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 <linux/atomic.h> 16 17 #include "trace.h" 18 #include "trace_output.h" 19 20 struct header_iter { 21 struct pci_dev *dev; 22 }; 23 24 static struct trace_array *mmio_trace_array; 25 static bool overrun_detected; 26 static unsigned long prev_overruns; 27 static atomic_t dropped_count; 28 29 static void mmio_reset_data(struct trace_array *tr) 30 { 31 overrun_detected = false; 32 prev_overruns = 0; 33 34 tracing_reset_online_cpus(&tr->trace_buffer); 35 } 36 37 static 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 47 static 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 56 static void mmio_trace_start(struct trace_array *tr) 57 { 58 pr_debug("in %s\n", __func__); 59 mmio_reset_data(tr); 60 } 61 62 static 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 /* 72 * XXX: is pci_resource_to_user() appropriate, since we are 73 * supposed to interpret the __ioremap() phys_addr argument based on 74 * these printed values? 75 */ 76 for (i = 0; i < 7; i++) { 77 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 78 trace_seq_printf(s, " %llx", 79 (unsigned long long)(start | 80 (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); 81 } 82 for (i = 0; i < 7; i++) { 83 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 84 trace_seq_printf(s, " %llx", 85 dev->resource[i].start < dev->resource[i].end ? 86 (unsigned long long)(end - start) + 1 : 0); 87 } 88 if (drv) 89 trace_seq_printf(s, " %s\n", drv->name); 90 else 91 trace_seq_puts(s, " \n"); 92 } 93 94 static void destroy_header_iter(struct header_iter *hiter) 95 { 96 if (!hiter) 97 return; 98 pci_dev_put(hiter->dev); 99 kfree(hiter); 100 } 101 102 static void mmio_pipe_open(struct trace_iterator *iter) 103 { 104 struct header_iter *hiter; 105 struct trace_seq *s = &iter->seq; 106 107 trace_seq_puts(s, "VERSION 20070824\n"); 108 109 hiter = kzalloc(sizeof(*hiter), GFP_KERNEL); 110 if (!hiter) 111 return; 112 113 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL); 114 iter->private = hiter; 115 } 116 117 /* XXX: This is not called when the pipe is closed! */ 118 static void mmio_close(struct trace_iterator *iter) 119 { 120 struct header_iter *hiter = iter->private; 121 destroy_header_iter(hiter); 122 iter->private = NULL; 123 } 124 125 static unsigned long count_overruns(struct trace_iterator *iter) 126 { 127 unsigned long cnt = atomic_xchg(&dropped_count, 0); 128 unsigned long over = ring_buffer_overruns(iter->trace_buffer->buffer); 129 130 if (over > prev_overruns) 131 cnt += over - prev_overruns; 132 prev_overruns = over; 133 return cnt; 134 } 135 136 static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp, 137 char __user *ubuf, size_t cnt, loff_t *ppos) 138 { 139 ssize_t ret; 140 struct header_iter *hiter = iter->private; 141 struct trace_seq *s = &iter->seq; 142 unsigned long n; 143 144 n = count_overruns(iter); 145 if (n) { 146 /* XXX: This is later than where events were lost. */ 147 trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n); 148 if (!overrun_detected) 149 pr_warning("mmiotrace has lost events.\n"); 150 overrun_detected = true; 151 goto print_out; 152 } 153 154 if (!hiter) 155 return 0; 156 157 mmio_print_pcidev(s, hiter->dev); 158 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev); 159 160 if (!hiter->dev) { 161 destroy_header_iter(hiter); 162 iter->private = NULL; 163 } 164 165 print_out: 166 ret = trace_seq_to_user(s, ubuf, cnt); 167 return (ret == -EBUSY) ? 0 : ret; 168 } 169 170 static enum print_line_t mmio_print_rw(struct trace_iterator *iter) 171 { 172 struct trace_entry *entry = iter->ent; 173 struct trace_mmiotrace_rw *field; 174 struct mmiotrace_rw *rw; 175 struct trace_seq *s = &iter->seq; 176 unsigned long long t = ns2usecs(iter->ts); 177 unsigned long usec_rem = do_div(t, USEC_PER_SEC); 178 unsigned secs = (unsigned long)t; 179 180 trace_assign_type(field, entry); 181 rw = &field->rw; 182 183 switch (rw->opcode) { 184 case MMIO_READ: 185 trace_seq_printf(s, 186 "R %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", 187 rw->width, secs, usec_rem, rw->map_id, 188 (unsigned long long)rw->phys, 189 rw->value, rw->pc, 0); 190 break; 191 case MMIO_WRITE: 192 trace_seq_printf(s, 193 "W %d %u.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", 194 rw->width, secs, usec_rem, rw->map_id, 195 (unsigned long long)rw->phys, 196 rw->value, rw->pc, 0); 197 break; 198 case MMIO_UNKNOWN_OP: 199 trace_seq_printf(s, 200 "UNKNOWN %u.%06lu %d 0x%llx %02lx,%02lx," 201 "%02lx 0x%lx %d\n", 202 secs, usec_rem, rw->map_id, 203 (unsigned long long)rw->phys, 204 (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff, 205 (rw->value >> 0) & 0xff, rw->pc, 0); 206 break; 207 default: 208 trace_seq_puts(s, "rw what?\n"); 209 break; 210 } 211 212 return trace_handle_return(s); 213 } 214 215 static enum print_line_t mmio_print_map(struct trace_iterator *iter) 216 { 217 struct trace_entry *entry = iter->ent; 218 struct trace_mmiotrace_map *field; 219 struct mmiotrace_map *m; 220 struct trace_seq *s = &iter->seq; 221 unsigned long long t = ns2usecs(iter->ts); 222 unsigned long usec_rem = do_div(t, USEC_PER_SEC); 223 unsigned secs = (unsigned long)t; 224 225 trace_assign_type(field, entry); 226 m = &field->map; 227 228 switch (m->opcode) { 229 case MMIO_PROBE: 230 trace_seq_printf(s, 231 "MAP %u.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", 232 secs, usec_rem, m->map_id, 233 (unsigned long long)m->phys, m->virt, m->len, 234 0UL, 0); 235 break; 236 case MMIO_UNPROBE: 237 trace_seq_printf(s, 238 "UNMAP %u.%06lu %d 0x%lx %d\n", 239 secs, usec_rem, m->map_id, 0UL, 0); 240 break; 241 default: 242 trace_seq_puts(s, "map what?\n"); 243 break; 244 } 245 246 return trace_handle_return(s); 247 } 248 249 static enum print_line_t mmio_print_mark(struct trace_iterator *iter) 250 { 251 struct trace_entry *entry = iter->ent; 252 struct print_entry *print = (struct print_entry *)entry; 253 const char *msg = print->buf; 254 struct trace_seq *s = &iter->seq; 255 unsigned long long t = ns2usecs(iter->ts); 256 unsigned long usec_rem = do_div(t, USEC_PER_SEC); 257 unsigned secs = (unsigned long)t; 258 259 /* The trailing newline must be in the message. */ 260 trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg); 261 262 return trace_handle_return(s); 263 } 264 265 static enum print_line_t mmio_print_line(struct trace_iterator *iter) 266 { 267 switch (iter->ent->type) { 268 case TRACE_MMIO_RW: 269 return mmio_print_rw(iter); 270 case TRACE_MMIO_MAP: 271 return mmio_print_map(iter); 272 case TRACE_PRINT: 273 return mmio_print_mark(iter); 274 default: 275 return TRACE_TYPE_HANDLED; /* ignore unknown entries */ 276 } 277 } 278 279 static struct tracer mmio_tracer __read_mostly = 280 { 281 .name = "mmiotrace", 282 .init = mmio_trace_init, 283 .reset = mmio_trace_reset, 284 .start = mmio_trace_start, 285 .pipe_open = mmio_pipe_open, 286 .close = mmio_close, 287 .read = mmio_read, 288 .print_line = mmio_print_line, 289 }; 290 291 __init static int init_mmio_trace(void) 292 { 293 return register_tracer(&mmio_tracer); 294 } 295 device_initcall(init_mmio_trace); 296 297 static void __trace_mmiotrace_rw(struct trace_array *tr, 298 struct trace_array_cpu *data, 299 struct mmiotrace_rw *rw) 300 { 301 struct trace_event_call *call = &event_mmiotrace_rw; 302 struct ring_buffer *buffer = tr->trace_buffer.buffer; 303 struct ring_buffer_event *event; 304 struct trace_mmiotrace_rw *entry; 305 int pc = preempt_count(); 306 307 event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_RW, 308 sizeof(*entry), 0, pc); 309 if (!event) { 310 atomic_inc(&dropped_count); 311 return; 312 } 313 entry = ring_buffer_event_data(event); 314 entry->rw = *rw; 315 316 if (!call_filter_check_discard(call, entry, buffer, event)) 317 trace_buffer_unlock_commit(tr, buffer, event, 0, pc); 318 } 319 320 void mmio_trace_rw(struct mmiotrace_rw *rw) 321 { 322 struct trace_array *tr = mmio_trace_array; 323 struct trace_array_cpu *data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id()); 324 __trace_mmiotrace_rw(tr, data, rw); 325 } 326 327 static void __trace_mmiotrace_map(struct trace_array *tr, 328 struct trace_array_cpu *data, 329 struct mmiotrace_map *map) 330 { 331 struct trace_event_call *call = &event_mmiotrace_map; 332 struct ring_buffer *buffer = tr->trace_buffer.buffer; 333 struct ring_buffer_event *event; 334 struct trace_mmiotrace_map *entry; 335 int pc = preempt_count(); 336 337 event = trace_buffer_lock_reserve(buffer, TRACE_MMIO_MAP, 338 sizeof(*entry), 0, pc); 339 if (!event) { 340 atomic_inc(&dropped_count); 341 return; 342 } 343 entry = ring_buffer_event_data(event); 344 entry->map = *map; 345 346 if (!call_filter_check_discard(call, entry, buffer, event)) 347 trace_buffer_unlock_commit(tr, buffer, event, 0, pc); 348 } 349 350 void mmio_trace_mapping(struct mmiotrace_map *map) 351 { 352 struct trace_array *tr = mmio_trace_array; 353 struct trace_array_cpu *data; 354 355 preempt_disable(); 356 data = per_cpu_ptr(tr->trace_buffer.data, smp_processor_id()); 357 __trace_mmiotrace_map(tr, data, map); 358 preempt_enable(); 359 } 360 361 int mmio_trace_printk(const char *fmt, va_list args) 362 { 363 return trace_vprintk(0, fmt, args); 364 } 365