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 34#include <linux/errno.h> 35#include <linux/spinlock.h> 36#include <linux/module.h> 37#include <linux/slab.h> 38#include <linux/jhash.h> 39#include <linux/kthread.h> 40 41#include <rdma/ib_fmr_pool.h> 42 43#include "core_priv.h" 44 45#define PFX "fmr_pool: " 46 47enum { 48 IB_FMR_MAX_REMAPS = 32, 49 50 IB_FMR_HASH_BITS = 8, 51 IB_FMR_HASH_SIZE = 1 << IB_FMR_HASH_BITS, 52 IB_FMR_HASH_MASK = IB_FMR_HASH_SIZE - 1 53}; 54 55/* 56 * If an FMR is not in use, then the list member will point to either 57 * its pool's free_list (if the FMR can be mapped again; that is, 58 * remap_count < pool->max_remaps) or its pool's dirty_list (if the 59 * FMR needs to be unmapped before being remapped). In either of 60 * these cases it is a bug if the ref_count is not 0. In other words, 61 * if ref_count is > 0, then the list member must not be linked into 62 * either free_list or dirty_list. 63 * 64 * The cache_node member is used to link the FMR into a cache bucket 65 * (if caching is enabled). This is independent of the reference 66 * count of the FMR. When a valid FMR is released, its ref_count is 67 * decremented, and if ref_count reaches 0, the FMR is placed in 68 * either free_list or dirty_list as appropriate. However, it is not 69 * removed from the cache and may be "revived" if a call to 70 * ib_fmr_register_physical() occurs before the FMR is remapped. In 71 * this case we just increment the ref_count and remove the FMR from 72 * free_list/dirty_list. 73 * 74 * Before we remap an FMR from free_list, we remove it from the cache 75 * (to prevent another user from obtaining a stale FMR). When an FMR 76 * is released, we add it to the tail of the free list, so that our 77 * cache eviction policy is "least recently used." 78 * 79 * All manipulation of ref_count, list and cache_node is protected by 80 * pool_lock to maintain consistency. 81 */ 82 83struct ib_fmr_pool { 84 spinlock_t pool_lock; 85 86 int pool_size; 87 int max_pages; 88 int max_remaps; 89 int dirty_watermark; 90 int dirty_len; 91 struct list_head free_list; 92 struct list_head dirty_list; 93 struct hlist_head *cache_bucket; 94 95 void (*flush_function)(struct ib_fmr_pool *pool, 96 void * arg); 97 void *flush_arg; 98 99 struct task_struct *thread; 100 101 atomic_t req_ser; 102 atomic_t flush_ser; 103 104 wait_queue_head_t force_wait; 105}; 106 107static inline u32 ib_fmr_hash(u64 first_page) 108{ 109 return jhash_2words((u32) first_page, (u32) (first_page >> 32), 0) & 110 (IB_FMR_HASH_SIZE - 1); 111} 112 113/* Caller must hold pool_lock */ 114static inline struct ib_pool_fmr *ib_fmr_cache_lookup(struct ib_fmr_pool *pool, 115 u64 *page_list, 116 int page_list_len, 117 u64 io_virtual_address) 118{ 119 struct hlist_head *bucket; 120 struct ib_pool_fmr *fmr; 121 122 if (!pool->cache_bucket) 123 return NULL; 124 125 bucket = pool->cache_bucket + ib_fmr_hash(*page_list); 126 127 hlist_for_each_entry(fmr, bucket, cache_node) 128 if (io_virtual_address == fmr->io_virtual_address && 129 page_list_len == fmr->page_list_len && 130 !memcmp(page_list, fmr->page_list, 131 page_list_len * sizeof *page_list)) 132 return fmr; 133 134 return NULL; 135} 136 137static void ib_fmr_batch_release(struct ib_fmr_pool *pool) 138{ 139 int ret; 140 struct ib_pool_fmr *fmr; 141 LIST_HEAD(unmap_list); 142 LIST_HEAD(fmr_list); 143 144 spin_lock_irq(&pool->pool_lock); 145 146 list_for_each_entry(fmr, &pool->dirty_list, list) { 147 hlist_del_init(&fmr->cache_node); 148 fmr->remap_count = 0; 149 list_add_tail(&fmr->fmr->list, &fmr_list); 150 151#ifdef DEBUG 152 if (fmr->ref_count !=0) { 153 printk(KERN_WARNING PFX "Unmapping FMR %p with ref count %d\n", 154 fmr, fmr->ref_count); 155 } 156#endif 157 } 158 159 list_splice_init(&pool->dirty_list, &unmap_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 PFX "ib_unmap_fmr returned %d\n", 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 177static int ib_fmr_cleanup_thread(void *pool_ptr) 178{ 179 struct ib_fmr_pool *pool = pool_ptr; 180 181 do { 182 if (atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) < 0) { 183 ib_fmr_batch_release(pool); 184 185 atomic_inc(&pool->flush_ser); 186 wake_up_interruptible(&pool->force_wait); 187 188 if (pool->flush_function) 189 pool->flush_function(pool, pool->flush_arg); 190 } 191 192 set_current_state(TASK_INTERRUPTIBLE); 193 if (atomic_read(&pool->flush_ser) - atomic_read(&pool->req_ser) >= 0 && 194 !kthread_should_stop()) 195 schedule(); 196 __set_current_state(TASK_RUNNING); 197 } while (!kthread_should_stop()); 198 199 return 0; 200} 201 202/** 203 * ib_create_fmr_pool - Create an FMR pool 204 * @pd:Protection domain for FMRs 205 * @params:FMR pool parameters 206 * 207 * Create a pool of FMRs. Return value is pointer to new pool or 208 * error code if creation failed. 209 */ 210struct ib_fmr_pool *ib_create_fmr_pool(struct ib_pd *pd, 211 struct ib_fmr_pool_param *params) 212{ 213 struct ib_device *device; 214 struct ib_fmr_pool *pool; 215 struct ib_device_attr *attr; 216 int i; 217 int ret; 218 int max_remaps; 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_INFO PFX "Device %s does not support FMRs\n", 227 device->name); 228 return ERR_PTR(-ENOSYS); 229 } 230 231 attr = kmalloc(sizeof *attr, GFP_KERNEL); 232 if (!attr) { 233 printk(KERN_WARNING PFX "couldn't allocate device attr struct\n"); 234 return ERR_PTR(-ENOMEM); 235 } 236 237 ret = ib_query_device(device, attr); 238 if (ret) { 239 printk(KERN_WARNING PFX "couldn't query device: %d\n", ret); 240 kfree(attr); 241 return ERR_PTR(ret); 242 } 243 244 if (!attr->max_map_per_fmr) 245 max_remaps = IB_FMR_MAX_REMAPS; 246 else 247 max_remaps = attr->max_map_per_fmr; 248 249 kfree(attr); 250 251 pool = kmalloc(sizeof *pool, GFP_KERNEL); 252 if (!pool) { 253 printk(KERN_WARNING PFX "couldn't allocate pool struct\n"); 254 return ERR_PTR(-ENOMEM); 255 } 256 257 pool->cache_bucket = NULL; 258 259 pool->flush_function = params->flush_function; 260 pool->flush_arg = params->flush_arg; 261 262 INIT_LIST_HEAD(&pool->free_list); 263 INIT_LIST_HEAD(&pool->dirty_list); 264 265 if (params->cache) { 266 pool->cache_bucket = 267 kmalloc(IB_FMR_HASH_SIZE * sizeof *pool->cache_bucket, 268 GFP_KERNEL); 269 if (!pool->cache_bucket) { 270 printk(KERN_WARNING PFX "Failed to allocate cache in pool\n"); 271 ret = -ENOMEM; 272 goto out_free_pool; 273 } 274 275 for (i = 0; i < IB_FMR_HASH_SIZE; ++i) 276 INIT_HLIST_HEAD(pool->cache_bucket + i); 277 } 278 279 pool->pool_size = 0; 280 pool->max_pages = params->max_pages_per_fmr; 281 pool->max_remaps = max_remaps; 282 pool->dirty_watermark = params->dirty_watermark; 283 pool->dirty_len = 0; 284 spin_lock_init(&pool->pool_lock); 285 atomic_set(&pool->req_ser, 0); 286 atomic_set(&pool->flush_ser, 0); 287 init_waitqueue_head(&pool->force_wait); 288 289 pool->thread = kthread_run(ib_fmr_cleanup_thread, 290 pool, 291 "ib_fmr(%s)", 292 device->name); 293 if (IS_ERR(pool->thread)) { 294 printk(KERN_WARNING PFX "couldn't start cleanup thread\n"); 295 ret = PTR_ERR(pool->thread); 296 goto out_free_pool; 297 } 298 299 { 300 struct ib_pool_fmr *fmr; 301 struct ib_fmr_attr fmr_attr = { 302 .max_pages = params->max_pages_per_fmr, 303 .max_maps = pool->max_remaps, 304 .page_shift = params->page_shift 305 }; 306 int bytes_per_fmr = sizeof *fmr; 307 308 if (pool->cache_bucket) 309 bytes_per_fmr += params->max_pages_per_fmr * sizeof (u64); 310 311 for (i = 0; i < params->pool_size; ++i) { 312 fmr = kmalloc(bytes_per_fmr, GFP_KERNEL); 313 if (!fmr) { 314 printk(KERN_WARNING PFX "failed to allocate fmr " 315 "struct for FMR %d\n", i); 316 goto out_fail; 317 } 318 319 fmr->pool = pool; 320 fmr->remap_count = 0; 321 fmr->ref_count = 0; 322 INIT_HLIST_NODE(&fmr->cache_node); 323 324 fmr->fmr = ib_alloc_fmr(pd, params->access, &fmr_attr); 325 if (IS_ERR(fmr->fmr)) { 326 printk(KERN_WARNING PFX "fmr_create failed " 327 "for FMR %d\n", i); 328 kfree(fmr); 329 goto out_fail; 330 } 331 332 list_add_tail(&fmr->list, &pool->free_list); 333 ++pool->pool_size; 334 } 335 } 336 337 return pool; 338 339 out_free_pool: 340 kfree(pool->cache_bucket); 341 kfree(pool); 342 343 return ERR_PTR(ret); 344 345 out_fail: 346 ib_destroy_fmr_pool(pool); 347 348 return ERR_PTR(-ENOMEM); 349} 350EXPORT_SYMBOL(ib_create_fmr_pool); 351 352/** 353 * ib_destroy_fmr_pool - Free FMR pool 354 * @pool:FMR pool to free 355 * 356 * Destroy an FMR pool and free all associated resources. 357 */ 358void ib_destroy_fmr_pool(struct ib_fmr_pool *pool) 359{ 360 struct ib_pool_fmr *fmr; 361 struct ib_pool_fmr *tmp; 362 LIST_HEAD(fmr_list); 363 int i; 364 365 kthread_stop(pool->thread); 366 ib_fmr_batch_release(pool); 367 368 i = 0; 369 list_for_each_entry_safe(fmr, tmp, &pool->free_list, list) { 370 if (fmr->remap_count) { 371 INIT_LIST_HEAD(&fmr_list); 372 list_add_tail(&fmr->fmr->list, &fmr_list); 373 ib_unmap_fmr(&fmr_list); 374 } 375 ib_dealloc_fmr(fmr->fmr); 376 list_del(&fmr->list); 377 kfree(fmr); 378 ++i; 379 } 380 381 if (i < pool->pool_size) 382 printk(KERN_WARNING PFX "pool still has %d regions registered\n", 383 pool->pool_size - i); 384 385 kfree(pool->cache_bucket); 386 kfree(pool); 387} 388EXPORT_SYMBOL(ib_destroy_fmr_pool); 389 390/** 391 * ib_flush_fmr_pool - Invalidate all unmapped FMRs 392 * @pool:FMR pool to flush 393 * 394 * Ensure that all unmapped FMRs are fully invalidated. 395 */ 396int ib_flush_fmr_pool(struct ib_fmr_pool *pool) 397{ 398 int serial; 399 struct ib_pool_fmr *fmr, *next; 400 401 /* 402 * The free_list holds FMRs that may have been used 403 * but have not been remapped enough times to be dirty. 404 * Put them on the dirty list now so that the cleanup 405 * thread will reap them too. 406 */ 407 spin_lock_irq(&pool->pool_lock); 408 list_for_each_entry_safe(fmr, next, &pool->free_list, list) { 409 if (fmr->remap_count > 0) 410 list_move(&fmr->list, &pool->dirty_list); 411 } 412 spin_unlock_irq(&pool->pool_lock); 413 414 serial = atomic_inc_return(&pool->req_ser); 415 wake_up_process(pool->thread); 416 417 if (wait_event_interruptible(pool->force_wait, 418 atomic_read(&pool->flush_ser) - serial >= 0)) 419 return -EINTR; 420 421 return 0; 422} 423EXPORT_SYMBOL(ib_flush_fmr_pool); 424 425/** 426 * ib_fmr_pool_map_phys - 427 * @pool:FMR pool to allocate FMR from 428 * @page_list:List of pages to map 429 * @list_len:Number of pages in @page_list 430 * @io_virtual_address:I/O virtual address for new FMR 431 * 432 * Map an FMR from an FMR pool. 433 */ 434struct ib_pool_fmr *ib_fmr_pool_map_phys(struct ib_fmr_pool *pool_handle, 435 u64 *page_list, 436 int list_len, 437 u64 io_virtual_address) 438{ 439 struct ib_fmr_pool *pool = pool_handle; 440 struct ib_pool_fmr *fmr; 441 unsigned long flags; 442 int result; 443 444 if (list_len < 1 || list_len > pool->max_pages) 445 return ERR_PTR(-EINVAL); 446 447 spin_lock_irqsave(&pool->pool_lock, flags); 448 fmr = ib_fmr_cache_lookup(pool, 449 page_list, 450 list_len, 451 io_virtual_address); 452 if (fmr) { 453 /* found in cache */ 454 ++fmr->ref_count; 455 if (fmr->ref_count == 1) { 456 list_del(&fmr->list); 457 } 458 459 spin_unlock_irqrestore(&pool->pool_lock, flags); 460 461 return fmr; 462 } 463 464 if (list_empty(&pool->free_list)) { 465 spin_unlock_irqrestore(&pool->pool_lock, flags); 466 return ERR_PTR(-EAGAIN); 467 } 468 469 fmr = list_entry(pool->free_list.next, struct ib_pool_fmr, list); 470 list_del(&fmr->list); 471 hlist_del_init(&fmr->cache_node); 472 spin_unlock_irqrestore(&pool->pool_lock, flags); 473 474 result = ib_map_phys_fmr(fmr->fmr, page_list, list_len, 475 io_virtual_address); 476 477 if (result) { 478 spin_lock_irqsave(&pool->pool_lock, flags); 479 list_add(&fmr->list, &pool->free_list); 480 spin_unlock_irqrestore(&pool->pool_lock, flags); 481 482 printk(KERN_WARNING PFX "fmr_map returns %d\n", result); 483 484 return ERR_PTR(result); 485 } 486 487 ++fmr->remap_count; 488 fmr->ref_count = 1; 489 490 if (pool->cache_bucket) { 491 fmr->io_virtual_address = io_virtual_address; 492 fmr->page_list_len = list_len; 493 memcpy(fmr->page_list, page_list, list_len * sizeof(*page_list)); 494 495 spin_lock_irqsave(&pool->pool_lock, flags); 496 hlist_add_head(&fmr->cache_node, 497 pool->cache_bucket + ib_fmr_hash(fmr->page_list[0])); 498 spin_unlock_irqrestore(&pool->pool_lock, flags); 499 } 500 501 return fmr; 502} 503EXPORT_SYMBOL(ib_fmr_pool_map_phys); 504 505/** 506 * ib_fmr_pool_unmap - Unmap FMR 507 * @fmr:FMR to unmap 508 * 509 * Unmap an FMR. The FMR mapping may remain valid until the FMR is 510 * reused (or until ib_flush_fmr_pool() is called). 511 */ 512int ib_fmr_pool_unmap(struct ib_pool_fmr *fmr) 513{ 514 struct ib_fmr_pool *pool; 515 unsigned long flags; 516 517 pool = fmr->pool; 518 519 spin_lock_irqsave(&pool->pool_lock, flags); 520 521 --fmr->ref_count; 522 if (!fmr->ref_count) { 523 if (fmr->remap_count < pool->max_remaps) { 524 list_add_tail(&fmr->list, &pool->free_list); 525 } else { 526 list_add_tail(&fmr->list, &pool->dirty_list); 527 if (++pool->dirty_len >= pool->dirty_watermark) { 528 atomic_inc(&pool->req_ser); 529 wake_up_process(pool->thread); 530 } 531 } 532 } 533 534#ifdef DEBUG 535 if (fmr->ref_count < 0) 536 printk(KERN_WARNING PFX "FMR %p has ref count %d < 0\n", 537 fmr, fmr->ref_count); 538#endif 539 540 spin_unlock_irqrestore(&pool->pool_lock, flags); 541 542 return 0; 543} 544EXPORT_SYMBOL(ib_fmr_pool_unmap); 545