summaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_mmiotrace.c
blob: fd3c8aae55e5a17464e4ee7dbd82d77f0a831ea3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
/*
 * Memory mapped I/O tracing
 *
 * Copyright (C) 2008 Pekka Paalanen <pq@iki.fi>
 */

#define DEBUG 1

#include <linux/kernel.h>
#include <linux/mmiotrace.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/time.h>

#include <linux/atomic.h>

#include "trace.h"
#include "trace_output.h"

struct header_iter {
	struct pci_dev *dev;
};

static struct trace_array *mmio_trace_array;
static bool overrun_detected;
static unsigned long prev_overruns;
static atomic_t dropped_count;

static void mmio_reset_data(struct trace_array *tr)
{
	overrun_detected = false;
	prev_overruns = 0;

	tracing_reset_online_cpus(tr);
}

static int mmio_trace_init(struct trace_array *tr)
{
	pr_debug("in %s\n", __func__);
	mmio_trace_array = tr;

	mmio_reset_data(tr);
	enable_mmiotrace();
	return 0;
}

static void mmio_trace_reset(struct trace_array *tr)
{
	pr_debug("in %s\n", __func__);

	disable_mmiotrace();
	mmio_reset_data(tr);
	mmio_trace_array = NULL;
}

static void mmio_trace_start(struct trace_array *tr)
{
	pr_debug("in %s\n", __func__);
	mmio_reset_data(tr);
}

static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
{
	int ret = 0;
	int i;
	resource_size_t start, end;
	const struct pci_driver *drv = pci_dev_driver(dev);

	/* XXX: incomplete checks for trace_seq_printf() return value */
	ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
				dev->bus->number, dev->devfn,
				dev->vendor, dev->device, dev->irq);
	/*
	 * XXX: is pci_resource_to_user() appropriate, since we are
	 * supposed to interpret the __ioremap() phys_addr argument based on
	 * these printed values?
	 */
	for (i = 0; i < 7; i++) {
		pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
		ret += trace_seq_printf(s, " %llx",
			(unsigned long long)(start |
			(dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
	}
	for (i = 0; i < 7; i++) {
		pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
		ret += trace_seq_printf(s, " %llx",
			dev->resource[i].start < dev->resource[i].end ?
			(unsigned long long)(end - start) + 1 : 0);
	}
	if (drv)
		ret += trace_seq_printf(s, " %s\n", drv->name);
	else
		ret += trace_seq_printf(s, " \n");
	return ret;
}

static void destroy_header_iter(struct header_iter *hiter)
{
	if (!hiter)
		return;
	pci_dev_put(hiter->dev);
	kfree(hiter);
}

static void mmio_pipe_open(struct trace_iterator *iter)
{
	struct header_iter *hiter;
	struct trace_seq *s = &iter->seq;

	trace_seq_printf(s, "VERSION 20070824\n");

	hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);
	if (!hiter)
		return;

	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
	iter->private = hiter;
}

/* XXX: This is not called when the pipe is closed! */
static void mmio_close(struct trace_iterator *iter)
{
	struct header_iter *hiter = iter->private;
	destroy_header_iter(hiter);
	iter->private = NULL;
}

static unsigned long count_overruns(struct trace_iterator *iter)
{
	unsigned long cnt = atomic_xchg(&dropped_count, 0);
	unsigned long over = ring_buffer_overruns(iter->tr->buffer);

	if (over > prev_overruns)
		cnt += over - prev_overruns;
	prev_overruns = over;
	return cnt;
}

static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
				char __user *ubuf, size_t cnt, loff_t *ppos)
{
	ssize_t ret;
	struct header_iter *hiter = iter->private;
	struct trace_seq *s = &iter->seq;
	unsigned long n;

	n = count_overruns(iter);
	if (n) {
		/* XXX: This is later than where events were lost. */
		trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
		if (!overrun_detected)
			pr_warning("mmiotrace has lost events.\n");
		overrun_detected = true;
		goto print_out;
	}

	if (!hiter)
		return 0;

	mmio_print_pcidev(s, hiter->dev);
	hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);

	if (!hiter->dev) {
		destroy_header_iter(hiter);
		iter->private = NULL;
	}

print_out:
	ret = trace_seq_to_user(s, ubuf, cnt);
	return (ret == -EBUSY) ? 0 : ret;
}

static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
{
	struct trace_entry *entry = iter->ent;
	struct trace_mmiotrace_rw *field;
	struct mmiotrace_rw *rw;
	struct trace_seq *s	= &iter->seq;
	unsigned long long t	= ns2usecs(iter->ts);
	unsigned long usec_rem	= do_div(t, USEC_PER_SEC);
	unsigned secs		= (unsigned long)t;
	int ret = 1;

	trace_assign_type(field, entry);
	rw = &field->rw;

	switch (rw->opcode) {
	case MMIO_READ:
		ret = trace_seq_printf(s,
			"R %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
			rw->width, secs, usec_rem, rw->map_id,
			(unsigned long long)rw->phys,
			rw->value, rw->pc, 0);
		break;
	case MMIO_WRITE:
		ret = trace_seq_printf(s,
			"W %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
			rw->width, secs, usec_rem, rw->map_id,
			(unsigned long long)rw->phys,
			rw->value, rw->pc, 0);
		break;
	case MMIO_UNKNOWN_OP:
		ret = trace_seq_printf(s,
			"UNKNOWN %u.%06lu %d 0x%llx %02lx,%02lx,"
			"%02lx 0x%lx %d\n",
			secs, usec_rem, rw->map_id,
			(unsigned long long)rw->phys,
			(rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
			(rw->value >> 0) & 0xff, rw->pc, 0);
		break;
	default:
		ret = trace_seq_printf(s, "rw what?\n");
		break;
	}
	if (ret)
		return TRACE_TYPE_HANDLED;
	return TRACE_TYPE_PARTIAL_LINE;
}

static enum print_line_t mmio_print_map(struct trace_iterator *iter)
{
	struct trace_entry *entry = iter->ent;
	struct trace_mmiotrace_map *field;
	struct mmiotrace_map *m;
	struct trace_seq *s	= &iter->seq;
	unsigned long long t	= ns2usecs(iter->ts);
	unsigned long usec_rem	= do_div(t, USEC_PER_SEC);
	unsigned secs		= (unsigned long)t;
	int ret;

	trace_assign_type(field, entry);
	m = &field->map;

	switch (m->opcode) {
	case MMIO_PROBE:
		ret = trace_seq_printf(s,
			"MAP %u.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
			secs, usec_rem, m->map_id,
			(unsigned long long)m->phys, m->virt, m->len,
			0UL, 0);
		break;
	case MMIO_UNPROBE:
		ret = trace_seq_printf(s,
			"UNMAP %u.%06lu %d 0x%lx %d\n",
			secs, usec_rem, m->map_id, 0UL, 0);
		break;
	default:
		ret = trace_seq_printf(s, "map what?\n");
		break;
	}
	if (ret)
		return TRACE_TYPE_HANDLED;
	return TRACE_TYPE_PARTIAL_LINE;
}

static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
{
	struct trace_entry *entry = iter->ent;
	struct print_entry *print = (struct print_entry *)entry;
	const char *msg		= print->buf;
	struct trace_seq *s	= &iter->seq;
	unsigned long long t	= ns2usecs(iter->ts);
	unsigned long usec_rem	= do_div(t, USEC_PER_SEC);
	unsigned secs		= (unsigned long)t;
	int ret;

	/* The trailing newline must be in the message. */
	ret = trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t mmio_print_line(struct trace_iterator *iter)
{
	switch (iter->ent->type) {
	case TRACE_MMIO_RW:
		return mmio_print_rw(iter);
	case TRACE_MMIO_MAP:
		return mmio_print_map(iter);
	case TRACE_PRINT:
		return mmio_print_mark(iter);
	default:
		return TRACE_TYPE_HANDLED; /* ignore unknown entries */
	}
}

static struct tracer mmio_tracer __read_mostly =
{
	.name		= "mmiotrace",
	.init		= mmio_trace_init,
	.reset		= mmio_trace_reset,
	.start		= mmio_trace_start,
	.pipe_open	= mmio_pipe_open,
	.close		= mmio_close,
	.read		= mmio_read,
	.print_line	= mmio_print_line,
};

__init static int init_mmio_trace(void)
{
	return register_tracer(&mmio_tracer);
}
device_initcall(init_mmio_trace);

static void __trace_mmiotrace_rw(struct trace_array *tr,
				struct trace_array_cpu *data,
				struct mmiotrace_rw *rw)
{
	struct ftrace_event_call *call = &event_mmiotrace_rw;
	struct ring_buffer *buffer = tr->buffer;
	struct ring_buffer_event *event;
	struct trace_mmiotrace_rw *entry;
	int pc = preempt_count();

	event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW,
					  sizeof(*entry), 0, pc);
	if (!event) {
		atomic_inc(&dropped_count);
		return;
	}
	entry	= ring_buffer_event_data(event);
	entry->rw			= *rw;

	if (!filter_check_discard(call, entry, buffer, event))
		trace_buffer_unlock_commit(buffer, event, 0, pc);
}

void mmio_trace_rw(struct mmiotrace_rw *rw)
{
	struct trace_array *tr = mmio_trace_array;
	struct trace_array_cpu *data = tr->data[smp_processor_id()];
	__trace_mmiotrace_rw(tr, data, rw);
}

static void __trace_mmiotrace_map(struct trace_array *tr,
				struct trace_array_cpu *data,
				struct mmiotrace_map *map)
{
	struct ftrace_event_call *call = &event_mmiotrace_map;
	struct ring_buffer *buffer = tr->buffer;
	struct ring_buffer_event *event;
	struct trace_mmiotrace_map *entry;
	int pc = preempt_count();

	event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP,
					  sizeof(*entry), 0, pc);
	if (!event) {
		atomic_inc(&dropped_count);
		return;
	}
	entry	= ring_buffer_event_data(event);
	entry->map			= *map;

	if (!filter_check_discard(call, entry, buffer, event))
		trace_buffer_unlock_commit(buffer, event, 0, pc);
}

void mmio_trace_mapping(struct mmiotrace_map *map)
{
	struct trace_array *tr = mmio_trace_array;
	struct trace_array_cpu *data;

	preempt_disable();
	data = tr->data[smp_processor_id()];
	__trace_mmiotrace_map(tr, data, map);
	preempt_enable();
}

int mmio_trace_printk(const char *fmt, va_list args)
{
	return trace_vprintk(0, fmt, args);
}
OpenPOWER on IntegriCloud