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Merge branches 'tracing/hw-branch-tracing' and 'tracing/branch-tracer' into tracing...
[mirror_ubuntu-zesty-kernel.git] / kernel / trace / trace_mmiotrace.c
1 /*
2 * Memory mapped I/O tracing
3 *
4 * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi>
5 */
6
7 #define DEBUG 1
8
9 #include <linux/kernel.h>
10 #include <linux/mmiotrace.h>
11 #include <linux/pci.h>
12
13 #include "trace.h"
14
15 struct header_iter {
16 struct pci_dev *dev;
17 };
18
19 static struct trace_array *mmio_trace_array;
20 static bool overrun_detected;
21 static unsigned long prev_overruns;
22
23 static void mmio_reset_data(struct trace_array *tr)
24 {
25 int cpu;
26
27 overrun_detected = false;
28 prev_overruns = 0;
29 tr->time_start = ftrace_now(tr->cpu);
30
31 for_each_online_cpu(cpu)
32 tracing_reset(tr, cpu);
33 }
34
35 static int mmio_trace_init(struct trace_array *tr)
36 {
37 pr_debug("in %s\n", __func__);
38 mmio_trace_array = tr;
39
40 mmio_reset_data(tr);
41 enable_mmiotrace();
42 return 0;
43 }
44
45 static void mmio_trace_reset(struct trace_array *tr)
46 {
47 pr_debug("in %s\n", __func__);
48
49 disable_mmiotrace();
50 mmio_reset_data(tr);
51 mmio_trace_array = NULL;
52 }
53
54 static void mmio_trace_start(struct trace_array *tr)
55 {
56 pr_debug("in %s\n", __func__);
57 mmio_reset_data(tr);
58 }
59
60 static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
61 {
62 int ret = 0;
63 int i;
64 resource_size_t start, end;
65 const struct pci_driver *drv = pci_dev_driver(dev);
66
67 /* XXX: incomplete checks for trace_seq_printf() return value */
68 ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
69 dev->bus->number, dev->devfn,
70 dev->vendor, dev->device, dev->irq);
71 /*
72 * XXX: is pci_resource_to_user() appropriate, since we are
73 * supposed to interpret the __ioremap() phys_addr argument based on
74 * these printed values?
75 */
76 for (i = 0; i < 7; i++) {
77 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
78 ret += trace_seq_printf(s, " %llx",
79 (unsigned long long)(start |
80 (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
81 }
82 for (i = 0; i < 7; i++) {
83 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
84 ret += trace_seq_printf(s, " %llx",
85 dev->resource[i].start < dev->resource[i].end ?
86 (unsigned long long)(end - start) + 1 : 0);
87 }
88 if (drv)
89 ret += trace_seq_printf(s, " %s\n", drv->name);
90 else
91 ret += trace_seq_printf(s, " \n");
92 return ret;
93 }
94
95 static void destroy_header_iter(struct header_iter *hiter)
96 {
97 if (!hiter)
98 return;
99 pci_dev_put(hiter->dev);
100 kfree(hiter);
101 }
102
103 static void mmio_pipe_open(struct trace_iterator *iter)
104 {
105 struct header_iter *hiter;
106 struct trace_seq *s = &iter->seq;
107
108 trace_seq_printf(s, "VERSION 20070824\n");
109
110 hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);
111 if (!hiter)
112 return;
113
114 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
115 iter->private = hiter;
116 }
117
118 /* XXX: This is not called when the pipe is closed! */
119 static void mmio_close(struct trace_iterator *iter)
120 {
121 struct header_iter *hiter = iter->private;
122 destroy_header_iter(hiter);
123 iter->private = NULL;
124 }
125
126 static unsigned long count_overruns(struct trace_iterator *iter)
127 {
128 unsigned long cnt = 0;
129 unsigned long over = ring_buffer_overruns(iter->tr->buffer);
130
131 if (over > prev_overruns)
132 cnt = over - prev_overruns;
133 prev_overruns = over;
134 return cnt;
135 }
136
137 static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
138 char __user *ubuf, size_t cnt, loff_t *ppos)
139 {
140 ssize_t ret;
141 struct header_iter *hiter = iter->private;
142 struct trace_seq *s = &iter->seq;
143 unsigned long n;
144
145 n = count_overruns(iter);
146 if (n) {
147 /* XXX: This is later than where events were lost. */
148 trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
149 if (!overrun_detected)
150 pr_warning("mmiotrace has lost events.\n");
151 overrun_detected = true;
152 goto print_out;
153 }
154
155 if (!hiter)
156 return 0;
157
158 mmio_print_pcidev(s, hiter->dev);
159 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
160
161 if (!hiter->dev) {
162 destroy_header_iter(hiter);
163 iter->private = NULL;
164 }
165
166 print_out:
167 ret = trace_seq_to_user(s, ubuf, cnt);
168 return (ret == -EBUSY) ? 0 : ret;
169 }
170
171 static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
172 {
173 struct trace_entry *entry = iter->ent;
174 struct trace_mmiotrace_rw *field;
175 struct mmiotrace_rw *rw;
176 struct trace_seq *s = &iter->seq;
177 unsigned long long t = ns2usecs(iter->ts);
178 unsigned long usec_rem = do_div(t, 1000000ULL);
179 unsigned secs = (unsigned long)t;
180 int ret = 1;
181
182 trace_assign_type(field, entry);
183 rw = &field->rw;
184
185 switch (rw->opcode) {
186 case MMIO_READ:
187 ret = trace_seq_printf(s,
188 "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
189 rw->width, secs, usec_rem, rw->map_id,
190 (unsigned long long)rw->phys,
191 rw->value, rw->pc, 0);
192 break;
193 case MMIO_WRITE:
194 ret = trace_seq_printf(s,
195 "W %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
196 rw->width, secs, usec_rem, rw->map_id,
197 (unsigned long long)rw->phys,
198 rw->value, rw->pc, 0);
199 break;
200 case MMIO_UNKNOWN_OP:
201 ret = trace_seq_printf(s,
202 "UNKNOWN %lu.%06lu %d 0x%llx %02x,%02x,%02x 0x%lx %d\n",
203 secs, usec_rem, rw->map_id,
204 (unsigned long long)rw->phys,
205 (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
206 (rw->value >> 0) & 0xff, rw->pc, 0);
207 break;
208 default:
209 ret = trace_seq_printf(s, "rw what?\n");
210 break;
211 }
212 if (ret)
213 return TRACE_TYPE_HANDLED;
214 return TRACE_TYPE_PARTIAL_LINE;
215 }
216
217 static enum print_line_t mmio_print_map(struct trace_iterator *iter)
218 {
219 struct trace_entry *entry = iter->ent;
220 struct trace_mmiotrace_map *field;
221 struct mmiotrace_map *m;
222 struct trace_seq *s = &iter->seq;
223 unsigned long long t = ns2usecs(iter->ts);
224 unsigned long usec_rem = do_div(t, 1000000ULL);
225 unsigned secs = (unsigned long)t;
226 int ret;
227
228 trace_assign_type(field, entry);
229 m = &field->map;
230
231 switch (m->opcode) {
232 case MMIO_PROBE:
233 ret = trace_seq_printf(s,
234 "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
235 secs, usec_rem, m->map_id,
236 (unsigned long long)m->phys, m->virt, m->len,
237 0UL, 0);
238 break;
239 case MMIO_UNPROBE:
240 ret = trace_seq_printf(s,
241 "UNMAP %lu.%06lu %d 0x%lx %d\n",
242 secs, usec_rem, m->map_id, 0UL, 0);
243 break;
244 default:
245 ret = trace_seq_printf(s, "map what?\n");
246 break;
247 }
248 if (ret)
249 return TRACE_TYPE_HANDLED;
250 return TRACE_TYPE_PARTIAL_LINE;
251 }
252
253 static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
254 {
255 struct trace_entry *entry = iter->ent;
256 struct print_entry *print = (struct print_entry *)entry;
257 const char *msg = print->buf;
258 struct trace_seq *s = &iter->seq;
259 unsigned long long t = ns2usecs(iter->ts);
260 unsigned long usec_rem = do_div(t, 1000000ULL);
261 unsigned secs = (unsigned long)t;
262 int ret;
263
264 /* The trailing newline must be in the message. */
265 ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg);
266 if (!ret)
267 return TRACE_TYPE_PARTIAL_LINE;
268
269 if (entry->flags & TRACE_FLAG_CONT)
270 trace_seq_print_cont(s, iter);
271
272 return TRACE_TYPE_HANDLED;
273 }
274
275 static enum print_line_t mmio_print_line(struct trace_iterator *iter)
276 {
277 switch (iter->ent->type) {
278 case TRACE_MMIO_RW:
279 return mmio_print_rw(iter);
280 case TRACE_MMIO_MAP:
281 return mmio_print_map(iter);
282 case TRACE_PRINT:
283 return mmio_print_mark(iter);
284 default:
285 return TRACE_TYPE_HANDLED; /* ignore unknown entries */
286 }
287 }
288
289 static struct tracer mmio_tracer __read_mostly =
290 {
291 .name = "mmiotrace",
292 .init = mmio_trace_init,
293 .reset = mmio_trace_reset,
294 .start = mmio_trace_start,
295 .pipe_open = mmio_pipe_open,
296 .close = mmio_close,
297 .read = mmio_read,
298 .print_line = mmio_print_line,
299 };
300
301 __init static int init_mmio_trace(void)
302 {
303 return register_tracer(&mmio_tracer);
304 }
305 device_initcall(init_mmio_trace);
306
307 static void __trace_mmiotrace_rw(struct trace_array *tr,
308 struct trace_array_cpu *data,
309 struct mmiotrace_rw *rw)
310 {
311 struct ring_buffer_event *event;
312 struct trace_mmiotrace_rw *entry;
313 unsigned long irq_flags;
314
315 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
316 &irq_flags);
317 if (!event)
318 return;
319 entry = ring_buffer_event_data(event);
320 tracing_generic_entry_update(&entry->ent, 0, preempt_count());
321 entry->ent.type = TRACE_MMIO_RW;
322 entry->rw = *rw;
323 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
324
325 trace_wake_up();
326 }
327
328 void mmio_trace_rw(struct mmiotrace_rw *rw)
329 {
330 struct trace_array *tr = mmio_trace_array;
331 struct trace_array_cpu *data = tr->data[smp_processor_id()];
332 __trace_mmiotrace_rw(tr, data, rw);
333 }
334
335 static void __trace_mmiotrace_map(struct trace_array *tr,
336 struct trace_array_cpu *data,
337 struct mmiotrace_map *map)
338 {
339 struct ring_buffer_event *event;
340 struct trace_mmiotrace_map *entry;
341 unsigned long irq_flags;
342
343 event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
344 &irq_flags);
345 if (!event)
346 return;
347 entry = ring_buffer_event_data(event);
348 tracing_generic_entry_update(&entry->ent, 0, preempt_count());
349 entry->ent.type = TRACE_MMIO_MAP;
350 entry->map = *map;
351 ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
352
353 trace_wake_up();
354 }
355
356 void mmio_trace_mapping(struct mmiotrace_map *map)
357 {
358 struct trace_array *tr = mmio_trace_array;
359 struct trace_array_cpu *data;
360
361 preempt_disable();
362 data = tr->data[smp_processor_id()];
363 __trace_mmiotrace_map(tr, data, map);
364 preempt_enable();
365 }
366
367 int mmio_trace_printk(const char *fmt, va_list args)
368 {
369 return trace_vprintk(0, fmt, args);
370 }