drivers/base/devres.c

   1 /*
   2  * drivers/base/devres.c - device resource management
   3  *
   4  * Copyright (c) 2006  SUSE Linux Products GmbH
   5  * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
   6  *
   7  * This file is released under the GPLv2.
   8  */
   9
  10 #include <linux/device.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13
  14 #include "base.h"
  15
  16 struct devres_node {
  17         struct list_head                entry;
  18         dr_release_t                    release;
  19 #ifdef CONFIG_DEBUG_DEVRES
  20         const char                      *name;
  21         size_t                          size;
  22 #endif
  23 };
  24
  25 struct devres {
  26         struct devres_node              node;
  27         /* -- 3 pointers */
  28         unsigned long long              data[]; /* guarantee ull alignment */
  29 };
  30
  31 struct devres_group {
  32         struct devres_node              node[2];
  33         void                            *id;
  34         int                             color;
  35         /* -- 8 pointers */
  36 };
  37
  38 #ifdef CONFIG_DEBUG_DEVRES
  39 static int log_devres = 0;
  40 module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
  41
  42 static void set_node_dbginfo(struct devres_node *node, const char *name,
  43                              size_t size)
  44 {
  45         node->name = name;
  46         node->size = size;
  47 }
  48
  49 static void devres_log(struct device *dev, struct devres_node *node,
  50                        const char *op)
  51 {
  52         if (unlikely(log_devres))
  53                 dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
  54                         op, node, node->name, (unsigned long)node->size);
  55 }
  56 #else /* CONFIG_DEBUG_DEVRES */
  57 #define set_node_dbginfo(node, n, s)    do {} while (0)
  58 #define devres_log(dev, node, op)       do {} while (0)
  59 #endif /* CONFIG_DEBUG_DEVRES */
  60
  61 /*
  62  * Release functions for devres group.  These callbacks are used only
  63  * for identification.
  64  */
  65 static void group_open_release(struct device *dev, void *res)
  66 {
  67         /* noop */
  68 }
  69
  70 static void group_close_release(struct device *dev, void *res)
  71 {
  72         /* noop */
  73 }
  74
  75 static struct devres_group * node_to_group(struct devres_node *node)
  76 {
  77         if (node->release == &group_open_release)
  78                 return container_of(node, struct devres_group, node[0]);
  79         if (node->release == &group_close_release)
  80                 return container_of(node, struct devres_group, node[1]);
  81         return NULL;
  82 }
  83
  84 static __always_inline struct devres * alloc_dr(dr_release_t release,
  85                                                 size_t size, gfp_t gfp, int nid)
  86 {
  87         size_t tot_size = sizeof(struct devres) + size;
  88         struct devres *dr;
  89
  90         dr = kmalloc_node_track_caller(tot_size, gfp, nid);
  91         if (unlikely(!dr))
  92                 return NULL;
  93
  94         memset(dr, 0, offsetof(struct devres, data));
  95
  96         INIT_LIST_HEAD(&dr->node.entry);
  97         dr->node.release = release;
  98         return dr;
  99 }
 100
 101 static void add_dr(struct device *dev, struct devres_node *node)
 102 {
 103         devres_log(dev, node, "ADD");
 104         BUG_ON(!list_empty(&node->entry));
 105         list_add_tail(&node->entry, &dev->devres_head);
 106 }
 107
 108 #ifdef CONFIG_DEBUG_DEVRES
 109 void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
 110                       const char *name)
 111 {
 112         struct devres *dr;
 113
 114         dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
 115         if (unlikely(!dr))
 116                 return NULL;
 117         set_node_dbginfo(&dr->node, name, size);
 118         return dr->data;
 119 }
 120 EXPORT_SYMBOL_GPL(__devres_alloc_node);
 121 #else
 122 /**
 123  * devres_alloc - Allocate device resource data
 124  * @release: Release function devres will be associated with
 125  * @size: Allocation size
 126  * @gfp: Allocation flags
 127  * @nid: NUMA node
 128  *
 129  * Allocate devres of @size bytes.  The allocated area is zeroed, then
 130  * associated with @release.  The returned pointer can be passed to
 131  * other devres_*() functions.
 132  *
 133  * RETURNS:
 134  * Pointer to allocated devres on success, NULL on failure.
 135  */
 136 void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
 137 {
 138         struct devres *dr;
 139
 140         dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
 141         if (unlikely(!dr))
 142                 return NULL;
 143         return dr->data;
 144 }
 145 EXPORT_SYMBOL_GPL(devres_alloc_node);
 146 #endif
 147
 148 /**
 149  * devres_for_each_res - Resource iterator
 150  * @dev: Device to iterate resource from
 151  * @release: Look for resources associated with this release function
 152  * @match: Match function (optional)
 153  * @match_data: Data for the match function
 154  * @fn: Function to be called for each matched resource.
 155  * @data: Data for @fn, the 3rd parameter of @fn
 156  *
 157  * Call @fn for each devres of @dev which is associated with @release
 158  * and for which @match returns 1.
 159  *
 160  * RETURNS:
 161  *      void
 162  */
 163 void devres_for_each_res(struct device *dev, dr_release_t release,
 164                         dr_match_t match, void *match_data,
 165                         void (*fn)(struct device *, void *, void *),
 166                         void *data)
 167 {
 168         struct devres_node *node;
 169         struct devres_node *tmp;
 170         unsigned long flags;
 171
 172         if (!fn)
 173                 return;
 174
 175         spin_lock_irqsave(&dev->devres_lock, flags);
 176         list_for_each_entry_safe_reverse(node, tmp,
 177                         &dev->devres_head, entry) {
 178                 struct devres *dr = container_of(node, struct devres, node);
 179
 180                 if (node->release != release)
 181                         continue;
 182                 if (match && !match(dev, dr->data, match_data))
 183                         continue;
 184                 fn(dev, dr->data, data);
 185         }
 186         spin_unlock_irqrestore(&dev->devres_lock, flags);
 187 }
 188 EXPORT_SYMBOL_GPL(devres_for_each_res);
 189
 190 /**
 191  * devres_free - Free device resource data
 192  * @res: Pointer to devres data to free
 193  *
 194  * Free devres created with devres_alloc().
 195  */
 196 void devres_free(void *res)
 197 {
 198         if (res) {
 199                 struct devres *dr = container_of(res, struct devres, data);
 200
 201                 BUG_ON(!list_empty(&dr->node.entry));
 202                 kfree(dr);
 203         }
 204 }
 205 EXPORT_SYMBOL_GPL(devres_free);
 206
 207 /**
 208  * devres_add - Register device resource
 209  * @dev: Device to add resource to
 210  * @res: Resource to register
 211  *
 212  * Register devres @res to @dev.  @res should have been allocated
 213  * using devres_alloc().  On driver detach, the associated release
 214  * function will be invoked and devres will be freed automatically.
 215  */
 216 void devres_add(struct device *dev, void *res)
 217 {
 218         struct devres *dr = container_of(res, struct devres, data);
 219         unsigned long flags;
 220
 221         spin_lock_irqsave(&dev->devres_lock, flags);
 222         add_dr(dev, &dr->node);
 223         spin_unlock_irqrestore(&dev->devres_lock, flags);
 224 }
 225 EXPORT_SYMBOL_GPL(devres_add);
 226
 227 static struct devres *find_dr(struct device *dev, dr_release_t release,
 228                               dr_match_t match, void *match_data)
 229 {
 230         struct devres_node *node;
 231
 232         list_for_each_entry_reverse(node, &dev->devres_head, entry) {
 233                 struct devres *dr = container_of(node, struct devres, node);
 234
 235                 if (node->release != release)
 236                         continue;
 237                 if (match && !match(dev, dr->data, match_data))
 238                         continue;
 239                 return dr;
 240         }
 241
 242         return NULL;
 243 }
 244
 245 /**
 246  * devres_find - Find device resource
 247  * @dev: Device to lookup resource from
 248  * @release: Look for resources associated with this release function
 249  * @match: Match function (optional)
 250  * @match_data: Data for the match function
 251  *
 252  * Find the latest devres of @dev which is associated with @release
 253  * and for which @match returns 1.  If @match is NULL, it's considered
 254  * to match all.
 255  *
 256  * RETURNS:
 257  * Pointer to found devres, NULL if not found.
 258  */
 259 void * devres_find(struct device *dev, dr_release_t release,
 260                    dr_match_t match, void *match_data)
 261 {
 262         struct devres *dr;
 263         unsigned long flags;
 264
 265         spin_lock_irqsave(&dev->devres_lock, flags);
 266         dr = find_dr(dev, release, match, match_data);
 267         spin_unlock_irqrestore(&dev->devres_lock, flags);
 268
 269         if (dr)
 270                 return dr->data;
 271         return NULL;
 272 }
 273 EXPORT_SYMBOL_GPL(devres_find);
 274
 275 /**
 276  * devres_get - Find devres, if non-existent, add one atomically
 277  * @dev: Device to lookup or add devres for
 278  * @new_res: Pointer to new initialized devres to add if not found
 279  * @match: Match function (optional)
 280  * @match_data: Data for the match function
 281  *
 282  * Find the latest devres of @dev which has the same release function
 283  * as @new_res and for which @match return 1.  If found, @new_res is
 284  * freed; otherwise, @new_res is added atomically.
 285  *
 286  * RETURNS:
 287  * Pointer to found or added devres.
 288  */
 289 void * devres_get(struct device *dev, void *new_res,
 290                   dr_match_t match, void *match_data)
 291 {
 292         struct devres *new_dr = container_of(new_res, struct devres, data);
 293         struct devres *dr;
 294         unsigned long flags;
 295
 296         spin_lock_irqsave(&dev->devres_lock, flags);
 297         dr = find_dr(dev, new_dr->node.release, match, match_data);
 298         if (!dr) {
 299                 add_dr(dev, &new_dr->node);
 300                 dr = new_dr;
 301                 new_res = NULL;
 302         }
 303         spin_unlock_irqrestore(&dev->devres_lock, flags);
 304         devres_free(new_res);
 305
 306         return dr->data;
 307 }
 308 EXPORT_SYMBOL_GPL(devres_get);
 309
 310 /**
 311  * devres_remove - Find a device resource and remove it
 312  * @dev: Device to find resource from
 313  * @release: Look for resources associated with this release function
 314  * @match: Match function (optional)
 315  * @match_data: Data for the match function
 316  *
 317  * Find the latest devres of @dev associated with @release and for
 318  * which @match returns 1.  If @match is NULL, it's considered to
 319  * match all.  If found, the resource is removed atomically and
 320  * returned.
 321  *
 322  * RETURNS:
 323  * Pointer to removed devres on success, NULL if not found.
 324  */
 325 void * devres_remove(struct device *dev, dr_release_t release,
 326                      dr_match_t match, void *match_data)
 327 {
 328         struct devres *dr;
 329         unsigned long flags;
 330
 331         spin_lock_irqsave(&dev->devres_lock, flags);
 332         dr = find_dr(dev, release, match, match_data);
 333         if (dr) {
 334                 list_del_init(&dr->node.entry);
 335                 devres_log(dev, &dr->node, "REM");
 336         }
 337         spin_unlock_irqrestore(&dev->devres_lock, flags);
 338
 339         if (dr)
 340                 return dr->data;
 341         return NULL;
 342 }
 343 EXPORT_SYMBOL_GPL(devres_remove);
 344
 345 /**
 346  * devres_destroy - Find a device resource and destroy it
 347  * @dev: Device to find resource from
 348  * @release: Look for resources associated with this release function
 349  * @match: Match function (optional)
 350  * @match_data: Data for the match function
 351  *
 352  * Find the latest devres of @dev associated with @release and for
 353  * which @match returns 1.  If @match is NULL, it's considered to
 354  * match all.  If found, the resource is removed atomically and freed.
 355  *
 356  * Note that the release function for the resource will not be called,
 357  * only the devres-allocated data will be freed.  The caller becomes
 358  * responsible for freeing any other data.
 359  *
 360  * RETURNS:
 361  * 0 if devres is found and freed, -ENOENT if not found.
 362  */
 363 int devres_destroy(struct device *dev, dr_release_t release,
 364                    dr_match_t match, void *match_data)
 365 {
 366         void *res;
 367
 368         res = devres_remove(dev, release, match, match_data);
 369         if (unlikely(!res))
 370                 return -ENOENT;
 371
 372         devres_free(res);
 373         return 0;
 374 }
 375 EXPORT_SYMBOL_GPL(devres_destroy);
 376
 377
 378 /**
 379  * devres_release - Find a device resource and destroy it, calling release
 380  * @dev: Device to find resource from
 381  * @release: Look for resources associated with this release function
 382  * @match: Match function (optional)
 383  * @match_data: Data for the match function
 384  *
 385  * Find the latest devres of @dev associated with @release and for
 386  * which @match returns 1.  If @match is NULL, it's considered to
 387  * match all.  If found, the resource is removed atomically, the
 388  * release function called and the resource freed.
 389  *
 390  * RETURNS:
 391  * 0 if devres is found and freed, -ENOENT if not found.
 392  */
 393 int devres_release(struct device *dev, dr_release_t release,
 394                    dr_match_t match, void *match_data)
 395 {
 396         void *res;
 397
 398         res = devres_remove(dev, release, match, match_data);
 399         if (unlikely(!res))
 400                 return -ENOENT;
 401
 402         (*release)(dev, res);
 403         devres_free(res);
 404         return 0;
 405 }
 406 EXPORT_SYMBOL_GPL(devres_release);
 407
 408 static int remove_nodes(struct device *dev,
 409                         struct list_head *first, struct list_head *end,
 410                         struct list_head *todo)
 411 {
 412         int cnt = 0, nr_groups = 0;
 413         struct list_head *cur;
 414
 415         /* First pass - move normal devres entries to @todo and clear
 416          * devres_group colors.
 417          */
 418         cur = first;
 419         while (cur != end) {
 420                 struct devres_node *node;
 421                 struct devres_group *grp;
 422
 423                 node = list_entry(cur, struct devres_node, entry);
 424                 cur = cur->next;
 425
 426                 grp = node_to_group(node);
 427                 if (grp) {
 428                         /* clear color of group markers in the first pass */
 429                         grp->color = 0;
 430                         nr_groups++;
 431                 } else {
 432                         /* regular devres entry */
 433                         if (&node->entry == first)
 434                                 first = first->next;
 435                         list_move_tail(&node->entry, todo);
 436                         cnt++;
 437                 }
 438         }
 439
 440         if (!nr_groups)
 441                 return cnt;
 442
 443         /* Second pass - Scan groups and color them.  A group gets
 444          * color value of two iff the group is wholly contained in
 445          * [cur, end).  That is, for a closed group, both opening and
 446          * closing markers should be in the range, while just the
 447          * opening marker is enough for an open group.
 448          */
 449         cur = first;
 450         while (cur != end) {
 451                 struct devres_node *node;
 452                 struct devres_group *grp;
 453
 454                 node = list_entry(cur, struct devres_node, entry);
 455                 cur = cur->next;
 456
 457                 grp = node_to_group(node);
 458                 BUG_ON(!grp || list_empty(&grp->node[0].entry));
 459
 460                 grp->color++;
 461                 if (list_empty(&grp->node[1].entry))
 462                         grp->color++;
 463
 464                 BUG_ON(grp->color <= 0 || grp->color > 2);
 465                 if (grp->color == 2) {
 466                         /* No need to update cur or end.  The removed
 467                          * nodes are always before both.
 468                          */
 469                         list_move_tail(&grp->node[0].entry, todo);
 470                         list_del_init(&grp->node[1].entry);
 471                 }
 472         }
 473
 474         return cnt;
 475 }
 476
 477 static int release_nodes(struct device *dev, struct list_head *first,
 478                          struct list_head *end, unsigned long flags)
 479         __releases(&dev->devres_lock)
 480 {
 481         LIST_HEAD(todo);
 482         int cnt;
 483         struct devres *dr, *tmp;
 484
 485         cnt = remove_nodes(dev, first, end, &todo);
 486
 487         spin_unlock_irqrestore(&dev->devres_lock, flags);
 488
 489         /* Release.  Note that both devres and devres_group are
 490          * handled as devres in the following loop.  This is safe.
 491          */
 492         list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
 493                 devres_log(dev, &dr->node, "REL");
 494                 dr->node.release(dev, dr->data);
 495                 kfree(dr);
 496         }
 497
 498         return cnt;
 499 }
 500
 501 /**
 502  * devres_release_all - Release all managed resources
 503  * @dev: Device to release resources for
 504  *
 505  * Release all resources associated with @dev.  This function is
 506  * called on driver detach.
 507  */
 508 int devres_release_all(struct device *dev)
 509 {
 510         unsigned long flags;
 511
 512         /* Looks like an uninitialized device structure */
 513         if (WARN_ON(dev->devres_head.next == NULL))
 514                 return -ENODEV;
 515         spin_lock_irqsave(&dev->devres_lock, flags);
 516         return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
 517                              flags);
 518 }
 519
 520 /**
 521  * devres_open_group - Open a new devres group
 522  * @dev: Device to open devres group for
 523  * @id: Separator ID
 524  * @gfp: Allocation flags
 525  *
 526  * Open a new devres group for @dev with @id.  For @id, using a
 527  * pointer to an object which won't be used for another group is
 528  * recommended.  If @id is NULL, address-wise unique ID is created.
 529  *
 530  * RETURNS:
 531  * ID of the new group, NULL on failure.
 532  */
 533 void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
 534 {
 535         struct devres_group *grp;
 536         unsigned long flags;
 537
 538         grp = kmalloc(sizeof(*grp), gfp);
 539         if (unlikely(!grp))
 540                 return NULL;
 541
 542         grp->node[0].release = &group_open_release;
 543         grp->node[1].release = &group_close_release;
 544         INIT_LIST_HEAD(&grp->node[0].entry);
 545         INIT_LIST_HEAD(&grp->node[1].entry);
 546         set_node_dbginfo(&grp->node[0], "grp<", 0);
 547         set_node_dbginfo(&grp->node[1], "grp>", 0);
 548         grp->id = grp;
 549         if (id)
 550                 grp->id = id;
 551
 552         spin_lock_irqsave(&dev->devres_lock, flags);
 553         add_dr(dev, &grp->node[0]);
 554         spin_unlock_irqrestore(&dev->devres_lock, flags);
 555         return grp->id;
 556 }
 557 EXPORT_SYMBOL_GPL(devres_open_group);
 558
 559 /* Find devres group with ID @id.  If @id is NULL, look for the latest. */
 560 static struct devres_group * find_group(struct device *dev, void *id)
 561 {
 562         struct devres_node *node;
 563
 564         list_for_each_entry_reverse(node, &dev->devres_head, entry) {
 565                 struct devres_group *grp;
 566
 567                 if (node->release != &group_open_release)
 568                         continue;
 569
 570                 grp = container_of(node, struct devres_group, node[0]);
 571
 572                 if (id) {
 573                         if (grp->id == id)
 574                                 return grp;
 575                 } else if (list_empty(&grp->node[1].entry))
 576                         return grp;
 577         }
 578
 579         return NULL;
 580 }
 581
 582 /**
 583  * devres_close_group - Close a devres group
 584  * @dev: Device to close devres group for
 585  * @id: ID of target group, can be NULL
 586  *
 587  * Close the group identified by @id.  If @id is NULL, the latest open
 588  * group is selected.
 589  */
 590 void devres_close_group(struct device *dev, void *id)
 591 {
 592         struct devres_group *grp;
 593         unsigned long flags;
 594
 595         spin_lock_irqsave(&dev->devres_lock, flags);
 596
 597         grp = find_group(dev, id);
 598         if (grp)
 599                 add_dr(dev, &grp->node[1]);
 600         else
 601                 WARN_ON(1);
 602
 603         spin_unlock_irqrestore(&dev->devres_lock, flags);
 604 }
 605 EXPORT_SYMBOL_GPL(devres_close_group);
 606
 607 /**
 608  * devres_remove_group - Remove a devres group
 609  * @dev: Device to remove group for
 610  * @id: ID of target group, can be NULL
 611  *
 612  * Remove the group identified by @id.  If @id is NULL, the latest
 613  * open group is selected.  Note that removing a group doesn't affect
 614  * any other resources.
 615  */
 616 void devres_remove_group(struct device *dev, void *id)
 617 {
 618         struct devres_group *grp;
 619         unsigned long flags;
 620
 621         spin_lock_irqsave(&dev->devres_lock, flags);
 622
 623         grp = find_group(dev, id);
 624         if (grp) {
 625                 list_del_init(&grp->node[0].entry);
 626                 list_del_init(&grp->node[1].entry);
 627                 devres_log(dev, &grp->node[0], "REM");
 628         } else
 629                 WARN_ON(1);
 630
 631         spin_unlock_irqrestore(&dev->devres_lock, flags);
 632
 633         kfree(grp);
 634 }
 635 EXPORT_SYMBOL_GPL(devres_remove_group);
 636
 637 /**
 638  * devres_release_group - Release resources in a devres group
 639  * @dev: Device to release group for
 640  * @id: ID of target group, can be NULL
 641  *
 642  * Release all resources in the group identified by @id.  If @id is
 643  * NULL, the latest open group is selected.  The selected group and
 644  * groups properly nested inside the selected group are removed.
 645  *
 646  * RETURNS:
 647  * The number of released non-group resources.
 648  */
 649 int devres_release_group(struct device *dev, void *id)
 650 {
 651         struct devres_group *grp;
 652         unsigned long flags;
 653         int cnt = 0;
 654
 655         spin_lock_irqsave(&dev->devres_lock, flags);
 656
 657         grp = find_group(dev, id);
 658         if (grp) {
 659                 struct list_head *first = &grp->node[0].entry;
 660                 struct list_head *end = &dev->devres_head;
 661
 662                 if (!list_empty(&grp->node[1].entry))
 663                         end = grp->node[1].entry.next;
 664
 665                 cnt = release_nodes(dev, first, end, flags);
 666         } else {
 667                 WARN_ON(1);
 668                 spin_unlock_irqrestore(&dev->devres_lock, flags);
 669         }
 670
 671         return cnt;
 672 }
 673 EXPORT_SYMBOL_GPL(devres_release_group);
 674
 675 /*
 676  * Custom devres actions allow inserting a simple function call
 677  * into the teadown sequence.
 678  */
 679
 680 struct action_devres {
 681         void *data;
 682         void (*action)(void *);
 683 };
 684
 685 static int devm_action_match(struct device *dev, void *res, void *p)
 686 {
 687         struct action_devres *devres = res;
 688         struct action_devres *target = p;
 689
 690         return devres->action == target->action &&
 691                devres->data == target->data;
 692 }
 693
 694 static void devm_action_release(struct device *dev, void *res)
 695 {
 696         struct action_devres *devres = res;
 697
 698         devres->action(devres->data);
 699 }
 700
 701 /**
 702  * devm_add_action() - add a custom action to list of managed resources
 703  * @dev: Device that owns the action
 704  * @action: Function that should be called
 705  * @data: Pointer to data passed to @action implementation
 706  *
 707  * This adds a custom action to the list of managed resources so that
 708  * it gets executed as part of standard resource unwinding.
 709  */
 710 int devm_add_action(struct device *dev, void (*action)(void *), void *data)
 711 {
 712         struct action_devres *devres;
 713
 714         devres = devres_alloc(devm_action_release,
 715                               sizeof(struct action_devres), GFP_KERNEL);
 716         if (!devres)
 717                 return -ENOMEM;
 718
 719         devres->data = data;
 720         devres->action = action;
 721
 722         devres_add(dev, devres);
 723         return 0;
 724 }
 725 EXPORT_SYMBOL_GPL(devm_add_action);
 726
 727 /**
 728  * devm_remove_action() - removes previously added custom action
 729  * @dev: Device that owns the action
 730  * @action: Function implementing the action
 731  * @data: Pointer to data passed to @action implementation
 732  *
 733  * Removes instance of @action previously added by devm_add_action().
 734  * Both action and data should match one of the existing entries.
 735  */
 736 void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
 737 {
 738         struct action_devres devres = {
 739                 .data = data,
 740                 .action = action,
 741         };
 742
 743         WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
 744                                &devres));
 745
 746 }
 747 EXPORT_SYMBOL_GPL(devm_remove_action);
 748
 749 /*
 750  * Managed kmalloc/kfree
 751  */
 752 static void devm_kmalloc_release(struct device *dev, void *res)
 753 {
 754         /* noop */
 755 }
 756
 757 static int devm_kmalloc_match(struct device *dev, void *res, void *data)
 758 {
 759         return res == data;
 760 }
 761
 762 /**
 763  * devm_kmalloc - Resource-managed kmalloc
 764  * @dev: Device to allocate memory for
 765  * @size: Allocation size
 766  * @gfp: Allocation gfp flags
 767  *
 768  * Managed kmalloc.  Memory allocated with this function is
 769  * automatically freed on driver detach.  Like all other devres
 770  * resources, guaranteed alignment is unsigned long long.
 771  *
 772  * RETURNS:
 773  * Pointer to allocated memory on success, NULL on failure.
 774  */
 775 void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
 776 {
 777         struct devres *dr;
 778
 779         /* use raw alloc_dr for kmalloc caller tracing */
 780         dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
 781         if (unlikely(!dr))
 782                 return NULL;
 783
 784         /*
 785          * This is named devm_kzalloc_release for historical reasons
 786          * The initial implementation did not support kmalloc, only kzalloc
 787          */
 788         set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
 789         devres_add(dev, dr->data);
 790         return dr->data;
 791 }
 792 EXPORT_SYMBOL_GPL(devm_kmalloc);
 793
 794 /**
 795  * devm_kstrdup - Allocate resource managed space and
 796  *                copy an existing string into that.
 797  * @dev: Device to allocate memory for
 798  * @s: the string to duplicate
 799  * @gfp: the GFP mask used in the devm_kmalloc() call when
 800  *       allocating memory
 801  * RETURNS:
 802  * Pointer to allocated string on success, NULL on failure.
 803  */
 804 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
 805 {
 806         size_t size;
 807         char *buf;
 808
 809         if (!s)
 810                 return NULL;
 811
 812         size = strlen(s) + 1;
 813         buf = devm_kmalloc(dev, size, gfp);
 814         if (buf)
 815                 memcpy(buf, s, size);
 816         return buf;
 817 }
 818 EXPORT_SYMBOL_GPL(devm_kstrdup);
 819
 820 /**
 821  * devm_kvasprintf - Allocate resource managed space and format a string
 822  *                   into that.
 823  * @dev: Device to allocate memory for
 824  * @gfp: the GFP mask used in the devm_kmalloc() call when
 825  *       allocating memory
 826  * @fmt: The printf()-style format string
 827  * @ap: Arguments for the format string
 828  * RETURNS:
 829  * Pointer to allocated string on success, NULL on failure.
 830  */
 831 char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
 832                       va_list ap)
 833 {
 834         unsigned int len;
 835         char *p;
 836         va_list aq;
 837
 838         va_copy(aq, ap);
 839         len = vsnprintf(NULL, 0, fmt, aq);
 840         va_end(aq);
 841
 842         p = devm_kmalloc(dev, len+1, gfp);
 843         if (!p)
 844                 return NULL;
 845
 846         vsnprintf(p, len+1, fmt, ap);
 847
 848         return p;
 849 }
 850 EXPORT_SYMBOL(devm_kvasprintf);
 851
 852 /**
 853  * devm_kasprintf - Allocate resource managed space and format a string
 854  *                  into that.
 855  * @dev: Device to allocate memory for
 856  * @gfp: the GFP mask used in the devm_kmalloc() call when
 857  *       allocating memory
 858  * @fmt: The printf()-style format string
 859  * @...: Arguments for the format string
 860  * RETURNS:
 861  * Pointer to allocated string on success, NULL on failure.
 862  */
 863 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
 864 {
 865         va_list ap;
 866         char *p;
 867
 868         va_start(ap, fmt);
 869         p = devm_kvasprintf(dev, gfp, fmt, ap);
 870         va_end(ap);
 871
 872         return p;
 873 }
 874 EXPORT_SYMBOL_GPL(devm_kasprintf);
 875
 876 /**
 877  * devm_kfree - Resource-managed kfree
 878  * @dev: Device this memory belongs to
 879  * @p: Memory to free
 880  *
 881  * Free memory allocated with devm_kmalloc().
 882  */
 883 void devm_kfree(struct device *dev, void *p)
 884 {
 885         int rc;
 886
 887         rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
 888         WARN_ON(rc);
 889 }
 890 EXPORT_SYMBOL_GPL(devm_kfree);
 891
 892 /**
 893  * devm_kmemdup - Resource-managed kmemdup
 894  * @dev: Device this memory belongs to
 895  * @src: Memory region to duplicate
 896  * @len: Memory region length
 897  * @gfp: GFP mask to use
 898  *
 899  * Duplicate region of a memory using resource managed kmalloc
 900  */
 901 void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
 902 {
 903         void *p;
 904
 905         p = devm_kmalloc(dev, len, gfp);
 906         if (p)
 907                 memcpy(p, src, len);
 908
 909         return p;
 910 }
 911 EXPORT_SYMBOL_GPL(devm_kmemdup);
 912
 913 struct pages_devres {
 914         unsigned long addr;
 915         unsigned int order;
 916 };
 917
 918 static int devm_pages_match(struct device *dev, void *res, void *p)
 919 {
 920         struct pages_devres *devres = res;
 921         struct pages_devres *target = p;
 922
 923         return devres->addr == target->addr;
 924 }
 925
 926 static void devm_pages_release(struct device *dev, void *res)
 927 {
 928         struct pages_devres *devres = res;
 929
 930         free_pages(devres->addr, devres->order);
 931 }
 932
 933 /**
 934  * devm_get_free_pages - Resource-managed __get_free_pages
 935  * @dev: Device to allocate memory for
 936  * @gfp_mask: Allocation gfp flags
 937  * @order: Allocation size is (1 << order) pages
 938  *
 939  * Managed get_free_pages.  Memory allocated with this function is
 940  * automatically freed on driver detach.
 941  *
 942  * RETURNS:
 943  * Address of allocated memory on success, 0 on failure.
 944  */
 945
 946 unsigned long devm_get_free_pages(struct device *dev,
 947                                   gfp_t gfp_mask, unsigned int order)
 948 {
 949         struct pages_devres *devres;
 950         unsigned long addr;
 951
 952         addr = __get_free_pages(gfp_mask, order);
 953
 954         if (unlikely(!addr))
 955                 return 0;
 956
 957         devres = devres_alloc(devm_pages_release,
 958                               sizeof(struct pages_devres), GFP_KERNEL);
 959         if (unlikely(!devres)) {
 960                 free_pages(addr, order);
 961                 return 0;
 962         }
 963
 964         devres->addr = addr;
 965         devres->order = order;
 966
 967         devres_add(dev, devres);
 968         return addr;
 969 }
 970 EXPORT_SYMBOL_GPL(devm_get_free_pages);
 971
 972 /**
 973  * devm_free_pages - Resource-managed free_pages
 974  * @dev: Device this memory belongs to
 975  * @addr: Memory to free
 976  *
 977  * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
 978  * there is no need to supply the @order.
 979  */
 980 void devm_free_pages(struct device *dev, unsigned long addr)
 981 {
 982         struct pages_devres devres = { .addr = addr };
 983
 984         WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
 985                                &devres));
 986 }
 987 EXPORT_SYMBOL_GPL(devm_free_pages);