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-rw-r--r--lib/Makefile3
-rw-r--r--lib/idr.c1242
-rw-r--r--lib/radix-tree.c761
3 files changed, 819 insertions, 1187 deletions
diff --git a/lib/Makefile b/lib/Makefile
index 469b2392893a..320ac46a8725 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -25,6 +25,9 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
25 earlycpio.o seq_buf.o siphash.o \ 25 earlycpio.o seq_buf.o siphash.o \
26 nmi_backtrace.o nodemask.o win_minmax.o 26 nmi_backtrace.o nodemask.o win_minmax.o
27 27
28CFLAGS_radix-tree.o += -DCONFIG_SPARSE_RCU_POINTER
29CFLAGS_idr.o += -DCONFIG_SPARSE_RCU_POINTER
30
28lib-$(CONFIG_MMU) += ioremap.o 31lib-$(CONFIG_MMU) += ioremap.o
29lib-$(CONFIG_SMP) += cpumask.o 32lib-$(CONFIG_SMP) += cpumask.o
30lib-$(CONFIG_DMA_NOOP_OPS) += dma-noop.o 33lib-$(CONFIG_DMA_NOOP_OPS) += dma-noop.o
diff --git a/lib/idr.c b/lib/idr.c
index 52d2979a05e8..b13682bb0a1c 100644
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -1,1068 +1,409 @@
1/* 1#include <linux/bitmap.h>
2 * 2002-10-18 written by Jim Houston jim.houston@ccur.com
3 * Copyright (C) 2002 by Concurrent Computer Corporation
4 * Distributed under the GNU GPL license version 2.
5 *
6 * Modified by George Anzinger to reuse immediately and to use
7 * find bit instructions. Also removed _irq on spinlocks.
8 *
9 * Modified by Nadia Derbey to make it RCU safe.
10 *
11 * Small id to pointer translation service.
12 *
13 * It uses a radix tree like structure as a sparse array indexed
14 * by the id to obtain the pointer. The bitmap makes allocating
15 * a new id quick.
16 *
17 * You call it to allocate an id (an int) an associate with that id a
18 * pointer or what ever, we treat it as a (void *). You can pass this
19 * id to a user for him to pass back at a later time. You then pass
20 * that id to this code and it returns your pointer.
21 */
22
23#ifndef TEST // to test in user space...
24#include <linux/slab.h>
25#include <linux/init.h>
26#include <linux/export.h> 2#include <linux/export.h>
27#endif
28#include <linux/err.h>
29#include <linux/string.h>
30#include <linux/idr.h> 3#include <linux/idr.h>
4#include <linux/slab.h>
31#include <linux/spinlock.h> 5#include <linux/spinlock.h>
32#include <linux/percpu.h>
33
34#define MAX_IDR_SHIFT (sizeof(int) * 8 - 1)
35#define MAX_IDR_BIT (1U << MAX_IDR_SHIFT)
36
37/* Leave the possibility of an incomplete final layer */
38#define MAX_IDR_LEVEL ((MAX_IDR_SHIFT + IDR_BITS - 1) / IDR_BITS)
39 6
40/* Number of id_layer structs to leave in free list */ 7DEFINE_PER_CPU(struct ida_bitmap *, ida_bitmap);
41#define MAX_IDR_FREE (MAX_IDR_LEVEL * 2)
42
43static struct kmem_cache *idr_layer_cache;
44static DEFINE_PER_CPU(struct idr_layer *, idr_preload_head);
45static DEFINE_PER_CPU(int, idr_preload_cnt);
46static DEFINE_SPINLOCK(simple_ida_lock); 8static DEFINE_SPINLOCK(simple_ida_lock);
47 9
48/* the maximum ID which can be allocated given idr->layers */
49static int idr_max(int layers)
50{
51 int bits = min_t(int, layers * IDR_BITS, MAX_IDR_SHIFT);
52
53 return (1 << bits) - 1;
54}
55
56/*
57 * Prefix mask for an idr_layer at @layer. For layer 0, the prefix mask is
58 * all bits except for the lower IDR_BITS. For layer 1, 2 * IDR_BITS, and
59 * so on.
60 */
61static int idr_layer_prefix_mask(int layer)
62{
63 return ~idr_max(layer + 1);
64}
65
66static struct idr_layer *get_from_free_list(struct idr *idp)
67{
68 struct idr_layer *p;
69 unsigned long flags;
70
71 spin_lock_irqsave(&idp->lock, flags);
72 if ((p = idp->id_free)) {
73 idp->id_free = p->ary[0];
74 idp->id_free_cnt--;
75 p->ary[0] = NULL;
76 }
77 spin_unlock_irqrestore(&idp->lock, flags);
78 return(p);
79}
80
81/** 10/**
82 * idr_layer_alloc - allocate a new idr_layer 11 * idr_alloc - allocate an id
83 * @gfp_mask: allocation mask 12 * @idr: idr handle
84 * @layer_idr: optional idr to allocate from
85 *
86 * If @layer_idr is %NULL, directly allocate one using @gfp_mask or fetch
87 * one from the per-cpu preload buffer. If @layer_idr is not %NULL, fetch
88 * an idr_layer from @idr->id_free.
89 *
90 * @layer_idr is to maintain backward compatibility with the old alloc
91 * interface - idr_pre_get() and idr_get_new*() - and will be removed
92 * together with per-pool preload buffer.
93 */
94static struct idr_layer *idr_layer_alloc(gfp_t gfp_mask, struct idr *layer_idr)
95{
96 struct idr_layer *new;
97
98 /* this is the old path, bypass to get_from_free_list() */
99 if (layer_idr)
100 return get_from_free_list(layer_idr);
101
102 /*
103 * Try to allocate directly from kmem_cache. We want to try this
104 * before preload buffer; otherwise, non-preloading idr_alloc()
105 * users will end up taking advantage of preloading ones. As the
106 * following is allowed to fail for preloaded cases, suppress
107 * warning this time.
108 */
109 new = kmem_cache_zalloc(idr_layer_cache, gfp_mask | __GFP_NOWARN);
110 if (new)
111 return new;
112
113 /*
114 * Try to fetch one from the per-cpu preload buffer if in process
115 * context. See idr_preload() for details.
116 */
117 if (!in_interrupt()) {
118 preempt_disable();
119 new = __this_cpu_read(idr_preload_head);
120 if (new) {
121 __this_cpu_write(idr_preload_head, new->ary[0]);
122 __this_cpu_dec(idr_preload_cnt);
123 new->ary[0] = NULL;
124 }
125 preempt_enable();
126 if (new)
127 return new;
128 }
129
130 /*
131 * Both failed. Try kmem_cache again w/o adding __GFP_NOWARN so
132 * that memory allocation failure warning is printed as intended.
133 */
134 return kmem_cache_zalloc(idr_layer_cache, gfp_mask);
135}
136
137static void idr_layer_rcu_free(struct rcu_head *head)
138{
139 struct idr_layer *layer;
140
141 layer = container_of(head, struct idr_layer, rcu_head);
142 kmem_cache_free(idr_layer_cache, layer);
143}
144
145static inline void free_layer(struct idr *idr, struct idr_layer *p)
146{
147 if (idr->hint == p)
148 RCU_INIT_POINTER(idr->hint, NULL);
149 call_rcu(&p->rcu_head, idr_layer_rcu_free);
150}
151
152/* only called when idp->lock is held */
153static void __move_to_free_list(struct idr *idp, struct idr_layer *p)
154{
155 p->ary[0] = idp->id_free;
156 idp->id_free = p;
157 idp->id_free_cnt++;
158}
159
160static void move_to_free_list(struct idr *idp, struct idr_layer *p)
161{
162 unsigned long flags;
163
164 /*
165 * Depends on the return element being zeroed.
166 */
167 spin_lock_irqsave(&idp->lock, flags);
168 __move_to_free_list(idp, p);
169 spin_unlock_irqrestore(&idp->lock, flags);
170}
171
172static void idr_mark_full(struct idr_layer **pa, int id)
173{
174 struct idr_layer *p = pa[0];
175 int l = 0;
176
177 __set_bit(id & IDR_MASK, p->bitmap);
178 /*
179 * If this layer is full mark the bit in the layer above to
180 * show that this part of the radix tree is full. This may
181 * complete the layer above and require walking up the radix
182 * tree.
183 */
184 while (bitmap_full(p->bitmap, IDR_SIZE)) {
185 if (!(p = pa[++l]))
186 break;
187 id = id >> IDR_BITS;
188 __set_bit((id & IDR_MASK), p->bitmap);
189 }
190}
191
192static int __idr_pre_get(struct idr *idp, gfp_t gfp_mask)
193{
194 while (idp->id_free_cnt < MAX_IDR_FREE) {
195 struct idr_layer *new;
196 new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
197 if (new == NULL)
198 return (0);
199 move_to_free_list(idp, new);
200 }
201 return 1;
202}
203
204/**
205 * sub_alloc - try to allocate an id without growing the tree depth
206 * @idp: idr handle
207 * @starting_id: id to start search at
208 * @pa: idr_layer[MAX_IDR_LEVEL] used as backtrack buffer
209 * @gfp_mask: allocation mask for idr_layer_alloc()
210 * @layer_idr: optional idr passed to idr_layer_alloc()
211 *
212 * Allocate an id in range [@starting_id, INT_MAX] from @idp without
213 * growing its depth. Returns
214 *
215 * the allocated id >= 0 if successful,
216 * -EAGAIN if the tree needs to grow for allocation to succeed,
217 * -ENOSPC if the id space is exhausted,
218 * -ENOMEM if more idr_layers need to be allocated.
219 */
220static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa,
221 gfp_t gfp_mask, struct idr *layer_idr)
222{
223 int n, m, sh;
224 struct idr_layer *p, *new;
225 int l, id, oid;
226
227 id = *starting_id;
228 restart:
229 p = idp->top;
230 l = idp->layers;
231 pa[l--] = NULL;
232 while (1) {
233 /*
234 * We run around this while until we reach the leaf node...
235 */
236 n = (id >> (IDR_BITS*l)) & IDR_MASK;
237 m = find_next_zero_bit(p->bitmap, IDR_SIZE, n);
238 if (m == IDR_SIZE) {
239 /* no space available go back to previous layer. */
240 l++;
241 oid = id;
242 id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
243
244 /* if already at the top layer, we need to grow */
245 if (id > idr_max(idp->layers)) {
246 *starting_id = id;
247 return -EAGAIN;
248 }
249 p = pa[l];
250 BUG_ON(!p);
251
252 /* If we need to go up one layer, continue the
253 * loop; otherwise, restart from the top.
254 */
255 sh = IDR_BITS * (l + 1);
256 if (oid >> sh == id >> sh)
257 continue;
258 else
259 goto restart;
260 }
261 if (m != n) {
262 sh = IDR_BITS*l;
263 id = ((id >> sh) ^ n ^ m) << sh;
264 }
265 if ((id >= MAX_IDR_BIT) || (id < 0))
266 return -ENOSPC;
267 if (l == 0)
268 break;
269 /*
270 * Create the layer below if it is missing.
271 */
272 if (!p->ary[m]) {
273 new = idr_layer_alloc(gfp_mask, layer_idr);
274 if (!new)
275 return -ENOMEM;
276 new->layer = l-1;
277 new->prefix = id & idr_layer_prefix_mask(new->layer);
278 rcu_assign_pointer(p->ary[m], new);
279 p->count++;
280 }
281 pa[l--] = p;
282 p = p->ary[m];
283 }
284
285 pa[l] = p;
286 return id;
287}
288
289static int idr_get_empty_slot(struct idr *idp, int starting_id,
290 struct idr_layer **pa, gfp_t gfp_mask,
291 struct idr *layer_idr)
292{
293 struct idr_layer *p, *new;
294 int layers, v, id;
295 unsigned long flags;
296
297 id = starting_id;
298build_up:
299 p = idp->top;
300 layers = idp->layers;
301 if (unlikely(!p)) {
302 if (!(p = idr_layer_alloc(gfp_mask, layer_idr)))
303 return -ENOMEM;
304 p->layer = 0;
305 layers = 1;
306 }
307 /*
308 * Add a new layer to the top of the tree if the requested
309 * id is larger than the currently allocated space.
310 */
311 while (id > idr_max(layers)) {
312 layers++;
313 if (!p->count) {
314 /* special case: if the tree is currently empty,
315 * then we grow the tree by moving the top node
316 * upwards.
317 */
318 p->layer++;
319 WARN_ON_ONCE(p->prefix);
320 continue;
321 }
322 if (!(new = idr_layer_alloc(gfp_mask, layer_idr))) {
323 /*
324 * The allocation failed. If we built part of
325 * the structure tear it down.
326 */
327 spin_lock_irqsave(&idp->lock, flags);
328 for (new = p; p && p != idp->top; new = p) {
329 p = p->ary[0];
330 new->ary[0] = NULL;
331 new->count = 0;
332 bitmap_clear(new->bitmap, 0, IDR_SIZE);
333 __move_to_free_list(idp, new);
334 }
335 spin_unlock_irqrestore(&idp->lock, flags);
336 return -ENOMEM;
337 }
338 new->ary[0] = p;
339 new->count = 1;
340 new->layer = layers-1;
341 new->prefix = id & idr_layer_prefix_mask(new->layer);
342 if (bitmap_full(p->bitmap, IDR_SIZE))
343 __set_bit(0, new->bitmap);
344 p = new;
345 }
346 rcu_assign_pointer(idp->top, p);
347 idp->layers = layers;
348 v = sub_alloc(idp, &id, pa, gfp_mask, layer_idr);
349 if (v == -EAGAIN)
350 goto build_up;
351 return(v);
352}
353
354/*
355 * @id and @pa are from a successful allocation from idr_get_empty_slot().
356 * Install the user pointer @ptr and mark the slot full.
357 */
358static void idr_fill_slot(struct idr *idr, void *ptr, int id,
359 struct idr_layer **pa)
360{
361 /* update hint used for lookup, cleared from free_layer() */
362 rcu_assign_pointer(idr->hint, pa[0]);
363
364 rcu_assign_pointer(pa[0]->ary[id & IDR_MASK], (struct idr_layer *)ptr);
365 pa[0]->count++;
366 idr_mark_full(pa, id);
367}
368
369
370/**
371 * idr_preload - preload for idr_alloc()
372 * @gfp_mask: allocation mask to use for preloading
373 *
374 * Preload per-cpu layer buffer for idr_alloc(). Can only be used from
375 * process context and each idr_preload() invocation should be matched with
376 * idr_preload_end(). Note that preemption is disabled while preloaded.
377 *
378 * The first idr_alloc() in the preloaded section can be treated as if it
379 * were invoked with @gfp_mask used for preloading. This allows using more
380 * permissive allocation masks for idrs protected by spinlocks.
381 *
382 * For example, if idr_alloc() below fails, the failure can be treated as
383 * if idr_alloc() were called with GFP_KERNEL rather than GFP_NOWAIT.
384 *
385 * idr_preload(GFP_KERNEL);
386 * spin_lock(lock);
387 *
388 * id = idr_alloc(idr, ptr, start, end, GFP_NOWAIT);
389 *
390 * spin_unlock(lock);
391 * idr_preload_end();
392 * if (id < 0)
393 * error;
394 */
395void idr_preload(gfp_t gfp_mask)
396{
397 /*
398 * Consuming preload buffer from non-process context breaks preload
399 * allocation guarantee. Disallow usage from those contexts.
400 */
401 WARN_ON_ONCE(in_interrupt());
402 might_sleep_if(gfpflags_allow_blocking(gfp_mask));
403
404 preempt_disable();
405
406 /*
407 * idr_alloc() is likely to succeed w/o full idr_layer buffer and
408 * return value from idr_alloc() needs to be checked for failure
409 * anyway. Silently give up if allocation fails. The caller can
410 * treat failures from idr_alloc() as if idr_alloc() were called
411 * with @gfp_mask which should be enough.
412 */
413 while (__this_cpu_read(idr_preload_cnt) < MAX_IDR_FREE) {
414 struct idr_layer *new;
415
416 preempt_enable();
417 new = kmem_cache_zalloc(idr_layer_cache, gfp_mask);
418 preempt_disable();
419 if (!new)
420 break;
421
422 /* link the new one to per-cpu preload list */
423 new->ary[0] = __this_cpu_read(idr_preload_head);
424 __this_cpu_write(idr_preload_head, new);
425 __this_cpu_inc(idr_preload_cnt);
426 }
427}
428EXPORT_SYMBOL(idr_preload);
429
430/**
431 * idr_alloc - allocate new idr entry
432 * @idr: the (initialized) idr
433 * @ptr: pointer to be associated with the new id 13 * @ptr: pointer to be associated with the new id
434 * @start: the minimum id (inclusive) 14 * @start: the minimum id (inclusive)
435 * @end: the maximum id (exclusive, <= 0 for max) 15 * @end: the maximum id (exclusive)
436 * @gfp_mask: memory allocation flags 16 * @gfp: memory allocation flags
437 * 17 *
438 * Allocate an id in [start, end) and associate it with @ptr. If no ID is 18 * Allocates an unused ID in the range [start, end). Returns -ENOSPC
439 * available in the specified range, returns -ENOSPC. On memory allocation 19 * if there are no unused IDs in that range.
440 * failure, returns -ENOMEM.
441 * 20 *
442 * Note that @end is treated as max when <= 0. This is to always allow 21 * Note that @end is treated as max when <= 0. This is to always allow
443 * using @start + N as @end as long as N is inside integer range. 22 * using @start + N as @end as long as N is inside integer range.
444 * 23 *
445 * The user is responsible for exclusively synchronizing all operations 24 * Simultaneous modifications to the @idr are not allowed and should be
446 * which may modify @idr. However, read-only accesses such as idr_find() 25 * prevented by the user, usually with a lock. idr_alloc() may be called
447 * or iteration can be performed under RCU read lock provided the user 26 * concurrently with read-only accesses to the @idr, such as idr_find() and
448 * destroys @ptr in RCU-safe way after removal from idr. 27 * idr_for_each_entry().
449 */ 28 */
450int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask) 29int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp)
451{ 30{
452 int max = end > 0 ? end - 1 : INT_MAX; /* inclusive upper limit */ 31 void __rcu **slot;
453 struct idr_layer *pa[MAX_IDR_LEVEL + 1]; 32 struct radix_tree_iter iter;
454 int id;
455 33
456 might_sleep_if(gfpflags_allow_blocking(gfp_mask));
457
458 /* sanity checks */
459 if (WARN_ON_ONCE(start < 0)) 34 if (WARN_ON_ONCE(start < 0))
460 return -EINVAL; 35 return -EINVAL;
461 if (unlikely(max < start)) 36 if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr)))
462 return -ENOSPC; 37 return -EINVAL;
463 38
464 /* allocate id */ 39 radix_tree_iter_init(&iter, start);
465 id = idr_get_empty_slot(idr, start, pa, gfp_mask, NULL); 40 slot = idr_get_free(&idr->idr_rt, &iter, gfp, end);
466 if (unlikely(id < 0)) 41 if (IS_ERR(slot))
467 return id; 42 return PTR_ERR(slot);
468 if (unlikely(id > max))
469 return -ENOSPC;
470 43
471 idr_fill_slot(idr, ptr, id, pa); 44 radix_tree_iter_replace(&idr->idr_rt, &iter, slot, ptr);
472 return id; 45 radix_tree_iter_tag_clear(&idr->idr_rt, &iter, IDR_FREE);
46 return iter.index;
473} 47}
474EXPORT_SYMBOL_GPL(idr_alloc); 48EXPORT_SYMBOL_GPL(idr_alloc);
475 49
476/** 50/**
477 * idr_alloc_cyclic - allocate new idr entry in a cyclical fashion 51 * idr_alloc_cyclic - allocate new idr entry in a cyclical fashion
478 * @idr: the (initialized) idr 52 * @idr: idr handle
479 * @ptr: pointer to be associated with the new id 53 * @ptr: pointer to be associated with the new id
480 * @start: the minimum id (inclusive) 54 * @start: the minimum id (inclusive)
481 * @end: the maximum id (exclusive, <= 0 for max) 55 * @end: the maximum id (exclusive)
482 * @gfp_mask: memory allocation flags 56 * @gfp: memory allocation flags
483 *
484 * Essentially the same as idr_alloc, but prefers to allocate progressively
485 * higher ids if it can. If the "cur" counter wraps, then it will start again
486 * at the "start" end of the range and allocate one that has already been used.
487 */
488int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end,
489 gfp_t gfp_mask)
490{
491 int id;
492
493 id = idr_alloc(idr, ptr, max(start, idr->cur), end, gfp_mask);
494 if (id == -ENOSPC)
495 id = idr_alloc(idr, ptr, start, end, gfp_mask);
496
497 if (likely(id >= 0))
498 idr->cur = id + 1;
499 return id;
500}
501EXPORT_SYMBOL(idr_alloc_cyclic);
502
503static void idr_remove_warning(int id)
504{
505 WARN(1, "idr_remove called for id=%d which is not allocated.\n", id);
506}
507
508static void sub_remove(struct idr *idp, int shift, int id)
509{
510 struct idr_layer *p = idp->top;
511 struct idr_layer **pa[MAX_IDR_LEVEL + 1];
512 struct idr_layer ***paa = &pa[0];
513 struct idr_layer *to_free;
514 int n;
515
516 *paa = NULL;
517 *++paa = &idp->top;
518
519 while ((shift > 0) && p) {
520 n = (id >> shift) & IDR_MASK;
521 __clear_bit(n, p->bitmap);
522 *++paa = &p->ary[n];
523 p = p->ary[n];
524 shift -= IDR_BITS;
525 }
526 n = id & IDR_MASK;
527 if (likely(p != NULL && test_bit(n, p->bitmap))) {
528 __clear_bit(n, p->bitmap);
529 RCU_INIT_POINTER(p->ary[n], NULL);
530 to_free = NULL;
531 while(*paa && ! --((**paa)->count)){
532 if (to_free)
533 free_layer(idp, to_free);
534 to_free = **paa;
535 **paa-- = NULL;
536 }
537 if (!*paa)
538 idp->layers = 0;
539 if (to_free)
540 free_layer(idp, to_free);
541 } else
542 idr_remove_warning(id);
543}
544
545/**
546 * idr_remove - remove the given id and free its slot
547 * @idp: idr handle
548 * @id: unique key
549 */
550void idr_remove(struct idr *idp, int id)
551{
552 struct idr_layer *p;
553 struct idr_layer *to_free;
554
555 if (id < 0)
556 return;
557
558 if (id > idr_max(idp->layers)) {
559 idr_remove_warning(id);
560 return;
561 }
562
563 sub_remove(idp, (idp->layers - 1) * IDR_BITS, id);
564 if (idp->top && idp->top->count == 1 && (idp->layers > 1) &&
565 idp->top->ary[0]) {
566 /*
567 * Single child at leftmost slot: we can shrink the tree.
568 * This level is not needed anymore since when layers are
569 * inserted, they are inserted at the top of the existing
570 * tree.
571 */
572 to_free = idp->top;
573 p = idp->top->ary[0];
574 rcu_assign_pointer(idp->top, p);
575 --idp->layers;
576 to_free->count = 0;
577 bitmap_clear(to_free->bitmap, 0, IDR_SIZE);
578 free_layer(idp, to_free);
579 }
580}
581EXPORT_SYMBOL(idr_remove);
582
583static void __idr_remove_all(struct idr *idp)
584{
585 int n, id, max;
586 int bt_mask;
587 struct idr_layer *p;
588 struct idr_layer *pa[MAX_IDR_LEVEL + 1];
589 struct idr_layer **paa = &pa[0];
590
591 n = idp->layers * IDR_BITS;
592 *paa = idp->top;
593 RCU_INIT_POINTER(idp->top, NULL);
594 max = idr_max(idp->layers);
595
596 id = 0;
597 while (id >= 0 && id <= max) {
598 p = *paa;
599 while (n > IDR_BITS && p) {
600 n -= IDR_BITS;
601 p = p->ary[(id >> n) & IDR_MASK];
602 *++paa = p;
603 }
604
605 bt_mask = id;
606 id += 1 << n;
607 /* Get the highest bit that the above add changed from 0->1. */
608 while (n < fls(id ^ bt_mask)) {
609 if (*paa)
610 free_layer(idp, *paa);
611 n += IDR_BITS;
612 --paa;
613 }
614 }
615 idp->layers = 0;
616}
617
618/**
619 * idr_destroy - release all cached layers within an idr tree
620 * @idp: idr handle
621 *
622 * Free all id mappings and all idp_layers. After this function, @idp is
623 * completely unused and can be freed / recycled. The caller is
624 * responsible for ensuring that no one else accesses @idp during or after
625 * idr_destroy().
626 * 57 *
627 * A typical clean-up sequence for objects stored in an idr tree will use 58 * Allocates an ID larger than the last ID allocated if one is available.
628 * idr_for_each() to free all objects, if necessary, then idr_destroy() to 59 * If not, it will attempt to allocate the smallest ID that is larger or
629 * free up the id mappings and cached idr_layers. 60 * equal to @start.
630 */ 61 */
631void idr_destroy(struct idr *idp) 62int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end, gfp_t gfp)
632{ 63{
633 __idr_remove_all(idp); 64 int id, curr = idr->idr_next;
634 65
635 while (idp->id_free_cnt) { 66 if (curr < start)
636 struct idr_layer *p = get_from_free_list(idp); 67 curr = start;
637 kmem_cache_free(idr_layer_cache, p);
638 }
639}
640EXPORT_SYMBOL(idr_destroy);
641 68
642void *idr_find_slowpath(struct idr *idp, int id) 69 id = idr_alloc(idr, ptr, curr, end, gfp);
643{ 70 if ((id == -ENOSPC) && (curr > start))
644 int n; 71 id = idr_alloc(idr, ptr, start, curr, gfp);
645 struct idr_layer *p;
646
647 if (id < 0)
648 return NULL;
649
650 p = rcu_dereference_raw(idp->top);
651 if (!p)
652 return NULL;
653 n = (p->layer+1) * IDR_BITS;
654 72
655 if (id > idr_max(p->layer + 1)) 73 if (id >= 0)
656 return NULL; 74 idr->idr_next = id + 1U;
657 BUG_ON(n == 0);
658 75
659 while (n > 0 && p) { 76 return id;
660 n -= IDR_BITS;
661 BUG_ON(n != p->layer*IDR_BITS);
662 p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
663 }
664 return((void *)p);
665} 77}
666EXPORT_SYMBOL(idr_find_slowpath); 78EXPORT_SYMBOL(idr_alloc_cyclic);
667 79
668/** 80/**
669 * idr_for_each - iterate through all stored pointers 81 * idr_for_each - iterate through all stored pointers
670 * @idp: idr handle 82 * @idr: idr handle
671 * @fn: function to be called for each pointer 83 * @fn: function to be called for each pointer
672 * @data: data passed back to callback function 84 * @data: data passed to callback function
673 * 85 *
674 * Iterate over the pointers registered with the given idr. The 86 * The callback function will be called for each entry in @idr, passing
675 * callback function will be called for each pointer currently 87 * the id, the pointer and the data pointer passed to this function.
676 * registered, passing the id, the pointer and the data pointer passed
677 * to this function. It is not safe to modify the idr tree while in
678 * the callback, so functions such as idr_get_new and idr_remove are
679 * not allowed.
680 * 88 *
681 * We check the return of @fn each time. If it returns anything other 89 * If @fn returns anything other than %0, the iteration stops and that
682 * than %0, we break out and return that value. 90 * value is returned from this function.
683 * 91 *
684 * The caller must serialize idr_for_each() vs idr_get_new() and idr_remove(). 92 * idr_for_each() can be called concurrently with idr_alloc() and
93 * idr_remove() if protected by RCU. Newly added entries may not be
94 * seen and deleted entries may be seen, but adding and removing entries
95 * will not cause other entries to be skipped, nor spurious ones to be seen.
685 */ 96 */
686int idr_for_each(struct idr *idp, 97int idr_for_each(const struct idr *idr,
687 int (*fn)(int id, void *p, void *data), void *data) 98 int (*fn)(int id, void *p, void *data), void *data)
688{ 99{
689 int n, id, max, error = 0; 100 struct radix_tree_iter iter;
690 struct idr_layer *p; 101 void __rcu **slot;
691 struct idr_layer *pa[MAX_IDR_LEVEL + 1];
692 struct idr_layer **paa = &pa[0];
693
694 n = idp->layers * IDR_BITS;
695 *paa = rcu_dereference_raw(idp->top);
696 max = idr_max(idp->layers);
697 102
698 id = 0; 103 radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, 0) {
699 while (id >= 0 && id <= max) { 104 int ret = fn(iter.index, rcu_dereference_raw(*slot), data);
700 p = *paa; 105 if (ret)
701 while (n > 0 && p) { 106 return ret;
702 n -= IDR_BITS;
703 p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
704 *++paa = p;
705 }
706
707 if (p) {
708 error = fn(id, (void *)p, data);
709 if (error)
710 break;
711 }
712
713 id += 1 << n;
714 while (n < fls(id)) {
715 n += IDR_BITS;
716 --paa;
717 }
718 } 107 }
719 108
720 return error; 109 return 0;
721} 110}
722EXPORT_SYMBOL(idr_for_each); 111EXPORT_SYMBOL(idr_for_each);
723 112
724/** 113/**
725 * idr_get_next - lookup next object of id to given id. 114 * idr_get_next - Find next populated entry
726 * @idp: idr handle 115 * @idr: idr handle
727 * @nextidp: pointer to lookup key 116 * @nextid: Pointer to lowest possible ID to return
728 * 117 *
729 * Returns pointer to registered object with id, which is next number to 118 * Returns the next populated entry in the tree with an ID greater than
730 * given id. After being looked up, *@nextidp will be updated for the next 119 * or equal to the value pointed to by @nextid. On exit, @nextid is updated
731 * iteration. 120 * to the ID of the found value. To use in a loop, the value pointed to by
732 * 121 * nextid must be incremented by the user.
733 * This function can be called under rcu_read_lock(), given that the leaf
734 * pointers lifetimes are correctly managed.
735 */ 122 */
736void *idr_get_next(struct idr *idp, int *nextidp) 123void *idr_get_next(struct idr *idr, int *nextid)
737{ 124{
738 struct idr_layer *p, *pa[MAX_IDR_LEVEL + 1]; 125 struct radix_tree_iter iter;
739 struct idr_layer **paa = &pa[0]; 126 void __rcu **slot;
740 int id = *nextidp;
741 int n, max;
742 127
743 /* find first ent */ 128 slot = radix_tree_iter_find(&idr->idr_rt, &iter, *nextid);
744 p = *paa = rcu_dereference_raw(idp->top); 129 if (!slot)
745 if (!p)
746 return NULL; 130 return NULL;
747 n = (p->layer + 1) * IDR_BITS;
748 max = idr_max(p->layer + 1);
749
750 while (id >= 0 && id <= max) {
751 p = *paa;
752 while (n > 0 && p) {
753 n -= IDR_BITS;
754 p = rcu_dereference_raw(p->ary[(id >> n) & IDR_MASK]);
755 *++paa = p;
756 }
757
758 if (p) {
759 *nextidp = id;
760 return p;
761 }
762 131
763 /* 132 *nextid = iter.index;
764 * Proceed to the next layer at the current level. Unlike 133 return rcu_dereference_raw(*slot);
765 * idr_for_each(), @id isn't guaranteed to be aligned to
766 * layer boundary at this point and adding 1 << n may
767 * incorrectly skip IDs. Make sure we jump to the
768 * beginning of the next layer using round_up().
769 */
770 id = round_up(id + 1, 1 << n);
771 while (n < fls(id)) {
772 n += IDR_BITS;
773 --paa;
774 }
775 }
776 return NULL;
777} 134}
778EXPORT_SYMBOL(idr_get_next); 135EXPORT_SYMBOL(idr_get_next);
779 136
780
781/** 137/**
782 * idr_replace - replace pointer for given id 138 * idr_replace - replace pointer for given id
783 * @idp: idr handle 139 * @idr: idr handle
784 * @ptr: pointer you want associated with the id 140 * @ptr: New pointer to associate with the ID
785 * @id: lookup key 141 * @id: Lookup key
786 * 142 *
787 * Replace the pointer registered with an id and return the old value. 143 * Replace the pointer registered with an ID and return the old value.
788 * A %-ENOENT return indicates that @id was not found. 144 * This function can be called under the RCU read lock concurrently with
789 * A %-EINVAL return indicates that @id was not within valid constraints. 145 * idr_alloc() and idr_remove() (as long as the ID being removed is not
146 * the one being replaced!).
790 * 147 *
791 * The caller must serialize with writers. 148 * Returns: 0 on success. %-ENOENT indicates that @id was not found.
149 * %-EINVAL indicates that @id or @ptr were not valid.
792 */ 150 */
793void *idr_replace(struct idr *idp, void *ptr, int id) 151void *idr_replace(struct idr *idr, void *ptr, int id)
794{ 152{
795 int n; 153 struct radix_tree_node *node;
796 struct idr_layer *p, *old_p; 154 void __rcu **slot = NULL;
155 void *entry;
797 156
798 if (id < 0) 157 if (WARN_ON_ONCE(id < 0))
158 return ERR_PTR(-EINVAL);
159 if (WARN_ON_ONCE(radix_tree_is_internal_node(ptr)))
799 return ERR_PTR(-EINVAL); 160 return ERR_PTR(-EINVAL);
800 161
801 p = idp->top; 162 entry = __radix_tree_lookup(&idr->idr_rt, id, &node, &slot);
802 if (!p) 163 if (!slot || radix_tree_tag_get(&idr->idr_rt, id, IDR_FREE))
803 return ERR_PTR(-ENOENT);
804
805 if (id > idr_max(p->layer + 1))
806 return ERR_PTR(-ENOENT);
807
808 n = p->layer * IDR_BITS;
809 while ((n > 0) && p) {
810 p = p->ary[(id >> n) & IDR_MASK];
811 n -= IDR_BITS;
812 }
813
814 n = id & IDR_MASK;
815 if (unlikely(p == NULL || !test_bit(n, p->bitmap)))
816 return ERR_PTR(-ENOENT); 164 return ERR_PTR(-ENOENT);
817 165
818 old_p = p->ary[n]; 166 __radix_tree_replace(&idr->idr_rt, node, slot, ptr, NULL, NULL);
819 rcu_assign_pointer(p->ary[n], ptr);
820 167
821 return old_p; 168 return entry;
822} 169}
823EXPORT_SYMBOL(idr_replace); 170EXPORT_SYMBOL(idr_replace);
824 171
825void __init idr_init_cache(void)
826{
827 idr_layer_cache = kmem_cache_create("idr_layer_cache",
828 sizeof(struct idr_layer), 0, SLAB_PANIC, NULL);
829}
830
831/**
832 * idr_init - initialize idr handle
833 * @idp: idr handle
834 *
835 * This function is use to set up the handle (@idp) that you will pass
836 * to the rest of the functions.
837 */
838void idr_init(struct idr *idp)
839{
840 memset(idp, 0, sizeof(struct idr));
841 spin_lock_init(&idp->lock);
842}
843EXPORT_SYMBOL(idr_init);
844
845static int idr_has_entry(int id, void *p, void *data)
846{
847 return 1;
848}
849
850bool idr_is_empty(struct idr *idp)
851{
852 return !idr_for_each(idp, idr_has_entry, NULL);
853}
854EXPORT_SYMBOL(idr_is_empty);
855
856/** 172/**
857 * DOC: IDA description 173 * DOC: IDA description
858 * IDA - IDR based ID allocator
859 * 174 *
860 * This is id allocator without id -> pointer translation. Memory 175 * The IDA is an ID allocator which does not provide the ability to
861 * usage is much lower than full blown idr because each id only 176 * associate an ID with a pointer. As such, it only needs to store one
862 * occupies a bit. ida uses a custom leaf node which contains 177 * bit per ID, and so is more space efficient than an IDR. To use an IDA,
863 * IDA_BITMAP_BITS slots. 178 * define it using DEFINE_IDA() (or embed a &struct ida in a data structure,
864 * 179 * then initialise it using ida_init()). To allocate a new ID, call
865 * 2007-04-25 written by Tejun Heo <htejun@gmail.com> 180 * ida_simple_get(). To free an ID, call ida_simple_remove().
181 *
182 * If you have more complex locking requirements, use a loop around
183 * ida_pre_get() and ida_get_new() to allocate a new ID. Then use
184 * ida_remove() to free an ID. You must make sure that ida_get_new() and
185 * ida_remove() cannot be called at the same time as each other for the
186 * same IDA.
187 *
188 * You can also use ida_get_new_above() if you need an ID to be allocated
189 * above a particular number. ida_destroy() can be used to dispose of an
190 * IDA without needing to free the individual IDs in it. You can use
191 * ida_is_empty() to find out whether the IDA has any IDs currently allocated.
192 *
193 * IDs are currently limited to the range [0-INT_MAX]. If this is an awkward
194 * limitation, it should be quite straightforward to raise the maximum.
866 */ 195 */
867 196
868static void free_bitmap(struct ida *ida, struct ida_bitmap *bitmap) 197/*
869{ 198 * Developer's notes:
870 unsigned long flags; 199 *
871 200 * The IDA uses the functionality provided by the IDR & radix tree to store
872 if (!ida->free_bitmap) { 201 * bitmaps in each entry. The IDR_FREE tag means there is at least one bit
873 spin_lock_irqsave(&ida->idr.lock, flags); 202 * free, unlike the IDR where it means at least one entry is free.
874 if (!ida->free_bitmap) { 203 *
875 ida->free_bitmap = bitmap; 204 * I considered telling the radix tree that each slot is an order-10 node
876 bitmap = NULL; 205 * and storing the bit numbers in the radix tree, but the radix tree can't
877 } 206 * allow a single multiorder entry at index 0, which would significantly
878 spin_unlock_irqrestore(&ida->idr.lock, flags); 207 * increase memory consumption for the IDA. So instead we divide the index
879 } 208 * by the number of bits in the leaf bitmap before doing a radix tree lookup.
880 209 *
881 kfree(bitmap); 210 * As an optimisation, if there are only a few low bits set in any given
882} 211 * leaf, instead of allocating a 128-byte bitmap, we use the 'exceptional
883 212 * entry' functionality of the radix tree to store BITS_PER_LONG - 2 bits
884/** 213 * directly in the entry. By being really tricksy, we could store
885 * ida_pre_get - reserve resources for ida allocation 214 * BITS_PER_LONG - 1 bits, but there're diminishing returns after optimising
886 * @ida: ida handle 215 * for 0-3 allocated IDs.
887 * @gfp_mask: memory allocation flag 216 *
888 * 217 * We allow the radix tree 'exceptional' count to get out of date. Nothing
889 * This function should be called prior to locking and calling the 218 * in the IDA nor the radix tree code checks it. If it becomes important
890 * following function. It preallocates enough memory to satisfy the 219 * to maintain an accurate exceptional count, switch the rcu_assign_pointer()
891 * worst possible allocation. 220 * calls to radix_tree_iter_replace() which will correct the exceptional
892 * 221 * count.
893 * If the system is REALLY out of memory this function returns %0, 222 *
894 * otherwise %1. 223 * The IDA always requires a lock to alloc/free. If we add a 'test_bit'
224 * equivalent, it will still need locking. Going to RCU lookup would require
225 * using RCU to free bitmaps, and that's not trivial without embedding an
226 * RCU head in the bitmap, which adds a 2-pointer overhead to each 128-byte
227 * bitmap, which is excessive.
895 */ 228 */
896int ida_pre_get(struct ida *ida, gfp_t gfp_mask)
897{
898 /* allocate idr_layers */
899 if (!__idr_pre_get(&ida->idr, gfp_mask))
900 return 0;
901 229
902 /* allocate free_bitmap */ 230#define IDA_MAX (0x80000000U / IDA_BITMAP_BITS)
903 if (!ida->free_bitmap) {
904 struct ida_bitmap *bitmap;
905
906 bitmap = kmalloc(sizeof(struct ida_bitmap), gfp_mask);
907 if (!bitmap)
908 return 0;
909
910 free_bitmap(ida, bitmap);
911 }
912
913 return 1;
914}
915EXPORT_SYMBOL(ida_pre_get);
916 231
917/** 232/**
918 * ida_get_new_above - allocate new ID above or equal to a start id 233 * ida_get_new_above - allocate new ID above or equal to a start id
919 * @ida: ida handle 234 * @ida: ida handle
920 * @starting_id: id to start search at 235 * @start: id to start search at
921 * @p_id: pointer to the allocated handle 236 * @id: pointer to the allocated handle
922 * 237 *
923 * Allocate new ID above or equal to @starting_id. It should be called 238 * Allocate new ID above or equal to @start. It should be called
924 * with any required locks. 239 * with any required locks to ensure that concurrent calls to
240 * ida_get_new_above() / ida_get_new() / ida_remove() are not allowed.
241 * Consider using ida_simple_get() if you do not have complex locking
242 * requirements.
925 * 243 *
926 * If memory is required, it will return %-EAGAIN, you should unlock 244 * If memory is required, it will return %-EAGAIN, you should unlock
927 * and go back to the ida_pre_get() call. If the ida is full, it will 245 * and go back to the ida_pre_get() call. If the ida is full, it will
928 * return %-ENOSPC. 246 * return %-ENOSPC. On success, it will return 0.
929 *
930 * Note that callers must ensure that concurrent access to @ida is not possible.
931 * See ida_simple_get() for a varaint which takes care of locking.
932 * 247 *
933 * @p_id returns a value in the range @starting_id ... %0x7fffffff. 248 * @id returns a value in the range @start ... %0x7fffffff.
934 */ 249 */
935int ida_get_new_above(struct ida *ida, int starting_id, int *p_id) 250int ida_get_new_above(struct ida *ida, int start, int *id)
936{ 251{
937 struct idr_layer *pa[MAX_IDR_LEVEL + 1]; 252 struct radix_tree_root *root = &ida->ida_rt;
253 void __rcu **slot;
254 struct radix_tree_iter iter;
938 struct ida_bitmap *bitmap; 255 struct ida_bitmap *bitmap;
939 unsigned long flags; 256 unsigned long index;
940 int idr_id = starting_id / IDA_BITMAP_BITS; 257 unsigned bit, ebit;
941 int offset = starting_id % IDA_BITMAP_BITS; 258 int new;
942 int t, id; 259
943 260 index = start / IDA_BITMAP_BITS;
944 restart: 261 bit = start % IDA_BITMAP_BITS;
945 /* get vacant slot */ 262 ebit = bit + RADIX_TREE_EXCEPTIONAL_SHIFT;
946 t = idr_get_empty_slot(&ida->idr, idr_id, pa, 0, &ida->idr); 263
947 if (t < 0) 264 slot = radix_tree_iter_init(&iter, index);
948 return t == -ENOMEM ? -EAGAIN : t; 265 for (;;) {
949 266 if (slot)
950 if (t * IDA_BITMAP_BITS >= MAX_IDR_BIT) 267 slot = radix_tree_next_slot(slot, &iter,
951 return -ENOSPC; 268 RADIX_TREE_ITER_TAGGED);
952 269 if (!slot) {
953 if (t != idr_id) 270 slot = idr_get_free(root, &iter, GFP_NOWAIT, IDA_MAX);
954 offset = 0; 271 if (IS_ERR(slot)) {
955 idr_id = t; 272 if (slot == ERR_PTR(-ENOMEM))
956 273 return -EAGAIN;
957 /* if bitmap isn't there, create a new one */ 274 return PTR_ERR(slot);
958 bitmap = (void *)pa[0]->ary[idr_id & IDR_MASK]; 275 }
959 if (!bitmap) { 276 }
960 spin_lock_irqsave(&ida->idr.lock, flags); 277 if (iter.index > index) {
961 bitmap = ida->free_bitmap; 278 bit = 0;
962 ida->free_bitmap = NULL; 279 ebit = RADIX_TREE_EXCEPTIONAL_SHIFT;
963 spin_unlock_irqrestore(&ida->idr.lock, flags); 280 }
964 281 new = iter.index * IDA_BITMAP_BITS;
965 if (!bitmap) 282 bitmap = rcu_dereference_raw(*slot);
966 return -EAGAIN; 283 if (radix_tree_exception(bitmap)) {
967 284 unsigned long tmp = (unsigned long)bitmap;
968 memset(bitmap, 0, sizeof(struct ida_bitmap)); 285 ebit = find_next_zero_bit(&tmp, BITS_PER_LONG, ebit);
969 rcu_assign_pointer(pa[0]->ary[idr_id & IDR_MASK], 286 if (ebit < BITS_PER_LONG) {
970 (void *)bitmap); 287 tmp |= 1UL << ebit;
971 pa[0]->count++; 288 rcu_assign_pointer(*slot, (void *)tmp);
972 } 289 *id = new + ebit - RADIX_TREE_EXCEPTIONAL_SHIFT;
973 290 return 0;
974 /* lookup for empty slot */ 291 }
975 t = find_next_zero_bit(bitmap->bitmap, IDA_BITMAP_BITS, offset); 292 bitmap = this_cpu_xchg(ida_bitmap, NULL);
976 if (t == IDA_BITMAP_BITS) { 293 if (!bitmap)
977 /* no empty slot after offset, continue to the next chunk */ 294 return -EAGAIN;
978 idr_id++; 295 memset(bitmap, 0, sizeof(*bitmap));
979 offset = 0; 296 bitmap->bitmap[0] = tmp >> RADIX_TREE_EXCEPTIONAL_SHIFT;
980 goto restart; 297 rcu_assign_pointer(*slot, bitmap);
981 } 298 }
982
983 id = idr_id * IDA_BITMAP_BITS + t;
984 if (id >= MAX_IDR_BIT)
985 return -ENOSPC;
986 299
987 __set_bit(t, bitmap->bitmap); 300 if (bitmap) {
988 if (++bitmap->nr_busy == IDA_BITMAP_BITS) 301 bit = find_next_zero_bit(bitmap->bitmap,
989 idr_mark_full(pa, idr_id); 302 IDA_BITMAP_BITS, bit);
303 new += bit;
304 if (new < 0)
305 return -ENOSPC;
306 if (bit == IDA_BITMAP_BITS)
307 continue;
990 308
991 *p_id = id; 309 __set_bit(bit, bitmap->bitmap);
310 if (bitmap_full(bitmap->bitmap, IDA_BITMAP_BITS))
311 radix_tree_iter_tag_clear(root, &iter,
312 IDR_FREE);
313 } else {
314 new += bit;
315 if (new < 0)
316 return -ENOSPC;
317 if (ebit < BITS_PER_LONG) {
318 bitmap = (void *)((1UL << ebit) |
319 RADIX_TREE_EXCEPTIONAL_ENTRY);
320 radix_tree_iter_replace(root, &iter, slot,
321 bitmap);
322 *id = new;
323 return 0;
324 }
325 bitmap = this_cpu_xchg(ida_bitmap, NULL);
326 if (!bitmap)
327 return -EAGAIN;
328 memset(bitmap, 0, sizeof(*bitmap));
329 __set_bit(bit, bitmap->bitmap);
330 radix_tree_iter_replace(root, &iter, slot, bitmap);
331 }
992 332
993 /* Each leaf node can handle nearly a thousand slots and the 333 *id = new;
994 * whole idea of ida is to have small memory foot print. 334 return 0;
995 * Throw away extra resources one by one after each successful
996 * allocation.
997 */
998 if (ida->idr.id_free_cnt || ida->free_bitmap) {
999 struct idr_layer *p = get_from_free_list(&ida->idr);
1000 if (p)
1001 kmem_cache_free(idr_layer_cache, p);
1002 } 335 }
1003
1004 return 0;
1005} 336}
1006EXPORT_SYMBOL(ida_get_new_above); 337EXPORT_SYMBOL(ida_get_new_above);
1007 338
1008/** 339/**
1009 * ida_remove - remove the given ID 340 * ida_remove - Free the given ID
1010 * @ida: ida handle 341 * @ida: ida handle
1011 * @id: ID to free 342 * @id: ID to free
343 *
344 * This function should not be called at the same time as ida_get_new_above().
1012 */ 345 */
1013void ida_remove(struct ida *ida, int id) 346void ida_remove(struct ida *ida, int id)
1014{ 347{
1015 struct idr_layer *p = ida->idr.top; 348 unsigned long index = id / IDA_BITMAP_BITS;
1016 int shift = (ida->idr.layers - 1) * IDR_BITS; 349 unsigned offset = id % IDA_BITMAP_BITS;
1017 int idr_id = id / IDA_BITMAP_BITS;
1018 int offset = id % IDA_BITMAP_BITS;
1019 int n;
1020 struct ida_bitmap *bitmap; 350 struct ida_bitmap *bitmap;
351 unsigned long *btmp;
352 struct radix_tree_iter iter;
353 void __rcu **slot;
1021 354
1022 if (idr_id > idr_max(ida->idr.layers)) 355 slot = radix_tree_iter_lookup(&ida->ida_rt, &iter, index);
356 if (!slot)
1023 goto err; 357 goto err;
1024 358
1025 /* clear full bits while looking up the leaf idr_layer */ 359 bitmap = rcu_dereference_raw(*slot);
1026 while ((shift > 0) && p) { 360 if (radix_tree_exception(bitmap)) {
1027 n = (idr_id >> shift) & IDR_MASK; 361 btmp = (unsigned long *)slot;
1028 __clear_bit(n, p->bitmap); 362 offset += RADIX_TREE_EXCEPTIONAL_SHIFT;
1029 p = p->ary[n]; 363 if (offset >= BITS_PER_LONG)
1030 shift -= IDR_BITS; 364 goto err;
365 } else {
366 btmp = bitmap->bitmap;
1031 } 367 }
1032 368 if (!test_bit(offset, btmp))
1033 if (p == NULL)
1034 goto err;
1035
1036 n = idr_id & IDR_MASK;
1037 __clear_bit(n, p->bitmap);
1038
1039 bitmap = (void *)p->ary[n];
1040 if (!bitmap || !test_bit(offset, bitmap->bitmap))
1041 goto err; 369 goto err;
1042 370
1043 /* update bitmap and remove it if empty */ 371 __clear_bit(offset, btmp);
1044 __clear_bit(offset, bitmap->bitmap); 372 radix_tree_iter_tag_set(&ida->ida_rt, &iter, IDR_FREE);
1045 if (--bitmap->nr_busy == 0) { 373 if (radix_tree_exception(bitmap)) {
1046 __set_bit(n, p->bitmap); /* to please idr_remove() */ 374 if (rcu_dereference_raw(*slot) ==
1047 idr_remove(&ida->idr, idr_id); 375 (void *)RADIX_TREE_EXCEPTIONAL_ENTRY)
1048 free_bitmap(ida, bitmap); 376 radix_tree_iter_delete(&ida->ida_rt, &iter, slot);
377 } else if (bitmap_empty(btmp, IDA_BITMAP_BITS)) {
378 kfree(bitmap);
379 radix_tree_iter_delete(&ida->ida_rt, &iter, slot);
1049 } 380 }
1050
1051 return; 381 return;
1052
1053 err: 382 err:
1054 WARN(1, "ida_remove called for id=%d which is not allocated.\n", id); 383 WARN(1, "ida_remove called for id=%d which is not allocated.\n", id);
1055} 384}
1056EXPORT_SYMBOL(ida_remove); 385EXPORT_SYMBOL(ida_remove);
1057 386
1058/** 387/**
1059 * ida_destroy - release all cached layers within an ida tree 388 * ida_destroy - Free the contents of an ida
1060 * @ida: ida handle 389 * @ida: ida handle
390 *
391 * Calling this function releases all resources associated with an IDA. When
392 * this call returns, the IDA is empty and can be reused or freed. The caller
393 * should not allow ida_remove() or ida_get_new_above() to be called at the
394 * same time.
1061 */ 395 */
1062void ida_destroy(struct ida *ida) 396void ida_destroy(struct ida *ida)
1063{ 397{
1064 idr_destroy(&ida->idr); 398 struct radix_tree_iter iter;
1065 kfree(ida->free_bitmap); 399 void __rcu **slot;
400
401 radix_tree_for_each_slot(slot, &ida->ida_rt, &iter, 0) {
402 struct ida_bitmap *bitmap = rcu_dereference_raw(*slot);
403 if (!radix_tree_exception(bitmap))
404 kfree(bitmap);
405 radix_tree_iter_delete(&ida->ida_rt, &iter, slot);
406 }
1066} 407}
1067EXPORT_SYMBOL(ida_destroy); 408EXPORT_SYMBOL(ida_destroy);
1068 409
@@ -1141,18 +482,3 @@ void ida_simple_remove(struct ida *ida, unsigned int id)
1141 spin_unlock_irqrestore(&simple_ida_lock, flags); 482 spin_unlock_irqrestore(&simple_ida_lock, flags);
1142} 483}
1143EXPORT_SYMBOL(ida_simple_remove); 484EXPORT_SYMBOL(ida_simple_remove);
1144
1145/**
1146 * ida_init - initialize ida handle
1147 * @ida: ida handle
1148 *
1149 * This function is use to set up the handle (@ida) that you will pass
1150 * to the rest of the functions.
1151 */
1152void ida_init(struct ida *ida)
1153{
1154 memset(ida, 0, sizeof(struct ida));
1155 idr_init(&ida->idr);
1156
1157}
1158EXPORT_SYMBOL(ida_init);
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 72fab4999c00..5ed506d648c4 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -22,20 +22,21 @@
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 */ 23 */
24 24
25#include <linux/bitmap.h>
26#include <linux/bitops.h>
25#include <linux/cpu.h> 27#include <linux/cpu.h>
26#include <linux/errno.h> 28#include <linux/errno.h>
29#include <linux/export.h>
30#include <linux/idr.h>
27#include <linux/init.h> 31#include <linux/init.h>
28#include <linux/kernel.h> 32#include <linux/kernel.h>
29#include <linux/export.h> 33#include <linux/kmemleak.h>
30#include <linux/radix-tree.h>
31#include <linux/percpu.h> 34#include <linux/percpu.h>
35#include <linux/preempt.h> /* in_interrupt() */
36#include <linux/radix-tree.h>
37#include <linux/rcupdate.h>
32#include <linux/slab.h> 38#include <linux/slab.h>
33#include <linux/kmemleak.h>
34#include <linux/cpu.h>
35#include <linux/string.h> 39#include <linux/string.h>
36#include <linux/bitops.h>
37#include <linux/rcupdate.h>
38#include <linux/preempt.h> /* in_interrupt() */
39 40
40 41
41/* Number of nodes in fully populated tree of given height */ 42/* Number of nodes in fully populated tree of given height */
@@ -60,11 +61,28 @@ static struct kmem_cache *radix_tree_node_cachep;
60#define RADIX_TREE_PRELOAD_SIZE (RADIX_TREE_MAX_PATH * 2 - 1) 61#define RADIX_TREE_PRELOAD_SIZE (RADIX_TREE_MAX_PATH * 2 - 1)
61 62
62/* 63/*
64 * The IDR does not have to be as high as the radix tree since it uses
65 * signed integers, not unsigned longs.
66 */
67#define IDR_INDEX_BITS (8 /* CHAR_BIT */ * sizeof(int) - 1)
68#define IDR_MAX_PATH (DIV_ROUND_UP(IDR_INDEX_BITS, \
69 RADIX_TREE_MAP_SHIFT))
70#define IDR_PRELOAD_SIZE (IDR_MAX_PATH * 2 - 1)
71
72/*
73 * The IDA is even shorter since it uses a bitmap at the last level.
74 */
75#define IDA_INDEX_BITS (8 * sizeof(int) - 1 - ilog2(IDA_BITMAP_BITS))
76#define IDA_MAX_PATH (DIV_ROUND_UP(IDA_INDEX_BITS, \
77 RADIX_TREE_MAP_SHIFT))
78#define IDA_PRELOAD_SIZE (IDA_MAX_PATH * 2 - 1)
79
80/*
63 * Per-cpu pool of preloaded nodes 81 * Per-cpu pool of preloaded nodes
64 */ 82 */
65struct radix_tree_preload { 83struct radix_tree_preload {
66 unsigned nr; 84 unsigned nr;
67 /* nodes->private_data points to next preallocated node */ 85 /* nodes->parent points to next preallocated node */
68 struct radix_tree_node *nodes; 86 struct radix_tree_node *nodes;
69}; 87};
70static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, }; 88static DEFINE_PER_CPU(struct radix_tree_preload, radix_tree_preloads) = { 0, };
@@ -83,35 +101,38 @@ static inline void *node_to_entry(void *ptr)
83 101
84#ifdef CONFIG_RADIX_TREE_MULTIORDER 102#ifdef CONFIG_RADIX_TREE_MULTIORDER
85/* Sibling slots point directly to another slot in the same node */ 103/* Sibling slots point directly to another slot in the same node */
86static inline bool is_sibling_entry(struct radix_tree_node *parent, void *node) 104static inline
105bool is_sibling_entry(const struct radix_tree_node *parent, void *node)
87{ 106{
88 void **ptr = node; 107 void __rcu **ptr = node;
89 return (parent->slots <= ptr) && 108 return (parent->slots <= ptr) &&
90 (ptr < parent->slots + RADIX_TREE_MAP_SIZE); 109 (ptr < parent->slots + RADIX_TREE_MAP_SIZE);
91} 110}
92#else 111#else
93static inline bool is_sibling_entry(struct radix_tree_node *parent, void *node) 112static inline
113bool is_sibling_entry(const struct radix_tree_node *parent, void *node)
94{ 114{
95 return false; 115 return false;
96} 116}
97#endif 117#endif
98 118
99static inline unsigned long get_slot_offset(struct radix_tree_node *parent, 119static inline unsigned long
100 void **slot) 120get_slot_offset(const struct radix_tree_node *parent, void __rcu **slot)
101{ 121{
102 return slot - parent->slots; 122 return slot - parent->slots;
103} 123}
104 124
105static unsigned int radix_tree_descend(struct radix_tree_node *parent, 125static unsigned int radix_tree_descend(const struct radix_tree_node *parent,
106 struct radix_tree_node **nodep, unsigned long index) 126 struct radix_tree_node **nodep, unsigned long index)
107{ 127{
108 unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK; 128 unsigned int offset = (index >> parent->shift) & RADIX_TREE_MAP_MASK;
109 void **entry = rcu_dereference_raw(parent->slots[offset]); 129 void __rcu **entry = rcu_dereference_raw(parent->slots[offset]);
110 130
111#ifdef CONFIG_RADIX_TREE_MULTIORDER 131#ifdef CONFIG_RADIX_TREE_MULTIORDER
112 if (radix_tree_is_internal_node(entry)) { 132 if (radix_tree_is_internal_node(entry)) {
113 if (is_sibling_entry(parent, entry)) { 133 if (is_sibling_entry(parent, entry)) {
114 void **sibentry = (void **) entry_to_node(entry); 134 void __rcu **sibentry;
135 sibentry = (void __rcu **) entry_to_node(entry);
115 offset = get_slot_offset(parent, sibentry); 136 offset = get_slot_offset(parent, sibentry);
116 entry = rcu_dereference_raw(*sibentry); 137 entry = rcu_dereference_raw(*sibentry);
117 } 138 }
@@ -122,7 +143,7 @@ static unsigned int radix_tree_descend(struct radix_tree_node *parent,
122 return offset; 143 return offset;
123} 144}
124 145
125static inline gfp_t root_gfp_mask(struct radix_tree_root *root) 146static inline gfp_t root_gfp_mask(const struct radix_tree_root *root)
126{ 147{
127 return root->gfp_mask & __GFP_BITS_MASK; 148 return root->gfp_mask & __GFP_BITS_MASK;
128} 149}
@@ -139,42 +160,48 @@ static inline void tag_clear(struct radix_tree_node *node, unsigned int tag,
139 __clear_bit(offset, node->tags[tag]); 160 __clear_bit(offset, node->tags[tag]);
140} 161}
141 162
142static inline int tag_get(struct radix_tree_node *node, unsigned int tag, 163static inline int tag_get(const struct radix_tree_node *node, unsigned int tag,
143 int offset) 164 int offset)
144{ 165{
145 return test_bit(offset, node->tags[tag]); 166 return test_bit(offset, node->tags[tag]);
146} 167}
147 168
148static inline void root_tag_set(struct radix_tree_root *root, unsigned int tag) 169static inline void root_tag_set(struct radix_tree_root *root, unsigned tag)
149{ 170{
150 root->gfp_mask |= (__force gfp_t)(1 << (tag + __GFP_BITS_SHIFT)); 171 root->gfp_mask |= (__force gfp_t)(1 << (tag + ROOT_TAG_SHIFT));
151} 172}
152 173
153static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag) 174static inline void root_tag_clear(struct radix_tree_root *root, unsigned tag)
154{ 175{
155 root->gfp_mask &= (__force gfp_t)~(1 << (tag + __GFP_BITS_SHIFT)); 176 root->gfp_mask &= (__force gfp_t)~(1 << (tag + ROOT_TAG_SHIFT));
156} 177}
157 178
158static inline void root_tag_clear_all(struct radix_tree_root *root) 179static inline void root_tag_clear_all(struct radix_tree_root *root)
159{ 180{
160 root->gfp_mask &= __GFP_BITS_MASK; 181 root->gfp_mask &= (1 << ROOT_TAG_SHIFT) - 1;
182}
183
184static inline int root_tag_get(const struct radix_tree_root *root, unsigned tag)
185{
186 return (__force int)root->gfp_mask & (1 << (tag + ROOT_TAG_SHIFT));
161} 187}
162 188
163static inline int root_tag_get(struct radix_tree_root *root, unsigned int tag) 189static inline unsigned root_tags_get(const struct radix_tree_root *root)
164{ 190{
165 return (__force int)root->gfp_mask & (1 << (tag + __GFP_BITS_SHIFT)); 191 return (__force unsigned)root->gfp_mask >> ROOT_TAG_SHIFT;
166} 192}
167 193
168static inline unsigned root_tags_get(struct radix_tree_root *root) 194static inline bool is_idr(const struct radix_tree_root *root)
169{ 195{
170 return (__force unsigned)root->gfp_mask >> __GFP_BITS_SHIFT; 196 return !!(root->gfp_mask & ROOT_IS_IDR);
171} 197}
172 198
173/* 199/*
174 * Returns 1 if any slot in the node has this tag set. 200 * Returns 1 if any slot in the node has this tag set.
175 * Otherwise returns 0. 201 * Otherwise returns 0.
176 */ 202 */
177static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag) 203static inline int any_tag_set(const struct radix_tree_node *node,
204 unsigned int tag)
178{ 205{
179 unsigned idx; 206 unsigned idx;
180 for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) { 207 for (idx = 0; idx < RADIX_TREE_TAG_LONGS; idx++) {
@@ -184,6 +211,11 @@ static inline int any_tag_set(struct radix_tree_node *node, unsigned int tag)
184 return 0; 211 return 0;
185} 212}
186 213
214static inline void all_tag_set(struct radix_tree_node *node, unsigned int tag)
215{
216 bitmap_fill(node->tags[tag], RADIX_TREE_MAP_SIZE);
217}
218
187/** 219/**
188 * radix_tree_find_next_bit - find the next set bit in a memory region 220 * radix_tree_find_next_bit - find the next set bit in a memory region
189 * 221 *
@@ -232,11 +264,18 @@ static inline unsigned long shift_maxindex(unsigned int shift)
232 return (RADIX_TREE_MAP_SIZE << shift) - 1; 264 return (RADIX_TREE_MAP_SIZE << shift) - 1;
233} 265}
234 266
235static inline unsigned long node_maxindex(struct radix_tree_node *node) 267static inline unsigned long node_maxindex(const struct radix_tree_node *node)
236{ 268{
237 return shift_maxindex(node->shift); 269 return shift_maxindex(node->shift);
238} 270}
239 271
272static unsigned long next_index(unsigned long index,
273 const struct radix_tree_node *node,
274 unsigned long offset)
275{
276 return (index & ~node_maxindex(node)) + (offset << node->shift);
277}
278
240#ifndef __KERNEL__ 279#ifndef __KERNEL__
241static void dump_node(struct radix_tree_node *node, unsigned long index) 280static void dump_node(struct radix_tree_node *node, unsigned long index)
242{ 281{
@@ -275,11 +314,59 @@ static void radix_tree_dump(struct radix_tree_root *root)
275{ 314{
276 pr_debug("radix root: %p rnode %p tags %x\n", 315 pr_debug("radix root: %p rnode %p tags %x\n",
277 root, root->rnode, 316 root, root->rnode,
278 root->gfp_mask >> __GFP_BITS_SHIFT); 317 root->gfp_mask >> ROOT_TAG_SHIFT);
279 if (!radix_tree_is_internal_node(root->rnode)) 318 if (!radix_tree_is_internal_node(root->rnode))
280 return; 319 return;
281 dump_node(entry_to_node(root->rnode), 0); 320 dump_node(entry_to_node(root->rnode), 0);
282} 321}
322
323static void dump_ida_node(void *entry, unsigned long index)
324{
325 unsigned long i;
326
327 if (!entry)
328 return;
329
330 if (radix_tree_is_internal_node(entry)) {
331 struct radix_tree_node *node = entry_to_node(entry);
332
333 pr_debug("ida node: %p offset %d indices %lu-%lu parent %p free %lx shift %d count %d\n",
334 node, node->offset, index * IDA_BITMAP_BITS,
335 ((index | node_maxindex(node)) + 1) *
336 IDA_BITMAP_BITS - 1,
337 node->parent, node->tags[0][0], node->shift,
338 node->count);
339 for (i = 0; i < RADIX_TREE_MAP_SIZE; i++)
340 dump_ida_node(node->slots[i],
341 index | (i << node->shift));
342 } else if (radix_tree_exceptional_entry(entry)) {
343 pr_debug("ida excp: %p offset %d indices %lu-%lu data %lx\n",
344 entry, (int)(index & RADIX_TREE_MAP_MASK),
345 index * IDA_BITMAP_BITS,
346 index * IDA_BITMAP_BITS + BITS_PER_LONG -
347 RADIX_TREE_EXCEPTIONAL_SHIFT,
348 (unsigned long)entry >>
349 RADIX_TREE_EXCEPTIONAL_SHIFT);
350 } else {
351 struct ida_bitmap *bitmap = entry;
352
353 pr_debug("ida btmp: %p offset %d indices %lu-%lu data", bitmap,
354 (int)(index & RADIX_TREE_MAP_MASK),
355 index * IDA_BITMAP_BITS,
356 (index + 1) * IDA_BITMAP_BITS - 1);
357 for (i = 0; i < IDA_BITMAP_LONGS; i++)
358 pr_cont(" %lx", bitmap->bitmap[i]);
359 pr_cont("\n");
360 }
361}
362
363static void ida_dump(struct ida *ida)
364{
365 struct radix_tree_root *root = &ida->ida_rt;
366 pr_debug("ida: %p node %p free %d\n", ida, root->rnode,
367 root->gfp_mask >> ROOT_TAG_SHIFT);
368 dump_ida_node(root->rnode, 0);
369}
283#endif 370#endif
284 371
285/* 372/*
@@ -287,13 +374,12 @@ static void radix_tree_dump(struct radix_tree_root *root)
287 * that the caller has pinned this thread of control to the current CPU. 374 * that the caller has pinned this thread of control to the current CPU.
288 */ 375 */
289static struct radix_tree_node * 376static struct radix_tree_node *
290radix_tree_node_alloc(struct radix_tree_root *root, 377radix_tree_node_alloc(gfp_t gfp_mask, struct radix_tree_node *parent,
291 struct radix_tree_node *parent, 378 struct radix_tree_root *root,
292 unsigned int shift, unsigned int offset, 379 unsigned int shift, unsigned int offset,
293 unsigned int count, unsigned int exceptional) 380 unsigned int count, unsigned int exceptional)
294{ 381{
295 struct radix_tree_node *ret = NULL; 382 struct radix_tree_node *ret = NULL;
296 gfp_t gfp_mask = root_gfp_mask(root);
297 383
298 /* 384 /*
299 * Preload code isn't irq safe and it doesn't make sense to use 385 * Preload code isn't irq safe and it doesn't make sense to use
@@ -321,8 +407,7 @@ radix_tree_node_alloc(struct radix_tree_root *root,
321 rtp = this_cpu_ptr(&radix_tree_preloads); 407 rtp = this_cpu_ptr(&radix_tree_preloads);
322 if (rtp->nr) { 408 if (rtp->nr) {
323 ret = rtp->nodes; 409 ret = rtp->nodes;
324 rtp->nodes = ret->private_data; 410 rtp->nodes = ret->parent;
325 ret->private_data = NULL;
326 rtp->nr--; 411 rtp->nr--;
327 } 412 }
328 /* 413 /*
@@ -336,11 +421,12 @@ radix_tree_node_alloc(struct radix_tree_root *root,
336out: 421out:
337 BUG_ON(radix_tree_is_internal_node(ret)); 422 BUG_ON(radix_tree_is_internal_node(ret));
338 if (ret) { 423 if (ret) {
339 ret->parent = parent;
340 ret->shift = shift; 424 ret->shift = shift;
341 ret->offset = offset; 425 ret->offset = offset;
342 ret->count = count; 426 ret->count = count;
343 ret->exceptional = exceptional; 427 ret->exceptional = exceptional;
428 ret->parent = parent;
429 ret->root = root;
344 } 430 }
345 return ret; 431 return ret;
346} 432}
@@ -399,7 +485,7 @@ static int __radix_tree_preload(gfp_t gfp_mask, unsigned nr)
399 preempt_disable(); 485 preempt_disable();
400 rtp = this_cpu_ptr(&radix_tree_preloads); 486 rtp = this_cpu_ptr(&radix_tree_preloads);
401 if (rtp->nr < nr) { 487 if (rtp->nr < nr) {
402 node->private_data = rtp->nodes; 488 node->parent = rtp->nodes;
403 rtp->nodes = node; 489 rtp->nodes = node;
404 rtp->nr++; 490 rtp->nr++;
405 } else { 491 } else {
@@ -510,7 +596,7 @@ int radix_tree_maybe_preload_order(gfp_t gfp_mask, int order)
510 return __radix_tree_preload(gfp_mask, nr_nodes); 596 return __radix_tree_preload(gfp_mask, nr_nodes);
511} 597}
512 598
513static unsigned radix_tree_load_root(struct radix_tree_root *root, 599static unsigned radix_tree_load_root(const struct radix_tree_root *root,
514 struct radix_tree_node **nodep, unsigned long *maxindex) 600 struct radix_tree_node **nodep, unsigned long *maxindex)
515{ 601{
516 struct radix_tree_node *node = rcu_dereference_raw(root->rnode); 602 struct radix_tree_node *node = rcu_dereference_raw(root->rnode);
@@ -530,10 +616,10 @@ static unsigned radix_tree_load_root(struct radix_tree_root *root,
530/* 616/*
531 * Extend a radix tree so it can store key @index. 617 * Extend a radix tree so it can store key @index.
532 */ 618 */
533static int radix_tree_extend(struct radix_tree_root *root, 619static int radix_tree_extend(struct radix_tree_root *root, gfp_t gfp,
534 unsigned long index, unsigned int shift) 620 unsigned long index, unsigned int shift)
535{ 621{
536 struct radix_tree_node *slot; 622 void *entry;
537 unsigned int maxshift; 623 unsigned int maxshift;
538 int tag; 624 int tag;
539 625
@@ -542,32 +628,44 @@ static int radix_tree_extend(struct radix_tree_root *root,
542 while (index > shift_maxindex(maxshift)) 628 while (index > shift_maxindex(maxshift))
543 maxshift += RADIX_TREE_MAP_SHIFT; 629 maxshift += RADIX_TREE_MAP_SHIFT;
544 630
545 slot = root->rnode; 631 entry = rcu_dereference_raw(root->rnode);
546 if (!slot) 632 if (!entry && (!is_idr(root) || root_tag_get(root, IDR_FREE)))
547 goto out; 633 goto out;
548 634
549 do { 635 do {
550 struct radix_tree_node *node = radix_tree_node_alloc(root, 636 struct radix_tree_node *node = radix_tree_node_alloc(gfp, NULL,
551 NULL, shift, 0, 1, 0); 637 root, shift, 0, 1, 0);
552 if (!node) 638 if (!node)
553 return -ENOMEM; 639 return -ENOMEM;
554 640
555 /* Propagate the aggregated tag info into the new root */ 641 if (is_idr(root)) {
556 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) { 642 all_tag_set(node, IDR_FREE);
557 if (root_tag_get(root, tag)) 643 if (!root_tag_get(root, IDR_FREE)) {
558 tag_set(node, tag, 0); 644 tag_clear(node, IDR_FREE, 0);
645 root_tag_set(root, IDR_FREE);
646 }
647 } else {
648 /* Propagate the aggregated tag info to the new child */
649 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) {
650 if (root_tag_get(root, tag))
651 tag_set(node, tag, 0);
652 }
559 } 653 }
560 654
561 BUG_ON(shift > BITS_PER_LONG); 655 BUG_ON(shift > BITS_PER_LONG);
562 if (radix_tree_is_internal_node(slot)) { 656 if (radix_tree_is_internal_node(entry)) {
563 entry_to_node(slot)->parent = node; 657 entry_to_node(entry)->parent = node;
564 } else if (radix_tree_exceptional_entry(slot)) { 658 } else if (radix_tree_exceptional_entry(entry)) {
565 /* Moving an exceptional root->rnode to a node */ 659 /* Moving an exceptional root->rnode to a node */
566 node->exceptional = 1; 660 node->exceptional = 1;
567 } 661 }
568 node->slots[0] = slot; 662 /*
569 slot = node_to_entry(node); 663 * entry was already in the radix tree, so we do not need
570 rcu_assign_pointer(root->rnode, slot); 664 * rcu_assign_pointer here
665 */
666 node->slots[0] = (void __rcu *)entry;
667 entry = node_to_entry(node);
668 rcu_assign_pointer(root->rnode, entry);
571 shift += RADIX_TREE_MAP_SHIFT; 669 shift += RADIX_TREE_MAP_SHIFT;
572 } while (shift <= maxshift); 670 } while (shift <= maxshift);
573out: 671out:
@@ -578,12 +676,14 @@ out:
578 * radix_tree_shrink - shrink radix tree to minimum height 676 * radix_tree_shrink - shrink radix tree to minimum height
579 * @root radix tree root 677 * @root radix tree root
580 */ 678 */
581static inline void radix_tree_shrink(struct radix_tree_root *root, 679static inline bool radix_tree_shrink(struct radix_tree_root *root,
582 radix_tree_update_node_t update_node, 680 radix_tree_update_node_t update_node,
583 void *private) 681 void *private)
584{ 682{
683 bool shrunk = false;
684
585 for (;;) { 685 for (;;) {
586 struct radix_tree_node *node = root->rnode; 686 struct radix_tree_node *node = rcu_dereference_raw(root->rnode);
587 struct radix_tree_node *child; 687 struct radix_tree_node *child;
588 688
589 if (!radix_tree_is_internal_node(node)) 689 if (!radix_tree_is_internal_node(node))
@@ -597,7 +697,7 @@ static inline void radix_tree_shrink(struct radix_tree_root *root,
597 */ 697 */
598 if (node->count != 1) 698 if (node->count != 1)
599 break; 699 break;
600 child = node->slots[0]; 700 child = rcu_dereference_raw(node->slots[0]);
601 if (!child) 701 if (!child)
602 break; 702 break;
603 if (!radix_tree_is_internal_node(child) && node->shift) 703 if (!radix_tree_is_internal_node(child) && node->shift)
@@ -613,7 +713,9 @@ static inline void radix_tree_shrink(struct radix_tree_root *root,
613 * (node->slots[0]), it will be safe to dereference the new 713 * (node->slots[0]), it will be safe to dereference the new
614 * one (root->rnode) as far as dependent read barriers go. 714 * one (root->rnode) as far as dependent read barriers go.
615 */ 715 */
616 root->rnode = child; 716 root->rnode = (void __rcu *)child;
717 if (is_idr(root) && !tag_get(node, IDR_FREE, 0))
718 root_tag_clear(root, IDR_FREE);
617 719
618 /* 720 /*
619 * We have a dilemma here. The node's slot[0] must not be 721 * We have a dilemma here. The node's slot[0] must not be
@@ -635,27 +737,34 @@ static inline void radix_tree_shrink(struct radix_tree_root *root,
635 */ 737 */
636 node->count = 0; 738 node->count = 0;
637 if (!radix_tree_is_internal_node(child)) { 739 if (!radix_tree_is_internal_node(child)) {
638 node->slots[0] = RADIX_TREE_RETRY; 740 node->slots[0] = (void __rcu *)RADIX_TREE_RETRY;
639 if (update_node) 741 if (update_node)
640 update_node(node, private); 742 update_node(node, private);
641 } 743 }
642 744
643 WARN_ON_ONCE(!list_empty(&node->private_list)); 745 WARN_ON_ONCE(!list_empty(&node->private_list));
644 radix_tree_node_free(node); 746 radix_tree_node_free(node);
747 shrunk = true;
645 } 748 }
749
750 return shrunk;
646} 751}
647 752
648static void delete_node(struct radix_tree_root *root, 753static bool delete_node(struct radix_tree_root *root,
649 struct radix_tree_node *node, 754 struct radix_tree_node *node,
650 radix_tree_update_node_t update_node, void *private) 755 radix_tree_update_node_t update_node, void *private)
651{ 756{
757 bool deleted = false;
758
652 do { 759 do {
653 struct radix_tree_node *parent; 760 struct radix_tree_node *parent;
654 761
655 if (node->count) { 762 if (node->count) {
656 if (node == entry_to_node(root->rnode)) 763 if (node_to_entry(node) ==
657 radix_tree_shrink(root, update_node, private); 764 rcu_dereference_raw(root->rnode))
658 return; 765 deleted |= radix_tree_shrink(root, update_node,
766 private);
767 return deleted;
659 } 768 }
660 769
661 parent = node->parent; 770 parent = node->parent;
@@ -663,15 +772,23 @@ static void delete_node(struct radix_tree_root *root,
663 parent->slots[node->offset] = NULL; 772 parent->slots[node->offset] = NULL;
664 parent->count--; 773 parent->count--;
665 } else { 774 } else {
666 root_tag_clear_all(root); 775 /*
776 * Shouldn't the tags already have all been cleared
777 * by the caller?
778 */
779 if (!is_idr(root))
780 root_tag_clear_all(root);
667 root->rnode = NULL; 781 root->rnode = NULL;
668 } 782 }
669 783
670 WARN_ON_ONCE(!list_empty(&node->private_list)); 784 WARN_ON_ONCE(!list_empty(&node->private_list));
671 radix_tree_node_free(node); 785 radix_tree_node_free(node);
786 deleted = true;
672 787
673 node = parent; 788 node = parent;
674 } while (node); 789 } while (node);
790
791 return deleted;
675} 792}
676 793
677/** 794/**
@@ -693,13 +810,14 @@ static void delete_node(struct radix_tree_root *root,
693 */ 810 */
694int __radix_tree_create(struct radix_tree_root *root, unsigned long index, 811int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
695 unsigned order, struct radix_tree_node **nodep, 812 unsigned order, struct radix_tree_node **nodep,
696 void ***slotp) 813 void __rcu ***slotp)
697{ 814{
698 struct radix_tree_node *node = NULL, *child; 815 struct radix_tree_node *node = NULL, *child;
699 void **slot = (void **)&root->rnode; 816 void __rcu **slot = (void __rcu **)&root->rnode;
700 unsigned long maxindex; 817 unsigned long maxindex;
701 unsigned int shift, offset = 0; 818 unsigned int shift, offset = 0;
702 unsigned long max = index | ((1UL << order) - 1); 819 unsigned long max = index | ((1UL << order) - 1);
820 gfp_t gfp = root_gfp_mask(root);
703 821
704 shift = radix_tree_load_root(root, &child, &maxindex); 822 shift = radix_tree_load_root(root, &child, &maxindex);
705 823
@@ -707,18 +825,18 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
707 if (order > 0 && max == ((1UL << order) - 1)) 825 if (order > 0 && max == ((1UL << order) - 1))
708 max++; 826 max++;
709 if (max > maxindex) { 827 if (max > maxindex) {
710 int error = radix_tree_extend(root, max, shift); 828 int error = radix_tree_extend(root, gfp, max, shift);
711 if (error < 0) 829 if (error < 0)
712 return error; 830 return error;
713 shift = error; 831 shift = error;
714 child = root->rnode; 832 child = rcu_dereference_raw(root->rnode);
715 } 833 }
716 834
717 while (shift > order) { 835 while (shift > order) {
718 shift -= RADIX_TREE_MAP_SHIFT; 836 shift -= RADIX_TREE_MAP_SHIFT;
719 if (child == NULL) { 837 if (child == NULL) {
720 /* Have to add a child node. */ 838 /* Have to add a child node. */
721 child = radix_tree_node_alloc(root, node, shift, 839 child = radix_tree_node_alloc(gfp, node, root, shift,
722 offset, 0, 0); 840 offset, 0, 0);
723 if (!child) 841 if (!child)
724 return -ENOMEM; 842 return -ENOMEM;
@@ -741,7 +859,6 @@ int __radix_tree_create(struct radix_tree_root *root, unsigned long index,
741 return 0; 859 return 0;
742} 860}
743 861
744#ifdef CONFIG_RADIX_TREE_MULTIORDER
745/* 862/*
746 * Free any nodes below this node. The tree is presumed to not need 863 * Free any nodes below this node. The tree is presumed to not need
747 * shrinking, and any user data in the tree is presumed to not need a 864 * shrinking, and any user data in the tree is presumed to not need a
@@ -757,7 +874,7 @@ static void radix_tree_free_nodes(struct radix_tree_node *node)
757 struct radix_tree_node *child = entry_to_node(node); 874 struct radix_tree_node *child = entry_to_node(node);
758 875
759 for (;;) { 876 for (;;) {
760 void *entry = child->slots[offset]; 877 void *entry = rcu_dereference_raw(child->slots[offset]);
761 if (radix_tree_is_internal_node(entry) && 878 if (radix_tree_is_internal_node(entry) &&
762 !is_sibling_entry(child, entry)) { 879 !is_sibling_entry(child, entry)) {
763 child = entry_to_node(entry); 880 child = entry_to_node(entry);
@@ -777,8 +894,9 @@ static void radix_tree_free_nodes(struct radix_tree_node *node)
777 } 894 }
778} 895}
779 896
780static inline int insert_entries(struct radix_tree_node *node, void **slot, 897#ifdef CONFIG_RADIX_TREE_MULTIORDER
781 void *item, unsigned order, bool replace) 898static inline int insert_entries(struct radix_tree_node *node,
899 void __rcu **slot, void *item, unsigned order, bool replace)
782{ 900{
783 struct radix_tree_node *child; 901 struct radix_tree_node *child;
784 unsigned i, n, tag, offset, tags = 0; 902 unsigned i, n, tag, offset, tags = 0;
@@ -813,7 +931,7 @@ static inline int insert_entries(struct radix_tree_node *node, void **slot,
813 } 931 }
814 932
815 for (i = 0; i < n; i++) { 933 for (i = 0; i < n; i++) {
816 struct radix_tree_node *old = slot[i]; 934 struct radix_tree_node *old = rcu_dereference_raw(slot[i]);
817 if (i) { 935 if (i) {
818 rcu_assign_pointer(slot[i], child); 936 rcu_assign_pointer(slot[i], child);
819 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) 937 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
@@ -840,8 +958,8 @@ static inline int insert_entries(struct radix_tree_node *node, void **slot,
840 return n; 958 return n;
841} 959}
842#else 960#else
843static inline int insert_entries(struct radix_tree_node *node, void **slot, 961static inline int insert_entries(struct radix_tree_node *node,
844 void *item, unsigned order, bool replace) 962 void __rcu **slot, void *item, unsigned order, bool replace)
845{ 963{
846 if (*slot) 964 if (*slot)
847 return -EEXIST; 965 return -EEXIST;
@@ -868,7 +986,7 @@ int __radix_tree_insert(struct radix_tree_root *root, unsigned long index,
868 unsigned order, void *item) 986 unsigned order, void *item)
869{ 987{
870 struct radix_tree_node *node; 988 struct radix_tree_node *node;
871 void **slot; 989 void __rcu **slot;
872 int error; 990 int error;
873 991
874 BUG_ON(radix_tree_is_internal_node(item)); 992 BUG_ON(radix_tree_is_internal_node(item));
@@ -908,16 +1026,17 @@ EXPORT_SYMBOL(__radix_tree_insert);
908 * allocated and @root->rnode is used as a direct slot instead of 1026 * allocated and @root->rnode is used as a direct slot instead of
909 * pointing to a node, in which case *@nodep will be NULL. 1027 * pointing to a node, in which case *@nodep will be NULL.
910 */ 1028 */
911void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index, 1029void *__radix_tree_lookup(const struct radix_tree_root *root,
912 struct radix_tree_node **nodep, void ***slotp) 1030 unsigned long index, struct radix_tree_node **nodep,
1031 void __rcu ***slotp)
913{ 1032{
914 struct radix_tree_node *node, *parent; 1033 struct radix_tree_node *node, *parent;
915 unsigned long maxindex; 1034 unsigned long maxindex;
916 void **slot; 1035 void __rcu **slot;
917 1036
918 restart: 1037 restart:
919 parent = NULL; 1038 parent = NULL;
920 slot = (void **)&root->rnode; 1039 slot = (void __rcu **)&root->rnode;
921 radix_tree_load_root(root, &node, &maxindex); 1040 radix_tree_load_root(root, &node, &maxindex);
922 if (index > maxindex) 1041 if (index > maxindex)
923 return NULL; 1042 return NULL;
@@ -952,9 +1071,10 @@ void *__radix_tree_lookup(struct radix_tree_root *root, unsigned long index,
952 * exclusive from other writers. Any dereference of the slot must be done 1071 * exclusive from other writers. Any dereference of the slot must be done
953 * using radix_tree_deref_slot. 1072 * using radix_tree_deref_slot.
954 */ 1073 */
955void **radix_tree_lookup_slot(struct radix_tree_root *root, unsigned long index) 1074void __rcu **radix_tree_lookup_slot(const struct radix_tree_root *root,
1075 unsigned long index)
956{ 1076{
957 void **slot; 1077 void __rcu **slot;
958 1078
959 if (!__radix_tree_lookup(root, index, NULL, &slot)) 1079 if (!__radix_tree_lookup(root, index, NULL, &slot))
960 return NULL; 1080 return NULL;
@@ -974,75 +1094,76 @@ EXPORT_SYMBOL(radix_tree_lookup_slot);
974 * them safely). No RCU barriers are required to access or modify the 1094 * them safely). No RCU barriers are required to access or modify the
975 * returned item, however. 1095 * returned item, however.
976 */ 1096 */
977void *radix_tree_lookup(struct radix_tree_root *root, unsigned long index) 1097void *radix_tree_lookup(const struct radix_tree_root *root, unsigned long index)
978{ 1098{
979 return __radix_tree_lookup(root, index, NULL, NULL); 1099 return __radix_tree_lookup(root, index, NULL, NULL);
980} 1100}
981EXPORT_SYMBOL(radix_tree_lookup); 1101EXPORT_SYMBOL(radix_tree_lookup);
982 1102
983static inline int slot_count(struct radix_tree_node *node, 1103static inline void replace_sibling_entries(struct radix_tree_node *node,
984 void **slot) 1104 void __rcu **slot, int count, int exceptional)
985{ 1105{
986 int n = 1;
987#ifdef CONFIG_RADIX_TREE_MULTIORDER 1106#ifdef CONFIG_RADIX_TREE_MULTIORDER
988 void *ptr = node_to_entry(slot); 1107 void *ptr = node_to_entry(slot);
989 unsigned offset = get_slot_offset(node, slot); 1108 unsigned offset = get_slot_offset(node, slot) + 1;
990 int i;
991 1109
992 for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) { 1110 while (offset < RADIX_TREE_MAP_SIZE) {
993 if (node->slots[offset + i] != ptr) 1111 if (rcu_dereference_raw(node->slots[offset]) != ptr)
994 break; 1112 break;
995 n++; 1113 if (count < 0) {
1114 node->slots[offset] = NULL;
1115 node->count--;
1116 }
1117 node->exceptional += exceptional;
1118 offset++;
996 } 1119 }
997#endif 1120#endif
998 return n;
999} 1121}
1000 1122
1001static void replace_slot(struct radix_tree_root *root, 1123static void replace_slot(void __rcu **slot, void *item,
1002 struct radix_tree_node *node, 1124 struct radix_tree_node *node, int count, int exceptional)
1003 void **slot, void *item,
1004 bool warn_typeswitch)
1005{ 1125{
1006 void *old = rcu_dereference_raw(*slot); 1126 if (WARN_ON_ONCE(radix_tree_is_internal_node(item)))
1007 int count, exceptional; 1127 return;
1008
1009 WARN_ON_ONCE(radix_tree_is_internal_node(item));
1010
1011 count = !!item - !!old;
1012 exceptional = !!radix_tree_exceptional_entry(item) -
1013 !!radix_tree_exceptional_entry(old);
1014
1015 WARN_ON_ONCE(warn_typeswitch && (count || exceptional));
1016 1128
1017 if (node) { 1129 if (node && (count || exceptional)) {
1018 node->count += count; 1130 node->count += count;
1019 if (exceptional) { 1131 node->exceptional += exceptional;
1020 exceptional *= slot_count(node, slot); 1132 replace_sibling_entries(node, slot, count, exceptional);
1021 node->exceptional += exceptional;
1022 }
1023 } 1133 }
1024 1134
1025 rcu_assign_pointer(*slot, item); 1135 rcu_assign_pointer(*slot, item);
1026} 1136}
1027 1137
1028static inline void delete_sibling_entries(struct radix_tree_node *node, 1138static bool node_tag_get(const struct radix_tree_root *root,
1029 void **slot) 1139 const struct radix_tree_node *node,
1140 unsigned int tag, unsigned int offset)
1030{ 1141{
1031#ifdef CONFIG_RADIX_TREE_MULTIORDER 1142 if (node)
1032 bool exceptional = radix_tree_exceptional_entry(*slot); 1143 return tag_get(node, tag, offset);
1033 void *ptr = node_to_entry(slot); 1144 return root_tag_get(root, tag);
1034 unsigned offset = get_slot_offset(node, slot); 1145}
1035 int i;
1036 1146
1037 for (i = 1; offset + i < RADIX_TREE_MAP_SIZE; i++) { 1147/*
1038 if (node->slots[offset + i] != ptr) 1148 * IDR users want to be able to store NULL in the tree, so if the slot isn't
1039 break; 1149 * free, don't adjust the count, even if it's transitioning between NULL and
1040 node->slots[offset + i] = NULL; 1150 * non-NULL. For the IDA, we mark slots as being IDR_FREE while they still
1041 node->count--; 1151 * have empty bits, but it only stores NULL in slots when they're being
1042 if (exceptional) 1152 * deleted.
1043 node->exceptional--; 1153 */
1154static int calculate_count(struct radix_tree_root *root,
1155 struct radix_tree_node *node, void __rcu **slot,
1156 void *item, void *old)
1157{
1158 if (is_idr(root)) {
1159 unsigned offset = get_slot_offset(node, slot);
1160 bool free = node_tag_get(root, node, IDR_FREE, offset);
1161 if (!free)
1162 return 0;
1163 if (!old)
1164 return 1;
1044 } 1165 }
1045#endif 1166 return !!item - !!old;
1046} 1167}
1047 1168
1048/** 1169/**
@@ -1059,18 +1180,22 @@ static inline void delete_sibling_entries(struct radix_tree_node *node,
1059 */ 1180 */
1060void __radix_tree_replace(struct radix_tree_root *root, 1181void __radix_tree_replace(struct radix_tree_root *root,
1061 struct radix_tree_node *node, 1182 struct radix_tree_node *node,
1062 void **slot, void *item, 1183 void __rcu **slot, void *item,
1063 radix_tree_update_node_t update_node, void *private) 1184 radix_tree_update_node_t update_node, void *private)
1064{ 1185{
1065 if (!item) 1186 void *old = rcu_dereference_raw(*slot);
1066 delete_sibling_entries(node, slot); 1187 int exceptional = !!radix_tree_exceptional_entry(item) -
1188 !!radix_tree_exceptional_entry(old);
1189 int count = calculate_count(root, node, slot, item, old);
1190
1067 /* 1191 /*
1068 * This function supports replacing exceptional entries and 1192 * This function supports replacing exceptional entries and
1069 * deleting entries, but that needs accounting against the 1193 * deleting entries, but that needs accounting against the
1070 * node unless the slot is root->rnode. 1194 * node unless the slot is root->rnode.
1071 */ 1195 */
1072 replace_slot(root, node, slot, item, 1196 WARN_ON_ONCE(!node && (slot != (void __rcu **)&root->rnode) &&
1073 !node && slot != (void **)&root->rnode); 1197 (count || exceptional));
1198 replace_slot(slot, item, node, count, exceptional);
1074 1199
1075 if (!node) 1200 if (!node)
1076 return; 1201 return;
@@ -1098,9 +1223,9 @@ void __radix_tree_replace(struct radix_tree_root *root,
1098 * radix_tree_iter_replace(). 1223 * radix_tree_iter_replace().
1099 */ 1224 */
1100void radix_tree_replace_slot(struct radix_tree_root *root, 1225void radix_tree_replace_slot(struct radix_tree_root *root,
1101 void **slot, void *item) 1226 void __rcu **slot, void *item)
1102{ 1227{
1103 replace_slot(root, NULL, slot, item, true); 1228 __radix_tree_replace(root, NULL, slot, item, NULL, NULL);
1104} 1229}
1105EXPORT_SYMBOL(radix_tree_replace_slot); 1230EXPORT_SYMBOL(radix_tree_replace_slot);
1106 1231
@@ -1114,7 +1239,8 @@ EXPORT_SYMBOL(radix_tree_replace_slot);
1114 * Caller must hold tree write locked across split and replacement. 1239 * Caller must hold tree write locked across split and replacement.
1115 */ 1240 */
1116void radix_tree_iter_replace(struct radix_tree_root *root, 1241void radix_tree_iter_replace(struct radix_tree_root *root,
1117 const struct radix_tree_iter *iter, void **slot, void *item) 1242 const struct radix_tree_iter *iter,
1243 void __rcu **slot, void *item)
1118{ 1244{
1119 __radix_tree_replace(root, iter->node, slot, item, NULL, NULL); 1245 __radix_tree_replace(root, iter->node, slot, item, NULL, NULL);
1120} 1246}
@@ -1138,7 +1264,7 @@ int radix_tree_join(struct radix_tree_root *root, unsigned long index,
1138 unsigned order, void *item) 1264 unsigned order, void *item)
1139{ 1265{
1140 struct radix_tree_node *node; 1266 struct radix_tree_node *node;
1141 void **slot; 1267 void __rcu **slot;
1142 int error; 1268 int error;
1143 1269
1144 BUG_ON(radix_tree_is_internal_node(item)); 1270 BUG_ON(radix_tree_is_internal_node(item));
@@ -1173,9 +1299,10 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index,
1173 unsigned order) 1299 unsigned order)
1174{ 1300{
1175 struct radix_tree_node *parent, *node, *child; 1301 struct radix_tree_node *parent, *node, *child;
1176 void **slot; 1302 void __rcu **slot;
1177 unsigned int offset, end; 1303 unsigned int offset, end;
1178 unsigned n, tag, tags = 0; 1304 unsigned n, tag, tags = 0;
1305 gfp_t gfp = root_gfp_mask(root);
1179 1306
1180 if (!__radix_tree_lookup(root, index, &parent, &slot)) 1307 if (!__radix_tree_lookup(root, index, &parent, &slot))
1181 return -ENOENT; 1308 return -ENOENT;
@@ -1189,7 +1316,8 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index,
1189 tags |= 1 << tag; 1316 tags |= 1 << tag;
1190 1317
1191 for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) { 1318 for (end = offset + 1; end < RADIX_TREE_MAP_SIZE; end++) {
1192 if (!is_sibling_entry(parent, parent->slots[end])) 1319 if (!is_sibling_entry(parent,
1320 rcu_dereference_raw(parent->slots[end])))
1193 break; 1321 break;
1194 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) 1322 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1195 if (tags & (1 << tag)) 1323 if (tags & (1 << tag))
@@ -1213,14 +1341,15 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index,
1213 1341
1214 for (;;) { 1342 for (;;) {
1215 if (node->shift > order) { 1343 if (node->shift > order) {
1216 child = radix_tree_node_alloc(root, node, 1344 child = radix_tree_node_alloc(gfp, node, root,
1217 node->shift - RADIX_TREE_MAP_SHIFT, 1345 node->shift - RADIX_TREE_MAP_SHIFT,
1218 offset, 0, 0); 1346 offset, 0, 0);
1219 if (!child) 1347 if (!child)
1220 goto nomem; 1348 goto nomem;
1221 if (node != parent) { 1349 if (node != parent) {
1222 node->count++; 1350 node->count++;
1223 node->slots[offset] = node_to_entry(child); 1351 rcu_assign_pointer(node->slots[offset],
1352 node_to_entry(child));
1224 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) 1353 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1225 if (tags & (1 << tag)) 1354 if (tags & (1 << tag))
1226 tag_set(node, tag, offset); 1355 tag_set(node, tag, offset);
@@ -1262,6 +1391,22 @@ int radix_tree_split(struct radix_tree_root *root, unsigned long index,
1262} 1391}
1263#endif 1392#endif
1264 1393
1394static void node_tag_set(struct radix_tree_root *root,
1395 struct radix_tree_node *node,
1396 unsigned int tag, unsigned int offset)
1397{
1398 while (node) {
1399 if (tag_get(node, tag, offset))
1400 return;
1401 tag_set(node, tag, offset);
1402 offset = node->offset;
1403 node = node->parent;
1404 }
1405
1406 if (!root_tag_get(root, tag))
1407 root_tag_set(root, tag);
1408}
1409
1265/** 1410/**
1266 * radix_tree_tag_set - set a tag on a radix tree node 1411 * radix_tree_tag_set - set a tag on a radix tree node
1267 * @root: radix tree root 1412 * @root: radix tree root
@@ -1303,6 +1448,18 @@ void *radix_tree_tag_set(struct radix_tree_root *root,
1303} 1448}
1304EXPORT_SYMBOL(radix_tree_tag_set); 1449EXPORT_SYMBOL(radix_tree_tag_set);
1305 1450
1451/**
1452 * radix_tree_iter_tag_set - set a tag on the current iterator entry
1453 * @root: radix tree root
1454 * @iter: iterator state
1455 * @tag: tag to set
1456 */
1457void radix_tree_iter_tag_set(struct radix_tree_root *root,
1458 const struct radix_tree_iter *iter, unsigned int tag)
1459{
1460 node_tag_set(root, iter->node, tag, iter_offset(iter));
1461}
1462
1306static void node_tag_clear(struct radix_tree_root *root, 1463static void node_tag_clear(struct radix_tree_root *root,
1307 struct radix_tree_node *node, 1464 struct radix_tree_node *node,
1308 unsigned int tag, unsigned int offset) 1465 unsigned int tag, unsigned int offset)
@@ -1323,34 +1480,6 @@ static void node_tag_clear(struct radix_tree_root *root,
1323 root_tag_clear(root, tag); 1480 root_tag_clear(root, tag);
1324} 1481}
1325 1482
1326static void node_tag_set(struct radix_tree_root *root,
1327 struct radix_tree_node *node,
1328 unsigned int tag, unsigned int offset)
1329{
1330 while (node) {
1331 if (tag_get(node, tag, offset))
1332 return;
1333 tag_set(node, tag, offset);
1334 offset = node->offset;
1335 node = node->parent;
1336 }
1337
1338 if (!root_tag_get(root, tag))
1339 root_tag_set(root, tag);
1340}
1341
1342/**
1343 * radix_tree_iter_tag_set - set a tag on the current iterator entry
1344 * @root: radix tree root
1345 * @iter: iterator state
1346 * @tag: tag to set
1347 */
1348void radix_tree_iter_tag_set(struct radix_tree_root *root,
1349 const struct radix_tree_iter *iter, unsigned int tag)
1350{
1351 node_tag_set(root, iter->node, tag, iter_offset(iter));
1352}
1353
1354/** 1483/**
1355 * radix_tree_tag_clear - clear a tag on a radix tree node 1484 * radix_tree_tag_clear - clear a tag on a radix tree node
1356 * @root: radix tree root 1485 * @root: radix tree root
@@ -1391,6 +1520,18 @@ void *radix_tree_tag_clear(struct radix_tree_root *root,
1391EXPORT_SYMBOL(radix_tree_tag_clear); 1520EXPORT_SYMBOL(radix_tree_tag_clear);
1392 1521
1393/** 1522/**
1523 * radix_tree_iter_tag_clear - clear a tag on the current iterator entry
1524 * @root: radix tree root
1525 * @iter: iterator state
1526 * @tag: tag to clear
1527 */
1528void radix_tree_iter_tag_clear(struct radix_tree_root *root,
1529 const struct radix_tree_iter *iter, unsigned int tag)
1530{
1531 node_tag_clear(root, iter->node, tag, iter_offset(iter));
1532}
1533
1534/**
1394 * radix_tree_tag_get - get a tag on a radix tree node 1535 * radix_tree_tag_get - get a tag on a radix tree node
1395 * @root: radix tree root 1536 * @root: radix tree root
1396 * @index: index key 1537 * @index: index key
@@ -1405,7 +1546,7 @@ EXPORT_SYMBOL(radix_tree_tag_clear);
1405 * the RCU lock is held, unless tag modification and node deletion are excluded 1546 * the RCU lock is held, unless tag modification and node deletion are excluded
1406 * from concurrency. 1547 * from concurrency.
1407 */ 1548 */
1408int radix_tree_tag_get(struct radix_tree_root *root, 1549int radix_tree_tag_get(const struct radix_tree_root *root,
1409 unsigned long index, unsigned int tag) 1550 unsigned long index, unsigned int tag)
1410{ 1551{
1411 struct radix_tree_node *node, *parent; 1552 struct radix_tree_node *node, *parent;
@@ -1417,8 +1558,6 @@ int radix_tree_tag_get(struct radix_tree_root *root,
1417 radix_tree_load_root(root, &node, &maxindex); 1558 radix_tree_load_root(root, &node, &maxindex);
1418 if (index > maxindex) 1559 if (index > maxindex)
1419 return 0; 1560 return 0;
1420 if (node == NULL)
1421 return 0;
1422 1561
1423 while (radix_tree_is_internal_node(node)) { 1562 while (radix_tree_is_internal_node(node)) {
1424 unsigned offset; 1563 unsigned offset;
@@ -1426,8 +1565,6 @@ int radix_tree_tag_get(struct radix_tree_root *root,
1426 parent = entry_to_node(node); 1565 parent = entry_to_node(node);
1427 offset = radix_tree_descend(parent, &node, index); 1566 offset = radix_tree_descend(parent, &node, index);
1428 1567
1429 if (!node)
1430 return 0;
1431 if (!tag_get(parent, tag, offset)) 1568 if (!tag_get(parent, tag, offset))
1432 return 0; 1569 return 0;
1433 if (node == RADIX_TREE_RETRY) 1570 if (node == RADIX_TREE_RETRY)
@@ -1454,6 +1591,11 @@ static void set_iter_tags(struct radix_tree_iter *iter,
1454 unsigned tag_long = offset / BITS_PER_LONG; 1591 unsigned tag_long = offset / BITS_PER_LONG;
1455 unsigned tag_bit = offset % BITS_PER_LONG; 1592 unsigned tag_bit = offset % BITS_PER_LONG;
1456 1593
1594 if (!node) {
1595 iter->tags = 1;
1596 return;
1597 }
1598
1457 iter->tags = node->tags[tag][tag_long] >> tag_bit; 1599 iter->tags = node->tags[tag][tag_long] >> tag_bit;
1458 1600
1459 /* This never happens if RADIX_TREE_TAG_LONGS == 1 */ 1601 /* This never happens if RADIX_TREE_TAG_LONGS == 1 */
@@ -1468,8 +1610,8 @@ static void set_iter_tags(struct radix_tree_iter *iter,
1468} 1610}
1469 1611
1470#ifdef CONFIG_RADIX_TREE_MULTIORDER 1612#ifdef CONFIG_RADIX_TREE_MULTIORDER
1471static void **skip_siblings(struct radix_tree_node **nodep, 1613static void __rcu **skip_siblings(struct radix_tree_node **nodep,
1472 void **slot, struct radix_tree_iter *iter) 1614 void __rcu **slot, struct radix_tree_iter *iter)
1473{ 1615{
1474 void *sib = node_to_entry(slot - 1); 1616 void *sib = node_to_entry(slot - 1);
1475 1617
@@ -1486,8 +1628,8 @@ static void **skip_siblings(struct radix_tree_node **nodep,
1486 return NULL; 1628 return NULL;
1487} 1629}
1488 1630
1489void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter, 1631void __rcu **__radix_tree_next_slot(void __rcu **slot,
1490 unsigned flags) 1632 struct radix_tree_iter *iter, unsigned flags)
1491{ 1633{
1492 unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; 1634 unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
1493 struct radix_tree_node *node = rcu_dereference_raw(*slot); 1635 struct radix_tree_node *node = rcu_dereference_raw(*slot);
@@ -1540,20 +1682,20 @@ void ** __radix_tree_next_slot(void **slot, struct radix_tree_iter *iter,
1540} 1682}
1541EXPORT_SYMBOL(__radix_tree_next_slot); 1683EXPORT_SYMBOL(__radix_tree_next_slot);
1542#else 1684#else
1543static void **skip_siblings(struct radix_tree_node **nodep, 1685static void __rcu **skip_siblings(struct radix_tree_node **nodep,
1544 void **slot, struct radix_tree_iter *iter) 1686 void __rcu **slot, struct radix_tree_iter *iter)
1545{ 1687{
1546 return slot; 1688 return slot;
1547} 1689}
1548#endif 1690#endif
1549 1691
1550void **radix_tree_iter_resume(void **slot, struct radix_tree_iter *iter) 1692void __rcu **radix_tree_iter_resume(void __rcu **slot,
1693 struct radix_tree_iter *iter)
1551{ 1694{
1552 struct radix_tree_node *node; 1695 struct radix_tree_node *node;
1553 1696
1554 slot++; 1697 slot++;
1555 iter->index = __radix_tree_iter_add(iter, 1); 1698 iter->index = __radix_tree_iter_add(iter, 1);
1556 node = rcu_dereference_raw(*slot);
1557 skip_siblings(&node, slot, iter); 1699 skip_siblings(&node, slot, iter);
1558 iter->next_index = iter->index; 1700 iter->next_index = iter->index;
1559 iter->tags = 0; 1701 iter->tags = 0;
@@ -1569,7 +1711,7 @@ EXPORT_SYMBOL(radix_tree_iter_resume);
1569 * @flags: RADIX_TREE_ITER_* flags and tag index 1711 * @flags: RADIX_TREE_ITER_* flags and tag index
1570 * Returns: pointer to chunk first slot, or NULL if iteration is over 1712 * Returns: pointer to chunk first slot, or NULL if iteration is over
1571 */ 1713 */
1572void **radix_tree_next_chunk(struct radix_tree_root *root, 1714void __rcu **radix_tree_next_chunk(const struct radix_tree_root *root,
1573 struct radix_tree_iter *iter, unsigned flags) 1715 struct radix_tree_iter *iter, unsigned flags)
1574{ 1716{
1575 unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK; 1717 unsigned tag = flags & RADIX_TREE_ITER_TAG_MASK;
@@ -1606,7 +1748,7 @@ void **radix_tree_next_chunk(struct radix_tree_root *root,
1606 iter->tags = 1; 1748 iter->tags = 1;
1607 iter->node = NULL; 1749 iter->node = NULL;
1608 __set_iter_shift(iter, 0); 1750 __set_iter_shift(iter, 0);
1609 return (void **)&root->rnode; 1751 return (void __rcu **)&root->rnode;
1610 } 1752 }
1611 1753
1612 do { 1754 do {
@@ -1624,7 +1766,8 @@ void **radix_tree_next_chunk(struct radix_tree_root *root,
1624 offset + 1); 1766 offset + 1);
1625 else 1767 else
1626 while (++offset < RADIX_TREE_MAP_SIZE) { 1768 while (++offset < RADIX_TREE_MAP_SIZE) {
1627 void *slot = node->slots[offset]; 1769 void *slot = rcu_dereference_raw(
1770 node->slots[offset]);
1628 if (is_sibling_entry(node, slot)) 1771 if (is_sibling_entry(node, slot))
1629 continue; 1772 continue;
1630 if (slot) 1773 if (slot)
@@ -1680,11 +1823,11 @@ EXPORT_SYMBOL(radix_tree_next_chunk);
1680 * stored in 'results'. 1823 * stored in 'results'.
1681 */ 1824 */
1682unsigned int 1825unsigned int
1683radix_tree_gang_lookup(struct radix_tree_root *root, void **results, 1826radix_tree_gang_lookup(const struct radix_tree_root *root, void **results,
1684 unsigned long first_index, unsigned int max_items) 1827 unsigned long first_index, unsigned int max_items)
1685{ 1828{
1686 struct radix_tree_iter iter; 1829 struct radix_tree_iter iter;
1687 void **slot; 1830 void __rcu **slot;
1688 unsigned int ret = 0; 1831 unsigned int ret = 0;
1689 1832
1690 if (unlikely(!max_items)) 1833 if (unlikely(!max_items))
@@ -1725,12 +1868,12 @@ EXPORT_SYMBOL(radix_tree_gang_lookup);
1725 * protection, radix_tree_deref_slot may fail requiring a retry. 1868 * protection, radix_tree_deref_slot may fail requiring a retry.
1726 */ 1869 */
1727unsigned int 1870unsigned int
1728radix_tree_gang_lookup_slot(struct radix_tree_root *root, 1871radix_tree_gang_lookup_slot(const struct radix_tree_root *root,
1729 void ***results, unsigned long *indices, 1872 void __rcu ***results, unsigned long *indices,
1730 unsigned long first_index, unsigned int max_items) 1873 unsigned long first_index, unsigned int max_items)
1731{ 1874{
1732 struct radix_tree_iter iter; 1875 struct radix_tree_iter iter;
1733 void **slot; 1876 void __rcu **slot;
1734 unsigned int ret = 0; 1877 unsigned int ret = 0;
1735 1878
1736 if (unlikely(!max_items)) 1879 if (unlikely(!max_items))
@@ -1762,12 +1905,12 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_slot);
1762 * returns the number of items which were placed at *@results. 1905 * returns the number of items which were placed at *@results.
1763 */ 1906 */
1764unsigned int 1907unsigned int
1765radix_tree_gang_lookup_tag(struct radix_tree_root *root, void **results, 1908radix_tree_gang_lookup_tag(const struct radix_tree_root *root, void **results,
1766 unsigned long first_index, unsigned int max_items, 1909 unsigned long first_index, unsigned int max_items,
1767 unsigned int tag) 1910 unsigned int tag)
1768{ 1911{
1769 struct radix_tree_iter iter; 1912 struct radix_tree_iter iter;
1770 void **slot; 1913 void __rcu **slot;
1771 unsigned int ret = 0; 1914 unsigned int ret = 0;
1772 1915
1773 if (unlikely(!max_items)) 1916 if (unlikely(!max_items))
@@ -1803,12 +1946,12 @@ EXPORT_SYMBOL(radix_tree_gang_lookup_tag);
1803 * returns the number of slots which were placed at *@results. 1946 * returns the number of slots which were placed at *@results.
1804 */ 1947 */
1805unsigned int 1948unsigned int
1806radix_tree_gang_lookup_tag_slot(struct radix_tree_root *root, void ***results, 1949radix_tree_gang_lookup_tag_slot(const struct radix_tree_root *root,
1807 unsigned long first_index, unsigned int max_items, 1950 void __rcu ***results, unsigned long first_index,
1808 unsigned int tag) 1951 unsigned int max_items, unsigned int tag)
1809{ 1952{
1810 struct radix_tree_iter iter; 1953 struct radix_tree_iter iter;
1811 void **slot; 1954 void __rcu **slot;
1812 unsigned int ret = 0; 1955 unsigned int ret = 0;
1813 1956
1814 if (unlikely(!max_items)) 1957 if (unlikely(!max_items))
@@ -1843,59 +1986,83 @@ void __radix_tree_delete_node(struct radix_tree_root *root,
1843 delete_node(root, node, update_node, private); 1986 delete_node(root, node, update_node, private);
1844} 1987}
1845 1988
1989static bool __radix_tree_delete(struct radix_tree_root *root,
1990 struct radix_tree_node *node, void __rcu **slot)
1991{
1992 void *old = rcu_dereference_raw(*slot);
1993 int exceptional = radix_tree_exceptional_entry(old) ? -1 : 0;
1994 unsigned offset = get_slot_offset(node, slot);
1995 int tag;
1996
1997 if (is_idr(root))
1998 node_tag_set(root, node, IDR_FREE, offset);
1999 else
2000 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
2001 node_tag_clear(root, node, tag, offset);
2002
2003 replace_slot(slot, NULL, node, -1, exceptional);
2004 return node && delete_node(root, node, NULL, NULL);
2005}
2006
1846/** 2007/**
1847 * radix_tree_delete_item - delete an item from a radix tree 2008 * radix_tree_iter_delete - delete the entry at this iterator position
1848 * @root: radix tree root 2009 * @root: radix tree root
1849 * @index: index key 2010 * @iter: iterator state
1850 * @item: expected item 2011 * @slot: pointer to slot
1851 * 2012 *
1852 * Remove @item at @index from the radix tree rooted at @root. 2013 * Delete the entry at the position currently pointed to by the iterator.
2014 * This may result in the current node being freed; if it is, the iterator
2015 * is advanced so that it will not reference the freed memory. This
2016 * function may be called without any locking if there are no other threads
2017 * which can access this tree.
2018 */
2019void radix_tree_iter_delete(struct radix_tree_root *root,
2020 struct radix_tree_iter *iter, void __rcu **slot)
2021{
2022 if (__radix_tree_delete(root, iter->node, slot))
2023 iter->index = iter->next_index;
2024}
2025
2026/**
2027 * radix_tree_delete_item - delete an item from a radix tree
2028 * @root: radix tree root
2029 * @index: index key
2030 * @item: expected item
1853 * 2031 *
1854 * Returns the address of the deleted item, or NULL if it was not present 2032 * Remove @item at @index from the radix tree rooted at @root.
1855 * or the entry at the given @index was not @item. 2033 *
2034 * Return: the deleted entry, or %NULL if it was not present
2035 * or the entry at the given @index was not @item.
1856 */ 2036 */
1857void *radix_tree_delete_item(struct radix_tree_root *root, 2037void *radix_tree_delete_item(struct radix_tree_root *root,
1858 unsigned long index, void *item) 2038 unsigned long index, void *item)
1859{ 2039{
1860 struct radix_tree_node *node; 2040 struct radix_tree_node *node = NULL;
1861 unsigned int offset; 2041 void __rcu **slot;
1862 void **slot;
1863 void *entry; 2042 void *entry;
1864 int tag;
1865 2043
1866 entry = __radix_tree_lookup(root, index, &node, &slot); 2044 entry = __radix_tree_lookup(root, index, &node, &slot);
1867 if (!entry) 2045 if (!entry && (!is_idr(root) || node_tag_get(root, node, IDR_FREE,
2046 get_slot_offset(node, slot))))
1868 return NULL; 2047 return NULL;
1869 2048
1870 if (item && entry != item) 2049 if (item && entry != item)
1871 return NULL; 2050 return NULL;
1872 2051
1873 if (!node) { 2052 __radix_tree_delete(root, node, slot);
1874 root_tag_clear_all(root);
1875 root->rnode = NULL;
1876 return entry;
1877 }
1878
1879 offset = get_slot_offset(node, slot);
1880
1881 /* Clear all tags associated with the item to be deleted. */
1882 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1883 node_tag_clear(root, node, tag, offset);
1884
1885 __radix_tree_replace(root, node, slot, NULL, NULL, NULL);
1886 2053
1887 return entry; 2054 return entry;
1888} 2055}
1889EXPORT_SYMBOL(radix_tree_delete_item); 2056EXPORT_SYMBOL(radix_tree_delete_item);
1890 2057
1891/** 2058/**
1892 * radix_tree_delete - delete an item from a radix tree 2059 * radix_tree_delete - delete an entry from a radix tree
1893 * @root: radix tree root 2060 * @root: radix tree root
1894 * @index: index key 2061 * @index: index key
1895 * 2062 *
1896 * Remove the item at @index from the radix tree rooted at @root. 2063 * Remove the entry at @index from the radix tree rooted at @root.
1897 * 2064 *
1898 * Returns the address of the deleted item, or NULL if it was not present. 2065 * Return: The deleted entry, or %NULL if it was not present.
1899 */ 2066 */
1900void *radix_tree_delete(struct radix_tree_root *root, unsigned long index) 2067void *radix_tree_delete(struct radix_tree_root *root, unsigned long index)
1901{ 2068{
@@ -1905,15 +2072,14 @@ EXPORT_SYMBOL(radix_tree_delete);
1905 2072
1906void radix_tree_clear_tags(struct radix_tree_root *root, 2073void radix_tree_clear_tags(struct radix_tree_root *root,
1907 struct radix_tree_node *node, 2074 struct radix_tree_node *node,
1908 void **slot) 2075 void __rcu **slot)
1909{ 2076{
1910 if (node) { 2077 if (node) {
1911 unsigned int tag, offset = get_slot_offset(node, slot); 2078 unsigned int tag, offset = get_slot_offset(node, slot);
1912 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++) 2079 for (tag = 0; tag < RADIX_TREE_MAX_TAGS; tag++)
1913 node_tag_clear(root, node, tag, offset); 2080 node_tag_clear(root, node, tag, offset);
1914 } else { 2081 } else {
1915 /* Clear root node tags */ 2082 root_tag_clear_all(root);
1916 root->gfp_mask &= __GFP_BITS_MASK;
1917 } 2083 }
1918} 2084}
1919 2085
@@ -1922,12 +2088,147 @@ void radix_tree_clear_tags(struct radix_tree_root *root,
1922 * @root: radix tree root 2088 * @root: radix tree root
1923 * @tag: tag to test 2089 * @tag: tag to test
1924 */ 2090 */
1925int radix_tree_tagged(struct radix_tree_root *root, unsigned int tag) 2091int radix_tree_tagged(const struct radix_tree_root *root, unsigned int tag)
1926{ 2092{
1927 return root_tag_get(root, tag); 2093 return root_tag_get(root, tag);
1928} 2094}
1929EXPORT_SYMBOL(radix_tree_tagged); 2095EXPORT_SYMBOL(radix_tree_tagged);
1930 2096
2097/**
2098 * idr_preload - preload for idr_alloc()
2099 * @gfp_mask: allocation mask to use for preloading
2100 *
2101 * Preallocate memory to use for the next call to idr_alloc(). This function
2102 * returns with preemption disabled. It will be enabled by idr_preload_end().
2103 */
2104void idr_preload(gfp_t gfp_mask)
2105{
2106 __radix_tree_preload(gfp_mask, IDR_PRELOAD_SIZE);
2107}
2108EXPORT_SYMBOL(idr_preload);
2109
2110/**
2111 * ida_pre_get - reserve resources for ida allocation
2112 * @ida: ida handle
2113 * @gfp: memory allocation flags
2114 *
2115 * This function should be called before calling ida_get_new_above(). If it
2116 * is unable to allocate memory, it will return %0. On success, it returns %1.
2117 */
2118int ida_pre_get(struct ida *ida, gfp_t gfp)
2119{
2120 __radix_tree_preload(gfp, IDA_PRELOAD_SIZE);
2121 /*
2122 * The IDA API has no preload_end() equivalent. Instead,
2123 * ida_get_new() can return -EAGAIN, prompting the caller
2124 * to return to the ida_pre_get() step.
2125 */
2126 preempt_enable();
2127
2128 if (!this_cpu_read(ida_bitmap)) {
2129 struct ida_bitmap *bitmap = kmalloc(sizeof(*bitmap), gfp);
2130 if (!bitmap)
2131 return 0;
2132 bitmap = this_cpu_cmpxchg(ida_bitmap, NULL, bitmap);
2133 kfree(bitmap);
2134 }
2135
2136 return 1;
2137}
2138EXPORT_SYMBOL(ida_pre_get);
2139
2140void __rcu **idr_get_free(struct radix_tree_root *root,
2141 struct radix_tree_iter *iter, gfp_t gfp, int end)
2142{
2143 struct radix_tree_node *node = NULL, *child;
2144 void __rcu **slot = (void __rcu **)&root->rnode;
2145 unsigned long maxindex, start = iter->next_index;
2146 unsigned long max = end > 0 ? end - 1 : INT_MAX;
2147 unsigned int shift, offset = 0;
2148
2149 grow:
2150 shift = radix_tree_load_root(root, &child, &maxindex);
2151 if (!radix_tree_tagged(root, IDR_FREE))
2152 start = max(start, maxindex + 1);
2153 if (start > max)
2154 return ERR_PTR(-ENOSPC);
2155
2156 if (start > maxindex) {
2157 int error = radix_tree_extend(root, gfp, start, shift);
2158 if (error < 0)
2159 return ERR_PTR(error);
2160 shift = error;
2161 child = rcu_dereference_raw(root->rnode);
2162 }
2163
2164 while (shift) {
2165 shift -= RADIX_TREE_MAP_SHIFT;
2166 if (child == NULL) {
2167 /* Have to add a child node. */
2168 child = radix_tree_node_alloc(gfp, node, root, shift,
2169 offset, 0, 0);
2170 if (!child)
2171 return ERR_PTR(-ENOMEM);
2172 all_tag_set(child, IDR_FREE);
2173 rcu_assign_pointer(*slot, node_to_entry(child));
2174 if (node)
2175 node->count++;
2176 } else if (!radix_tree_is_internal_node(child))
2177 break;
2178
2179 node = entry_to_node(child);
2180 offset = radix_tree_descend(node, &child, start);
2181 if (!tag_get(node, IDR_FREE, offset)) {
2182 offset = radix_tree_find_next_bit(node, IDR_FREE,
2183 offset + 1);
2184 start = next_index(start, node, offset);
2185 if (start > max)
2186 return ERR_PTR(-ENOSPC);
2187 while (offset == RADIX_TREE_MAP_SIZE) {
2188 offset = node->offset + 1;
2189 node = node->parent;
2190 if (!node)
2191 goto grow;
2192 shift = node->shift;
2193 }
2194 child = rcu_dereference_raw(node->slots[offset]);
2195 }
2196 slot = &node->slots[offset];
2197 }
2198
2199 iter->index = start;
2200 if (node)
2201 iter->next_index = 1 + min(max, (start | node_maxindex(node)));
2202 else
2203 iter->next_index = 1;
2204 iter->node = node;
2205 __set_iter_shift(iter, shift);
2206 set_iter_tags(iter, node, offset, IDR_FREE);
2207
2208 return slot;
2209}
2210
2211/**
2212 * idr_destroy - release all internal memory from an IDR
2213 * @idr: idr handle
2214 *
2215 * After this function is called, the IDR is empty, and may be reused or
2216 * the data structure containing it may be freed.
2217 *
2218 * A typical clean-up sequence for objects stored in an idr tree will use
2219 * idr_for_each() to free all objects, if necessary, then idr_destroy() to
2220 * free the memory used to keep track of those objects.
2221 */
2222void idr_destroy(struct idr *idr)
2223{
2224 struct radix_tree_node *node = rcu_dereference_raw(idr->idr_rt.rnode);
2225 if (radix_tree_is_internal_node(node))
2226 radix_tree_free_nodes(node);
2227 idr->idr_rt.rnode = NULL;
2228 root_tag_set(&idr->idr_rt, IDR_FREE);
2229}
2230EXPORT_SYMBOL(idr_destroy);
2231
1931static void 2232static void
1932radix_tree_node_ctor(void *arg) 2233radix_tree_node_ctor(void *arg)
1933{ 2234{
@@ -1971,10 +2272,12 @@ static int radix_tree_cpu_dead(unsigned int cpu)
1971 rtp = &per_cpu(radix_tree_preloads, cpu); 2272 rtp = &per_cpu(radix_tree_preloads, cpu);
1972 while (rtp->nr) { 2273 while (rtp->nr) {
1973 node = rtp->nodes; 2274 node = rtp->nodes;
1974 rtp->nodes = node->private_data; 2275 rtp->nodes = node->parent;
1975 kmem_cache_free(radix_tree_node_cachep, node); 2276 kmem_cache_free(radix_tree_node_cachep, node);
1976 rtp->nr--; 2277 rtp->nr--;
1977 } 2278 }
2279 kfree(per_cpu(ida_bitmap, cpu));
2280 per_cpu(ida_bitmap, cpu) = NULL;
1978 return 0; 2281 return 0;
1979} 2282}
1980 2283
generated by cgit v1.2.2 (git 2.25.0) at 2025-12-25 10:06:43 -0500