1/* 2 * Copyright (c) 2006 Oracle. 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 */ 33#include <linux/kernel.h> 34#include <linux/slab.h> 35#include <linux/ratelimit.h> 36 37#include "rds.h" 38#include "iw.h" 39 40 41/* 42 * This is stored as mr->r_trans_private. 43 */ 44struct rds_iw_mr { 45 struct rds_iw_device *device; 46 struct rds_iw_mr_pool *pool; 47 struct rdma_cm_id *cm_id; 48 49 struct ib_mr *mr; 50 struct ib_fast_reg_page_list *page_list; 51 52 struct rds_iw_mapping mapping; 53 unsigned char remap_count; 54}; 55 56/* 57 * Our own little MR pool 58 */ 59struct rds_iw_mr_pool { 60 struct rds_iw_device *device; /* back ptr to the device that owns us */ 61 62 struct mutex flush_lock; /* serialize fmr invalidate */ 63 struct work_struct flush_worker; /* flush worker */ 64 65 spinlock_t list_lock; /* protect variables below */ 66 atomic_t item_count; /* total # of MRs */ 67 atomic_t dirty_count; /* # dirty of MRs */ 68 struct list_head dirty_list; /* dirty mappings */ 69 struct list_head clean_list; /* unused & unamapped MRs */ 70 atomic_t free_pinned; /* memory pinned by free MRs */ 71 unsigned long max_message_size; /* in pages */ 72 unsigned long max_items; 73 unsigned long max_items_soft; 74 unsigned long max_free_pinned; 75 int max_pages; 76}; 77 78static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all); 79static void rds_iw_mr_pool_flush_worker(struct work_struct *work); 80static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr); 81static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool, 82 struct rds_iw_mr *ibmr, 83 struct scatterlist *sg, unsigned int nents); 84static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr); 85static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool, 86 struct list_head *unmap_list, 87 struct list_head *kill_list, 88 int *unpinned); 89static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, struct rds_iw_mr *ibmr); 90 91static int rds_iw_get_device(struct rds_sock *rs, struct rds_iw_device **rds_iwdev, struct rdma_cm_id **cm_id) 92{ 93 struct rds_iw_device *iwdev; 94 struct rds_iw_cm_id *i_cm_id; 95 96 *rds_iwdev = NULL; 97 *cm_id = NULL; 98 99 list_for_each_entry(iwdev, &rds_iw_devices, list) { 100 spin_lock_irq(&iwdev->spinlock); 101 list_for_each_entry(i_cm_id, &iwdev->cm_id_list, list) { 102 struct sockaddr_in *src_addr, *dst_addr; 103 104 src_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.src_addr; 105 dst_addr = (struct sockaddr_in *)&i_cm_id->cm_id->route.addr.dst_addr; 106 107 rdsdebug("local ipaddr = %x port %d, " 108 "remote ipaddr = %x port %d" 109 "..looking for %x port %d, " 110 "remote ipaddr = %x port %d\n", 111 src_addr->sin_addr.s_addr, 112 src_addr->sin_port, 113 dst_addr->sin_addr.s_addr, 114 dst_addr->sin_port, 115 rs->rs_bound_addr, 116 rs->rs_bound_port, 117 rs->rs_conn_addr, 118 rs->rs_conn_port); 119#ifdef WORKING_TUPLE_DETECTION 120 if (src_addr->sin_addr.s_addr == rs->rs_bound_addr && 121 src_addr->sin_port == rs->rs_bound_port && 122 dst_addr->sin_addr.s_addr == rs->rs_conn_addr && 123 dst_addr->sin_port == rs->rs_conn_port) { 124#else 125 /* FIXME - needs to compare the local and remote 126 * ipaddr/port tuple, but the ipaddr is the only 127 * available information in the rds_sock (as the rest are 128 * zero'ed. It doesn't appear to be properly populated 129 * during connection setup... 130 */ 131 if (src_addr->sin_addr.s_addr == rs->rs_bound_addr) { 132#endif 133 spin_unlock_irq(&iwdev->spinlock); 134 *rds_iwdev = iwdev; 135 *cm_id = i_cm_id->cm_id; 136 return 0; 137 } 138 } 139 spin_unlock_irq(&iwdev->spinlock); 140 } 141 142 return 1; 143} 144 145static int rds_iw_add_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id) 146{ 147 struct rds_iw_cm_id *i_cm_id; 148 149 i_cm_id = kmalloc(sizeof *i_cm_id, GFP_KERNEL); 150 if (!i_cm_id) 151 return -ENOMEM; 152 153 i_cm_id->cm_id = cm_id; 154 155 spin_lock_irq(&rds_iwdev->spinlock); 156 list_add_tail(&i_cm_id->list, &rds_iwdev->cm_id_list); 157 spin_unlock_irq(&rds_iwdev->spinlock); 158 159 return 0; 160} 161 162static void rds_iw_remove_cm_id(struct rds_iw_device *rds_iwdev, 163 struct rdma_cm_id *cm_id) 164{ 165 struct rds_iw_cm_id *i_cm_id; 166 167 spin_lock_irq(&rds_iwdev->spinlock); 168 list_for_each_entry(i_cm_id, &rds_iwdev->cm_id_list, list) { 169 if (i_cm_id->cm_id == cm_id) { 170 list_del(&i_cm_id->list); 171 kfree(i_cm_id); 172 break; 173 } 174 } 175 spin_unlock_irq(&rds_iwdev->spinlock); 176} 177 178 179int rds_iw_update_cm_id(struct rds_iw_device *rds_iwdev, struct rdma_cm_id *cm_id) 180{ 181 struct sockaddr_in *src_addr, *dst_addr; 182 struct rds_iw_device *rds_iwdev_old; 183 struct rds_sock rs; 184 struct rdma_cm_id *pcm_id; 185 int rc; 186 187 src_addr = (struct sockaddr_in *)&cm_id->route.addr.src_addr; 188 dst_addr = (struct sockaddr_in *)&cm_id->route.addr.dst_addr; 189 190 rs.rs_bound_addr = src_addr->sin_addr.s_addr; 191 rs.rs_bound_port = src_addr->sin_port; 192 rs.rs_conn_addr = dst_addr->sin_addr.s_addr; 193 rs.rs_conn_port = dst_addr->sin_port; 194 195 rc = rds_iw_get_device(&rs, &rds_iwdev_old, &pcm_id); 196 if (rc) 197 rds_iw_remove_cm_id(rds_iwdev, cm_id); 198 199 return rds_iw_add_cm_id(rds_iwdev, cm_id); 200} 201 202void rds_iw_add_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn) 203{ 204 struct rds_iw_connection *ic = conn->c_transport_data; 205 206 /* conn was previously on the nodev_conns_list */ 207 spin_lock_irq(&iw_nodev_conns_lock); 208 BUG_ON(list_empty(&iw_nodev_conns)); 209 BUG_ON(list_empty(&ic->iw_node)); 210 list_del(&ic->iw_node); 211 212 spin_lock(&rds_iwdev->spinlock); 213 list_add_tail(&ic->iw_node, &rds_iwdev->conn_list); 214 spin_unlock(&rds_iwdev->spinlock); 215 spin_unlock_irq(&iw_nodev_conns_lock); 216 217 ic->rds_iwdev = rds_iwdev; 218} 219 220void rds_iw_remove_conn(struct rds_iw_device *rds_iwdev, struct rds_connection *conn) 221{ 222 struct rds_iw_connection *ic = conn->c_transport_data; 223 224 /* place conn on nodev_conns_list */ 225 spin_lock(&iw_nodev_conns_lock); 226 227 spin_lock_irq(&rds_iwdev->spinlock); 228 BUG_ON(list_empty(&ic->iw_node)); 229 list_del(&ic->iw_node); 230 spin_unlock_irq(&rds_iwdev->spinlock); 231 232 list_add_tail(&ic->iw_node, &iw_nodev_conns); 233 234 spin_unlock(&iw_nodev_conns_lock); 235 236 rds_iw_remove_cm_id(ic->rds_iwdev, ic->i_cm_id); 237 ic->rds_iwdev = NULL; 238} 239 240void __rds_iw_destroy_conns(struct list_head *list, spinlock_t *list_lock) 241{ 242 struct rds_iw_connection *ic, *_ic; 243 LIST_HEAD(tmp_list); 244 245 /* avoid calling conn_destroy with irqs off */ 246 spin_lock_irq(list_lock); 247 list_splice(list, &tmp_list); 248 INIT_LIST_HEAD(list); 249 spin_unlock_irq(list_lock); 250 251 list_for_each_entry_safe(ic, _ic, &tmp_list, iw_node) 252 rds_conn_destroy(ic->conn); 253} 254 255static void rds_iw_set_scatterlist(struct rds_iw_scatterlist *sg, 256 struct scatterlist *list, unsigned int sg_len) 257{ 258 sg->list = list; 259 sg->len = sg_len; 260 sg->dma_len = 0; 261 sg->dma_npages = 0; 262 sg->bytes = 0; 263} 264 265static u64 *rds_iw_map_scatterlist(struct rds_iw_device *rds_iwdev, 266 struct rds_iw_scatterlist *sg) 267{ 268 struct ib_device *dev = rds_iwdev->dev; 269 u64 *dma_pages = NULL; 270 int i, j, ret; 271 272 WARN_ON(sg->dma_len); 273 274 sg->dma_len = ib_dma_map_sg(dev, sg->list, sg->len, DMA_BIDIRECTIONAL); 275 if (unlikely(!sg->dma_len)) { 276 printk(KERN_WARNING "RDS/IW: dma_map_sg failed!\n"); 277 return ERR_PTR(-EBUSY); 278 } 279 280 sg->bytes = 0; 281 sg->dma_npages = 0; 282 283 ret = -EINVAL; 284 for (i = 0; i < sg->dma_len; ++i) { 285 unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]); 286 u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]); 287 u64 end_addr; 288 289 sg->bytes += dma_len; 290 291 end_addr = dma_addr + dma_len; 292 if (dma_addr & PAGE_MASK) { 293 if (i > 0) 294 goto out_unmap; 295 dma_addr &= ~PAGE_MASK; 296 } 297 if (end_addr & PAGE_MASK) { 298 if (i < sg->dma_len - 1) 299 goto out_unmap; 300 end_addr = (end_addr + PAGE_MASK) & ~PAGE_MASK; 301 } 302 303 sg->dma_npages += (end_addr - dma_addr) >> PAGE_SHIFT; 304 } 305 306 /* Now gather the dma addrs into one list */ 307 if (sg->dma_npages > fastreg_message_size) 308 goto out_unmap; 309 310 dma_pages = kmalloc(sizeof(u64) * sg->dma_npages, GFP_ATOMIC); 311 if (!dma_pages) { 312 ret = -ENOMEM; 313 goto out_unmap; 314 } 315 316 for (i = j = 0; i < sg->dma_len; ++i) { 317 unsigned int dma_len = ib_sg_dma_len(dev, &sg->list[i]); 318 u64 dma_addr = ib_sg_dma_address(dev, &sg->list[i]); 319 u64 end_addr; 320 321 end_addr = dma_addr + dma_len; 322 dma_addr &= ~PAGE_MASK; 323 for (; dma_addr < end_addr; dma_addr += PAGE_SIZE) 324 dma_pages[j++] = dma_addr; 325 BUG_ON(j > sg->dma_npages); 326 } 327 328 return dma_pages; 329 330out_unmap: 331 ib_dma_unmap_sg(rds_iwdev->dev, sg->list, sg->len, DMA_BIDIRECTIONAL); 332 sg->dma_len = 0; 333 kfree(dma_pages); 334 return ERR_PTR(ret); 335} 336 337 338struct rds_iw_mr_pool *rds_iw_create_mr_pool(struct rds_iw_device *rds_iwdev) 339{ 340 struct rds_iw_mr_pool *pool; 341 342 pool = kzalloc(sizeof(*pool), GFP_KERNEL); 343 if (!pool) { 344 printk(KERN_WARNING "RDS/IW: rds_iw_create_mr_pool alloc error\n"); 345 return ERR_PTR(-ENOMEM); 346 } 347 348 pool->device = rds_iwdev; 349 INIT_LIST_HEAD(&pool->dirty_list); 350 INIT_LIST_HEAD(&pool->clean_list); 351 mutex_init(&pool->flush_lock); 352 spin_lock_init(&pool->list_lock); 353 INIT_WORK(&pool->flush_worker, rds_iw_mr_pool_flush_worker); 354 355 pool->max_message_size = fastreg_message_size; 356 pool->max_items = fastreg_pool_size; 357 pool->max_free_pinned = pool->max_items * pool->max_message_size / 4; 358 pool->max_pages = fastreg_message_size; 359 360 /* We never allow more than max_items MRs to be allocated. 361 * When we exceed more than max_items_soft, we start freeing 362 * items more aggressively. 363 * Make sure that max_items > max_items_soft > max_items / 2 364 */ 365 pool->max_items_soft = pool->max_items * 3 / 4; 366 367 return pool; 368} 369 370void rds_iw_get_mr_info(struct rds_iw_device *rds_iwdev, struct rds_info_rdma_connection *iinfo) 371{ 372 struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool; 373 374 iinfo->rdma_mr_max = pool->max_items; 375 iinfo->rdma_mr_size = pool->max_pages; 376} 377 378void rds_iw_destroy_mr_pool(struct rds_iw_mr_pool *pool) 379{ 380 flush_workqueue(rds_wq); 381 rds_iw_flush_mr_pool(pool, 1); 382 BUG_ON(atomic_read(&pool->item_count)); 383 BUG_ON(atomic_read(&pool->free_pinned)); 384 kfree(pool); 385} 386 387static inline struct rds_iw_mr *rds_iw_reuse_fmr(struct rds_iw_mr_pool *pool) 388{ 389 struct rds_iw_mr *ibmr = NULL; 390 unsigned long flags; 391 392 spin_lock_irqsave(&pool->list_lock, flags); 393 if (!list_empty(&pool->clean_list)) { 394 ibmr = list_entry(pool->clean_list.next, struct rds_iw_mr, mapping.m_list); 395 list_del_init(&ibmr->mapping.m_list); 396 } 397 spin_unlock_irqrestore(&pool->list_lock, flags); 398 399 return ibmr; 400} 401 402static struct rds_iw_mr *rds_iw_alloc_mr(struct rds_iw_device *rds_iwdev) 403{ 404 struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool; 405 struct rds_iw_mr *ibmr = NULL; 406 int err = 0, iter = 0; 407 408 while (1) { 409 ibmr = rds_iw_reuse_fmr(pool); 410 if (ibmr) 411 return ibmr; 412 413 /* No clean MRs - now we have the choice of either 414 * allocating a fresh MR up to the limit imposed by the 415 * driver, or flush any dirty unused MRs. 416 * We try to avoid stalling in the send path if possible, 417 * so we allocate as long as we're allowed to. 418 * 419 * We're fussy with enforcing the FMR limit, though. If the driver 420 * tells us we can't use more than N fmrs, we shouldn't start 421 * arguing with it */ 422 if (atomic_inc_return(&pool->item_count) <= pool->max_items) 423 break; 424 425 atomic_dec(&pool->item_count); 426 427 if (++iter > 2) { 428 rds_iw_stats_inc(s_iw_rdma_mr_pool_depleted); 429 return ERR_PTR(-EAGAIN); 430 } 431 432 /* We do have some empty MRs. Flush them out. */ 433 rds_iw_stats_inc(s_iw_rdma_mr_pool_wait); 434 rds_iw_flush_mr_pool(pool, 0); 435 } 436 437 ibmr = kzalloc(sizeof(*ibmr), GFP_KERNEL); 438 if (!ibmr) { 439 err = -ENOMEM; 440 goto out_no_cigar; 441 } 442 443 spin_lock_init(&ibmr->mapping.m_lock); 444 INIT_LIST_HEAD(&ibmr->mapping.m_list); 445 ibmr->mapping.m_mr = ibmr; 446 447 err = rds_iw_init_fastreg(pool, ibmr); 448 if (err) 449 goto out_no_cigar; 450 451 rds_iw_stats_inc(s_iw_rdma_mr_alloc); 452 return ibmr; 453 454out_no_cigar: 455 if (ibmr) { 456 rds_iw_destroy_fastreg(pool, ibmr); 457 kfree(ibmr); 458 } 459 atomic_dec(&pool->item_count); 460 return ERR_PTR(err); 461} 462 463void rds_iw_sync_mr(void *trans_private, int direction) 464{ 465 struct rds_iw_mr *ibmr = trans_private; 466 struct rds_iw_device *rds_iwdev = ibmr->device; 467 468 switch (direction) { 469 case DMA_FROM_DEVICE: 470 ib_dma_sync_sg_for_cpu(rds_iwdev->dev, ibmr->mapping.m_sg.list, 471 ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL); 472 break; 473 case DMA_TO_DEVICE: 474 ib_dma_sync_sg_for_device(rds_iwdev->dev, ibmr->mapping.m_sg.list, 475 ibmr->mapping.m_sg.dma_len, DMA_BIDIRECTIONAL); 476 break; 477 } 478} 479 480/* 481 * Flush our pool of MRs. 482 * At a minimum, all currently unused MRs are unmapped. 483 * If the number of MRs allocated exceeds the limit, we also try 484 * to free as many MRs as needed to get back to this limit. 485 */ 486static int rds_iw_flush_mr_pool(struct rds_iw_mr_pool *pool, int free_all) 487{ 488 struct rds_iw_mr *ibmr, *next; 489 LIST_HEAD(unmap_list); 490 LIST_HEAD(kill_list); 491 unsigned long flags; 492 unsigned int nfreed = 0, ncleaned = 0, unpinned = 0; 493 int ret = 0; 494 495 rds_iw_stats_inc(s_iw_rdma_mr_pool_flush); 496 497 mutex_lock(&pool->flush_lock); 498 499 spin_lock_irqsave(&pool->list_lock, flags); 500 /* Get the list of all mappings to be destroyed */ 501 list_splice_init(&pool->dirty_list, &unmap_list); 502 if (free_all) 503 list_splice_init(&pool->clean_list, &kill_list); 504 spin_unlock_irqrestore(&pool->list_lock, flags); 505 506 /* Batched invalidate of dirty MRs. 507 * For FMR based MRs, the mappings on the unmap list are 508 * actually members of an ibmr (ibmr->mapping). They either 509 * migrate to the kill_list, or have been cleaned and should be 510 * moved to the clean_list. 511 * For fastregs, they will be dynamically allocated, and 512 * will be destroyed by the unmap function. 513 */ 514 if (!list_empty(&unmap_list)) { 515 ncleaned = rds_iw_unmap_fastreg_list(pool, &unmap_list, 516 &kill_list, &unpinned); 517 /* If we've been asked to destroy all MRs, move those 518 * that were simply cleaned to the kill list */ 519 if (free_all) 520 list_splice_init(&unmap_list, &kill_list); 521 } 522 523 /* Destroy any MRs that are past their best before date */ 524 list_for_each_entry_safe(ibmr, next, &kill_list, mapping.m_list) { 525 rds_iw_stats_inc(s_iw_rdma_mr_free); 526 list_del(&ibmr->mapping.m_list); 527 rds_iw_destroy_fastreg(pool, ibmr); 528 kfree(ibmr); 529 nfreed++; 530 } 531 532 /* Anything that remains are laundered ibmrs, which we can add 533 * back to the clean list. */ 534 if (!list_empty(&unmap_list)) { 535 spin_lock_irqsave(&pool->list_lock, flags); 536 list_splice(&unmap_list, &pool->clean_list); 537 spin_unlock_irqrestore(&pool->list_lock, flags); 538 } 539 540 atomic_sub(unpinned, &pool->free_pinned); 541 atomic_sub(ncleaned, &pool->dirty_count); 542 atomic_sub(nfreed, &pool->item_count); 543 544 mutex_unlock(&pool->flush_lock); 545 return ret; 546} 547 548static void rds_iw_mr_pool_flush_worker(struct work_struct *work) 549{ 550 struct rds_iw_mr_pool *pool = container_of(work, struct rds_iw_mr_pool, flush_worker); 551 552 rds_iw_flush_mr_pool(pool, 0); 553} 554 555void rds_iw_free_mr(void *trans_private, int invalidate) 556{ 557 struct rds_iw_mr *ibmr = trans_private; 558 struct rds_iw_mr_pool *pool = ibmr->device->mr_pool; 559 560 rdsdebug("RDS/IW: free_mr nents %u\n", ibmr->mapping.m_sg.len); 561 if (!pool) 562 return; 563 564 /* Return it to the pool's free list */ 565 rds_iw_free_fastreg(pool, ibmr); 566 567 /* If we've pinned too many pages, request a flush */ 568 if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned || 569 atomic_read(&pool->dirty_count) >= pool->max_items / 10) 570 queue_work(rds_wq, &pool->flush_worker); 571 572 if (invalidate) { 573 if (likely(!in_interrupt())) { 574 rds_iw_flush_mr_pool(pool, 0); 575 } else { 576 /* We get here if the user created a MR marked 577 * as use_once and invalidate at the same time. */ 578 queue_work(rds_wq, &pool->flush_worker); 579 } 580 } 581} 582 583void rds_iw_flush_mrs(void) 584{ 585 struct rds_iw_device *rds_iwdev; 586 587 list_for_each_entry(rds_iwdev, &rds_iw_devices, list) { 588 struct rds_iw_mr_pool *pool = rds_iwdev->mr_pool; 589 590 if (pool) 591 rds_iw_flush_mr_pool(pool, 0); 592 } 593} 594 595void *rds_iw_get_mr(struct scatterlist *sg, unsigned long nents, 596 struct rds_sock *rs, u32 *key_ret) 597{ 598 struct rds_iw_device *rds_iwdev; 599 struct rds_iw_mr *ibmr = NULL; 600 struct rdma_cm_id *cm_id; 601 int ret; 602 603 ret = rds_iw_get_device(rs, &rds_iwdev, &cm_id); 604 if (ret || !cm_id) { 605 ret = -ENODEV; 606 goto out; 607 } 608 609 if (!rds_iwdev->mr_pool) { 610 ret = -ENODEV; 611 goto out; 612 } 613 614 ibmr = rds_iw_alloc_mr(rds_iwdev); 615 if (IS_ERR(ibmr)) 616 return ibmr; 617 618 ibmr->cm_id = cm_id; 619 ibmr->device = rds_iwdev; 620 621 ret = rds_iw_map_fastreg(rds_iwdev->mr_pool, ibmr, sg, nents); 622 if (ret == 0) 623 *key_ret = ibmr->mr->rkey; 624 else 625 printk(KERN_WARNING "RDS/IW: failed to map mr (errno=%d)\n", ret); 626 627out: 628 if (ret) { 629 if (ibmr) 630 rds_iw_free_mr(ibmr, 0); 631 ibmr = ERR_PTR(ret); 632 } 633 return ibmr; 634} 635 636/* 637 * iWARP fastreg handling 638 * 639 * The life cycle of a fastreg registration is a bit different from 640 * FMRs. 641 * The idea behind fastreg is to have one MR, to which we bind different 642 * mappings over time. To avoid stalling on the expensive map and invalidate 643 * operations, these operations are pipelined on the same send queue on 644 * which we want to send the message containing the r_key. 645 * 646 * This creates a bit of a problem for us, as we do not have the destination 647 * IP in GET_MR, so the connection must be setup prior to the GET_MR call for 648 * RDMA to be correctly setup. If a fastreg request is present, rds_iw_xmit 649 * will try to queue a LOCAL_INV (if needed) and a FAST_REG_MR work request 650 * before queuing the SEND. When completions for these arrive, they are 651 * dispatched to the MR has a bit set showing that RDMa can be performed. 652 * 653 * There is another interesting aspect that's related to invalidation. 654 * The application can request that a mapping is invalidated in FREE_MR. 655 * The expectation there is that this invalidation step includes ALL 656 * PREVIOUSLY FREED MRs. 657 */ 658static int rds_iw_init_fastreg(struct rds_iw_mr_pool *pool, 659 struct rds_iw_mr *ibmr) 660{ 661 struct rds_iw_device *rds_iwdev = pool->device; 662 struct ib_fast_reg_page_list *page_list = NULL; 663 struct ib_mr *mr; 664 int err; 665 666 mr = ib_alloc_fast_reg_mr(rds_iwdev->pd, pool->max_message_size); 667 if (IS_ERR(mr)) { 668 err = PTR_ERR(mr); 669 670 printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_mr failed (err=%d)\n", err); 671 return err; 672 } 673 674 /* FIXME - this is overkill, but mapping->m_sg.dma_len/mapping->m_sg.dma_npages 675 * is not filled in. 676 */ 677 page_list = ib_alloc_fast_reg_page_list(rds_iwdev->dev, pool->max_message_size); 678 if (IS_ERR(page_list)) { 679 err = PTR_ERR(page_list); 680 681 printk(KERN_WARNING "RDS/IW: ib_alloc_fast_reg_page_list failed (err=%d)\n", err); 682 ib_dereg_mr(mr); 683 return err; 684 } 685 686 ibmr->page_list = page_list; 687 ibmr->mr = mr; 688 return 0; 689} 690 691static int rds_iw_rdma_build_fastreg(struct rds_iw_mapping *mapping) 692{ 693 struct rds_iw_mr *ibmr = mapping->m_mr; 694 struct ib_send_wr f_wr, *failed_wr; 695 int ret; 696 697 /* 698 * Perform a WR for the fast_reg_mr. Each individual page 699 * in the sg list is added to the fast reg page list and placed 700 * inside the fast_reg_mr WR. The key used is a rolling 8bit 701 * counter, which should guarantee uniqueness. 702 */ 703 ib_update_fast_reg_key(ibmr->mr, ibmr->remap_count++); 704 mapping->m_rkey = ibmr->mr->rkey; 705 706 memset(&f_wr, 0, sizeof(f_wr)); 707 f_wr.wr_id = RDS_IW_FAST_REG_WR_ID; 708 f_wr.opcode = IB_WR_FAST_REG_MR; 709 f_wr.wr.fast_reg.length = mapping->m_sg.bytes; 710 f_wr.wr.fast_reg.rkey = mapping->m_rkey; 711 f_wr.wr.fast_reg.page_list = ibmr->page_list; 712 f_wr.wr.fast_reg.page_list_len = mapping->m_sg.dma_len; 713 f_wr.wr.fast_reg.page_shift = PAGE_SHIFT; 714 f_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE | 715 IB_ACCESS_REMOTE_READ | 716 IB_ACCESS_REMOTE_WRITE; 717 f_wr.wr.fast_reg.iova_start = 0; 718 f_wr.send_flags = IB_SEND_SIGNALED; 719 720 failed_wr = &f_wr; 721 ret = ib_post_send(ibmr->cm_id->qp, &f_wr, &failed_wr); 722 BUG_ON(failed_wr != &f_wr); 723 if (ret) 724 printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n", 725 __func__, __LINE__, ret); 726 return ret; 727} 728 729static int rds_iw_rdma_fastreg_inv(struct rds_iw_mr *ibmr) 730{ 731 struct ib_send_wr s_wr, *failed_wr; 732 int ret = 0; 733 734 if (!ibmr->cm_id->qp || !ibmr->mr) 735 goto out; 736 737 memset(&s_wr, 0, sizeof(s_wr)); 738 s_wr.wr_id = RDS_IW_LOCAL_INV_WR_ID; 739 s_wr.opcode = IB_WR_LOCAL_INV; 740 s_wr.ex.invalidate_rkey = ibmr->mr->rkey; 741 s_wr.send_flags = IB_SEND_SIGNALED; 742 743 failed_wr = &s_wr; 744 ret = ib_post_send(ibmr->cm_id->qp, &s_wr, &failed_wr); 745 if (ret) { 746 printk_ratelimited(KERN_WARNING "RDS/IW: %s:%d ib_post_send returned %d\n", 747 __func__, __LINE__, ret); 748 goto out; 749 } 750out: 751 return ret; 752} 753 754static int rds_iw_map_fastreg(struct rds_iw_mr_pool *pool, 755 struct rds_iw_mr *ibmr, 756 struct scatterlist *sg, 757 unsigned int sg_len) 758{ 759 struct rds_iw_device *rds_iwdev = pool->device; 760 struct rds_iw_mapping *mapping = &ibmr->mapping; 761 u64 *dma_pages; 762 int i, ret = 0; 763 764 rds_iw_set_scatterlist(&mapping->m_sg, sg, sg_len); 765 766 dma_pages = rds_iw_map_scatterlist(rds_iwdev, &mapping->m_sg); 767 if (IS_ERR(dma_pages)) { 768 ret = PTR_ERR(dma_pages); 769 dma_pages = NULL; 770 goto out; 771 } 772 773 if (mapping->m_sg.dma_len > pool->max_message_size) { 774 ret = -EMSGSIZE; 775 goto out; 776 } 777 778 for (i = 0; i < mapping->m_sg.dma_npages; ++i) 779 ibmr->page_list->page_list[i] = dma_pages[i]; 780 781 ret = rds_iw_rdma_build_fastreg(mapping); 782 if (ret) 783 goto out; 784 785 rds_iw_stats_inc(s_iw_rdma_mr_used); 786 787out: 788 kfree(dma_pages); 789 790 return ret; 791} 792 793/* 794 * "Free" a fastreg MR. 795 */ 796static void rds_iw_free_fastreg(struct rds_iw_mr_pool *pool, 797 struct rds_iw_mr *ibmr) 798{ 799 unsigned long flags; 800 int ret; 801 802 if (!ibmr->mapping.m_sg.dma_len) 803 return; 804 805 ret = rds_iw_rdma_fastreg_inv(ibmr); 806 if (ret) 807 return; 808 809 /* Try to post the LOCAL_INV WR to the queue. */ 810 spin_lock_irqsave(&pool->list_lock, flags); 811 812 list_add_tail(&ibmr->mapping.m_list, &pool->dirty_list); 813 atomic_add(ibmr->mapping.m_sg.len, &pool->free_pinned); 814 atomic_inc(&pool->dirty_count); 815 816 spin_unlock_irqrestore(&pool->list_lock, flags); 817} 818 819static unsigned int rds_iw_unmap_fastreg_list(struct rds_iw_mr_pool *pool, 820 struct list_head *unmap_list, 821 struct list_head *kill_list, 822 int *unpinned) 823{ 824 struct rds_iw_mapping *mapping, *next; 825 unsigned int ncleaned = 0; 826 LIST_HEAD(laundered); 827 828 /* Batched invalidation of fastreg MRs. 829 * Why do we do it this way, even though we could pipeline unmap 830 * and remap? The reason is the application semantics - when the 831 * application requests an invalidation of MRs, it expects all 832 * previously released R_Keys to become invalid. 833 * 834 * If we implement MR reuse naively, we risk memory corruption 835 * (this has actually been observed). So the default behavior 836 * requires that a MR goes through an explicit unmap operation before 837 * we can reuse it again. 838 * 839 * We could probably improve on this a little, by allowing immediate 840 * reuse of a MR on the same socket (eg you could add small 841 * cache of unused MRs to strct rds_socket - GET_MR could grab one 842 * of these without requiring an explicit invalidate). 843 */ 844 while (!list_empty(unmap_list)) { 845 unsigned long flags; 846 847 spin_lock_irqsave(&pool->list_lock, flags); 848 list_for_each_entry_safe(mapping, next, unmap_list, m_list) { 849 *unpinned += mapping->m_sg.len; 850 list_move(&mapping->m_list, &laundered); 851 ncleaned++; 852 } 853 spin_unlock_irqrestore(&pool->list_lock, flags); 854 } 855 856 /* Move all laundered mappings back to the unmap list. 857 * We do not kill any WRs right now - it doesn't seem the 858 * fastreg API has a max_remap limit. */ 859 list_splice_init(&laundered, unmap_list); 860 861 return ncleaned; 862} 863 864static void rds_iw_destroy_fastreg(struct rds_iw_mr_pool *pool, 865 struct rds_iw_mr *ibmr) 866{ 867 if (ibmr->page_list) 868 ib_free_fast_reg_page_list(ibmr->page_list); 869 if (ibmr->mr) 870 ib_dereg_mr(ibmr->mr); 871} 872