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,v 1.1.1.1 2007/10/11 23:31:50 Exp $ 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 48enum { 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 84struct 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 108static 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 */ 115static 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 139static 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", 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", 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 180static 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 */ 215struct 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"); 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", 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"); 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"); 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"); 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", 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", 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} 352EXPORT_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 */ 360void 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", 385 pool->pool_size - i); 386 387 kfree(pool->cache_bucket); 388 kfree(pool); 389} 390EXPORT_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 */ 398int 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} 410EXPORT_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 */ 421struct 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} 490EXPORT_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 */ 499int 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", 522 fmr, fmr->ref_count); 523#endif 524 525 spin_unlock_irqrestore(&pool->pool_lock, flags); 526 527 return 0; 528} 529EXPORT_SYMBOL(ib_fmr_pool_unmap); 530