Merge branch 'sched/urgent' into sched/core
[linux-2.6] / 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 void mmio_trace_init(struct trace_array *tr)
36 {
37         pr_debug("in %s\n", __func__);
38         mmio_trace_array = tr;
39         if (tr->ctrl) {
40                 mmio_reset_data(tr);
41                 enable_mmiotrace();
42         }
43 }
44
45 static void mmio_trace_reset(struct trace_array *tr)
46 {
47         pr_debug("in %s\n", __func__);
48         if (tr->ctrl)
49                 disable_mmiotrace();
50         mmio_reset_data(tr);
51         mmio_trace_array = NULL;
52 }
53
54 static void mmio_trace_ctrl_update(struct trace_array *tr)
55 {
56         pr_debug("in %s\n", __func__);
57         if (tr->ctrl) {
58                 mmio_reset_data(tr);
59                 enable_mmiotrace();
60         } else {
61                 disable_mmiotrace();
62         }
63 }
64
65 static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
66 {
67         int ret = 0;
68         int i;
69         resource_size_t start, end;
70         const struct pci_driver *drv = pci_dev_driver(dev);
71
72         /* XXX: incomplete checks for trace_seq_printf() return value */
73         ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
74                                 dev->bus->number, dev->devfn,
75                                 dev->vendor, dev->device, dev->irq);
76         /*
77          * XXX: is pci_resource_to_user() appropriate, since we are
78          * supposed to interpret the __ioremap() phys_addr argument based on
79          * these printed values?
80          */
81         for (i = 0; i < 7; i++) {
82                 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
83                 ret += trace_seq_printf(s, " %llx",
84                         (unsigned long long)(start |
85                         (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
86         }
87         for (i = 0; i < 7; i++) {
88                 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
89                 ret += trace_seq_printf(s, " %llx",
90                         dev->resource[i].start < dev->resource[i].end ?
91                         (unsigned long long)(end - start) + 1 : 0);
92         }
93         if (drv)
94                 ret += trace_seq_printf(s, " %s\n", drv->name);
95         else
96                 ret += trace_seq_printf(s, " \n");
97         return ret;
98 }
99
100 static void destroy_header_iter(struct header_iter *hiter)
101 {
102         if (!hiter)
103                 return;
104         pci_dev_put(hiter->dev);
105         kfree(hiter);
106 }
107
108 static void mmio_pipe_open(struct trace_iterator *iter)
109 {
110         struct header_iter *hiter;
111         struct trace_seq *s = &iter->seq;
112
113         trace_seq_printf(s, "VERSION 20070824\n");
114
115         hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);
116         if (!hiter)
117                 return;
118
119         hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
120         iter->private = hiter;
121 }
122
123 /* XXX: This is not called when the pipe is closed! */
124 static void mmio_close(struct trace_iterator *iter)
125 {
126         struct header_iter *hiter = iter->private;
127         destroy_header_iter(hiter);
128         iter->private = NULL;
129 }
130
131 static unsigned long count_overruns(struct trace_iterator *iter)
132 {
133         unsigned long cnt = 0;
134         unsigned long over = ring_buffer_overruns(iter->tr->buffer);
135
136         if (over > prev_overruns)
137                 cnt = over - prev_overruns;
138         prev_overruns = over;
139         return cnt;
140 }
141
142 static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
143                                 char __user *ubuf, size_t cnt, loff_t *ppos)
144 {
145         ssize_t ret;
146         struct header_iter *hiter = iter->private;
147         struct trace_seq *s = &iter->seq;
148         unsigned long n;
149
150         n = count_overruns(iter);
151         if (n) {
152                 /* XXX: This is later than where events were lost. */
153                 trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
154                 if (!overrun_detected)
155                         pr_warning("mmiotrace has lost events.\n");
156                 overrun_detected = true;
157                 goto print_out;
158         }
159
160         if (!hiter)
161                 return 0;
162
163         mmio_print_pcidev(s, hiter->dev);
164         hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
165
166         if (!hiter->dev) {
167                 destroy_header_iter(hiter);
168                 iter->private = NULL;
169         }
170
171 print_out:
172         ret = trace_seq_to_user(s, ubuf, cnt);
173         return (ret == -EBUSY) ? 0 : ret;
174 }
175
176 static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
177 {
178         struct trace_entry *entry = iter->ent;
179         struct trace_mmiotrace_rw *field;
180         struct mmiotrace_rw *rw;
181         struct trace_seq *s     = &iter->seq;
182         unsigned long long t    = ns2usecs(iter->ts);
183         unsigned long usec_rem  = do_div(t, 1000000ULL);
184         unsigned secs           = (unsigned long)t;
185         int ret = 1;
186
187         trace_assign_type(field, entry);
188         rw = &field->rw;
189
190         switch (rw->opcode) {
191         case MMIO_READ:
192                 ret = trace_seq_printf(s,
193                         "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
194                         rw->width, secs, usec_rem, rw->map_id,
195                         (unsigned long long)rw->phys,
196                         rw->value, rw->pc, 0);
197                 break;
198         case MMIO_WRITE:
199                 ret = trace_seq_printf(s,
200                         "W %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
201                         rw->width, secs, usec_rem, rw->map_id,
202                         (unsigned long long)rw->phys,
203                         rw->value, rw->pc, 0);
204                 break;
205         case MMIO_UNKNOWN_OP:
206                 ret = trace_seq_printf(s,
207                         "UNKNOWN %lu.%06lu %d 0x%llx %02x,%02x,%02x 0x%lx %d\n",
208                         secs, usec_rem, rw->map_id,
209                         (unsigned long long)rw->phys,
210                         (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
211                         (rw->value >> 0) & 0xff, rw->pc, 0);
212                 break;
213         default:
214                 ret = trace_seq_printf(s, "rw what?\n");
215                 break;
216         }
217         if (ret)
218                 return TRACE_TYPE_HANDLED;
219         return TRACE_TYPE_PARTIAL_LINE;
220 }
221
222 static enum print_line_t mmio_print_map(struct trace_iterator *iter)
223 {
224         struct trace_entry *entry = iter->ent;
225         struct trace_mmiotrace_map *field;
226         struct mmiotrace_map *m;
227         struct trace_seq *s     = &iter->seq;
228         unsigned long long t    = ns2usecs(iter->ts);
229         unsigned long usec_rem  = do_div(t, 1000000ULL);
230         unsigned secs           = (unsigned long)t;
231         int ret;
232
233         trace_assign_type(field, entry);
234         m = &field->map;
235
236         switch (m->opcode) {
237         case MMIO_PROBE:
238                 ret = trace_seq_printf(s,
239                         "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
240                         secs, usec_rem, m->map_id,
241                         (unsigned long long)m->phys, m->virt, m->len,
242                         0UL, 0);
243                 break;
244         case MMIO_UNPROBE:
245                 ret = trace_seq_printf(s,
246                         "UNMAP %lu.%06lu %d 0x%lx %d\n",
247                         secs, usec_rem, m->map_id, 0UL, 0);
248                 break;
249         default:
250                 ret = trace_seq_printf(s, "map what?\n");
251                 break;
252         }
253         if (ret)
254                 return TRACE_TYPE_HANDLED;
255         return TRACE_TYPE_PARTIAL_LINE;
256 }
257
258 static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
259 {
260         struct trace_entry *entry = iter->ent;
261         struct print_entry *print = (struct print_entry *)entry;
262         const char *msg         = print->buf;
263         struct trace_seq *s     = &iter->seq;
264         unsigned long long t    = ns2usecs(iter->ts);
265         unsigned long usec_rem  = do_div(t, 1000000ULL);
266         unsigned secs           = (unsigned long)t;
267         int ret;
268
269         /* The trailing newline must be in the message. */
270         ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg);
271         if (!ret)
272                 return TRACE_TYPE_PARTIAL_LINE;
273
274         if (entry->flags & TRACE_FLAG_CONT)
275                 trace_seq_print_cont(s, iter);
276
277         return TRACE_TYPE_HANDLED;
278 }
279
280 static enum print_line_t mmio_print_line(struct trace_iterator *iter)
281 {
282         switch (iter->ent->type) {
283         case TRACE_MMIO_RW:
284                 return mmio_print_rw(iter);
285         case TRACE_MMIO_MAP:
286                 return mmio_print_map(iter);
287         case TRACE_PRINT:
288                 return mmio_print_mark(iter);
289         default:
290                 return TRACE_TYPE_HANDLED; /* ignore unknown entries */
291         }
292 }
293
294 static struct tracer mmio_tracer __read_mostly =
295 {
296         .name           = "mmiotrace",
297         .init           = mmio_trace_init,
298         .reset          = mmio_trace_reset,
299         .pipe_open      = mmio_pipe_open,
300         .close          = mmio_close,
301         .read           = mmio_read,
302         .ctrl_update    = mmio_trace_ctrl_update,
303         .print_line     = mmio_print_line,
304 };
305
306 __init static int init_mmio_trace(void)
307 {
308         return register_tracer(&mmio_tracer);
309 }
310 device_initcall(init_mmio_trace);
311
312 static void __trace_mmiotrace_rw(struct trace_array *tr,
313                                 struct trace_array_cpu *data,
314                                 struct mmiotrace_rw *rw)
315 {
316         struct ring_buffer_event *event;
317         struct trace_mmiotrace_rw *entry;
318         unsigned long irq_flags;
319
320         event   = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
321                                            &irq_flags);
322         if (!event)
323                 return;
324         entry   = ring_buffer_event_data(event);
325         tracing_generic_entry_update(&entry->ent, 0, preempt_count());
326         entry->ent.type                 = TRACE_MMIO_RW;
327         entry->rw                       = *rw;
328         ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
329
330         trace_wake_up();
331 }
332
333 void mmio_trace_rw(struct mmiotrace_rw *rw)
334 {
335         struct trace_array *tr = mmio_trace_array;
336         struct trace_array_cpu *data = tr->data[smp_processor_id()];
337         __trace_mmiotrace_rw(tr, data, rw);
338 }
339
340 static void __trace_mmiotrace_map(struct trace_array *tr,
341                                 struct trace_array_cpu *data,
342                                 struct mmiotrace_map *map)
343 {
344         struct ring_buffer_event *event;
345         struct trace_mmiotrace_map *entry;
346         unsigned long irq_flags;
347
348         event   = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
349                                            &irq_flags);
350         if (!event)
351                 return;
352         entry   = ring_buffer_event_data(event);
353         tracing_generic_entry_update(&entry->ent, 0, preempt_count());
354         entry->ent.type                 = TRACE_MMIO_MAP;
355         entry->map                      = *map;
356         ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
357
358         trace_wake_up();
359 }
360
361 void mmio_trace_mapping(struct mmiotrace_map *map)
362 {
363         struct trace_array *tr = mmio_trace_array;
364         struct trace_array_cpu *data;
365
366         preempt_disable();
367         data = tr->data[smp_processor_id()];
368         __trace_mmiotrace_map(tr, data, map);
369         preempt_enable();
370 }
371
372 int mmio_trace_printk(const char *fmt, va_list args)
373 {
374         return trace_vprintk(0, fmt, args);
375 }