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         /*
 244          * At this point we have a full @path, from source to sink.  The
 245          * sink is the first entry and the source the last one.  Go through
 246          * all the components and enable them one by one.
 247          */
 248         list_for_each_entry(cd, path, path_link) {
 249                 if (cd == list_first_entry(path, struct coresight_device,
 250                                            path_link)) {
 251                         ret = coresight_enable_sink(cd);
 252                 } else if (list_is_last(&cd->path_link, path)) {
 253                         /*
 254                          * Don't enable the source just yet - this needs to
 255                          * happen at the very end when all links and sink
 256                          * along the path have been configured properly.
 257                          */
 258                         ;
 259                 } else {
 260                         ret = coresight_enable_link(cd);
 261                 }
 262                 if (ret)
 263                         goto err;
 264         }
 265
 266         return 0;
 267 err:
 268         list_for_each_entry_continue_reverse(cd, path, path_link) {
 269                 if (cd == list_first_entry(path, struct coresight_device,
 270                                            path_link)) {
 271                         coresight_disable_sink(cd);
 272                 } else if (list_is_last(&cd->path_link, path)) {
 273                         ;
 274                 } else {
 275                         coresight_disable_link(cd);
 276                 }
 277         }
 278
 279         return ret;
 280 }
 281
 282 static int coresight_disable_path(struct list_head *path)
 283 {
 284         struct coresight_device *cd;
 285
 286         list_for_each_entry_reverse(cd, path, path_link) {
 287                 if (cd == list_first_entry(path, struct coresight_device,
 288                                            path_link)) {
 289                         coresight_disable_sink(cd);
 290                 } else if (list_is_last(&cd->path_link, path)) {
 291                         /*
 292                          * The source has already been stopped, no need
 293                          * to do it again here.
 294                          */
 295                         ;
 296                 } else {
 297                         coresight_disable_link(cd);
 298                 }
 299         }
 300
 301         return 0;
 302 }
 303
 304 static int coresight_build_paths(struct coresight_device *csdev,
 305                                  struct list_head *path,
 306                                  bool enable)
 307 {
 308         int i, ret = -EINVAL;
 309         struct coresight_connection *conn;
 310
 311         list_add(&csdev->path_link, path);
 312
 313         if ((csdev->type == CORESIGHT_DEV_TYPE_SINK ||
 314             csdev->type == CORESIGHT_DEV_TYPE_LINKSINK) &&
 315             csdev->activated) {
 316                 if (enable)
 317                         ret = coresight_enable_path(path);
 318                 else
 319                         ret = coresight_disable_path(path);
 320         } else {
 321                 for (i = 0; i < csdev->nr_outport; i++) {
 322                         conn = &csdev->conns[i];
 323                         if (coresight_build_paths(conn->child_dev,
 324                                                     path, enable) == 0)
 325                                 ret = 0;
 326                 }
 327         }
 328
 329         if (list_first_entry(path, struct coresight_device, path_link) != csdev)
 330                 dev_err(&csdev->dev, "wrong device in %s\n", __func__);
 331
 332         list_del(&csdev->path_link);
 333
 334         return ret;
 335 }
 336
 337 int coresight_enable(struct coresight_device *csdev)
 338 {
 339         int ret = 0;
 340         LIST_HEAD(path);
 341
 342         mutex_lock(&coresight_mutex);
 343         if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
 344                 ret = -EINVAL;
 345                 dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
 346                 goto out;
 347         }
 348         if (csdev->enable)
 349                 goto out;
 350
 351         if (coresight_build_paths(csdev, &path, true)) {
 352                 dev_err(&csdev->dev, "building path(s) failed\n");
 353                 goto out;
 354         }
 355
 356         if (coresight_enable_source(csdev))
 357                 dev_err(&csdev->dev, "source enable failed\n");
 358 out:
 359         mutex_unlock(&coresight_mutex);
 360         return ret;
 361 }
 362 EXPORT_SYMBOL_GPL(coresight_enable);
 363
 364 void coresight_disable(struct coresight_device *csdev)
 365 {
 366         LIST_HEAD(path);
 367
 368         mutex_lock(&coresight_mutex);
 369         if (csdev->type != CORESIGHT_DEV_TYPE_SOURCE) {
 370                 dev_err(&csdev->dev, "wrong device type in %s\n", __func__);
 371                 goto out;
 372         }
 373         if (!csdev->enable)
 374                 goto out;
 375
 376         coresight_disable_source(csdev);
 377         if (coresight_build_paths(csdev, &path, false))
 378                 dev_err(&csdev->dev, "releasing path(s) failed\n");
 379
 380 out:
 381         mutex_unlock(&coresight_mutex);
 382 }
 383 EXPORT_SYMBOL_GPL(coresight_disable);
 384
 385 static ssize_t enable_sink_show(struct device *dev,
 386                                 struct device_attribute *attr, char *buf)
 387 {
 388         struct coresight_device *csdev = to_coresight_device(dev);
 389
 390         return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->activated);
 391 }
 392
 393 static ssize_t enable_sink_store(struct device *dev,
 394                                  struct device_attribute *attr,
 395                                  const char *buf, size_t size)
 396 {
 397         int ret;
 398         unsigned long val;
 399         struct coresight_device *csdev = to_coresight_device(dev);
 400
 401         ret = kstrtoul(buf, 10, &val);
 402         if (ret)
 403                 return ret;
 404
 405         if (val)
 406                 csdev->activated = true;
 407         else
 408                 csdev->activated = false;
 409
 410         return size;
 411
 412 }
 413 static DEVICE_ATTR_RW(enable_sink);
 414
 415 static ssize_t enable_source_show(struct device *dev,
 416                                   struct device_attribute *attr, char *buf)
 417 {
 418         struct coresight_device *csdev = to_coresight_device(dev);
 419
 420         return scnprintf(buf, PAGE_SIZE, "%u\n", (unsigned)csdev->enable);
 421 }
 422
 423 static ssize_t enable_source_store(struct device *dev,
 424                                    struct device_attribute *attr,
 425                                    const char *buf, size_t size)
 426 {
 427         int ret = 0;
 428         unsigned long val;
 429         struct coresight_device *csdev = to_coresight_device(dev);
 430
 431         ret = kstrtoul(buf, 10, &val);
 432         if (ret)
 433                 return ret;
 434
 435         if (val) {
 436                 ret = coresight_enable(csdev);
 437                 if (ret)
 438                         return ret;
 439         } else {
 440                 coresight_disable(csdev);
 441         }
 442
 443         return size;
 444 }
 445 static DEVICE_ATTR_RW(enable_source);
 446
 447 static struct attribute *coresight_sink_attrs[] = {
 448         &dev_attr_enable_sink.attr,
 449         NULL,
 450 };
 451 ATTRIBUTE_GROUPS(coresight_sink);
 452
 453 static struct attribute *coresight_source_attrs[] = {
 454         &dev_attr_enable_source.attr,
 455         NULL,
 456 };
 457 ATTRIBUTE_GROUPS(coresight_source);
 458
 459 static struct device_type coresight_dev_type[] = {
 460         {
 461                 .name = "none",
 462         },
 463         {
 464                 .name = "sink",
 465                 .groups = coresight_sink_groups,
 466         },
 467         {
 468                 .name = "link",
 469         },
 470         {
 471                 .name = "linksink",
 472                 .groups = coresight_sink_groups,
 473         },
 474         {
 475                 .name = "source",
 476                 .groups = coresight_source_groups,
 477         },
 478 };
 479
 480 static void coresight_device_release(struct device *dev)
 481 {
 482         struct coresight_device *csdev = to_coresight_device(dev);
 483
 484         kfree(csdev);
 485 }
 486
 487 static int coresight_orphan_match(struct device *dev, void *data)
 488 {
 489         int i;
 490         bool still_orphan = false;
 491         struct coresight_device *csdev, *i_csdev;
 492         struct coresight_connection *conn;
 493
 494         csdev = data;
 495         i_csdev = to_coresight_device(dev);
 496
 497         /* No need to check oneself */
 498         if (csdev == i_csdev)
 499                 return 0;
 500
 501         /* Move on to another component if no connection is orphan */
 502         if (!i_csdev->orphan)
 503                 return 0;
 504         /*
 505          * Circle throuch all the connection of that component.  If we find
 506          * an orphan connection whose name matches @csdev, link it.
 507          */
 508         for (i = 0; i < i_csdev->nr_outport; i++) {
 509                 conn = &i_csdev->conns[i];
 510
 511                 /* We have found at least one orphan connection */
 512                 if (conn->child_dev == NULL) {
 513                         /* Does it match this newly added device? */
 514                         if (!strcmp(dev_name(&csdev->dev), conn->child_name)) {
 515                                 conn->child_dev = csdev;
 516                         } else {
 517                                 /* This component still has an orphan */
 518                                 still_orphan = true;
 519                         }
 520                 }
 521         }
 522
 523         i_csdev->orphan = still_orphan;
 524
 525         /*
 526          * Returning '0' ensures that all known component on the
 527          * bus will be checked.
 528          */
 529         return 0;
 530 }
 531
 532 static void coresight_fixup_orphan_conns(struct coresight_device *csdev)
 533 {
 534         /*
 535          * No need to check for a return value as orphan connection(s)
 536          * are hooked-up with each newly added component.
 537          */
 538         bus_for_each_dev(&coresight_bustype, NULL,
 539                                  csdev, coresight_orphan_match);
 540 }
 541
 542
 543 static int coresight_name_match(struct device *dev, void *data)
 544 {
 545         char *to_match;
 546         struct coresight_device *i_csdev;
 547
 548         to_match = data;
 549         i_csdev = to_coresight_device(dev);
 550
 551         if (to_match && !strcmp(to_match, dev_name(&i_csdev->dev)))
 552                 return 1;
 553
 554         return 0;
 555 }
 556
 557 static void coresight_fixup_device_conns(struct coresight_device *csdev)
 558 {
 559         int i;
 560         struct device *dev = NULL;
 561         struct coresight_connection *conn;
 562
 563         for (i = 0; i < csdev->nr_outport; i++) {
 564                 conn = &csdev->conns[i];
 565                 dev = bus_find_device(&coresight_bustype, NULL,
 566                                       (void *)conn->child_name,
 567                                       coresight_name_match);
 568
 569                 if (dev) {
 570                         conn->child_dev = to_coresight_device(dev);
 571                 } else {
 572                         csdev->orphan = true;
 573                         conn->child_dev = NULL;
 574                 }
 575         }
 576 }
 577
 578 /**
 579  * coresight_timeout - loop until a bit has changed to a specific state.
 580  * @addr: base address of the area of interest.
 581  * @offset: address of a register, starting from @addr.
 582  * @position: the position of the bit of interest.
 583  * @value: the value the bit should have.
 584  *
 585  * Return: 0 as soon as the bit has taken the desired state or -EAGAIN if
 586  * TIMEOUT_US has elapsed, which ever happens first.
 587  */
 588
 589 int coresight_timeout(void __iomem *addr, u32 offset, int position, int value)
 590 {
 591         int i;
 592         u32 val;
 593
 594         for (i = TIMEOUT_US; i > 0; i--) {
 595                 val = __raw_readl(addr + offset);
 596                 /* waiting on the bit to go from 0 to 1 */
 597                 if (value) {
 598                         if (val & BIT(position))
 599                                 return 0;
 600                 /* waiting on the bit to go from 1 to 0 */
 601                 } else {
 602                         if (!(val & BIT(position)))
 603                                 return 0;
 604                 }
 605
 606                 /*
 607                  * Delay is arbitrary - the specification doesn't say how long
 608                  * we are expected to wait.  Extra check required to make sure
 609                  * we don't wait needlessly on the last iteration.
 610                  */
 611                 if (i - 1)
 612                         udelay(1);
 613         }
 614
 615         return -EAGAIN;
 616 }
 617
 618 struct bus_type coresight_bustype = {
 619         .name   = "coresight",
 620 };
 621
 622 static int __init coresight_init(void)
 623 {
 624         return bus_register(&coresight_bustype);
 625 }
 626 postcore_initcall(coresight_init);
 627
 628 struct coresight_device *coresight_register(struct coresight_desc *desc)
 629 {
 630         int i;
 631         int ret;
 632         int link_subtype;
 633         int nr_refcnts = 1;
 634         atomic_t *refcnts = NULL;
 635         struct coresight_device *csdev;
 636         struct coresight_connection *conns;
 637
 638         csdev = kzalloc(sizeof(*csdev), GFP_KERNEL);
 639         if (!csdev) {
 640                 ret = -ENOMEM;
 641                 goto err_kzalloc_csdev;
 642         }
 643
 644         if (desc->type == CORESIGHT_DEV_TYPE_LINK ||
 645             desc->type == CORESIGHT_DEV_TYPE_LINKSINK) {
 646                 link_subtype = desc->subtype.link_subtype;
 647
 648                 if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_MERG)
 649                         nr_refcnts = desc->pdata->nr_inport;
 650                 else if (link_subtype == CORESIGHT_DEV_SUBTYPE_LINK_SPLIT)
 651                         nr_refcnts = desc->pdata->nr_outport;
 652         }
 653
 654         refcnts = kcalloc(nr_refcnts, sizeof(*refcnts), GFP_KERNEL);
 655         if (!refcnts) {
 656                 ret = -ENOMEM;
 657                 goto err_kzalloc_refcnts;
 658         }
 659
 660         csdev->refcnt = refcnts;
 661
 662         csdev->nr_inport = desc->pdata->nr_inport;
 663         csdev->nr_outport = desc->pdata->nr_outport;
 664         conns = kcalloc(csdev->nr_outport, sizeof(*conns), GFP_KERNEL);
 665         if (!conns) {
 666                 ret = -ENOMEM;
 667                 goto err_kzalloc_conns;
 668         }
 669
 670         for (i = 0; i < csdev->nr_outport; i++) {
 671                 conns[i].outport = desc->pdata->outports[i];
 672                 conns[i].child_name = desc->pdata->child_names[i];
 673                 conns[i].child_port = desc->pdata->child_ports[i];
 674         }
 675
 676         csdev->conns = conns;
 677
 678         csdev->type = desc->type;
 679         csdev->subtype = desc->subtype;
 680         csdev->ops = desc->ops;
 681         csdev->orphan = false;
 682
 683         csdev->dev.type = &coresight_dev_type[desc->type];
 684         csdev->dev.groups = desc->groups;
 685         csdev->dev.parent = desc->dev;
 686         csdev->dev.release = coresight_device_release;
 687         csdev->dev.bus = &coresight_bustype;
 688         dev_set_name(&csdev->dev, "%s", desc->pdata->name);
 689
 690         ret = device_register(&csdev->dev);
 691         if (ret)
 692                 goto err_device_register;
 693
 694         mutex_lock(&coresight_mutex);
 695
 696         coresight_fixup_device_conns(csdev);
 697         coresight_fixup_orphan_conns(csdev);
 698
 699         mutex_unlock(&coresight_mutex);
 700
 701         return csdev;
 702
 703 err_device_register:
 704         kfree(conns);
 705 err_kzalloc_conns:
 706         kfree(refcnts);
 707 err_kzalloc_refcnts:
 708         kfree(csdev);
 709 err_kzalloc_csdev:
 710         return ERR_PTR(ret);
 711 }
 712 EXPORT_SYMBOL_GPL(coresight_register);
 713
 714 void coresight_unregister(struct coresight_device *csdev)
 715 {
 716         mutex_lock(&coresight_mutex);
 717
 718         kfree(csdev->conns);
 719         device_unregister(&csdev->dev);
 720
 721         mutex_unlock(&coresight_mutex);
 722 }
 723 EXPORT_SYMBOL_GPL(coresight_unregister);
 724
 725 MODULE_LICENSE("GPL v2");