r1, 104; \ 45 swi r30, r1, 108; \ 46 swi r31, r1, 112; 47 48#define RESTORE_REGS \ 49 lwi r2, r1, 4; \ 50 lwi r3, r1, 8; \ 51 lwi r4, r1, 12; \ 52 lwi r5, r1, 116; \ 53 lwi r6, r1, 16; \ 54 lwi r7, r1, 20; \ 55 lwi r8, r1, 24; \ 56 lwi r9, r1, 28; \ 57 lwi r10, r1, 32; \ 58 lwi r11, r1, 36; \ 59 lwi r12, r1, 40; \ 60 lwi r13, r1, 44; \ 61 lwi r14, r1, 48; \ 62 lwi r16, r1, 52; \ 63 lwi r17, r1, 56; \ 64 lwi r18, r1, 60; \ 65 lwi r19, r1, 64; \ 66 lwi r20, r1, 68; \ 67 lwi r21, r1, 72; \ 68 lwi r22, r1, 76; \ 69 lwi r23, r1, 80; \ 70 lwi r24, r1, 84; \ 71 lwi r25, r1, 88; \ 72 lwi r26, r1, 92; \ 73 lwi r27, r1, 96; \ 74 lwi r28, r1, 100; \ 75 lwi r29, r1, 104; \ 76 lwi r30, r1, 108; \ 77 lwi r31, r1, 112; \ 78 addik r1, r1, 120; 79 80ENTRY(ftrace_stub) 81 rtsd r15, 8; 82 nop; 83 84ENTRY(_mcount) 85#ifdef CONFIG_DYNAMIC_FTRACE 86ENTRY(ftrace_caller) 87 /* MS: It is just barrier which is removed from C code */ 88 rtsd r15, 8 89 nop 90#endif /* CONFIG_DYNAMIC_FTRACE */ 91 SAVE_REGS 92 swi r15, r1, 0; 93 /* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST begin of checking */ 94 lwi r5, r0, function_trace_stop; 95 bneid r5, end; 96 nop; 97 /* MS: HAVE_FUNCTION_TRACE_MCOUNT_TEST end of checking */ 98#ifdef CONFIG_FUNCTION_GRAPH_TRACER 99#ifndef CONFIG_DYNAMIC_FTRACE 100 lwi r5, r0, ftrace_graph_return; 101 addik r6, r0, ftrace_stub; /* asm implementation */ 102 cmpu r5, r5, r6; /* ftrace_graph_return != ftrace_stub */ 103 beqid r5, end_graph_tracer; 104 nop; 105 106 lwi r6, r0, ftrace_graph_entry; 107 addik r5, r0, ftrace_graph_entry_stub; /* implemented in C */ 108 cmpu r5, r5, r6; /* ftrace_graph_entry != ftrace_graph_entry_stub */ 109 beqid r5, end_graph_tracer; 110 nop; 111#else /* CONFIG_DYNAMIC_FTRACE */ 112NOALIGN_ENTRY(ftrace_call_graph) 113 /* MS: jump over graph function - replaced from C code */ 114 bri end_graph_tracer 115#endif /* CONFIG_DYNAMIC_FTRACE */ 116 addik r5, r1, 120; /* MS: load parent addr */ 117 addik r6, r15, 0; /* MS: load current function addr */ 118 bralid r15, prepare_ftrace_return; 119 nop; 120 /* MS: graph was taken that's why - can jump over function trace */ 121 brid end; 122 nop; 123end_graph_tracer: 124#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ 125#ifndef CONFIG_DYNAMIC_FTRACE 126 /* MS: test function trace if is taken or not */ 127 lwi r20, r0, ftrace_trace_function; 128 addik r6, r0, ftrace_stub; 129 cmpu r5, r20, r6; /* ftrace_trace_function != ftrace_stub */ 130 beqid r5, end; /* MS: not taken -> jump over */ 131 nop; 132#else /* CONFIG_DYNAMIC_FTRACE */ 133NOALIGN_ENTRY(ftrace_call) 134/* instruction for setup imm FUNC_part1, addik r20, r0, FUNC_part2 */ 135 nop 136 nop 137#endif /* CONFIG_DYNAMIC_FTRACE */ 138/* static normal trace */ 139 lwi r6, r1, 120; /* MS: load parent addr */ 140 addik r5, r15, 0; /* MS: load current function addr */ 141 /* MS: here is dependency on previous code */ 142 brald r15, r20; /* MS: jump to ftrace handler */ 143 nop; 144end: 145 lwi r15, r1, 0; 146 RESTORE_REGS 147 148 rtsd r15, 8; /* MS: jump back */ 149 nop; 150 151#ifdef CONFIG_FUNCTION_GRAPH_TRACER 152ENTRY(return_to_handler) 153 nop; /* MS: just barrier for rtsd r15, 8 */ 154 nop; 155 SAVE_REGS 156 swi r15, r1, 0; 157 158 /* MS: find out returning address */ 159 bralid r15, ftrace_return_to_handler; 160 nop; 161 162 /* MS: return value from ftrace_return_to_handler is my returning addr 163 * must be before restore regs because I have to restore r3 content */ 164 addik r15, r3, 0; 165 RESTORE_REGS 166 167 rtsd r15, 8; /* MS: jump back */ 168 nop; 169#endif /* CONFIG_FUNCTION_TRACER */ 170