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
  13 #include "trace.h"
  14
  15 struct header_iter {
  16         struct pci_dev *dev;
  17 };
  18
  19 static struct trace_array *mmio_trace_array;
  20 static bool overrun_detected;
  21
  22 static void mmio_reset_data(struct trace_array *tr)
  23 {
  24         int cpu;
  25
  26         overrun_detected = false;
  27         tr->time_start = ftrace_now(tr->cpu);
  28
  29         for_each_online_cpu(cpu)
  30                 tracing_reset(tr, cpu);
  31 }
  32
  33 static void mmio_trace_init(struct trace_array *tr)
  34 {
  35         pr_debug("in %s\n", __func__);
  36         mmio_trace_array = tr;
  37
  38         mmio_reset_data(tr);
  39         enable_mmiotrace();
  40 }
  41
  42 static void mmio_trace_reset(struct trace_array *tr)
  43 {
  44         pr_debug("in %s\n", __func__);
  45
  46         disable_mmiotrace();
  47         mmio_reset_data(tr);
  48         mmio_trace_array = NULL;
  49 }
  50
  51 static void mmio_trace_start(struct trace_array *tr)
  52 {
  53         pr_debug("in %s\n", __func__);
  54         mmio_reset_data(tr);
  55 }
  56
  57 static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev)
  58 {
  59         int ret = 0;
  60         int i;
  61         resource_size_t start, end;
  62         const struct pci_driver *drv = pci_dev_driver(dev);
  63
  64         /* XXX: incomplete checks for trace_seq_printf() return value */
  65         ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x",
  66                                 dev->bus->number, dev->devfn,
  67                                 dev->vendor, dev->device, dev->irq);
  68         /*
  69          * XXX: is pci_resource_to_user() appropriate, since we are
  70          * supposed to interpret the __ioremap() phys_addr argument based on
  71          * these printed values?
  72          */
  73         for (i = 0; i < 7; i++) {
  74                 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
  75                 ret += trace_seq_printf(s, " %llx",
  76                         (unsigned long long)(start |
  77                         (dev->resource[i].flags & PCI_REGION_FLAG_MASK)));
  78         }
  79         for (i = 0; i < 7; i++) {
  80                 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end);
  81                 ret += trace_seq_printf(s, " %llx",
  82                         dev->resource[i].start < dev->resource[i].end ?
  83                         (unsigned long long)(end - start) + 1 : 0);
  84         }
  85         if (drv)
  86                 ret += trace_seq_printf(s, " %s\n", drv->name);
  87         else
  88                 ret += trace_seq_printf(s, " \n");
  89         return ret;
  90 }
  91
  92 static void destroy_header_iter(struct header_iter *hiter)
  93 {
  94         if (!hiter)
  95                 return;
  96         pci_dev_put(hiter->dev);
  97         kfree(hiter);
  98 }
  99
 100 static void mmio_pipe_open(struct trace_iterator *iter)
 101 {
 102         struct header_iter *hiter;
 103         struct trace_seq *s = &iter->seq;
 104
 105         trace_seq_printf(s, "VERSION 20070824\n");
 106
 107         hiter = kzalloc(sizeof(*hiter), GFP_KERNEL);
 108         if (!hiter)
 109                 return;
 110
 111         hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL);
 112         iter->private = hiter;
 113 }
 114
 115 /* XXX: This is not called when the pipe is closed! */
 116 static void mmio_close(struct trace_iterator *iter)
 117 {
 118         struct header_iter *hiter = iter->private;
 119         destroy_header_iter(hiter);
 120         iter->private = NULL;
 121 }
 122
 123 static unsigned long count_overruns(struct trace_iterator *iter)
 124 {
 125         int cpu;
 126         unsigned long cnt = 0;
 127 /* FIXME: */
 128 #if 0
 129         for_each_online_cpu(cpu) {
 130                 cnt += iter->overrun[cpu];
 131                 iter->overrun[cpu] = 0;
 132         }
 133 #endif
 134         (void)cpu;
 135         return cnt;
 136 }
 137
 138 static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp,
 139                                 char __user *ubuf, size_t cnt, loff_t *ppos)
 140 {
 141         ssize_t ret;
 142         struct header_iter *hiter = iter->private;
 143         struct trace_seq *s = &iter->seq;
 144         unsigned long n;
 145
 146         n = count_overruns(iter);
 147         if (n) {
 148                 /* XXX: This is later than where events were lost. */
 149                 trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n);
 150                 if (!overrun_detected)
 151                         pr_warning("mmiotrace has lost events.\n");
 152                 overrun_detected = true;
 153                 goto print_out;
 154         }
 155
 156         if (!hiter)
 157                 return 0;
 158
 159         mmio_print_pcidev(s, hiter->dev);
 160         hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev);
 161
 162         if (!hiter->dev) {
 163                 destroy_header_iter(hiter);
 164                 iter->private = NULL;
 165         }
 166
 167 print_out:
 168         ret = trace_seq_to_user(s, ubuf, cnt);
 169         return (ret == -EBUSY) ? 0 : ret;
 170 }
 171
 172 static enum print_line_t mmio_print_rw(struct trace_iterator *iter)
 173 {
 174         struct trace_entry *entry = iter->ent;
 175         struct trace_mmiotrace_rw *field;
 176         struct mmiotrace_rw *rw;
 177         struct trace_seq *s     = &iter->seq;
 178         unsigned long long t    = ns2usecs(iter->ts);
 179         unsigned long usec_rem  = do_div(t, 1000000ULL);
 180         unsigned secs           = (unsigned long)t;
 181         int ret = 1;
 182
 183         trace_assign_type(field, entry);
 184         rw = &field->rw;
 185
 186         switch (rw->opcode) {
 187         case MMIO_READ:
 188                 ret = trace_seq_printf(s,
 189                         "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
 190                         rw->width, secs, usec_rem, rw->map_id,
 191                         (unsigned long long)rw->phys,
 192                         rw->value, rw->pc, 0);
 193                 break;
 194         case MMIO_WRITE:
 195                 ret = trace_seq_printf(s,
 196                         "W %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n",
 197                         rw->width, secs, usec_rem, rw->map_id,
 198                         (unsigned long long)rw->phys,
 199                         rw->value, rw->pc, 0);
 200                 break;
 201         case MMIO_UNKNOWN_OP:
 202                 ret = trace_seq_printf(s,
 203                         "UNKNOWN %lu.%06lu %d 0x%llx %02x,%02x,%02x 0x%lx %d\n",
 204                         secs, usec_rem, rw->map_id,
 205                         (unsigned long long)rw->phys,
 206                         (rw->value >> 16) & 0xff, (rw->value >> 8) & 0xff,
 207                         (rw->value >> 0) & 0xff, rw->pc, 0);
 208                 break;
 209         default:
 210                 ret = trace_seq_printf(s, "rw what?\n");
 211                 break;
 212         }
 213         if (ret)
 214                 return TRACE_TYPE_HANDLED;
 215         return TRACE_TYPE_PARTIAL_LINE;
 216 }
 217
 218 static enum print_line_t mmio_print_map(struct trace_iterator *iter)
 219 {
 220         struct trace_entry *entry = iter->ent;
 221         struct trace_mmiotrace_map *field;
 222         struct mmiotrace_map *m;
 223         struct trace_seq *s     = &iter->seq;
 224         unsigned long long t    = ns2usecs(iter->ts);
 225         unsigned long usec_rem  = do_div(t, 1000000ULL);
 226         unsigned secs           = (unsigned long)t;
 227         int ret;
 228
 229         trace_assign_type(field, entry);
 230         m = &field->map;
 231
 232         switch (m->opcode) {
 233         case MMIO_PROBE:
 234                 ret = trace_seq_printf(s,
 235                         "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n",
 236                         secs, usec_rem, m->map_id,
 237                         (unsigned long long)m->phys, m->virt, m->len,
 238                         0UL, 0);
 239                 break;
 240         case MMIO_UNPROBE:
 241                 ret = trace_seq_printf(s,
 242                         "UNMAP %lu.%06lu %d 0x%lx %d\n",
 243                         secs, usec_rem, m->map_id, 0UL, 0);
 244                 break;
 245         default:
 246                 ret = trace_seq_printf(s, "map what?\n");
 247                 break;
 248         }
 249         if (ret)
 250                 return TRACE_TYPE_HANDLED;
 251         return TRACE_TYPE_PARTIAL_LINE;
 252 }
 253
 254 static enum print_line_t mmio_print_mark(struct trace_iterator *iter)
 255 {
 256         struct trace_entry *entry = iter->ent;
 257         struct print_entry *print = (struct print_entry *)entry;
 258         const char *msg         = print->buf;
 259         struct trace_seq *s     = &iter->seq;
 260         unsigned long long t    = ns2usecs(iter->ts);
 261         unsigned long usec_rem  = do_div(t, 1000000ULL);
 262         unsigned secs           = (unsigned long)t;
 263         int ret;
 264
 265         /* The trailing newline must be in the message. */
 266         ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg);
 267         if (!ret)
 268                 return TRACE_TYPE_PARTIAL_LINE;
 269
 270         if (entry->flags & TRACE_FLAG_CONT)
 271                 trace_seq_print_cont(s, iter);
 272
 273         return TRACE_TYPE_HANDLED;
 274 }
 275
 276 static enum print_line_t mmio_print_line(struct trace_iterator *iter)
 277 {
 278         switch (iter->ent->type) {
 279         case TRACE_MMIO_RW:
 280                 return mmio_print_rw(iter);
 281         case TRACE_MMIO_MAP:
 282                 return mmio_print_map(iter);
 283         case TRACE_PRINT:
 284                 return mmio_print_mark(iter);
 285         default:
 286                 return TRACE_TYPE_HANDLED; /* ignore unknown entries */
 287         }
 288 }
 289
 290 static struct tracer mmio_tracer __read_mostly =
 291 {
 292         .name           = "mmiotrace",
 293         .init           = mmio_trace_init,
 294         .reset          = mmio_trace_reset,
 295         .start          = mmio_trace_start,
 296         .pipe_open      = mmio_pipe_open,
 297         .close          = mmio_close,
 298         .read           = mmio_read,
 299         .print_line     = mmio_print_line,
 300 };
 301
 302 __init static int init_mmio_trace(void)
 303 {
 304         return register_tracer(&mmio_tracer);
 305 }
 306 device_initcall(init_mmio_trace);
 307
 308 static void __trace_mmiotrace_rw(struct trace_array *tr,
 309                                 struct trace_array_cpu *data,
 310                                 struct mmiotrace_rw *rw)
 311 {
 312         struct ring_buffer_event *event;
 313         struct trace_mmiotrace_rw *entry;
 314         unsigned long irq_flags;
 315
 316         event   = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
 317                                            &irq_flags);
 318         if (!event)
 319                 return;
 320         entry   = ring_buffer_event_data(event);
 321         tracing_generic_entry_update(&entry->ent, 0, preempt_count());
 322         entry->ent.type                 = TRACE_MMIO_RW;
 323         entry->rw                       = *rw;
 324         ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 325
 326         trace_wake_up();
 327 }
 328
 329 void mmio_trace_rw(struct mmiotrace_rw *rw)
 330 {
 331         struct trace_array *tr = mmio_trace_array;
 332         struct trace_array_cpu *data = tr->data[smp_processor_id()];
 333         __trace_mmiotrace_rw(tr, data, rw);
 334 }
 335
 336 static void __trace_mmiotrace_map(struct trace_array *tr,
 337                                 struct trace_array_cpu *data,
 338                                 struct mmiotrace_map *map)
 339 {
 340         struct ring_buffer_event *event;
 341         struct trace_mmiotrace_map *entry;
 342         unsigned long irq_flags;
 343
 344         event   = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry),
 345                                            &irq_flags);
 346         if (!event)
 347                 return;
 348         entry   = ring_buffer_event_data(event);
 349         tracing_generic_entry_update(&entry->ent, 0, preempt_count());
 350         entry->ent.type                 = TRACE_MMIO_MAP;
 351         entry->map                      = *map;
 352         ring_buffer_unlock_commit(tr->buffer, event, irq_flags);
 353
 354         trace_wake_up();
 355 }
 356
 357 void mmio_trace_mapping(struct mmiotrace_map *map)
 358 {
 359         struct trace_array *tr = mmio_trace_array;
 360         struct trace_array_cpu *data;
 361
 362         preempt_disable();
 363         data = tr->data[smp_processor_id()];
 364         __trace_mmiotrace_map(tr, data, map);
 365         preempt_enable();
 366 }
 367
 368 int mmio_trace_printk(const char *fmt, va_list args)
 369 {
 370         return trace_vprintk(0, fmt, args);
 371 }