Merge tag '4.3-rc-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6
[sfrench/cifs-2.6.git] / kernel / trace / trace_mmiotrace.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Memory mapped I/O tracing
4  *
5  * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi>
6  */
7
8 #define DEBUG 1
9
10 #include <linux/kernel.h>
11 #include <linux/mmiotrace.h>
12 #include <linux/pci.h>
13 #include <linux/slab.h>
14 #include <linux/time.h>
15
16 #include <linux/atomic.h>
17
18 #include "trace.h"
19 #include "trace_output.h"
20
21 struct header_iter {
22         struct pci_dev *dev;
23 };
24
25 static struct trace_array *mmio_trace_array;
26 static bool overrun_detected;
27 static unsigned long prev_overruns;
28 static atomic_t dropped_count;
29
30 static void mmio_reset_data(struct trace_array *tr)
31 {
32         overrun_detected = false;
33         prev_overruns = 0;
34
35         tracing_reset_online_cpus(&tr->trace_buffer);
36 }
37
38 static int mmio_trace_init(struct trace_array *tr)
39 {
40         pr_debug("in %s\n", __func__);
41         mmio_trace_array = tr;
42
43         mmio_reset_data(tr);
44         enable_mmiotrace();
45         return 0;
46 }
47
48 static void mmio_trace_reset(struct trace_array *tr)
49 {
50         pr_debug("in %s\n", __func__);
51
52         disable_mmiotrace();
53         mmio_reset_data(tr);
54         mmio_trace_array = NULL;
55 }
56
57 static void mmio_trace_start(struct trace_array *tr)
58 {
59         pr_debug("in %s\n", __func__);
60         mmio_reset_data(tr);
61 }
62
63 static void mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
64 {
65         int i;
66         resource_size_t start, end;
67         const struct pci_driver *drv = pci_dev_driver(dev);
68
69         trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
70                          dev->bus->number, dev->devfn,
71                          dev->vendor, dev->device, dev->irq);
72         for (i = 0; i < 7; i++) {
73                 start = dev->resource[i].start;
74                 trace_seq_printf(s, " %llx",
75                         (unsigned long long)(start |
76                         (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
77         }
78         for (i = 0; i < 7; i++) {
79                 start = dev->resource[i].start;
80                 end = dev->resource[i].end;
81                 trace_seq_printf(s, " %llx",
82                         dev->resource[i].start < dev->resource[i].end ?
83                         (unsigned long long)(end - start) + 1 : 0);
84         }
85         if (drv)
86                 trace_seq_printf(s, " %s\n", drv->name);
87         else
88                 trace_seq_puts(s, " \n");
89 }
90
91 static void destroy_header_iter(struct header_iter *hiter)
92 {
93         if (!hiter)
94                 return;
95         pci_dev_put(hiter->dev);
96         kfree(hiter);
97 }
98
99 static void mmio_pipe_open(struct trace_iterator *iter)
100 {
101         struct header_iter *hiter;
102         struct trace_seq *s = &iter->seq;
103
104         trace_seq_puts(s, "VERSION 20070824\n");
105
106         hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);
107         if (!hiter)
108                 return;
109
110         hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
111         iter->private = hiter;
112 }
113
114 /* XXX: This is not called when the pipe is closed! */
115 static void mmio_close(struct trace_iterator *iter)
116 {
117         struct header_iter *hiter = iter->private;
118         destroy_header_iter(hiter);
119         iter->private = NULL;
120 }
121
122 static unsigned long count_overruns(struct trace_iterator *iter)
123 {
124         unsigned long cnt = atomic_xchg(&dropped_count, 0);
125         unsigned long over = ring_buffer_overruns(iter->trace_buffer->buffer);
126
127         if (over > prev_overruns)
128                 cnt += over - prev_overruns;
129         prev_overruns = over;
130         return cnt;
131 }
132
133 static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
134                                 char __user *ubuf, size_t cnt, loff_t *ppos)
135 {
136         ssize_t ret;
137         struct header_iter *hiter = iter->private;
138         struct trace_seq *s = &iter->seq;
139         unsigned long n;
140
141         n = count_overruns(iter);
142         if (n) {
143                 /* XXX: This is later than where events were lost. */
144                 trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
145                 if (!overrun_detected)
146                         pr_warn("mmiotrace has lost events\n");
147                 overrun_detected = true;
148                 goto print_out;
149         }
150
151         if (!hiter)
152                 return 0;
153
154         mmio_print_pcidev(s, hiter->dev);
155         hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
156
157         if (!hiter->dev) {
158                 destroy_header_iter(hiter);
159                 iter->private = NULL;
160         }
161
162 print_out:
163         ret = trace_seq_to_user(s, ubuf, cnt);
164         return (ret == -EBUSY) ? 0 : ret;
165 }
166
167 static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
168 {
169         struct trace_entry *entry = iter->ent;
170         struct trace_mmiotrace_rw *field;
171         struct mmiotrace_rw *rw;
172         struct trace_seq *s     = &iter->seq;
173         unsigned long long t    = ns2usecs(iter->ts);
174         unsigned long usec_rem  = do_div(t, USEC_PER_SEC);
175         unsigned secs           = (unsigned long)t;
176
177         trace_assign_type(field, entry);
178         rw = &field->rw;
179
180         switch (rw->opcode) {
181         case MMIO_READ:
182                 trace_seq_printf(s,
183                         "R %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
184                         rw->width, secs, usec_rem, rw->map_id,
185                         (unsigned long long)rw->phys,
186                         rw->value, rw->pc, 0);
187                 break;
188         case MMIO_WRITE:
189                 trace_seq_printf(s,
190                         "W %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_UNKNOWN_OP:
196                 trace_seq_printf(s,
197                         "UNKNOWN %u.%06lu %d 0x%llx %02lx,%02lx,"
198                         "%02lx 0x%lx %d\n",
199                         secs, usec_rem, rw->map_id,
200                         (unsigned long long)rw->phys,
201                         (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
202                         (rw->value >> 0) & 0xff, rw->pc, 0);
203                 break;
204         default:
205                 trace_seq_puts(s, "rw what?\n");
206                 break;
207         }
208
209         return trace_handle_return(s);
210 }
211
212 static enum print_line_t mmio_print_map(struct trace_iterator *iter)
213 {
214         struct trace_entry *entry = iter->ent;
215         struct trace_mmiotrace_map *field;
216         struct mmiotrace_map *m;
217         struct trace_seq *s     = &iter->seq;
218         unsigned long long t    = ns2usecs(iter->ts);
219         unsigned long usec_rem  = do_div(t, USEC_PER_SEC);
220         unsigned secs           = (unsigned long)t;
221
222         trace_assign_type(field, entry);
223         m = &field->map;
224
225         switch (m->opcode) {
226         case MMIO_PROBE:
227                 trace_seq_printf(s,
228                         "MAP %u.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
229                         secs, usec_rem, m->map_id,
230                         (unsigned long long)m->phys, m->virt, m->len,
231                         0UL, 0);
232                 break;
233         case MMIO_UNPROBE:
234                 trace_seq_printf(s,
235                         "UNMAP %u.%06lu %d 0x%lx %d\n",
236                         secs, usec_rem, m->map_id, 0UL, 0);
237                 break;
238         default:
239                 trace_seq_puts(s, "map what?\n");
240                 break;
241         }
242
243         return trace_handle_return(s);
244 }
245
246 static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
247 {
248         struct trace_entry *entry = iter->ent;
249         struct print_entry *print = (struct print_entry *)entry;
250         const char *msg         = print->buf;
251         struct trace_seq *s     = &iter->seq;
252         unsigned long long t    = ns2usecs(iter->ts);
253         unsigned long usec_rem  = do_div(t, USEC_PER_SEC);
254         unsigned secs           = (unsigned long)t;
255
256         /* The trailing newline must be in the message. */
257         trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg);
258
259         return trace_handle_return(s);
260 }
261
262 static enum print_line_t mmio_print_line(struct trace_iterator *iter)
263 {
264         switch (iter->ent->type) {
265         case TRACE_MMIO_RW:
266                 return mmio_print_rw(iter);
267         case TRACE_MMIO_MAP:
268                 return mmio_print_map(iter);
269         case TRACE_PRINT:
270                 return mmio_print_mark(iter);
271         default:
272                 return TRACE_TYPE_HANDLED; /* ignore unknown entries */
273         }
274 }
275
276 static struct tracer mmio_tracer __read_mostly =
277 {
278         .name           = "mmiotrace",
279         .init           = mmio_trace_init,
280         .reset          = mmio_trace_reset,
281         .start          = mmio_trace_start,
282         .pipe_open      = mmio_pipe_open,
283         .close          = mmio_close,
284         .read           = mmio_read,
285         .print_line     = mmio_print_line,
286         .noboot         = true,
287 };
288
289 __init static int init_mmio_trace(void)
290 {
291         return register_tracer(&mmio_tracer);
292 }
293 device_initcall(init_mmio_trace);
294
295 static void __trace_mmiotrace_rw(struct trace_array *tr,
296                                 struct trace_array_cpu *data,
297                                 struct mmiotrace_rw *rw)
298 {
299         struct trace_event_call *call = &event_mmiotrace_rw;
300         struct ring_buffer *buffer = tr->trace_buffer.buffer;
301         struct ring_buffer_event *event;
302         struct trace_mmiotrace_rw *entry;
303         int pc = preempt_count();
304
305         event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW,
306                                           sizeof(*entry), 0, pc);
307         if (!event) {
308                 atomic_inc(&dropped_count);
309                 return;
310         }
311         entry   = ring_buffer_event_data(event);
312         entry->rw                       = *rw;
313
314         if (!call_filter_check_discard(call, entry, buffer, event))
315                 trace_buffer_unlock_commit(tr, buffer, event, 0, pc);
316 }
317
318 void mmio_trace_rw(struct mmiotrace_rw *rw)
319 {
320         struct trace_array *tr = mmio_trace_array;
321         struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
322         __trace_mmiotrace_rw(tr, data, rw);
323 }
324
325 static void __trace_mmiotrace_map(struct trace_array *tr,
326                                 struct trace_array_cpu *data,
327                                 struct mmiotrace_map *map)
328 {
329         struct trace_event_call *call = &event_mmiotrace_map;
330         struct ring_buffer *buffer = tr->trace_buffer.buffer;
331         struct ring_buffer_event *event;
332         struct trace_mmiotrace_map *entry;
333         int pc = preempt_count();
334
335         event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP,
336                                           sizeof(*entry), 0, pc);
337         if (!event) {
338                 atomic_inc(&dropped_count);
339                 return;
340         }
341         entry   = ring_buffer_event_data(event);
342         entry->map                      = *map;
343
344         if (!call_filter_check_discard(call, entry, buffer, event))
345                 trace_buffer_unlock_commit(tr, buffer, event, 0, pc);
346 }
347
348 void mmio_trace_mapping(struct mmiotrace_map *map)
349 {
350         struct trace_array *tr = mmio_trace_array;
351         struct trace_array_cpu *data;
352
353         preempt_disable();
354         data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id());
355         __trace_mmiotrace_map(tr, data, map);
356         preempt_enable();
357 }
358
359 int mmio_trace_printk(const char *fmt, va_list args)
360 {
361         return trace_vprintk(0, fmt, args);
362 }