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->data[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 if (tr->ctrl) { 38 mmio_reset_data(tr); 39 enable_mmiotrace(); 40 } 41 } 42 43 static void mmio_trace_reset(struct trace_array *tr) 44 { 45 pr_debug("in %s\n", __func__); 46 if (tr->ctrl) 47 disable_mmiotrace(); 48 mmio_reset_data(tr); 49 mmio_trace_array = NULL; 50 } 51 52 static void mmio_trace_ctrl_update(struct trace_array *tr) 53 { 54 pr_debug("in %s\n", __func__); 55 if (tr->ctrl) { 56 mmio_reset_data(tr); 57 enable_mmiotrace(); 58 } else { 59 disable_mmiotrace(); 60 } 61 } 62 63 static int mmio_print_pcidev(struct trace_seq *s, const struct pci_dev *dev) 64 { 65 int ret = 0; 66 int i; 67 resource_size_t start, end; 68 const struct pci_driver *drv = pci_dev_driver(dev); 69 70 /* XXX: incomplete checks for trace_seq_printf() return value */ 71 ret += trace_seq_printf(s, "PCIDEV %02x%02x %04x%04x %x", 72 dev->bus->number, dev->devfn, 73 dev->vendor, dev->device, dev->irq); 74 /* 75 * XXX: is pci_resource_to_user() appropriate, since we are 76 * supposed to interpret the __ioremap() phys_addr argument based on 77 * these printed values? 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 (unsigned long long)(start | 83 (dev->resource[i].flags & PCI_REGION_FLAG_MASK))); 84 } 85 for (i = 0; i < 7; i++) { 86 pci_resource_to_user(dev, i, &dev->resource[i], &start, &end); 87 ret += trace_seq_printf(s, " %llx", 88 dev->resource[i].start < dev->resource[i].end ? 89 (unsigned long long)(end - start) + 1 : 0); 90 } 91 if (drv) 92 ret += trace_seq_printf(s, " %s\n", drv->name); 93 else 94 ret += trace_seq_printf(s, " \n"); 95 return ret; 96 } 97 98 static void destroy_header_iter(struct header_iter *hiter) 99 { 100 if (!hiter) 101 return; 102 pci_dev_put(hiter->dev); 103 kfree(hiter); 104 } 105 106 static void mmio_pipe_open(struct trace_iterator *iter) 107 { 108 struct header_iter *hiter; 109 struct trace_seq *s = &iter->seq; 110 111 trace_seq_printf(s, "VERSION 20070824\n"); 112 113 hiter = kzalloc(sizeof(*hiter), GFP_KERNEL); 114 if (!hiter) 115 return; 116 117 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, NULL); 118 iter->private = hiter; 119 } 120 121 /* XXX: This is not called when the pipe is closed! */ 122 static void mmio_close(struct trace_iterator *iter) 123 { 124 struct header_iter *hiter = iter->private; 125 destroy_header_iter(hiter); 126 iter->private = NULL; 127 } 128 129 static unsigned long count_overruns(struct trace_iterator *iter) 130 { 131 int cpu; 132 unsigned long cnt = 0; 133 for_each_online_cpu(cpu) { 134 cnt += iter->overrun[cpu]; 135 iter->overrun[cpu] = 0; 136 } 137 return cnt; 138 } 139 140 static ssize_t mmio_read(struct trace_iterator *iter, struct file *filp, 141 char __user *ubuf, size_t cnt, loff_t *ppos) 142 { 143 ssize_t ret; 144 struct header_iter *hiter = iter->private; 145 struct trace_seq *s = &iter->seq; 146 unsigned long n; 147 148 n = count_overruns(iter); 149 if (n) { 150 /* XXX: This is later than where events were lost. */ 151 trace_seq_printf(s, "MARK 0.000000 Lost %lu events.\n", n); 152 if (!overrun_detected) 153 pr_warning("mmiotrace has lost events.\n"); 154 overrun_detected = true; 155 goto print_out; 156 } 157 158 if (!hiter) 159 return 0; 160 161 mmio_print_pcidev(s, hiter->dev); 162 hiter->dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, hiter->dev); 163 164 if (!hiter->dev) { 165 destroy_header_iter(hiter); 166 iter->private = NULL; 167 } 168 169 print_out: 170 ret = trace_seq_to_user(s, ubuf, cnt); 171 return (ret == -EBUSY) ? 0 : ret; 172 } 173 174 static int mmio_print_rw(struct trace_iterator *iter) 175 { 176 struct trace_entry *entry = iter->ent; 177 struct mmiotrace_rw *rw = &entry->mmiorw; 178 struct trace_seq *s = &iter->seq; 179 unsigned long long t = ns2usecs(entry->t); 180 unsigned long usec_rem = do_div(t, 1000000ULL); 181 unsigned secs = (unsigned long)t; 182 int ret = 1; 183 184 switch (entry->mmiorw.opcode) { 185 case MMIO_READ: 186 ret = trace_seq_printf(s, 187 "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", 188 rw->width, secs, usec_rem, rw->map_id, 189 (unsigned long long)rw->phys, 190 rw->value, rw->pc, 0); 191 break; 192 case MMIO_WRITE: 193 ret = trace_seq_printf(s, 194 "W %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", 195 rw->width, secs, usec_rem, rw->map_id, 196 (unsigned long long)rw->phys, 197 rw->value, rw->pc, 0); 198 break; 199 case MMIO_UNKNOWN_OP: 200 ret = trace_seq_printf(s, 201 "UNKNOWN %lu.%06lu %d 0x%llx %02x,%02x,%02x 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 ret = trace_seq_printf(s, "rw what?\n"); 209 break; 210 } 211 if (ret) 212 return 1; 213 return 0; 214 } 215 216 static int mmio_print_map(struct trace_iterator *iter) 217 { 218 struct trace_entry *entry = iter->ent; 219 struct mmiotrace_map *m = &entry->mmiomap; 220 struct trace_seq *s = &iter->seq; 221 unsigned long long t = ns2usecs(entry->t); 222 unsigned long usec_rem = do_div(t, 1000000ULL); 223 unsigned secs = (unsigned long)t; 224 int ret = 1; 225 226 switch (entry->mmiorw.opcode) { 227 case MMIO_PROBE: 228 ret = trace_seq_printf(s, 229 "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", 230 secs, usec_rem, m->map_id, 231 (unsigned long long)m->phys, m->virt, m->len, 232 0UL, 0); 233 break; 234 case MMIO_UNPROBE: 235 ret = trace_seq_printf(s, 236 "UNMAP %lu.%06lu %d 0x%lx %d\n", 237 secs, usec_rem, m->map_id, 0UL, 0); 238 break; 239 default: 240 ret = trace_seq_printf(s, "map what?\n"); 241 break; 242 } 243 if (ret) 244 return 1; 245 return 0; 246 } 247 248 /* return 0 to abort printing without consuming current entry in pipe mode */ 249 static int mmio_print_line(struct trace_iterator *iter) 250 { 251 switch (iter->ent->type) { 252 case TRACE_MMIO_RW: 253 return mmio_print_rw(iter); 254 case TRACE_MMIO_MAP: 255 return mmio_print_map(iter); 256 default: 257 return 1; /* ignore unknown entries */ 258 } 259 } 260 261 static struct tracer mmio_tracer __read_mostly = 262 { 263 .name = "mmiotrace", 264 .init = mmio_trace_init, 265 .reset = mmio_trace_reset, 266 .pipe_open = mmio_pipe_open, 267 .close = mmio_close, 268 .read = mmio_read, 269 .ctrl_update = mmio_trace_ctrl_update, 270 .print_line = mmio_print_line, 271 }; 272 273 __init static int init_mmio_trace(void) 274 { 275 return register_tracer(&mmio_tracer); 276 } 277 device_initcall(init_mmio_trace); 278 279 void mmio_trace_rw(struct mmiotrace_rw *rw) 280 { 281 struct trace_array *tr = mmio_trace_array; 282 struct trace_array_cpu *data = tr->data[smp_processor_id()]; 283 __trace_mmiotrace_rw(tr, data, rw); 284 } 285 286 void mmio_trace_mapping(struct mmiotrace_map *map) 287 { 288 struct trace_array *tr = mmio_trace_array; 289 struct trace_array_cpu *data; 290 291 preempt_disable(); 292 data = tr->data[smp_processor_id()]; 293 __trace_mmiotrace_map(tr, data, map); 294 preempt_enable(); 295 } 296