drivers/nvme/target/rdma.c

   1 /*
   2  * NVMe over Fabrics RDMA target.
   3  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15 #include <linux/atomic.h>
  16 #include <linux/ctype.h>
  17 #include <linux/delay.h>
  18 #include <linux/err.h>
  19 #include <linux/init.h>
  20 #include <linux/module.h>
  21 #include <linux/nvme.h>
  22 #include <linux/slab.h>
  23 #include <linux/string.h>
  24 #include <linux/wait.h>
  25 #include <linux/inet.h>
  26 #include <asm/unaligned.h>
  27
  28 #include <rdma/ib_verbs.h>
  29 #include <rdma/rdma_cm.h>
  30 #include <rdma/rw.h>
  31
  32 #include <linux/nvme-rdma.h>
  33 #include "nvmet.h"
  34
  35 /*
  36  * We allow at least 1 page, up to 4 SGEs, and up to 16KB of inline data
  37  */
  38 #define NVMET_RDMA_DEFAULT_INLINE_DATA_SIZE     PAGE_SIZE
  39 #define NVMET_RDMA_MAX_INLINE_SGE               4
  40 #define NVMET_RDMA_MAX_INLINE_DATA_SIZE         max_t(int, SZ_16K, PAGE_SIZE)
  41
  42 struct nvmet_rdma_cmd {
  43         struct ib_sge           sge[NVMET_RDMA_MAX_INLINE_SGE + 1];
  44         struct ib_cqe           cqe;
  45         struct ib_recv_wr       wr;
  46         struct scatterlist      inline_sg[NVMET_RDMA_MAX_INLINE_SGE];
  47         struct nvme_command     *nvme_cmd;
  48         struct nvmet_rdma_queue *queue;
  49 };
  50
  51 enum {
  52         NVMET_RDMA_REQ_INLINE_DATA      = (1 << 0),
  53         NVMET_RDMA_REQ_INVALIDATE_RKEY  = (1 << 1),
  54 };
  55
  56 struct nvmet_rdma_rsp {
  57         struct ib_sge           send_sge;
  58         struct ib_cqe           send_cqe;
  59         struct ib_send_wr       send_wr;
  60
  61         struct nvmet_rdma_cmd   *cmd;
  62         struct nvmet_rdma_queue *queue;
  63
  64         struct ib_cqe           read_cqe;
  65         struct rdma_rw_ctx      rw;
  66
  67         struct nvmet_req        req;
  68
  69         u8                      n_rdma;
  70         u32                     flags;
  71         u32                     invalidate_rkey;
  72
  73         struct list_head        wait_list;
  74         struct list_head        free_list;
  75 };
  76
  77 enum nvmet_rdma_queue_state {
  78         NVMET_RDMA_Q_CONNECTING,
  79         NVMET_RDMA_Q_LIVE,
  80         NVMET_RDMA_Q_DISCONNECTING,
  81 };
  82
  83 struct nvmet_rdma_queue {
  84         struct rdma_cm_id       *cm_id;
  85         struct nvmet_port       *port;
  86         struct ib_cq            *cq;
  87         atomic_t                sq_wr_avail;
  88         struct nvmet_rdma_device *dev;
  89         spinlock_t              state_lock;
  90         enum nvmet_rdma_queue_state state;
  91         struct nvmet_cq         nvme_cq;
  92         struct nvmet_sq         nvme_sq;
  93
  94         struct nvmet_rdma_rsp   *rsps;
  95         struct list_head        free_rsps;
  96         spinlock_t              rsps_lock;
  97         struct nvmet_rdma_cmd   *cmds;
  98
  99         struct work_struct      release_work;
 100         struct list_head        rsp_wait_list;
 101         struct list_head        rsp_wr_wait_list;
 102         spinlock_t              rsp_wr_wait_lock;
 103
 104         int                     idx;
 105         int                     host_qid;
 106         int                     recv_queue_size;
 107         int                     send_queue_size;
 108
 109         struct list_head        queue_list;
 110 };
 111
 112 struct nvmet_rdma_device {
 113         struct ib_device        *device;
 114         struct ib_pd            *pd;
 115         struct ib_srq           *srq;
 116         struct nvmet_rdma_cmd   *srq_cmds;
 117         size_t                  srq_size;
 118         struct kref             ref;
 119         struct list_head        entry;
 120         int                     inline_data_size;
 121         int                     inline_page_count;
 122 };
 123
 124 static bool nvmet_rdma_use_srq;
 125 module_param_named(use_srq, nvmet_rdma_use_srq, bool, 0444);
 126 MODULE_PARM_DESC(use_srq, "Use shared receive queue.");
 127
 128 static DEFINE_IDA(nvmet_rdma_queue_ida);
 129 static LIST_HEAD(nvmet_rdma_queue_list);
 130 static DEFINE_MUTEX(nvmet_rdma_queue_mutex);
 131
 132 static LIST_HEAD(device_list);
 133 static DEFINE_MUTEX(device_list_mutex);
 134
 135 static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp);
 136 static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc);
 137 static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc);
 138 static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc);
 139 static void nvmet_rdma_qp_event(struct ib_event *event, void *priv);
 140 static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue);
 141
 142 static const struct nvmet_fabrics_ops nvmet_rdma_ops;
 143
 144 static int num_pages(int len)
 145 {
 146         return 1 + (((len - 1) & PAGE_MASK) >> PAGE_SHIFT);
 147 }
 148
 149 /* XXX: really should move to a generic header sooner or later.. */
 150 static inline u32 get_unaligned_le24(const u8 *p)
 151 {
 152         return (u32)p[0] | (u32)p[1] << 8 | (u32)p[2] << 16;
 153 }
 154
 155 static inline bool nvmet_rdma_need_data_in(struct nvmet_rdma_rsp *rsp)
 156 {
 157         return nvme_is_write(rsp->req.cmd) &&
 158                 rsp->req.transfer_len &&
 159                 !(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
 160 }
 161
 162 static inline bool nvmet_rdma_need_data_out(struct nvmet_rdma_rsp *rsp)
 163 {
 164         return !nvme_is_write(rsp->req.cmd) &&
 165                 rsp->req.transfer_len &&
 166                 !rsp->req.rsp->status &&
 167                 !(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
 168 }
 169
 170 static inline struct nvmet_rdma_rsp *
 171 nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue)
 172 {
 173         struct nvmet_rdma_rsp *rsp;
 174         unsigned long flags;
 175
 176         spin_lock_irqsave(&queue->rsps_lock, flags);
 177         rsp = list_first_entry(&queue->free_rsps,
 178                                 struct nvmet_rdma_rsp, free_list);
 179         list_del(&rsp->free_list);
 180         spin_unlock_irqrestore(&queue->rsps_lock, flags);
 181
 182         return rsp;
 183 }
 184
 185 static inline void
 186 nvmet_rdma_put_rsp(struct nvmet_rdma_rsp *rsp)
 187 {
 188         unsigned long flags;
 189
 190         spin_lock_irqsave(&rsp->queue->rsps_lock, flags);
 191         list_add_tail(&rsp->free_list, &rsp->queue->free_rsps);
 192         spin_unlock_irqrestore(&rsp->queue->rsps_lock, flags);
 193 }
 194
 195 static void nvmet_rdma_free_inline_pages(struct nvmet_rdma_device *ndev,
 196                                 struct nvmet_rdma_cmd *c)
 197 {
 198         struct scatterlist *sg;
 199         struct ib_sge *sge;
 200         int i;
 201
 202         if (!ndev->inline_data_size)
 203                 return;
 204
 205         sg = c->inline_sg;
 206         sge = &c->sge[1];
 207
 208         for (i = 0; i < ndev->inline_page_count; i++, sg++, sge++) {
 209                 if (sge->length)
 210                         ib_dma_unmap_page(ndev->device, sge->addr,
 211                                         sge->length, DMA_FROM_DEVICE);
 212                 if (sg_page(sg))
 213                         __free_page(sg_page(sg));
 214         }
 215 }
 216
 217 static int nvmet_rdma_alloc_inline_pages(struct nvmet_rdma_device *ndev,
 218                                 struct nvmet_rdma_cmd *c)
 219 {
 220         struct scatterlist *sg;
 221         struct ib_sge *sge;
 222         struct page *pg;
 223         int len;
 224         int i;
 225
 226         if (!ndev->inline_data_size)
 227                 return 0;
 228
 229         sg = c->inline_sg;
 230         sg_init_table(sg, ndev->inline_page_count);
 231         sge = &c->sge[1];
 232         len = ndev->inline_data_size;
 233
 234         for (i = 0; i < ndev->inline_page_count; i++, sg++, sge++) {
 235                 pg = alloc_page(GFP_KERNEL);
 236                 if (!pg)
 237                         goto out_err;
 238                 sg_assign_page(sg, pg);
 239                 sge->addr = ib_dma_map_page(ndev->device,
 240                         pg, 0, PAGE_SIZE, DMA_FROM_DEVICE);
 241                 if (ib_dma_mapping_error(ndev->device, sge->addr))
 242                         goto out_err;
 243                 sge->length = min_t(int, len, PAGE_SIZE);
 244                 sge->lkey = ndev->pd->local_dma_lkey;
 245                 len -= sge->length;
 246         }
 247
 248         return 0;
 249 out_err:
 250         for (; i >= 0; i--, sg--, sge--) {
 251                 if (sge->length)
 252                         ib_dma_unmap_page(ndev->device, sge->addr,
 253                                         sge->length, DMA_FROM_DEVICE);
 254                 if (sg_page(sg))
 255                         __free_page(sg_page(sg));
 256         }
 257         return -ENOMEM;
 258 }
 259
 260 static int nvmet_rdma_alloc_cmd(struct nvmet_rdma_device *ndev,
 261                         struct nvmet_rdma_cmd *c, bool admin)
 262 {
 263         /* NVMe command / RDMA RECV */
 264         c->nvme_cmd = kmalloc(sizeof(*c->nvme_cmd), GFP_KERNEL);
 265         if (!c->nvme_cmd)
 266                 goto out;
 267
 268         c->sge[0].addr = ib_dma_map_single(ndev->device, c->nvme_cmd,
 269                         sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
 270         if (ib_dma_mapping_error(ndev->device, c->sge[0].addr))
 271                 goto out_free_cmd;
 272
 273         c->sge[0].length = sizeof(*c->nvme_cmd);
 274         c->sge[0].lkey = ndev->pd->local_dma_lkey;
 275
 276         if (!admin && nvmet_rdma_alloc_inline_pages(ndev, c))
 277                 goto out_unmap_cmd;
 278
 279         c->cqe.done = nvmet_rdma_recv_done;
 280
 281         c->wr.wr_cqe = &c->cqe;
 282         c->wr.sg_list = c->sge;
 283         c->wr.num_sge = admin ? 1 : ndev->inline_page_count + 1;
 284
 285         return 0;
 286
 287 out_unmap_cmd:
 288         ib_dma_unmap_single(ndev->device, c->sge[0].addr,
 289                         sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
 290 out_free_cmd:
 291         kfree(c->nvme_cmd);
 292
 293 out:
 294         return -ENOMEM;
 295 }
 296
 297 static void nvmet_rdma_free_cmd(struct nvmet_rdma_device *ndev,
 298                 struct nvmet_rdma_cmd *c, bool admin)
 299 {
 300         if (!admin)
 301                 nvmet_rdma_free_inline_pages(ndev, c);
 302         ib_dma_unmap_single(ndev->device, c->sge[0].addr,
 303                                 sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
 304         kfree(c->nvme_cmd);
 305 }
 306
 307 static struct nvmet_rdma_cmd *
 308 nvmet_rdma_alloc_cmds(struct nvmet_rdma_device *ndev,
 309                 int nr_cmds, bool admin)
 310 {
 311         struct nvmet_rdma_cmd *cmds;
 312         int ret = -EINVAL, i;
 313
 314         cmds = kcalloc(nr_cmds, sizeof(struct nvmet_rdma_cmd), GFP_KERNEL);
 315         if (!cmds)
 316                 goto out;
 317
 318         for (i = 0; i < nr_cmds; i++) {
 319                 ret = nvmet_rdma_alloc_cmd(ndev, cmds + i, admin);
 320                 if (ret)
 321                         goto out_free;
 322         }
 323
 324         return cmds;
 325
 326 out_free:
 327         while (--i >= 0)
 328                 nvmet_rdma_free_cmd(ndev, cmds + i, admin);
 329         kfree(cmds);
 330 out:
 331         return ERR_PTR(ret);
 332 }
 333
 334 static void nvmet_rdma_free_cmds(struct nvmet_rdma_device *ndev,
 335                 struct nvmet_rdma_cmd *cmds, int nr_cmds, bool admin)
 336 {
 337         int i;
 338
 339         for (i = 0; i < nr_cmds; i++)
 340                 nvmet_rdma_free_cmd(ndev, cmds + i, admin);
 341         kfree(cmds);
 342 }
 343
 344 static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev,
 345                 struct nvmet_rdma_rsp *r)
 346 {
 347         /* NVMe CQE / RDMA SEND */
 348         r->req.rsp = kmalloc(sizeof(*r->req.rsp), GFP_KERNEL);
 349         if (!r->req.rsp)
 350                 goto out;
 351
 352         r->send_sge.addr = ib_dma_map_single(ndev->device, r->req.rsp,
 353                         sizeof(*r->req.rsp), DMA_TO_DEVICE);
 354         if (ib_dma_mapping_error(ndev->device, r->send_sge.addr))
 355                 goto out_free_rsp;
 356
 357         r->send_sge.length = sizeof(*r->req.rsp);
 358         r->send_sge.lkey = ndev->pd->local_dma_lkey;
 359
 360         r->send_cqe.done = nvmet_rdma_send_done;
 361
 362         r->send_wr.wr_cqe = &r->send_cqe;
 363         r->send_wr.sg_list = &r->send_sge;
 364         r->send_wr.num_sge = 1;
 365         r->send_wr.send_flags = IB_SEND_SIGNALED;
 366
 367         /* Data In / RDMA READ */
 368         r->read_cqe.done = nvmet_rdma_read_data_done;
 369         return 0;
 370
 371 out_free_rsp:
 372         kfree(r->req.rsp);
 373 out:
 374         return -ENOMEM;
 375 }
 376
 377 static void nvmet_rdma_free_rsp(struct nvmet_rdma_device *ndev,
 378                 struct nvmet_rdma_rsp *r)
 379 {
 380         ib_dma_unmap_single(ndev->device, r->send_sge.addr,
 381                                 sizeof(*r->req.rsp), DMA_TO_DEVICE);
 382         kfree(r->req.rsp);
 383 }
 384
 385 static int
 386 nvmet_rdma_alloc_rsps(struct nvmet_rdma_queue *queue)
 387 {
 388         struct nvmet_rdma_device *ndev = queue->dev;
 389         int nr_rsps = queue->recv_queue_size * 2;
 390         int ret = -EINVAL, i;
 391
 392         queue->rsps = kcalloc(nr_rsps, sizeof(struct nvmet_rdma_rsp),
 393                         GFP_KERNEL);
 394         if (!queue->rsps)
 395                 goto out;
 396
 397         for (i = 0; i < nr_rsps; i++) {
 398                 struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
 399
 400                 ret = nvmet_rdma_alloc_rsp(ndev, rsp);
 401                 if (ret)
 402                         goto out_free;
 403
 404                 list_add_tail(&rsp->free_list, &queue->free_rsps);
 405         }
 406
 407         return 0;
 408
 409 out_free:
 410         while (--i >= 0) {
 411                 struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
 412
 413                 list_del(&rsp->free_list);
 414                 nvmet_rdma_free_rsp(ndev, rsp);
 415         }
 416         kfree(queue->rsps);
 417 out:
 418         return ret;
 419 }
 420
 421 static void nvmet_rdma_free_rsps(struct nvmet_rdma_queue *queue)
 422 {
 423         struct nvmet_rdma_device *ndev = queue->dev;
 424         int i, nr_rsps = queue->recv_queue_size * 2;
 425
 426         for (i = 0; i < nr_rsps; i++) {
 427                 struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
 428
 429                 list_del(&rsp->free_list);
 430                 nvmet_rdma_free_rsp(ndev, rsp);
 431         }
 432         kfree(queue->rsps);
 433 }
 434
 435 static int nvmet_rdma_post_recv(struct nvmet_rdma_device *ndev,
 436                 struct nvmet_rdma_cmd *cmd)
 437 {
 438         int ret;
 439
 440         ib_dma_sync_single_for_device(ndev->device,
 441                 cmd->sge[0].addr, cmd->sge[0].length,
 442                 DMA_FROM_DEVICE);
 443
 444         if (ndev->srq)
 445                 ret = ib_post_srq_recv(ndev->srq, &cmd->wr, NULL);
 446         else
 447                 ret = ib_post_recv(cmd->queue->cm_id->qp, &cmd->wr, NULL);
 448
 449         if (unlikely(ret))
 450                 pr_err("post_recv cmd failed\n");
 451
 452         return ret;
 453 }
 454
 455 static void nvmet_rdma_process_wr_wait_list(struct nvmet_rdma_queue *queue)
 456 {
 457         spin_lock(&queue->rsp_wr_wait_lock);
 458         while (!list_empty(&queue->rsp_wr_wait_list)) {
 459                 struct nvmet_rdma_rsp *rsp;
 460                 bool ret;
 461
 462                 rsp = list_entry(queue->rsp_wr_wait_list.next,
 463                                 struct nvmet_rdma_rsp, wait_list);
 464                 list_del(&rsp->wait_list);
 465
 466                 spin_unlock(&queue->rsp_wr_wait_lock);
 467                 ret = nvmet_rdma_execute_command(rsp);
 468                 spin_lock(&queue->rsp_wr_wait_lock);
 469
 470                 if (!ret) {
 471                         list_add(&rsp->wait_list, &queue->rsp_wr_wait_list);
 472                         break;
 473                 }
 474         }
 475         spin_unlock(&queue->rsp_wr_wait_lock);
 476 }
 477
 478
 479 static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp)
 480 {
 481         struct nvmet_rdma_queue *queue = rsp->queue;
 482
 483         atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
 484
 485         if (rsp->n_rdma) {
 486                 rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
 487                                 queue->cm_id->port_num, rsp->req.sg,
 488                                 rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
 489         }
 490
 491         if (rsp->req.sg != rsp->cmd->inline_sg)
 492                 sgl_free(rsp->req.sg);
 493
 494         if (unlikely(!list_empty_careful(&queue->rsp_wr_wait_list)))
 495                 nvmet_rdma_process_wr_wait_list(queue);
 496
 497         nvmet_rdma_put_rsp(rsp);
 498 }
 499
 500 static void nvmet_rdma_error_comp(struct nvmet_rdma_queue *queue)
 501 {
 502         if (queue->nvme_sq.ctrl) {
 503                 nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
 504         } else {
 505                 /*
 506                  * we didn't setup the controller yet in case
 507                  * of admin connect error, just disconnect and
 508                  * cleanup the queue
 509                  */
 510                 nvmet_rdma_queue_disconnect(queue);
 511         }
 512 }
 513
 514 static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
 515 {
 516         struct nvmet_rdma_rsp *rsp =
 517                 container_of(wc->wr_cqe, struct nvmet_rdma_rsp, send_cqe);
 518
 519         nvmet_rdma_release_rsp(rsp);
 520
 521         if (unlikely(wc->status != IB_WC_SUCCESS &&
 522                      wc->status != IB_WC_WR_FLUSH_ERR)) {
 523                 pr_err("SEND for CQE 0x%p failed with status %s (%d).\n",
 524                         wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
 525                 nvmet_rdma_error_comp(rsp->queue);
 526         }
 527 }
 528
 529 static void nvmet_rdma_queue_response(struct nvmet_req *req)
 530 {
 531         struct nvmet_rdma_rsp *rsp =
 532                 container_of(req, struct nvmet_rdma_rsp, req);
 533         struct rdma_cm_id *cm_id = rsp->queue->cm_id;
 534         struct ib_send_wr *first_wr;
 535
 536         if (rsp->flags & NVMET_RDMA_REQ_INVALIDATE_RKEY) {
 537                 rsp->send_wr.opcode = IB_WR_SEND_WITH_INV;
 538                 rsp->send_wr.ex.invalidate_rkey = rsp->invalidate_rkey;
 539         } else {
 540                 rsp->send_wr.opcode = IB_WR_SEND;
 541         }
 542
 543         if (nvmet_rdma_need_data_out(rsp))
 544                 first_wr = rdma_rw_ctx_wrs(&rsp->rw, cm_id->qp,
 545                                 cm_id->port_num, NULL, &rsp->send_wr);
 546         else
 547                 first_wr = &rsp->send_wr;
 548
 549         nvmet_rdma_post_recv(rsp->queue->dev, rsp->cmd);
 550
 551         ib_dma_sync_single_for_device(rsp->queue->dev->device,
 552                 rsp->send_sge.addr, rsp->send_sge.length,
 553                 DMA_TO_DEVICE);
 554
 555         if (unlikely(ib_post_send(cm_id->qp, first_wr, NULL))) {
 556                 pr_err("sending cmd response failed\n");
 557                 nvmet_rdma_release_rsp(rsp);
 558         }
 559 }
 560
 561 static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc)
 562 {
 563         struct nvmet_rdma_rsp *rsp =
 564                 container_of(wc->wr_cqe, struct nvmet_rdma_rsp, read_cqe);
 565         struct nvmet_rdma_queue *queue = cq->cq_context;
 566
 567         WARN_ON(rsp->n_rdma <= 0);
 568         atomic_add(rsp->n_rdma, &queue->sq_wr_avail);
 569         rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
 570                         queue->cm_id->port_num, rsp->req.sg,
 571                         rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
 572         rsp->n_rdma = 0;
 573
 574         if (unlikely(wc->status != IB_WC_SUCCESS)) {
 575                 nvmet_req_uninit(&rsp->req);
 576                 nvmet_rdma_release_rsp(rsp);
 577                 if (wc->status != IB_WC_WR_FLUSH_ERR) {
 578                         pr_info("RDMA READ for CQE 0x%p failed with status %s (%d).\n",
 579                                 wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
 580                         nvmet_rdma_error_comp(queue);
 581                 }
 582                 return;
 583         }
 584
 585         nvmet_req_execute(&rsp->req);
 586 }
 587
 588 static void nvmet_rdma_use_inline_sg(struct nvmet_rdma_rsp *rsp, u32 len,
 589                 u64 off)
 590 {
 591         int sg_count = num_pages(len);
 592         struct scatterlist *sg;
 593         int i;
 594
 595         sg = rsp->cmd->inline_sg;
 596         for (i = 0; i < sg_count; i++, sg++) {
 597                 if (i < sg_count - 1)
 598                         sg_unmark_end(sg);
 599                 else
 600                         sg_mark_end(sg);
 601                 sg->offset = off;
 602                 sg->length = min_t(int, len, PAGE_SIZE - off);
 603                 len -= sg->length;
 604                 if (!i)
 605                         off = 0;
 606         }
 607
 608         rsp->req.sg = rsp->cmd->inline_sg;
 609         rsp->req.sg_cnt = sg_count;
 610 }
 611
 612 static u16 nvmet_rdma_map_sgl_inline(struct nvmet_rdma_rsp *rsp)
 613 {
 614         struct nvme_sgl_desc *sgl = &rsp->req.cmd->common.dptr.sgl;
 615         u64 off = le64_to_cpu(sgl->addr);
 616         u32 len = le32_to_cpu(sgl->length);
 617
 618         if (!nvme_is_write(rsp->req.cmd))
 619                 return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 620
 621         if (off + len > rsp->queue->dev->inline_data_size) {
 622                 pr_err("invalid inline data offset!\n");
 623                 return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
 624         }
 625
 626         /* no data command? */
 627         if (!len)
 628                 return 0;
 629
 630         nvmet_rdma_use_inline_sg(rsp, len, off);
 631         rsp->flags |= NVMET_RDMA_REQ_INLINE_DATA;
 632         rsp->req.transfer_len += len;
 633         return 0;
 634 }
 635
 636 static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp,
 637                 struct nvme_keyed_sgl_desc *sgl, bool invalidate)
 638 {
 639         struct rdma_cm_id *cm_id = rsp->queue->cm_id;
 640         u64 addr = le64_to_cpu(sgl->addr);
 641         u32 len = get_unaligned_le24(sgl->length);
 642         u32 key = get_unaligned_le32(sgl->key);
 643         int ret;
 644
 645         /* no data command? */
 646         if (!len)
 647                 return 0;
 648
 649         rsp->req.sg = sgl_alloc(len, GFP_KERNEL, &rsp->req.sg_cnt);
 650         if (!rsp->req.sg)
 651                 return NVME_SC_INTERNAL;
 652
 653         ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num,
 654                         rsp->req.sg, rsp->req.sg_cnt, 0, addr, key,
 655                         nvmet_data_dir(&rsp->req));
 656         if (ret < 0)
 657                 return NVME_SC_INTERNAL;
 658         rsp->req.transfer_len += len;
 659         rsp->n_rdma += ret;
 660
 661         if (invalidate) {
 662                 rsp->invalidate_rkey = key;
 663                 rsp->flags |= NVMET_RDMA_REQ_INVALIDATE_RKEY;
 664         }
 665
 666         return 0;
 667 }
 668
 669 static u16 nvmet_rdma_map_sgl(struct nvmet_rdma_rsp *rsp)
 670 {
 671         struct nvme_keyed_sgl_desc *sgl = &rsp->req.cmd->common.dptr.ksgl;
 672
 673         switch (sgl->type >> 4) {
 674         case NVME_SGL_FMT_DATA_DESC:
 675                 switch (sgl->type & 0xf) {
 676                 case NVME_SGL_FMT_OFFSET:
 677                         return nvmet_rdma_map_sgl_inline(rsp);
 678                 default:
 679                         pr_err("invalid SGL subtype: %#x\n", sgl->type);
 680                         return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 681                 }
 682         case NVME_KEY_SGL_FMT_DATA_DESC:
 683                 switch (sgl->type & 0xf) {
 684                 case NVME_SGL_FMT_ADDRESS | NVME_SGL_FMT_INVALIDATE:
 685                         return nvmet_rdma_map_sgl_keyed(rsp, sgl, true);
 686                 case NVME_SGL_FMT_ADDRESS:
 687                         return nvmet_rdma_map_sgl_keyed(rsp, sgl, false);
 688                 default:
 689                         pr_err("invalid SGL subtype: %#x\n", sgl->type);
 690                         return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
 691                 }
 692         default:
 693                 pr_err("invalid SGL type: %#x\n", sgl->type);
 694                 return NVME_SC_SGL_INVALID_TYPE | NVME_SC_DNR;
 695         }
 696 }
 697
 698 static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp)
 699 {
 700         struct nvmet_rdma_queue *queue = rsp->queue;
 701
 702         if (unlikely(atomic_sub_return(1 + rsp->n_rdma,
 703                         &queue->sq_wr_avail) < 0)) {
 704                 pr_debug("IB send queue full (needed %d): queue %u cntlid %u\n",
 705                                 1 + rsp->n_rdma, queue->idx,
 706                                 queue->nvme_sq.ctrl->cntlid);
 707                 atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
 708                 return false;
 709         }
 710
 711         if (nvmet_rdma_need_data_in(rsp)) {
 712                 if (rdma_rw_ctx_post(&rsp->rw, queue->cm_id->qp,
 713                                 queue->cm_id->port_num, &rsp->read_cqe, NULL))
 714                         nvmet_req_complete(&rsp->req, NVME_SC_DATA_XFER_ERROR);
 715         } else {
 716                 nvmet_req_execute(&rsp->req);
 717         }
 718
 719         return true;
 720 }
 721
 722 static void nvmet_rdma_handle_command(struct nvmet_rdma_queue *queue,
 723                 struct nvmet_rdma_rsp *cmd)
 724 {
 725         u16 status;
 726
 727         ib_dma_sync_single_for_cpu(queue->dev->device,
 728                 cmd->cmd->sge[0].addr, cmd->cmd->sge[0].length,
 729                 DMA_FROM_DEVICE);
 730         ib_dma_sync_single_for_cpu(queue->dev->device,
 731                 cmd->send_sge.addr, cmd->send_sge.length,
 732                 DMA_TO_DEVICE);
 733
 734         if (!nvmet_req_init(&cmd->req, &queue->nvme_cq,
 735                         &queue->nvme_sq, &nvmet_rdma_ops))
 736                 return;
 737
 738         status = nvmet_rdma_map_sgl(cmd);
 739         if (status)
 740                 goto out_err;
 741
 742         if (unlikely(!nvmet_rdma_execute_command(cmd))) {
 743                 spin_lock(&queue->rsp_wr_wait_lock);
 744                 list_add_tail(&cmd->wait_list, &queue->rsp_wr_wait_list);
 745                 spin_unlock(&queue->rsp_wr_wait_lock);
 746         }
 747
 748         return;
 749
 750 out_err:
 751         nvmet_req_complete(&cmd->req, status);
 752 }
 753
 754 static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
 755 {
 756         struct nvmet_rdma_cmd *cmd =
 757                 container_of(wc->wr_cqe, struct nvmet_rdma_cmd, cqe);
 758         struct nvmet_rdma_queue *queue = cq->cq_context;
 759         struct nvmet_rdma_rsp *rsp;
 760
 761         if (unlikely(wc->status != IB_WC_SUCCESS)) {
 762                 if (wc->status != IB_WC_WR_FLUSH_ERR) {
 763                         pr_err("RECV for CQE 0x%p failed with status %s (%d)\n",
 764                                 wc->wr_cqe, ib_wc_status_msg(wc->status),
 765                                 wc->status);
 766                         nvmet_rdma_error_comp(queue);
 767                 }
 768                 return;
 769         }
 770
 771         if (unlikely(wc->byte_len < sizeof(struct nvme_command))) {
 772                 pr_err("Ctrl Fatal Error: capsule size less than 64 bytes\n");
 773                 nvmet_rdma_error_comp(queue);
 774                 return;
 775         }
 776
 777         cmd->queue = queue;
 778         rsp = nvmet_rdma_get_rsp(queue);
 779         rsp->queue = queue;
 780         rsp->cmd = cmd;
 781         rsp->flags = 0;
 782         rsp->req.cmd = cmd->nvme_cmd;
 783         rsp->req.port = queue->port;
 784         rsp->n_rdma = 0;
 785
 786         if (unlikely(queue->state != NVMET_RDMA_Q_LIVE)) {
 787                 unsigned long flags;
 788
 789                 spin_lock_irqsave(&queue->state_lock, flags);
 790                 if (queue->state == NVMET_RDMA_Q_CONNECTING)
 791                         list_add_tail(&rsp->wait_list, &queue->rsp_wait_list);
 792                 else
 793                         nvmet_rdma_put_rsp(rsp);
 794                 spin_unlock_irqrestore(&queue->state_lock, flags);
 795                 return;
 796         }
 797
 798         nvmet_rdma_handle_command(queue, rsp);
 799 }
 800
 801 static void nvmet_rdma_destroy_srq(struct nvmet_rdma_device *ndev)
 802 {
 803         if (!ndev->srq)
 804                 return;
 805
 806         nvmet_rdma_free_cmds(ndev, ndev->srq_cmds, ndev->srq_size, false);
 807         ib_destroy_srq(ndev->srq);
 808 }
 809
 810 static int nvmet_rdma_init_srq(struct nvmet_rdma_device *ndev)
 811 {
 812         struct ib_srq_init_attr srq_attr = { NULL, };
 813         struct ib_srq *srq;
 814         size_t srq_size;
 815         int ret, i;
 816
 817         srq_size = 4095;        /* XXX: tune */
 818
 819         srq_attr.attr.max_wr = srq_size;
 820         srq_attr.attr.max_sge = 1 + ndev->inline_page_count;
 821         srq_attr.attr.srq_limit = 0;
 822         srq_attr.srq_type = IB_SRQT_BASIC;
 823         srq = ib_create_srq(ndev->pd, &srq_attr);
 824         if (IS_ERR(srq)) {
 825                 /*
 826                  * If SRQs aren't supported we just go ahead and use normal
 827                  * non-shared receive queues.
 828                  */
 829                 pr_info("SRQ requested but not supported.\n");
 830                 return 0;
 831         }
 832
 833         ndev->srq_cmds = nvmet_rdma_alloc_cmds(ndev, srq_size, false);
 834         if (IS_ERR(ndev->srq_cmds)) {
 835                 ret = PTR_ERR(ndev->srq_cmds);
 836                 goto out_destroy_srq;
 837         }
 838
 839         ndev->srq = srq;
 840         ndev->srq_size = srq_size;
 841
 842         for (i = 0; i < srq_size; i++) {
 843                 ret = nvmet_rdma_post_recv(ndev, &ndev->srq_cmds[i]);
 844                 if (ret)
 845                         goto out_free_cmds;
 846         }
 847
 848         return 0;
 849
 850 out_free_cmds:
 851         nvmet_rdma_free_cmds(ndev, ndev->srq_cmds, ndev->srq_size, false);
 852 out_destroy_srq:
 853         ib_destroy_srq(srq);
 854         return ret;
 855 }
 856
 857 static void nvmet_rdma_free_dev(struct kref *ref)
 858 {
 859         struct nvmet_rdma_device *ndev =
 860                 container_of(ref, struct nvmet_rdma_device, ref);
 861
 862         mutex_lock(&device_list_mutex);
 863         list_del(&ndev->entry);
 864         mutex_unlock(&device_list_mutex);
 865
 866         nvmet_rdma_destroy_srq(ndev);
 867         ib_dealloc_pd(ndev->pd);
 868
 869         kfree(ndev);
 870 }
 871
 872 static struct nvmet_rdma_device *
 873 nvmet_rdma_find_get_device(struct rdma_cm_id *cm_id)
 874 {
 875         struct nvmet_port *port = cm_id->context;
 876         struct nvmet_rdma_device *ndev;
 877         int inline_page_count;
 878         int inline_sge_count;
 879         int ret;
 880
 881         mutex_lock(&device_list_mutex);
 882         list_for_each_entry(ndev, &device_list, entry) {
 883                 if (ndev->device->node_guid == cm_id->device->node_guid &&
 884                     kref_get_unless_zero(&ndev->ref))
 885                         goto out_unlock;
 886         }
 887
 888         ndev = kzalloc(sizeof(*ndev), GFP_KERNEL);
 889         if (!ndev)
 890                 goto out_err;
 891
 892         inline_page_count = num_pages(port->inline_data_size);
 893         inline_sge_count = max(cm_id->device->attrs.max_sge_rd,
 894                                 cm_id->device->attrs.max_recv_sge) - 1;
 895         if (inline_page_count > inline_sge_count) {
 896                 pr_warn("inline_data_size %d cannot be supported by device %s. Reducing to %lu.\n",
 897                         port->inline_data_size, cm_id->device->name,
 898                         inline_sge_count * PAGE_SIZE);
 899                 port->inline_data_size = inline_sge_count * PAGE_SIZE;
 900                 inline_page_count = inline_sge_count;
 901         }
 902         ndev->inline_data_size = port->inline_data_size;
 903         ndev->inline_page_count = inline_page_count;
 904         ndev->device = cm_id->device;
 905         kref_init(&ndev->ref);
 906
 907         ndev->pd = ib_alloc_pd(ndev->device, 0);
 908         if (IS_ERR(ndev->pd))
 909                 goto out_free_dev;
 910
 911         if (nvmet_rdma_use_srq) {
 912                 ret = nvmet_rdma_init_srq(ndev);
 913                 if (ret)
 914                         goto out_free_pd;
 915         }
 916
 917         list_add(&ndev->entry, &device_list);
 918 out_unlock:
 919         mutex_unlock(&device_list_mutex);
 920         pr_debug("added %s.\n", ndev->device->name);
 921         return ndev;
 922
 923 out_free_pd:
 924         ib_dealloc_pd(ndev->pd);
 925 out_free_dev:
 926         kfree(ndev);
 927 out_err:
 928         mutex_unlock(&device_list_mutex);
 929         return NULL;
 930 }
 931
 932 static int nvmet_rdma_create_queue_ib(struct nvmet_rdma_queue *queue)
 933 {
 934         struct ib_qp_init_attr qp_attr;
 935         struct nvmet_rdma_device *ndev = queue->dev;
 936         int comp_vector, nr_cqe, ret, i;
 937
 938         /*
 939          * Spread the io queues across completion vectors,
 940          * but still keep all admin queues on vector 0.
 941          */
 942         comp_vector = !queue->host_qid ? 0 :
 943                 queue->idx % ndev->device->num_comp_vectors;
 944
 945         /*
 946          * Reserve CQ slots for RECV + RDMA_READ/RDMA_WRITE + RDMA_SEND.
 947          */
 948         nr_cqe = queue->recv_queue_size + 2 * queue->send_queue_size;
 949
 950         queue->cq = ib_alloc_cq(ndev->device, queue,
 951                         nr_cqe + 1, comp_vector,
 952                         IB_POLL_WORKQUEUE);
 953         if (IS_ERR(queue->cq)) {
 954                 ret = PTR_ERR(queue->cq);
 955                 pr_err("failed to create CQ cqe= %d ret= %d\n",
 956                        nr_cqe + 1, ret);
 957                 goto out;
 958         }
 959
 960         memset(&qp_attr, 0, sizeof(qp_attr));
 961         qp_attr.qp_context = queue;
 962         qp_attr.event_handler = nvmet_rdma_qp_event;
 963         qp_attr.send_cq = queue->cq;
 964         qp_attr.recv_cq = queue->cq;
 965         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
 966         qp_attr.qp_type = IB_QPT_RC;
 967         /* +1 for drain */
 968         qp_attr.cap.max_send_wr = queue->send_queue_size + 1;
 969         qp_attr.cap.max_rdma_ctxs = queue->send_queue_size;
 970         qp_attr.cap.max_send_sge = max(ndev->device->attrs.max_sge_rd,
 971                                         ndev->device->attrs.max_send_sge);
 972
 973         if (ndev->srq) {
 974                 qp_attr.srq = ndev->srq;
 975         } else {
 976                 /* +1 for drain */
 977                 qp_attr.cap.max_recv_wr = 1 + queue->recv_queue_size;
 978                 qp_attr.cap.max_recv_sge = 1 + ndev->inline_page_count;
 979         }
 980
 981         ret = rdma_create_qp(queue->cm_id, ndev->pd, &qp_attr);
 982         if (ret) {
 983                 pr_err("failed to create_qp ret= %d\n", ret);
 984                 goto err_destroy_cq;
 985         }
 986
 987         atomic_set(&queue->sq_wr_avail, qp_attr.cap.max_send_wr);
 988
 989         pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
 990                  __func__, queue->cq->cqe, qp_attr.cap.max_send_sge,
 991                  qp_attr.cap.max_send_wr, queue->cm_id);
 992
 993         if (!ndev->srq) {
 994                 for (i = 0; i < queue->recv_queue_size; i++) {
 995                         queue->cmds[i].queue = queue;
 996                         ret = nvmet_rdma_post_recv(ndev, &queue->cmds[i]);
 997                         if (ret)
 998                                 goto err_destroy_qp;
 999                 }
1000         }
1001
1002 out:
1003         return ret;
1004
1005 err_destroy_qp:
1006         rdma_destroy_qp(queue->cm_id);
1007 err_destroy_cq:
1008         ib_free_cq(queue->cq);
1009         goto out;
1010 }
1011
1012 static void nvmet_rdma_destroy_queue_ib(struct nvmet_rdma_queue *queue)
1013 {
1014         struct ib_qp *qp = queue->cm_id->qp;
1015
1016         ib_drain_qp(qp);
1017         rdma_destroy_id(queue->cm_id);
1018         ib_destroy_qp(qp);
1019         ib_free_cq(queue->cq);
1020 }
1021
1022 static void nvmet_rdma_free_queue(struct nvmet_rdma_queue *queue)
1023 {
1024         pr_debug("freeing queue %d\n", queue->idx);
1025
1026         nvmet_sq_destroy(&queue->nvme_sq);
1027
1028         nvmet_rdma_destroy_queue_ib(queue);
1029         if (!queue->dev->srq) {
1030                 nvmet_rdma_free_cmds(queue->dev, queue->cmds,
1031                                 queue->recv_queue_size,
1032                                 !queue->host_qid);
1033         }
1034         nvmet_rdma_free_rsps(queue);
1035         ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
1036         kfree(queue);
1037 }
1038
1039 static void nvmet_rdma_release_queue_work(struct work_struct *w)
1040 {
1041         struct nvmet_rdma_queue *queue =
1042                 container_of(w, struct nvmet_rdma_queue, release_work);
1043         struct nvmet_rdma_device *dev = queue->dev;
1044
1045         nvmet_rdma_free_queue(queue);
1046
1047         kref_put(&dev->ref, nvmet_rdma_free_dev);
1048 }
1049
1050 static int
1051 nvmet_rdma_parse_cm_connect_req(struct rdma_conn_param *conn,
1052                                 struct nvmet_rdma_queue *queue)
1053 {
1054         struct nvme_rdma_cm_req *req;
1055
1056         req = (struct nvme_rdma_cm_req *)conn->private_data;
1057         if (!req || conn->private_data_len == 0)
1058                 return NVME_RDMA_CM_INVALID_LEN;
1059
1060         if (le16_to_cpu(req->recfmt) != NVME_RDMA_CM_FMT_1_0)
1061                 return NVME_RDMA_CM_INVALID_RECFMT;
1062
1063         queue->host_qid = le16_to_cpu(req->qid);
1064
1065         /*
1066          * req->hsqsize corresponds to our recv queue size plus 1
1067          * req->hrqsize corresponds to our send queue size
1068          */
1069         queue->recv_queue_size = le16_to_cpu(req->hsqsize) + 1;
1070         queue->send_queue_size = le16_to_cpu(req->hrqsize);
1071
1072         if (!queue->host_qid && queue->recv_queue_size > NVME_AQ_DEPTH)
1073                 return NVME_RDMA_CM_INVALID_HSQSIZE;
1074
1075         /* XXX: Should we enforce some kind of max for IO queues? */
1076
1077         return 0;
1078 }
1079
1080 static int nvmet_rdma_cm_reject(struct rdma_cm_id *cm_id,
1081                                 enum nvme_rdma_cm_status status)
1082 {
1083         struct nvme_rdma_cm_rej rej;
1084
1085         pr_debug("rejecting connect request: status %d (%s)\n",
1086                  status, nvme_rdma_cm_msg(status));
1087
1088         rej.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
1089         rej.sts = cpu_to_le16(status);
1090
1091         return rdma_reject(cm_id, (void *)&rej, sizeof(rej));
1092 }
1093
1094 static struct nvmet_rdma_queue *
1095 nvmet_rdma_alloc_queue(struct nvmet_rdma_device *ndev,
1096                 struct rdma_cm_id *cm_id,
1097                 struct rdma_cm_event *event)
1098 {
1099         struct nvmet_rdma_queue *queue;
1100         int ret;
1101
1102         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1103         if (!queue) {
1104                 ret = NVME_RDMA_CM_NO_RSC;
1105                 goto out_reject;
1106         }
1107
1108         ret = nvmet_sq_init(&queue->nvme_sq);
1109         if (ret) {
1110                 ret = NVME_RDMA_CM_NO_RSC;
1111                 goto out_free_queue;
1112         }
1113
1114         ret = nvmet_rdma_parse_cm_connect_req(&event->param.conn, queue);
1115         if (ret)
1116                 goto out_destroy_sq;
1117
1118         /*
1119          * Schedules the actual release because calling rdma_destroy_id from
1120          * inside a CM callback would trigger a deadlock. (great API design..)
1121          */
1122         INIT_WORK(&queue->release_work, nvmet_rdma_release_queue_work);
1123         queue->dev = ndev;
1124         queue->cm_id = cm_id;
1125
1126         spin_lock_init(&queue->state_lock);
1127         queue->state = NVMET_RDMA_Q_CONNECTING;
1128         INIT_LIST_HEAD(&queue->rsp_wait_list);
1129         INIT_LIST_HEAD(&queue->rsp_wr_wait_list);
1130         spin_lock_init(&queue->rsp_wr_wait_lock);
1131         INIT_LIST_HEAD(&queue->free_rsps);
1132         spin_lock_init(&queue->rsps_lock);
1133         INIT_LIST_HEAD(&queue->queue_list);
1134
1135         queue->idx = ida_simple_get(&nvmet_rdma_queue_ida, 0, 0, GFP_KERNEL);
1136         if (queue->idx < 0) {
1137                 ret = NVME_RDMA_CM_NO_RSC;
1138                 goto out_destroy_sq;
1139         }
1140
1141         ret = nvmet_rdma_alloc_rsps(queue);
1142         if (ret) {
1143                 ret = NVME_RDMA_CM_NO_RSC;
1144                 goto out_ida_remove;
1145         }
1146
1147         if (!ndev->srq) {
1148                 queue->cmds = nvmet_rdma_alloc_cmds(ndev,
1149                                 queue->recv_queue_size,
1150                                 !queue->host_qid);
1151                 if (IS_ERR(queue->cmds)) {
1152                         ret = NVME_RDMA_CM_NO_RSC;
1153                         goto out_free_responses;
1154                 }
1155         }
1156
1157         ret = nvmet_rdma_create_queue_ib(queue);
1158         if (ret) {
1159                 pr_err("%s: creating RDMA queue failed (%d).\n",
1160                         __func__, ret);
1161                 ret = NVME_RDMA_CM_NO_RSC;
1162                 goto out_free_cmds;
1163         }
1164
1165         return queue;
1166
1167 out_free_cmds:
1168         if (!ndev->srq) {
1169                 nvmet_rdma_free_cmds(queue->dev, queue->cmds,
1170                                 queue->recv_queue_size,
1171                                 !queue->host_qid);
1172         }
1173 out_free_responses:
1174         nvmet_rdma_free_rsps(queue);
1175 out_ida_remove:
1176         ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
1177 out_destroy_sq:
1178         nvmet_sq_destroy(&queue->nvme_sq);
1179 out_free_queue:
1180         kfree(queue);
1181 out_reject:
1182         nvmet_rdma_cm_reject(cm_id, ret);
1183         return NULL;
1184 }
1185
1186 static void nvmet_rdma_qp_event(struct ib_event *event, void *priv)
1187 {
1188         struct nvmet_rdma_queue *queue = priv;
1189
1190         switch (event->event) {
1191         case IB_EVENT_COMM_EST:
1192                 rdma_notify(queue->cm_id, event->event);
1193                 break;
1194         default:
1195                 pr_err("received IB QP event: %s (%d)\n",
1196                        ib_event_msg(event->event), event->event);
1197                 break;
1198         }
1199 }
1200
1201 static int nvmet_rdma_cm_accept(struct rdma_cm_id *cm_id,
1202                 struct nvmet_rdma_queue *queue,
1203                 struct rdma_conn_param *p)
1204 {
1205         struct rdma_conn_param  param = { };
1206         struct nvme_rdma_cm_rep priv = { };
1207         int ret = -ENOMEM;
1208
1209         param.rnr_retry_count = 7;
1210         param.flow_control = 1;
1211         param.initiator_depth = min_t(u8, p->initiator_depth,
1212                 queue->dev->device->attrs.max_qp_init_rd_atom);
1213         param.private_data = &priv;
1214         param.private_data_len = sizeof(priv);
1215         priv.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
1216         priv.crqsize = cpu_to_le16(queue->recv_queue_size);
1217
1218         ret = rdma_accept(cm_id, &param);
1219         if (ret)
1220                 pr_err("rdma_accept failed (error code = %d)\n", ret);
1221
1222         return ret;
1223 }
1224
1225 static int nvmet_rdma_queue_connect(struct rdma_cm_id *cm_id,
1226                 struct rdma_cm_event *event)
1227 {
1228         struct nvmet_rdma_device *ndev;
1229         struct nvmet_rdma_queue *queue;
1230         int ret = -EINVAL;
1231
1232         ndev = nvmet_rdma_find_get_device(cm_id);
1233         if (!ndev) {
1234                 nvmet_rdma_cm_reject(cm_id, NVME_RDMA_CM_NO_RSC);
1235                 return -ECONNREFUSED;
1236         }
1237
1238         queue = nvmet_rdma_alloc_queue(ndev, cm_id, event);
1239         if (!queue) {
1240                 ret = -ENOMEM;
1241                 goto put_device;
1242         }
1243         queue->port = cm_id->context;
1244
1245         if (queue->host_qid == 0) {
1246                 /* Let inflight controller teardown complete */
1247                 flush_scheduled_work();
1248         }
1249
1250         ret = nvmet_rdma_cm_accept(cm_id, queue, &event->param.conn);
1251         if (ret) {
1252                 schedule_work(&queue->release_work);
1253                 /* Destroying rdma_cm id is not needed here */
1254                 return 0;
1255         }
1256
1257         mutex_lock(&nvmet_rdma_queue_mutex);
1258         list_add_tail(&queue->queue_list, &nvmet_rdma_queue_list);
1259         mutex_unlock(&nvmet_rdma_queue_mutex);
1260
1261         return 0;
1262
1263 put_device:
1264         kref_put(&ndev->ref, nvmet_rdma_free_dev);
1265
1266         return ret;
1267 }
1268
1269 static void nvmet_rdma_queue_established(struct nvmet_rdma_queue *queue)
1270 {
1271         unsigned long flags;
1272
1273         spin_lock_irqsave(&queue->state_lock, flags);
1274         if (queue->state != NVMET_RDMA_Q_CONNECTING) {
1275                 pr_warn("trying to establish a connected queue\n");
1276                 goto out_unlock;
1277         }
1278         queue->state = NVMET_RDMA_Q_LIVE;
1279
1280         while (!list_empty(&queue->rsp_wait_list)) {
1281                 struct nvmet_rdma_rsp *cmd;
1282
1283                 cmd = list_first_entry(&queue->rsp_wait_list,
1284                                         struct nvmet_rdma_rsp, wait_list);
1285                 list_del(&cmd->wait_list);
1286
1287                 spin_unlock_irqrestore(&queue->state_lock, flags);
1288                 nvmet_rdma_handle_command(queue, cmd);
1289                 spin_lock_irqsave(&queue->state_lock, flags);
1290         }
1291
1292 out_unlock:
1293         spin_unlock_irqrestore(&queue->state_lock, flags);
1294 }
1295
1296 static void __nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
1297 {
1298         bool disconnect = false;
1299         unsigned long flags;
1300
1301         pr_debug("cm_id= %p queue->state= %d\n", queue->cm_id, queue->state);
1302
1303         spin_lock_irqsave(&queue->state_lock, flags);
1304         switch (queue->state) {
1305         case NVMET_RDMA_Q_CONNECTING:
1306         case NVMET_RDMA_Q_LIVE:
1307                 queue->state = NVMET_RDMA_Q_DISCONNECTING;
1308                 disconnect = true;
1309                 break;
1310         case NVMET_RDMA_Q_DISCONNECTING:
1311                 break;
1312         }
1313         spin_unlock_irqrestore(&queue->state_lock, flags);
1314
1315         if (disconnect) {
1316                 rdma_disconnect(queue->cm_id);
1317                 schedule_work(&queue->release_work);
1318         }
1319 }
1320
1321 static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
1322 {
1323         bool disconnect = false;
1324
1325         mutex_lock(&nvmet_rdma_queue_mutex);
1326         if (!list_empty(&queue->queue_list)) {
1327                 list_del_init(&queue->queue_list);
1328                 disconnect = true;
1329         }
1330         mutex_unlock(&nvmet_rdma_queue_mutex);
1331
1332         if (disconnect)
1333                 __nvmet_rdma_queue_disconnect(queue);
1334 }
1335
1336 static void nvmet_rdma_queue_connect_fail(struct rdma_cm_id *cm_id,
1337                 struct nvmet_rdma_queue *queue)
1338 {
1339         WARN_ON_ONCE(queue->state != NVMET_RDMA_Q_CONNECTING);
1340
1341         mutex_lock(&nvmet_rdma_queue_mutex);
1342         if (!list_empty(&queue->queue_list))
1343                 list_del_init(&queue->queue_list);
1344         mutex_unlock(&nvmet_rdma_queue_mutex);
1345
1346         pr_err("failed to connect queue %d\n", queue->idx);
1347         schedule_work(&queue->release_work);
1348 }
1349
1350 /**
1351  * nvme_rdma_device_removal() - Handle RDMA device removal
1352  * @cm_id:      rdma_cm id, used for nvmet port
1353  * @queue:      nvmet rdma queue (cm id qp_context)
1354  *
1355  * DEVICE_REMOVAL event notifies us that the RDMA device is about
1356  * to unplug. Note that this event can be generated on a normal
1357  * queue cm_id and/or a device bound listener cm_id (where in this
1358  * case queue will be null).
1359  *
1360  * We registered an ib_client to handle device removal for queues,
1361  * so we only need to handle the listening port cm_ids. In this case
1362  * we nullify the priv to prevent double cm_id destruction and destroying
1363  * the cm_id implicitely by returning a non-zero rc to the callout.
1364  */
1365 static int nvmet_rdma_device_removal(struct rdma_cm_id *cm_id,
1366                 struct nvmet_rdma_queue *queue)
1367 {
1368         struct nvmet_port *port;
1369
1370         if (queue) {
1371                 /*
1372                  * This is a queue cm_id. we have registered
1373                  * an ib_client to handle queues removal
1374                  * so don't interfear and just return.
1375                  */
1376                 return 0;
1377         }
1378
1379         port = cm_id->context;
1380
1381         /*
1382          * This is a listener cm_id. Make sure that
1383          * future remove_port won't invoke a double
1384          * cm_id destroy. use atomic xchg to make sure
1385          * we don't compete with remove_port.
1386          */
1387         if (xchg(&port->priv, NULL) != cm_id)
1388                 return 0;
1389
1390         /*
1391          * We need to return 1 so that the core will destroy
1392          * it's own ID.  What a great API design..
1393          */
1394         return 1;
1395 }
1396
1397 static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
1398                 struct rdma_cm_event *event)
1399 {
1400         struct nvmet_rdma_queue *queue = NULL;
1401         int ret = 0;
1402
1403         if (cm_id->qp)
1404                 queue = cm_id->qp->qp_context;
1405
1406         pr_debug("%s (%d): status %d id %p\n",
1407                 rdma_event_msg(event->event), event->event,
1408                 event->status, cm_id);
1409
1410         switch (event->event) {
1411         case RDMA_CM_EVENT_CONNECT_REQUEST:
1412                 ret = nvmet_rdma_queue_connect(cm_id, event);
1413                 break;
1414         case RDMA_CM_EVENT_ESTABLISHED:
1415                 nvmet_rdma_queue_established(queue);
1416                 break;
1417         case RDMA_CM_EVENT_ADDR_CHANGE:
1418         case RDMA_CM_EVENT_DISCONNECTED:
1419         case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1420                 nvmet_rdma_queue_disconnect(queue);
1421                 break;
1422         case RDMA_CM_EVENT_DEVICE_REMOVAL:
1423                 ret = nvmet_rdma_device_removal(cm_id, queue);
1424                 break;
1425         case RDMA_CM_EVENT_REJECTED:
1426                 pr_debug("Connection rejected: %s\n",
1427                          rdma_reject_msg(cm_id, event->status));
1428                 /* FALLTHROUGH */
1429         case RDMA_CM_EVENT_UNREACHABLE:
1430         case RDMA_CM_EVENT_CONNECT_ERROR:
1431                 nvmet_rdma_queue_connect_fail(cm_id, queue);
1432                 break;
1433         default:
1434                 pr_err("received unrecognized RDMA CM event %d\n",
1435                         event->event);
1436                 break;
1437         }
1438
1439         return ret;
1440 }
1441
1442 static void nvmet_rdma_delete_ctrl(struct nvmet_ctrl *ctrl)
1443 {
1444         struct nvmet_rdma_queue *queue;
1445
1446 restart:
1447         mutex_lock(&nvmet_rdma_queue_mutex);
1448         list_for_each_entry(queue, &nvmet_rdma_queue_list, queue_list) {
1449                 if (queue->nvme_sq.ctrl == ctrl) {
1450                         list_del_init(&queue->queue_list);
1451                         mutex_unlock(&nvmet_rdma_queue_mutex);
1452
1453                         __nvmet_rdma_queue_disconnect(queue);
1454                         goto restart;
1455                 }
1456         }
1457         mutex_unlock(&nvmet_rdma_queue_mutex);
1458 }
1459
1460 static int nvmet_rdma_add_port(struct nvmet_port *port)
1461 {
1462         struct rdma_cm_id *cm_id;
1463         struct sockaddr_storage addr = { };
1464         __kernel_sa_family_t af;
1465         int ret;
1466
1467         switch (port->disc_addr.adrfam) {
1468         case NVMF_ADDR_FAMILY_IP4:
1469                 af = AF_INET;
1470                 break;
1471         case NVMF_ADDR_FAMILY_IP6:
1472                 af = AF_INET6;
1473                 break;
1474         default:
1475                 pr_err("address family %d not supported\n",
1476                                 port->disc_addr.adrfam);
1477                 return -EINVAL;
1478         }
1479
1480         if (port->inline_data_size < 0) {
1481                 port->inline_data_size = NVMET_RDMA_DEFAULT_INLINE_DATA_SIZE;
1482         } else if (port->inline_data_size > NVMET_RDMA_MAX_INLINE_DATA_SIZE) {
1483                 pr_warn("inline_data_size %u is too large, reducing to %u\n",
1484                         port->inline_data_size,
1485                         NVMET_RDMA_MAX_INLINE_DATA_SIZE);
1486                 port->inline_data_size = NVMET_RDMA_MAX_INLINE_DATA_SIZE;
1487         }
1488
1489         ret = inet_pton_with_scope(&init_net, af, port->disc_addr.traddr,
1490                         port->disc_addr.trsvcid, &addr);
1491         if (ret) {
1492                 pr_err("malformed ip/port passed: %s:%s\n",
1493                         port->disc_addr.traddr, port->disc_addr.trsvcid);
1494                 return ret;
1495         }
1496
1497         cm_id = rdma_create_id(&init_net, nvmet_rdma_cm_handler, port,
1498                         RDMA_PS_TCP, IB_QPT_RC);
1499         if (IS_ERR(cm_id)) {
1500                 pr_err("CM ID creation failed\n");
1501                 return PTR_ERR(cm_id);
1502         }
1503
1504         /*
1505          * Allow both IPv4 and IPv6 sockets to bind a single port
1506          * at the same time.
1507          */
1508         ret = rdma_set_afonly(cm_id, 1);
1509         if (ret) {
1510                 pr_err("rdma_set_afonly failed (%d)\n", ret);
1511                 goto out_destroy_id;
1512         }
1513
1514         ret = rdma_bind_addr(cm_id, (struct sockaddr *)&addr);
1515         if (ret) {
1516                 pr_err("binding CM ID to %pISpcs failed (%d)\n",
1517                         (struct sockaddr *)&addr, ret);
1518                 goto out_destroy_id;
1519         }
1520
1521         ret = rdma_listen(cm_id, 128);
1522         if (ret) {
1523                 pr_err("listening to %pISpcs failed (%d)\n",
1524                         (struct sockaddr *)&addr, ret);
1525                 goto out_destroy_id;
1526         }
1527
1528         pr_info("enabling port %d (%pISpcs)\n",
1529                 le16_to_cpu(port->disc_addr.portid), (struct sockaddr *)&addr);
1530         port->priv = cm_id;
1531         return 0;
1532
1533 out_destroy_id:
1534         rdma_destroy_id(cm_id);
1535         return ret;
1536 }
1537
1538 static void nvmet_rdma_remove_port(struct nvmet_port *port)
1539 {
1540         struct rdma_cm_id *cm_id = xchg(&port->priv, NULL);
1541
1542         if (cm_id)
1543                 rdma_destroy_id(cm_id);
1544 }
1545
1546 static void nvmet_rdma_disc_port_addr(struct nvmet_req *req,
1547                 struct nvmet_port *port, char *traddr)
1548 {
1549         struct rdma_cm_id *cm_id = port->priv;
1550
1551         if (inet_addr_is_any((struct sockaddr *)&cm_id->route.addr.src_addr)) {
1552                 struct nvmet_rdma_rsp *rsp =
1553                         container_of(req, struct nvmet_rdma_rsp, req);
1554                 struct rdma_cm_id *req_cm_id = rsp->queue->cm_id;
1555                 struct sockaddr *addr = (void *)&req_cm_id->route.addr.src_addr;
1556
1557                 sprintf(traddr, "%pISc", addr);
1558         } else {
1559                 memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
1560         }
1561 }
1562
1563 static const struct nvmet_fabrics_ops nvmet_rdma_ops = {
1564         .owner                  = THIS_MODULE,
1565         .type                   = NVMF_TRTYPE_RDMA,
1566         .msdbd                  = 1,
1567         .has_keyed_sgls         = 1,
1568         .add_port               = nvmet_rdma_add_port,
1569         .remove_port            = nvmet_rdma_remove_port,
1570         .queue_response         = nvmet_rdma_queue_response,
1571         .delete_ctrl            = nvmet_rdma_delete_ctrl,
1572         .disc_traddr            = nvmet_rdma_disc_port_addr,
1573 };
1574
1575 static void nvmet_rdma_remove_one(struct ib_device *ib_device, void *client_data)
1576 {
1577         struct nvmet_rdma_queue *queue, *tmp;
1578         struct nvmet_rdma_device *ndev;
1579         bool found = false;
1580
1581         mutex_lock(&device_list_mutex);
1582         list_for_each_entry(ndev, &device_list, entry) {
1583                 if (ndev->device == ib_device) {
1584                         found = true;
1585                         break;
1586                 }
1587         }
1588         mutex_unlock(&device_list_mutex);
1589
1590         if (!found)
1591                 return;
1592
1593         /*
1594          * IB Device that is used by nvmet controllers is being removed,
1595          * delete all queues using this device.
1596          */
1597         mutex_lock(&nvmet_rdma_queue_mutex);
1598         list_for_each_entry_safe(queue, tmp, &nvmet_rdma_queue_list,
1599                                  queue_list) {
1600                 if (queue->dev->device != ib_device)
1601                         continue;
1602
1603                 pr_info("Removing queue %d\n", queue->idx);
1604                 list_del_init(&queue->queue_list);
1605                 __nvmet_rdma_queue_disconnect(queue);
1606         }
1607         mutex_unlock(&nvmet_rdma_queue_mutex);
1608
1609         flush_scheduled_work();
1610 }
1611
1612 static struct ib_client nvmet_rdma_ib_client = {
1613         .name   = "nvmet_rdma",
1614         .remove = nvmet_rdma_remove_one
1615 };
1616
1617 static int __init nvmet_rdma_init(void)
1618 {
1619         int ret;
1620
1621         ret = ib_register_client(&nvmet_rdma_ib_client);
1622         if (ret)
1623                 return ret;
1624
1625         ret = nvmet_register_transport(&nvmet_rdma_ops);
1626         if (ret)
1627                 goto err_ib_client;
1628
1629         return 0;
1630
1631 err_ib_client:
1632         ib_unregister_client(&nvmet_rdma_ib_client);
1633         return ret;
1634 }
1635
1636 static void __exit nvmet_rdma_exit(void)
1637 {
1638         nvmet_unregister_transport(&nvmet_rdma_ops);
1639         ib_unregister_client(&nvmet_rdma_ib_client);
1640         WARN_ON_ONCE(!list_empty(&nvmet_rdma_queue_list));
1641         ida_destroy(&nvmet_rdma_queue_ida);
1642 }
1643
1644 module_init(nvmet_rdma_init);
1645 module_exit(nvmet_rdma_exit);
1646
1647 MODULE_LICENSE("GPL v2");
1648 MODULE_ALIAS("nvmet-transport-1"); /* 1 == NVMF_TRTYPE_RDMA */