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Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -07001/*
David Woodhousea15a5192009-07-01 18:49:06 +01002 * Copyright © 2006-2009, Intel Corporation.
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -07003 *
David Woodhousea15a5192009-07-01 18:49:06 +01004 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -07007 *
David Woodhousea15a5192009-07-01 18:49:06 +01008 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307 USA.
16 *
mark gross98bcef52008-02-23 15:23:35 -080017 * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070018 */
19
Kay, Allen M38717942008-09-09 18:37:29 +030020#include <linux/iova.h>
Sakari Ailus15bbdec2015-07-13 14:31:30 +030021#include <linux/module.h>
Robin Murphy85b45452015-01-12 17:51:14 +000022#include <linux/slab.h>
Omer Peleg9257b4a2016-04-20 11:34:11 +030023#include <linux/smp.h>
24#include <linux/bitops.h>
25
26static bool iova_rcache_insert(struct iova_domain *iovad,
27 unsigned long pfn,
28 unsigned long size);
29static unsigned long iova_rcache_get(struct iova_domain *iovad,
30 unsigned long size,
31 unsigned long limit_pfn);
32static void init_iova_rcaches(struct iova_domain *iovad);
33static void free_iova_rcaches(struct iova_domain *iovad);
Robin Murphy85b45452015-01-12 17:51:14 +000034
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070035void
Robin Murphy0fb5fe82015-01-12 17:51:16 +000036init_iova_domain(struct iova_domain *iovad, unsigned long granule,
37 unsigned long start_pfn, unsigned long pfn_32bit)
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070038{
Robin Murphy0fb5fe82015-01-12 17:51:16 +000039 /*
40 * IOVA granularity will normally be equal to the smallest
41 * supported IOMMU page size; both *must* be capable of
42 * representing individual CPU pages exactly.
43 */
44 BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
45
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070046 spin_lock_init(&iovad->iova_rbtree_lock);
47 iovad->rbroot = RB_ROOT;
48 iovad->cached32_node = NULL;
Robin Murphy0fb5fe82015-01-12 17:51:16 +000049 iovad->granule = granule;
Robin Murphy1b722502015-01-12 17:51:15 +000050 iovad->start_pfn = start_pfn;
David Millerf6611972008-02-06 01:36:23 -080051 iovad->dma_32bit_pfn = pfn_32bit;
Omer Peleg9257b4a2016-04-20 11:34:11 +030052 init_iova_rcaches(iovad);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070053}
Sakari Ailus9b417602015-07-13 14:31:29 +030054EXPORT_SYMBOL_GPL(init_iova_domain);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070055
56static struct rb_node *
57__get_cached_rbnode(struct iova_domain *iovad, unsigned long *limit_pfn)
58{
David Millerf6611972008-02-06 01:36:23 -080059 if ((*limit_pfn != iovad->dma_32bit_pfn) ||
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070060 (iovad->cached32_node == NULL))
61 return rb_last(&iovad->rbroot);
62 else {
63 struct rb_node *prev_node = rb_prev(iovad->cached32_node);
64 struct iova *curr_iova =
65 container_of(iovad->cached32_node, struct iova, node);
66 *limit_pfn = curr_iova->pfn_lo - 1;
67 return prev_node;
68 }
69}
70
71static void
72__cached_rbnode_insert_update(struct iova_domain *iovad,
73 unsigned long limit_pfn, struct iova *new)
74{
David Millerf6611972008-02-06 01:36:23 -080075 if (limit_pfn != iovad->dma_32bit_pfn)
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -070076 return;
77 iovad->cached32_node = &new->node;
78}
79
80static void
81__cached_rbnode_delete_update(struct iova_domain *iovad, struct iova *free)
82{
83 struct iova *cached_iova;
84 struct rb_node *curr;
85
86 if (!iovad->cached32_node)
87 return;
88 curr = iovad->cached32_node;
89 cached_iova = container_of(curr, struct iova, node);
90
Chris Wright1c9fc3d2011-05-28 13:15:04 -050091 if (free->pfn_lo >= cached_iova->pfn_lo) {
92 struct rb_node *node = rb_next(&free->node);
93 struct iova *iova = container_of(node, struct iova, node);
94
95 /* only cache if it's below 32bit pfn */
96 if (node && iova->pfn_lo < iovad->dma_32bit_pfn)
97 iovad->cached32_node = node;
98 else
99 iovad->cached32_node = NULL;
100 }
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700101}
102
Robin Murphy8f6429c2015-07-16 19:40:12 +0100103/*
104 * Computes the padding size required, to make the start address
105 * naturally aligned on the power-of-two order of its size
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700106 */
Robin Murphy8f6429c2015-07-16 19:40:12 +0100107static unsigned int
108iova_get_pad_size(unsigned int size, unsigned int limit_pfn)
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700109{
Robin Murphy8f6429c2015-07-16 19:40:12 +0100110 return (limit_pfn + 1 - size) & (__roundup_pow_of_two(size) - 1);
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700111}
112
mark grossddf02882008-03-04 15:22:04 -0800113static int __alloc_and_insert_iova_range(struct iova_domain *iovad,
114 unsigned long size, unsigned long limit_pfn,
115 struct iova *new, bool size_aligned)
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700116{
mark grossddf02882008-03-04 15:22:04 -0800117 struct rb_node *prev, *curr = NULL;
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700118 unsigned long flags;
119 unsigned long saved_pfn;
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700120 unsigned int pad_size = 0;
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700121
122 /* Walk the tree backwards */
123 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
124 saved_pfn = limit_pfn;
125 curr = __get_cached_rbnode(iovad, &limit_pfn);
mark grossddf02882008-03-04 15:22:04 -0800126 prev = curr;
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700127 while (curr) {
128 struct iova *curr_iova = container_of(curr, struct iova, node);
mark grossddf02882008-03-04 15:22:04 -0800129
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700130 if (limit_pfn < curr_iova->pfn_lo)
131 goto move_left;
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700132 else if (limit_pfn < curr_iova->pfn_hi)
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700133 goto adjust_limit_pfn;
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700134 else {
135 if (size_aligned)
136 pad_size = iova_get_pad_size(size, limit_pfn);
137 if ((curr_iova->pfn_hi + size + pad_size) <= limit_pfn)
138 break; /* found a free slot */
139 }
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700140adjust_limit_pfn:
141 limit_pfn = curr_iova->pfn_lo - 1;
142move_left:
mark grossddf02882008-03-04 15:22:04 -0800143 prev = curr;
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700144 curr = rb_prev(curr);
145 }
146
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700147 if (!curr) {
148 if (size_aligned)
149 pad_size = iova_get_pad_size(size, limit_pfn);
Robin Murphy1b722502015-01-12 17:51:15 +0000150 if ((iovad->start_pfn + size + pad_size) > limit_pfn) {
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700151 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
152 return -ENOMEM;
153 }
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700154 }
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700155
156 /* pfn_lo will point to size aligned address if size_aligned is set */
157 new->pfn_lo = limit_pfn - (size + pad_size) + 1;
158 new->pfn_hi = new->pfn_lo + size - 1;
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700159
mark grossddf02882008-03-04 15:22:04 -0800160 /* Insert the new_iova into domain rbtree by holding writer lock */
161 /* Add new node and rebalance tree. */
162 {
David Woodhousea15a5192009-07-01 18:49:06 +0100163 struct rb_node **entry, *parent = NULL;
164
165 /* If we have 'prev', it's a valid place to start the
166 insertion. Otherwise, start from the root. */
167 if (prev)
168 entry = &prev;
169 else
170 entry = &iovad->rbroot.rb_node;
171
mark grossddf02882008-03-04 15:22:04 -0800172 /* Figure out where to put new node */
173 while (*entry) {
174 struct iova *this = container_of(*entry,
175 struct iova, node);
176 parent = *entry;
177
178 if (new->pfn_lo < this->pfn_lo)
179 entry = &((*entry)->rb_left);
180 else if (new->pfn_lo > this->pfn_lo)
181 entry = &((*entry)->rb_right);
182 else
183 BUG(); /* this should not happen */
184 }
185
186 /* Add new node and rebalance tree. */
187 rb_link_node(&new->node, parent, entry);
188 rb_insert_color(&new->node, &iovad->rbroot);
189 }
190 __cached_rbnode_insert_update(iovad, saved_pfn, new);
191
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700192 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
mark grossddf02882008-03-04 15:22:04 -0800193
194
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700195 return 0;
196}
197
198static void
199iova_insert_rbtree(struct rb_root *root, struct iova *iova)
200{
201 struct rb_node **new = &(root->rb_node), *parent = NULL;
202 /* Figure out where to put new node */
203 while (*new) {
204 struct iova *this = container_of(*new, struct iova, node);
Robert Callicotte733cac22015-04-16 23:32:47 -0500205
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700206 parent = *new;
207
208 if (iova->pfn_lo < this->pfn_lo)
209 new = &((*new)->rb_left);
210 else if (iova->pfn_lo > this->pfn_lo)
211 new = &((*new)->rb_right);
212 else
213 BUG(); /* this should not happen */
214 }
215 /* Add new node and rebalance tree. */
216 rb_link_node(&iova->node, parent, new);
217 rb_insert_color(&iova->node, root);
218}
219
Sakari Ailusae1ff3d2015-07-13 14:31:28 +0300220static struct kmem_cache *iova_cache;
221static unsigned int iova_cache_users;
222static DEFINE_MUTEX(iova_cache_mutex);
223
224struct iova *alloc_iova_mem(void)
225{
226 return kmem_cache_alloc(iova_cache, GFP_ATOMIC);
227}
228EXPORT_SYMBOL(alloc_iova_mem);
229
230void free_iova_mem(struct iova *iova)
231{
232 kmem_cache_free(iova_cache, iova);
233}
234EXPORT_SYMBOL(free_iova_mem);
235
236int iova_cache_get(void)
237{
238 mutex_lock(&iova_cache_mutex);
239 if (!iova_cache_users) {
240 iova_cache = kmem_cache_create(
241 "iommu_iova", sizeof(struct iova), 0,
242 SLAB_HWCACHE_ALIGN, NULL);
243 if (!iova_cache) {
244 mutex_unlock(&iova_cache_mutex);
245 printk(KERN_ERR "Couldn't create iova cache\n");
246 return -ENOMEM;
247 }
248 }
249
250 iova_cache_users++;
251 mutex_unlock(&iova_cache_mutex);
252
253 return 0;
254}
Sakari Ailus9b417602015-07-13 14:31:29 +0300255EXPORT_SYMBOL_GPL(iova_cache_get);
Sakari Ailusae1ff3d2015-07-13 14:31:28 +0300256
257void iova_cache_put(void)
258{
259 mutex_lock(&iova_cache_mutex);
260 if (WARN_ON(!iova_cache_users)) {
261 mutex_unlock(&iova_cache_mutex);
262 return;
263 }
264 iova_cache_users--;
265 if (!iova_cache_users)
266 kmem_cache_destroy(iova_cache);
267 mutex_unlock(&iova_cache_mutex);
268}
Sakari Ailus9b417602015-07-13 14:31:29 +0300269EXPORT_SYMBOL_GPL(iova_cache_put);
Sakari Ailusae1ff3d2015-07-13 14:31:28 +0300270
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700271/**
272 * alloc_iova - allocates an iova
Masanari Iida07db0402012-07-22 02:21:32 +0900273 * @iovad: - iova domain in question
274 * @size: - size of page frames to allocate
275 * @limit_pfn: - max limit address
276 * @size_aligned: - set if size_aligned address range is required
Robin Murphy1b722502015-01-12 17:51:15 +0000277 * This function allocates an iova in the range iovad->start_pfn to limit_pfn,
278 * searching top-down from limit_pfn to iovad->start_pfn. If the size_aligned
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700279 * flag is set then the allocated address iova->pfn_lo will be naturally
280 * aligned on roundup_power_of_two(size).
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700281 */
282struct iova *
283alloc_iova(struct iova_domain *iovad, unsigned long size,
Keshavamurthy, Anil Sf76aec72007-10-21 16:41:58 -0700284 unsigned long limit_pfn,
285 bool size_aligned)
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700286{
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700287 struct iova *new_iova;
288 int ret;
289
290 new_iova = alloc_iova_mem();
291 if (!new_iova)
292 return NULL;
293
mark grossddf02882008-03-04 15:22:04 -0800294 ret = __alloc_and_insert_iova_range(iovad, size, limit_pfn,
295 new_iova, size_aligned);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700296
297 if (ret) {
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700298 free_iova_mem(new_iova);
299 return NULL;
300 }
301
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700302 return new_iova;
303}
Sakari Ailus9b417602015-07-13 14:31:29 +0300304EXPORT_SYMBOL_GPL(alloc_iova);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700305
Omer Peleg9257b4a2016-04-20 11:34:11 +0300306static struct iova *
307private_find_iova(struct iova_domain *iovad, unsigned long pfn)
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700308{
Omer Peleg9257b4a2016-04-20 11:34:11 +0300309 struct rb_node *node = iovad->rbroot.rb_node;
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700310
Omer Peleg9257b4a2016-04-20 11:34:11 +0300311 assert_spin_locked(&iovad->iova_rbtree_lock);
312
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700313 while (node) {
314 struct iova *iova = container_of(node, struct iova, node);
315
316 /* If pfn falls within iova's range, return iova */
317 if ((pfn >= iova->pfn_lo) && (pfn <= iova->pfn_hi)) {
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700318 return iova;
319 }
320
321 if (pfn < iova->pfn_lo)
322 node = node->rb_left;
323 else if (pfn > iova->pfn_lo)
324 node = node->rb_right;
325 }
326
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700327 return NULL;
328}
Omer Peleg9257b4a2016-04-20 11:34:11 +0300329
330static void private_free_iova(struct iova_domain *iovad, struct iova *iova)
331{
332 assert_spin_locked(&iovad->iova_rbtree_lock);
333 __cached_rbnode_delete_update(iovad, iova);
334 rb_erase(&iova->node, &iovad->rbroot);
335 free_iova_mem(iova);
336}
337
338/**
339 * find_iova - finds an iova for a given pfn
340 * @iovad: - iova domain in question.
341 * @pfn: - page frame number
342 * This function finds and returns an iova belonging to the
343 * given doamin which matches the given pfn.
344 */
345struct iova *find_iova(struct iova_domain *iovad, unsigned long pfn)
346{
347 unsigned long flags;
348 struct iova *iova;
349
350 /* Take the lock so that no other thread is manipulating the rbtree */
351 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
352 iova = private_find_iova(iovad, pfn);
353 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
354 return iova;
355}
Sakari Ailus9b417602015-07-13 14:31:29 +0300356EXPORT_SYMBOL_GPL(find_iova);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700357
358/**
359 * __free_iova - frees the given iova
360 * @iovad: iova domain in question.
361 * @iova: iova in question.
362 * Frees the given iova belonging to the giving domain
363 */
364void
365__free_iova(struct iova_domain *iovad, struct iova *iova)
366{
367 unsigned long flags;
368
369 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
Omer Peleg9257b4a2016-04-20 11:34:11 +0300370 private_free_iova(iovad, iova);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700371 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700372}
Sakari Ailus9b417602015-07-13 14:31:29 +0300373EXPORT_SYMBOL_GPL(__free_iova);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700374
375/**
376 * free_iova - finds and frees the iova for a given pfn
377 * @iovad: - iova domain in question.
378 * @pfn: - pfn that is allocated previously
379 * This functions finds an iova for a given pfn and then
380 * frees the iova from that domain.
381 */
382void
383free_iova(struct iova_domain *iovad, unsigned long pfn)
384{
385 struct iova *iova = find_iova(iovad, pfn);
Robert Callicotte733cac22015-04-16 23:32:47 -0500386
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700387 if (iova)
388 __free_iova(iovad, iova);
389
390}
Sakari Ailus9b417602015-07-13 14:31:29 +0300391EXPORT_SYMBOL_GPL(free_iova);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700392
393/**
Omer Peleg9257b4a2016-04-20 11:34:11 +0300394 * alloc_iova_fast - allocates an iova from rcache
395 * @iovad: - iova domain in question
396 * @size: - size of page frames to allocate
397 * @limit_pfn: - max limit address
398 * This function tries to satisfy an iova allocation from the rcache,
399 * and falls back to regular allocation on failure.
400*/
401unsigned long
402alloc_iova_fast(struct iova_domain *iovad, unsigned long size,
403 unsigned long limit_pfn)
404{
405 bool flushed_rcache = false;
406 unsigned long iova_pfn;
407 struct iova *new_iova;
408
409 iova_pfn = iova_rcache_get(iovad, size, limit_pfn);
410 if (iova_pfn)
411 return iova_pfn;
412
413retry:
414 new_iova = alloc_iova(iovad, size, limit_pfn, true);
415 if (!new_iova) {
416 unsigned int cpu;
417
418 if (flushed_rcache)
419 return 0;
420
421 /* Try replenishing IOVAs by flushing rcache. */
422 flushed_rcache = true;
Chris Wilson583248e2016-06-01 12:10:08 +0100423 preempt_disable();
Omer Peleg9257b4a2016-04-20 11:34:11 +0300424 for_each_online_cpu(cpu)
425 free_cpu_cached_iovas(cpu, iovad);
Chris Wilson583248e2016-06-01 12:10:08 +0100426 preempt_enable();
Omer Peleg9257b4a2016-04-20 11:34:11 +0300427 goto retry;
428 }
429
430 return new_iova->pfn_lo;
431}
432EXPORT_SYMBOL_GPL(alloc_iova_fast);
433
434/**
435 * free_iova_fast - free iova pfn range into rcache
436 * @iovad: - iova domain in question.
437 * @pfn: - pfn that is allocated previously
438 * @size: - # of pages in range
439 * This functions frees an iova range by trying to put it into the rcache,
440 * falling back to regular iova deallocation via free_iova() if this fails.
441 */
442void
443free_iova_fast(struct iova_domain *iovad, unsigned long pfn, unsigned long size)
444{
445 if (iova_rcache_insert(iovad, pfn, size))
446 return;
447
448 free_iova(iovad, pfn);
449}
450EXPORT_SYMBOL_GPL(free_iova_fast);
451
452/**
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700453 * put_iova_domain - destroys the iova doamin
454 * @iovad: - iova domain in question.
455 * All the iova's in that domain are destroyed.
456 */
457void put_iova_domain(struct iova_domain *iovad)
458{
459 struct rb_node *node;
460 unsigned long flags;
461
Omer Peleg9257b4a2016-04-20 11:34:11 +0300462 free_iova_rcaches(iovad);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700463 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
464 node = rb_first(&iovad->rbroot);
465 while (node) {
466 struct iova *iova = container_of(node, struct iova, node);
Robert Callicotte733cac22015-04-16 23:32:47 -0500467
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700468 rb_erase(node, &iovad->rbroot);
469 free_iova_mem(iova);
470 node = rb_first(&iovad->rbroot);
471 }
472 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
473}
Sakari Ailus9b417602015-07-13 14:31:29 +0300474EXPORT_SYMBOL_GPL(put_iova_domain);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700475
476static int
477__is_range_overlap(struct rb_node *node,
478 unsigned long pfn_lo, unsigned long pfn_hi)
479{
480 struct iova *iova = container_of(node, struct iova, node);
481
482 if ((pfn_lo <= iova->pfn_hi) && (pfn_hi >= iova->pfn_lo))
483 return 1;
484 return 0;
485}
486
Jiang Liu75f05562014-02-19 14:07:37 +0800487static inline struct iova *
488alloc_and_init_iova(unsigned long pfn_lo, unsigned long pfn_hi)
489{
490 struct iova *iova;
491
492 iova = alloc_iova_mem();
493 if (iova) {
494 iova->pfn_lo = pfn_lo;
495 iova->pfn_hi = pfn_hi;
496 }
497
498 return iova;
499}
500
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700501static struct iova *
502__insert_new_range(struct iova_domain *iovad,
503 unsigned long pfn_lo, unsigned long pfn_hi)
504{
505 struct iova *iova;
506
Jiang Liu75f05562014-02-19 14:07:37 +0800507 iova = alloc_and_init_iova(pfn_lo, pfn_hi);
508 if (iova)
509 iova_insert_rbtree(&iovad->rbroot, iova);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700510
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700511 return iova;
512}
513
514static void
515__adjust_overlap_range(struct iova *iova,
516 unsigned long *pfn_lo, unsigned long *pfn_hi)
517{
518 if (*pfn_lo < iova->pfn_lo)
519 iova->pfn_lo = *pfn_lo;
520 if (*pfn_hi > iova->pfn_hi)
521 *pfn_lo = iova->pfn_hi + 1;
522}
523
524/**
525 * reserve_iova - reserves an iova in the given range
526 * @iovad: - iova domain pointer
527 * @pfn_lo: - lower page frame address
528 * @pfn_hi:- higher pfn adderss
529 * This function allocates reserves the address range from pfn_lo to pfn_hi so
530 * that this address is not dished out as part of alloc_iova.
531 */
532struct iova *
533reserve_iova(struct iova_domain *iovad,
534 unsigned long pfn_lo, unsigned long pfn_hi)
535{
536 struct rb_node *node;
537 unsigned long flags;
538 struct iova *iova;
539 unsigned int overlap = 0;
540
David Woodhouse3d39cec2009-07-08 15:23:30 +0100541 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700542 for (node = rb_first(&iovad->rbroot); node; node = rb_next(node)) {
543 if (__is_range_overlap(node, pfn_lo, pfn_hi)) {
544 iova = container_of(node, struct iova, node);
545 __adjust_overlap_range(iova, &pfn_lo, &pfn_hi);
546 if ((pfn_lo >= iova->pfn_lo) &&
547 (pfn_hi <= iova->pfn_hi))
548 goto finish;
549 overlap = 1;
550
551 } else if (overlap)
552 break;
553 }
554
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300555 /* We are here either because this is the first reserver node
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700556 * or need to insert remaining non overlap addr range
557 */
558 iova = __insert_new_range(iovad, pfn_lo, pfn_hi);
559finish:
560
David Woodhouse3d39cec2009-07-08 15:23:30 +0100561 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700562 return iova;
563}
Sakari Ailus9b417602015-07-13 14:31:29 +0300564EXPORT_SYMBOL_GPL(reserve_iova);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700565
566/**
567 * copy_reserved_iova - copies the reserved between domains
568 * @from: - source doamin from where to copy
569 * @to: - destination domin where to copy
570 * This function copies reserved iova's from one doamin to
571 * other.
572 */
573void
574copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
575{
576 unsigned long flags;
577 struct rb_node *node;
578
David Woodhouse3d39cec2009-07-08 15:23:30 +0100579 spin_lock_irqsave(&from->iova_rbtree_lock, flags);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700580 for (node = rb_first(&from->rbroot); node; node = rb_next(node)) {
581 struct iova *iova = container_of(node, struct iova, node);
582 struct iova *new_iova;
Robert Callicotte733cac22015-04-16 23:32:47 -0500583
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700584 new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
585 if (!new_iova)
586 printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",
587 iova->pfn_lo, iova->pfn_lo);
588 }
David Woodhouse3d39cec2009-07-08 15:23:30 +0100589 spin_unlock_irqrestore(&from->iova_rbtree_lock, flags);
Keshavamurthy, Anil Sf8de50e2007-10-21 16:41:48 -0700590}
Sakari Ailus9b417602015-07-13 14:31:29 +0300591EXPORT_SYMBOL_GPL(copy_reserved_iova);
Jiang Liu75f05562014-02-19 14:07:37 +0800592
593struct iova *
594split_and_remove_iova(struct iova_domain *iovad, struct iova *iova,
595 unsigned long pfn_lo, unsigned long pfn_hi)
596{
597 unsigned long flags;
598 struct iova *prev = NULL, *next = NULL;
599
600 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
601 if (iova->pfn_lo < pfn_lo) {
602 prev = alloc_and_init_iova(iova->pfn_lo, pfn_lo - 1);
603 if (prev == NULL)
604 goto error;
605 }
606 if (iova->pfn_hi > pfn_hi) {
607 next = alloc_and_init_iova(pfn_hi + 1, iova->pfn_hi);
608 if (next == NULL)
609 goto error;
610 }
611
612 __cached_rbnode_delete_update(iovad, iova);
613 rb_erase(&iova->node, &iovad->rbroot);
614
615 if (prev) {
616 iova_insert_rbtree(&iovad->rbroot, prev);
617 iova->pfn_lo = pfn_lo;
618 }
619 if (next) {
620 iova_insert_rbtree(&iovad->rbroot, next);
621 iova->pfn_hi = pfn_hi;
622 }
623 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
624
625 return iova;
626
627error:
628 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
629 if (prev)
630 free_iova_mem(prev);
631 return NULL;
632}
Sakari Ailus15bbdec2015-07-13 14:31:30 +0300633
Omer Peleg9257b4a2016-04-20 11:34:11 +0300634/*
635 * Magazine caches for IOVA ranges. For an introduction to magazines,
636 * see the USENIX 2001 paper "Magazines and Vmem: Extending the Slab
637 * Allocator to Many CPUs and Arbitrary Resources" by Bonwick and Adams.
638 * For simplicity, we use a static magazine size and don't implement the
639 * dynamic size tuning described in the paper.
640 */
641
642#define IOVA_MAG_SIZE 128
643
644struct iova_magazine {
645 unsigned long size;
646 unsigned long pfns[IOVA_MAG_SIZE];
647};
648
649struct iova_cpu_rcache {
650 spinlock_t lock;
651 struct iova_magazine *loaded;
652 struct iova_magazine *prev;
653};
654
655static struct iova_magazine *iova_magazine_alloc(gfp_t flags)
656{
657 return kzalloc(sizeof(struct iova_magazine), flags);
658}
659
660static void iova_magazine_free(struct iova_magazine *mag)
661{
662 kfree(mag);
663}
664
665static void
666iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
667{
668 unsigned long flags;
669 int i;
670
671 if (!mag)
672 return;
673
674 spin_lock_irqsave(&iovad->iova_rbtree_lock, flags);
675
676 for (i = 0 ; i < mag->size; ++i) {
677 struct iova *iova = private_find_iova(iovad, mag->pfns[i]);
678
679 BUG_ON(!iova);
680 private_free_iova(iovad, iova);
681 }
682
683 spin_unlock_irqrestore(&iovad->iova_rbtree_lock, flags);
684
685 mag->size = 0;
686}
687
688static bool iova_magazine_full(struct iova_magazine *mag)
689{
690 return (mag && mag->size == IOVA_MAG_SIZE);
691}
692
693static bool iova_magazine_empty(struct iova_magazine *mag)
694{
695 return (!mag || mag->size == 0);
696}
697
698static unsigned long iova_magazine_pop(struct iova_magazine *mag,
699 unsigned long limit_pfn)
700{
701 BUG_ON(iova_magazine_empty(mag));
702
703 if (mag->pfns[mag->size - 1] >= limit_pfn)
704 return 0;
705
706 return mag->pfns[--mag->size];
707}
708
709static void iova_magazine_push(struct iova_magazine *mag, unsigned long pfn)
710{
711 BUG_ON(iova_magazine_full(mag));
712
713 mag->pfns[mag->size++] = pfn;
714}
715
716static void init_iova_rcaches(struct iova_domain *iovad)
717{
718 struct iova_cpu_rcache *cpu_rcache;
719 struct iova_rcache *rcache;
720 unsigned int cpu;
721 int i;
722
723 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
724 rcache = &iovad->rcaches[i];
725 spin_lock_init(&rcache->lock);
726 rcache->depot_size = 0;
727 rcache->cpu_rcaches = __alloc_percpu(sizeof(*cpu_rcache), cache_line_size());
728 if (WARN_ON(!rcache->cpu_rcaches))
729 continue;
730 for_each_possible_cpu(cpu) {
731 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
732 spin_lock_init(&cpu_rcache->lock);
733 cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL);
734 cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL);
735 }
736 }
737}
738
739/*
740 * Try inserting IOVA range starting with 'iova_pfn' into 'rcache', and
741 * return true on success. Can fail if rcache is full and we can't free
742 * space, and free_iova() (our only caller) will then return the IOVA
743 * range to the rbtree instead.
744 */
745static bool __iova_rcache_insert(struct iova_domain *iovad,
746 struct iova_rcache *rcache,
747 unsigned long iova_pfn)
748{
749 struct iova_magazine *mag_to_free = NULL;
750 struct iova_cpu_rcache *cpu_rcache;
751 bool can_insert = false;
752 unsigned long flags;
753
Chris Wilson583248e2016-06-01 12:10:08 +0100754 cpu_rcache = get_cpu_ptr(rcache->cpu_rcaches);
Omer Peleg9257b4a2016-04-20 11:34:11 +0300755 spin_lock_irqsave(&cpu_rcache->lock, flags);
756
757 if (!iova_magazine_full(cpu_rcache->loaded)) {
758 can_insert = true;
759 } else if (!iova_magazine_full(cpu_rcache->prev)) {
760 swap(cpu_rcache->prev, cpu_rcache->loaded);
761 can_insert = true;
762 } else {
763 struct iova_magazine *new_mag = iova_magazine_alloc(GFP_ATOMIC);
764
765 if (new_mag) {
766 spin_lock(&rcache->lock);
767 if (rcache->depot_size < MAX_GLOBAL_MAGS) {
768 rcache->depot[rcache->depot_size++] =
769 cpu_rcache->loaded;
770 } else {
771 mag_to_free = cpu_rcache->loaded;
772 }
773 spin_unlock(&rcache->lock);
774
775 cpu_rcache->loaded = new_mag;
776 can_insert = true;
777 }
778 }
779
780 if (can_insert)
781 iova_magazine_push(cpu_rcache->loaded, iova_pfn);
782
783 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
Chris Wilson583248e2016-06-01 12:10:08 +0100784 put_cpu_ptr(rcache->cpu_rcaches);
Omer Peleg9257b4a2016-04-20 11:34:11 +0300785
786 if (mag_to_free) {
787 iova_magazine_free_pfns(mag_to_free, iovad);
788 iova_magazine_free(mag_to_free);
789 }
790
791 return can_insert;
792}
793
794static bool iova_rcache_insert(struct iova_domain *iovad, unsigned long pfn,
795 unsigned long size)
796{
797 unsigned int log_size = order_base_2(size);
798
799 if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
800 return false;
801
802 return __iova_rcache_insert(iovad, &iovad->rcaches[log_size], pfn);
803}
804
805/*
806 * Caller wants to allocate a new IOVA range from 'rcache'. If we can
807 * satisfy the request, return a matching non-NULL range and remove
808 * it from the 'rcache'.
809 */
810static unsigned long __iova_rcache_get(struct iova_rcache *rcache,
811 unsigned long limit_pfn)
812{
813 struct iova_cpu_rcache *cpu_rcache;
814 unsigned long iova_pfn = 0;
815 bool has_pfn = false;
816 unsigned long flags;
817
Chris Wilson583248e2016-06-01 12:10:08 +0100818 cpu_rcache = get_cpu_ptr(rcache->cpu_rcaches);
Omer Peleg9257b4a2016-04-20 11:34:11 +0300819 spin_lock_irqsave(&cpu_rcache->lock, flags);
820
821 if (!iova_magazine_empty(cpu_rcache->loaded)) {
822 has_pfn = true;
823 } else if (!iova_magazine_empty(cpu_rcache->prev)) {
824 swap(cpu_rcache->prev, cpu_rcache->loaded);
825 has_pfn = true;
826 } else {
827 spin_lock(&rcache->lock);
828 if (rcache->depot_size > 0) {
829 iova_magazine_free(cpu_rcache->loaded);
830 cpu_rcache->loaded = rcache->depot[--rcache->depot_size];
831 has_pfn = true;
832 }
833 spin_unlock(&rcache->lock);
834 }
835
836 if (has_pfn)
837 iova_pfn = iova_magazine_pop(cpu_rcache->loaded, limit_pfn);
838
839 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
Chris Wilson583248e2016-06-01 12:10:08 +0100840 put_cpu_ptr(rcache->cpu_rcaches);
Omer Peleg9257b4a2016-04-20 11:34:11 +0300841
842 return iova_pfn;
843}
844
845/*
846 * Try to satisfy IOVA allocation range from rcache. Fail if requested
847 * size is too big or the DMA limit we are given isn't satisfied by the
848 * top element in the magazine.
849 */
850static unsigned long iova_rcache_get(struct iova_domain *iovad,
851 unsigned long size,
852 unsigned long limit_pfn)
853{
854 unsigned int log_size = order_base_2(size);
855
856 if (log_size >= IOVA_RANGE_CACHE_MAX_SIZE)
857 return 0;
858
859 return __iova_rcache_get(&iovad->rcaches[log_size], limit_pfn);
860}
861
862/*
863 * Free a cpu's rcache.
864 */
865static void free_cpu_iova_rcache(unsigned int cpu, struct iova_domain *iovad,
866 struct iova_rcache *rcache)
867{
868 struct iova_cpu_rcache *cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
869 unsigned long flags;
870
871 spin_lock_irqsave(&cpu_rcache->lock, flags);
872
873 iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
874 iova_magazine_free(cpu_rcache->loaded);
875
876 iova_magazine_free_pfns(cpu_rcache->prev, iovad);
877 iova_magazine_free(cpu_rcache->prev);
878
879 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
880}
881
882/*
883 * free rcache data structures.
884 */
885static void free_iova_rcaches(struct iova_domain *iovad)
886{
887 struct iova_rcache *rcache;
888 unsigned long flags;
889 unsigned int cpu;
890 int i, j;
891
892 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
893 rcache = &iovad->rcaches[i];
894 for_each_possible_cpu(cpu)
895 free_cpu_iova_rcache(cpu, iovad, rcache);
896 spin_lock_irqsave(&rcache->lock, flags);
897 free_percpu(rcache->cpu_rcaches);
898 for (j = 0; j < rcache->depot_size; ++j) {
899 iova_magazine_free_pfns(rcache->depot[j], iovad);
900 iova_magazine_free(rcache->depot[j]);
901 }
902 spin_unlock_irqrestore(&rcache->lock, flags);
903 }
904}
905
906/*
907 * free all the IOVA ranges cached by a cpu (used when cpu is unplugged)
908 */
909void free_cpu_cached_iovas(unsigned int cpu, struct iova_domain *iovad)
910{
911 struct iova_cpu_rcache *cpu_rcache;
912 struct iova_rcache *rcache;
913 unsigned long flags;
914 int i;
915
916 for (i = 0; i < IOVA_RANGE_CACHE_MAX_SIZE; ++i) {
917 rcache = &iovad->rcaches[i];
918 cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu);
919 spin_lock_irqsave(&cpu_rcache->lock, flags);
920 iova_magazine_free_pfns(cpu_rcache->loaded, iovad);
921 iova_magazine_free_pfns(cpu_rcache->prev, iovad);
922 spin_unlock_irqrestore(&cpu_rcache->lock, flags);
923 }
924}
925
Sakari Ailus15bbdec2015-07-13 14:31:30 +0300926MODULE_AUTHOR("Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>");
927MODULE_LICENSE("GPL");