2 * Copyright (c) 2004 Topspin Communications. All rights reserved.
3 * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
5 * This software is available to you under a choice of one of two
6 * licenses. You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
11 * Redistribution and use in source and binary forms, with or
12 * without modification, are permitted provided that the following
15 * - Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials
22 * provided with the distribution.
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 * $Id: fmr_pool.c 2730 2005-06-28 16:43:03Z sean.hefty $
36 #include <linux/errno.h>
37 #include <linux/spinlock.h>
38 #include <linux/slab.h>
39 #include <linux/jhash.h>
40 #include <linux/kthread.h>
42 #include <rdma/ib_fmr_pool.h>
44 #include "core_priv.h"
47 IB_FMR_MAX_REMAPS = 32,
50 IB_FMR_HASH_SIZE = 1 << IB_FMR_HASH_BITS,
51 IB_FMR_HASH_MASK = IB_FMR_HASH_SIZE - 1
55 * If an FMR is not in use, then the list member will point to either
56 * its pool's free_list (if the FMR can be mapped again; that is,
57 * remap_count < IB_FMR_MAX_REMAPS) or its pool's dirty_list (if the
58 * FMR needs to be unmapped before being remapped). In either of
59 * these cases it is a bug if the ref_count is not 0. In other words,
60 * if ref_count is > 0, then the list member must not be linked into
61 * either free_list or dirty_list.
63 * The cache_node member is used to link the FMR into a cache bucket
64 * (if caching is enabled). This is independent of the reference
65 * count of the FMR. When a valid FMR is released, its ref_count is
66 * decremented, and if ref_count reaches 0, the FMR is placed in
67 * either free_list or dirty_list as appropriate. However, it is not
68 * removed from the cache and may be "revived" if a call to
69 * ib_fmr_register_physical() occurs before the FMR is remapped. In
70 * this case we just increment the ref_count and remove the FMR from
71 * free_list/dirty_list.
73 * Before we remap an FMR from free_list, we remove it from the cache
74 * (to prevent another user from obtaining a stale FMR). When an FMR
75 * is released, we add it to the tail of the free list, so that our
76 * cache eviction policy is "least recently used."
78 * All manipulation of ref_count, list and cache_node is protected by
79 * pool_lock to maintain consistency.
89 struct list_head free_list;
90 struct list_head dirty_list;
91 struct hlist_head *cache_bucket;
93 void (*flush_function)(struct ib_fmr_pool *pool,
97 struct task_struct *thread;
102 wait_queue_head_t force_wait;
105 static inline u32 ib_fmr_hash(u64 first_page)
107 return jhash_2words((u32) first_page, (u32) (first_page >> 32), 0) &
108 (IB_FMR_HASH_SIZE - 1);
111 /* Caller must hold pool_lock */
112 static inline struct ib_pool_fmr *ib_fmr_cache_lookup(struct ib_fmr_pool *pool,
115 u64 io_virtual_address)
117 struct hlist_head *bucket;
118 struct ib_pool_fmr *fmr;
119 struct hlist_node *pos;
121 if (!pool->cache_bucket)
124 bucket = pool->cache_bucket + ib_fmr_hash(*page_list);
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))
136 static void ib_fmr_batch_release(struct ib_fmr_pool *pool)
139 struct ib_pool_fmr *fmr;
140 LIST_HEAD(unmap_list);
143 spin_lock_irq(&pool->pool_lock);
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);
151 if (fmr->ref_count !=0) {
152 printk(KERN_WARNING "Unmapping FMR 0x%08x with ref count %d",
153 fmr, fmr->ref_count);
158 list_splice(&pool->dirty_list, &unmap_list);
159 INIT_LIST_HEAD(&pool->dirty_list);
162 spin_unlock_irq(&pool->pool_lock);
164 if (list_empty(&unmap_list)) {
168 ret = ib_unmap_fmr(&fmr_list);
170 printk(KERN_WARNING "ib_unmap_fmr returned %d", ret);
172 spin_lock_irq(&pool->pool_lock);
173 list_splice(&unmap_list, &pool->free_list);
174 spin_unlock_irq(&pool->pool_lock);
177 static int ib_fmr_cleanup_thread(void *pool_ptr)
179 struct ib_fmr_pool *pool = pool_ptr;
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);
186 atomic_inc(&pool->flush_ser);
187 wake_up_interruptible(&pool->force_wait);
189 if (pool->flush_function)
190 pool->flush_function(pool, pool->flush_arg);
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())
198 __set_current_state(TASK_RUNNING);
199 } while (!kthread_should_stop());
205 * ib_create_fmr_pool - Create an FMR pool
206 * @pd:Protection domain for FMRs
207 * @params:FMR pool parameters
209 * Create a pool of FMRs. Return value is pointer to new pool or
210 * error code if creation failed.
212 struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd *pd,
213 struct ib_fmr_pool_param *params)
215 struct ib_device *device;
216 struct ib_fmr_pool *pool;
221 return ERR_PTR(-EINVAL);
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",
228 return ERR_PTR(-ENOSYS);
231 pool = kmalloc(sizeof *pool, GFP_KERNEL);
233 printk(KERN_WARNING "couldn't allocate pool struct");
234 return ERR_PTR(-ENOMEM);
237 pool->cache_bucket = NULL;
239 pool->flush_function = params->flush_function;
240 pool->flush_arg = params->flush_arg;
242 INIT_LIST_HEAD(&pool->free_list);
243 INIT_LIST_HEAD(&pool->dirty_list);
247 kmalloc(IB_FMR_HASH_SIZE * sizeof *pool->cache_bucket,
249 if (!pool->cache_bucket) {
250 printk(KERN_WARNING "Failed to allocate cache in pool");
255 for (i = 0; i < IB_FMR_HASH_SIZE; ++i)
256 INIT_HLIST_HEAD(pool->cache_bucket + i);
260 pool->max_pages = params->max_pages_per_fmr;
261 pool->dirty_watermark = params->dirty_watermark;
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);
268 pool->thread = kthread_create(ib_fmr_cleanup_thread,
272 if (IS_ERR(pool->thread)) {
273 printk(KERN_WARNING "couldn't start cleanup thread");
274 ret = PTR_ERR(pool->thread);
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
286 for (i = 0; i < params->pool_size; ++i) {
287 fmr = kmalloc(sizeof *fmr + params->max_pages_per_fmr * sizeof (u64),
290 printk(KERN_WARNING "failed to allocate fmr struct "
296 fmr->remap_count = 0;
298 INIT_HLIST_NODE(&fmr->cache_node);
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);
307 list_add_tail(&fmr->list, &pool->free_list);
315 kfree(pool->cache_bucket);
321 ib_destroy_fmr_pool(pool);
323 return ERR_PTR(-ENOMEM);
325 EXPORT_SYMBOL(ib_create_fmr_pool);
328 * ib_destroy_fmr_pool - Free FMR pool
329 * @pool:FMR pool to free
331 * Destroy an FMR pool and free all associated resources.
333 void ib_destroy_fmr_pool(struct ib_fmr_pool *pool)
335 struct ib_pool_fmr *fmr;
336 struct ib_pool_fmr *tmp;
340 kthread_stop(pool->thread);
341 ib_fmr_batch_release(pool);
344 list_for_each_entry_safe(fmr, tmp, &pool->free_list, list) {
345 if (fmr->remap_count) {
346 INIT_LIST_HEAD(&fmr_list);
347 list_add_tail(&fmr->fmr->list, &fmr_list);
348 ib_unmap_fmr(&fmr_list);
350 ib_dealloc_fmr(fmr->fmr);
351 list_del(&fmr->list);
356 if (i < pool->pool_size)
357 printk(KERN_WARNING "pool still has %d regions registered",
358 pool->pool_size - i);
360 kfree(pool->cache_bucket);
363 EXPORT_SYMBOL(ib_destroy_fmr_pool);
366 * ib_flush_fmr_pool - Invalidate all unmapped FMRs
367 * @pool:FMR pool to flush
369 * Ensure that all unmapped FMRs are fully invalidated.
371 int ib_flush_fmr_pool(struct ib_fmr_pool *pool)
375 atomic_inc(&pool->req_ser);
377 * It's OK if someone else bumps req_ser again here -- we'll
378 * just wait a little longer.
380 serial = atomic_read(&pool->req_ser);
382 wake_up_process(pool->thread);
384 if (wait_event_interruptible(pool->force_wait,
385 atomic_read(&pool->flush_ser) -
386 atomic_read(&pool->req_ser) >= 0))
391 EXPORT_SYMBOL(ib_flush_fmr_pool);
394 * ib_fmr_pool_map_phys -
395 * @pool:FMR pool to allocate FMR from
396 * @page_list:List of pages to map
397 * @list_len:Number of pages in @page_list
398 * @io_virtual_address:I/O virtual address for new FMR
400 * Map an FMR from an FMR pool.
402 struct ib_pool_fmr *ib_fmr_pool_map_phys(struct ib_fmr_pool *pool_handle,
405 u64 *io_virtual_address)
407 struct ib_fmr_pool *pool = pool_handle;
408 struct ib_pool_fmr *fmr;
412 if (list_len < 1 || list_len > pool->max_pages)
413 return ERR_PTR(-EINVAL);
415 spin_lock_irqsave(&pool->pool_lock, flags);
416 fmr = ib_fmr_cache_lookup(pool,
419 *io_virtual_address);
423 if (fmr->ref_count == 1) {
424 list_del(&fmr->list);
427 spin_unlock_irqrestore(&pool->pool_lock, flags);
432 if (list_empty(&pool->free_list)) {
433 spin_unlock_irqrestore(&pool->pool_lock, flags);
434 return ERR_PTR(-EAGAIN);
437 fmr = list_entry(pool->free_list.next, struct ib_pool_fmr, list);
438 list_del(&fmr->list);
439 hlist_del_init(&fmr->cache_node);
440 spin_unlock_irqrestore(&pool->pool_lock, flags);
442 result = ib_map_phys_fmr(fmr->fmr, page_list, list_len,
443 *io_virtual_address);
446 spin_lock_irqsave(&pool->pool_lock, flags);
447 list_add(&fmr->list, &pool->free_list);
448 spin_unlock_irqrestore(&pool->pool_lock, flags);
450 printk(KERN_WARNING "fmr_map returns %d\n",
453 return ERR_PTR(result);
459 if (pool->cache_bucket) {
460 fmr->io_virtual_address = *io_virtual_address;
461 fmr->page_list_len = list_len;
462 memcpy(fmr->page_list, page_list, list_len * sizeof(*page_list));
464 spin_lock_irqsave(&pool->pool_lock, flags);
465 hlist_add_head(&fmr->cache_node,
466 pool->cache_bucket + ib_fmr_hash(fmr->page_list[0]));
467 spin_unlock_irqrestore(&pool->pool_lock, flags);
472 EXPORT_SYMBOL(ib_fmr_pool_map_phys);
475 * ib_fmr_pool_unmap - Unmap FMR
478 * Unmap an FMR. The FMR mapping may remain valid until the FMR is
479 * reused (or until ib_flush_fmr_pool() is called).
481 int ib_fmr_pool_unmap(struct ib_pool_fmr *fmr)
483 struct ib_fmr_pool *pool;
488 spin_lock_irqsave(&pool->pool_lock, flags);
491 if (!fmr->ref_count) {
492 if (fmr->remap_count < IB_FMR_MAX_REMAPS) {
493 list_add_tail(&fmr->list, &pool->free_list);
495 list_add_tail(&fmr->list, &pool->dirty_list);
497 wake_up_process(pool->thread);
502 if (fmr->ref_count < 0)
503 printk(KERN_WARNING "FMR %p has ref count %d < 0",
504 fmr, fmr->ref_count);
507 spin_unlock_irqrestore(&pool->pool_lock, flags);
511 EXPORT_SYMBOL(ib_fmr_pool_unmap);