Root/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#include <linux/slab.h>
13#include <linux/time.h>
14
15#include <asm/atomic.h>
16
17#include "trace.h"
18#include "trace_output.h"
19
20struct header_iter {
21    struct pci_dev *dev;
22};
23
24static struct trace_array *mmio_trace_array;
25static bool overrun_detected;
26static unsigned long prev_overruns;
27static atomic_t dropped_count;
28
29static void mmio_reset_data(struct trace_array *tr)
30{
31    overrun_detected = false;
32    prev_overruns = 0;
33
34    tracing_reset_online_cpus(tr);
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 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_printf(s, " \n");
94    return ret;
95}
96
97static 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
105static 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_printf(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! */
121static 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
128static 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->tr->buffer);
132
133    if (over > prev_overruns)
134        cnt += over - prev_overruns;
135    prev_overruns = over;
136    return cnt;
137}
138
139static 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
168print_out:
169    ret = trace_seq_to_user(s, ubuf, cnt);
170    return (ret == -EBUSY) ? 0 : ret;
171}
172
173static 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_printf(s, "rw what?\n");
213        break;
214    }
215    if (ret)
216        return TRACE_TYPE_HANDLED;
217    return TRACE_TYPE_PARTIAL_LINE;
218}
219
220static 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_printf(s, "map what?\n");
249        break;
250    }
251    if (ret)
252        return TRACE_TYPE_HANDLED;
253    return TRACE_TYPE_PARTIAL_LINE;
254}
255
256static 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
275static 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
289static 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}
305device_initcall(init_mmio_trace);
306
307static 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->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
330void mmio_trace_rw(struct mmiotrace_rw *rw)
331{
332    struct trace_array *tr = mmio_trace_array;
333    struct trace_array_cpu *data = tr->data[smp_processor_id()];
334    __trace_mmiotrace_rw(tr, data, rw);
335}
336
337static 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->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
360void 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 = tr->data[smp_processor_id()];
367    __trace_mmiotrace_map(tr, data, map);
368    preempt_enable();
369}
370
371int mmio_trace_printk(const char *fmt, va_list args)
372{
373    return trace_vprintk(0, fmt, args);
374}
375

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9



interactive