git.oblomov.eu Git - linux-2.6/blob - drivers/infiniband/core/fmr_pool.c

   1 /*
   2  * Copyright (c) 2004 Topspin Communications.  All rights reserved.
   3  * Copyright (c) 2005 Sun Microsystems, Inc. All rights reserved.
   4  *
   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:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  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.
  23  *
  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
  31  * SOFTWARE.
  32  *
  33  * $Id: fmr_pool.c 2730 2005-06-28 16:43:03Z sean.hefty $
  34  */
  35
  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>
  41
  42 #include <rdma/ib_fmr_pool.h>
  43
  44 #include "core_priv.h"
  45
  46 #define PFX "fmr_pool: "
  47
  48 enum {
  49         IB_FMR_MAX_REMAPS = 32,
  50
  51         IB_FMR_HASH_BITS  = 8,
  52         IB_FMR_HASH_SIZE  = 1 << IB_FMR_HASH_BITS,
  53         IB_FMR_HASH_MASK  = IB_FMR_HASH_SIZE - 1
  54 };
  55
  56 /*
  57  * If an FMR is not in use, then the list member will point to either
  58  * its pool's free_list (if the FMR can be mapped again; that is,
  59  * remap_count < pool->max_remaps) or its pool's dirty_list (if the
  60  * FMR needs to be unmapped before being remapped).  In either of
  61  * these cases it is a bug if the ref_count is not 0.  In other words,
  62  * if ref_count is > 0, then the list member must not be linked into
  63  * either free_list or dirty_list.
  64  *
  65  * The cache_node member is used to link the FMR into a cache bucket
  66  * (if caching is enabled).  This is independent of the reference
  67  * count of the FMR.  When a valid FMR is released, its ref_count is
  68  * decremented, and if ref_count reaches 0, the FMR is placed in
  69  * either free_list or dirty_list as appropriate.  However, it is not
  70  * removed from the cache and may be "revived" if a call to
  71  * ib_fmr_register_physical() occurs before the FMR is remapped.  In
  72  * this case we just increment the ref_count and remove the FMR from
  73  * free_list/dirty_list.
  74  *
  75  * Before we remap an FMR from free_list, we remove it from the cache
  76  * (to prevent another user from obtaining a stale FMR).  When an FMR
  77  * is released, we add it to the tail of the free list, so that our
  78  * cache eviction policy is "least recently used."
  79  *
  80  * All manipulation of ref_count, list and cache_node is protected by
  81  * pool_lock to maintain consistency.
  82  */
  83
  84 struct ib_fmr_pool {
  85         spinlock_t                pool_lock;
  86
  87         int                       pool_size;
  88         int                       max_pages;
  89         int                       max_remaps;
  90         int                       dirty_watermark;
  91         int                       dirty_len;
  92         struct list_head          free_list;
  93         struct list_head          dirty_list;
  94         struct hlist_head        *cache_bucket;
  95
  96         void                     (*flush_function)(struct ib_fmr_pool *pool,
  97                                                    void *              arg);
  98         void                     *flush_arg;
  99
 100         struct task_struct       *thread;
 101
 102         atomic_t                  req_ser;
 103         atomic_t                  flush_ser;
 104
 105         wait_queue_head_t         force_wait;
 106 };
 107
 108 static inline u32 ib_fmr_hash(u64 first_page)
 109 {
 110         return jhash_2words((u32) first_page, (u32) (first_page >> 32), 0) &
 111                 (IB_FMR_HASH_SIZE - 1);
 112 }
 113
 114 /* Caller must hold pool_lock */
 115 static inline struct ib_pool_fmr *ib_fmr_cache_lookup(struct ib_fmr_pool *pool,
 116                                                       u64 *page_list,
 117                                                       int  page_list_len,
 118                                                       u64  io_virtual_address)
 119 {
 120         struct hlist_head *bucket;
 121         struct ib_pool_fmr *fmr;
 122         struct hlist_node *pos;
 123
 124         if (!pool->cache_bucket)
 125                 return NULL;
 126
 127         bucket = pool->cache_bucket + ib_fmr_hash(*page_list);
 128
 129         hlist_for_each_entry(fmr, pos, bucket, cache_node)
 130                 if (io_virtual_address == fmr->io_virtual_address &&
 131                     page_list_len      == fmr->page_list_len      &&
 132                     !memcmp(page_list, fmr->page_list,
 133                             page_list_len * sizeof *page_list))
 134                         return fmr;
 135
 136         return NULL;
 137 }
 138
 139 static void ib_fmr_batch_release(struct ib_fmr_pool *pool)
 140 {
 141         int                 ret;
 142         struct ib_pool_fmr *fmr;
 143         LIST_HEAD(unmap_list);
 144         LIST_HEAD(fmr_list);
 145
 146         spin_lock_irq(&pool->pool_lock);
 147
 148         list_for_each_entry(fmr, &pool->dirty_list, list) {
 149                 hlist_del_init(&fmr->cache_node);
 150                 fmr->remap_count = 0;
 151                 list_add_tail(&fmr->fmr->list, &fmr_list);
 152
 153 #ifdef DEBUG
 154                 if (fmr->ref_count !=0) {
 155                         printk(KERN_WARNING PFX "Unmapping FMR 0x%08x with ref count %d\n",
 156                                fmr, fmr->ref_count);
 157                 }
 158 #endif
 159         }
 160
 161         list_splice(&pool->dirty_list, &unmap_list);
 162         INIT_LIST_HEAD(&pool->dirty_list);
 163         pool->dirty_len = 0;
 164
 165         spin_unlock_irq(&pool->pool_lock);
 166
 167         if (list_empty(&unmap_list)) {
 168                 return;
 169         }
 170
 171         ret = ib_unmap_fmr(&fmr_list);
 172         if (ret)
 173                 printk(KERN_WARNING PFX "ib_unmap_fmr returned %d\n", ret);
 174
 175         spin_lock_irq(&pool->pool_lock);
 176         list_splice(&unmap_list, &pool->free_list);
 177         spin_unlock_irq(&pool->pool_lock);
 178 }
 179
 180 static int ib_fmr_cleanup_thread(void *pool_ptr)
 181 {
 182         struct ib_fmr_pool *pool = pool_ptr;
 183
 184         do {
 185                 if (pool->dirty_len >= pool->dirty_watermark ||
 186                     atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) < 0) {
 187                         ib_fmr_batch_release(pool);
 188
 189                         atomic_inc(&pool->flush_ser);
 190                         wake_up_interruptible(&pool->force_wait);
 191
 192                         if (pool->flush_function)
 193                                 pool->flush_function(pool, pool->flush_arg);
 194                 }
 195
 196                 set_current_state(TASK_INTERRUPTIBLE);
 197                 if (pool->dirty_len < pool->dirty_watermark &&
 198                     atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) >= 0 &&
 199                     !kthread_should_stop())
 200                         schedule();
 201                 __set_current_state(TASK_RUNNING);
 202         } while (!kthread_should_stop());
 203
 204         return 0;
 205 }
 206
 207 /**
 208  * ib_create_fmr_pool - Create an FMR pool
 209  * @pd:Protection domain for FMRs
 210  * @params:FMR pool parameters
 211  *
 212  * Create a pool of FMRs.  Return value is pointer to new pool or
 213  * error code if creation failed.
 214  */
 215 struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd             *pd,
 216                                        struct ib_fmr_pool_param *params)
 217 {
 218         struct ib_device   *device;
 219         struct ib_fmr_pool *pool;
 220         struct ib_device_attr *attr;
 221         int i;
 222         int ret;
 223         int max_remaps;
 224
 225         if (!params)
 226                 return ERR_PTR(-EINVAL);
 227
 228         device = pd->device;
 229         if (!device->alloc_fmr    || !device->dealloc_fmr  ||
 230             !device->map_phys_fmr || !device->unmap_fmr) {
 231                 printk(KERN_INFO PFX "Device %s does not support FMRs\n",
 232                        device->name);
 233                 return ERR_PTR(-ENOSYS);
 234         }
 235
 236         attr = kmalloc(sizeof *attr, GFP_KERNEL);
 237         if (!attr) {
 238                 printk(KERN_WARNING PFX "couldn't allocate device attr struct\n");
 239                 return ERR_PTR(-ENOMEM);
 240         }
 241
 242         ret = ib_query_device(device, attr);
 243         if (ret) {
 244                 printk(KERN_WARNING PFX "couldn't query device: %d\n", ret);
 245                 kfree(attr);
 246                 return ERR_PTR(ret);
 247         }
 248
 249         if (!attr->max_map_per_fmr)
 250                 max_remaps = IB_FMR_MAX_REMAPS;
 251         else
 252                 max_remaps = attr->max_map_per_fmr;
 253
 254         kfree(attr);
 255
 256         pool = kmalloc(sizeof *pool, GFP_KERNEL);
 257         if (!pool) {
 258                 printk(KERN_WARNING PFX "couldn't allocate pool struct\n");
 259                 return ERR_PTR(-ENOMEM);
 260         }
 261
 262         pool->cache_bucket   = NULL;
 263
 264         pool->flush_function = params->flush_function;
 265         pool->flush_arg      = params->flush_arg;
 266
 267         INIT_LIST_HEAD(&pool->free_list);
 268         INIT_LIST_HEAD(&pool->dirty_list);
 269
 270         if (params->cache) {
 271                 pool->cache_bucket =
 272                         kmalloc(IB_FMR_HASH_SIZE * sizeof *pool->cache_bucket,
 273                                 GFP_KERNEL);
 274                 if (!pool->cache_bucket) {
 275                         printk(KERN_WARNING PFX "Failed to allocate cache in pool\n");
 276                         ret = -ENOMEM;
 277                         goto out_free_pool;
 278                 }
 279
 280                 for (i = 0; i < IB_FMR_HASH_SIZE; ++i)
 281                         INIT_HLIST_HEAD(pool->cache_bucket + i);
 282         }
 283
 284         pool->pool_size       = 0;
 285         pool->max_pages       = params->max_pages_per_fmr;
 286         pool->max_remaps      = max_remaps;
 287         pool->dirty_watermark = params->dirty_watermark;
 288         pool->dirty_len       = 0;
 289         spin_lock_init(&pool->pool_lock);
 290         atomic_set(&pool->req_ser,   0);
 291         atomic_set(&pool->flush_ser, 0);
 292         init_waitqueue_head(&pool->force_wait);
 293
 294         pool->thread = kthread_create(ib_fmr_cleanup_thread,
 295                                       pool,
 296                                       "ib_fmr(%s)",
 297                                       device->name);
 298         if (IS_ERR(pool->thread)) {
 299                 printk(KERN_WARNING PFX "couldn't start cleanup thread\n");
 300                 ret = PTR_ERR(pool->thread);
 301                 goto out_free_pool;
 302         }
 303
 304         {
 305                 struct ib_pool_fmr *fmr;
 306                 struct ib_fmr_attr fmr_attr = {
 307                         .max_pages  = params->max_pages_per_fmr,
 308                         .max_maps   = pool->max_remaps,
 309                         .page_shift = params->page_shift
 310                 };
 311
 312                 for (i = 0; i < params->pool_size; ++i) {
 313                         fmr = kmalloc(sizeof *fmr + params->max_pages_per_fmr * sizeof (u64),
 314                                       GFP_KERNEL);
 315                         if (!fmr) {
 316                                 printk(KERN_WARNING PFX "failed to allocate fmr "
 317                                        "struct for FMR %d\n", i);
 318                                 goto out_fail;
 319                         }
 320
 321                         fmr->pool             = pool;
 322                         fmr->remap_count      = 0;
 323                         fmr->ref_count        = 0;
 324                         INIT_HLIST_NODE(&fmr->cache_node);
 325
 326                         fmr->fmr = ib_alloc_fmr(pd, params->access, &fmr_attr);
 327                         if (IS_ERR(fmr->fmr)) {
 328                                 printk(KERN_WARNING PFX "fmr_create failed "
 329                                        "for FMR %d\n", i);
 330                                 kfree(fmr);
 331                                 goto out_fail;
 332                         }
 333
 334                         list_add_tail(&fmr->list, &pool->free_list);
 335                         ++pool->pool_size;
 336                 }
 337         }
 338
 339         return pool;
 340
 341  out_free_pool:
 342         kfree(pool->cache_bucket);
 343         kfree(pool);
 344
 345         return ERR_PTR(ret);
 346
 347  out_fail:
 348         ib_destroy_fmr_pool(pool);
 349
 350         return ERR_PTR(-ENOMEM);
 351 }
 352 EXPORT_SYMBOL(ib_create_fmr_pool);
 353
 354 /**
 355  * ib_destroy_fmr_pool - Free FMR pool
 356  * @pool:FMR pool to free
 357  *
 358  * Destroy an FMR pool and free all associated resources.
 359  */
 360 void ib_destroy_fmr_pool(struct ib_fmr_pool *pool)
 361 {
 362         struct ib_pool_fmr *fmr;
 363         struct ib_pool_fmr *tmp;
 364         LIST_HEAD(fmr_list);
 365         int                 i;
 366
 367         kthread_stop(pool->thread);
 368         ib_fmr_batch_release(pool);
 369
 370         i = 0;
 371         list_for_each_entry_safe(fmr, tmp, &pool->free_list, list) {
 372                 if (fmr->remap_count) {
 373                         INIT_LIST_HEAD(&fmr_list);
 374                         list_add_tail(&fmr->fmr->list, &fmr_list);
 375                         ib_unmap_fmr(&fmr_list);
 376                 }
 377                 ib_dealloc_fmr(fmr->fmr);
 378                 list_del(&fmr->list);
 379                 kfree(fmr);
 380                 ++i;
 381         }
 382
 383         if (i < pool->pool_size)
 384                 printk(KERN_WARNING PFX "pool still has %d regions registered\n",
 385                        pool->pool_size - i);
 386
 387         kfree(pool->cache_bucket);
 388         kfree(pool);
 389 }
 390 EXPORT_SYMBOL(ib_destroy_fmr_pool);
 391
 392 /**
 393  * ib_flush_fmr_pool - Invalidate all unmapped FMRs
 394  * @pool:FMR pool to flush
 395  *
 396  * Ensure that all unmapped FMRs are fully invalidated.
 397  */
 398 int ib_flush_fmr_pool(struct ib_fmr_pool *pool)
 399 {
 400         int serial = atomic_inc_return(&pool->req_ser);
 401
 402         wake_up_process(pool->thread);
 403
 404         if (wait_event_interruptible(pool->force_wait,
 405                                      atomic_read(&pool->flush_ser) - serial >= 0))
 406                 return -EINTR;
 407
 408         return 0;
 409 }
 410 EXPORT_SYMBOL(ib_flush_fmr_pool);
 411
 412 /**
 413  * ib_fmr_pool_map_phys -
 414  * @pool:FMR pool to allocate FMR from
 415  * @page_list:List of pages to map
 416  * @list_len:Number of pages in @page_list
 417  * @io_virtual_address:I/O virtual address for new FMR
 418  *
 419  * Map an FMR from an FMR pool.
 420  */
 421 struct ib_pool_fmr *ib_fmr_pool_map_phys(struct ib_fmr_pool *pool_handle,
 422                                          u64                *page_list,
 423                                          int                 list_len,
 424                                          u64                 io_virtual_address)
 425 {
 426         struct ib_fmr_pool *pool = pool_handle;
 427         struct ib_pool_fmr *fmr;
 428         unsigned long       flags;
 429         int                 result;
 430
 431         if (list_len < 1 || list_len > pool->max_pages)
 432                 return ERR_PTR(-EINVAL);
 433
 434         spin_lock_irqsave(&pool->pool_lock, flags);
 435         fmr = ib_fmr_cache_lookup(pool,
 436                                   page_list,
 437                                   list_len,
 438                                   io_virtual_address);
 439         if (fmr) {
 440                 /* found in cache */
 441                 ++fmr->ref_count;
 442                 if (fmr->ref_count == 1) {
 443                         list_del(&fmr->list);
 444                 }
 445
 446                 spin_unlock_irqrestore(&pool->pool_lock, flags);
 447
 448                 return fmr;
 449         }
 450
 451         if (list_empty(&pool->free_list)) {
 452                 spin_unlock_irqrestore(&pool->pool_lock, flags);
 453                 return ERR_PTR(-EAGAIN);
 454         }
 455
 456         fmr = list_entry(pool->free_list.next, struct ib_pool_fmr, list);
 457         list_del(&fmr->list);
 458         hlist_del_init(&fmr->cache_node);
 459         spin_unlock_irqrestore(&pool->pool_lock, flags);
 460
 461         result = ib_map_phys_fmr(fmr->fmr, page_list, list_len,
 462                                  io_virtual_address);
 463
 464         if (result) {
 465                 spin_lock_irqsave(&pool->pool_lock, flags);
 466                 list_add(&fmr->list, &pool->free_list);
 467                 spin_unlock_irqrestore(&pool->pool_lock, flags);
 468
 469                 printk(KERN_WARNING PFX "fmr_map returns %d\n", result);
 470
 471                 return ERR_PTR(result);
 472         }
 473
 474         ++fmr->remap_count;
 475         fmr->ref_count = 1;
 476
 477         if (pool->cache_bucket) {
 478                 fmr->io_virtual_address = io_virtual_address;
 479                 fmr->page_list_len      = list_len;
 480                 memcpy(fmr->page_list, page_list, list_len * sizeof(*page_list));
 481
 482                 spin_lock_irqsave(&pool->pool_lock, flags);
 483                 hlist_add_head(&fmr->cache_node,
 484                                pool->cache_bucket + ib_fmr_hash(fmr->page_list[0]));
 485                 spin_unlock_irqrestore(&pool->pool_lock, flags);
 486         }
 487
 488         return fmr;
 489 }
 490 EXPORT_SYMBOL(ib_fmr_pool_map_phys);
 491
 492 /**
 493  * ib_fmr_pool_unmap - Unmap FMR
 494  * @fmr:FMR to unmap
 495  *
 496  * Unmap an FMR.  The FMR mapping may remain valid until the FMR is
 497  * reused (or until ib_flush_fmr_pool() is called).
 498  */
 499 int ib_fmr_pool_unmap(struct ib_pool_fmr *fmr)
 500 {
 501         struct ib_fmr_pool *pool;
 502         unsigned long flags;
 503
 504         pool = fmr->pool;
 505
 506         spin_lock_irqsave(&pool->pool_lock, flags);
 507
 508         --fmr->ref_count;
 509         if (!fmr->ref_count) {
 510                 if (fmr->remap_count < pool->max_remaps) {
 511                         list_add_tail(&fmr->list, &pool->free_list);
 512                 } else {
 513                         list_add_tail(&fmr->list, &pool->dirty_list);
 514                         ++pool->dirty_len;
 515                         wake_up_process(pool->thread);
 516                 }
 517         }
 518
 519 #ifdef DEBUG
 520         if (fmr->ref_count < 0)
 521                 printk(KERN_WARNING PFX "FMR %p has ref count %d < 0\n",
 522                        fmr, fmr->ref_count);
 523 #endif
 524
 525         spin_unlock_irqrestore(&pool->pool_lock, flags);
 526
 527         return 0;
 528 }
 529 EXPORT_SYMBOL(ib_fmr_pool_unmap);