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1 | /* |
2 | * Copyright (c) 2004 Topspin Communications. All rights reserved. | |
3 | * | |
4 | * This software is available to you under a choice of one of two | |
5 | * licenses. You may choose to be licensed under the terms of the GNU | |
6 | * General Public License (GPL) Version 2, available from the file | |
7 | * COPYING in the main directory of this source tree, or the | |
8 | * OpenIB.org BSD license below: | |
9 | * | |
10 | * Redistribution and use in source and binary forms, with or | |
11 | * without modification, are permitted provided that the following | |
12 | * conditions are met: | |
13 | * | |
14 | * - Redistributions of source code must retain the above | |
15 | * copyright notice, this list of conditions and the following | |
16 | * disclaimer. | |
17 | * | |
18 | * - Redistributions in binary form must reproduce the above | |
19 | * copyright notice, this list of conditions and the following | |
20 | * disclaimer in the documentation and/or other materials | |
21 | * provided with the distribution. | |
22 | * | |
23 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, | |
24 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF | |
25 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND | |
26 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS | |
27 | * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN | |
28 | * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN | |
29 | * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
30 | * SOFTWARE. | |
31 | * | |
32 | * $Id: fmr_pool.c 1349 2004-12-16 21:09:43Z roland $ | |
33 | */ | |
34 | ||
35 | #include <linux/errno.h> | |
36 | #include <linux/spinlock.h> | |
37 | #include <linux/slab.h> | |
38 | #include <linux/jhash.h> | |
39 | #include <linux/kthread.h> | |
40 | ||
41 | #include <ib_fmr_pool.h> | |
42 | ||
43 | #include "core_priv.h" | |
44 | ||
45 | enum { | |
46 | IB_FMR_MAX_REMAPS = 32, | |
47 | ||
48 | IB_FMR_HASH_BITS = 8, | |
49 | IB_FMR_HASH_SIZE = 1 << IB_FMR_HASH_BITS, | |
50 | IB_FMR_HASH_MASK = IB_FMR_HASH_SIZE - 1 | |
51 | }; | |
52 | ||
53 | /* | |
54 | * If an FMR is not in use, then the list member will point to either | |
55 | * its pool's free_list (if the FMR can be mapped again; that is, | |
56 | * remap_count < IB_FMR_MAX_REMAPS) or its pool's dirty_list (if the | |
57 | * FMR needs to be unmapped before being remapped). In either of | |
58 | * these cases it is a bug if the ref_count is not 0. In other words, | |
59 | * if ref_count is > 0, then the list member must not be linked into | |
60 | * either free_list or dirty_list. | |
61 | * | |
62 | * The cache_node member is used to link the FMR into a cache bucket | |
63 | * (if caching is enabled). This is independent of the reference | |
64 | * count of the FMR. When a valid FMR is released, its ref_count is | |
65 | * decremented, and if ref_count reaches 0, the FMR is placed in | |
66 | * either free_list or dirty_list as appropriate. However, it is not | |
67 | * removed from the cache and may be "revived" if a call to | |
68 | * ib_fmr_register_physical() occurs before the FMR is remapped. In | |
69 | * this case we just increment the ref_count and remove the FMR from | |
70 | * free_list/dirty_list. | |
71 | * | |
72 | * Before we remap an FMR from free_list, we remove it from the cache | |
73 | * (to prevent another user from obtaining a stale FMR). When an FMR | |
74 | * is released, we add it to the tail of the free list, so that our | |
75 | * cache eviction policy is "least recently used." | |
76 | * | |
77 | * All manipulation of ref_count, list and cache_node is protected by | |
78 | * pool_lock to maintain consistency. | |
79 | */ | |
80 | ||
81 | struct ib_fmr_pool { | |
82 | spinlock_t pool_lock; | |
83 | ||
84 | int pool_size; | |
85 | int max_pages; | |
86 | int dirty_watermark; | |
87 | int dirty_len; | |
88 | struct list_head free_list; | |
89 | struct list_head dirty_list; | |
90 | struct hlist_head *cache_bucket; | |
91 | ||
92 | void (*flush_function)(struct ib_fmr_pool *pool, | |
93 | void * arg); | |
94 | void *flush_arg; | |
95 | ||
96 | struct task_struct *thread; | |
97 | ||
98 | atomic_t req_ser; | |
99 | atomic_t flush_ser; | |
100 | ||
101 | wait_queue_head_t force_wait; | |
102 | }; | |
103 | ||
104 | static inline u32 ib_fmr_hash(u64 first_page) | |
105 | { | |
106 | return jhash_2words((u32) first_page, | |
107 | (u32) (first_page >> 32), | |
108 | 0); | |
109 | } | |
110 | ||
111 | /* Caller must hold pool_lock */ | |
112 | static inline struct ib_pool_fmr *ib_fmr_cache_lookup(struct ib_fmr_pool *pool, | |
113 | u64 *page_list, | |
114 | int page_list_len, | |
115 | u64 io_virtual_address) | |
116 | { | |
117 | struct hlist_head *bucket; | |
118 | struct ib_pool_fmr *fmr; | |
119 | struct hlist_node *pos; | |
120 | ||
121 | if (!pool->cache_bucket) | |
122 | return NULL; | |
123 | ||
124 | bucket = pool->cache_bucket + ib_fmr_hash(*page_list); | |
125 | ||
126 | hlist_for_each_entry(fmr, pos, bucket, cache_node) | |
127 | if (io_virtual_address == fmr->io_virtual_address && | |
128 | page_list_len == fmr->page_list_len && | |
129 | !memcmp(page_list, fmr->page_list, | |
130 | page_list_len * sizeof *page_list)) | |
131 | return fmr; | |
132 | ||
133 | return NULL; | |
134 | } | |
135 | ||
136 | static void ib_fmr_batch_release(struct ib_fmr_pool *pool) | |
137 | { | |
138 | int ret; | |
139 | struct ib_pool_fmr *fmr; | |
140 | LIST_HEAD(unmap_list); | |
141 | LIST_HEAD(fmr_list); | |
142 | ||
143 | spin_lock_irq(&pool->pool_lock); | |
144 | ||
145 | list_for_each_entry(fmr, &pool->dirty_list, list) { | |
146 | hlist_del_init(&fmr->cache_node); | |
147 | fmr->remap_count = 0; | |
148 | list_add_tail(&fmr->fmr->list, &fmr_list); | |
149 | ||
150 | #ifdef DEBUG | |
151 | if (fmr->ref_count !=0) { | |
152 | printk(KERN_WARNING "Unmapping FMR 0x%08x with ref count %d", | |
153 | fmr, fmr->ref_count); | |
154 | } | |
155 | #endif | |
156 | } | |
157 | ||
158 | list_splice(&pool->dirty_list, &unmap_list); | |
159 | INIT_LIST_HEAD(&pool->dirty_list); | |
160 | pool->dirty_len = 0; | |
161 | ||
162 | spin_unlock_irq(&pool->pool_lock); | |
163 | ||
164 | if (list_empty(&unmap_list)) { | |
165 | return; | |
166 | } | |
167 | ||
168 | ret = ib_unmap_fmr(&fmr_list); | |
169 | if (ret) | |
170 | printk(KERN_WARNING "ib_unmap_fmr returned %d", ret); | |
171 | ||
172 | spin_lock_irq(&pool->pool_lock); | |
173 | list_splice(&unmap_list, &pool->free_list); | |
174 | spin_unlock_irq(&pool->pool_lock); | |
175 | } | |
176 | ||
177 | static int ib_fmr_cleanup_thread(void *pool_ptr) | |
178 | { | |
179 | struct ib_fmr_pool *pool = pool_ptr; | |
180 | ||
181 | do { | |
182 | if (pool->dirty_len >= pool->dirty_watermark || | |
183 | atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) < 0) { | |
184 | ib_fmr_batch_release(pool); | |
185 | ||
186 | atomic_inc(&pool->flush_ser); | |
187 | wake_up_interruptible(&pool->force_wait); | |
188 | ||
189 | if (pool->flush_function) | |
190 | pool->flush_function(pool, pool->flush_arg); | |
191 | } | |
192 | ||
193 | set_current_state(TASK_INTERRUPTIBLE); | |
194 | if (pool->dirty_len < pool->dirty_watermark && | |
195 | atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) >= 0 && | |
196 | !kthread_should_stop()) | |
197 | schedule(); | |
198 | __set_current_state(TASK_RUNNING); | |
199 | } while (!kthread_should_stop()); | |
200 | ||
201 | return 0; | |
202 | } | |
203 | ||
204 | /** | |
205 | * ib_create_fmr_pool - Create an FMR pool | |
206 | * @pd:Protection domain for FMRs | |
207 | * @params:FMR pool parameters | |
208 | * | |
209 | * Create a pool of FMRs. Return value is pointer to new pool or | |
210 | * error code if creation failed. | |
211 | */ | |
212 | struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd *pd, | |
213 | struct ib_fmr_pool_param *params) | |
214 | { | |
215 | struct ib_device *device; | |
216 | struct ib_fmr_pool *pool; | |
217 | int i; | |
218 | int ret; | |
219 | ||
220 | if (!params) | |
221 | return ERR_PTR(-EINVAL); | |
222 | ||
223 | device = pd->device; | |
224 | if (!device->alloc_fmr || !device->dealloc_fmr || | |
225 | !device->map_phys_fmr || !device->unmap_fmr) { | |
226 | printk(KERN_WARNING "Device %s does not support fast memory regions", | |
227 | device->name); | |
228 | return ERR_PTR(-ENOSYS); | |
229 | } | |
230 | ||
231 | pool = kmalloc(sizeof *pool, GFP_KERNEL); | |
232 | if (!pool) { | |
233 | printk(KERN_WARNING "couldn't allocate pool struct"); | |
234 | return ERR_PTR(-ENOMEM); | |
235 | } | |
236 | ||
237 | pool->cache_bucket = NULL; | |
238 | ||
239 | pool->flush_function = params->flush_function; | |
240 | pool->flush_arg = params->flush_arg; | |
241 | ||
242 | INIT_LIST_HEAD(&pool->free_list); | |
243 | INIT_LIST_HEAD(&pool->dirty_list); | |
244 | ||
245 | if (params->cache) { | |
246 | pool->cache_bucket = | |
247 | kmalloc(IB_FMR_HASH_SIZE * sizeof *pool->cache_bucket, | |
248 | GFP_KERNEL); | |
249 | if (!pool->cache_bucket) { | |
250 | printk(KERN_WARNING "Failed to allocate cache in pool"); | |
251 | ret = -ENOMEM; | |
252 | goto out_free_pool; | |
253 | } | |
254 | ||
255 | for (i = 0; i < IB_FMR_HASH_SIZE; ++i) | |
256 | INIT_HLIST_HEAD(pool->cache_bucket + i); | |
257 | } | |
258 | ||
259 | pool->pool_size = 0; | |
260 | pool->max_pages = params->max_pages_per_fmr; | |
261 | pool->dirty_watermark = params->dirty_watermark; | |
262 | pool->dirty_len = 0; | |
263 | spin_lock_init(&pool->pool_lock); | |
264 | atomic_set(&pool->req_ser, 0); | |
265 | atomic_set(&pool->flush_ser, 0); | |
266 | init_waitqueue_head(&pool->force_wait); | |
267 | ||
268 | pool->thread = kthread_create(ib_fmr_cleanup_thread, | |
269 | pool, | |
270 | "ib_fmr(%s)", | |
271 | device->name); | |
272 | if (IS_ERR(pool->thread)) { | |
273 | printk(KERN_WARNING "couldn't start cleanup thread"); | |
274 | ret = PTR_ERR(pool->thread); | |
275 | goto out_free_pool; | |
276 | } | |
277 | ||
278 | { | |
279 | struct ib_pool_fmr *fmr; | |
280 | struct ib_fmr_attr attr = { | |
281 | .max_pages = params->max_pages_per_fmr, | |
282 | .max_maps = IB_FMR_MAX_REMAPS, | |
283 | .page_size = PAGE_SHIFT | |
284 | }; | |
285 | ||
286 | for (i = 0; i < params->pool_size; ++i) { | |
287 | fmr = kmalloc(sizeof *fmr + params->max_pages_per_fmr * sizeof (u64), | |
288 | GFP_KERNEL); | |
289 | if (!fmr) { | |
290 | printk(KERN_WARNING "failed to allocate fmr struct " | |
291 | "for FMR %d", i); | |
292 | goto out_fail; | |
293 | } | |
294 | ||
295 | fmr->pool = pool; | |
296 | fmr->remap_count = 0; | |
297 | fmr->ref_count = 0; | |
298 | INIT_HLIST_NODE(&fmr->cache_node); | |
299 | ||
300 | fmr->fmr = ib_alloc_fmr(pd, params->access, &attr); | |
301 | if (IS_ERR(fmr->fmr)) { | |
302 | printk(KERN_WARNING "fmr_create failed for FMR %d", i); | |
303 | kfree(fmr); | |
304 | goto out_fail; | |
305 | } | |
306 | ||
307 | list_add_tail(&fmr->list, &pool->free_list); | |
308 | ++pool->pool_size; | |
309 | } | |
310 | } | |
311 | ||
312 | return pool; | |
313 | ||
314 | out_free_pool: | |
315 | kfree(pool->cache_bucket); | |
316 | kfree(pool); | |
317 | ||
318 | return ERR_PTR(ret); | |
319 | ||
320 | out_fail: | |
321 | ib_destroy_fmr_pool(pool); | |
322 | ||
323 | return ERR_PTR(-ENOMEM); | |
324 | } | |
325 | EXPORT_SYMBOL(ib_create_fmr_pool); | |
326 | ||
327 | /** | |
328 | * ib_destroy_fmr_pool - Free FMR pool | |
329 | * @pool:FMR pool to free | |
330 | * | |
331 | * Destroy an FMR pool and free all associated resources. | |
332 | */ | |
333 | int ib_destroy_fmr_pool(struct ib_fmr_pool *pool) | |
334 | { | |
335 | struct ib_pool_fmr *fmr; | |
336 | struct ib_pool_fmr *tmp; | |
337 | int i; | |
338 | ||
339 | kthread_stop(pool->thread); | |
340 | ib_fmr_batch_release(pool); | |
341 | ||
342 | i = 0; | |
343 | list_for_each_entry_safe(fmr, tmp, &pool->free_list, list) { | |
344 | ib_dealloc_fmr(fmr->fmr); | |
345 | list_del(&fmr->list); | |
346 | kfree(fmr); | |
347 | ++i; | |
348 | } | |
349 | ||
350 | if (i < pool->pool_size) | |
351 | printk(KERN_WARNING "pool still has %d regions registered", | |
352 | pool->pool_size - i); | |
353 | ||
354 | kfree(pool->cache_bucket); | |
355 | kfree(pool); | |
356 | ||
357 | return 0; | |
358 | } | |
359 | EXPORT_SYMBOL(ib_destroy_fmr_pool); | |
360 | ||
361 | /** | |
362 | * ib_flush_fmr_pool - Invalidate all unmapped FMRs | |
363 | * @pool:FMR pool to flush | |
364 | * | |
365 | * Ensure that all unmapped FMRs are fully invalidated. | |
366 | */ | |
367 | int ib_flush_fmr_pool(struct ib_fmr_pool *pool) | |
368 | { | |
369 | int serial; | |
370 | ||
371 | atomic_inc(&pool->req_ser); | |
372 | /* | |
373 | * It's OK if someone else bumps req_ser again here -- we'll | |
374 | * just wait a little longer. | |
375 | */ | |
376 | serial = atomic_read(&pool->req_ser); | |
377 | ||
378 | wake_up_process(pool->thread); | |
379 | ||
380 | if (wait_event_interruptible(pool->force_wait, | |
381 | atomic_read(&pool->flush_ser) - | |
382 | atomic_read(&pool->req_ser) >= 0)) | |
383 | return -EINTR; | |
384 | ||
385 | return 0; | |
386 | } | |
387 | EXPORT_SYMBOL(ib_flush_fmr_pool); | |
388 | ||
389 | /** | |
390 | * ib_fmr_pool_map_phys - | |
391 | * @pool:FMR pool to allocate FMR from | |
392 | * @page_list:List of pages to map | |
393 | * @list_len:Number of pages in @page_list | |
394 | * @io_virtual_address:I/O virtual address for new FMR | |
395 | * | |
396 | * Map an FMR from an FMR pool. | |
397 | */ | |
398 | struct ib_pool_fmr *ib_fmr_pool_map_phys(struct ib_fmr_pool *pool_handle, | |
399 | u64 *page_list, | |
400 | int list_len, | |
401 | u64 *io_virtual_address) | |
402 | { | |
403 | struct ib_fmr_pool *pool = pool_handle; | |
404 | struct ib_pool_fmr *fmr; | |
405 | unsigned long flags; | |
406 | int result; | |
407 | ||
408 | if (list_len < 1 || list_len > pool->max_pages) | |
409 | return ERR_PTR(-EINVAL); | |
410 | ||
411 | spin_lock_irqsave(&pool->pool_lock, flags); | |
412 | fmr = ib_fmr_cache_lookup(pool, | |
413 | page_list, | |
414 | list_len, | |
415 | *io_virtual_address); | |
416 | if (fmr) { | |
417 | /* found in cache */ | |
418 | ++fmr->ref_count; | |
419 | if (fmr->ref_count == 1) { | |
420 | list_del(&fmr->list); | |
421 | } | |
422 | ||
423 | spin_unlock_irqrestore(&pool->pool_lock, flags); | |
424 | ||
425 | return fmr; | |
426 | } | |
427 | ||
428 | if (list_empty(&pool->free_list)) { | |
429 | spin_unlock_irqrestore(&pool->pool_lock, flags); | |
430 | return ERR_PTR(-EAGAIN); | |
431 | } | |
432 | ||
433 | fmr = list_entry(pool->free_list.next, struct ib_pool_fmr, list); | |
434 | list_del(&fmr->list); | |
435 | hlist_del_init(&fmr->cache_node); | |
436 | spin_unlock_irqrestore(&pool->pool_lock, flags); | |
437 | ||
438 | result = ib_map_phys_fmr(fmr->fmr, page_list, list_len, | |
439 | *io_virtual_address); | |
440 | ||
441 | if (result) { | |
442 | spin_lock_irqsave(&pool->pool_lock, flags); | |
443 | list_add(&fmr->list, &pool->free_list); | |
444 | spin_unlock_irqrestore(&pool->pool_lock, flags); | |
445 | ||
446 | printk(KERN_WARNING "fmr_map returns %d", | |
447 | result); | |
448 | ||
449 | return ERR_PTR(result); | |
450 | } | |
451 | ||
452 | ++fmr->remap_count; | |
453 | fmr->ref_count = 1; | |
454 | ||
455 | if (pool->cache_bucket) { | |
456 | fmr->io_virtual_address = *io_virtual_address; | |
457 | fmr->page_list_len = list_len; | |
458 | memcpy(fmr->page_list, page_list, list_len * sizeof(*page_list)); | |
459 | ||
460 | spin_lock_irqsave(&pool->pool_lock, flags); | |
461 | hlist_add_head(&fmr->cache_node, | |
462 | pool->cache_bucket + ib_fmr_hash(fmr->page_list[0])); | |
463 | spin_unlock_irqrestore(&pool->pool_lock, flags); | |
464 | } | |
465 | ||
466 | return fmr; | |
467 | } | |
468 | EXPORT_SYMBOL(ib_fmr_pool_map_phys); | |
469 | ||
470 | /** | |
471 | * ib_fmr_pool_unmap - Unmap FMR | |
472 | * @fmr:FMR to unmap | |
473 | * | |
474 | * Unmap an FMR. The FMR mapping may remain valid until the FMR is | |
475 | * reused (or until ib_flush_fmr_pool() is called). | |
476 | */ | |
477 | int ib_fmr_pool_unmap(struct ib_pool_fmr *fmr) | |
478 | { | |
479 | struct ib_fmr_pool *pool; | |
480 | unsigned long flags; | |
481 | ||
482 | pool = fmr->pool; | |
483 | ||
484 | spin_lock_irqsave(&pool->pool_lock, flags); | |
485 | ||
486 | --fmr->ref_count; | |
487 | if (!fmr->ref_count) { | |
488 | if (fmr->remap_count < IB_FMR_MAX_REMAPS) { | |
489 | list_add_tail(&fmr->list, &pool->free_list); | |
490 | } else { | |
491 | list_add_tail(&fmr->list, &pool->dirty_list); | |
492 | ++pool->dirty_len; | |
493 | wake_up_process(pool->thread); | |
494 | } | |
495 | } | |
496 | ||
497 | #ifdef DEBUG | |
498 | if (fmr->ref_count < 0) | |
499 | printk(KERN_WARNING "FMR %p has ref count %d < 0", | |
500 | fmr, fmr->ref_count); | |
501 | #endif | |
502 | ||
503 | spin_unlock_irqrestore(&pool->pool_lock, flags); | |
504 | ||
505 | return 0; | |
506 | } | |
507 | EXPORT_SYMBOL(ib_fmr_pool_unmap); |