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)
  86 {
  87         size_t tot_size = sizeof(struct devres) + size;
  88         struct devres *dr;
  89
  90         dr = kmalloc_track_caller(tot_size, gfp);
  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(dr_release_t release, size_t size, gfp_t gfp,
 110                       const char *name)
 111 {
 112         struct devres *dr;
 113
 114         dr = alloc_dr(release, size, gfp | __GFP_ZERO);
 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);
 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  *
 128  * Allocate devres of @size bytes.  The allocated area is zeroed, then
 129  * associated with @release.  The returned pointer can be passed to
 130  * other devres_*() functions.
 131  *
 132  * RETURNS:
 133  * Pointer to allocated devres on success, NULL on failure.
 134  */
 135 void * devres_alloc(dr_release_t release, size_t size, gfp_t gfp)
 136 {
 137         struct devres *dr;
 138
 139         dr = alloc_dr(release, size, gfp | __GFP_ZERO);
 140         if (unlikely(!dr))
 141                 return NULL;
 142         return dr->data;
 143 }
 144 EXPORT_SYMBOL_GPL(devres_alloc);
 145 #endif
 146
 147 /**
 148  * devres_for_each_res - Resource iterator
 149  * @dev: Device to iterate resource from
 150  * @release: Look for resources associated with this release function
 151  * @match: Match function (optional)
 152  * @match_data: Data for the match function
 153  * @fn: Function to be called for each matched resource.
 154  * @data: Data for @fn, the 3rd parameter of @fn
 155  *
 156  * Call @fn for each devres of @dev which is associated with @release
 157  * and for which @match returns 1.
 158  *
 159  * RETURNS:
 160  *      void
 161  */
 162 void devres_for_each_res(struct device *dev, dr_release_t release,
 163                         dr_match_t match, void *match_data,
 164                         void (*fn)(struct device *, void *, void *),
 165                         void *data)
 166 {
 167         struct devres_node *node;
 168         struct devres_node *tmp;
 169         unsigned long flags;
 170
 171         if (!fn)
 172                 return;
 173
 174         spin_lock_irqsave(&dev->devres_lock, flags);
 175         list_for_each_entry_safe_reverse(node, tmp,
 176                         &dev->devres_head, entry) {
 177                 struct devres *dr = container_of(node, struct devres, node);
 178
 179                 if (node->release != release)
 180                         continue;
 181                 if (match && !match(dev, dr->data, match_data))
 182                         continue;
 183                 fn(dev, dr->data, data);
 184         }
 185         spin_unlock_irqrestore(&dev->devres_lock, flags);
 186 }
 187 EXPORT_SYMBOL_GPL(devres_for_each_res);
 188
 189 /**
 190  * devres_free - Free device resource data
 191  * @res: Pointer to devres data to free
 192  *
 193  * Free devres created with devres_alloc().
 194  */
 195 void devres_free(void *res)
 196 {
 197         if (res) {
 198                 struct devres *dr = container_of(res, struct devres, data);
 199
 200                 BUG_ON(!list_empty(&dr->node.entry));
 201                 kfree(dr);
 202         }
 203 }
 204 EXPORT_SYMBOL_GPL(devres_free);
 205
 206 /**
 207  * devres_add - Register device resource
 208  * @dev: Device to add resource to
 209  * @res: Resource to register
 210  *
 211  * Register devres @res to @dev.  @res should have been allocated
 212  * using devres_alloc().  On driver detach, the associated release
 213  * function will be invoked and devres will be freed automatically.
 214  */
 215 void devres_add(struct device *dev, void *res)
 216 {
 217         struct devres *dr = container_of(res, struct devres, data);
 218         unsigned long flags;
 219
 220         spin_lock_irqsave(&dev->devres_lock, flags);
 221         add_dr(dev, &dr->node);
 222         spin_unlock_irqrestore(&dev->devres_lock, flags);
 223 }
 224 EXPORT_SYMBOL_GPL(devres_add);
 225
 226 static struct devres *find_dr(struct device *dev, dr_release_t release,
 227                               dr_match_t match, void *match_data)
 228 {
 229         struct devres_node *node;
 230
 231         list_for_each_entry_reverse(node, &dev->devres_head, entry) {
 232                 struct devres *dr = container_of(node, struct devres, node);
 233
 234                 if (node->release != release)
 235                         continue;
 236                 if (match && !match(dev, dr->data, match_data))
 237                         continue;
 238                 return dr;
 239         }
 240
 241         return NULL;
 242 }
 243
 244 /**
 245  * devres_find - Find device resource
 246  * @dev: Device to lookup resource from
 247  * @release: Look for resources associated with this release function
 248  * @match: Match function (optional)
 249  * @match_data: Data for the match function
 250  *
 251  * Find the latest devres of @dev which is associated with @release
 252  * and for which @match returns 1.  If @match is NULL, it's considered
 253  * to match all.
 254  *
 255  * RETURNS:
 256  * Pointer to found devres, NULL if not found.
 257  */
 258 void * devres_find(struct device *dev, dr_release_t release,
 259                    dr_match_t match, void *match_data)
 260 {
 261         struct devres *dr;
 262         unsigned long flags;
 263
 264         spin_lock_irqsave(&dev->devres_lock, flags);
 265         dr = find_dr(dev, release, match, match_data);
 266         spin_unlock_irqrestore(&dev->devres_lock, flags);
 267
 268         if (dr)
 269                 return dr->data;
 270         return NULL;
 271 }
 272 EXPORT_SYMBOL_GPL(devres_find);
 273
 274 /**
 275  * devres_get - Find devres, if non-existent, add one atomically
 276  * @dev: Device to lookup or add devres for
 277  * @new_res: Pointer to new initialized devres to add if not found
 278  * @match: Match function (optional)
 279  * @match_data: Data for the match function
 280  *
 281  * Find the latest devres of @dev which has the same release function
 282  * as @new_res and for which @match return 1.  If found, @new_res is
 283  * freed; otherwise, @new_res is added atomically.
 284  *
 285  * RETURNS:
 286  * Pointer to found or added devres.
 287  */
 288 void * devres_get(struct device *dev, void *new_res,
 289                   dr_match_t match, void *match_data)
 290 {
 291         struct devres *new_dr = container_of(new_res, struct devres, data);
 292         struct devres *dr;
 293         unsigned long flags;
 294
 295         spin_lock_irqsave(&dev->devres_lock, flags);
 296         dr = find_dr(dev, new_dr->node.release, match, match_data);
 297         if (!dr) {
 298                 add_dr(dev, &new_dr->node);
 299                 dr = new_dr;
 300                 new_dr = NULL;
 301         }
 302         spin_unlock_irqrestore(&dev->devres_lock, flags);
 303         devres_free(new_dr);
 304
 305         return dr->data;
 306 }
 307 EXPORT_SYMBOL_GPL(devres_get);
 308
 309 /**
 310  * devres_remove - Find a device resource and remove it
 311  * @dev: Device to find resource from
 312  * @release: Look for resources associated with this release function
 313  * @match: Match function (optional)
 314  * @match_data: Data for the match function
 315  *
 316  * Find the latest devres of @dev associated with @release and for
 317  * which @match returns 1.  If @match is NULL, it's considered to
 318  * match all.  If found, the resource is removed atomically and
 319  * returned.
 320  *
 321  * RETURNS:
 322  * Pointer to removed devres on success, NULL if not found.
 323  */
 324 void * devres_remove(struct device *dev, dr_release_t release,
 325                      dr_match_t match, void *match_data)
 326 {
 327         struct devres *dr;
 328         unsigned long flags;
 329
 330         spin_lock_irqsave(&dev->devres_lock, flags);
 331         dr = find_dr(dev, release, match, match_data);
 332         if (dr) {
 333                 list_del_init(&dr->node.entry);
 334                 devres_log(dev, &dr->node, "REM");
 335         }
 336         spin_unlock_irqrestore(&dev->devres_lock, flags);
 337
 338         if (dr)
 339                 return dr->data;
 340         return NULL;
 341 }
 342 EXPORT_SYMBOL_GPL(devres_remove);
 343
 344 /**
 345  * devres_destroy - Find a device resource and destroy it
 346  * @dev: Device to find resource from
 347  * @release: Look for resources associated with this release function
 348  * @match: Match function (optional)
 349  * @match_data: Data for the match function
 350  *
 351  * Find the latest devres of @dev associated with @release and for
 352  * which @match returns 1.  If @match is NULL, it's considered to
 353  * match all.  If found, the resource is removed atomically and freed.
 354  *
 355  * Note that the release function for the resource will not be called,
 356  * only the devres-allocated data will be freed.  The caller becomes
 357  * responsible for freeing any other data.
 358  *
 359  * RETURNS:
 360  * 0 if devres is found and freed, -ENOENT if not found.
 361  */
 362 int devres_destroy(struct device *dev, dr_release_t release,
 363                    dr_match_t match, void *match_data)
 364 {
 365         void *res;
 366
 367         res = devres_remove(dev, release, match, match_data);
 368         if (unlikely(!res))
 369                 return -ENOENT;
 370
 371         devres_free(res);
 372         return 0;
 373 }
 374 EXPORT_SYMBOL_GPL(devres_destroy);
 375
 376
 377 /**
 378  * devres_release - Find a device resource and destroy it, calling release
 379  * @dev: Device to find resource from
 380  * @release: Look for resources associated with this release function
 381  * @match: Match function (optional)
 382  * @match_data: Data for the match function
 383  *
 384  * Find the latest devres of @dev associated with @release and for
 385  * which @match returns 1.  If @match is NULL, it's considered to
 386  * match all.  If found, the resource is removed atomically, the
 387  * release function called and the resource freed.
 388  *
 389  * RETURNS:
 390  * 0 if devres is found and freed, -ENOENT if not found.
 391  */
 392 int devres_release(struct device *dev, dr_release_t release,
 393                    dr_match_t match, void *match_data)
 394 {
 395         void *res;
 396
 397         res = devres_remove(dev, release, match, match_data);
 398         if (unlikely(!res))
 399                 return -ENOENT;
 400
 401         (*release)(dev, res);
 402         devres_free(res);
 403         return 0;
 404 }
 405 EXPORT_SYMBOL_GPL(devres_release);
 406
 407 static int remove_nodes(struct device *dev,
 408                         struct list_head *first, struct list_head *end,
 409                         struct list_head *todo)
 410 {
 411         int cnt = 0, nr_groups = 0;
 412         struct list_head *cur;
 413
 414         /* First pass - move normal devres entries to @todo and clear
 415          * devres_group colors.
 416          */
 417         cur = first;
 418         while (cur != end) {
 419                 struct devres_node *node;
 420                 struct devres_group *grp;
 421
 422                 node = list_entry(cur, struct devres_node, entry);
 423                 cur = cur->next;
 424
 425                 grp = node_to_group(node);
 426                 if (grp) {
 427                         /* clear color of group markers in the first pass */
 428                         grp->color = 0;
 429                         nr_groups++;
 430                 } else {
 431                         /* regular devres entry */
 432                         if (&node->entry == first)
 433                                 first = first->next;
 434                         list_move_tail(&node->entry, todo);
 435                         cnt++;
 436                 }
 437         }
 438
 439         if (!nr_groups)
 440                 return cnt;
 441
 442         /* Second pass - Scan groups and color them.  A group gets
 443          * color value of two iff the group is wholly contained in
 444          * [cur, end).  That is, for a closed group, both opening and
 445          * closing markers should be in the range, while just the
 446          * opening marker is enough for an open group.
 447          */
 448         cur = first;
 449         while (cur != end) {
 450                 struct devres_node *node;
 451                 struct devres_group *grp;
 452
 453                 node = list_entry(cur, struct devres_node, entry);
 454                 cur = cur->next;
 455
 456                 grp = node_to_group(node);
 457                 BUG_ON(!grp || list_empty(&grp->node[0].entry));
 458
 459                 grp->color++;
 460                 if (list_empty(&grp->node[1].entry))
 461                         grp->color++;
 462
 463                 BUG_ON(grp->color <= 0 || grp->color > 2);
 464                 if (grp->color == 2) {
 465                         /* No need to update cur or end.  The removed
 466                          * nodes are always before both.
 467                          */
 468                         list_move_tail(&grp->node[0].entry, todo);
 469                         list_del_init(&grp->node[1].entry);
 470                 }
 471         }
 472
 473         return cnt;
 474 }
 475
 476 static int release_nodes(struct device *dev, struct list_head *first,
 477                          struct list_head *end, unsigned long flags)
 478         __releases(&dev->devres_lock)
 479 {
 480         LIST_HEAD(todo);
 481         int cnt;
 482         struct devres *dr, *tmp;
 483
 484         cnt = remove_nodes(dev, first, end, &todo);
 485
 486         spin_unlock_irqrestore(&dev->devres_lock, flags);
 487
 488         /* Release.  Note that both devres and devres_group are
 489          * handled as devres in the following loop.  This is safe.
 490          */
 491         list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
 492                 devres_log(dev, &dr->node, "REL");
 493                 dr->node.release(dev, dr->data);
 494                 kfree(dr);
 495         }
 496
 497         return cnt;
 498 }
 499
 500 /**
 501  * devres_release_all - Release all managed resources
 502  * @dev: Device to release resources for
 503  *
 504  * Release all resources associated with @dev.  This function is
 505  * called on driver detach.
 506  */
 507 int devres_release_all(struct device *dev)
 508 {
 509         unsigned long flags;
 510
 511         /* Looks like an uninitialized device structure */
 512         if (WARN_ON(dev->devres_head.next == NULL))
 513                 return -ENODEV;
 514         spin_lock_irqsave(&dev->devres_lock, flags);
 515         return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
 516                              flags);
 517 }
 518
 519 /**
 520  * devres_open_group - Open a new devres group
 521  * @dev: Device to open devres group for
 522  * @id: Separator ID
 523  * @gfp: Allocation flags
 524  *
 525  * Open a new devres group for @dev with @id.  For @id, using a
 526  * pointer to an object which won't be used for another group is
 527  * recommended.  If @id is NULL, address-wise unique ID is created.
 528  *
 529  * RETURNS:
 530  * ID of the new group, NULL on failure.
 531  */
 532 void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
 533 {
 534         struct devres_group *grp;
 535         unsigned long flags;
 536
 537         grp = kmalloc(sizeof(*grp), gfp);
 538         if (unlikely(!grp))
 539                 return NULL;
 540
 541         grp->node[0].release = &group_open_release;
 542         grp->node[1].release = &group_close_release;
 543         INIT_LIST_HEAD(&grp->node[0].entry);
 544         INIT_LIST_HEAD(&grp->node[1].entry);
 545         set_node_dbginfo(&grp->node[0], "grp<", 0);
 546         set_node_dbginfo(&grp->node[1], "grp>", 0);
 547         grp->id = grp;
 548         if (id)
 549                 grp->id = id;
 550
 551         spin_lock_irqsave(&dev->devres_lock, flags);
 552         add_dr(dev, &grp->node[0]);
 553         spin_unlock_irqrestore(&dev->devres_lock, flags);
 554         return grp->id;
 555 }
 556 EXPORT_SYMBOL_GPL(devres_open_group);
 557
 558 /* Find devres group with ID @id.  If @id is NULL, look for the latest. */
 559 static struct devres_group * find_group(struct device *dev, void *id)
 560 {
 561         struct devres_node *node;
 562
 563         list_for_each_entry_reverse(node, &dev->devres_head, entry) {
 564                 struct devres_group *grp;
 565
 566                 if (node->release != &group_open_release)
 567                         continue;
 568
 569                 grp = container_of(node, struct devres_group, node[0]);
 570
 571                 if (id) {
 572                         if (grp->id == id)
 573                                 return grp;
 574                 } else if (list_empty(&grp->node[1].entry))
 575                         return grp;
 576         }
 577
 578         return NULL;
 579 }
 580
 581 /**
 582  * devres_close_group - Close a devres group
 583  * @dev: Device to close devres group for
 584  * @id: ID of target group, can be NULL
 585  *
 586  * Close the group identified by @id.  If @id is NULL, the latest open
 587  * group is selected.
 588  */
 589 void devres_close_group(struct device *dev, void *id)
 590 {
 591         struct devres_group *grp;
 592         unsigned long flags;
 593
 594         spin_lock_irqsave(&dev->devres_lock, flags);
 595
 596         grp = find_group(dev, id);
 597         if (grp)
 598                 add_dr(dev, &grp->node[1]);
 599         else
 600                 WARN_ON(1);
 601
 602         spin_unlock_irqrestore(&dev->devres_lock, flags);
 603 }
 604 EXPORT_SYMBOL_GPL(devres_close_group);
 605
 606 /**
 607  * devres_remove_group - Remove a devres group
 608  * @dev: Device to remove group for
 609  * @id: ID of target group, can be NULL
 610  *
 611  * Remove the group identified by @id.  If @id is NULL, the latest
 612  * open group is selected.  Note that removing a group doesn't affect
 613  * any other resources.
 614  */
 615 void devres_remove_group(struct device *dev, void *id)
 616 {
 617         struct devres_group *grp;
 618         unsigned long flags;
 619
 620         spin_lock_irqsave(&dev->devres_lock, flags);
 621
 622         grp = find_group(dev, id);
 623         if (grp) {
 624                 list_del_init(&grp->node[0].entry);
 625                 list_del_init(&grp->node[1].entry);
 626                 devres_log(dev, &grp->node[0], "REM");
 627         } else
 628                 WARN_ON(1);
 629
 630         spin_unlock_irqrestore(&dev->devres_lock, flags);
 631
 632         kfree(grp);
 633 }
 634 EXPORT_SYMBOL_GPL(devres_remove_group);
 635
 636 /**
 637  * devres_release_group - Release resources in a devres group
 638  * @dev: Device to release group for
 639  * @id: ID of target group, can be NULL
 640  *
 641  * Release all resources in the group identified by @id.  If @id is
 642  * NULL, the latest open group is selected.  The selected group and
 643  * groups properly nested inside the selected group are removed.
 644  *
 645  * RETURNS:
 646  * The number of released non-group resources.
 647  */
 648 int devres_release_group(struct device *dev, void *id)
 649 {
 650         struct devres_group *grp;
 651         unsigned long flags;
 652         int cnt = 0;
 653
 654         spin_lock_irqsave(&dev->devres_lock, flags);
 655
 656         grp = find_group(dev, id);
 657         if (grp) {
 658                 struct list_head *first = &grp->node[0].entry;
 659                 struct list_head *end = &dev->devres_head;
 660
 661                 if (!list_empty(&grp->node[1].entry))
 662                         end = grp->node[1].entry.next;
 663
 664                 cnt = release_nodes(dev, first, end, flags);
 665         } else {
 666                 WARN_ON(1);
 667                 spin_unlock_irqrestore(&dev->devres_lock, flags);
 668         }
 669
 670         return cnt;
 671 }
 672 EXPORT_SYMBOL_GPL(devres_release_group);
 673
 674 /*
 675  * Custom devres actions allow inserting a simple function call
 676  * into the teadown sequence.
 677  */
 678
 679 struct action_devres {
 680         void *data;
 681         void (*action)(void *);
 682 };
 683
 684 static int devm_action_match(struct device *dev, void *res, void *p)
 685 {
 686         struct action_devres *devres = res;
 687         struct action_devres *target = p;
 688
 689         return devres->action == target->action &&
 690                devres->data == target->data;
 691 }
 692
 693 static void devm_action_release(struct device *dev, void *res)
 694 {
 695         struct action_devres *devres = res;
 696
 697         devres->action(devres->data);
 698 }
 699
 700 /**
 701  * devm_add_action() - add a custom action to list of managed resources
 702  * @dev: Device that owns the action
 703  * @action: Function that should be called
 704  * @data: Pointer to data passed to @action implementation
 705  *
 706  * This adds a custom action to the list of managed resources so that
 707  * it gets executed as part of standard resource unwinding.
 708  */
 709 int devm_add_action(struct device *dev, void (*action)(void *), void *data)
 710 {
 711         struct action_devres *devres;
 712
 713         devres = devres_alloc(devm_action_release,
 714                               sizeof(struct action_devres), GFP_KERNEL);
 715         if (!devres)
 716                 return -ENOMEM;
 717
 718         devres->data = data;
 719         devres->action = action;
 720
 721         devres_add(dev, devres);
 722         return 0;
 723 }
 724 EXPORT_SYMBOL_GPL(devm_add_action);
 725
 726 /**
 727  * devm_remove_action() - removes previously added custom action
 728  * @dev: Device that owns the action
 729  * @action: Function implementing the action
 730  * @data: Pointer to data passed to @action implementation
 731  *
 732  * Removes instance of @action previously added by devm_add_action().
 733  * Both action and data should match one of the existing entries.
 734  */
 735 void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
 736 {
 737         struct action_devres devres = {
 738                 .data = data,
 739                 .action = action,
 740         };
 741
 742         WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
 743                                &devres));
 744
 745 }
 746 EXPORT_SYMBOL_GPL(devm_remove_action);
 747
 748 /*
 749  * Managed kmalloc/kfree
 750  */
 751 static void devm_kmalloc_release(struct device *dev, void *res)
 752 {
 753         /* noop */
 754 }
 755
 756 static int devm_kmalloc_match(struct device *dev, void *res, void *data)
 757 {
 758         return res == data;
 759 }
 760
 761 /**
 762  * devm_kmalloc - Resource-managed kmalloc
 763  * @dev: Device to allocate memory for
 764  * @size: Allocation size
 765  * @gfp: Allocation gfp flags
 766  *
 767  * Managed kmalloc.  Memory allocated with this function is
 768  * automatically freed on driver detach.  Like all other devres
 769  * resources, guaranteed alignment is unsigned long long.
 770  *
 771  * RETURNS:
 772  * Pointer to allocated memory on success, NULL on failure.
 773  */
 774 void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
 775 {
 776         struct devres *dr;
 777
 778         /* use raw alloc_dr for kmalloc caller tracing */
 779         dr = alloc_dr(devm_kmalloc_release, size, gfp);
 780         if (unlikely(!dr))
 781                 return NULL;
 782
 783         /*
 784          * This is named devm_kzalloc_release for historical reasons
 785          * The initial implementation did not support kmalloc, only kzalloc
 786          */
 787         set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
 788         devres_add(dev, dr->data);
 789         return dr->data;
 790 }
 791 EXPORT_SYMBOL_GPL(devm_kmalloc);
 792
 793 /**
 794  * devm_kfree - Resource-managed kfree
 795  * @dev: Device this memory belongs to
 796  * @p: Memory to free
 797  *
 798  * Free memory allocated with devm_kmalloc().
 799  */
 800 void devm_kfree(struct device *dev, void *p)
 801 {
 802         int rc;
 803
 804         rc = devres_destroy(dev, devm_kmalloc_release, devm_kmalloc_match, p);
 805         WARN_ON(rc);
 806 }
 807 EXPORT_SYMBOL_GPL(devm_kfree);