drivers/base/devres.c

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This source file includes following definitions.
set_node_dbginfo
devres_log
group_open_release
group_close_release
node_to_group
alloc_dr
add_dr
__devres_alloc_node
devres_alloc_node
devres_for_each_res
devres_free
devres_add
find_dr
devres_find
devres_get
devres_remove
devres_destroy
devres_release
remove_nodes
release_nodes
devres_release_all
devres_open_group
find_group
devres_close_group
devres_remove_group
devres_release_group
devm_action_match
devm_action_release
devm_add_action
devm_remove_action
devm_release_action
devm_kmalloc_release
devm_kmalloc_match
devm_kmalloc
devm_kstrdup
devm_kstrdup_const
devm_kvasprintf
devm_kasprintf
devm_kfree
devm_kmemdup
devm_pages_match
devm_pages_release
devm_get_free_pages
devm_free_pages
devm_percpu_release
devm_percpu_match
__devm_alloc_percpu
devm_free_percpu
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * drivers/base/devres.c - device resource management
   4  *
   5  * Copyright (c) 2006  SUSE Linux Products GmbH
   6  * Copyright (c) 2006  Tejun Heo <teheo@suse.de>
   7  */
   8 
   9 #include <linux/device.h>
  10 #include <linux/module.h>
  11 #include <linux/slab.h>
  12 #include <linux/percpu.h>
  13 
  14 #include <asm/sections.h>
  15 
  16 #include "base.h"
  17 
  18 struct devres_node {
  19         struct list_head                entry;
  20         dr_release_t                    release;
  21 #ifdef CONFIG_DEBUG_DEVRES
  22         const char                      *name;
  23         size_t                          size;
  24 #endif
  25 };
  26 
  27 struct devres {
  28         struct devres_node              node;
  29         /*
  30          * Some archs want to perform DMA into kmalloc caches
  31          * and need a guaranteed alignment larger than
  32          * the alignment of a 64-bit integer.
  33          * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
  34          * buffer alignment as if it was allocated by plain kmalloc().
  35          */
  36         u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
  37 };
  38 
  39 struct devres_group {
  40         struct devres_node              node[2];
  41         void                            *id;
  42         int                             color;
  43         /* -- 8 pointers */
  44 };
  45 
  46 #ifdef CONFIG_DEBUG_DEVRES
  47 static int log_devres = 0;
  48 module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);
  49 
  50 static void set_node_dbginfo(struct devres_node *node, const char *name,
  51                              size_t size)
  52 {
  53         node->name = name;
  54         node->size = size;
  55 }
  56 
  57 static void devres_log(struct device *dev, struct devres_node *node,
  58                        const char *op)
  59 {
  60         if (unlikely(log_devres))
  61                 dev_err(dev, "DEVRES %3s %p %s (%lu bytes)\n",
  62                         op, node, node->name, (unsigned long)node->size);
  63 }
  64 #else /* CONFIG_DEBUG_DEVRES */
  65 #define set_node_dbginfo(node, n, s)    do {} while (0)
  66 #define devres_log(dev, node, op)       do {} while (0)
  67 #endif /* CONFIG_DEBUG_DEVRES */
  68 
  69 /*
  70  * Release functions for devres group.  These callbacks are used only
  71  * for identification.
  72  */
  73 static void group_open_release(struct device *dev, void *res)
  74 {
  75         /* noop */
  76 }
  77 
  78 static void group_close_release(struct device *dev, void *res)
  79 {
  80         /* noop */
  81 }
  82 
  83 static struct devres_group * node_to_group(struct devres_node *node)
  84 {
  85         if (node->release == &group_open_release)
  86                 return container_of(node, struct devres_group, node[0]);
  87         if (node->release == &group_close_release)
  88                 return container_of(node, struct devres_group, node[1]);
  89         return NULL;
  90 }
  91 
  92 static __always_inline struct devres * alloc_dr(dr_release_t release,
  93                                                 size_t size, gfp_t gfp, int nid)
  94 {
  95         size_t tot_size;
  96         struct devres *dr;
  97 
  98         /* We must catch any near-SIZE_MAX cases that could overflow. */
  99         if (unlikely(check_add_overflow(sizeof(struct devres), size,
 100                                         &tot_size)))
 101                 return NULL;
 102 
 103         dr = kmalloc_node_track_caller(tot_size, gfp, nid);
 104         if (unlikely(!dr))
 105                 return NULL;
 106 
 107         memset(dr, 0, offsetof(struct devres, data));
 108 
 109         INIT_LIST_HEAD(&dr->node.entry);
 110         dr->node.release = release;
 111         return dr;
 112 }
 113 
 114 static void add_dr(struct device *dev, struct devres_node *node)
 115 {
 116         devres_log(dev, node, "ADD");
 117         BUG_ON(!list_empty(&node->entry));
 118         list_add_tail(&node->entry, &dev->devres_head);
 119 }
 120 
 121 #ifdef CONFIG_DEBUG_DEVRES
 122 void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,
 123                       const char *name)
 124 {
 125         struct devres *dr;
 126 
 127         dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
 128         if (unlikely(!dr))
 129                 return NULL;
 130         set_node_dbginfo(&dr->node, name, size);
 131         return dr->data;
 132 }
 133 EXPORT_SYMBOL_GPL(__devres_alloc_node);
 134 #else
 135 /**
 136  * devres_alloc - Allocate device resource data
 137  * @release: Release function devres will be associated with
 138  * @size: Allocation size
 139  * @gfp: Allocation flags
 140  * @nid: NUMA node
 141  *
 142  * Allocate devres of @size bytes.  The allocated area is zeroed, then
 143  * associated with @release.  The returned pointer can be passed to
 144  * other devres_*() functions.
 145  *
 146  * RETURNS:
 147  * Pointer to allocated devres on success, NULL on failure.
 148  */
 149 void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)
 150 {
 151         struct devres *dr;
 152 
 153         dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
 154         if (unlikely(!dr))
 155                 return NULL;
 156         return dr->data;
 157 }
 158 EXPORT_SYMBOL_GPL(devres_alloc_node);
 159 #endif
 160 
 161 /**
 162  * devres_for_each_res - Resource iterator
 163  * @dev: Device to iterate resource from
 164  * @release: Look for resources associated with this release function
 165  * @match: Match function (optional)
 166  * @match_data: Data for the match function
 167  * @fn: Function to be called for each matched resource.
 168  * @data: Data for @fn, the 3rd parameter of @fn
 169  *
 170  * Call @fn for each devres of @dev which is associated with @release
 171  * and for which @match returns 1.
 172  *
 173  * RETURNS:
 174  *      void
 175  */
 176 void devres_for_each_res(struct device *dev, dr_release_t release,
 177                         dr_match_t match, void *match_data,
 178                         void (*fn)(struct device *, void *, void *),
 179                         void *data)
 180 {
 181         struct devres_node *node;
 182         struct devres_node *tmp;
 183         unsigned long flags;
 184 
 185         if (!fn)
 186                 return;
 187 
 188         spin_lock_irqsave(&dev->devres_lock, flags);
 189         list_for_each_entry_safe_reverse(node, tmp,
 190                         &dev->devres_head, entry) {
 191                 struct devres *dr = container_of(node, struct devres, node);
 192 
 193                 if (node->release != release)
 194                         continue;
 195                 if (match && !match(dev, dr->data, match_data))
 196                         continue;
 197                 fn(dev, dr->data, data);
 198         }
 199         spin_unlock_irqrestore(&dev->devres_lock, flags);
 200 }
 201 EXPORT_SYMBOL_GPL(devres_for_each_res);
 202 
 203 /**
 204  * devres_free - Free device resource data
 205  * @res: Pointer to devres data to free
 206  *
 207  * Free devres created with devres_alloc().
 208  */
 209 void devres_free(void *res)
 210 {
 211         if (res) {
 212                 struct devres *dr = container_of(res, struct devres, data);
 213 
 214                 BUG_ON(!list_empty(&dr->node.entry));
 215                 kfree(dr);
 216         }
 217 }
 218 EXPORT_SYMBOL_GPL(devres_free);
 219 
 220 /**
 221  * devres_add - Register device resource
 222  * @dev: Device to add resource to
 223  * @res: Resource to register
 224  *
 225  * Register devres @res to @dev.  @res should have been allocated
 226  * using devres_alloc().  On driver detach, the associated release
 227  * function will be invoked and devres will be freed automatically.
 228  */
 229 void devres_add(struct device *dev, void *res)
 230 {
 231         struct devres *dr = container_of(res, struct devres, data);
 232         unsigned long flags;
 233 
 234         spin_lock_irqsave(&dev->devres_lock, flags);
 235         add_dr(dev, &dr->node);
 236         spin_unlock_irqrestore(&dev->devres_lock, flags);
 237 }
 238 EXPORT_SYMBOL_GPL(devres_add);
 239 
 240 static struct devres *find_dr(struct device *dev, dr_release_t release,
 241                               dr_match_t match, void *match_data)
 242 {
 243         struct devres_node *node;
 244 
 245         list_for_each_entry_reverse(node, &dev->devres_head, entry) {
 246                 struct devres *dr = container_of(node, struct devres, node);
 247 
 248                 if (node->release != release)
 249                         continue;
 250                 if (match && !match(dev, dr->data, match_data))
 251                         continue;
 252                 return dr;
 253         }
 254 
 255         return NULL;
 256 }
 257 
 258 /**
 259  * devres_find - Find device resource
 260  * @dev: Device to lookup resource from
 261  * @release: Look for resources associated with this release function
 262  * @match: Match function (optional)
 263  * @match_data: Data for the match function
 264  *
 265  * Find the latest devres of @dev which is associated with @release
 266  * and for which @match returns 1.  If @match is NULL, it's considered
 267  * to match all.
 268  *
 269  * RETURNS:
 270  * Pointer to found devres, NULL if not found.
 271  */
 272 void * devres_find(struct device *dev, dr_release_t release,
 273                    dr_match_t match, void *match_data)
 274 {
 275         struct devres *dr;
 276         unsigned long flags;
 277 
 278         spin_lock_irqsave(&dev->devres_lock, flags);
 279         dr = find_dr(dev, release, match, match_data);
 280         spin_unlock_irqrestore(&dev->devres_lock, flags);
 281 
 282         if (dr)
 283                 return dr->data;
 284         return NULL;
 285 }
 286 EXPORT_SYMBOL_GPL(devres_find);
 287 
 288 /**
 289  * devres_get - Find devres, if non-existent, add one atomically
 290  * @dev: Device to lookup or add devres for
 291  * @new_res: Pointer to new initialized devres to add if not found
 292  * @match: Match function (optional)
 293  * @match_data: Data for the match function
 294  *
 295  * Find the latest devres of @dev which has the same release function
 296  * as @new_res and for which @match return 1.  If found, @new_res is
 297  * freed; otherwise, @new_res is added atomically.
 298  *
 299  * RETURNS:
 300  * Pointer to found or added devres.
 301  */
 302 void * devres_get(struct device *dev, void *new_res,
 303                   dr_match_t match, void *match_data)
 304 {
 305         struct devres *new_dr = container_of(new_res, struct devres, data);
 306         struct devres *dr;
 307         unsigned long flags;
 308 
 309         spin_lock_irqsave(&dev->devres_lock, flags);
 310         dr = find_dr(dev, new_dr->node.release, match, match_data);
 311         if (!dr) {
 312                 add_dr(dev, &new_dr->node);
 313                 dr = new_dr;
 314                 new_res = NULL;
 315         }
 316         spin_unlock_irqrestore(&dev->devres_lock, flags);
 317         devres_free(new_res);
 318 
 319         return dr->data;
 320 }
 321 EXPORT_SYMBOL_GPL(devres_get);
 322 
 323 /**
 324  * devres_remove - Find a device resource and remove it
 325  * @dev: Device to find resource from
 326  * @release: Look for resources associated with this release function
 327  * @match: Match function (optional)
 328  * @match_data: Data for the match function
 329  *
 330  * Find the latest devres of @dev associated with @release and for
 331  * which @match returns 1.  If @match is NULL, it's considered to
 332  * match all.  If found, the resource is removed atomically and
 333  * returned.
 334  *
 335  * RETURNS:
 336  * Pointer to removed devres on success, NULL if not found.
 337  */
 338 void * devres_remove(struct device *dev, dr_release_t release,
 339                      dr_match_t match, void *match_data)
 340 {
 341         struct devres *dr;
 342         unsigned long flags;
 343 
 344         spin_lock_irqsave(&dev->devres_lock, flags);
 345         dr = find_dr(dev, release, match, match_data);
 346         if (dr) {
 347                 list_del_init(&dr->node.entry);
 348                 devres_log(dev, &dr->node, "REM");
 349         }
 350         spin_unlock_irqrestore(&dev->devres_lock, flags);
 351 
 352         if (dr)
 353                 return dr->data;
 354         return NULL;
 355 }
 356 EXPORT_SYMBOL_GPL(devres_remove);
 357 
 358 /**
 359  * devres_destroy - Find a device resource and destroy it
 360  * @dev: Device to find resource from
 361  * @release: Look for resources associated with this release function
 362  * @match: Match function (optional)
 363  * @match_data: Data for the match function
 364  *
 365  * Find the latest devres of @dev associated with @release and for
 366  * which @match returns 1.  If @match is NULL, it's considered to
 367  * match all.  If found, the resource is removed atomically and freed.
 368  *
 369  * Note that the release function for the resource will not be called,
 370  * only the devres-allocated data will be freed.  The caller becomes
 371  * responsible for freeing any other data.
 372  *
 373  * RETURNS:
 374  * 0 if devres is found and freed, -ENOENT if not found.
 375  */
 376 int devres_destroy(struct device *dev, dr_release_t release,
 377                    dr_match_t match, void *match_data)
 378 {
 379         void *res;
 380 
 381         res = devres_remove(dev, release, match, match_data);
 382         if (unlikely(!res))
 383                 return -ENOENT;
 384 
 385         devres_free(res);
 386         return 0;
 387 }
 388 EXPORT_SYMBOL_GPL(devres_destroy);
 389 
 390 
 391 /**
 392  * devres_release - Find a device resource and destroy it, calling release
 393  * @dev: Device to find resource from
 394  * @release: Look for resources associated with this release function
 395  * @match: Match function (optional)
 396  * @match_data: Data for the match function
 397  *
 398  * Find the latest devres of @dev associated with @release and for
 399  * which @match returns 1.  If @match is NULL, it's considered to
 400  * match all.  If found, the resource is removed atomically, the
 401  * release function called and the resource freed.
 402  *
 403  * RETURNS:
 404  * 0 if devres is found and freed, -ENOENT if not found.
 405  */
 406 int devres_release(struct device *dev, dr_release_t release,
 407                    dr_match_t match, void *match_data)
 408 {
 409         void *res;
 410 
 411         res = devres_remove(dev, release, match, match_data);
 412         if (unlikely(!res))
 413                 return -ENOENT;
 414 
 415         (*release)(dev, res);
 416         devres_free(res);
 417         return 0;
 418 }
 419 EXPORT_SYMBOL_GPL(devres_release);
 420 
 421 static int remove_nodes(struct device *dev,
 422                         struct list_head *first, struct list_head *end,
 423                         struct list_head *todo)
 424 {
 425         int cnt = 0, nr_groups = 0;
 426         struct list_head *cur;
 427 
 428         /* First pass - move normal devres entries to @todo and clear
 429          * devres_group colors.
 430          */
 431         cur = first;
 432         while (cur != end) {
 433                 struct devres_node *node;
 434                 struct devres_group *grp;
 435 
 436                 node = list_entry(cur, struct devres_node, entry);
 437                 cur = cur->next;
 438 
 439                 grp = node_to_group(node);
 440                 if (grp) {
 441                         /* clear color of group markers in the first pass */
 442                         grp->color = 0;
 443                         nr_groups++;
 444                 } else {
 445                         /* regular devres entry */
 446                         if (&node->entry == first)
 447                                 first = first->next;
 448                         list_move_tail(&node->entry, todo);
 449                         cnt++;
 450                 }
 451         }
 452 
 453         if (!nr_groups)
 454                 return cnt;
 455 
 456         /* Second pass - Scan groups and color them.  A group gets
 457          * color value of two iff the group is wholly contained in
 458          * [cur, end).  That is, for a closed group, both opening and
 459          * closing markers should be in the range, while just the
 460          * opening marker is enough for an open group.
 461          */
 462         cur = first;
 463         while (cur != end) {
 464                 struct devres_node *node;
 465                 struct devres_group *grp;
 466 
 467                 node = list_entry(cur, struct devres_node, entry);
 468                 cur = cur->next;
 469 
 470                 grp = node_to_group(node);
 471                 BUG_ON(!grp || list_empty(&grp->node[0].entry));
 472 
 473                 grp->color++;
 474                 if (list_empty(&grp->node[1].entry))
 475                         grp->color++;
 476 
 477                 BUG_ON(grp->color <= 0 || grp->color > 2);
 478                 if (grp->color == 2) {
 479                         /* No need to update cur or end.  The removed
 480                          * nodes are always before both.
 481                          */
 482                         list_move_tail(&grp->node[0].entry, todo);
 483                         list_del_init(&grp->node[1].entry);
 484                 }
 485         }
 486 
 487         return cnt;
 488 }
 489 
 490 static int release_nodes(struct device *dev, struct list_head *first,
 491                          struct list_head *end, unsigned long flags)
 492         __releases(&dev->devres_lock)
 493 {
 494         LIST_HEAD(todo);
 495         int cnt;
 496         struct devres *dr, *tmp;
 497 
 498         cnt = remove_nodes(dev, first, end, &todo);
 499 
 500         spin_unlock_irqrestore(&dev->devres_lock, flags);
 501 
 502         /* Release.  Note that both devres and devres_group are
 503          * handled as devres in the following loop.  This is safe.
 504          */
 505         list_for_each_entry_safe_reverse(dr, tmp, &todo, node.entry) {
 506                 devres_log(dev, &dr->node, "REL");
 507                 dr->node.release(dev, dr->data);
 508                 kfree(dr);
 509         }
 510 
 511         return cnt;
 512 }
 513 
 514 /**
 515  * devres_release_all - Release all managed resources
 516  * @dev: Device to release resources for
 517  *
 518  * Release all resources associated with @dev.  This function is
 519  * called on driver detach.
 520  */
 521 int devres_release_all(struct device *dev)
 522 {
 523         unsigned long flags;
 524 
 525         /* Looks like an uninitialized device structure */
 526         if (WARN_ON(dev->devres_head.next == NULL))
 527                 return -ENODEV;
 528         spin_lock_irqsave(&dev->devres_lock, flags);
 529         return release_nodes(dev, dev->devres_head.next, &dev->devres_head,
 530                              flags);
 531 }
 532 
 533 /**
 534  * devres_open_group - Open a new devres group
 535  * @dev: Device to open devres group for
 536  * @id: Separator ID
 537  * @gfp: Allocation flags
 538  *
 539  * Open a new devres group for @dev with @id.  For @id, using a
 540  * pointer to an object which won't be used for another group is
 541  * recommended.  If @id is NULL, address-wise unique ID is created.
 542  *
 543  * RETURNS:
 544  * ID of the new group, NULL on failure.
 545  */
 546 void * devres_open_group(struct device *dev, void *id, gfp_t gfp)
 547 {
 548         struct devres_group *grp;
 549         unsigned long flags;
 550 
 551         grp = kmalloc(sizeof(*grp), gfp);
 552         if (unlikely(!grp))
 553                 return NULL;
 554 
 555         grp->node[0].release = &group_open_release;
 556         grp->node[1].release = &group_close_release;
 557         INIT_LIST_HEAD(&grp->node[0].entry);
 558         INIT_LIST_HEAD(&grp->node[1].entry);
 559         set_node_dbginfo(&grp->node[0], "grp<", 0);
 560         set_node_dbginfo(&grp->node[1], "grp>", 0);
 561         grp->id = grp;
 562         if (id)
 563                 grp->id = id;
 564 
 565         spin_lock_irqsave(&dev->devres_lock, flags);
 566         add_dr(dev, &grp->node[0]);
 567         spin_unlock_irqrestore(&dev->devres_lock, flags);
 568         return grp->id;
 569 }
 570 EXPORT_SYMBOL_GPL(devres_open_group);
 571 
 572 /* Find devres group with ID @id.  If @id is NULL, look for the latest. */
 573 static struct devres_group * find_group(struct device *dev, void *id)
 574 {
 575         struct devres_node *node;
 576 
 577         list_for_each_entry_reverse(node, &dev->devres_head, entry) {
 578                 struct devres_group *grp;
 579 
 580                 if (node->release != &group_open_release)
 581                         continue;
 582 
 583                 grp = container_of(node, struct devres_group, node[0]);
 584 
 585                 if (id) {
 586                         if (grp->id == id)
 587                                 return grp;
 588                 } else if (list_empty(&grp->node[1].entry))
 589                         return grp;
 590         }
 591 
 592         return NULL;
 593 }
 594 
 595 /**
 596  * devres_close_group - Close a devres group
 597  * @dev: Device to close devres group for
 598  * @id: ID of target group, can be NULL
 599  *
 600  * Close the group identified by @id.  If @id is NULL, the latest open
 601  * group is selected.
 602  */
 603 void devres_close_group(struct device *dev, void *id)
 604 {
 605         struct devres_group *grp;
 606         unsigned long flags;
 607 
 608         spin_lock_irqsave(&dev->devres_lock, flags);
 609 
 610         grp = find_group(dev, id);
 611         if (grp)
 612                 add_dr(dev, &grp->node[1]);
 613         else
 614                 WARN_ON(1);
 615 
 616         spin_unlock_irqrestore(&dev->devres_lock, flags);
 617 }
 618 EXPORT_SYMBOL_GPL(devres_close_group);
 619 
 620 /**
 621  * devres_remove_group - Remove a devres group
 622  * @dev: Device to remove group for
 623  * @id: ID of target group, can be NULL
 624  *
 625  * Remove the group identified by @id.  If @id is NULL, the latest
 626  * open group is selected.  Note that removing a group doesn't affect
 627  * any other resources.
 628  */
 629 void devres_remove_group(struct device *dev, void *id)
 630 {
 631         struct devres_group *grp;
 632         unsigned long flags;
 633 
 634         spin_lock_irqsave(&dev->devres_lock, flags);
 635 
 636         grp = find_group(dev, id);
 637         if (grp) {
 638                 list_del_init(&grp->node[0].entry);
 639                 list_del_init(&grp->node[1].entry);
 640                 devres_log(dev, &grp->node[0], "REM");
 641         } else
 642                 WARN_ON(1);
 643 
 644         spin_unlock_irqrestore(&dev->devres_lock, flags);
 645 
 646         kfree(grp);
 647 }
 648 EXPORT_SYMBOL_GPL(devres_remove_group);
 649 
 650 /**
 651  * devres_release_group - Release resources in a devres group
 652  * @dev: Device to release group for
 653  * @id: ID of target group, can be NULL
 654  *
 655  * Release all resources in the group identified by @id.  If @id is
 656  * NULL, the latest open group is selected.  The selected group and
 657  * groups properly nested inside the selected group are removed.
 658  *
 659  * RETURNS:
 660  * The number of released non-group resources.
 661  */
 662 int devres_release_group(struct device *dev, void *id)
 663 {
 664         struct devres_group *grp;
 665         unsigned long flags;
 666         int cnt = 0;
 667 
 668         spin_lock_irqsave(&dev->devres_lock, flags);
 669 
 670         grp = find_group(dev, id);
 671         if (grp) {
 672                 struct list_head *first = &grp->node[0].entry;
 673                 struct list_head *end = &dev->devres_head;
 674 
 675                 if (!list_empty(&grp->node[1].entry))
 676                         end = grp->node[1].entry.next;
 677 
 678                 cnt = release_nodes(dev, first, end, flags);
 679         } else {
 680                 WARN_ON(1);
 681                 spin_unlock_irqrestore(&dev->devres_lock, flags);
 682         }
 683 
 684         return cnt;
 685 }
 686 EXPORT_SYMBOL_GPL(devres_release_group);
 687 
 688 /*
 689  * Custom devres actions allow inserting a simple function call
 690  * into the teadown sequence.
 691  */
 692 
 693 struct action_devres {
 694         void *data;
 695         void (*action)(void *);
 696 };
 697 
 698 static int devm_action_match(struct device *dev, void *res, void *p)
 699 {
 700         struct action_devres *devres = res;
 701         struct action_devres *target = p;
 702 
 703         return devres->action == target->action &&
 704                devres->data == target->data;
 705 }
 706 
 707 static void devm_action_release(struct device *dev, void *res)
 708 {
 709         struct action_devres *devres = res;
 710 
 711         devres->action(devres->data);
 712 }
 713 
 714 /**
 715  * devm_add_action() - add a custom action to list of managed resources
 716  * @dev: Device that owns the action
 717  * @action: Function that should be called
 718  * @data: Pointer to data passed to @action implementation
 719  *
 720  * This adds a custom action to the list of managed resources so that
 721  * it gets executed as part of standard resource unwinding.
 722  */
 723 int devm_add_action(struct device *dev, void (*action)(void *), void *data)
 724 {
 725         struct action_devres *devres;
 726 
 727         devres = devres_alloc(devm_action_release,
 728                               sizeof(struct action_devres), GFP_KERNEL);
 729         if (!devres)
 730                 return -ENOMEM;
 731 
 732         devres->data = data;
 733         devres->action = action;
 734 
 735         devres_add(dev, devres);
 736         return 0;
 737 }
 738 EXPORT_SYMBOL_GPL(devm_add_action);
 739 
 740 /**
 741  * devm_remove_action() - removes previously added custom action
 742  * @dev: Device that owns the action
 743  * @action: Function implementing the action
 744  * @data: Pointer to data passed to @action implementation
 745  *
 746  * Removes instance of @action previously added by devm_add_action().
 747  * Both action and data should match one of the existing entries.
 748  */
 749 void devm_remove_action(struct device *dev, void (*action)(void *), void *data)
 750 {
 751         struct action_devres devres = {
 752                 .data = data,
 753                 .action = action,
 754         };
 755 
 756         WARN_ON(devres_destroy(dev, devm_action_release, devm_action_match,
 757                                &devres));
 758 }
 759 EXPORT_SYMBOL_GPL(devm_remove_action);
 760 
 761 /**
 762  * devm_release_action() - release previously added custom action
 763  * @dev: Device that owns the action
 764  * @action: Function implementing the action
 765  * @data: Pointer to data passed to @action implementation
 766  *
 767  * Releases and removes instance of @action previously added by
 768  * devm_add_action().  Both action and data should match one of the
 769  * existing entries.
 770  */
 771 void devm_release_action(struct device *dev, void (*action)(void *), void *data)
 772 {
 773         struct action_devres devres = {
 774                 .data = data,
 775                 .action = action,
 776         };
 777 
 778         WARN_ON(devres_release(dev, devm_action_release, devm_action_match,
 779                                &devres));
 780 
 781 }
 782 EXPORT_SYMBOL_GPL(devm_release_action);
 783 
 784 /*
 785  * Managed kmalloc/kfree
 786  */
 787 static void devm_kmalloc_release(struct device *dev, void *res)
 788 {
 789         /* noop */
 790 }
 791 
 792 static int devm_kmalloc_match(struct device *dev, void *res, void *data)
 793 {
 794         return res == data;
 795 }
 796 
 797 /**
 798  * devm_kmalloc - Resource-managed kmalloc
 799  * @dev: Device to allocate memory for
 800  * @size: Allocation size
 801  * @gfp: Allocation gfp flags
 802  *
 803  * Managed kmalloc.  Memory allocated with this function is
 804  * automatically freed on driver detach.  Like all other devres
 805  * resources, guaranteed alignment is unsigned long long.
 806  *
 807  * RETURNS:
 808  * Pointer to allocated memory on success, NULL on failure.
 809  */
 810 void * devm_kmalloc(struct device *dev, size_t size, gfp_t gfp)
 811 {
 812         struct devres *dr;
 813 
 814         /* use raw alloc_dr for kmalloc caller tracing */
 815         dr = alloc_dr(devm_kmalloc_release, size, gfp, dev_to_node(dev));
 816         if (unlikely(!dr))
 817                 return NULL;
 818 
 819         /*
 820          * This is named devm_kzalloc_release for historical reasons
 821          * The initial implementation did not support kmalloc, only kzalloc
 822          */
 823         set_node_dbginfo(&dr->node, "devm_kzalloc_release", size);
 824         devres_add(dev, dr->data);
 825         return dr->data;
 826 }
 827 EXPORT_SYMBOL_GPL(devm_kmalloc);
 828 
 829 /**
 830  * devm_kstrdup - Allocate resource managed space and
 831  *                copy an existing string into that.
 832  * @dev: Device to allocate memory for
 833  * @s: the string to duplicate
 834  * @gfp: the GFP mask used in the devm_kmalloc() call when
 835  *       allocating memory
 836  * RETURNS:
 837  * Pointer to allocated string on success, NULL on failure.
 838  */
 839 char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp)
 840 {
 841         size_t size;
 842         char *buf;
 843 
 844         if (!s)
 845                 return NULL;
 846 
 847         size = strlen(s) + 1;
 848         buf = devm_kmalloc(dev, size, gfp);
 849         if (buf)
 850                 memcpy(buf, s, size);
 851         return buf;
 852 }
 853 EXPORT_SYMBOL_GPL(devm_kstrdup);
 854 
 855 /**
 856  * devm_kstrdup_const - resource managed conditional string duplication
 857  * @dev: device for which to duplicate the string
 858  * @s: the string to duplicate
 859  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
 860  *
 861  * Strings allocated by devm_kstrdup_const will be automatically freed when
 862  * the associated device is detached.
 863  *
 864  * RETURNS:
 865  * Source string if it is in .rodata section otherwise it falls back to
 866  * devm_kstrdup.
 867  */
 868 const char *devm_kstrdup_const(struct device *dev, const char *s, gfp_t gfp)
 869 {
 870         if (is_kernel_rodata((unsigned long)s))
 871                 return s;
 872 
 873         return devm_kstrdup(dev, s, gfp);
 874 }
 875 EXPORT_SYMBOL_GPL(devm_kstrdup_const);
 876 
 877 /**
 878  * devm_kvasprintf - Allocate resource managed space and format a string
 879  *                   into that.
 880  * @dev: Device to allocate memory for
 881  * @gfp: the GFP mask used in the devm_kmalloc() call when
 882  *       allocating memory
 883  * @fmt: The printf()-style format string
 884  * @ap: Arguments for the format string
 885  * RETURNS:
 886  * Pointer to allocated string on success, NULL on failure.
 887  */
 888 char *devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt,
 889                       va_list ap)
 890 {
 891         unsigned int len;
 892         char *p;
 893         va_list aq;
 894 
 895         va_copy(aq, ap);
 896         len = vsnprintf(NULL, 0, fmt, aq);
 897         va_end(aq);
 898 
 899         p = devm_kmalloc(dev, len+1, gfp);
 900         if (!p)
 901                 return NULL;
 902 
 903         vsnprintf(p, len+1, fmt, ap);
 904 
 905         return p;
 906 }
 907 EXPORT_SYMBOL(devm_kvasprintf);
 908 
 909 /**
 910  * devm_kasprintf - Allocate resource managed space and format a string
 911  *                  into that.
 912  * @dev: Device to allocate memory for
 913  * @gfp: the GFP mask used in the devm_kmalloc() call when
 914  *       allocating memory
 915  * @fmt: The printf()-style format string
 916  * @...: Arguments for the format string
 917  * RETURNS:
 918  * Pointer to allocated string on success, NULL on failure.
 919  */
 920 char *devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
 921 {
 922         va_list ap;
 923         char *p;
 924 
 925         va_start(ap, fmt);
 926         p = devm_kvasprintf(dev, gfp, fmt, ap);
 927         va_end(ap);
 928 
 929         return p;
 930 }
 931 EXPORT_SYMBOL_GPL(devm_kasprintf);
 932 
 933 /**
 934  * devm_kfree - Resource-managed kfree
 935  * @dev: Device this memory belongs to
 936  * @p: Memory to free
 937  *
 938  * Free memory allocated with devm_kmalloc().
 939  */
 940 void devm_kfree(struct device *dev, const void *p)
 941 {
 942         int rc;
 943 
 944         /*
 945          * Special case: pointer to a string in .rodata returned by
 946          * devm_kstrdup_const().
 947          */
 948         if (unlikely(is_kernel_rodata((unsigned long)p)))
 949                 return;
 950 
 951         rc = devres_destroy(dev, devm_kmalloc_release,
 952                             devm_kmalloc_match, (void *)p);
 953         WARN_ON(rc);
 954 }
 955 EXPORT_SYMBOL_GPL(devm_kfree);
 956 
 957 /**
 958  * devm_kmemdup - Resource-managed kmemdup
 959  * @dev: Device this memory belongs to
 960  * @src: Memory region to duplicate
 961  * @len: Memory region length
 962  * @gfp: GFP mask to use
 963  *
 964  * Duplicate region of a memory using resource managed kmalloc
 965  */
 966 void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp)
 967 {
 968         void *p;
 969 
 970         p = devm_kmalloc(dev, len, gfp);
 971         if (p)
 972                 memcpy(p, src, len);
 973 
 974         return p;
 975 }
 976 EXPORT_SYMBOL_GPL(devm_kmemdup);
 977 
 978 struct pages_devres {
 979         unsigned long addr;
 980         unsigned int order;
 981 };
 982 
 983 static int devm_pages_match(struct device *dev, void *res, void *p)
 984 {
 985         struct pages_devres *devres = res;
 986         struct pages_devres *target = p;
 987 
 988         return devres->addr == target->addr;
 989 }
 990 
 991 static void devm_pages_release(struct device *dev, void *res)
 992 {
 993         struct pages_devres *devres = res;
 994 
 995         free_pages(devres->addr, devres->order);
 996 }
 997 
 998 /**
 999  * devm_get_free_pages - Resource-managed __get_free_pages
1000  * @dev: Device to allocate memory for
1001  * @gfp_mask: Allocation gfp flags
1002  * @order: Allocation size is (1 << order) pages
1003  *
1004  * Managed get_free_pages.  Memory allocated with this function is
1005  * automatically freed on driver detach.
1006  *
1007  * RETURNS:
1008  * Address of allocated memory on success, 0 on failure.
1009  */
1010 
1011 unsigned long devm_get_free_pages(struct device *dev,
1012                                   gfp_t gfp_mask, unsigned int order)
1013 {
1014         struct pages_devres *devres;
1015         unsigned long addr;
1016 
1017         addr = __get_free_pages(gfp_mask, order);
1018 
1019         if (unlikely(!addr))
1020                 return 0;
1021 
1022         devres = devres_alloc(devm_pages_release,
1023                               sizeof(struct pages_devres), GFP_KERNEL);
1024         if (unlikely(!devres)) {
1025                 free_pages(addr, order);
1026                 return 0;
1027         }
1028 
1029         devres->addr = addr;
1030         devres->order = order;
1031 
1032         devres_add(dev, devres);
1033         return addr;
1034 }
1035 EXPORT_SYMBOL_GPL(devm_get_free_pages);
1036 
1037 /**
1038  * devm_free_pages - Resource-managed free_pages
1039  * @dev: Device this memory belongs to
1040  * @addr: Memory to free
1041  *
1042  * Free memory allocated with devm_get_free_pages(). Unlike free_pages,
1043  * there is no need to supply the @order.
1044  */
1045 void devm_free_pages(struct device *dev, unsigned long addr)
1046 {
1047         struct pages_devres devres = { .addr = addr };
1048 
1049         WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match,
1050                                &devres));
1051 }
1052 EXPORT_SYMBOL_GPL(devm_free_pages);
1053 
1054 static void devm_percpu_release(struct device *dev, void *pdata)
1055 {
1056         void __percpu *p;
1057 
1058         p = *(void __percpu **)pdata;
1059         free_percpu(p);
1060 }
1061 
1062 static int devm_percpu_match(struct device *dev, void *data, void *p)
1063 {
1064         struct devres *devr = container_of(data, struct devres, data);
1065 
1066         return *(void **)devr->data == p;
1067 }
1068 
1069 /**
1070  * __devm_alloc_percpu - Resource-managed alloc_percpu
1071  * @dev: Device to allocate per-cpu memory for
1072  * @size: Size of per-cpu memory to allocate
1073  * @align: Alignment of per-cpu memory to allocate
1074  *
1075  * Managed alloc_percpu. Per-cpu memory allocated with this function is
1076  * automatically freed on driver detach.
1077  *
1078  * RETURNS:
1079  * Pointer to allocated memory on success, NULL on failure.
1080  */
1081 void __percpu *__devm_alloc_percpu(struct device *dev, size_t size,
1082                 size_t align)
1083 {
1084         void *p;
1085         void __percpu *pcpu;
1086 
1087         pcpu = __alloc_percpu(size, align);
1088         if (!pcpu)
1089                 return NULL;
1090 
1091         p = devres_alloc(devm_percpu_release, sizeof(void *), GFP_KERNEL);
1092         if (!p) {
1093                 free_percpu(pcpu);
1094                 return NULL;
1095         }
1096 
1097         *(void __percpu **)p = pcpu;
1098 
1099         devres_add(dev, p);
1100 
1101         return pcpu;
1102 }
1103 EXPORT_SYMBOL_GPL(__devm_alloc_percpu);
1104 
1105 /**
1106  * devm_free_percpu - Resource-managed free_percpu
1107  * @dev: Device this memory belongs to
1108  * @pdata: Per-cpu memory to free
1109  *
1110  * Free memory allocated with devm_alloc_percpu().
1111  */
1112 void devm_free_percpu(struct device *dev, void __percpu *pdata)
1113 {
1114         WARN_ON(devres_destroy(dev, devm_percpu_release, devm_percpu_match,
1115                                (void *)pdata));
1116 }
1117 EXPORT_SYMBOL_GPL(devm_free_percpu);
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root/drivers/base/devres.c

DEFINITIONS
