kernel/drivers/hwtracing/coresight/coresight.c

   1 /* Copyright (c) 2012, The Linux Foundation. All rights reserved.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License version 2 and
   5  * only version 2 as published by the Free Software Foundation.
   6  *
   7  * This program is distributed in the hope that it will be useful,
   8  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   9  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10  * GNU General Public License for more details.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/types.h>
  17 #include <linux/device.h>
  18 #include <linux/io.h>
  19 #include <linux/err.h>
  20 #include <linux/export.h>
  21 #include <linux/slab.h>
  22 #include <linux/mutex.h>
  23 #include <linux/clk.h>
  24 #include <linux/coresight.h>
  25 #include <linux/of_platform.h>
  26 #include <linux/delay.h>
  27
  28 #include "coresight-priv.h"
  29
  30 static DEFINE_MUTEX(coresight_mutex);
  31
  32 static int coresight_id_match(struct device *dev, void *data)
  33 {
  34         int trace_id, i_trace_id;
  35         struct coresight_device *csdev, *i_csdev;
  36
  37         csdev = data;
  38         i_csdev = to_coresight_device(dev);
  39
  40         /*
  41          * No need to care about oneself and components that are not
  42          * sources or not enabled
  43          */
  44         if (i_csdev == csdev || !i_csdev->enable ||
  45             i_csdev->type != CORESIGHT_DEV_TYPE_SOURCE)
  46                 return 0;
  47
  48         /* Get the source ID for both compoment */
  49         trace_id = source_ops(csdev)->trace_id(csdev);
  50         i_trace_id = source_ops(i_csdev)->trace_id(i_csdev);
  51
  52         /* All you need is one */
  53         if (trace_id == i_trace_id)
  54                 return 1;
  55
  56         return 0;
  57 }
  58
  59 static int coresight_source_is_unique(struct coresight_device *csdev)
  60 {
  61         int trace_id = source_ops(csdev)->trace_id(csdev);
  62
  63         /* this shouldn't happen */
  64         if (trace_id < 0)
  65                 return 0;
  66
  67         return !bus_for_each_dev(&coresight_bustype, NULL,
  68                                  csdev, coresight_id_match);
  69 }
  70
  71 static int coresight_find_link_inport(struct coresight_device *csdev)
  72 {
  73         int i;
  74         struct coresight_device *parent;
  75         struct coresight_connection *conn;
  76
  77         parent = container_of(csdev->path_link.next,
  78                               struct coresight_device, path_link);
  79
  80         for (i = 0; i < parent->nr_outport; i++) {
  81                 conn = &parent->conns[i];
  82                 if (conn->child_dev == csdev)
  83                         return conn->child_port;
  84         }
  85
  86         dev_err(&csdev->dev, "couldn't find inport, parent: %s, child: %s\n",
  87                 dev_name(&parent->dev), dev_name(&csdev->dev));
  88
  89         return 0;
  90 }
  91
  92 static int coresight_find_link_outport(struct coresight_device *csdev)
  93 {
  94         int i;
  95         struct coresight_device *child;
  96         struct coresight_connection *conn;
  97
  98         child = container_of(csdev->path_link.prev,
  99                              struct coresight_device, path_link);
 100
 101         for (i = 0; i < csdev->nr_outport; i++) {
 102                 conn = &csdev->conns[i];
 103                 if (conn->child_dev == child)
 104                         return conn->outport;
 105         }
 106
 107         dev_err(&csdev->dev, "couldn't find outport, parent: %s, child: %s\n",
 108                 dev_name(&csdev->dev), dev_name(&child->dev));
 109
 110         return 0;
 111 }
 112
 113 static int coresight_enable_sink(struct coresight_device *csdev)
 114 {
 115         int ret;
 116
 117         if (!csdev->enable) {
 118                 if (sink_ops(csdev)->enable) {
 119                         ret = sink_ops(csdev)->enable(csdev);
 120                         if (ret)
 121                                 return ret;
 122                 }
 123                 csdev->enable = true;
 124         }
 125
 126         atomic_inc(csdev->refcnt);
 127
 128         return 0;
 129 }
 130
 131 static void coresight_disable_sink(struct coresight_device *csdev)
 132 {
 133         if (atomic_dec_return(csdev->refcnt) == 0) {
 134                 if (sink_ops(csdev)->disable) {
 135                         sink_ops(csdev)->disable(csdev);
 136                         csdev->enable = false;
 137                 }
 138         }
 139 }
 140
 141 static int coresight_enable_link(struct coresight_device *csdev)
 142 {
 143         int ret;
 144         int link_subtype;
 145         int refport, inport, outport;
 146
 147         inport = coresight_find_link_inport(csdev);
 148         outport = coresight_find_link_outport(csdev);
 149         link_subtype = csdev->subtype.link_subtype;
 150
 151         if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
 152                 refport = inport;
 153         else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
 154                 refport = outport;
 155         else
 156                 refport = 0;
 157
 158         if (atomic_inc_return(&csdev->refcnt[refport]) == 1) {
 159                 if (link_ops(csdev)->enable) {
 160                         ret = link_ops(csdev)->enable(csdev, inport, outport);
 161                         if (ret)
 162                                 return ret;
 163                 }
 164         }
 165
 166         csdev->enable = true;
 167
 168         return 0;
 169 }
 170
 171 static void coresight_disable_link(struct coresight_device *csdev)
 172 {
 173         int i, nr_conns;
 174         int link_subtype;
 175         int refport, inport, outport;
 176
 177         inport = coresight_find_link_inport(csdev);
 178         outport = coresight_find_link_outport(csdev);
 179         link_subtype = csdev->subtype.link_subtype;
 180
 181         if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG) {
 182                 refport = inport;
 183                 nr_conns = csdev->nr_inport;
 184         } else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT) {
 185                 refport = outport;
 186                 nr_conns = csdev->nr_outport;
 187         } else {
 188                 refport = 0;
 189                 nr_conns = 1;
 190         }
 191
 192         if (atomic_dec_return(&csdev->refcnt[refport]) == 0) {
 193                 if (link_ops(csdev)->disable)
 194                         link_ops(csdev)->disable(csdev, inport, outport);
 195         }
 196
 197         for (i = 0; i < nr_conns; i++)
 198                 if (atomic_read(&csdev->refcnt[i]) != 0)
 199                         return;
 200
 201         csdev->enable = false;
 202 }
 203
 204 static int coresight_enable_source(struct coresight_device *csdev)
 205 {
 206         int ret;
 207
 208         if (!coresight_source_is_unique(csdev)) {
 209                 dev_warn(&csdev->dev, "traceID %d not unique\n",
 210                          source_ops(csdev)->trace_id(csdev));
 211                 return -EINVAL;
 212         }
 213
 214         if (!csdev->enable) {
 215                 if (source_ops(csdev)->enable) {
 216                         ret = source_ops(csdev)->enable(csdev);
 217                         if (ret)
 218                                 return ret;
 219                 }
 220                 csdev->enable = true;
 221         }
 222
 223         atomic_inc(csdev->refcnt);
 224
 225         return 0;
 226 }
 227
 228 static void coresight_disable_source(struct coresight_device *csdev)
 229 {
 230         if (atomic_dec_return(csdev->refcnt) == 0) {
 231                 if (source_ops(csdev)->disable) {
 232                         source_ops(csdev)->disable(csdev);
 233                         csdev->enable = false;
 234                 }
 235         }
 236 }
 237
 238 static int coresight_enable_path(struct list_head *path)
 239 {
 240         int ret = 0;
 241         struct coresight_device *cd;
 242
 243         list_for_each_entry(cd, path, path_link) {
 244                 if (cd == list_first_entry(path, struct coresight_device,
 245                                            path_link)) {
 246                         ret = coresight_enable_sink(cd);
 247                 } else if (list_is_last(&cd->path_link, path)) {
 248                         /*
 249                          * Don't enable the source just yet - this needs to
 250                          * happen at the very end when all links and sink
 251                          * along the path have been configured properly.
 252                          */
 253                         ;
 254                 } else {
 255                         ret = coresight_enable_link(cd);
 256                 }
 257                 if (ret)
 258                         goto err;
 259         }
 260
 261         return 0;
 262 err:
 263         list_for_each_entry_continue_reverse(cd, path, path_link) {
 264                 if (cd == list_first_entry(path, struct coresight_device,
 265                                            path_link)) {
 266                         coresight_disable_sink(cd);
 267                 } else if (list_is_last(&cd->path_link, path)) {
 268                         ;
 269                 } else {
 270                         coresight_disable_link(cd);
 271                 }
 272         }
 273
 274         return ret;
 275 }
 276
 277 static int coresight_disable_path(struct list_head *path)
 278 {
 279         struct coresight_device *cd;
 280
 281         list_for_each_entry_reverse(cd, path, path_link) {
 282                 if (cd == list_first_entry(path, struct coresight_device,
 283                                            path_link)) {
 284                         coresight_disable_sink(cd);
 285                 } else if (list_is_last(&cd->path_link, path)) {
 286                         /*
 287                          * The source has already been stopped, no need
 288                          * to do it again here.
 289                          */
 290                         ;
 291                 } else {
 292                         coresight_disable_link(cd);
 293                 }
 294         }
 295
 296         return 0;
 297 }
 298
 299 static int coresight_build_paths(struct coresight_device *csdev,
 300                                  struct list_head *path,
 301                                  bool enable)
 302 {
 303         int i, ret = -EINVAL;
 304         struct coresight_connection *conn;
 305
 306         list_add(&csdev->path_link, path);
 307
 308         if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
 309             csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
 310             csdev->activated) {
 311                 if (enable)
 312                         ret = coresight_enable_path(path);
 313                 else
 314                         ret = coresight_disable_path(path);
 315         } else {
 316                 for (i = 0; i < csdev->nr_outport; i++) {
 317                         conn = &csdev->conns[i];
 318                         if (coresight_build_paths(conn->child_dev,
 319                                                     path, enable) == 0)
 320                                 ret = 0;
 321                 }
 322         }
 323
 324         if (list_first_entry(path, struct coresight_device, path_link) != csdev)
 325                 dev_err(&csdev->dev, "wrong device in %s\n", __func__);
 326
 327         list_del(&csdev->path_link);
 328
 329         return ret;
 330 }
 331
 332 int coresight_enable(struct coresight_device *csdev)
 333 {
 334         int ret = 0;
 335         LIST_HEAD(path);
 336
 337         mutex_lock(&coresight_mutex);
 338         if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
 339                 ret = -EINVAL;
 340                 dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
 341                 goto out;
 342         }
 343         if (csdev->enable)
 344                 goto out;
 345
 346         if (coresight_build_paths(csdev, &path, true)) {
 347                 dev_err(&csdev->dev, "building path(s) failed\n");
 348                 goto out;
 349         }
 350
 351         if (coresight_enable_source(csdev))
 352                 dev_err(&csdev->dev, "source enable failed\n");
 353 out:
 354         mutex_unlock(&coresight_mutex);
 355         return ret;
 356 }
 357 EXPORT_SYMBOL_GPL(coresight_enable);
 358
 359 void coresight_disable(struct coresight_device *csdev)
 360 {
 361         LIST_HEAD(path);
 362
 363         mutex_lock(&coresight_mutex);
 364         if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
 365                 dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
 366                 goto out;
 367         }
 368         if (!csdev->enable)
 369                 goto out;
 370
 371         coresight_disable_source(csdev);
 372         if (coresight_build_paths(csdev, &path, false))
 373                 dev_err(&csdev->dev, "releasing path(s) failed\n");
 374
 375 out:
 376         mutex_unlock(&coresight_mutex);
 377 }
 378 EXPORT_SYMBOL_GPL(coresight_disable);
 379
 380 static ssize_t enable_sink_show(struct device *dev,
 381                                 struct device_attribute *attr, char *buf)
 382 {
 383         struct coresight_device *csdev = to_coresight_device(dev);
 384
 385         return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->activated);
 386 }
 387
 388 static ssize_t enable_sink_store(struct device *dev,
 389                                  struct device_attribute *attr,
 390                                  const char *buf, size_t size)
 391 {
 392         int ret;
 393         unsigned long val;
 394         struct coresight_device *csdev = to_coresight_device(dev);
 395
 396         ret = kstrtoul(buf, 10, &val);
 397         if (ret)
 398                 return ret;
 399
 400         if (val)
 401                 csdev->activated = true;
 402         else
 403                 csdev->activated = false;
 404
 405         return size;
 406
 407 }
 408 static DEVICE_ATTR_RW(enable_sink);
 409
 410 static ssize_t enable_source_show(struct device *dev,
 411                                   struct device_attribute *attr, char *buf)
 412 {
 413         struct coresight_device *csdev = to_coresight_device(dev);
 414
 415         return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->enable);
 416 }
 417
 418 static ssize_t enable_source_store(struct device *dev,
 419                                    struct device_attribute *attr,
 420                                    const char *buf, size_t size)
 421 {
 422         int ret = 0;
 423         unsigned long val;
 424         struct coresight_device *csdev = to_coresight_device(dev);
 425
 426         ret = kstrtoul(buf, 10, &val);
 427         if (ret)
 428                 return ret;
 429
 430         if (val) {
 431                 ret = coresight_enable(csdev);
 432                 if (ret)
 433                         return ret;
 434         } else {
 435                 coresight_disable(csdev);
 436         }
 437
 438         return size;
 439 }
 440 static DEVICE_ATTR_RW(enable_source);
 441
 442 static struct attribute *coresight_sink_attrs[] = {
 443         &dev_attr_enable_sink.attr,
 444         NULL,
 445 };
 446 ATTRIBUTE_GROUPS(coresight_sink);
 447
 448 static struct attribute *coresight_source_attrs[] = {
 449         &dev_attr_enable_source.attr,
 450         NULL,
 451 };
 452 ATTRIBUTE_GROUPS(coresight_source);
 453
 454 static struct device_type coresight_dev_type[] = {
 455         {
 456                 .name = "none",
 457         },
 458         {
 459                 .name = "sink",
 460                 .groups = coresight_sink_groups,
 461         },
 462         {
 463                 .name = "link",
 464         },
 465         {
 466                 .name = "linksink",
 467                 .groups = coresight_sink_groups,
 468         },
 469         {
 470                 .name = "source",
 471                 .groups = coresight_source_groups,
 472         },
 473 };
 474
 475 static void coresight_device_release(struct device *dev)
 476 {
 477         struct coresight_device *csdev = to_coresight_device(dev);
 478
 479         kfree(csdev);
 480 }
 481
 482 static int coresight_orphan_match(struct device *dev, void *data)
 483 {
 484         int i;
 485         bool still_orphan = false;
 486         struct coresight_device *csdev, *i_csdev;
 487         struct coresight_connection *conn;
 488
 489         csdev = data;
 490         i_csdev = to_coresight_device(dev);
 491
 492         /* No need to check oneself */
 493         if (csdev == i_csdev)
 494                 return 0;
 495
 496         /* Move on to another component if no connection is orphan */
 497         if (!i_csdev->orphan)
 498                 return 0;
 499         /*
 500          * Circle throuch all the connection of that component.  If we find
 501          * an orphan connection whose name matches @csdev, link it.
 502          */
 503         for (i = 0; i < i_csdev->nr_outport; i++) {
 504                 conn = &i_csdev->conns[i];
 505
 506                 /* We have found at least one orphan connection */
 507                 if (conn->child_dev == NULL) {
 508                         /* Does it match this newly added device? */
 509                         if (!strcmp(dev_name(&csdev->dev), conn->child_name)) {
 510                                 conn->child_dev = csdev;
 511                         } else {
 512                                 /* This component still has an orphan */
 513                                 still_orphan = true;
 514                         }
 515                 }
 516         }
 517
 518         i_csdev->orphan = still_orphan;
 519
 520         /*
 521          * Returning '0' ensures that all known component on the
 522          * bus will be checked.
 523          */
 524         return 0;
 525 }
 526
 527 static void coresight_fixup_orphan_conns(struct coresight_device *csdev)
 528 {
 529         /*
 530          * No need to check for a return value as orphan connection(s)
 531          * are hooked-up with each newly added component.
 532          */
 533         bus_for_each_dev(&coresight_bustype, NULL,
 534                                  csdev, coresight_orphan_match);
 535 }
 536
 537
 538 static int coresight_name_match(struct device *dev, void *data)
 539 {
 540         char *to_match;
 541         struct coresight_device *i_csdev;
 542
 543         to_match = data;
 544         i_csdev = to_coresight_device(dev);
 545
 546         if (!strcmp(to_match, dev_name(&i_csdev->dev)))
 547                 return 1;
 548
 549         return 0;
 550 }
 551
 552 static void coresight_fixup_device_conns(struct coresight_device *csdev)
 553 {
 554         int i;
 555         struct device *dev = NULL;
 556         struct coresight_connection *conn;
 557
 558         for (i = 0; i < csdev->nr_outport; i++) {
 559                 conn = &csdev->conns[i];
 560                 dev = bus_find_device(&coresight_bustype, NULL,
 561                                       (void *)conn->child_name,
 562                                       coresight_name_match);
 563
 564                 if (dev) {
 565                         conn->child_dev = to_coresight_device(dev);
 566                 } else {
 567                         csdev->orphan = true;
 568                         conn->child_dev = NULL;
 569                 }
 570         }
 571 }
 572
 573 /**
 574  * coresight_timeout - loop until a bit has changed to a specific state.
 575  * @addr: base address of the area of interest.
 576  * @offset: address of a register, starting from @addr.
 577  * @position: the position of the bit of interest.
 578  * @value: the value the bit should have.
 579  *
 580  * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
 581  * TIMEOUT_US has elapsed, which ever happens first.
 582  */
 583
 584 int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
 585 {
 586         int i;
 587         u32 val;
 588
 589         for (i = TIMEOUT_US; i > 0; i--) {
 590                 val = __raw_readl(addr + offset);
 591                 /* waiting on the bit to go from 0 to 1 */
 592                 if (value) {
 593                         if (val & BIT(position))
 594                                 return 0;
 595                 /* waiting on the bit to go from 1 to 0 */
 596                 } else {
 597                         if (!(val & BIT(position)))
 598                                 return 0;
 599                 }
 600
 601                 /*
 602                  * Delay is arbitrary - the specification doesn't say how long
 603                  * we are expected to wait.  Extra check required to make sure
 604                  * we don't wait needlessly on the last iteration.
 605                  */
 606                 if (i - 1)
 607                         udelay(1);
 608         }
 609
 610         return -EAGAIN;
 611 }
 612
 613 struct bus_type coresight_bustype = {
 614         .name   = "coresight",
 615 };
 616
 617 static int __init coresight_init(void)
 618 {
 619         return bus_register(&coresight_bustype);
 620 }
 621 postcore_initcall(coresight_init);
 622
 623 struct coresight_device *coresight_register(struct coresight_desc *desc)
 624 {
 625         int i;
 626         int ret;
 627         int link_subtype;
 628         int nr_refcnts = 1;
 629         atomic_t *refcnts = NULL;
 630         struct coresight_device *csdev;
 631         struct coresight_connection *conns;
 632
 633         csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
 634         if (!csdev) {
 635                 ret = -ENOMEM;
 636                 goto err_kzalloc_csdev;
 637         }
 638
 639         if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
 640             desc->type == CORESIGHT_DEV_TYPE_LINKSINK) {
 641                 link_subtype = desc->subtype.link_subtype;
 642
 643                 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
 644                         nr_refcnts = desc->pdata->nr_inport;
 645                 else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
 646                         nr_refcnts = desc->pdata->nr_outport;
 647         }
 648
 649         refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
 650         if (!refcnts) {
 651                 ret = -ENOMEM;
 652                 goto err_kzalloc_refcnts;
 653         }
 654
 655         csdev->refcnt = refcnts;
 656
 657         csdev->nr_inport = desc->pdata->nr_inport;
 658         csdev->nr_outport = desc->pdata->nr_outport;
 659         conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
 660         if (!conns) {
 661                 ret = -ENOMEM;
 662                 goto err_kzalloc_conns;
 663         }
 664
 665         for (i = 0; i < csdev->nr_outport; i++) {
 666                 conns[i].outport = desc->pdata->outports[i];
 667                 conns[i].child_name = desc->pdata->child_names[i];
 668                 conns[i].child_port = desc->pdata->child_ports[i];
 669         }
 670
 671         csdev->conns = conns;
 672
 673         csdev->type = desc->type;
 674         csdev->subtype = desc->subtype;
 675         csdev->ops = desc->ops;
 676         csdev->orphan = false;
 677
 678         csdev->dev.type = &coresight_dev_type[desc->type];
 679         csdev->dev.groups = desc->groups;
 680         csdev->dev.parent = desc->dev;
 681         csdev->dev.release = coresight_device_release;
 682         csdev->dev.bus = &coresight_bustype;
 683         dev_set_name(&csdev->dev, "%s", desc->pdata->name);
 684
 685         ret = device_register(&csdev->dev);
 686         if (ret)
 687                 goto err_device_register;
 688
 689         mutex_lock(&coresight_mutex);
 690
 691         coresight_fixup_device_conns(csdev);
 692         coresight_fixup_orphan_conns(csdev);
 693
 694         mutex_unlock(&coresight_mutex);
 695
 696         return csdev;
 697
 698 err_device_register:
 699         kfree(conns);
 700 err_kzalloc_conns:
 701         kfree(refcnts);
 702 err_kzalloc_refcnts:
 703         kfree(csdev);
 704 err_kzalloc_csdev:
 705         return ERR_PTR(ret);
 706 }
 707 EXPORT_SYMBOL_GPL(coresight_register);
 708
 709 void coresight_unregister(struct coresight_device *csdev)
 710 {
 711         mutex_lock(&coresight_mutex);
 712
 713         kfree(csdev->conns);
 714         device_unregister(&csdev->dev);
 715
 716         mutex_unlock(&coresight_mutex);
 717 }
 718 EXPORT_SYMBOL_GPL(coresight_unregister);
 719
 720 MODULE_LICENSE("GPL v2");