]>
Commit | Line | Data |
---|---|---|
f8d5d0cc MW |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* | |
3 | * XArray implementation | |
4 | * Copyright (c) 2017 Microsoft Corporation | |
5 | * Author: Matthew Wilcox <willy@infradead.org> | |
6 | */ | |
7 | ||
9b89a035 | 8 | #include <linux/bitmap.h> |
f8d5d0cc | 9 | #include <linux/export.h> |
58d6ea30 MW |
10 | #include <linux/list.h> |
11 | #include <linux/slab.h> | |
f8d5d0cc MW |
12 | #include <linux/xarray.h> |
13 | ||
14 | /* | |
15 | * Coding conventions in this file: | |
16 | * | |
17 | * @xa is used to refer to the entire xarray. | |
18 | * @xas is the 'xarray operation state'. It may be either a pointer to | |
19 | * an xa_state, or an xa_state stored on the stack. This is an unfortunate | |
20 | * ambiguity. | |
21 | * @index is the index of the entry being operated on | |
22 | * @mark is an xa_mark_t; a small number indicating one of the mark bits. | |
23 | * @node refers to an xa_node; usually the primary one being operated on by | |
24 | * this function. | |
25 | * @offset is the index into the slots array inside an xa_node. | |
26 | * @parent refers to the @xa_node closer to the head than @node. | |
27 | * @entry refers to something stored in a slot in the xarray | |
28 | */ | |
29 | ||
58d6ea30 MW |
30 | static inline unsigned int xa_lock_type(const struct xarray *xa) |
31 | { | |
32 | return (__force unsigned int)xa->xa_flags & 3; | |
33 | } | |
34 | ||
35 | static inline void xas_lock_type(struct xa_state *xas, unsigned int lock_type) | |
36 | { | |
37 | if (lock_type == XA_LOCK_IRQ) | |
38 | xas_lock_irq(xas); | |
39 | else if (lock_type == XA_LOCK_BH) | |
40 | xas_lock_bh(xas); | |
41 | else | |
42 | xas_lock(xas); | |
43 | } | |
44 | ||
45 | static inline void xas_unlock_type(struct xa_state *xas, unsigned int lock_type) | |
46 | { | |
47 | if (lock_type == XA_LOCK_IRQ) | |
48 | xas_unlock_irq(xas); | |
49 | else if (lock_type == XA_LOCK_BH) | |
50 | xas_unlock_bh(xas); | |
51 | else | |
52 | xas_unlock(xas); | |
53 | } | |
54 | ||
9b89a035 MW |
55 | static inline void xa_mark_set(struct xarray *xa, xa_mark_t mark) |
56 | { | |
57 | if (!(xa->xa_flags & XA_FLAGS_MARK(mark))) | |
58 | xa->xa_flags |= XA_FLAGS_MARK(mark); | |
59 | } | |
60 | ||
61 | static inline void xa_mark_clear(struct xarray *xa, xa_mark_t mark) | |
62 | { | |
63 | if (xa->xa_flags & XA_FLAGS_MARK(mark)) | |
64 | xa->xa_flags &= ~(XA_FLAGS_MARK(mark)); | |
65 | } | |
66 | ||
67 | static inline unsigned long *node_marks(struct xa_node *node, xa_mark_t mark) | |
68 | { | |
69 | return node->marks[(__force unsigned)mark]; | |
70 | } | |
71 | ||
72 | static inline bool node_get_mark(struct xa_node *node, | |
73 | unsigned int offset, xa_mark_t mark) | |
74 | { | |
75 | return test_bit(offset, node_marks(node, mark)); | |
76 | } | |
77 | ||
78 | /* returns true if the bit was set */ | |
79 | static inline bool node_set_mark(struct xa_node *node, unsigned int offset, | |
80 | xa_mark_t mark) | |
81 | { | |
82 | return __test_and_set_bit(offset, node_marks(node, mark)); | |
83 | } | |
84 | ||
85 | /* returns true if the bit was set */ | |
86 | static inline bool node_clear_mark(struct xa_node *node, unsigned int offset, | |
87 | xa_mark_t mark) | |
88 | { | |
89 | return __test_and_clear_bit(offset, node_marks(node, mark)); | |
90 | } | |
91 | ||
92 | static inline bool node_any_mark(struct xa_node *node, xa_mark_t mark) | |
93 | { | |
94 | return !bitmap_empty(node_marks(node, mark), XA_CHUNK_SIZE); | |
95 | } | |
96 | ||
58d6ea30 MW |
97 | #define mark_inc(mark) do { \ |
98 | mark = (__force xa_mark_t)((__force unsigned)(mark) + 1); \ | |
99 | } while (0) | |
100 | ||
101 | /* | |
102 | * xas_squash_marks() - Merge all marks to the first entry | |
103 | * @xas: Array operation state. | |
104 | * | |
105 | * Set a mark on the first entry if any entry has it set. Clear marks on | |
106 | * all sibling entries. | |
107 | */ | |
108 | static void xas_squash_marks(const struct xa_state *xas) | |
109 | { | |
110 | unsigned int mark = 0; | |
111 | unsigned int limit = xas->xa_offset + xas->xa_sibs + 1; | |
112 | ||
113 | if (!xas->xa_sibs) | |
114 | return; | |
115 | ||
116 | do { | |
117 | unsigned long *marks = xas->xa_node->marks[mark]; | |
118 | if (find_next_bit(marks, limit, xas->xa_offset + 1) == limit) | |
119 | continue; | |
120 | __set_bit(xas->xa_offset, marks); | |
121 | bitmap_clear(marks, xas->xa_offset + 1, xas->xa_sibs); | |
122 | } while (mark++ != (__force unsigned)XA_MARK_MAX); | |
123 | } | |
124 | ||
ad3d6c72 MW |
125 | /* extracts the offset within this node from the index */ |
126 | static unsigned int get_offset(unsigned long index, struct xa_node *node) | |
127 | { | |
128 | return (index >> node->shift) & XA_CHUNK_MASK; | |
129 | } | |
130 | ||
131 | /* move the index either forwards (find) or backwards (sibling slot) */ | |
132 | static void xas_move_index(struct xa_state *xas, unsigned long offset) | |
133 | { | |
134 | unsigned int shift = xas->xa_node->shift; | |
135 | xas->xa_index &= ~XA_CHUNK_MASK << shift; | |
136 | xas->xa_index += offset << shift; | |
137 | } | |
138 | ||
139 | static void *set_bounds(struct xa_state *xas) | |
140 | { | |
141 | xas->xa_node = XAS_BOUNDS; | |
142 | return NULL; | |
143 | } | |
144 | ||
145 | /* | |
146 | * Starts a walk. If the @xas is already valid, we assume that it's on | |
147 | * the right path and just return where we've got to. If we're in an | |
148 | * error state, return NULL. If the index is outside the current scope | |
149 | * of the xarray, return NULL without changing @xas->xa_node. Otherwise | |
150 | * set @xas->xa_node to NULL and return the current head of the array. | |
151 | */ | |
152 | static void *xas_start(struct xa_state *xas) | |
153 | { | |
154 | void *entry; | |
155 | ||
156 | if (xas_valid(xas)) | |
157 | return xas_reload(xas); | |
158 | if (xas_error(xas)) | |
159 | return NULL; | |
160 | ||
161 | entry = xa_head(xas->xa); | |
162 | if (!xa_is_node(entry)) { | |
163 | if (xas->xa_index) | |
164 | return set_bounds(xas); | |
165 | } else { | |
166 | if ((xas->xa_index >> xa_to_node(entry)->shift) > XA_CHUNK_MASK) | |
167 | return set_bounds(xas); | |
168 | } | |
169 | ||
170 | xas->xa_node = NULL; | |
171 | return entry; | |
172 | } | |
173 | ||
174 | static void *xas_descend(struct xa_state *xas, struct xa_node *node) | |
175 | { | |
176 | unsigned int offset = get_offset(xas->xa_index, node); | |
177 | void *entry = xa_entry(xas->xa, node, offset); | |
178 | ||
179 | xas->xa_node = node; | |
180 | if (xa_is_sibling(entry)) { | |
181 | offset = xa_to_sibling(entry); | |
182 | entry = xa_entry(xas->xa, node, offset); | |
183 | } | |
184 | ||
185 | xas->xa_offset = offset; | |
186 | return entry; | |
187 | } | |
188 | ||
189 | /** | |
190 | * xas_load() - Load an entry from the XArray (advanced). | |
191 | * @xas: XArray operation state. | |
192 | * | |
193 | * Usually walks the @xas to the appropriate state to load the entry | |
194 | * stored at xa_index. However, it will do nothing and return %NULL if | |
195 | * @xas is in an error state. xas_load() will never expand the tree. | |
196 | * | |
197 | * If the xa_state is set up to operate on a multi-index entry, xas_load() | |
198 | * may return %NULL or an internal entry, even if there are entries | |
199 | * present within the range specified by @xas. | |
200 | * | |
201 | * Context: Any context. The caller should hold the xa_lock or the RCU lock. | |
202 | * Return: Usually an entry in the XArray, but see description for exceptions. | |
203 | */ | |
204 | void *xas_load(struct xa_state *xas) | |
205 | { | |
206 | void *entry = xas_start(xas); | |
207 | ||
208 | while (xa_is_node(entry)) { | |
209 | struct xa_node *node = xa_to_node(entry); | |
210 | ||
211 | if (xas->xa_shift > node->shift) | |
212 | break; | |
213 | entry = xas_descend(xas, node); | |
214 | } | |
215 | return entry; | |
216 | } | |
217 | EXPORT_SYMBOL_GPL(xas_load); | |
218 | ||
58d6ea30 MW |
219 | /* Move the radix tree node cache here */ |
220 | extern struct kmem_cache *radix_tree_node_cachep; | |
221 | extern void radix_tree_node_rcu_free(struct rcu_head *head); | |
222 | ||
223 | #define XA_RCU_FREE ((struct xarray *)1) | |
224 | ||
225 | static void xa_node_free(struct xa_node *node) | |
226 | { | |
227 | XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); | |
228 | node->array = XA_RCU_FREE; | |
229 | call_rcu(&node->rcu_head, radix_tree_node_rcu_free); | |
230 | } | |
231 | ||
232 | /* | |
233 | * xas_destroy() - Free any resources allocated during the XArray operation. | |
234 | * @xas: XArray operation state. | |
235 | * | |
236 | * This function is now internal-only. | |
237 | */ | |
238 | static void xas_destroy(struct xa_state *xas) | |
239 | { | |
240 | struct xa_node *node = xas->xa_alloc; | |
241 | ||
242 | if (!node) | |
243 | return; | |
244 | XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); | |
245 | kmem_cache_free(radix_tree_node_cachep, node); | |
246 | xas->xa_alloc = NULL; | |
247 | } | |
248 | ||
249 | /** | |
250 | * xas_nomem() - Allocate memory if needed. | |
251 | * @xas: XArray operation state. | |
252 | * @gfp: Memory allocation flags. | |
253 | * | |
254 | * If we need to add new nodes to the XArray, we try to allocate memory | |
255 | * with GFP_NOWAIT while holding the lock, which will usually succeed. | |
256 | * If it fails, @xas is flagged as needing memory to continue. The caller | |
257 | * should drop the lock and call xas_nomem(). If xas_nomem() succeeds, | |
258 | * the caller should retry the operation. | |
259 | * | |
260 | * Forward progress is guaranteed as one node is allocated here and | |
261 | * stored in the xa_state where it will be found by xas_alloc(). More | |
262 | * nodes will likely be found in the slab allocator, but we do not tie | |
263 | * them up here. | |
264 | * | |
265 | * Return: true if memory was needed, and was successfully allocated. | |
266 | */ | |
267 | bool xas_nomem(struct xa_state *xas, gfp_t gfp) | |
268 | { | |
269 | if (xas->xa_node != XA_ERROR(-ENOMEM)) { | |
270 | xas_destroy(xas); | |
271 | return false; | |
272 | } | |
273 | xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); | |
274 | if (!xas->xa_alloc) | |
275 | return false; | |
276 | XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list)); | |
277 | xas->xa_node = XAS_RESTART; | |
278 | return true; | |
279 | } | |
280 | EXPORT_SYMBOL_GPL(xas_nomem); | |
281 | ||
282 | /* | |
283 | * __xas_nomem() - Drop locks and allocate memory if needed. | |
284 | * @xas: XArray operation state. | |
285 | * @gfp: Memory allocation flags. | |
286 | * | |
287 | * Internal variant of xas_nomem(). | |
288 | * | |
289 | * Return: true if memory was needed, and was successfully allocated. | |
290 | */ | |
291 | static bool __xas_nomem(struct xa_state *xas, gfp_t gfp) | |
292 | __must_hold(xas->xa->xa_lock) | |
293 | { | |
294 | unsigned int lock_type = xa_lock_type(xas->xa); | |
295 | ||
296 | if (xas->xa_node != XA_ERROR(-ENOMEM)) { | |
297 | xas_destroy(xas); | |
298 | return false; | |
299 | } | |
300 | if (gfpflags_allow_blocking(gfp)) { | |
301 | xas_unlock_type(xas, lock_type); | |
302 | xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); | |
303 | xas_lock_type(xas, lock_type); | |
304 | } else { | |
305 | xas->xa_alloc = kmem_cache_alloc(radix_tree_node_cachep, gfp); | |
306 | } | |
307 | if (!xas->xa_alloc) | |
308 | return false; | |
309 | XA_NODE_BUG_ON(xas->xa_alloc, !list_empty(&xas->xa_alloc->private_list)); | |
310 | xas->xa_node = XAS_RESTART; | |
311 | return true; | |
312 | } | |
313 | ||
314 | static void xas_update(struct xa_state *xas, struct xa_node *node) | |
315 | { | |
316 | if (xas->xa_update) | |
317 | xas->xa_update(node); | |
318 | else | |
319 | XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); | |
320 | } | |
321 | ||
322 | static void *xas_alloc(struct xa_state *xas, unsigned int shift) | |
323 | { | |
324 | struct xa_node *parent = xas->xa_node; | |
325 | struct xa_node *node = xas->xa_alloc; | |
326 | ||
327 | if (xas_invalid(xas)) | |
328 | return NULL; | |
329 | ||
330 | if (node) { | |
331 | xas->xa_alloc = NULL; | |
332 | } else { | |
333 | node = kmem_cache_alloc(radix_tree_node_cachep, | |
334 | GFP_NOWAIT | __GFP_NOWARN); | |
335 | if (!node) { | |
336 | xas_set_err(xas, -ENOMEM); | |
337 | return NULL; | |
338 | } | |
339 | } | |
340 | ||
341 | if (parent) { | |
342 | node->offset = xas->xa_offset; | |
343 | parent->count++; | |
344 | XA_NODE_BUG_ON(node, parent->count > XA_CHUNK_SIZE); | |
345 | xas_update(xas, parent); | |
346 | } | |
347 | XA_NODE_BUG_ON(node, shift > BITS_PER_LONG); | |
348 | XA_NODE_BUG_ON(node, !list_empty(&node->private_list)); | |
349 | node->shift = shift; | |
350 | node->count = 0; | |
351 | node->nr_values = 0; | |
352 | RCU_INIT_POINTER(node->parent, xas->xa_node); | |
353 | node->array = xas->xa; | |
354 | ||
355 | return node; | |
356 | } | |
357 | ||
358 | /* | |
359 | * Use this to calculate the maximum index that will need to be created | |
360 | * in order to add the entry described by @xas. Because we cannot store a | |
361 | * multiple-index entry at index 0, the calculation is a little more complex | |
362 | * than you might expect. | |
363 | */ | |
364 | static unsigned long xas_max(struct xa_state *xas) | |
365 | { | |
366 | unsigned long max = xas->xa_index; | |
367 | ||
368 | #ifdef CONFIG_XARRAY_MULTI | |
369 | if (xas->xa_shift || xas->xa_sibs) { | |
370 | unsigned long mask; | |
371 | mask = (((xas->xa_sibs + 1UL) << xas->xa_shift) - 1); | |
372 | max |= mask; | |
373 | if (mask == max) | |
374 | max++; | |
375 | } | |
376 | #endif | |
377 | ||
378 | return max; | |
379 | } | |
380 | ||
381 | /* The maximum index that can be contained in the array without expanding it */ | |
382 | static unsigned long max_index(void *entry) | |
383 | { | |
384 | if (!xa_is_node(entry)) | |
385 | return 0; | |
386 | return (XA_CHUNK_SIZE << xa_to_node(entry)->shift) - 1; | |
387 | } | |
388 | ||
389 | static void xas_shrink(struct xa_state *xas) | |
390 | { | |
391 | struct xarray *xa = xas->xa; | |
392 | struct xa_node *node = xas->xa_node; | |
393 | ||
394 | for (;;) { | |
395 | void *entry; | |
396 | ||
397 | XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); | |
398 | if (node->count != 1) | |
399 | break; | |
400 | entry = xa_entry_locked(xa, node, 0); | |
401 | if (!entry) | |
402 | break; | |
403 | if (!xa_is_node(entry) && node->shift) | |
404 | break; | |
405 | xas->xa_node = XAS_BOUNDS; | |
406 | ||
407 | RCU_INIT_POINTER(xa->xa_head, entry); | |
408 | ||
409 | node->count = 0; | |
410 | node->nr_values = 0; | |
411 | if (!xa_is_node(entry)) | |
412 | RCU_INIT_POINTER(node->slots[0], XA_RETRY_ENTRY); | |
413 | xas_update(xas, node); | |
414 | xa_node_free(node); | |
415 | if (!xa_is_node(entry)) | |
416 | break; | |
417 | node = xa_to_node(entry); | |
418 | node->parent = NULL; | |
419 | } | |
420 | } | |
421 | ||
422 | /* | |
423 | * xas_delete_node() - Attempt to delete an xa_node | |
424 | * @xas: Array operation state. | |
425 | * | |
426 | * Attempts to delete the @xas->xa_node. This will fail if xa->node has | |
427 | * a non-zero reference count. | |
428 | */ | |
429 | static void xas_delete_node(struct xa_state *xas) | |
430 | { | |
431 | struct xa_node *node = xas->xa_node; | |
432 | ||
433 | for (;;) { | |
434 | struct xa_node *parent; | |
435 | ||
436 | XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); | |
437 | if (node->count) | |
438 | break; | |
439 | ||
440 | parent = xa_parent_locked(xas->xa, node); | |
441 | xas->xa_node = parent; | |
442 | xas->xa_offset = node->offset; | |
443 | xa_node_free(node); | |
444 | ||
445 | if (!parent) { | |
446 | xas->xa->xa_head = NULL; | |
447 | xas->xa_node = XAS_BOUNDS; | |
448 | return; | |
449 | } | |
450 | ||
451 | parent->slots[xas->xa_offset] = NULL; | |
452 | parent->count--; | |
453 | XA_NODE_BUG_ON(parent, parent->count > XA_CHUNK_SIZE); | |
454 | node = parent; | |
455 | xas_update(xas, node); | |
456 | } | |
457 | ||
458 | if (!node->parent) | |
459 | xas_shrink(xas); | |
460 | } | |
461 | ||
462 | /** | |
463 | * xas_free_nodes() - Free this node and all nodes that it references | |
464 | * @xas: Array operation state. | |
465 | * @top: Node to free | |
466 | * | |
467 | * This node has been removed from the tree. We must now free it and all | |
468 | * of its subnodes. There may be RCU walkers with references into the tree, | |
469 | * so we must replace all entries with retry markers. | |
470 | */ | |
471 | static void xas_free_nodes(struct xa_state *xas, struct xa_node *top) | |
472 | { | |
473 | unsigned int offset = 0; | |
474 | struct xa_node *node = top; | |
475 | ||
476 | for (;;) { | |
477 | void *entry = xa_entry_locked(xas->xa, node, offset); | |
478 | ||
479 | if (xa_is_node(entry)) { | |
480 | node = xa_to_node(entry); | |
481 | offset = 0; | |
482 | continue; | |
483 | } | |
484 | if (entry) | |
485 | RCU_INIT_POINTER(node->slots[offset], XA_RETRY_ENTRY); | |
486 | offset++; | |
487 | while (offset == XA_CHUNK_SIZE) { | |
488 | struct xa_node *parent; | |
489 | ||
490 | parent = xa_parent_locked(xas->xa, node); | |
491 | offset = node->offset + 1; | |
492 | node->count = 0; | |
493 | node->nr_values = 0; | |
494 | xas_update(xas, node); | |
495 | xa_node_free(node); | |
496 | if (node == top) | |
497 | return; | |
498 | node = parent; | |
499 | } | |
500 | } | |
501 | } | |
502 | ||
503 | /* | |
504 | * xas_expand adds nodes to the head of the tree until it has reached | |
505 | * sufficient height to be able to contain @xas->xa_index | |
506 | */ | |
507 | static int xas_expand(struct xa_state *xas, void *head) | |
508 | { | |
509 | struct xarray *xa = xas->xa; | |
510 | struct xa_node *node = NULL; | |
511 | unsigned int shift = 0; | |
512 | unsigned long max = xas_max(xas); | |
513 | ||
514 | if (!head) { | |
515 | if (max == 0) | |
516 | return 0; | |
517 | while ((max >> shift) >= XA_CHUNK_SIZE) | |
518 | shift += XA_CHUNK_SHIFT; | |
519 | return shift + XA_CHUNK_SHIFT; | |
520 | } else if (xa_is_node(head)) { | |
521 | node = xa_to_node(head); | |
522 | shift = node->shift + XA_CHUNK_SHIFT; | |
523 | } | |
524 | xas->xa_node = NULL; | |
525 | ||
526 | while (max > max_index(head)) { | |
527 | xa_mark_t mark = 0; | |
528 | ||
529 | XA_NODE_BUG_ON(node, shift > BITS_PER_LONG); | |
530 | node = xas_alloc(xas, shift); | |
531 | if (!node) | |
532 | return -ENOMEM; | |
533 | ||
534 | node->count = 1; | |
535 | if (xa_is_value(head)) | |
536 | node->nr_values = 1; | |
537 | RCU_INIT_POINTER(node->slots[0], head); | |
538 | ||
539 | /* Propagate the aggregated mark info to the new child */ | |
540 | for (;;) { | |
541 | if (xa_marked(xa, mark)) | |
542 | node_set_mark(node, 0, mark); | |
543 | if (mark == XA_MARK_MAX) | |
544 | break; | |
545 | mark_inc(mark); | |
546 | } | |
547 | ||
548 | /* | |
549 | * Now that the new node is fully initialised, we can add | |
550 | * it to the tree | |
551 | */ | |
552 | if (xa_is_node(head)) { | |
553 | xa_to_node(head)->offset = 0; | |
554 | rcu_assign_pointer(xa_to_node(head)->parent, node); | |
555 | } | |
556 | head = xa_mk_node(node); | |
557 | rcu_assign_pointer(xa->xa_head, head); | |
558 | xas_update(xas, node); | |
559 | ||
560 | shift += XA_CHUNK_SHIFT; | |
561 | } | |
562 | ||
563 | xas->xa_node = node; | |
564 | return shift; | |
565 | } | |
566 | ||
567 | /* | |
568 | * xas_create() - Create a slot to store an entry in. | |
569 | * @xas: XArray operation state. | |
570 | * | |
571 | * Most users will not need to call this function directly, as it is called | |
572 | * by xas_store(). It is useful for doing conditional store operations | |
573 | * (see the xa_cmpxchg() implementation for an example). | |
574 | * | |
575 | * Return: If the slot already existed, returns the contents of this slot. | |
576 | * If the slot was newly created, returns NULL. If it failed to create the | |
577 | * slot, returns NULL and indicates the error in @xas. | |
578 | */ | |
579 | static void *xas_create(struct xa_state *xas) | |
580 | { | |
581 | struct xarray *xa = xas->xa; | |
582 | void *entry; | |
583 | void __rcu **slot; | |
584 | struct xa_node *node = xas->xa_node; | |
585 | int shift; | |
586 | unsigned int order = xas->xa_shift; | |
587 | ||
588 | if (xas_top(node)) { | |
589 | entry = xa_head_locked(xa); | |
590 | xas->xa_node = NULL; | |
591 | shift = xas_expand(xas, entry); | |
592 | if (shift < 0) | |
593 | return NULL; | |
594 | entry = xa_head_locked(xa); | |
595 | slot = &xa->xa_head; | |
596 | } else if (xas_error(xas)) { | |
597 | return NULL; | |
598 | } else if (node) { | |
599 | unsigned int offset = xas->xa_offset; | |
600 | ||
601 | shift = node->shift; | |
602 | entry = xa_entry_locked(xa, node, offset); | |
603 | slot = &node->slots[offset]; | |
604 | } else { | |
605 | shift = 0; | |
606 | entry = xa_head_locked(xa); | |
607 | slot = &xa->xa_head; | |
608 | } | |
609 | ||
610 | while (shift > order) { | |
611 | shift -= XA_CHUNK_SHIFT; | |
612 | if (!entry) { | |
613 | node = xas_alloc(xas, shift); | |
614 | if (!node) | |
615 | break; | |
616 | rcu_assign_pointer(*slot, xa_mk_node(node)); | |
617 | } else if (xa_is_node(entry)) { | |
618 | node = xa_to_node(entry); | |
619 | } else { | |
620 | break; | |
621 | } | |
622 | entry = xas_descend(xas, node); | |
623 | slot = &node->slots[xas->xa_offset]; | |
624 | } | |
625 | ||
626 | return entry; | |
627 | } | |
628 | ||
629 | static void update_node(struct xa_state *xas, struct xa_node *node, | |
630 | int count, int values) | |
631 | { | |
632 | if (!node || (!count && !values)) | |
633 | return; | |
634 | ||
635 | node->count += count; | |
636 | node->nr_values += values; | |
637 | XA_NODE_BUG_ON(node, node->count > XA_CHUNK_SIZE); | |
638 | XA_NODE_BUG_ON(node, node->nr_values > XA_CHUNK_SIZE); | |
639 | xas_update(xas, node); | |
640 | if (count < 0) | |
641 | xas_delete_node(xas); | |
642 | } | |
643 | ||
644 | /** | |
645 | * xas_store() - Store this entry in the XArray. | |
646 | * @xas: XArray operation state. | |
647 | * @entry: New entry. | |
648 | * | |
649 | * If @xas is operating on a multi-index entry, the entry returned by this | |
650 | * function is essentially meaningless (it may be an internal entry or it | |
651 | * may be %NULL, even if there are non-NULL entries at some of the indices | |
652 | * covered by the range). This is not a problem for any current users, | |
653 | * and can be changed if needed. | |
654 | * | |
655 | * Return: The old entry at this index. | |
656 | */ | |
657 | void *xas_store(struct xa_state *xas, void *entry) | |
658 | { | |
659 | struct xa_node *node; | |
660 | void __rcu **slot = &xas->xa->xa_head; | |
661 | unsigned int offset, max; | |
662 | int count = 0; | |
663 | int values = 0; | |
664 | void *first, *next; | |
665 | bool value = xa_is_value(entry); | |
666 | ||
667 | if (entry) | |
668 | first = xas_create(xas); | |
669 | else | |
670 | first = xas_load(xas); | |
671 | ||
672 | if (xas_invalid(xas)) | |
673 | return first; | |
674 | node = xas->xa_node; | |
675 | if (node && (xas->xa_shift < node->shift)) | |
676 | xas->xa_sibs = 0; | |
677 | if ((first == entry) && !xas->xa_sibs) | |
678 | return first; | |
679 | ||
680 | next = first; | |
681 | offset = xas->xa_offset; | |
682 | max = xas->xa_offset + xas->xa_sibs; | |
683 | if (node) { | |
684 | slot = &node->slots[offset]; | |
685 | if (xas->xa_sibs) | |
686 | xas_squash_marks(xas); | |
687 | } | |
688 | if (!entry) | |
689 | xas_init_marks(xas); | |
690 | ||
691 | for (;;) { | |
692 | /* | |
693 | * Must clear the marks before setting the entry to NULL, | |
694 | * otherwise xas_for_each_marked may find a NULL entry and | |
695 | * stop early. rcu_assign_pointer contains a release barrier | |
696 | * so the mark clearing will appear to happen before the | |
697 | * entry is set to NULL. | |
698 | */ | |
699 | rcu_assign_pointer(*slot, entry); | |
700 | if (xa_is_node(next)) | |
701 | xas_free_nodes(xas, xa_to_node(next)); | |
702 | if (!node) | |
703 | break; | |
704 | count += !next - !entry; | |
705 | values += !xa_is_value(first) - !value; | |
706 | if (entry) { | |
707 | if (offset == max) | |
708 | break; | |
709 | if (!xa_is_sibling(entry)) | |
710 | entry = xa_mk_sibling(xas->xa_offset); | |
711 | } else { | |
712 | if (offset == XA_CHUNK_MASK) | |
713 | break; | |
714 | } | |
715 | next = xa_entry_locked(xas->xa, node, ++offset); | |
716 | if (!xa_is_sibling(next)) { | |
717 | if (!entry && (offset > max)) | |
718 | break; | |
719 | first = next; | |
720 | } | |
721 | slot++; | |
722 | } | |
723 | ||
724 | update_node(xas, node, count, values); | |
725 | return first; | |
726 | } | |
727 | EXPORT_SYMBOL_GPL(xas_store); | |
728 | ||
9b89a035 MW |
729 | /** |
730 | * xas_get_mark() - Returns the state of this mark. | |
731 | * @xas: XArray operation state. | |
732 | * @mark: Mark number. | |
733 | * | |
734 | * Return: true if the mark is set, false if the mark is clear or @xas | |
735 | * is in an error state. | |
736 | */ | |
737 | bool xas_get_mark(const struct xa_state *xas, xa_mark_t mark) | |
738 | { | |
739 | if (xas_invalid(xas)) | |
740 | return false; | |
741 | if (!xas->xa_node) | |
742 | return xa_marked(xas->xa, mark); | |
743 | return node_get_mark(xas->xa_node, xas->xa_offset, mark); | |
744 | } | |
745 | EXPORT_SYMBOL_GPL(xas_get_mark); | |
746 | ||
747 | /** | |
748 | * xas_set_mark() - Sets the mark on this entry and its parents. | |
749 | * @xas: XArray operation state. | |
750 | * @mark: Mark number. | |
751 | * | |
752 | * Sets the specified mark on this entry, and walks up the tree setting it | |
753 | * on all the ancestor entries. Does nothing if @xas has not been walked to | |
754 | * an entry, or is in an error state. | |
755 | */ | |
756 | void xas_set_mark(const struct xa_state *xas, xa_mark_t mark) | |
757 | { | |
758 | struct xa_node *node = xas->xa_node; | |
759 | unsigned int offset = xas->xa_offset; | |
760 | ||
761 | if (xas_invalid(xas)) | |
762 | return; | |
763 | ||
764 | while (node) { | |
765 | if (node_set_mark(node, offset, mark)) | |
766 | return; | |
767 | offset = node->offset; | |
768 | node = xa_parent_locked(xas->xa, node); | |
769 | } | |
770 | ||
771 | if (!xa_marked(xas->xa, mark)) | |
772 | xa_mark_set(xas->xa, mark); | |
773 | } | |
774 | EXPORT_SYMBOL_GPL(xas_set_mark); | |
775 | ||
776 | /** | |
777 | * xas_clear_mark() - Clears the mark on this entry and its parents. | |
778 | * @xas: XArray operation state. | |
779 | * @mark: Mark number. | |
780 | * | |
781 | * Clears the specified mark on this entry, and walks back to the head | |
782 | * attempting to clear it on all the ancestor entries. Does nothing if | |
783 | * @xas has not been walked to an entry, or is in an error state. | |
784 | */ | |
785 | void xas_clear_mark(const struct xa_state *xas, xa_mark_t mark) | |
786 | { | |
787 | struct xa_node *node = xas->xa_node; | |
788 | unsigned int offset = xas->xa_offset; | |
789 | ||
790 | if (xas_invalid(xas)) | |
791 | return; | |
792 | ||
793 | while (node) { | |
794 | if (!node_clear_mark(node, offset, mark)) | |
795 | return; | |
796 | if (node_any_mark(node, mark)) | |
797 | return; | |
798 | ||
799 | offset = node->offset; | |
800 | node = xa_parent_locked(xas->xa, node); | |
801 | } | |
802 | ||
803 | if (xa_marked(xas->xa, mark)) | |
804 | xa_mark_clear(xas->xa, mark); | |
805 | } | |
806 | EXPORT_SYMBOL_GPL(xas_clear_mark); | |
807 | ||
58d6ea30 MW |
808 | /** |
809 | * xas_init_marks() - Initialise all marks for the entry | |
810 | * @xas: Array operations state. | |
811 | * | |
812 | * Initialise all marks for the entry specified by @xas. If we're tracking | |
813 | * free entries with a mark, we need to set it on all entries. All other | |
814 | * marks are cleared. | |
815 | * | |
816 | * This implementation is not as efficient as it could be; we may walk | |
817 | * up the tree multiple times. | |
818 | */ | |
819 | void xas_init_marks(const struct xa_state *xas) | |
820 | { | |
821 | xa_mark_t mark = 0; | |
822 | ||
823 | for (;;) { | |
824 | xas_clear_mark(xas, mark); | |
825 | if (mark == XA_MARK_MAX) | |
826 | break; | |
827 | mark_inc(mark); | |
828 | } | |
829 | } | |
830 | EXPORT_SYMBOL_GPL(xas_init_marks); | |
831 | ||
f8d5d0cc MW |
832 | /** |
833 | * xa_init_flags() - Initialise an empty XArray with flags. | |
834 | * @xa: XArray. | |
835 | * @flags: XA_FLAG values. | |
836 | * | |
837 | * If you need to initialise an XArray with special flags (eg you need | |
838 | * to take the lock from interrupt context), use this function instead | |
839 | * of xa_init(). | |
840 | * | |
841 | * Context: Any context. | |
842 | */ | |
843 | void xa_init_flags(struct xarray *xa, gfp_t flags) | |
844 | { | |
58d6ea30 MW |
845 | unsigned int lock_type; |
846 | static struct lock_class_key xa_lock_irq; | |
847 | static struct lock_class_key xa_lock_bh; | |
848 | ||
f8d5d0cc MW |
849 | spin_lock_init(&xa->xa_lock); |
850 | xa->xa_flags = flags; | |
851 | xa->xa_head = NULL; | |
58d6ea30 MW |
852 | |
853 | lock_type = xa_lock_type(xa); | |
854 | if (lock_type == XA_LOCK_IRQ) | |
855 | lockdep_set_class(&xa->xa_lock, &xa_lock_irq); | |
856 | else if (lock_type == XA_LOCK_BH) | |
857 | lockdep_set_class(&xa->xa_lock, &xa_lock_bh); | |
f8d5d0cc MW |
858 | } |
859 | EXPORT_SYMBOL(xa_init_flags); | |
ad3d6c72 MW |
860 | |
861 | /** | |
862 | * xa_load() - Load an entry from an XArray. | |
863 | * @xa: XArray. | |
864 | * @index: index into array. | |
865 | * | |
866 | * Context: Any context. Takes and releases the RCU lock. | |
867 | * Return: The entry at @index in @xa. | |
868 | */ | |
869 | void *xa_load(struct xarray *xa, unsigned long index) | |
870 | { | |
871 | XA_STATE(xas, xa, index); | |
872 | void *entry; | |
873 | ||
874 | rcu_read_lock(); | |
875 | do { | |
876 | entry = xas_load(&xas); | |
877 | } while (xas_retry(&xas, entry)); | |
878 | rcu_read_unlock(); | |
879 | ||
880 | return entry; | |
881 | } | |
882 | EXPORT_SYMBOL(xa_load); | |
883 | ||
58d6ea30 MW |
884 | static void *xas_result(struct xa_state *xas, void *curr) |
885 | { | |
886 | XA_NODE_BUG_ON(xas->xa_node, xa_is_internal(curr)); | |
887 | if (xas_error(xas)) | |
888 | curr = xas->xa_node; | |
889 | return curr; | |
890 | } | |
891 | ||
892 | /** | |
893 | * __xa_erase() - Erase this entry from the XArray while locked. | |
894 | * @xa: XArray. | |
895 | * @index: Index into array. | |
896 | * | |
897 | * If the entry at this index is a multi-index entry then all indices will | |
898 | * be erased, and the entry will no longer be a multi-index entry. | |
899 | * This function expects the xa_lock to be held on entry. | |
900 | * | |
901 | * Context: Any context. Expects xa_lock to be held on entry. May | |
902 | * release and reacquire xa_lock if @gfp flags permit. | |
903 | * Return: The old entry at this index. | |
904 | */ | |
905 | void *__xa_erase(struct xarray *xa, unsigned long index) | |
906 | { | |
907 | XA_STATE(xas, xa, index); | |
908 | return xas_result(&xas, xas_store(&xas, NULL)); | |
909 | } | |
910 | EXPORT_SYMBOL_GPL(__xa_erase); | |
911 | ||
912 | /** | |
913 | * xa_store() - Store this entry in the XArray. | |
914 | * @xa: XArray. | |
915 | * @index: Index into array. | |
916 | * @entry: New entry. | |
917 | * @gfp: Memory allocation flags. | |
918 | * | |
919 | * After this function returns, loads from this index will return @entry. | |
920 | * Storing into an existing multislot entry updates the entry of every index. | |
921 | * The marks associated with @index are unaffected unless @entry is %NULL. | |
922 | * | |
923 | * Context: Process context. Takes and releases the xa_lock. May sleep | |
924 | * if the @gfp flags permit. | |
925 | * Return: The old entry at this index on success, xa_err(-EINVAL) if @entry | |
926 | * cannot be stored in an XArray, or xa_err(-ENOMEM) if memory allocation | |
927 | * failed. | |
928 | */ | |
929 | void *xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) | |
930 | { | |
931 | XA_STATE(xas, xa, index); | |
932 | void *curr; | |
933 | ||
934 | if (WARN_ON_ONCE(xa_is_internal(entry))) | |
935 | return XA_ERROR(-EINVAL); | |
936 | ||
937 | do { | |
938 | xas_lock(&xas); | |
939 | curr = xas_store(&xas, entry); | |
940 | xas_unlock(&xas); | |
941 | } while (xas_nomem(&xas, gfp)); | |
942 | ||
943 | return xas_result(&xas, curr); | |
944 | } | |
945 | EXPORT_SYMBOL(xa_store); | |
946 | ||
947 | /** | |
948 | * __xa_store() - Store this entry in the XArray. | |
949 | * @xa: XArray. | |
950 | * @index: Index into array. | |
951 | * @entry: New entry. | |
952 | * @gfp: Memory allocation flags. | |
953 | * | |
954 | * You must already be holding the xa_lock when calling this function. | |
955 | * It will drop the lock if needed to allocate memory, and then reacquire | |
956 | * it afterwards. | |
957 | * | |
958 | * Context: Any context. Expects xa_lock to be held on entry. May | |
959 | * release and reacquire xa_lock if @gfp flags permit. | |
960 | * Return: The old entry at this index or xa_err() if an error happened. | |
961 | */ | |
962 | void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) | |
963 | { | |
964 | XA_STATE(xas, xa, index); | |
965 | void *curr; | |
966 | ||
967 | if (WARN_ON_ONCE(xa_is_internal(entry))) | |
968 | return XA_ERROR(-EINVAL); | |
969 | ||
970 | do { | |
971 | curr = xas_store(&xas, entry); | |
972 | } while (__xas_nomem(&xas, gfp)); | |
973 | ||
974 | return xas_result(&xas, curr); | |
975 | } | |
976 | EXPORT_SYMBOL(__xa_store); | |
977 | ||
41aec91f MW |
978 | /** |
979 | * xa_cmpxchg() - Conditionally replace an entry in the XArray. | |
980 | * @xa: XArray. | |
981 | * @index: Index into array. | |
982 | * @old: Old value to test against. | |
983 | * @entry: New value to place in array. | |
984 | * @gfp: Memory allocation flags. | |
985 | * | |
986 | * If the entry at @index is the same as @old, replace it with @entry. | |
987 | * If the return value is equal to @old, then the exchange was successful. | |
988 | * | |
989 | * Context: Process context. Takes and releases the xa_lock. May sleep | |
990 | * if the @gfp flags permit. | |
991 | * Return: The old value at this index or xa_err() if an error happened. | |
992 | */ | |
993 | void *xa_cmpxchg(struct xarray *xa, unsigned long index, | |
994 | void *old, void *entry, gfp_t gfp) | |
995 | { | |
996 | XA_STATE(xas, xa, index); | |
997 | void *curr; | |
998 | ||
999 | if (WARN_ON_ONCE(xa_is_internal(entry))) | |
1000 | return XA_ERROR(-EINVAL); | |
1001 | ||
1002 | do { | |
1003 | xas_lock(&xas); | |
1004 | curr = xas_load(&xas); | |
1005 | if (curr == old) | |
1006 | xas_store(&xas, entry); | |
1007 | xas_unlock(&xas); | |
1008 | } while (xas_nomem(&xas, gfp)); | |
1009 | ||
1010 | return xas_result(&xas, curr); | |
1011 | } | |
1012 | EXPORT_SYMBOL(xa_cmpxchg); | |
1013 | ||
1014 | /** | |
1015 | * __xa_cmpxchg() - Store this entry in the XArray. | |
1016 | * @xa: XArray. | |
1017 | * @index: Index into array. | |
1018 | * @old: Old value to test against. | |
1019 | * @entry: New entry. | |
1020 | * @gfp: Memory allocation flags. | |
1021 | * | |
1022 | * You must already be holding the xa_lock when calling this function. | |
1023 | * It will drop the lock if needed to allocate memory, and then reacquire | |
1024 | * it afterwards. | |
1025 | * | |
1026 | * Context: Any context. Expects xa_lock to be held on entry. May | |
1027 | * release and reacquire xa_lock if @gfp flags permit. | |
1028 | * Return: The old entry at this index or xa_err() if an error happened. | |
1029 | */ | |
1030 | void *__xa_cmpxchg(struct xarray *xa, unsigned long index, | |
1031 | void *old, void *entry, gfp_t gfp) | |
1032 | { | |
1033 | XA_STATE(xas, xa, index); | |
1034 | void *curr; | |
1035 | ||
1036 | if (WARN_ON_ONCE(xa_is_internal(entry))) | |
1037 | return XA_ERROR(-EINVAL); | |
1038 | ||
1039 | do { | |
1040 | curr = xas_load(&xas); | |
1041 | if (curr == old) | |
1042 | xas_store(&xas, entry); | |
1043 | } while (__xas_nomem(&xas, gfp)); | |
1044 | ||
1045 | return xas_result(&xas, curr); | |
1046 | } | |
1047 | EXPORT_SYMBOL(__xa_cmpxchg); | |
1048 | ||
9b89a035 MW |
1049 | /** |
1050 | * __xa_set_mark() - Set this mark on this entry while locked. | |
1051 | * @xa: XArray. | |
1052 | * @index: Index of entry. | |
1053 | * @mark: Mark number. | |
1054 | * | |
1055 | * Attempting to set a mark on a NULL entry does not succeed. | |
1056 | * | |
1057 | * Context: Any context. Expects xa_lock to be held on entry. | |
1058 | */ | |
1059 | void __xa_set_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) | |
1060 | { | |
1061 | XA_STATE(xas, xa, index); | |
1062 | void *entry = xas_load(&xas); | |
1063 | ||
1064 | if (entry) | |
1065 | xas_set_mark(&xas, mark); | |
1066 | } | |
1067 | EXPORT_SYMBOL_GPL(__xa_set_mark); | |
1068 | ||
1069 | /** | |
1070 | * __xa_clear_mark() - Clear this mark on this entry while locked. | |
1071 | * @xa: XArray. | |
1072 | * @index: Index of entry. | |
1073 | * @mark: Mark number. | |
1074 | * | |
1075 | * Context: Any context. Expects xa_lock to be held on entry. | |
1076 | */ | |
1077 | void __xa_clear_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) | |
1078 | { | |
1079 | XA_STATE(xas, xa, index); | |
1080 | void *entry = xas_load(&xas); | |
1081 | ||
1082 | if (entry) | |
1083 | xas_clear_mark(&xas, mark); | |
1084 | } | |
1085 | EXPORT_SYMBOL_GPL(__xa_clear_mark); | |
1086 | ||
1087 | /** | |
1088 | * xa_get_mark() - Inquire whether this mark is set on this entry. | |
1089 | * @xa: XArray. | |
1090 | * @index: Index of entry. | |
1091 | * @mark: Mark number. | |
1092 | * | |
1093 | * This function uses the RCU read lock, so the result may be out of date | |
1094 | * by the time it returns. If you need the result to be stable, use a lock. | |
1095 | * | |
1096 | * Context: Any context. Takes and releases the RCU lock. | |
1097 | * Return: True if the entry at @index has this mark set, false if it doesn't. | |
1098 | */ | |
1099 | bool xa_get_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) | |
1100 | { | |
1101 | XA_STATE(xas, xa, index); | |
1102 | void *entry; | |
1103 | ||
1104 | rcu_read_lock(); | |
1105 | entry = xas_start(&xas); | |
1106 | while (xas_get_mark(&xas, mark)) { | |
1107 | if (!xa_is_node(entry)) | |
1108 | goto found; | |
1109 | entry = xas_descend(&xas, xa_to_node(entry)); | |
1110 | } | |
1111 | rcu_read_unlock(); | |
1112 | return false; | |
1113 | found: | |
1114 | rcu_read_unlock(); | |
1115 | return true; | |
1116 | } | |
1117 | EXPORT_SYMBOL(xa_get_mark); | |
1118 | ||
1119 | /** | |
1120 | * xa_set_mark() - Set this mark on this entry. | |
1121 | * @xa: XArray. | |
1122 | * @index: Index of entry. | |
1123 | * @mark: Mark number. | |
1124 | * | |
1125 | * Attempting to set a mark on a NULL entry does not succeed. | |
1126 | * | |
1127 | * Context: Process context. Takes and releases the xa_lock. | |
1128 | */ | |
1129 | void xa_set_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) | |
1130 | { | |
1131 | xa_lock(xa); | |
1132 | __xa_set_mark(xa, index, mark); | |
1133 | xa_unlock(xa); | |
1134 | } | |
1135 | EXPORT_SYMBOL(xa_set_mark); | |
1136 | ||
1137 | /** | |
1138 | * xa_clear_mark() - Clear this mark on this entry. | |
1139 | * @xa: XArray. | |
1140 | * @index: Index of entry. | |
1141 | * @mark: Mark number. | |
1142 | * | |
1143 | * Clearing a mark always succeeds. | |
1144 | * | |
1145 | * Context: Process context. Takes and releases the xa_lock. | |
1146 | */ | |
1147 | void xa_clear_mark(struct xarray *xa, unsigned long index, xa_mark_t mark) | |
1148 | { | |
1149 | xa_lock(xa); | |
1150 | __xa_clear_mark(xa, index, mark); | |
1151 | xa_unlock(xa); | |
1152 | } | |
1153 | EXPORT_SYMBOL(xa_clear_mark); | |
1154 | ||
ad3d6c72 MW |
1155 | #ifdef XA_DEBUG |
1156 | void xa_dump_node(const struct xa_node *node) | |
1157 | { | |
1158 | unsigned i, j; | |
1159 | ||
1160 | if (!node) | |
1161 | return; | |
1162 | if ((unsigned long)node & 3) { | |
1163 | pr_cont("node %px\n", node); | |
1164 | return; | |
1165 | } | |
1166 | ||
1167 | pr_cont("node %px %s %d parent %px shift %d count %d values %d " | |
1168 | "array %px list %px %px marks", | |
1169 | node, node->parent ? "offset" : "max", node->offset, | |
1170 | node->parent, node->shift, node->count, node->nr_values, | |
1171 | node->array, node->private_list.prev, node->private_list.next); | |
1172 | for (i = 0; i < XA_MAX_MARKS; i++) | |
1173 | for (j = 0; j < XA_MARK_LONGS; j++) | |
1174 | pr_cont(" %lx", node->marks[i][j]); | |
1175 | pr_cont("\n"); | |
1176 | } | |
1177 | ||
1178 | void xa_dump_index(unsigned long index, unsigned int shift) | |
1179 | { | |
1180 | if (!shift) | |
1181 | pr_info("%lu: ", index); | |
1182 | else if (shift >= BITS_PER_LONG) | |
1183 | pr_info("0-%lu: ", ~0UL); | |
1184 | else | |
1185 | pr_info("%lu-%lu: ", index, index | ((1UL << shift) - 1)); | |
1186 | } | |
1187 | ||
1188 | void xa_dump_entry(const void *entry, unsigned long index, unsigned long shift) | |
1189 | { | |
1190 | if (!entry) | |
1191 | return; | |
1192 | ||
1193 | xa_dump_index(index, shift); | |
1194 | ||
1195 | if (xa_is_node(entry)) { | |
1196 | if (shift == 0) { | |
1197 | pr_cont("%px\n", entry); | |
1198 | } else { | |
1199 | unsigned long i; | |
1200 | struct xa_node *node = xa_to_node(entry); | |
1201 | xa_dump_node(node); | |
1202 | for (i = 0; i < XA_CHUNK_SIZE; i++) | |
1203 | xa_dump_entry(node->slots[i], | |
1204 | index + (i << node->shift), node->shift); | |
1205 | } | |
1206 | } else if (xa_is_value(entry)) | |
1207 | pr_cont("value %ld (0x%lx) [%px]\n", xa_to_value(entry), | |
1208 | xa_to_value(entry), entry); | |
1209 | else if (!xa_is_internal(entry)) | |
1210 | pr_cont("%px\n", entry); | |
1211 | else if (xa_is_retry(entry)) | |
1212 | pr_cont("retry (%ld)\n", xa_to_internal(entry)); | |
1213 | else if (xa_is_sibling(entry)) | |
1214 | pr_cont("sibling (slot %ld)\n", xa_to_sibling(entry)); | |
1215 | else | |
1216 | pr_cont("UNKNOWN ENTRY (%px)\n", entry); | |
1217 | } | |
1218 | ||
1219 | void xa_dump(const struct xarray *xa) | |
1220 | { | |
1221 | void *entry = xa->xa_head; | |
1222 | unsigned int shift = 0; | |
1223 | ||
1224 | pr_info("xarray: %px head %px flags %x marks %d %d %d\n", xa, entry, | |
9b89a035 MW |
1225 | xa->xa_flags, xa_marked(xa, XA_MARK_0), |
1226 | xa_marked(xa, XA_MARK_1), xa_marked(xa, XA_MARK_2)); | |
ad3d6c72 MW |
1227 | if (xa_is_node(entry)) |
1228 | shift = xa_to_node(entry)->shift + XA_CHUNK_SHIFT; | |
1229 | xa_dump_entry(entry, 0, shift); | |
1230 | } | |
1231 | #endif |