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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 | #include <linux/slab.h> | |
13 | #include <linux/time.h> | |
14 | ||
15 | #include <linux/atomic.h> | |
16 | ||
17 | #include "trace.h" | |
18 | #include "trace_output.h" | |
19 | ||
20 | struct header_iter { | |
21 | struct pci_dev *dev; | |
22 | }; | |
23 | ||
24 | static struct trace_array *mmio_trace_array; | |
25 | static bool overrun_detected; | |
26 | static unsigned long prev_overruns; | |
27 | static atomic_t dropped_count; | |
28 | ||
29 | static void mmio_reset_data(struct trace_array *tr) | |
30 | { | |
31 | overrun_detected = false; | |
32 | prev_overruns = 0; | |
33 | ||
34 | tracing_reset_online_cpus(&tr->trace_buffer); | |
35 | } | |
36 | ||
37 | static int mmio_trace_init(struct trace_array *tr) | |
38 | { | |
39 | pr_debug("in %s\n", __func__); | |
40 | mmio_trace_array = tr; | |
41 | ||
42 | mmio_reset_data(tr); | |
43 | enable_mmiotrace(); | |
44 | return 0; | |
45 | } | |
46 | ||
47 | static void mmio_trace_reset(struct trace_array *tr) | |
48 | { | |
49 | pr_debug("in %s\n", __func__); | |
50 | ||
51 | disable_mmiotrace(); | |
52 | mmio_reset_data(tr); | |
53 | mmio_trace_array = NULL; | |
54 | } | |
55 | ||
56 | static void mmio_trace_start(struct trace_array *tr) | |
57 | { | |
58 | pr_debug("in %s\n", __func__); | |
59 | mmio_reset_data(tr); | |
60 | } | |
61 | ||
62 | static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) | |
63 | { | |
64 | int ret = 0; | |
65 | int i; | |
66 | resource_size_t start, end; | |
67 | const struct pci_driver *drv = pci_dev_driver(dev); | |
68 | ||
69 | /* XXX: incomplete checks for trace_seq_printf() return value */ | |
70 | ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x", | |
71 | dev->bus->number, dev->devfn, | |
72 | dev->vendor, dev->device, dev->irq); | |
73 | /* | |
74 | * XXX: is pci_resource_to_user() appropriate, since we are | |
75 | * supposed to interpret the __ioremap() phys_addr argument based on | |
76 | * these printed values? | |
77 | */ | |
78 | for (i = 0; i < 7; i++) { | |
79 | pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); | |
80 | ret += trace_seq_printf(s, " %llx", | |
81 | (unsigned long long)(start | | |
82 | (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); | |
83 | } | |
84 | for (i = 0; i < 7; i++) { | |
85 | pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); | |
86 | ret += trace_seq_printf(s, " %llx", | |
87 | dev->resource[i].start < dev->resource[i].end ? | |
88 | (unsigned long long)(end - start) + 1 : 0); | |
89 | } | |
90 | if (drv) | |
91 | ret += trace_seq_printf(s, " %s\n", drv->name); | |
92 | else | |
93 | ret += trace_seq_puts(s, " \n"); | |
94 | return ret; | |
95 | } | |
96 | ||
97 | static void destroy_header_iter(struct header_iter *hiter) | |
98 | { | |
99 | if (!hiter) | |
100 | return; | |
101 | pci_dev_put(hiter->dev); | |
102 | kfree(hiter); | |
103 | } | |
104 | ||
105 | static void mmio_pipe_open(struct trace_iterator *iter) | |
106 | { | |
107 | struct header_iter *hiter; | |
108 | struct trace_seq *s = &iter->seq; | |
109 | ||
110 | trace_seq_puts(s, "VERSION 20070824\n"); | |
111 | ||
112 | hiter = kzalloc(sizeof(*hiter), GFP_KERNEL); | |
113 | if (!hiter) | |
114 | return; | |
115 | ||
116 | hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL); | |
117 | iter->private = hiter; | |
118 | } | |
119 | ||
120 | /* XXX: This is not called when the pipe is closed! */ | |
121 | static void mmio_close(struct trace_iterator *iter) | |
122 | { | |
123 | struct header_iter *hiter = iter->private; | |
124 | destroy_header_iter(hiter); | |
125 | iter->private = NULL; | |
126 | } | |
127 | ||
128 | static unsigned long count_overruns(struct trace_iterator *iter) | |
129 | { | |
130 | unsigned long cnt = atomic_xchg(&dropped_count, 0); | |
131 | unsigned long over = ring_buffer_overruns(iter->trace_buffer->buffer); | |
132 | ||
133 | if (over > prev_overruns) | |
134 | cnt += over - prev_overruns; | |
135 | prev_overruns = over; | |
136 | return cnt; | |
137 | } | |
138 | ||
139 | static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp, | |
140 | char __user *ubuf, size_t cnt, loff_t *ppos) | |
141 | { | |
142 | ssize_t ret; | |
143 | struct header_iter *hiter = iter->private; | |
144 | struct trace_seq *s = &iter->seq; | |
145 | unsigned long n; | |
146 | ||
147 | n = count_overruns(iter); | |
148 | if (n) { | |
149 | /* XXX: This is later than where events were lost. */ | |
150 | trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n); | |
151 | if (!overrun_detected) | |
152 | pr_warning("mmiotrace has lost events.\n"); | |
153 | overrun_detected = true; | |
154 | goto print_out; | |
155 | } | |
156 | ||
157 | if (!hiter) | |
158 | return 0; | |
159 | ||
160 | mmio_print_pcidev(s, hiter->dev); | |
161 | hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev); | |
162 | ||
163 | if (!hiter->dev) { | |
164 | destroy_header_iter(hiter); | |
165 | iter->private = NULL; | |
166 | } | |
167 | ||
168 | print_out: | |
169 | ret = trace_seq_to_user(s, ubuf, cnt); | |
170 | return (ret == -EBUSY) ? 0 : ret; | |
171 | } | |
172 | ||
173 | static enum print_line_t mmio_print_rw(struct trace_iterator *iter) | |
174 | { | |
175 | struct trace_entry *entry = iter->ent; | |
176 | struct trace_mmiotrace_rw *field; | |
177 | struct mmiotrace_rw *rw; | |
178 | struct trace_seq *s = &iter->seq; | |
179 | unsigned long long t = ns2usecs(iter->ts); | |
180 | unsigned long usec_rem = do_div(t, USEC_PER_SEC); | |
181 | unsigned secs = (unsigned long)t; | |
182 | int ret = 1; | |
183 | ||
184 | trace_assign_type(field, entry); | |
185 | rw = &field->rw; | |
186 | ||
187 | switch (rw->opcode) { | |
188 | case MMIO_READ: | |
189 | ret = trace_seq_printf(s, | |
190 | "R %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", | |
191 | rw->width, secs, usec_rem, rw->map_id, | |
192 | (unsigned long long)rw->phys, | |
193 | rw->value, rw->pc, 0); | |
194 | break; | |
195 | case MMIO_WRITE: | |
196 | ret = trace_seq_printf(s, | |
197 | "W %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", | |
198 | rw->width, secs, usec_rem, rw->map_id, | |
199 | (unsigned long long)rw->phys, | |
200 | rw->value, rw->pc, 0); | |
201 | break; | |
202 | case MMIO_UNKNOWN_OP: | |
203 | ret = trace_seq_printf(s, | |
204 | "UNKNOWN %u.%06lu %d 0x%llx %02lx,%02lx," | |
205 | "%02lx 0x%lx %d\n", | |
206 | secs, usec_rem, rw->map_id, | |
207 | (unsigned long long)rw->phys, | |
208 | (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff, | |
209 | (rw->value >> 0) & 0xff, rw->pc, 0); | |
210 | break; | |
211 | default: | |
212 | ret = trace_seq_puts(s, "rw what?\n"); | |
213 | break; | |
214 | } | |
215 | if (ret) | |
216 | return TRACE_TYPE_HANDLED; | |
217 | return TRACE_TYPE_PARTIAL_LINE; | |
218 | } | |
219 | ||
220 | static enum print_line_t mmio_print_map(struct trace_iterator *iter) | |
221 | { | |
222 | struct trace_entry *entry = iter->ent; | |
223 | struct trace_mmiotrace_map *field; | |
224 | struct mmiotrace_map *m; | |
225 | struct trace_seq *s = &iter->seq; | |
226 | unsigned long long t = ns2usecs(iter->ts); | |
227 | unsigned long usec_rem = do_div(t, USEC_PER_SEC); | |
228 | unsigned secs = (unsigned long)t; | |
229 | int ret; | |
230 | ||
231 | trace_assign_type(field, entry); | |
232 | m = &field->map; | |
233 | ||
234 | switch (m->opcode) { | |
235 | case MMIO_PROBE: | |
236 | ret = trace_seq_printf(s, | |
237 | "MAP %u.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", | |
238 | secs, usec_rem, m->map_id, | |
239 | (unsigned long long)m->phys, m->virt, m->len, | |
240 | 0UL, 0); | |
241 | break; | |
242 | case MMIO_UNPROBE: | |
243 | ret = trace_seq_printf(s, | |
244 | "UNMAP %u.%06lu %d 0x%lx %d\n", | |
245 | secs, usec_rem, m->map_id, 0UL, 0); | |
246 | break; | |
247 | default: | |
248 | ret = trace_seq_puts(s, "map what?\n"); | |
249 | break; | |
250 | } | |
251 | if (ret) | |
252 | return TRACE_TYPE_HANDLED; | |
253 | return TRACE_TYPE_PARTIAL_LINE; | |
254 | } | |
255 | ||
256 | static enum print_line_t mmio_print_mark(struct trace_iterator *iter) | |
257 | { | |
258 | struct trace_entry *entry = iter->ent; | |
259 | struct print_entry *print = (struct print_entry *)entry; | |
260 | const char *msg = print->buf; | |
261 | struct trace_seq *s = &iter->seq; | |
262 | unsigned long long t = ns2usecs(iter->ts); | |
263 | unsigned long usec_rem = do_div(t, USEC_PER_SEC); | |
264 | unsigned secs = (unsigned long)t; | |
265 | int ret; | |
266 | ||
267 | /* The trailing newline must be in the message. */ | |
268 | ret = trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg); | |
269 | if (!ret) | |
270 | return TRACE_TYPE_PARTIAL_LINE; | |
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 ftrace_event_call *call = &event_mmiotrace_rw; | |
312 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
313 | struct ring_buffer_event *event; | |
314 | struct trace_mmiotrace_rw *entry; | |
315 | int pc = preempt_count(); | |
316 | ||
317 | event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW, | |
318 | sizeof(*entry), 0, pc); | |
319 | if (!event) { | |
320 | atomic_inc(&dropped_count); | |
321 | return; | |
322 | } | |
323 | entry = ring_buffer_event_data(event); | |
324 | entry->rw = *rw; | |
325 | ||
326 | if (!filter_check_discard(call, entry, buffer, event)) | |
327 | trace_buffer_unlock_commit(buffer, event, 0, pc); | |
328 | } | |
329 | ||
330 | void mmio_trace_rw(struct mmiotrace_rw *rw) | |
331 | { | |
332 | struct trace_array *tr = mmio_trace_array; | |
333 | struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id()); | |
334 | __trace_mmiotrace_rw(tr, data, rw); | |
335 | } | |
336 | ||
337 | static void __trace_mmiotrace_map(struct trace_array *tr, | |
338 | struct trace_array_cpu *data, | |
339 | struct mmiotrace_map *map) | |
340 | { | |
341 | struct ftrace_event_call *call = &event_mmiotrace_map; | |
342 | struct ring_buffer *buffer = tr->trace_buffer.buffer; | |
343 | struct ring_buffer_event *event; | |
344 | struct trace_mmiotrace_map *entry; | |
345 | int pc = preempt_count(); | |
346 | ||
347 | event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP, | |
348 | sizeof(*entry), 0, pc); | |
349 | if (!event) { | |
350 | atomic_inc(&dropped_count); | |
351 | return; | |
352 | } | |
353 | entry = ring_buffer_event_data(event); | |
354 | entry->map = *map; | |
355 | ||
356 | if (!filter_check_discard(call, entry, buffer, event)) | |
357 | trace_buffer_unlock_commit(buffer, event, 0, pc); | |
358 | } | |
359 | ||
360 | void mmio_trace_mapping(struct mmiotrace_map *map) | |
361 | { | |
362 | struct trace_array *tr = mmio_trace_array; | |
363 | struct trace_array_cpu *data; | |
364 | ||
365 | preempt_disable(); | |
366 | data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id()); | |
367 | __trace_mmiotrace_map(tr, data, map); | |
368 | preempt_enable(); | |
369 | } | |
370 | ||
371 | int mmio_trace_printk(const char *fmt, va_list args) | |
372 | { | |
373 | return trace_vprintk(0, fmt, args); | |
374 | } |