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f6bb2a2c MW |
1 | /* SPDX-License-Identifier: GPL-2.0+ */ |
2 | #ifndef _LINUX_XARRAY_H | |
3 | #define _LINUX_XARRAY_H | |
4 | /* | |
5 | * eXtensible Arrays | |
6 | * Copyright (c) 2017 Microsoft Corporation | |
3d0186bb | 7 | * Author: Matthew Wilcox <willy@infradead.org> |
3159f943 MW |
8 | * |
9 | * See Documentation/core-api/xarray.rst for how to use the XArray. | |
f6bb2a2c MW |
10 | */ |
11 | ||
3159f943 | 12 | #include <linux/bug.h> |
f8d5d0cc | 13 | #include <linux/compiler.h> |
9b89a035 | 14 | #include <linux/gfp.h> |
f8d5d0cc | 15 | #include <linux/kconfig.h> |
ad3d6c72 MW |
16 | #include <linux/kernel.h> |
17 | #include <linux/rcupdate.h> | |
f6bb2a2c | 18 | #include <linux/spinlock.h> |
3159f943 MW |
19 | #include <linux/types.h> |
20 | ||
21 | /* | |
22 | * The bottom two bits of the entry determine how the XArray interprets | |
23 | * the contents: | |
24 | * | |
25 | * 00: Pointer entry | |
26 | * 10: Internal entry | |
27 | * x1: Value entry or tagged pointer | |
28 | * | |
29 | * Attempting to store internal entries in the XArray is a bug. | |
02c02bf1 MW |
30 | * |
31 | * Most internal entries are pointers to the next node in the tree. | |
32 | * The following internal entries have a special meaning: | |
33 | * | |
34 | * 0-62: Sibling entries | |
35 | * 256: Retry entry | |
ad3d6c72 MW |
36 | * |
37 | * Errors are also represented as internal entries, but use the negative | |
38 | * space (-4094 to -2). They're never stored in the slots array; only | |
39 | * returned by the normal API. | |
3159f943 MW |
40 | */ |
41 | ||
42 | #define BITS_PER_XA_VALUE (BITS_PER_LONG - 1) | |
43 | ||
44 | /** | |
45 | * xa_mk_value() - Create an XArray entry from an integer. | |
46 | * @v: Value to store in XArray. | |
47 | * | |
48 | * Context: Any context. | |
49 | * Return: An entry suitable for storing in the XArray. | |
50 | */ | |
51 | static inline void *xa_mk_value(unsigned long v) | |
52 | { | |
53 | WARN_ON((long)v < 0); | |
54 | return (void *)((v << 1) | 1); | |
55 | } | |
56 | ||
57 | /** | |
58 | * xa_to_value() - Get value stored in an XArray entry. | |
59 | * @entry: XArray entry. | |
60 | * | |
61 | * Context: Any context. | |
62 | * Return: The value stored in the XArray entry. | |
63 | */ | |
64 | static inline unsigned long xa_to_value(const void *entry) | |
65 | { | |
66 | return (unsigned long)entry >> 1; | |
67 | } | |
68 | ||
69 | /** | |
70 | * xa_is_value() - Determine if an entry is a value. | |
71 | * @entry: XArray entry. | |
72 | * | |
73 | * Context: Any context. | |
74 | * Return: True if the entry is a value, false if it is a pointer. | |
75 | */ | |
76 | static inline bool xa_is_value(const void *entry) | |
77 | { | |
78 | return (unsigned long)entry & 1; | |
79 | } | |
80 | ||
81 | /** | |
82 | * xa_tag_pointer() - Create an XArray entry for a tagged pointer. | |
83 | * @p: Plain pointer. | |
84 | * @tag: Tag value (0, 1 or 3). | |
85 | * | |
86 | * If the user of the XArray prefers, they can tag their pointers instead | |
87 | * of storing value entries. Three tags are available (0, 1 and 3). | |
88 | * These are distinct from the xa_mark_t as they are not replicated up | |
89 | * through the array and cannot be searched for. | |
90 | * | |
91 | * Context: Any context. | |
92 | * Return: An XArray entry. | |
93 | */ | |
94 | static inline void *xa_tag_pointer(void *p, unsigned long tag) | |
95 | { | |
96 | return (void *)((unsigned long)p | tag); | |
97 | } | |
98 | ||
99 | /** | |
100 | * xa_untag_pointer() - Turn an XArray entry into a plain pointer. | |
101 | * @entry: XArray entry. | |
102 | * | |
103 | * If you have stored a tagged pointer in the XArray, call this function | |
104 | * to get the untagged version of the pointer. | |
105 | * | |
106 | * Context: Any context. | |
107 | * Return: A pointer. | |
108 | */ | |
109 | static inline void *xa_untag_pointer(void *entry) | |
110 | { | |
111 | return (void *)((unsigned long)entry & ~3UL); | |
112 | } | |
113 | ||
114 | /** | |
115 | * xa_pointer_tag() - Get the tag stored in an XArray entry. | |
116 | * @entry: XArray entry. | |
117 | * | |
118 | * If you have stored a tagged pointer in the XArray, call this function | |
119 | * to get the tag of that pointer. | |
120 | * | |
121 | * Context: Any context. | |
122 | * Return: A tag. | |
123 | */ | |
124 | static inline unsigned int xa_pointer_tag(void *entry) | |
125 | { | |
126 | return (unsigned long)entry & 3UL; | |
127 | } | |
f6bb2a2c | 128 | |
02c02bf1 MW |
129 | /* |
130 | * xa_mk_internal() - Create an internal entry. | |
131 | * @v: Value to turn into an internal entry. | |
132 | * | |
133 | * Context: Any context. | |
134 | * Return: An XArray internal entry corresponding to this value. | |
135 | */ | |
136 | static inline void *xa_mk_internal(unsigned long v) | |
137 | { | |
138 | return (void *)((v << 2) | 2); | |
139 | } | |
140 | ||
141 | /* | |
142 | * xa_to_internal() - Extract the value from an internal entry. | |
143 | * @entry: XArray entry. | |
144 | * | |
145 | * Context: Any context. | |
146 | * Return: The value which was stored in the internal entry. | |
147 | */ | |
148 | static inline unsigned long xa_to_internal(const void *entry) | |
149 | { | |
150 | return (unsigned long)entry >> 2; | |
151 | } | |
152 | ||
153 | /* | |
154 | * xa_is_internal() - Is the entry an internal entry? | |
155 | * @entry: XArray entry. | |
156 | * | |
157 | * Context: Any context. | |
158 | * Return: %true if the entry is an internal entry. | |
159 | */ | |
160 | static inline bool xa_is_internal(const void *entry) | |
161 | { | |
162 | return ((unsigned long)entry & 3) == 2; | |
163 | } | |
164 | ||
ad3d6c72 MW |
165 | /** |
166 | * xa_is_err() - Report whether an XArray operation returned an error | |
167 | * @entry: Result from calling an XArray function | |
168 | * | |
169 | * If an XArray operation cannot complete an operation, it will return | |
170 | * a special value indicating an error. This function tells you | |
171 | * whether an error occurred; xa_err() tells you which error occurred. | |
172 | * | |
173 | * Context: Any context. | |
174 | * Return: %true if the entry indicates an error. | |
175 | */ | |
176 | static inline bool xa_is_err(const void *entry) | |
177 | { | |
178 | return unlikely(xa_is_internal(entry)); | |
179 | } | |
180 | ||
181 | /** | |
182 | * xa_err() - Turn an XArray result into an errno. | |
183 | * @entry: Result from calling an XArray function. | |
184 | * | |
185 | * If an XArray operation cannot complete an operation, it will return | |
186 | * a special pointer value which encodes an errno. This function extracts | |
187 | * the errno from the pointer value, or returns 0 if the pointer does not | |
188 | * represent an errno. | |
189 | * | |
190 | * Context: Any context. | |
191 | * Return: A negative errno or 0. | |
192 | */ | |
193 | static inline int xa_err(void *entry) | |
194 | { | |
195 | /* xa_to_internal() would not do sign extension. */ | |
196 | if (xa_is_err(entry)) | |
197 | return (long)entry >> 2; | |
198 | return 0; | |
199 | } | |
200 | ||
9b89a035 MW |
201 | typedef unsigned __bitwise xa_mark_t; |
202 | #define XA_MARK_0 ((__force xa_mark_t)0U) | |
203 | #define XA_MARK_1 ((__force xa_mark_t)1U) | |
204 | #define XA_MARK_2 ((__force xa_mark_t)2U) | |
205 | #define XA_PRESENT ((__force xa_mark_t)8U) | |
206 | #define XA_MARK_MAX XA_MARK_2 | |
207 | ||
58d6ea30 MW |
208 | enum xa_lock_type { |
209 | XA_LOCK_IRQ = 1, | |
210 | XA_LOCK_BH = 2, | |
211 | }; | |
212 | ||
9b89a035 MW |
213 | /* |
214 | * Values for xa_flags. The radix tree stores its GFP flags in the xa_flags, | |
215 | * and we remain compatible with that. | |
216 | */ | |
58d6ea30 MW |
217 | #define XA_FLAGS_LOCK_IRQ ((__force gfp_t)XA_LOCK_IRQ) |
218 | #define XA_FLAGS_LOCK_BH ((__force gfp_t)XA_LOCK_BH) | |
9b89a035 MW |
219 | #define XA_FLAGS_MARK(mark) ((__force gfp_t)((1U << __GFP_BITS_SHIFT) << \ |
220 | (__force unsigned)(mark))) | |
221 | ||
f8d5d0cc MW |
222 | /** |
223 | * struct xarray - The anchor of the XArray. | |
224 | * @xa_lock: Lock that protects the contents of the XArray. | |
225 | * | |
226 | * To use the xarray, define it statically or embed it in your data structure. | |
227 | * It is a very small data structure, so it does not usually make sense to | |
228 | * allocate it separately and keep a pointer to it in your data structure. | |
229 | * | |
230 | * You may use the xa_lock to protect your own data structures as well. | |
231 | */ | |
232 | /* | |
233 | * If all of the entries in the array are NULL, @xa_head is a NULL pointer. | |
234 | * If the only non-NULL entry in the array is at index 0, @xa_head is that | |
235 | * entry. If any other entry in the array is non-NULL, @xa_head points | |
236 | * to an @xa_node. | |
237 | */ | |
238 | struct xarray { | |
239 | spinlock_t xa_lock; | |
240 | /* private: The rest of the data structure is not to be used directly. */ | |
241 | gfp_t xa_flags; | |
242 | void __rcu * xa_head; | |
243 | }; | |
244 | ||
245 | #define XARRAY_INIT(name, flags) { \ | |
246 | .xa_lock = __SPIN_LOCK_UNLOCKED(name.xa_lock), \ | |
247 | .xa_flags = flags, \ | |
248 | .xa_head = NULL, \ | |
249 | } | |
250 | ||
251 | /** | |
252 | * DEFINE_XARRAY_FLAGS() - Define an XArray with custom flags. | |
253 | * @name: A string that names your XArray. | |
254 | * @flags: XA_FLAG values. | |
255 | * | |
256 | * This is intended for file scope definitions of XArrays. It declares | |
257 | * and initialises an empty XArray with the chosen name and flags. It is | |
258 | * equivalent to calling xa_init_flags() on the array, but it does the | |
259 | * initialisation at compiletime instead of runtime. | |
260 | */ | |
261 | #define DEFINE_XARRAY_FLAGS(name, flags) \ | |
262 | struct xarray name = XARRAY_INIT(name, flags) | |
263 | ||
264 | /** | |
265 | * DEFINE_XARRAY() - Define an XArray. | |
266 | * @name: A string that names your XArray. | |
267 | * | |
268 | * This is intended for file scope definitions of XArrays. It declares | |
269 | * and initialises an empty XArray with the chosen name. It is equivalent | |
270 | * to calling xa_init() on the array, but it does the initialisation at | |
271 | * compiletime instead of runtime. | |
272 | */ | |
273 | #define DEFINE_XARRAY(name) DEFINE_XARRAY_FLAGS(name, 0) | |
274 | ||
275 | void xa_init_flags(struct xarray *, gfp_t flags); | |
ad3d6c72 | 276 | void *xa_load(struct xarray *, unsigned long index); |
58d6ea30 | 277 | void *xa_store(struct xarray *, unsigned long index, void *entry, gfp_t); |
41aec91f MW |
278 | void *xa_cmpxchg(struct xarray *, unsigned long index, |
279 | void *old, void *entry, gfp_t); | |
9b89a035 MW |
280 | bool xa_get_mark(struct xarray *, unsigned long index, xa_mark_t); |
281 | void xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); | |
282 | void xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); | |
b803b428 MW |
283 | void *xa_find(struct xarray *xa, unsigned long *index, |
284 | unsigned long max, xa_mark_t) __attribute__((nonnull(2))); | |
285 | void *xa_find_after(struct xarray *xa, unsigned long *index, | |
286 | unsigned long max, xa_mark_t) __attribute__((nonnull(2))); | |
f8d5d0cc MW |
287 | |
288 | /** | |
289 | * xa_init() - Initialise an empty XArray. | |
290 | * @xa: XArray. | |
291 | * | |
292 | * An empty XArray is full of NULL entries. | |
293 | * | |
294 | * Context: Any context. | |
295 | */ | |
296 | static inline void xa_init(struct xarray *xa) | |
297 | { | |
298 | xa_init_flags(xa, 0); | |
299 | } | |
300 | ||
ad3d6c72 MW |
301 | /** |
302 | * xa_empty() - Determine if an array has any present entries. | |
303 | * @xa: XArray. | |
304 | * | |
305 | * Context: Any context. | |
306 | * Return: %true if the array contains only NULL pointers. | |
307 | */ | |
308 | static inline bool xa_empty(const struct xarray *xa) | |
309 | { | |
310 | return xa->xa_head == NULL; | |
311 | } | |
312 | ||
9b89a035 MW |
313 | /** |
314 | * xa_marked() - Inquire whether any entry in this array has a mark set | |
315 | * @xa: Array | |
316 | * @mark: Mark value | |
317 | * | |
318 | * Context: Any context. | |
319 | * Return: %true if any entry has this mark set. | |
320 | */ | |
321 | static inline bool xa_marked(const struct xarray *xa, xa_mark_t mark) | |
322 | { | |
323 | return xa->xa_flags & XA_FLAGS_MARK(mark); | |
324 | } | |
325 | ||
58d6ea30 MW |
326 | /** |
327 | * xa_erase() - Erase this entry from the XArray. | |
328 | * @xa: XArray. | |
329 | * @index: Index of entry. | |
330 | * | |
331 | * This function is the equivalent of calling xa_store() with %NULL as | |
332 | * the third argument. The XArray does not need to allocate memory, so | |
333 | * the user does not need to provide GFP flags. | |
334 | * | |
335 | * Context: Process context. Takes and releases the xa_lock. | |
336 | * Return: The entry which used to be at this index. | |
337 | */ | |
338 | static inline void *xa_erase(struct xarray *xa, unsigned long index) | |
339 | { | |
340 | return xa_store(xa, index, NULL, 0); | |
341 | } | |
342 | ||
41aec91f MW |
343 | /** |
344 | * xa_insert() - Store this entry in the XArray unless another entry is | |
345 | * already present. | |
346 | * @xa: XArray. | |
347 | * @index: Index into array. | |
348 | * @entry: New entry. | |
349 | * @gfp: Memory allocation flags. | |
350 | * | |
351 | * If you would rather see the existing entry in the array, use xa_cmpxchg(). | |
352 | * This function is for users who don't care what the entry is, only that | |
353 | * one is present. | |
354 | * | |
355 | * Context: Process context. Takes and releases the xa_lock. | |
356 | * May sleep if the @gfp flags permit. | |
357 | * Return: 0 if the store succeeded. -EEXIST if another entry was present. | |
358 | * -ENOMEM if memory could not be allocated. | |
359 | */ | |
360 | static inline int xa_insert(struct xarray *xa, unsigned long index, | |
361 | void *entry, gfp_t gfp) | |
362 | { | |
363 | void *curr = xa_cmpxchg(xa, index, NULL, entry, gfp); | |
364 | if (!curr) | |
365 | return 0; | |
366 | if (xa_is_err(curr)) | |
367 | return xa_err(curr); | |
368 | return -EEXIST; | |
369 | } | |
370 | ||
b803b428 MW |
371 | /** |
372 | * xa_for_each() - Iterate over a portion of an XArray. | |
373 | * @xa: XArray. | |
374 | * @entry: Entry retrieved from array. | |
375 | * @index: Index of @entry. | |
376 | * @max: Maximum index to retrieve from array. | |
377 | * @filter: Selection criterion. | |
378 | * | |
379 | * Initialise @index to the lowest index you want to retrieve from the | |
380 | * array. During the iteration, @entry will have the value of the entry | |
381 | * stored in @xa at @index. The iteration will skip all entries in the | |
382 | * array which do not match @filter. You may modify @index during the | |
383 | * iteration if you want to skip or reprocess indices. It is safe to modify | |
384 | * the array during the iteration. At the end of the iteration, @entry will | |
385 | * be set to NULL and @index will have a value less than or equal to max. | |
386 | * | |
387 | * xa_for_each() is O(n.log(n)) while xas_for_each() is O(n). You have | |
388 | * to handle your own locking with xas_for_each(), and if you have to unlock | |
389 | * after each iteration, it will also end up being O(n.log(n)). xa_for_each() | |
390 | * will spin if it hits a retry entry; if you intend to see retry entries, | |
391 | * you should use the xas_for_each() iterator instead. The xas_for_each() | |
392 | * iterator will expand into more inline code than xa_for_each(). | |
393 | * | |
394 | * Context: Any context. Takes and releases the RCU lock. | |
395 | */ | |
396 | #define xa_for_each(xa, entry, index, max, filter) \ | |
397 | for (entry = xa_find(xa, &index, max, filter); entry; \ | |
398 | entry = xa_find_after(xa, &index, max, filter)) | |
399 | ||
f6bb2a2c MW |
400 | #define xa_trylock(xa) spin_trylock(&(xa)->xa_lock) |
401 | #define xa_lock(xa) spin_lock(&(xa)->xa_lock) | |
402 | #define xa_unlock(xa) spin_unlock(&(xa)->xa_lock) | |
403 | #define xa_lock_bh(xa) spin_lock_bh(&(xa)->xa_lock) | |
404 | #define xa_unlock_bh(xa) spin_unlock_bh(&(xa)->xa_lock) | |
405 | #define xa_lock_irq(xa) spin_lock_irq(&(xa)->xa_lock) | |
406 | #define xa_unlock_irq(xa) spin_unlock_irq(&(xa)->xa_lock) | |
407 | #define xa_lock_irqsave(xa, flags) \ | |
408 | spin_lock_irqsave(&(xa)->xa_lock, flags) | |
409 | #define xa_unlock_irqrestore(xa, flags) \ | |
410 | spin_unlock_irqrestore(&(xa)->xa_lock, flags) | |
411 | ||
9b89a035 | 412 | /* |
58d6ea30 MW |
413 | * Versions of the normal API which require the caller to hold the |
414 | * xa_lock. If the GFP flags allow it, they will drop the lock to | |
415 | * allocate memory, then reacquire it afterwards. These functions | |
416 | * may also re-enable interrupts if the XArray flags indicate the | |
417 | * locking should be interrupt safe. | |
418 | */ | |
419 | void *__xa_erase(struct xarray *, unsigned long index); | |
420 | void *__xa_store(struct xarray *, unsigned long index, void *entry, gfp_t); | |
41aec91f MW |
421 | void *__xa_cmpxchg(struct xarray *, unsigned long index, void *old, |
422 | void *entry, gfp_t); | |
9b89a035 MW |
423 | void __xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); |
424 | void __xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); | |
425 | ||
41aec91f MW |
426 | /** |
427 | * __xa_insert() - Store this entry in the XArray unless another entry is | |
428 | * already present. | |
429 | * @xa: XArray. | |
430 | * @index: Index into array. | |
431 | * @entry: New entry. | |
432 | * @gfp: Memory allocation flags. | |
433 | * | |
434 | * If you would rather see the existing entry in the array, use __xa_cmpxchg(). | |
435 | * This function is for users who don't care what the entry is, only that | |
436 | * one is present. | |
437 | * | |
438 | * Context: Any context. Expects xa_lock to be held on entry. May | |
439 | * release and reacquire xa_lock if the @gfp flags permit. | |
440 | * Return: 0 if the store succeeded. -EEXIST if another entry was present. | |
441 | * -ENOMEM if memory could not be allocated. | |
442 | */ | |
443 | static inline int __xa_insert(struct xarray *xa, unsigned long index, | |
444 | void *entry, gfp_t gfp) | |
445 | { | |
446 | void *curr = __xa_cmpxchg(xa, index, NULL, entry, gfp); | |
447 | if (!curr) | |
448 | return 0; | |
449 | if (xa_is_err(curr)) | |
450 | return xa_err(curr); | |
451 | return -EEXIST; | |
452 | } | |
453 | ||
58d6ea30 MW |
454 | /** |
455 | * xa_erase_bh() - Erase this entry from the XArray. | |
456 | * @xa: XArray. | |
457 | * @index: Index of entry. | |
458 | * | |
459 | * This function is the equivalent of calling xa_store() with %NULL as | |
460 | * the third argument. The XArray does not need to allocate memory, so | |
461 | * the user does not need to provide GFP flags. | |
462 | * | |
463 | * Context: Process context. Takes and releases the xa_lock while | |
464 | * disabling softirqs. | |
465 | * Return: The entry which used to be at this index. | |
466 | */ | |
467 | static inline void *xa_erase_bh(struct xarray *xa, unsigned long index) | |
468 | { | |
469 | void *entry; | |
470 | ||
471 | xa_lock_bh(xa); | |
472 | entry = __xa_erase(xa, index); | |
473 | xa_unlock_bh(xa); | |
474 | ||
475 | return entry; | |
476 | } | |
477 | ||
478 | /** | |
479 | * xa_erase_irq() - Erase this entry from the XArray. | |
480 | * @xa: XArray. | |
481 | * @index: Index of entry. | |
482 | * | |
483 | * This function is the equivalent of calling xa_store() with %NULL as | |
484 | * the third argument. The XArray does not need to allocate memory, so | |
485 | * the user does not need to provide GFP flags. | |
486 | * | |
487 | * Context: Process context. Takes and releases the xa_lock while | |
488 | * disabling interrupts. | |
489 | * Return: The entry which used to be at this index. | |
490 | */ | |
491 | static inline void *xa_erase_irq(struct xarray *xa, unsigned long index) | |
492 | { | |
493 | void *entry; | |
494 | ||
495 | xa_lock_irq(xa); | |
496 | entry = __xa_erase(xa, index); | |
497 | xa_unlock_irq(xa); | |
498 | ||
499 | return entry; | |
500 | } | |
501 | ||
02c02bf1 MW |
502 | /* Everything below here is the Advanced API. Proceed with caution. */ |
503 | ||
504 | /* | |
505 | * The xarray is constructed out of a set of 'chunks' of pointers. Choosing | |
506 | * the best chunk size requires some tradeoffs. A power of two recommends | |
507 | * itself so that we can walk the tree based purely on shifts and masks. | |
508 | * Generally, the larger the better; as the number of slots per level of the | |
509 | * tree increases, the less tall the tree needs to be. But that needs to be | |
510 | * balanced against the memory consumption of each node. On a 64-bit system, | |
511 | * xa_node is currently 576 bytes, and we get 7 of them per 4kB page. If we | |
512 | * doubled the number of slots per node, we'd get only 3 nodes per 4kB page. | |
513 | */ | |
514 | #ifndef XA_CHUNK_SHIFT | |
515 | #define XA_CHUNK_SHIFT (CONFIG_BASE_SMALL ? 4 : 6) | |
516 | #endif | |
517 | #define XA_CHUNK_SIZE (1UL << XA_CHUNK_SHIFT) | |
518 | #define XA_CHUNK_MASK (XA_CHUNK_SIZE - 1) | |
01959dfe MW |
519 | #define XA_MAX_MARKS 3 |
520 | #define XA_MARK_LONGS DIV_ROUND_UP(XA_CHUNK_SIZE, BITS_PER_LONG) | |
521 | ||
522 | /* | |
523 | * @count is the count of every non-NULL element in the ->slots array | |
524 | * whether that is a value entry, a retry entry, a user pointer, | |
525 | * a sibling entry or a pointer to the next level of the tree. | |
526 | * @nr_values is the count of every element in ->slots which is | |
527 | * either a value entry or a sibling of a value entry. | |
528 | */ | |
529 | struct xa_node { | |
530 | unsigned char shift; /* Bits remaining in each slot */ | |
531 | unsigned char offset; /* Slot offset in parent */ | |
532 | unsigned char count; /* Total entry count */ | |
533 | unsigned char nr_values; /* Value entry count */ | |
534 | struct xa_node __rcu *parent; /* NULL at top of tree */ | |
535 | struct xarray *array; /* The array we belong to */ | |
536 | union { | |
537 | struct list_head private_list; /* For tree user */ | |
538 | struct rcu_head rcu_head; /* Used when freeing node */ | |
539 | }; | |
540 | void __rcu *slots[XA_CHUNK_SIZE]; | |
541 | union { | |
542 | unsigned long tags[XA_MAX_MARKS][XA_MARK_LONGS]; | |
543 | unsigned long marks[XA_MAX_MARKS][XA_MARK_LONGS]; | |
544 | }; | |
545 | }; | |
02c02bf1 | 546 | |
ad3d6c72 MW |
547 | void xa_dump(const struct xarray *); |
548 | void xa_dump_node(const struct xa_node *); | |
549 | ||
550 | #ifdef XA_DEBUG | |
551 | #define XA_BUG_ON(xa, x) do { \ | |
552 | if (x) { \ | |
553 | xa_dump(xa); \ | |
554 | BUG(); \ | |
555 | } \ | |
556 | } while (0) | |
557 | #define XA_NODE_BUG_ON(node, x) do { \ | |
558 | if (x) { \ | |
559 | if (node) xa_dump_node(node); \ | |
560 | BUG(); \ | |
561 | } \ | |
562 | } while (0) | |
563 | #else | |
564 | #define XA_BUG_ON(xa, x) do { } while (0) | |
565 | #define XA_NODE_BUG_ON(node, x) do { } while (0) | |
566 | #endif | |
567 | ||
568 | /* Private */ | |
569 | static inline void *xa_head(const struct xarray *xa) | |
570 | { | |
571 | return rcu_dereference_check(xa->xa_head, | |
572 | lockdep_is_held(&xa->xa_lock)); | |
573 | } | |
574 | ||
575 | /* Private */ | |
576 | static inline void *xa_head_locked(const struct xarray *xa) | |
577 | { | |
578 | return rcu_dereference_protected(xa->xa_head, | |
579 | lockdep_is_held(&xa->xa_lock)); | |
580 | } | |
581 | ||
582 | /* Private */ | |
583 | static inline void *xa_entry(const struct xarray *xa, | |
584 | const struct xa_node *node, unsigned int offset) | |
585 | { | |
586 | XA_NODE_BUG_ON(node, offset >= XA_CHUNK_SIZE); | |
587 | return rcu_dereference_check(node->slots[offset], | |
588 | lockdep_is_held(&xa->xa_lock)); | |
589 | } | |
590 | ||
591 | /* Private */ | |
592 | static inline void *xa_entry_locked(const struct xarray *xa, | |
593 | const struct xa_node *node, unsigned int offset) | |
594 | { | |
595 | XA_NODE_BUG_ON(node, offset >= XA_CHUNK_SIZE); | |
596 | return rcu_dereference_protected(node->slots[offset], | |
597 | lockdep_is_held(&xa->xa_lock)); | |
598 | } | |
599 | ||
9b89a035 MW |
600 | /* Private */ |
601 | static inline struct xa_node *xa_parent(const struct xarray *xa, | |
602 | const struct xa_node *node) | |
603 | { | |
604 | return rcu_dereference_check(node->parent, | |
605 | lockdep_is_held(&xa->xa_lock)); | |
606 | } | |
607 | ||
608 | /* Private */ | |
609 | static inline struct xa_node *xa_parent_locked(const struct xarray *xa, | |
610 | const struct xa_node *node) | |
611 | { | |
612 | return rcu_dereference_protected(node->parent, | |
613 | lockdep_is_held(&xa->xa_lock)); | |
614 | } | |
615 | ||
58d6ea30 MW |
616 | /* Private */ |
617 | static inline void *xa_mk_node(const struct xa_node *node) | |
618 | { | |
619 | return (void *)((unsigned long)node | 2); | |
620 | } | |
621 | ||
ad3d6c72 MW |
622 | /* Private */ |
623 | static inline struct xa_node *xa_to_node(const void *entry) | |
624 | { | |
625 | return (struct xa_node *)((unsigned long)entry - 2); | |
626 | } | |
627 | ||
02c02bf1 MW |
628 | /* Private */ |
629 | static inline bool xa_is_node(const void *entry) | |
630 | { | |
631 | return xa_is_internal(entry) && (unsigned long)entry > 4096; | |
632 | } | |
633 | ||
634 | /* Private */ | |
635 | static inline void *xa_mk_sibling(unsigned int offset) | |
636 | { | |
637 | return xa_mk_internal(offset); | |
638 | } | |
639 | ||
640 | /* Private */ | |
641 | static inline unsigned long xa_to_sibling(const void *entry) | |
642 | { | |
643 | return xa_to_internal(entry); | |
644 | } | |
645 | ||
646 | /** | |
647 | * xa_is_sibling() - Is the entry a sibling entry? | |
648 | * @entry: Entry retrieved from the XArray | |
649 | * | |
650 | * Return: %true if the entry is a sibling entry. | |
651 | */ | |
652 | static inline bool xa_is_sibling(const void *entry) | |
653 | { | |
654 | return IS_ENABLED(CONFIG_XARRAY_MULTI) && xa_is_internal(entry) && | |
655 | (entry < xa_mk_sibling(XA_CHUNK_SIZE - 1)); | |
656 | } | |
657 | ||
658 | #define XA_RETRY_ENTRY xa_mk_internal(256) | |
659 | ||
ad3d6c72 MW |
660 | /** |
661 | * xa_is_retry() - Is the entry a retry entry? | |
662 | * @entry: Entry retrieved from the XArray | |
663 | * | |
664 | * Return: %true if the entry is a retry entry. | |
665 | */ | |
666 | static inline bool xa_is_retry(const void *entry) | |
667 | { | |
668 | return unlikely(entry == XA_RETRY_ENTRY); | |
669 | } | |
670 | ||
671 | /** | |
672 | * typedef xa_update_node_t - A callback function from the XArray. | |
673 | * @node: The node which is being processed | |
674 | * | |
675 | * This function is called every time the XArray updates the count of | |
676 | * present and value entries in a node. It allows advanced users to | |
677 | * maintain the private_list in the node. | |
678 | * | |
679 | * Context: The xa_lock is held and interrupts may be disabled. | |
680 | * Implementations should not drop the xa_lock, nor re-enable | |
681 | * interrupts. | |
682 | */ | |
683 | typedef void (*xa_update_node_t)(struct xa_node *node); | |
684 | ||
685 | /* | |
686 | * The xa_state is opaque to its users. It contains various different pieces | |
687 | * of state involved in the current operation on the XArray. It should be | |
688 | * declared on the stack and passed between the various internal routines. | |
689 | * The various elements in it should not be accessed directly, but only | |
690 | * through the provided accessor functions. The below documentation is for | |
691 | * the benefit of those working on the code, not for users of the XArray. | |
692 | * | |
693 | * @xa_node usually points to the xa_node containing the slot we're operating | |
694 | * on (and @xa_offset is the offset in the slots array). If there is a | |
695 | * single entry in the array at index 0, there are no allocated xa_nodes to | |
696 | * point to, and so we store %NULL in @xa_node. @xa_node is set to | |
697 | * the value %XAS_RESTART if the xa_state is not walked to the correct | |
698 | * position in the tree of nodes for this operation. If an error occurs | |
699 | * during an operation, it is set to an %XAS_ERROR value. If we run off the | |
700 | * end of the allocated nodes, it is set to %XAS_BOUNDS. | |
701 | */ | |
702 | struct xa_state { | |
703 | struct xarray *xa; | |
704 | unsigned long xa_index; | |
705 | unsigned char xa_shift; | |
706 | unsigned char xa_sibs; | |
707 | unsigned char xa_offset; | |
708 | unsigned char xa_pad; /* Helps gcc generate better code */ | |
709 | struct xa_node *xa_node; | |
710 | struct xa_node *xa_alloc; | |
711 | xa_update_node_t xa_update; | |
712 | }; | |
713 | ||
714 | /* | |
715 | * We encode errnos in the xas->xa_node. If an error has happened, we need to | |
716 | * drop the lock to fix it, and once we've done so the xa_state is invalid. | |
717 | */ | |
718 | #define XA_ERROR(errno) ((struct xa_node *)(((unsigned long)errno << 2) | 2UL)) | |
719 | #define XAS_BOUNDS ((struct xa_node *)1UL) | |
720 | #define XAS_RESTART ((struct xa_node *)3UL) | |
721 | ||
722 | #define __XA_STATE(array, index, shift, sibs) { \ | |
723 | .xa = array, \ | |
724 | .xa_index = index, \ | |
725 | .xa_shift = shift, \ | |
726 | .xa_sibs = sibs, \ | |
727 | .xa_offset = 0, \ | |
728 | .xa_pad = 0, \ | |
729 | .xa_node = XAS_RESTART, \ | |
730 | .xa_alloc = NULL, \ | |
731 | .xa_update = NULL \ | |
732 | } | |
733 | ||
734 | /** | |
735 | * XA_STATE() - Declare an XArray operation state. | |
736 | * @name: Name of this operation state (usually xas). | |
737 | * @array: Array to operate on. | |
738 | * @index: Initial index of interest. | |
739 | * | |
740 | * Declare and initialise an xa_state on the stack. | |
741 | */ | |
742 | #define XA_STATE(name, array, index) \ | |
743 | struct xa_state name = __XA_STATE(array, index, 0, 0) | |
744 | ||
745 | /** | |
746 | * XA_STATE_ORDER() - Declare an XArray operation state. | |
747 | * @name: Name of this operation state (usually xas). | |
748 | * @array: Array to operate on. | |
749 | * @index: Initial index of interest. | |
750 | * @order: Order of entry. | |
751 | * | |
752 | * Declare and initialise an xa_state on the stack. This variant of | |
753 | * XA_STATE() allows you to specify the 'order' of the element you | |
754 | * want to operate on.` | |
755 | */ | |
756 | #define XA_STATE_ORDER(name, array, index, order) \ | |
757 | struct xa_state name = __XA_STATE(array, \ | |
758 | (index >> order) << order, \ | |
759 | order - (order % XA_CHUNK_SHIFT), \ | |
760 | (1U << (order % XA_CHUNK_SHIFT)) - 1) | |
761 | ||
762 | #define xas_marked(xas, mark) xa_marked((xas)->xa, (mark)) | |
763 | #define xas_trylock(xas) xa_trylock((xas)->xa) | |
764 | #define xas_lock(xas) xa_lock((xas)->xa) | |
765 | #define xas_unlock(xas) xa_unlock((xas)->xa) | |
766 | #define xas_lock_bh(xas) xa_lock_bh((xas)->xa) | |
767 | #define xas_unlock_bh(xas) xa_unlock_bh((xas)->xa) | |
768 | #define xas_lock_irq(xas) xa_lock_irq((xas)->xa) | |
769 | #define xas_unlock_irq(xas) xa_unlock_irq((xas)->xa) | |
770 | #define xas_lock_irqsave(xas, flags) \ | |
771 | xa_lock_irqsave((xas)->xa, flags) | |
772 | #define xas_unlock_irqrestore(xas, flags) \ | |
773 | xa_unlock_irqrestore((xas)->xa, flags) | |
774 | ||
775 | /** | |
776 | * xas_error() - Return an errno stored in the xa_state. | |
777 | * @xas: XArray operation state. | |
778 | * | |
779 | * Return: 0 if no error has been noted. A negative errno if one has. | |
780 | */ | |
781 | static inline int xas_error(const struct xa_state *xas) | |
782 | { | |
783 | return xa_err(xas->xa_node); | |
784 | } | |
785 | ||
786 | /** | |
787 | * xas_set_err() - Note an error in the xa_state. | |
788 | * @xas: XArray operation state. | |
789 | * @err: Negative error number. | |
790 | * | |
791 | * Only call this function with a negative @err; zero or positive errors | |
792 | * will probably not behave the way you think they should. If you want | |
793 | * to clear the error from an xa_state, use xas_reset(). | |
794 | */ | |
795 | static inline void xas_set_err(struct xa_state *xas, long err) | |
796 | { | |
797 | xas->xa_node = XA_ERROR(err); | |
798 | } | |
799 | ||
800 | /** | |
801 | * xas_invalid() - Is the xas in a retry or error state? | |
802 | * @xas: XArray operation state. | |
803 | * | |
804 | * Return: %true if the xas cannot be used for operations. | |
805 | */ | |
806 | static inline bool xas_invalid(const struct xa_state *xas) | |
807 | { | |
808 | return (unsigned long)xas->xa_node & 3; | |
809 | } | |
810 | ||
811 | /** | |
812 | * xas_valid() - Is the xas a valid cursor into the array? | |
813 | * @xas: XArray operation state. | |
814 | * | |
815 | * Return: %true if the xas can be used for operations. | |
816 | */ | |
817 | static inline bool xas_valid(const struct xa_state *xas) | |
818 | { | |
819 | return !xas_invalid(xas); | |
820 | } | |
821 | ||
9b89a035 MW |
822 | /* True if the pointer is something other than a node */ |
823 | static inline bool xas_not_node(struct xa_node *node) | |
824 | { | |
825 | return ((unsigned long)node & 3) || !node; | |
826 | } | |
827 | ||
58d6ea30 MW |
828 | /* True if the node represents head-of-tree, RESTART or BOUNDS */ |
829 | static inline bool xas_top(struct xa_node *node) | |
830 | { | |
831 | return node <= XAS_RESTART; | |
832 | } | |
833 | ||
ad3d6c72 MW |
834 | /** |
835 | * xas_reset() - Reset an XArray operation state. | |
836 | * @xas: XArray operation state. | |
837 | * | |
838 | * Resets the error or walk state of the @xas so future walks of the | |
839 | * array will start from the root. Use this if you have dropped the | |
840 | * xarray lock and want to reuse the xa_state. | |
841 | * | |
842 | * Context: Any context. | |
843 | */ | |
844 | static inline void xas_reset(struct xa_state *xas) | |
845 | { | |
846 | xas->xa_node = XAS_RESTART; | |
847 | } | |
848 | ||
849 | /** | |
850 | * xas_retry() - Retry the operation if appropriate. | |
851 | * @xas: XArray operation state. | |
852 | * @entry: Entry from xarray. | |
853 | * | |
854 | * The advanced functions may sometimes return an internal entry, such as | |
855 | * a retry entry or a zero entry. This function sets up the @xas to restart | |
856 | * the walk from the head of the array if needed. | |
857 | * | |
858 | * Context: Any context. | |
859 | * Return: true if the operation needs to be retried. | |
860 | */ | |
861 | static inline bool xas_retry(struct xa_state *xas, const void *entry) | |
862 | { | |
863 | if (!xa_is_retry(entry)) | |
864 | return false; | |
865 | xas_reset(xas); | |
866 | return true; | |
867 | } | |
868 | ||
869 | void *xas_load(struct xa_state *); | |
58d6ea30 | 870 | void *xas_store(struct xa_state *, void *entry); |
b803b428 | 871 | void *xas_find(struct xa_state *, unsigned long max); |
ad3d6c72 | 872 | |
9b89a035 MW |
873 | bool xas_get_mark(const struct xa_state *, xa_mark_t); |
874 | void xas_set_mark(const struct xa_state *, xa_mark_t); | |
875 | void xas_clear_mark(const struct xa_state *, xa_mark_t); | |
b803b428 | 876 | void *xas_find_marked(struct xa_state *, unsigned long max, xa_mark_t); |
58d6ea30 MW |
877 | void xas_init_marks(const struct xa_state *); |
878 | ||
879 | bool xas_nomem(struct xa_state *, gfp_t); | |
b803b428 | 880 | void xas_pause(struct xa_state *); |
9b89a035 | 881 | |
ad3d6c72 MW |
882 | /** |
883 | * xas_reload() - Refetch an entry from the xarray. | |
884 | * @xas: XArray operation state. | |
885 | * | |
886 | * Use this function to check that a previously loaded entry still has | |
887 | * the same value. This is useful for the lockless pagecache lookup where | |
888 | * we walk the array with only the RCU lock to protect us, lock the page, | |
889 | * then check that the page hasn't moved since we looked it up. | |
890 | * | |
891 | * The caller guarantees that @xas is still valid. If it may be in an | |
892 | * error or restart state, call xas_load() instead. | |
893 | * | |
894 | * Return: The entry at this location in the xarray. | |
895 | */ | |
896 | static inline void *xas_reload(struct xa_state *xas) | |
897 | { | |
898 | struct xa_node *node = xas->xa_node; | |
899 | ||
900 | if (node) | |
901 | return xa_entry(xas->xa, node, xas->xa_offset); | |
902 | return xa_head(xas->xa); | |
903 | } | |
904 | ||
58d6ea30 MW |
905 | /** |
906 | * xas_set() - Set up XArray operation state for a different index. | |
907 | * @xas: XArray operation state. | |
908 | * @index: New index into the XArray. | |
909 | * | |
910 | * Move the operation state to refer to a different index. This will | |
911 | * have the effect of starting a walk from the top; see xas_next() | |
912 | * to move to an adjacent index. | |
913 | */ | |
914 | static inline void xas_set(struct xa_state *xas, unsigned long index) | |
915 | { | |
916 | xas->xa_index = index; | |
917 | xas->xa_node = XAS_RESTART; | |
918 | } | |
919 | ||
920 | /** | |
921 | * xas_set_order() - Set up XArray operation state for a multislot entry. | |
922 | * @xas: XArray operation state. | |
923 | * @index: Target of the operation. | |
924 | * @order: Entry occupies 2^@order indices. | |
925 | */ | |
926 | static inline void xas_set_order(struct xa_state *xas, unsigned long index, | |
927 | unsigned int order) | |
928 | { | |
929 | #ifdef CONFIG_XARRAY_MULTI | |
930 | xas->xa_index = order < BITS_PER_LONG ? (index >> order) << order : 0; | |
931 | xas->xa_shift = order - (order % XA_CHUNK_SHIFT); | |
932 | xas->xa_sibs = (1 << (order % XA_CHUNK_SHIFT)) - 1; | |
933 | xas->xa_node = XAS_RESTART; | |
934 | #else | |
935 | BUG_ON(order > 0); | |
936 | xas_set(xas, index); | |
937 | #endif | |
938 | } | |
939 | ||
940 | /** | |
941 | * xas_set_update() - Set up XArray operation state for a callback. | |
942 | * @xas: XArray operation state. | |
943 | * @update: Function to call when updating a node. | |
944 | * | |
945 | * The XArray can notify a caller after it has updated an xa_node. | |
946 | * This is advanced functionality and is only needed by the page cache. | |
947 | */ | |
948 | static inline void xas_set_update(struct xa_state *xas, xa_update_node_t update) | |
949 | { | |
950 | xas->xa_update = update; | |
951 | } | |
952 | ||
b803b428 MW |
953 | /** |
954 | * xas_next_entry() - Advance iterator to next present entry. | |
955 | * @xas: XArray operation state. | |
956 | * @max: Highest index to return. | |
957 | * | |
958 | * xas_next_entry() is an inline function to optimise xarray traversal for | |
959 | * speed. It is equivalent to calling xas_find(), and will call xas_find() | |
960 | * for all the hard cases. | |
961 | * | |
962 | * Return: The next present entry after the one currently referred to by @xas. | |
963 | */ | |
964 | static inline void *xas_next_entry(struct xa_state *xas, unsigned long max) | |
965 | { | |
966 | struct xa_node *node = xas->xa_node; | |
967 | void *entry; | |
968 | ||
969 | if (unlikely(xas_not_node(node) || node->shift || | |
970 | xas->xa_offset != (xas->xa_index & XA_CHUNK_MASK))) | |
971 | return xas_find(xas, max); | |
972 | ||
973 | do { | |
974 | if (unlikely(xas->xa_index >= max)) | |
975 | return xas_find(xas, max); | |
976 | if (unlikely(xas->xa_offset == XA_CHUNK_MASK)) | |
977 | return xas_find(xas, max); | |
978 | entry = xa_entry(xas->xa, node, xas->xa_offset + 1); | |
979 | if (unlikely(xa_is_internal(entry))) | |
980 | return xas_find(xas, max); | |
981 | xas->xa_offset++; | |
982 | xas->xa_index++; | |
983 | } while (!entry); | |
984 | ||
985 | return entry; | |
986 | } | |
987 | ||
988 | /* Private */ | |
989 | static inline unsigned int xas_find_chunk(struct xa_state *xas, bool advance, | |
990 | xa_mark_t mark) | |
991 | { | |
992 | unsigned long *addr = xas->xa_node->marks[(__force unsigned)mark]; | |
993 | unsigned int offset = xas->xa_offset; | |
994 | ||
995 | if (advance) | |
996 | offset++; | |
997 | if (XA_CHUNK_SIZE == BITS_PER_LONG) { | |
998 | if (offset < XA_CHUNK_SIZE) { | |
999 | unsigned long data = *addr & (~0UL << offset); | |
1000 | if (data) | |
1001 | return __ffs(data); | |
1002 | } | |
1003 | return XA_CHUNK_SIZE; | |
1004 | } | |
1005 | ||
1006 | return find_next_bit(addr, XA_CHUNK_SIZE, offset); | |
1007 | } | |
1008 | ||
1009 | /** | |
1010 | * xas_next_marked() - Advance iterator to next marked entry. | |
1011 | * @xas: XArray operation state. | |
1012 | * @max: Highest index to return. | |
1013 | * @mark: Mark to search for. | |
1014 | * | |
1015 | * xas_next_marked() is an inline function to optimise xarray traversal for | |
1016 | * speed. It is equivalent to calling xas_find_marked(), and will call | |
1017 | * xas_find_marked() for all the hard cases. | |
1018 | * | |
1019 | * Return: The next marked entry after the one currently referred to by @xas. | |
1020 | */ | |
1021 | static inline void *xas_next_marked(struct xa_state *xas, unsigned long max, | |
1022 | xa_mark_t mark) | |
1023 | { | |
1024 | struct xa_node *node = xas->xa_node; | |
1025 | unsigned int offset; | |
1026 | ||
1027 | if (unlikely(xas_not_node(node) || node->shift)) | |
1028 | return xas_find_marked(xas, max, mark); | |
1029 | offset = xas_find_chunk(xas, true, mark); | |
1030 | xas->xa_offset = offset; | |
1031 | xas->xa_index = (xas->xa_index & ~XA_CHUNK_MASK) + offset; | |
1032 | if (xas->xa_index > max) | |
1033 | return NULL; | |
1034 | if (offset == XA_CHUNK_SIZE) | |
1035 | return xas_find_marked(xas, max, mark); | |
1036 | return xa_entry(xas->xa, node, offset); | |
1037 | } | |
1038 | ||
1039 | /* | |
1040 | * If iterating while holding a lock, drop the lock and reschedule | |
1041 | * every %XA_CHECK_SCHED loops. | |
1042 | */ | |
1043 | enum { | |
1044 | XA_CHECK_SCHED = 4096, | |
1045 | }; | |
1046 | ||
1047 | /** | |
1048 | * xas_for_each() - Iterate over a range of an XArray. | |
1049 | * @xas: XArray operation state. | |
1050 | * @entry: Entry retrieved from the array. | |
1051 | * @max: Maximum index to retrieve from array. | |
1052 | * | |
1053 | * The loop body will be executed for each entry present in the xarray | |
1054 | * between the current xas position and @max. @entry will be set to | |
1055 | * the entry retrieved from the xarray. It is safe to delete entries | |
1056 | * from the array in the loop body. You should hold either the RCU lock | |
1057 | * or the xa_lock while iterating. If you need to drop the lock, call | |
1058 | * xas_pause() first. | |
1059 | */ | |
1060 | #define xas_for_each(xas, entry, max) \ | |
1061 | for (entry = xas_find(xas, max); entry; \ | |
1062 | entry = xas_next_entry(xas, max)) | |
1063 | ||
1064 | /** | |
1065 | * xas_for_each_marked() - Iterate over a range of an XArray. | |
1066 | * @xas: XArray operation state. | |
1067 | * @entry: Entry retrieved from the array. | |
1068 | * @max: Maximum index to retrieve from array. | |
1069 | * @mark: Mark to search for. | |
1070 | * | |
1071 | * The loop body will be executed for each marked entry in the xarray | |
1072 | * between the current xas position and @max. @entry will be set to | |
1073 | * the entry retrieved from the xarray. It is safe to delete entries | |
1074 | * from the array in the loop body. You should hold either the RCU lock | |
1075 | * or the xa_lock while iterating. If you need to drop the lock, call | |
1076 | * xas_pause() first. | |
1077 | */ | |
1078 | #define xas_for_each_marked(xas, entry, max, mark) \ | |
1079 | for (entry = xas_find_marked(xas, max, mark); entry; \ | |
1080 | entry = xas_next_marked(xas, max, mark)) | |
1081 | ||
f6bb2a2c | 1082 | #endif /* _LINUX_XARRAY_H */ |