Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001 Momchil Velikov | |
3 | * Portions Copyright (C) 2001 Christoph Hellwig | |
7cf9c2c7 | 4 | * Copyright (C) 2006 Nick Piggin |
78c1d784 | 5 | * Copyright (C) 2012 Konstantin Khlebnikov |
1da177e4 LT |
6 | * |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License as | |
9 | * published by the Free Software Foundation; either version 2, or (at | |
10 | * your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, but | |
13 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
15 | * General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | #ifndef _LINUX_RADIX_TREE_H | |
22 | #define _LINUX_RADIX_TREE_H | |
23 | ||
f67c07f0 | 24 | #include <linux/bitops.h> |
1da177e4 LT |
25 | #include <linux/preempt.h> |
26 | #include <linux/types.h> | |
187f1882 | 27 | #include <linux/bug.h> |
7cf9c2c7 NP |
28 | #include <linux/kernel.h> |
29 | #include <linux/rcupdate.h> | |
30 | ||
31 | /* | |
30ff46cc MW |
32 | * Entries in the radix tree have the low bit set if they refer to a |
33 | * radix_tree_node. If the low bit is clear then the entry is user data. | |
7cf9c2c7 | 34 | * |
30ff46cc MW |
35 | * We also use the low bit to indicate that the slot will be freed in the |
36 | * next RCU idle period, and users need to re-walk the tree to find the | |
37 | * new slot for the index that they were looking for. See the comment in | |
38 | * radix_tree_shrink() for details. | |
7cf9c2c7 | 39 | */ |
30ff46cc MW |
40 | #define RADIX_TREE_INTERNAL_NODE 1 |
41 | ||
6328650b HD |
42 | /* |
43 | * A common use of the radix tree is to store pointers to struct pages; | |
44 | * but shmem/tmpfs needs also to store swap entries in the same tree: | |
45 | * those are marked as exceptional entries to distinguish them. | |
46 | * EXCEPTIONAL_ENTRY tests the bit, EXCEPTIONAL_SHIFT shifts content past it. | |
47 | */ | |
48 | #define RADIX_TREE_EXCEPTIONAL_ENTRY 2 | |
49 | #define RADIX_TREE_EXCEPTIONAL_SHIFT 2 | |
7cf9c2c7 | 50 | |
b194d16c | 51 | static inline int radix_tree_is_internal_node(void *ptr) |
7cf9c2c7 | 52 | { |
30ff46cc | 53 | return (int)((unsigned long)ptr & RADIX_TREE_INTERNAL_NODE); |
7cf9c2c7 NP |
54 | } |
55 | ||
56 | /*** radix-tree API starts here ***/ | |
1da177e4 | 57 | |
f446daae | 58 | #define RADIX_TREE_MAX_TAGS 3 |
612d6c19 | 59 | |
97d778b2 | 60 | #ifndef RADIX_TREE_MAP_SHIFT |
139e5616 | 61 | #define RADIX_TREE_MAP_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) |
139e5616 JW |
62 | #endif |
63 | ||
64 | #define RADIX_TREE_MAP_SIZE (1UL << RADIX_TREE_MAP_SHIFT) | |
65 | #define RADIX_TREE_MAP_MASK (RADIX_TREE_MAP_SIZE-1) | |
66 | ||
67 | #define RADIX_TREE_TAG_LONGS \ | |
68 | ((RADIX_TREE_MAP_SIZE + BITS_PER_LONG - 1) / BITS_PER_LONG) | |
69 | ||
449dd698 JW |
70 | #define RADIX_TREE_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(unsigned long)) |
71 | #define RADIX_TREE_MAX_PATH (DIV_ROUND_UP(RADIX_TREE_INDEX_BITS, \ | |
72 | RADIX_TREE_MAP_SHIFT)) | |
73 | ||
449dd698 JW |
74 | /* Internally used bits of node->count */ |
75 | #define RADIX_TREE_COUNT_SHIFT (RADIX_TREE_MAP_SHIFT + 1) | |
76 | #define RADIX_TREE_COUNT_MASK ((1UL << RADIX_TREE_COUNT_SHIFT) - 1) | |
77 | ||
139e5616 | 78 | struct radix_tree_node { |
c12e51b0 | 79 | unsigned char shift; /* Bits remaining in each slot */ |
0c7fa0a8 | 80 | unsigned char offset; /* Slot offset in parent */ |
139e5616 JW |
81 | unsigned int count; |
82 | union { | |
449dd698 JW |
83 | struct { |
84 | /* Used when ascending tree */ | |
85 | struct radix_tree_node *parent; | |
86 | /* For tree user */ | |
87 | void *private_data; | |
88 | }; | |
89 | /* Used when freeing node */ | |
90 | struct rcu_head rcu_head; | |
139e5616 | 91 | }; |
449dd698 JW |
92 | /* For tree user */ |
93 | struct list_head private_list; | |
139e5616 JW |
94 | void __rcu *slots[RADIX_TREE_MAP_SIZE]; |
95 | unsigned long tags[RADIX_TREE_MAX_TAGS][RADIX_TREE_TAG_LONGS]; | |
96 | }; | |
97 | ||
612d6c19 | 98 | /* root tags are stored in gfp_mask, shifted by __GFP_BITS_SHIFT */ |
1da177e4 | 99 | struct radix_tree_root { |
fd4f2df2 | 100 | gfp_t gfp_mask; |
a1115570 | 101 | struct radix_tree_node __rcu *rnode; |
1da177e4 LT |
102 | }; |
103 | ||
104 | #define RADIX_TREE_INIT(mask) { \ | |
1da177e4 LT |
105 | .gfp_mask = (mask), \ |
106 | .rnode = NULL, \ | |
107 | } | |
108 | ||
109 | #define RADIX_TREE(name, mask) \ | |
110 | struct radix_tree_root name = RADIX_TREE_INIT(mask) | |
111 | ||
112 | #define INIT_RADIX_TREE(root, mask) \ | |
113 | do { \ | |
1da177e4 LT |
114 | (root)->gfp_mask = (mask); \ |
115 | (root)->rnode = NULL; \ | |
116 | } while (0) | |
117 | ||
e9256efc MW |
118 | static inline bool radix_tree_empty(struct radix_tree_root *root) |
119 | { | |
120 | return root->rnode == NULL; | |
121 | } | |
122 | ||
7cf9c2c7 NP |
123 | /** |
124 | * Radix-tree synchronization | |
125 | * | |
126 | * The radix-tree API requires that users provide all synchronisation (with | |
127 | * specific exceptions, noted below). | |
128 | * | |
129 | * Synchronization of access to the data items being stored in the tree, and | |
130 | * management of their lifetimes must be completely managed by API users. | |
131 | * | |
132 | * For API usage, in general, | |
59c51591 | 133 | * - any function _modifying_ the tree or tags (inserting or deleting |
eb8dc5e7 | 134 | * items, setting or clearing tags) must exclude other modifications, and |
7cf9c2c7 | 135 | * exclude any functions reading the tree. |
59c51591 | 136 | * - any function _reading_ the tree or tags (looking up items or tags, |
7cf9c2c7 NP |
137 | * gang lookups) must exclude modifications to the tree, but may occur |
138 | * concurrently with other readers. | |
139 | * | |
140 | * The notable exceptions to this rule are the following functions: | |
139e5616 | 141 | * __radix_tree_lookup |
7cf9c2c7 | 142 | * radix_tree_lookup |
47feff2c | 143 | * radix_tree_lookup_slot |
7cf9c2c7 NP |
144 | * radix_tree_tag_get |
145 | * radix_tree_gang_lookup | |
47feff2c | 146 | * radix_tree_gang_lookup_slot |
7cf9c2c7 | 147 | * radix_tree_gang_lookup_tag |
47feff2c | 148 | * radix_tree_gang_lookup_tag_slot |
7cf9c2c7 NP |
149 | * radix_tree_tagged |
150 | * | |
243c2137 | 151 | * The first 8 functions are able to be called locklessly, using RCU. The |
7cf9c2c7 NP |
152 | * caller must ensure calls to these functions are made within rcu_read_lock() |
153 | * regions. Other readers (lock-free or otherwise) and modifications may be | |
154 | * running concurrently. | |
155 | * | |
156 | * It is still required that the caller manage the synchronization and lifetimes | |
157 | * of the items. So if RCU lock-free lookups are used, typically this would mean | |
158 | * that the items have their own locks, or are amenable to lock-free access; and | |
159 | * that the items are freed by RCU (or only freed after having been deleted from | |
160 | * the radix tree *and* a synchronize_rcu() grace period). | |
161 | * | |
162 | * (Note, rcu_assign_pointer and rcu_dereference are not needed to control | |
163 | * access to data items when inserting into or looking up from the radix tree) | |
164 | * | |
ce82653d DH |
165 | * Note that the value returned by radix_tree_tag_get() may not be relied upon |
166 | * if only the RCU read lock is held. Functions to set/clear tags and to | |
167 | * delete nodes running concurrently with it may affect its result such that | |
168 | * two consecutive reads in the same locked section may return different | |
169 | * values. If reliability is required, modification functions must also be | |
170 | * excluded from concurrency. | |
171 | * | |
7cf9c2c7 NP |
172 | * radix_tree_tagged is able to be called without locking or RCU. |
173 | */ | |
174 | ||
175 | /** | |
176 | * radix_tree_deref_slot - dereference a slot | |
177 | * @pslot: pointer to slot, returned by radix_tree_lookup_slot | |
178 | * Returns: item that was stored in that slot with any direct pointer flag | |
179 | * removed. | |
180 | * | |
181 | * For use with radix_tree_lookup_slot(). Caller must hold tree at least read | |
27d20fdd NP |
182 | * locked across slot lookup and dereference. Not required if write lock is |
183 | * held (ie. items cannot be concurrently inserted). | |
184 | * | |
185 | * radix_tree_deref_retry must be used to confirm validity of the pointer if | |
186 | * only the read lock is held. | |
7cf9c2c7 NP |
187 | */ |
188 | static inline void *radix_tree_deref_slot(void **pslot) | |
189 | { | |
27d20fdd | 190 | return rcu_dereference(*pslot); |
7cf9c2c7 | 191 | } |
27d20fdd | 192 | |
29c1f677 MG |
193 | /** |
194 | * radix_tree_deref_slot_protected - dereference a slot without RCU lock but with tree lock held | |
195 | * @pslot: pointer to slot, returned by radix_tree_lookup_slot | |
196 | * Returns: item that was stored in that slot with any direct pointer flag | |
197 | * removed. | |
198 | * | |
199 | * Similar to radix_tree_deref_slot but only used during migration when a pages | |
200 | * mapping is being moved. The caller does not hold the RCU read lock but it | |
201 | * must hold the tree lock to prevent parallel updates. | |
202 | */ | |
203 | static inline void *radix_tree_deref_slot_protected(void **pslot, | |
204 | spinlock_t *treelock) | |
205 | { | |
206 | return rcu_dereference_protected(*pslot, lockdep_is_held(treelock)); | |
207 | } | |
208 | ||
27d20fdd NP |
209 | /** |
210 | * radix_tree_deref_retry - check radix_tree_deref_slot | |
211 | * @arg: pointer returned by radix_tree_deref_slot | |
212 | * Returns: 0 if retry is not required, otherwise retry is required | |
213 | * | |
214 | * radix_tree_deref_retry must be used with radix_tree_deref_slot. | |
215 | */ | |
216 | static inline int radix_tree_deref_retry(void *arg) | |
217 | { | |
b194d16c | 218 | return unlikely(radix_tree_is_internal_node(arg)); |
27d20fdd NP |
219 | } |
220 | ||
6328650b HD |
221 | /** |
222 | * radix_tree_exceptional_entry - radix_tree_deref_slot gave exceptional entry? | |
223 | * @arg: value returned by radix_tree_deref_slot | |
224 | * Returns: 0 if well-aligned pointer, non-0 if exceptional entry. | |
225 | */ | |
226 | static inline int radix_tree_exceptional_entry(void *arg) | |
227 | { | |
228 | /* Not unlikely because radix_tree_exception often tested first */ | |
229 | return (unsigned long)arg & RADIX_TREE_EXCEPTIONAL_ENTRY; | |
230 | } | |
231 | ||
232 | /** | |
233 | * radix_tree_exception - radix_tree_deref_slot returned either exception? | |
234 | * @arg: value returned by radix_tree_deref_slot | |
235 | * Returns: 0 if well-aligned pointer, non-0 if either kind of exception. | |
236 | */ | |
237 | static inline int radix_tree_exception(void *arg) | |
238 | { | |
239 | return unlikely((unsigned long)arg & | |
30ff46cc | 240 | (RADIX_TREE_INTERNAL_NODE | RADIX_TREE_EXCEPTIONAL_ENTRY)); |
6328650b HD |
241 | } |
242 | ||
7cf9c2c7 NP |
243 | /** |
244 | * radix_tree_replace_slot - replace item in a slot | |
245 | * @pslot: pointer to slot, returned by radix_tree_lookup_slot | |
246 | * @item: new item to store in the slot. | |
247 | * | |
248 | * For use with radix_tree_lookup_slot(). Caller must hold tree write locked | |
249 | * across slot lookup and replacement. | |
250 | */ | |
251 | static inline void radix_tree_replace_slot(void **pslot, void *item) | |
252 | { | |
b194d16c | 253 | BUG_ON(radix_tree_is_internal_node(item)); |
c0bc9875 | 254 | rcu_assign_pointer(*pslot, item); |
7cf9c2c7 NP |
255 | } |
256 | ||
139e5616 | 257 | int __radix_tree_create(struct radix_tree_root *root, unsigned long index, |
e6145236 MW |
258 | unsigned order, struct radix_tree_node **nodep, |
259 | void ***slotp); | |
260 | int __radix_tree_insert(struct radix_tree_root *, unsigned long index, | |
261 | unsigned order, void *); | |
262 | static inline int radix_tree_insert(struct radix_tree_root *root, | |
263 | unsigned long index, void *entry) | |
264 | { | |
265 | return __radix_tree_insert(root, index, 0, entry); | |
266 | } | |
139e5616 JW |
267 | void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index, |
268 | struct radix_tree_node **nodep, void ***slotp); | |
1da177e4 | 269 | void *radix_tree_lookup(struct radix_tree_root *, unsigned long); |
a4331366 | 270 | void **radix_tree_lookup_slot(struct radix_tree_root *, unsigned long); |
449dd698 | 271 | bool __radix_tree_delete_node(struct radix_tree_root *root, |
139e5616 | 272 | struct radix_tree_node *node); |
53c59f26 | 273 | void *radix_tree_delete_item(struct radix_tree_root *, unsigned long, void *); |
1da177e4 | 274 | void *radix_tree_delete(struct radix_tree_root *, unsigned long); |
d604c324 MW |
275 | struct radix_tree_node *radix_tree_replace_clear_tags( |
276 | struct radix_tree_root *root, | |
277 | unsigned long index, void *entry); | |
278 | unsigned int radix_tree_gang_lookup(struct radix_tree_root *root, | |
279 | void **results, unsigned long first_index, | |
280 | unsigned int max_items); | |
6328650b HD |
281 | unsigned int radix_tree_gang_lookup_slot(struct radix_tree_root *root, |
282 | void ***results, unsigned long *indices, | |
47feff2c | 283 | unsigned long first_index, unsigned int max_items); |
dd0fc66f | 284 | int radix_tree_preload(gfp_t gfp_mask); |
5e4c0d97 | 285 | int radix_tree_maybe_preload(gfp_t gfp_mask); |
1da177e4 LT |
286 | void radix_tree_init(void); |
287 | void *radix_tree_tag_set(struct radix_tree_root *root, | |
daff89f3 | 288 | unsigned long index, unsigned int tag); |
1da177e4 | 289 | void *radix_tree_tag_clear(struct radix_tree_root *root, |
daff89f3 | 290 | unsigned long index, unsigned int tag); |
1da177e4 | 291 | int radix_tree_tag_get(struct radix_tree_root *root, |
daff89f3 | 292 | unsigned long index, unsigned int tag); |
1da177e4 LT |
293 | unsigned int |
294 | radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, | |
daff89f3 JC |
295 | unsigned long first_index, unsigned int max_items, |
296 | unsigned int tag); | |
47feff2c NP |
297 | unsigned int |
298 | radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results, | |
299 | unsigned long first_index, unsigned int max_items, | |
300 | unsigned int tag); | |
ebf8aa44 JK |
301 | unsigned long radix_tree_range_tag_if_tagged(struct radix_tree_root *root, |
302 | unsigned long *first_indexp, unsigned long last_index, | |
303 | unsigned long nr_to_tag, | |
304 | unsigned int fromtag, unsigned int totag); | |
daff89f3 | 305 | int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag); |
e504f3fd | 306 | unsigned long radix_tree_locate_item(struct radix_tree_root *root, void *item); |
1da177e4 LT |
307 | |
308 | static inline void radix_tree_preload_end(void) | |
309 | { | |
310 | preempt_enable(); | |
311 | } | |
312 | ||
78c1d784 KK |
313 | /** |
314 | * struct radix_tree_iter - radix tree iterator state | |
315 | * | |
316 | * @index: index of current slot | |
21ef5339 | 317 | * @next_index: one beyond the last index for this chunk |
78c1d784 | 318 | * @tags: bit-mask for tag-iterating |
21ef5339 | 319 | * @shift: shift for the node that holds our slots |
78c1d784 KK |
320 | * |
321 | * This radix tree iterator works in terms of "chunks" of slots. A chunk is a | |
322 | * subinterval of slots contained within one radix tree leaf node. It is | |
323 | * described by a pointer to its first slot and a struct radix_tree_iter | |
324 | * which holds the chunk's position in the tree and its size. For tagged | |
325 | * iteration radix_tree_iter also holds the slots' bit-mask for one chosen | |
326 | * radix tree tag. | |
327 | */ | |
328 | struct radix_tree_iter { | |
329 | unsigned long index; | |
330 | unsigned long next_index; | |
331 | unsigned long tags; | |
21ef5339 RZ |
332 | #ifdef CONFIG_RADIX_TREE_MULTIORDER |
333 | unsigned int shift; | |
334 | #endif | |
78c1d784 KK |
335 | }; |
336 | ||
21ef5339 RZ |
337 | static inline unsigned int iter_shift(struct radix_tree_iter *iter) |
338 | { | |
339 | #ifdef CONFIG_RADIX_TREE_MULTIORDER | |
340 | return iter->shift; | |
341 | #else | |
342 | return 0; | |
343 | #endif | |
344 | } | |
345 | ||
78c1d784 KK |
346 | #define RADIX_TREE_ITER_TAG_MASK 0x00FF /* tag index in lower byte */ |
347 | #define RADIX_TREE_ITER_TAGGED 0x0100 /* lookup tagged slots */ | |
348 | #define RADIX_TREE_ITER_CONTIG 0x0200 /* stop at first hole */ | |
349 | ||
350 | /** | |
351 | * radix_tree_iter_init - initialize radix tree iterator | |
352 | * | |
353 | * @iter: pointer to iterator state | |
354 | * @start: iteration starting index | |
355 | * Returns: NULL | |
356 | */ | |
357 | static __always_inline void ** | |
358 | radix_tree_iter_init(struct radix_tree_iter *iter, unsigned long start) | |
359 | { | |
360 | /* | |
361 | * Leave iter->tags uninitialized. radix_tree_next_chunk() will fill it | |
362 | * in the case of a successful tagged chunk lookup. If the lookup was | |
363 | * unsuccessful or non-tagged then nobody cares about ->tags. | |
364 | * | |
365 | * Set index to zero to bypass next_index overflow protection. | |
366 | * See the comment in radix_tree_next_chunk() for details. | |
367 | */ | |
368 | iter->index = 0; | |
369 | iter->next_index = start; | |
370 | return NULL; | |
371 | } | |
372 | ||
373 | /** | |
374 | * radix_tree_next_chunk - find next chunk of slots for iteration | |
375 | * | |
376 | * @root: radix tree root | |
377 | * @iter: iterator state | |
378 | * @flags: RADIX_TREE_ITER_* flags and tag index | |
379 | * Returns: pointer to chunk first slot, or NULL if there no more left | |
380 | * | |
381 | * This function looks up the next chunk in the radix tree starting from | |
382 | * @iter->next_index. It returns a pointer to the chunk's first slot. | |
383 | * Also it fills @iter with data about chunk: position in the tree (index), | |
384 | * its end (next_index), and constructs a bit mask for tagged iterating (tags). | |
385 | */ | |
386 | void **radix_tree_next_chunk(struct radix_tree_root *root, | |
387 | struct radix_tree_iter *iter, unsigned flags); | |
388 | ||
46437f9a MW |
389 | /** |
390 | * radix_tree_iter_retry - retry this chunk of the iteration | |
391 | * @iter: iterator state | |
392 | * | |
393 | * If we iterate over a tree protected only by the RCU lock, a race | |
394 | * against deletion or creation may result in seeing a slot for which | |
395 | * radix_tree_deref_retry() returns true. If so, call this function | |
396 | * and continue the iteration. | |
397 | */ | |
398 | static inline __must_check | |
399 | void **radix_tree_iter_retry(struct radix_tree_iter *iter) | |
400 | { | |
401 | iter->next_index = iter->index; | |
402 | return NULL; | |
403 | } | |
404 | ||
21ef5339 RZ |
405 | static inline unsigned long |
406 | __radix_tree_iter_add(struct radix_tree_iter *iter, unsigned long slots) | |
407 | { | |
408 | return iter->index + (slots << iter_shift(iter)); | |
409 | } | |
410 | ||
7165092f MW |
411 | /** |
412 | * radix_tree_iter_next - resume iterating when the chunk may be invalid | |
413 | * @iter: iterator state | |
414 | * | |
415 | * If the iterator needs to release then reacquire a lock, the chunk may | |
416 | * have been invalidated by an insertion or deletion. Call this function | |
417 | * to continue the iteration from the next index. | |
418 | */ | |
419 | static inline __must_check | |
420 | void **radix_tree_iter_next(struct radix_tree_iter *iter) | |
421 | { | |
21ef5339 | 422 | iter->next_index = __radix_tree_iter_add(iter, 1); |
7165092f MW |
423 | iter->tags = 0; |
424 | return NULL; | |
425 | } | |
426 | ||
78c1d784 KK |
427 | /** |
428 | * radix_tree_chunk_size - get current chunk size | |
429 | * | |
430 | * @iter: pointer to radix tree iterator | |
431 | * Returns: current chunk size | |
432 | */ | |
73204282 | 433 | static __always_inline long |
78c1d784 KK |
434 | radix_tree_chunk_size(struct radix_tree_iter *iter) |
435 | { | |
21ef5339 RZ |
436 | return (iter->next_index - iter->index) >> iter_shift(iter); |
437 | } | |
438 | ||
4dd6c098 | 439 | static inline struct radix_tree_node *entry_to_node(void *ptr) |
21ef5339 | 440 | { |
30ff46cc | 441 | return (void *)((unsigned long)ptr & ~RADIX_TREE_INTERNAL_NODE); |
78c1d784 KK |
442 | } |
443 | ||
444 | /** | |
445 | * radix_tree_next_slot - find next slot in chunk | |
446 | * | |
447 | * @slot: pointer to current slot | |
448 | * @iter: pointer to interator state | |
449 | * @flags: RADIX_TREE_ITER_*, should be constant | |
450 | * Returns: pointer to next slot, or NULL if there no more left | |
451 | * | |
452 | * This function updates @iter->index in the case of a successful lookup. | |
453 | * For tagged lookup it also eats @iter->tags. | |
454 | */ | |
455 | static __always_inline void ** | |
456 | radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, unsigned flags) | |
457 | { | |
458 | if (flags & RADIX_TREE_ITER_TAGGED) { | |
21ef5339 RZ |
459 | void *canon = slot; |
460 | ||
78c1d784 | 461 | iter->tags >>= 1; |
21ef5339 RZ |
462 | if (unlikely(!iter->tags)) |
463 | return NULL; | |
464 | while (IS_ENABLED(CONFIG_RADIX_TREE_MULTIORDER) && | |
b194d16c | 465 | radix_tree_is_internal_node(slot[1])) { |
4dd6c098 | 466 | if (entry_to_node(slot[1]) == canon) { |
21ef5339 RZ |
467 | iter->tags >>= 1; |
468 | iter->index = __radix_tree_iter_add(iter, 1); | |
469 | slot++; | |
470 | continue; | |
471 | } | |
472 | iter->next_index = __radix_tree_iter_add(iter, 1); | |
473 | return NULL; | |
474 | } | |
78c1d784 | 475 | if (likely(iter->tags & 1ul)) { |
21ef5339 | 476 | iter->index = __radix_tree_iter_add(iter, 1); |
78c1d784 KK |
477 | return slot + 1; |
478 | } | |
21ef5339 | 479 | if (!(flags & RADIX_TREE_ITER_CONTIG)) { |
78c1d784 KK |
480 | unsigned offset = __ffs(iter->tags); |
481 | ||
482 | iter->tags >>= offset; | |
21ef5339 | 483 | iter->index = __radix_tree_iter_add(iter, offset + 1); |
78c1d784 KK |
484 | return slot + offset + 1; |
485 | } | |
486 | } else { | |
21ef5339 RZ |
487 | long count = radix_tree_chunk_size(iter); |
488 | void *canon = slot; | |
78c1d784 | 489 | |
21ef5339 | 490 | while (--count > 0) { |
78c1d784 | 491 | slot++; |
21ef5339 RZ |
492 | iter->index = __radix_tree_iter_add(iter, 1); |
493 | ||
494 | if (IS_ENABLED(CONFIG_RADIX_TREE_MULTIORDER) && | |
b194d16c | 495 | radix_tree_is_internal_node(*slot)) { |
4dd6c098 | 496 | if (entry_to_node(*slot) == canon) |
21ef5339 | 497 | continue; |
4dd6c098 MW |
498 | iter->next_index = iter->index; |
499 | break; | |
21ef5339 RZ |
500 | } |
501 | ||
78c1d784 KK |
502 | if (likely(*slot)) |
503 | return slot; | |
fffaee36 KK |
504 | if (flags & RADIX_TREE_ITER_CONTIG) { |
505 | /* forbid switching to the next chunk */ | |
506 | iter->next_index = 0; | |
78c1d784 | 507 | break; |
fffaee36 | 508 | } |
78c1d784 KK |
509 | } |
510 | } | |
511 | return NULL; | |
512 | } | |
513 | ||
78c1d784 KK |
514 | /** |
515 | * radix_tree_for_each_slot - iterate over non-empty slots | |
516 | * | |
517 | * @slot: the void** variable for pointer to slot | |
518 | * @root: the struct radix_tree_root pointer | |
519 | * @iter: the struct radix_tree_iter pointer | |
520 | * @start: iteration starting index | |
521 | * | |
522 | * @slot points to radix tree slot, @iter->index contains its index. | |
523 | */ | |
524 | #define radix_tree_for_each_slot(slot, root, iter, start) \ | |
525 | for (slot = radix_tree_iter_init(iter, start) ; \ | |
526 | slot || (slot = radix_tree_next_chunk(root, iter, 0)) ; \ | |
527 | slot = radix_tree_next_slot(slot, iter, 0)) | |
528 | ||
529 | /** | |
530 | * radix_tree_for_each_contig - iterate over contiguous slots | |
531 | * | |
532 | * @slot: the void** variable for pointer to slot | |
533 | * @root: the struct radix_tree_root pointer | |
534 | * @iter: the struct radix_tree_iter pointer | |
535 | * @start: iteration starting index | |
536 | * | |
537 | * @slot points to radix tree slot, @iter->index contains its index. | |
538 | */ | |
539 | #define radix_tree_for_each_contig(slot, root, iter, start) \ | |
540 | for (slot = radix_tree_iter_init(iter, start) ; \ | |
541 | slot || (slot = radix_tree_next_chunk(root, iter, \ | |
542 | RADIX_TREE_ITER_CONTIG)) ; \ | |
543 | slot = radix_tree_next_slot(slot, iter, \ | |
544 | RADIX_TREE_ITER_CONTIG)) | |
545 | ||
546 | /** | |
547 | * radix_tree_for_each_tagged - iterate over tagged slots | |
548 | * | |
549 | * @slot: the void** variable for pointer to slot | |
550 | * @root: the struct radix_tree_root pointer | |
551 | * @iter: the struct radix_tree_iter pointer | |
552 | * @start: iteration starting index | |
553 | * @tag: tag index | |
554 | * | |
555 | * @slot points to radix tree slot, @iter->index contains its index. | |
556 | */ | |
557 | #define radix_tree_for_each_tagged(slot, root, iter, start, tag) \ | |
558 | for (slot = radix_tree_iter_init(iter, start) ; \ | |
559 | slot || (slot = radix_tree_next_chunk(root, iter, \ | |
560 | RADIX_TREE_ITER_TAGGED | tag)) ; \ | |
561 | slot = radix_tree_next_slot(slot, iter, \ | |
562 | RADIX_TREE_ITER_TAGGED)) | |
563 | ||
1da177e4 | 564 | #endif /* _LINUX_RADIX_TREE_H */ |