1/* 2 * Copyright (c) 2016 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 "ib_mr.h" 34 35static inline void 36rds_transition_frwr_state(struct rds_ib_mr *ibmr, 37 enum rds_ib_fr_state old_state, 38 enum rds_ib_fr_state new_state) 39{ 40 if (cmpxchg(&ibmr->u.frmr.fr_state, 41 old_state, new_state) == old_state && 42 old_state == FRMR_IS_INUSE) { 43 /* enforce order of ibmr->u.frmr.fr_state update 44 * before decrementing i_fastreg_inuse_count 45 */ 46 smp_mb__before_atomic(); 47 atomic_dec(&ibmr->ic->i_fastreg_inuse_count); 48 if (waitqueue_active(&rds_ib_ring_empty_wait)) 49 wake_up(&rds_ib_ring_empty_wait); 50 } 51} 52 53static struct rds_ib_mr *rds_ib_alloc_frmr(struct rds_ib_device *rds_ibdev, 54 int npages) 55{ 56 struct rds_ib_mr_pool *pool; 57 struct rds_ib_mr *ibmr = NULL; 58 struct rds_ib_frmr *frmr; 59 int err = 0; 60 61 if (npages <= RDS_MR_8K_MSG_SIZE) 62 pool = rds_ibdev->mr_8k_pool; 63 else 64 pool = rds_ibdev->mr_1m_pool; 65 66 ibmr = rds_ib_try_reuse_ibmr(pool); 67 if (ibmr) 68 return ibmr; 69 70 ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL, 71 rdsibdev_to_node(rds_ibdev)); 72 if (!ibmr) { 73 err = -ENOMEM; 74 goto out_no_cigar; 75 } 76 77 frmr = &ibmr->u.frmr; 78 frmr->mr = ib_alloc_mr(rds_ibdev->pd, IB_MR_TYPE_MEM_REG, 79 pool->max_pages); 80 if (IS_ERR(frmr->mr)) { 81 pr_warn("RDS/IB: %s failed to allocate MR", __func__); 82 err = PTR_ERR(frmr->mr); 83 goto out_no_cigar; 84 } 85 86 ibmr->pool = pool; 87 if (pool->pool_type == RDS_IB_MR_8K_POOL) 88 rds_ib_stats_inc(s_ib_rdma_mr_8k_alloc); 89 else 90 rds_ib_stats_inc(s_ib_rdma_mr_1m_alloc); 91 92 if (atomic_read(&pool->item_count) > pool->max_items_soft) 93 pool->max_items_soft = pool->max_items; 94 95 frmr->fr_state = FRMR_IS_FREE; 96 init_waitqueue_head(&frmr->fr_inv_done); 97 init_waitqueue_head(&frmr->fr_reg_done); 98 return ibmr; 99 100out_no_cigar: 101 kfree(ibmr); 102 atomic_dec(&pool->item_count); 103 return ERR_PTR(err); 104} 105 106static void rds_ib_free_frmr(struct rds_ib_mr *ibmr, bool drop) 107{ 108 struct rds_ib_mr_pool *pool = ibmr->pool; 109 110 if (drop) 111 llist_add(&ibmr->llnode, &pool->drop_list); 112 else 113 llist_add(&ibmr->llnode, &pool->free_list); 114 atomic_add(ibmr->sg_len, &pool->free_pinned); 115 atomic_inc(&pool->dirty_count); 116 117 /* If we've pinned too many pages, request a flush */ 118 if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned || 119 atomic_read(&pool->dirty_count) >= pool->max_items / 5) 120 queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10); 121} 122 123static int rds_ib_post_reg_frmr(struct rds_ib_mr *ibmr) 124{ 125 struct rds_ib_frmr *frmr = &ibmr->u.frmr; 126 struct ib_reg_wr reg_wr; 127 int ret, off = 0; 128 129 while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) { 130 atomic_inc(&ibmr->ic->i_fastreg_wrs); 131 cpu_relax(); 132 } 133 134 ret = ib_map_mr_sg_zbva(frmr->mr, ibmr->sg, ibmr->sg_dma_len, 135 &off, PAGE_SIZE); 136 if (unlikely(ret != ibmr->sg_dma_len)) 137 return ret < 0 ? ret : -EINVAL; 138 139 if (cmpxchg(&frmr->fr_state, 140 FRMR_IS_FREE, FRMR_IS_INUSE) != FRMR_IS_FREE) 141 return -EBUSY; 142 143 atomic_inc(&ibmr->ic->i_fastreg_inuse_count); 144 145 /* Perform a WR for the fast_reg_mr. Each individual page 146 * in the sg list is added to the fast reg page list and placed 147 * inside the fast_reg_mr WR. The key used is a rolling 8bit 148 * counter, which should guarantee uniqueness. 149 */ 150 ib_update_fast_reg_key(frmr->mr, ibmr->remap_count++); 151 frmr->fr_reg = true; 152 153 memset(®_wr, 0, sizeof(reg_wr)); 154 reg_wr.wr.wr_id = (unsigned long)(void *)ibmr; 155 reg_wr.wr.opcode = IB_WR_REG_MR; 156 reg_wr.wr.num_sge = 0; 157 reg_wr.mr = frmr->mr; 158 reg_wr.key = frmr->mr->rkey; 159 reg_wr.access = IB_ACCESS_LOCAL_WRITE | 160 IB_ACCESS_REMOTE_READ | 161 IB_ACCESS_REMOTE_WRITE; 162 reg_wr.wr.send_flags = IB_SEND_SIGNALED; 163 164 ret = ib_post_send(ibmr->ic->i_cm_id->qp, ®_wr.wr, NULL); 165 if (unlikely(ret)) { 166 /* Failure here can be because of -ENOMEM as well */ 167 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE); 168 169 atomic_inc(&ibmr->ic->i_fastreg_wrs); 170 if (printk_ratelimit()) 171 pr_warn("RDS/IB: %s returned error(%d)\n", 172 __func__, ret); 173 goto out; 174 } 175 176 /* Wait for the registration to complete in order to prevent an invalid 177 * access error resulting from a race between the memory region already 178 * being accessed while registration is still pending. 179 */ 180 wait_event(frmr->fr_reg_done, !frmr->fr_reg); 181 182out: 183 184 return ret; 185} 186 187static int rds_ib_map_frmr(struct rds_ib_device *rds_ibdev, 188 struct rds_ib_mr_pool *pool, 189 struct rds_ib_mr *ibmr, 190 struct scatterlist *sg, unsigned int sg_len) 191{ 192 struct ib_device *dev = rds_ibdev->dev; 193 struct rds_ib_frmr *frmr = &ibmr->u.frmr; 194 int i; 195 u32 len; 196 int ret = 0; 197 198 /* We want to teardown old ibmr values here and fill it up with 199 * new sg values 200 */ 201 rds_ib_teardown_mr(ibmr); 202 203 ibmr->sg = sg; 204 ibmr->sg_len = sg_len; 205 ibmr->sg_dma_len = 0; 206 frmr->sg_byte_len = 0; 207 WARN_ON(ibmr->sg_dma_len); 208 ibmr->sg_dma_len = ib_dma_map_sg(dev, ibmr->sg, ibmr->sg_len, 209 DMA_BIDIRECTIONAL); 210 if (unlikely(!ibmr->sg_dma_len)) { 211 pr_warn("RDS/IB: %s failed!\n", __func__); 212 return -EBUSY; 213 } 214 215 frmr->sg_byte_len = 0; 216 frmr->dma_npages = 0; 217 len = 0; 218 219 ret = -EINVAL; 220 for (i = 0; i < ibmr->sg_dma_len; ++i) { 221 unsigned int dma_len = sg_dma_len(&ibmr->sg[i]); 222 u64 dma_addr = sg_dma_address(&ibmr->sg[i]); 223 224 frmr->sg_byte_len += dma_len; 225 if (dma_addr & ~PAGE_MASK) { 226 if (i > 0) 227 goto out_unmap; 228 else 229 ++frmr->dma_npages; 230 } 231 232 if ((dma_addr + dma_len) & ~PAGE_MASK) { 233 if (i < ibmr->sg_dma_len - 1) 234 goto out_unmap; 235 else 236 ++frmr->dma_npages; 237 } 238 239 len += dma_len; 240 } 241 frmr->dma_npages += len >> PAGE_SHIFT; 242 243 if (frmr->dma_npages > ibmr->pool->max_pages) { 244 ret = -EMSGSIZE; 245 goto out_unmap; 246 } 247 248 ret = rds_ib_post_reg_frmr(ibmr); 249 if (ret) 250 goto out_unmap; 251 252 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL) 253 rds_ib_stats_inc(s_ib_rdma_mr_8k_used); 254 else 255 rds_ib_stats_inc(s_ib_rdma_mr_1m_used); 256 257 return ret; 258 259out_unmap: 260 ib_dma_unmap_sg(rds_ibdev->dev, ibmr->sg, ibmr->sg_len, 261 DMA_BIDIRECTIONAL); 262 ibmr->sg_dma_len = 0; 263 return ret; 264} 265 266static int rds_ib_post_inv(struct rds_ib_mr *ibmr) 267{ 268 struct ib_send_wr *s_wr; 269 struct rds_ib_frmr *frmr = &ibmr->u.frmr; 270 struct rdma_cm_id *i_cm_id = ibmr->ic->i_cm_id; 271 int ret = -EINVAL; 272 273 if (!i_cm_id || !i_cm_id->qp || !frmr->mr) 274 goto out; 275 276 if (frmr->fr_state != FRMR_IS_INUSE) 277 goto out; 278 279 while (atomic_dec_return(&ibmr->ic->i_fastreg_wrs) <= 0) { 280 atomic_inc(&ibmr->ic->i_fastreg_wrs); 281 cpu_relax(); 282 } 283 284 frmr->fr_inv = true; 285 s_wr = &frmr->fr_wr; 286 287 memset(s_wr, 0, sizeof(*s_wr)); 288 s_wr->wr_id = (unsigned long)(void *)ibmr; 289 s_wr->opcode = IB_WR_LOCAL_INV; 290 s_wr->ex.invalidate_rkey = frmr->mr->rkey; 291 s_wr->send_flags = IB_SEND_SIGNALED; 292 293 ret = ib_post_send(i_cm_id->qp, s_wr, NULL); 294 if (unlikely(ret)) { 295 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE); 296 frmr->fr_inv = false; 297 /* enforce order of frmr->fr_inv update 298 * before incrementing i_fastreg_wrs 299 */ 300 smp_mb__before_atomic(); 301 atomic_inc(&ibmr->ic->i_fastreg_wrs); 302 pr_err("RDS/IB: %s returned error(%d)\n", __func__, ret); 303 goto out; 304 } 305 306 /* Wait for the FRMR_IS_FREE (or FRMR_IS_STALE) transition in order to 307 * 1) avoid a silly bouncing between "clean_list" and "drop_list" 308 * triggered by function "rds_ib_reg_frmr" as it is releases frmr 309 * regions whose state is not "FRMR_IS_FREE" right away. 310 * 2) prevents an invalid access error in a race 311 * from a pending "IB_WR_LOCAL_INV" operation 312 * with a teardown ("dma_unmap_sg", "put_page") 313 * and de-registration ("ib_dereg_mr") of the corresponding 314 * memory region. 315 */ 316 wait_event(frmr->fr_inv_done, frmr->fr_state != FRMR_IS_INUSE); 317 318out: 319 return ret; 320} 321 322void rds_ib_mr_cqe_handler(struct rds_ib_connection *ic, struct ib_wc *wc) 323{ 324 struct rds_ib_mr *ibmr = (void *)(unsigned long)wc->wr_id; 325 struct rds_ib_frmr *frmr = &ibmr->u.frmr; 326 327 if (wc->status != IB_WC_SUCCESS) { 328 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_STALE); 329 if (rds_conn_up(ic->conn)) 330 rds_ib_conn_error(ic->conn, 331 "frmr completion <%pI4,%pI4> status %u(%s), vendor_err 0x%x, disconnecting and reconnecting\n", 332 &ic->conn->c_laddr, 333 &ic->conn->c_faddr, 334 wc->status, 335 ib_wc_status_msg(wc->status), 336 wc->vendor_err); 337 } 338 339 if (frmr->fr_inv) { 340 rds_transition_frwr_state(ibmr, FRMR_IS_INUSE, FRMR_IS_FREE); 341 frmr->fr_inv = false; 342 wake_up(&frmr->fr_inv_done); 343 } 344 345 if (frmr->fr_reg) { 346 frmr->fr_reg = false; 347 wake_up(&frmr->fr_reg_done); 348 } 349 350 /* enforce order of frmr->{fr_reg,fr_inv} update 351 * before incrementing i_fastreg_wrs 352 */ 353 smp_mb__before_atomic(); 354 atomic_inc(&ic->i_fastreg_wrs); 355} 356 357void rds_ib_unreg_frmr(struct list_head *list, unsigned int *nfreed, 358 unsigned long *unpinned, unsigned int goal) 359{ 360 struct rds_ib_mr *ibmr, *next; 361 struct rds_ib_frmr *frmr; 362 int ret = 0, ret2; 363 unsigned int freed = *nfreed; 364 365 /* String all ib_mr's onto one list and hand them to ib_unmap_fmr */ 366 list_for_each_entry(ibmr, list, unmap_list) { 367 if (ibmr->sg_dma_len) { 368 ret2 = rds_ib_post_inv(ibmr); 369 if (ret2 && !ret) 370 ret = ret2; 371 } 372 } 373 374 if (ret) 375 pr_warn("RDS/IB: %s failed (err=%d)\n", __func__, ret); 376 377 /* Now we can destroy the DMA mapping and unpin any pages */ 378 list_for_each_entry_safe(ibmr, next, list, unmap_list) { 379 *unpinned += ibmr->sg_len; 380 frmr = &ibmr->u.frmr; 381 __rds_ib_teardown_mr(ibmr); 382 if (freed < goal || frmr->fr_state == FRMR_IS_STALE) { 383 /* Don't de-allocate if the MR is not free yet */ 384 if (frmr->fr_state == FRMR_IS_INUSE) 385 continue; 386 387 if (ibmr->pool->pool_type == RDS_IB_MR_8K_POOL) 388 rds_ib_stats_inc(s_ib_rdma_mr_8k_free); 389 else 390 rds_ib_stats_inc(s_ib_rdma_mr_1m_free); 391 list_del(&ibmr->unmap_list); 392 if (frmr->mr) 393 ib_dereg_mr(frmr->mr); 394 kfree(ibmr); 395 freed++; 396 } 397 } 398 *nfreed = freed; 399} 400 401struct rds_ib_mr *rds_ib_reg_frmr(struct rds_ib_device *rds_ibdev, 402 struct rds_ib_connection *ic, 403 struct scatterlist *sg, 404 unsigned long nents, u32 *key) 405{ 406 struct rds_ib_mr *ibmr = NULL; 407 struct rds_ib_frmr *frmr; 408 int ret; 409 410 if (!ic) { 411 /* TODO: Add FRWR support for RDS_GET_MR using proxy qp*/ 412 return ERR_PTR(-EOPNOTSUPP); 413 } 414 415 do { 416 if (ibmr) 417 rds_ib_free_frmr(ibmr, true); 418 ibmr = rds_ib_alloc_frmr(rds_ibdev, nents); 419 if (IS_ERR(ibmr)) 420 return ibmr; 421 frmr = &ibmr->u.frmr; 422 } while (frmr->fr_state != FRMR_IS_FREE); 423 424 ibmr->ic = ic; 425 ibmr->device = rds_ibdev; 426 ret = rds_ib_map_frmr(rds_ibdev, ibmr->pool, ibmr, sg, nents); 427 if (ret == 0) { 428 *key = frmr->mr->rkey; 429 } else { 430 rds_ib_free_frmr(ibmr, false); 431 ibmr = ERR_PTR(ret); 432 } 433 434 return ibmr; 435} 436 437void rds_ib_free_frmr_list(struct rds_ib_mr *ibmr) 438{ 439 struct rds_ib_mr_pool *pool = ibmr->pool; 440 struct rds_ib_frmr *frmr = &ibmr->u.frmr; 441 442 if (frmr->fr_state == FRMR_IS_STALE) 443 llist_add(&ibmr->llnode, &pool->drop_list); 444 else 445 llist_add(&ibmr->llnode, &pool->free_list); 446} 447