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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Memory mapped I/O tracing
4 *
5 * Copyright (C) 2008 Pekka Paalanen <[email protected]>
6 */
7
8#include <linux/kernel.h>
9#include <linux/mmiotrace.h>
10#include <linux/pci.h>
11#include <linux/slab.h>
12#include <linux/time.h>
13
14#include <linux/atomic.h>
15
16#include "trace.h"
17#include "trace_output.h"
18
19struct header_iter {
20 struct pci_dev *dev;
21};
22
23static struct trace_array *mmio_trace_array;
24static bool overrun_detected;
25static unsigned long prev_overruns;
26static atomic_t dropped_count;
27
28static void mmio_reset_data(struct trace_array *tr)
29{
30 overrun_detected = false;
31 prev_overruns = 0;
32 atomic_set(&dropped_count, 0);
33
34 tracing_reset_online_cpus(&tr->array_buffer);
35}
36
37static 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
47static 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
56static void mmio_trace_start(struct trace_array *tr)
57{
58 pr_debug("in %s\n", __func__);
59 mmio_reset_data(tr);
60}
61
62static void mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
63{
64 int i;
65 resource_size_t start, end;
66 const struct pci_driver *drv = pci_dev_driver(dev);
67
68 trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
69 dev->bus->number, dev->devfn,
70 dev->vendor, dev->device, dev->irq);
71 for (i = 0; i < 7; i++) {
72 start = dev->resource[i].start;
73 trace_seq_printf(s, " %llx",
74 (unsigned long long)(start |
75 (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
76 }
77 for (i = 0; i < 7; i++) {
78 start = dev->resource[i].start;
79 end = dev->resource[i].end;
80 trace_seq_printf(s, " %llx",
81 dev->resource[i].start < dev->resource[i].end ?
82 (unsigned long long)(end - start) + 1 : 0);
83 }
84 if (drv)
85 trace_seq_printf(s, " %s\n", drv->name);
86 else
87 trace_seq_puts(s, " \n");
88}
89
90static void destroy_header_iter(struct header_iter *hiter)
91{
92 if (!hiter)
93 return;
94 pci_dev_put(hiter->dev);
95 kfree(hiter);
96}
97
98static void mmio_pipe_open(struct trace_iterator *iter)
99{
100 struct header_iter *hiter;
101 struct trace_seq *s = &iter->seq;
102
103 trace_seq_puts(s, "VERSION 20070824\n");
104
105 hiter = kzalloc_obj(*hiter);
106 if (!hiter)
107 return;
108
109 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
110 iter->private = hiter;
111}
112
113static void mmio_close(struct trace_iterator *iter)
114{
115 struct header_iter *hiter = iter->private;
116 destroy_header_iter(hiter);
117 iter->private = NULL;
118}
119
120static unsigned long count_overruns(struct trace_iterator *iter)
121{
122 unsigned long cnt = atomic_xchg(&dropped_count, 0);
123 unsigned long over = ring_buffer_overruns(iter->array_buffer->buffer);
124
125 if (over > prev_overruns)
126 cnt += over - prev_overruns;
127 prev_overruns = over;
128 return cnt;
129}
130
131static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
132 char __user *ubuf, size_t cnt, loff_t *ppos)
133{
134 ssize_t ret;
135 struct header_iter *hiter = iter->private;
136 struct trace_seq *s = &iter->seq;
137 unsigned long n;
138
139 n = count_overruns(iter);
140 if (n) {
141 /* XXX: This is later than where events were lost. */
142 trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
143 if (!overrun_detected)
144 pr_warn("mmiotrace has lost events\n");
145 overrun_detected = true;
146 goto print_out;
147 }
148
149 if (!hiter || !hiter->dev)
150 return 0;
151
152 mmio_print_pcidev(s, hiter->dev);
153 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
154
155 if (!hiter->dev) {
156 destroy_header_iter(hiter);
157 iter->private = NULL;
158 }
159
160print_out:
161 ret = trace_seq_to_user(s, ubuf, cnt);
162 return (ret == -EBUSY) ? 0 : ret;
163}
164
165static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
166{
167 struct trace_entry *entry = iter->ent;
168 struct trace_mmiotrace_rw *field;
169 struct mmiotrace_rw *rw;
170 struct trace_seq *s = &iter->seq;
171 unsigned long long t = ns2usecs(iter->ts);
172 unsigned long usec_rem = do_div(t, USEC_PER_SEC);
173 unsigned secs = (unsigned long)t;
174
175 trace_assign_type(field, entry);
176 rw = &field->rw;
177
178 switch (rw->opcode) {
179 case MMIO_READ:
180 trace_seq_printf(s,
181 "R %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
182 rw->width, secs, usec_rem, rw->map_id,
183 (unsigned long long)rw->phys,
184 rw->value, rw->pc, 0);
185 break;
186 case MMIO_WRITE:
187 trace_seq_printf(s,
188 "W %d %u.%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_UNKNOWN_OP:
194 trace_seq_printf(s,
195 "UNKNOWN %u.%06lu %d 0x%llx %02lx,%02lx,"
196 "%02lx 0x%lx %d\n",
197 secs, usec_rem, rw->map_id,
198 (unsigned long long)rw->phys,
199 (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
200 (rw->value >> 0) & 0xff, rw->pc, 0);
201 break;
202 default:
203 trace_seq_puts(s, "rw what?\n");
204 break;
205 }
206
207 return trace_handle_return(s);
208}
209
210static enum print_line_t mmio_print_map(struct trace_iterator *iter)
211{
212 struct trace_entry *entry = iter->ent;
213 struct trace_mmiotrace_map *field;
214 struct mmiotrace_map *m;
215 struct trace_seq *s = &iter->seq;
216 unsigned long long t = ns2usecs(iter->ts);
217 unsigned long usec_rem = do_div(t, USEC_PER_SEC);
218 unsigned secs = (unsigned long)t;
219
220 trace_assign_type(field, entry);
221 m = &field->map;
222
223 switch (m->opcode) {
224 case MMIO_PROBE:
225 trace_seq_printf(s,
226 "MAP %u.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
227 secs, usec_rem, m->map_id,
228 (unsigned long long)m->phys, m->virt, m->len,
229 0UL, 0);
230 break;
231 case MMIO_UNPROBE:
232 trace_seq_printf(s,
233 "UNMAP %u.%06lu %d 0x%lx %d\n",
234 secs, usec_rem, m->map_id, 0UL, 0);
235 break;
236 default:
237 trace_seq_puts(s, "map what?\n");
238 break;
239 }
240
241 return trace_handle_return(s);
242}
243
244static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
245{
246 struct trace_entry *entry = iter->ent;
247 struct print_entry *print;
248 const char *msg;
249 struct trace_seq *s = &iter->seq;
250 unsigned long long t = ns2usecs(iter->ts);
251 unsigned long usec_rem = do_div(t, USEC_PER_SEC);
252 unsigned secs = (unsigned long)t;
253
254 trace_assign_type(print, entry);
255 msg = print->buf;
256
257 /* The trailing newline must be in the message. */
258 trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg);
259
260 return trace_handle_return(s);
261}
262
263static enum print_line_t mmio_print_line(struct trace_iterator *iter)
264{
265 switch (iter->ent->type) {
266 case TRACE_MMIO_RW:
267 return mmio_print_rw(iter);
268 case TRACE_MMIO_MAP:
269 return mmio_print_map(iter);
270 case TRACE_PRINT:
271 return mmio_print_mark(iter);
272 default:
273 return TRACE_TYPE_HANDLED; /* ignore unknown entries */
274 }
275}
276
277static struct tracer mmio_tracer __read_mostly =
278{
279 .name = "mmiotrace",
280 .init = mmio_trace_init,
281 .reset = mmio_trace_reset,
282 .start = mmio_trace_start,
283 .pipe_open = mmio_pipe_open,
284 .close = mmio_close,
285 .pipe_close = mmio_close,
286 .read = mmio_read,
287 .print_line = mmio_print_line,
288 .noboot = true,
289};
290
291__init static int init_mmio_trace(void)
292{
293 return register_tracer(&mmio_tracer);
294}
295device_initcall(init_mmio_trace);
296
297static void __trace_mmiotrace_rw(struct trace_array *tr,
298 struct mmiotrace_rw *rw)
299{
300 struct trace_buffer *buffer;
301 struct ring_buffer_event *event;
302 struct trace_mmiotrace_rw *entry;
303 unsigned int trace_ctx;
304
305 if (!tr)
306 return;
307
308 buffer = tr->array_buffer.buffer;
309 trace_ctx = tracing_gen_ctx_flags(0);
310 event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW,
311 sizeof(*entry), trace_ctx);
312 if (!event) {
313 atomic_inc(&dropped_count);
314 return;
315 }
316 entry = ring_buffer_event_data(event);
317 entry->rw = *rw;
318
319 trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
320}
321
322void mmio_trace_rw(struct mmiotrace_rw *rw)
323{
324 struct trace_array *tr = mmio_trace_array;
325 __trace_mmiotrace_rw(tr, rw);
326}
327
328static void __trace_mmiotrace_map(struct trace_array *tr,
329 struct mmiotrace_map *map)
330{
331 struct trace_buffer *buffer;
332 struct ring_buffer_event *event;
333 struct trace_mmiotrace_map *entry;
334 unsigned int trace_ctx;
335
336 if (!tr)
337 return;
338
339 buffer = tr->array_buffer.buffer;
340 trace_ctx = tracing_gen_ctx_flags(0);
341 event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP,
342 sizeof(*entry), trace_ctx);
343 if (!event) {
344 atomic_inc(&dropped_count);
345 return;
346 }
347 entry = ring_buffer_event_data(event);
348 entry->map = *map;
349
350 trace_buffer_unlock_commit(tr, buffer, event, trace_ctx);
351}
352
353void mmio_trace_mapping(struct mmiotrace_map *map)
354{
355 struct trace_array *tr = mmio_trace_array;
356 __trace_mmiotrace_map(tr, map);
357}
358
359int mmio_trace_printk(const char *fmt, va_list args)
360{
361 return trace_vprintk(0, fmt, args);
362}