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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 flush_dcache_range((u32)parent, (u32)parent + 4);
55 flush_icache_range((u32)parent, (u32)parent + 4);
56
57 if (unlikely(faulted)) {
58 ftrace_graph_stop();
59 WARN_ON(1);
60 return;
61 }
62
63 err = ftrace_push_return_trace(old, self_addr, &trace.depth, 0);
64 if (err == -EBUSY) {
65 *parent = old;
66 return;
67 }
68
69 trace.func = self_addr;
70
71 if (!ftrace_graph_entry(&trace)) {
72 current->curr_ret_stack--;
73 *parent = old;
74 }
75}
76#endif
77
78#ifdef CONFIG_DYNAMIC_FTRACE
79
80static int ftrace_modify_code(unsigned long addr, unsigned int value)
81{
82 int faulted = 0;
83
84 __asm__ __volatile__(" 1: swi %2, %1, 0; \
85 addik %0, r0, 0; \
86 2: \
87 .section .fixup, \"ax\"; \
88 3: brid 2b; \
89 addik %0, r0, 1; \
90 .previous; \
91 .section __ex_table,\"a\"; \
92 .word 1b,3b; \
93 .previous;" \
94 : "=r" (faulted)
95 : "r" (addr), "r" (value)
96 );
97
98 if (unlikely(faulted))
99 return -EFAULT;
100
101 flush_dcache_range(addr, addr + 4);
102 flush_icache_range(addr, addr + 4);
103
104 return 0;
105}
106
107#define MICROBLAZE_NOP 0x80000000
108#define MICROBLAZE_BRI 0xb800000C
109
110static unsigned int recorded;
111static unsigned int imm;
112
113
114#undef USE_FTRACE_NOP
115
116#ifdef USE_FTRACE_NOP
117static unsigned int bralid;
118#endif
119
120int ftrace_make_nop(struct module *mod,
121 struct dyn_ftrace *rec, unsigned long addr)
122{
123
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135
136
137
138
139 int ret = 0;
140
141 if (recorded == 0) {
142 recorded = 1;
143 imm = *(unsigned int *)rec->ip;
144 pr_debug("%s: imm:0x%x\n", __func__, imm);
145#ifdef USE_FTRACE_NOP
146 bralid = *(unsigned int *)(rec->ip + 4);
147 pr_debug("%s: bralid 0x%x\n", __func__, bralid);
148#endif
149 }
150
151#ifdef USE_FTRACE_NOP
152 ret = ftrace_modify_code(rec->ip, MICROBLAZE_NOP);
153 ret += ftrace_modify_code(rec->ip + 4, MICROBLAZE_NOP);
154#else
155 ret = ftrace_modify_code(rec->ip, MICROBLAZE_BRI);
156#endif
157 return ret;
158}
159
160
161int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
162{
163 int ret;
164 pr_debug("%s: addr:0x%x, rec->ip: 0x%x, imm:0x%x\n",
165 __func__, (unsigned int)addr, (unsigned int)rec->ip, imm);
166 ret = ftrace_modify_code(rec->ip, imm);
167#ifdef USE_FTRACE_NOP
168 pr_debug("%s: bralid:0x%x\n", __func__, bralid);
169 ret += ftrace_modify_code(rec->ip + 4, bralid);
170#endif
171 return ret;
172}
173
174int __init ftrace_dyn_arch_init(void *data)
175{
176
177 *(unsigned long *)data = 0;
178
179 return 0;
180}
181
182int ftrace_update_ftrace_func(ftrace_func_t func)
183{
184 unsigned long ip = (unsigned long)(&ftrace_call);
185 unsigned int upper = (unsigned int)func;
186 unsigned int lower = (unsigned int)func;
187 int ret = 0;
188
189
190 upper = 0xb0000000 + (upper >> 16);
191 lower = 0x32800000 + (lower & 0xFFFF);
192
193 pr_debug("%s: func=0x%x, ip=0x%x, upper=0x%x, lower=0x%x\n",
194 __func__, (unsigned int)func, (unsigned int)ip, upper, lower);
195
196
197 ret = ftrace_modify_code(ip, upper);
198 ret += ftrace_modify_code(ip + 4, lower);
199
200
201 ret += ftrace_modify_code((unsigned long)&ftrace_caller,
202 MICROBLAZE_NOP);
203
204 return ret;
205}
206
207#ifdef CONFIG_FUNCTION_GRAPH_TRACER
208unsigned int old_jump;
209
210int ftrace_enable_ftrace_graph_caller(void)
211{
212 unsigned int ret;
213 unsigned long ip = (unsigned long)(&ftrace_call_graph);
214
215 old_jump = *(unsigned int *)ip;
216 ret = ftrace_modify_code(ip, MICROBLAZE_NOP);
217
218 pr_debug("%s: Replace instruction: 0x%x\n", __func__, old_jump);
219 return ret;
220}
221
222int ftrace_disable_ftrace_graph_caller(void)
223{
224 unsigned int ret;
225 unsigned long ip = (unsigned long)(&ftrace_call_graph);
226
227 ret = ftrace_modify_code(ip, old_jump);
228
229 pr_debug("%s\n", __func__);
230 return ret;
231}
232#endif
233#endif
234