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14#include <asm/cacheflush.h>
15#include <linux/ftrace.h>
16
17#ifdef CONFIG_FUNCTION_GRAPH_TRACER
18
19
20
21
22void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
23{
24 unsigned long old;
25 int faulted, err;
26 struct ftrace_graph_ent trace;
27 unsigned long return_hooker = (unsigned long)
28 &return_to_handler;
29
30 if (unlikely(atomic_read(¤t->tracing_graph_pause)))
31 return;
32
33
34
35
36
37
38 asm volatile(" 1: lwi %0, %2, 0; \
39 2: swi %3, %2, 0; \
40 addik %1, r0, 0; \
41 3: \
42 .section .fixup, \"ax\"; \
43 4: brid 3b; \
44 addik %1, r0, 1; \
45 .previous; \
46 .section __ex_table,\"a\"; \
47 .word 1b,4b; \
48 .word 2b,4b; \
49 .previous;" \
50 : "=&r" (old), "=r" (faulted)
51 : "r" (parent), "r" (return_hooker)
52 );
53
54 if (unlikely(faulted)) {
55 ftrace_graph_stop();
56 WARN_ON(1);
57 return;
58 }
59
60 err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0);
61 if (err == -EBUSY) {
62 *parent = old;
63 return;
64 }
65
66 trace.func = self_addr;
67
68 if (!ftrace_graph_entry(&trace)) {
69 current->curr_ret_stack--;
70 *parent = old;
71 }
72}
73#endif
74
75#ifdef CONFIG_DYNAMIC_FTRACE
76
77static int ftrace_modify_code(unsigned long addr, unsigned int value)
78{
79 int faulted = 0;
80
81 __asm__ __volatile__(" 1: swi %2, %1, 0; \
82 addik %0, r0, 0; \
83 2: \
84 .section .fixup, \"ax\"; \
85 3: brid 2b; \
86 addik %0, r0, 1; \
87 .previous; \
88 .section __ex_table,\"a\"; \
89 .word 1b,3b; \
90 .previous;" \
91 : "=r" (faulted)
92 : "r" (addr), "r" (value)
93 );
94
95 if (unlikely(faulted))
96 return -EFAULT;
97
98 return 0;
99}
100
101#define MICROBLAZE_NOP 0x80000000
102#define MICROBLAZE_BRI 0xb800000C
103
104static unsigned int recorded;
105static unsigned int imm;
106
107
108#undef USE_FTRACE_NOP
109
110#ifdef USE_FTRACE_NOP
111static unsigned int bralid;
112#endif
113
114int ftrace_make_nop(struct module *mod,
115 struct dyn_ftrace *rec, unsigned long addr)
116{
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131
132
133 int ret = 0;
134
135 if (recorded == 0) {
136 recorded = 1;
137 imm = *(unsigned int *)rec->ip;
138 pr_debug("%s: imm:0x%x\n", __func__, imm);
139#ifdef USE_FTRACE_NOP
140 bralid = *(unsigned int *)(rec->ip + 4);
141 pr_debug("%s: bralid 0x%x\n", __func__, bralid);
142#endif
143 }
144
145#ifdef USE_FTRACE_NOP
146 ret = ftrace_modify_code(rec->ip, MICROBLAZE_NOP);
147 ret += ftrace_modify_code(rec->ip + 4, MICROBLAZE_NOP);
148#else
149 ret = ftrace_modify_code(rec->ip, MICROBLAZE_BRI);
150#endif
151 return ret;
152}
153
154
155int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
156{
157 int ret;
158 pr_debug("%s: addr:0x%x, rec->ip: 0x%x, imm:0x%x\n",
159 __func__, (unsigned int)addr, (unsigned int)rec->ip, imm);
160 ret = ftrace_modify_code(rec->ip, imm);
161#ifdef USE_FTRACE_NOP
162 pr_debug("%s: bralid:0x%x\n", __func__, bralid);
163 ret += ftrace_modify_code(rec->ip + 4, bralid);
164#endif
165 return ret;
166}
167
168int __init ftrace_dyn_arch_init(void *data)
169{
170
171 *(unsigned long *)data = 0;
172
173 return 0;
174}
175
176int ftrace_update_ftrace_func(ftrace_func_t func)
177{
178 unsigned long ip = (unsigned long)(&ftrace_call);
179 unsigned int upper = (unsigned int)func;
180 unsigned int lower = (unsigned int)func;
181 int ret = 0;
182
183
184 upper = 0xb0000000 + (upper >> 16);
185 lower = 0x32800000 + (lower & 0xFFFF);
186
187 pr_debug("%s: func=0x%x, ip=0x%x, upper=0x%x, lower=0x%x\n",
188 __func__, (unsigned int)func, (unsigned int)ip, upper, lower);
189
190
191 ret = ftrace_modify_code(ip, upper);
192 ret += ftrace_modify_code(ip + 4, lower);
193
194
195 ret += ftrace_modify_code((unsigned long)&ftrace_caller,
196 MICROBLAZE_NOP);
197
198
199 flush_icache();
200 return ret;
201}
202
203#ifdef CONFIG_FUNCTION_GRAPH_TRACER
204unsigned int old_jump;
205
206int ftrace_enable_ftrace_graph_caller(void)
207{
208 unsigned int ret;
209 unsigned long ip = (unsigned long)(&ftrace_call_graph);
210
211 old_jump = *(unsigned int *)ip;
212 ret = ftrace_modify_code(ip, MICROBLAZE_NOP);
213 flush_icache();
214
215 pr_debug("%s: Replace instruction: 0x%x\n", __func__, old_jump);
216 return ret;
217}
218
219int ftrace_disable_ftrace_graph_caller(void)
220{
221 unsigned int ret;
222 unsigned long ip = (unsigned long)(&ftrace_call_graph);
223
224 ret = ftrace_modify_code(ip, old_jump);
225 flush_icache();
226
227 pr_debug("%s\n", __func__);
228 return ret;
229}
230#endif
231#endif
232