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 | #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 | |
19 | struct { |
20 | struct pci_dev *; |
21 | }; |
22 | |
23 | static struct trace_array *mmio_trace_array; |
24 | static bool overrun_detected; |
25 | static unsigned long prev_overruns; |
26 | static atomic_t dropped_count; |
27 | |
28 | static void mmio_reset_data(struct trace_array *tr) |
29 | { |
30 | overrun_detected = false; |
31 | prev_overruns = 0; |
32 | |
33 | tracing_reset_online_cpus(buf: &tr->array_buffer); |
34 | } |
35 | |
36 | static int mmio_trace_init(struct trace_array *tr) |
37 | { |
38 | pr_debug("in %s\n" , __func__); |
39 | mmio_trace_array = tr; |
40 | |
41 | mmio_reset_data(tr); |
42 | enable_mmiotrace(); |
43 | return 0; |
44 | } |
45 | |
46 | static void mmio_trace_reset(struct trace_array *tr) |
47 | { |
48 | pr_debug("in %s\n" , __func__); |
49 | |
50 | disable_mmiotrace(); |
51 | mmio_reset_data(tr); |
52 | mmio_trace_array = NULL; |
53 | } |
54 | |
55 | static void mmio_trace_start(struct trace_array *tr) |
56 | { |
57 | pr_debug("in %s\n" , __func__); |
58 | mmio_reset_data(tr); |
59 | } |
60 | |
61 | static void mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) |
62 | { |
63 | int i; |
64 | resource_size_t start, end; |
65 | const struct pci_driver *drv = pci_dev_driver(dev); |
66 | |
67 | trace_seq_printf(s, fmt: "PCIDEV %02x%02x %04x%04x %x" , |
68 | dev->bus->number, dev->devfn, |
69 | dev->vendor, dev->device, dev->irq); |
70 | for (i = 0; i < 7; i++) { |
71 | start = dev->resource[i].start; |
72 | trace_seq_printf(s, fmt: " %llx" , |
73 | (unsigned long long)(start | |
74 | (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); |
75 | } |
76 | for (i = 0; i < 7; i++) { |
77 | start = dev->resource[i].start; |
78 | end = dev->resource[i].end; |
79 | trace_seq_printf(s, fmt: " %llx" , |
80 | dev->resource[i].start < dev->resource[i].end ? |
81 | (unsigned long long)(end - start) + 1 : 0); |
82 | } |
83 | if (drv) |
84 | trace_seq_printf(s, fmt: " %s\n" , drv->name); |
85 | else |
86 | trace_seq_puts(s, str: " \n" ); |
87 | } |
88 | |
89 | static void (struct header_iter *hiter) |
90 | { |
91 | if (!hiter) |
92 | return; |
93 | pci_dev_put(dev: hiter->dev); |
94 | kfree(objp: hiter); |
95 | } |
96 | |
97 | static void mmio_pipe_open(struct trace_iterator *iter) |
98 | { |
99 | struct header_iter *hiter; |
100 | struct trace_seq *s = &iter->seq; |
101 | |
102 | trace_seq_puts(s, str: "VERSION 20070824\n" ); |
103 | |
104 | hiter = kzalloc(size: sizeof(*hiter), GFP_KERNEL); |
105 | if (!hiter) |
106 | return; |
107 | |
108 | hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL); |
109 | iter->private = hiter; |
110 | } |
111 | |
112 | /* XXX: This is not called when the pipe is closed! */ |
113 | static 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 | |
120 | static unsigned long count_overruns(struct trace_iterator *iter) |
121 | { |
122 | unsigned long cnt = atomic_xchg(v: &dropped_count, new: 0); |
123 | unsigned long over = ring_buffer_overruns(buffer: iter->array_buffer->buffer); |
124 | |
125 | if (over > prev_overruns) |
126 | cnt += over - prev_overruns; |
127 | prev_overruns = over; |
128 | return cnt; |
129 | } |
130 | |
131 | static 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, fmt: "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) |
150 | return 0; |
151 | |
152 | mmio_print_pcidev(s, dev: hiter->dev); |
153 | hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, from: hiter->dev); |
154 | |
155 | if (!hiter->dev) { |
156 | destroy_header_iter(hiter); |
157 | iter->private = NULL; |
158 | } |
159 | |
160 | print_out: |
161 | ret = trace_seq_to_user(s, ubuf, cnt); |
162 | return (ret == -EBUSY) ? 0 : ret; |
163 | } |
164 | |
165 | static 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(nsec: 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 | fmt: "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 | fmt: "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 | fmt: "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, str: "rw what?\n" ); |
204 | break; |
205 | } |
206 | |
207 | return trace_handle_return(s); |
208 | } |
209 | |
210 | static 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(nsec: 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 | fmt: "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 | fmt: "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, str: "map what?\n" ); |
238 | break; |
239 | } |
240 | |
241 | return trace_handle_return(s); |
242 | } |
243 | |
244 | static enum print_line_t mmio_print_mark(struct trace_iterator *iter) |
245 | { |
246 | struct trace_entry *entry = iter->ent; |
247 | struct print_entry *print = (struct print_entry *)entry; |
248 | const char *msg = print->buf; |
249 | struct trace_seq *s = &iter->seq; |
250 | unsigned long long t = ns2usecs(nsec: iter->ts); |
251 | unsigned long usec_rem = do_div(t, USEC_PER_SEC); |
252 | unsigned secs = (unsigned long)t; |
253 | |
254 | /* The trailing newline must be in the message. */ |
255 | trace_seq_printf(s, fmt: "MARK %u.%06lu %s" , secs, usec_rem, msg); |
256 | |
257 | return trace_handle_return(s); |
258 | } |
259 | |
260 | static enum print_line_t mmio_print_line(struct trace_iterator *iter) |
261 | { |
262 | switch (iter->ent->type) { |
263 | case TRACE_MMIO_RW: |
264 | return mmio_print_rw(iter); |
265 | case TRACE_MMIO_MAP: |
266 | return mmio_print_map(iter); |
267 | case TRACE_PRINT: |
268 | return mmio_print_mark(iter); |
269 | default: |
270 | return TRACE_TYPE_HANDLED; /* ignore unknown entries */ |
271 | } |
272 | } |
273 | |
274 | static struct tracer mmio_tracer __read_mostly = |
275 | { |
276 | .name = "mmiotrace" , |
277 | .init = mmio_trace_init, |
278 | .reset = mmio_trace_reset, |
279 | .start = mmio_trace_start, |
280 | .pipe_open = mmio_pipe_open, |
281 | .close = mmio_close, |
282 | .read = mmio_read, |
283 | .print_line = mmio_print_line, |
284 | .noboot = true, |
285 | }; |
286 | |
287 | __init static int init_mmio_trace(void) |
288 | { |
289 | return register_tracer(type: &mmio_tracer); |
290 | } |
291 | device_initcall(init_mmio_trace); |
292 | |
293 | static void __trace_mmiotrace_rw(struct trace_array *tr, |
294 | struct trace_array_cpu *data, |
295 | struct mmiotrace_rw *rw) |
296 | { |
297 | struct trace_event_call *call = &event_mmiotrace_rw; |
298 | struct trace_buffer *buffer = tr->array_buffer.buffer; |
299 | struct ring_buffer_event *event; |
300 | struct trace_mmiotrace_rw *entry; |
301 | unsigned int trace_ctx; |
302 | |
303 | trace_ctx = tracing_gen_ctx_flags(irqflags: 0); |
304 | event = trace_buffer_lock_reserve(buffer, type: TRACE_MMIO_RW, |
305 | len: sizeof(*entry), trace_ctx); |
306 | if (!event) { |
307 | atomic_inc(v: &dropped_count); |
308 | return; |
309 | } |
310 | entry = ring_buffer_event_data(event); |
311 | entry->rw = *rw; |
312 | |
313 | if (!call_filter_check_discard(call, rec: entry, buffer, event)) |
314 | trace_buffer_unlock_commit(tr, buffer, event, trace_ctx); |
315 | } |
316 | |
317 | void mmio_trace_rw(struct mmiotrace_rw *rw) |
318 | { |
319 | struct trace_array *tr = mmio_trace_array; |
320 | struct trace_array_cpu *data = per_cpu_ptr(tr->array_buffer.data, smp_processor_id()); |
321 | __trace_mmiotrace_rw(tr, data, rw); |
322 | } |
323 | |
324 | static void __trace_mmiotrace_map(struct trace_array *tr, |
325 | struct trace_array_cpu *data, |
326 | struct mmiotrace_map *map) |
327 | { |
328 | struct trace_event_call *call = &event_mmiotrace_map; |
329 | struct trace_buffer *buffer = tr->array_buffer.buffer; |
330 | struct ring_buffer_event *event; |
331 | struct trace_mmiotrace_map *entry; |
332 | unsigned int trace_ctx; |
333 | |
334 | trace_ctx = tracing_gen_ctx_flags(irqflags: 0); |
335 | event = trace_buffer_lock_reserve(buffer, type: TRACE_MMIO_MAP, |
336 | len: sizeof(*entry), trace_ctx); |
337 | if (!event) { |
338 | atomic_inc(v: &dropped_count); |
339 | return; |
340 | } |
341 | entry = ring_buffer_event_data(event); |
342 | entry->map = *map; |
343 | |
344 | if (!call_filter_check_discard(call, rec: entry, buffer, event)) |
345 | trace_buffer_unlock_commit(tr, buffer, event, trace_ctx); |
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->array_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(ip: 0, fmt, args); |
362 | } |
363 | |