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TOMOYO Linux Cross Reference
Linux/net/sunrpc/xprtrdma/svc_rdma_transport.c

Version: ~ [ linux-5.4.2 ] ~ [ linux-5.3.15 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.88 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.158 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.206 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.206 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.78 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * Copyright (c) 2014 Open Grid Computing, Inc. All rights reserved.
  3  * Copyright (c) 2005-2007 Network Appliance, Inc. All rights reserved.
  4  *
  5  * This software is available to you under a choice of one of two
  6  * licenses.  You may choose to be licensed under the terms of the GNU
  7  * General Public License (GPL) Version 2, available from the file
  8  * COPYING in the main directory of this source tree, or the BSD-type
  9  * license below:
 10  *
 11  * Redistribution and use in source and binary forms, with or without
 12  * modification, are permitted provided that the following conditions
 13  * are met:
 14  *
 15  *      Redistributions of source code must retain the above copyright
 16  *      notice, this list of conditions and the following 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 provided
 21  *      with the distribution.
 22  *
 23  *      Neither the name of the Network Appliance, Inc. nor the names of
 24  *      its contributors may be used to endorse or promote products
 25  *      derived from this software without specific prior written
 26  *      permission.
 27  *
 28  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 29  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 30  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 31  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 32  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 33  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 34  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 35  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 36  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 37  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 38  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 39  *
 40  * Author: Tom Tucker <tom@opengridcomputing.com>
 41  */
 42 
 43 #include <linux/sunrpc/svc_xprt.h>
 44 #include <linux/sunrpc/debug.h>
 45 #include <linux/sunrpc/rpc_rdma.h>
 46 #include <linux/interrupt.h>
 47 #include <linux/sched.h>
 48 #include <linux/slab.h>
 49 #include <linux/spinlock.h>
 50 #include <linux/workqueue.h>
 51 #include <rdma/ib_verbs.h>
 52 #include <rdma/rdma_cm.h>
 53 #include <linux/sunrpc/svc_rdma.h>
 54 #include <linux/export.h>
 55 #include "xprt_rdma.h"
 56 
 57 #define RPCDBG_FACILITY RPCDBG_SVCXPRT
 58 
 59 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
 60                                         struct net *net,
 61                                         struct sockaddr *sa, int salen,
 62                                         int flags);
 63 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt);
 64 static void svc_rdma_release_rqst(struct svc_rqst *);
 65 static void dto_tasklet_func(unsigned long data);
 66 static void svc_rdma_detach(struct svc_xprt *xprt);
 67 static void svc_rdma_free(struct svc_xprt *xprt);
 68 static int svc_rdma_has_wspace(struct svc_xprt *xprt);
 69 static int svc_rdma_secure_port(struct svc_rqst *);
 70 static void rq_cq_reap(struct svcxprt_rdma *xprt);
 71 static void sq_cq_reap(struct svcxprt_rdma *xprt);
 72 
 73 static DECLARE_TASKLET(dto_tasklet, dto_tasklet_func, 0UL);
 74 static DEFINE_SPINLOCK(dto_lock);
 75 static LIST_HEAD(dto_xprt_q);
 76 
 77 static struct svc_xprt_ops svc_rdma_ops = {
 78         .xpo_create = svc_rdma_create,
 79         .xpo_recvfrom = svc_rdma_recvfrom,
 80         .xpo_sendto = svc_rdma_sendto,
 81         .xpo_release_rqst = svc_rdma_release_rqst,
 82         .xpo_detach = svc_rdma_detach,
 83         .xpo_free = svc_rdma_free,
 84         .xpo_prep_reply_hdr = svc_rdma_prep_reply_hdr,
 85         .xpo_has_wspace = svc_rdma_has_wspace,
 86         .xpo_accept = svc_rdma_accept,
 87         .xpo_secure_port = svc_rdma_secure_port,
 88 };
 89 
 90 struct svc_xprt_class svc_rdma_class = {
 91         .xcl_name = "rdma",
 92         .xcl_owner = THIS_MODULE,
 93         .xcl_ops = &svc_rdma_ops,
 94         .xcl_max_payload = RPCSVC_MAXPAYLOAD_RDMA,
 95         .xcl_ident = XPRT_TRANSPORT_RDMA,
 96 };
 97 
 98 struct svc_rdma_op_ctxt *svc_rdma_get_context(struct svcxprt_rdma *xprt)
 99 {
100         struct svc_rdma_op_ctxt *ctxt;
101 
102         ctxt = kmem_cache_alloc(svc_rdma_ctxt_cachep,
103                                 GFP_KERNEL | __GFP_NOFAIL);
104         ctxt->xprt = xprt;
105         INIT_LIST_HEAD(&ctxt->dto_q);
106         ctxt->count = 0;
107         ctxt->frmr = NULL;
108         atomic_inc(&xprt->sc_ctxt_used);
109         return ctxt;
110 }
111 
112 void svc_rdma_unmap_dma(struct svc_rdma_op_ctxt *ctxt)
113 {
114         struct svcxprt_rdma *xprt = ctxt->xprt;
115         int i;
116         for (i = 0; i < ctxt->count && ctxt->sge[i].length; i++) {
117                 /*
118                  * Unmap the DMA addr in the SGE if the lkey matches
119                  * the sc_dma_lkey, otherwise, ignore it since it is
120                  * an FRMR lkey and will be unmapped later when the
121                  * last WR that uses it completes.
122                  */
123                 if (ctxt->sge[i].lkey == xprt->sc_dma_lkey) {
124                         atomic_dec(&xprt->sc_dma_used);
125                         ib_dma_unmap_page(xprt->sc_cm_id->device,
126                                             ctxt->sge[i].addr,
127                                             ctxt->sge[i].length,
128                                             ctxt->direction);
129                 }
130         }
131 }
132 
133 void svc_rdma_put_context(struct svc_rdma_op_ctxt *ctxt, int free_pages)
134 {
135         struct svcxprt_rdma *xprt;
136         int i;
137 
138         xprt = ctxt->xprt;
139         if (free_pages)
140                 for (i = 0; i < ctxt->count; i++)
141                         put_page(ctxt->pages[i]);
142 
143         kmem_cache_free(svc_rdma_ctxt_cachep, ctxt);
144         atomic_dec(&xprt->sc_ctxt_used);
145 }
146 
147 /*
148  * Temporary NFS req mappings are shared across all transport
149  * instances. These are short lived and should be bounded by the number
150  * of concurrent server threads * depth of the SQ.
151  */
152 struct svc_rdma_req_map *svc_rdma_get_req_map(void)
153 {
154         struct svc_rdma_req_map *map;
155         map = kmem_cache_alloc(svc_rdma_map_cachep,
156                                GFP_KERNEL | __GFP_NOFAIL);
157         map->count = 0;
158         return map;
159 }
160 
161 void svc_rdma_put_req_map(struct svc_rdma_req_map *map)
162 {
163         kmem_cache_free(svc_rdma_map_cachep, map);
164 }
165 
166 /* ib_cq event handler */
167 static void cq_event_handler(struct ib_event *event, void *context)
168 {
169         struct svc_xprt *xprt = context;
170         dprintk("svcrdma: received CQ event %s (%d), context=%p\n",
171                 ib_event_msg(event->event), event->event, context);
172         set_bit(XPT_CLOSE, &xprt->xpt_flags);
173 }
174 
175 /* QP event handler */
176 static void qp_event_handler(struct ib_event *event, void *context)
177 {
178         struct svc_xprt *xprt = context;
179 
180         switch (event->event) {
181         /* These are considered benign events */
182         case IB_EVENT_PATH_MIG:
183         case IB_EVENT_COMM_EST:
184         case IB_EVENT_SQ_DRAINED:
185         case IB_EVENT_QP_LAST_WQE_REACHED:
186                 dprintk("svcrdma: QP event %s (%d) received for QP=%p\n",
187                         ib_event_msg(event->event), event->event,
188                         event->element.qp);
189                 break;
190         /* These are considered fatal events */
191         case IB_EVENT_PATH_MIG_ERR:
192         case IB_EVENT_QP_FATAL:
193         case IB_EVENT_QP_REQ_ERR:
194         case IB_EVENT_QP_ACCESS_ERR:
195         case IB_EVENT_DEVICE_FATAL:
196         default:
197                 dprintk("svcrdma: QP ERROR event %s (%d) received for QP=%p, "
198                         "closing transport\n",
199                         ib_event_msg(event->event), event->event,
200                         event->element.qp);
201                 set_bit(XPT_CLOSE, &xprt->xpt_flags);
202                 break;
203         }
204 }
205 
206 /*
207  * Data Transfer Operation Tasklet
208  *
209  * Walks a list of transports with I/O pending, removing entries as
210  * they are added to the server's I/O pending list. Two bits indicate
211  * if SQ, RQ, or both have I/O pending. The dto_lock is an irqsave
212  * spinlock that serializes access to the transport list with the RQ
213  * and SQ interrupt handlers.
214  */
215 static void dto_tasklet_func(unsigned long data)
216 {
217         struct svcxprt_rdma *xprt;
218         unsigned long flags;
219 
220         spin_lock_irqsave(&dto_lock, flags);
221         while (!list_empty(&dto_xprt_q)) {
222                 xprt = list_entry(dto_xprt_q.next,
223                                   struct svcxprt_rdma, sc_dto_q);
224                 list_del_init(&xprt->sc_dto_q);
225                 spin_unlock_irqrestore(&dto_lock, flags);
226 
227                 rq_cq_reap(xprt);
228                 sq_cq_reap(xprt);
229 
230                 svc_xprt_put(&xprt->sc_xprt);
231                 spin_lock_irqsave(&dto_lock, flags);
232         }
233         spin_unlock_irqrestore(&dto_lock, flags);
234 }
235 
236 /*
237  * Receive Queue Completion Handler
238  *
239  * Since an RQ completion handler is called on interrupt context, we
240  * need to defer the handling of the I/O to a tasklet
241  */
242 static void rq_comp_handler(struct ib_cq *cq, void *cq_context)
243 {
244         struct svcxprt_rdma *xprt = cq_context;
245         unsigned long flags;
246 
247         /* Guard against unconditional flush call for destroyed QP */
248         if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0)
249                 return;
250 
251         /*
252          * Set the bit regardless of whether or not it's on the list
253          * because it may be on the list already due to an SQ
254          * completion.
255          */
256         set_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags);
257 
258         /*
259          * If this transport is not already on the DTO transport queue,
260          * add it
261          */
262         spin_lock_irqsave(&dto_lock, flags);
263         if (list_empty(&xprt->sc_dto_q)) {
264                 svc_xprt_get(&xprt->sc_xprt);
265                 list_add_tail(&xprt->sc_dto_q, &dto_xprt_q);
266         }
267         spin_unlock_irqrestore(&dto_lock, flags);
268 
269         /* Tasklet does all the work to avoid irqsave locks. */
270         tasklet_schedule(&dto_tasklet);
271 }
272 
273 /*
274  * rq_cq_reap - Process the RQ CQ.
275  *
276  * Take all completing WC off the CQE and enqueue the associated DTO
277  * context on the dto_q for the transport.
278  *
279  * Note that caller must hold a transport reference.
280  */
281 static void rq_cq_reap(struct svcxprt_rdma *xprt)
282 {
283         int ret;
284         struct ib_wc wc;
285         struct svc_rdma_op_ctxt *ctxt = NULL;
286 
287         if (!test_and_clear_bit(RDMAXPRT_RQ_PENDING, &xprt->sc_flags))
288                 return;
289 
290         ib_req_notify_cq(xprt->sc_rq_cq, IB_CQ_NEXT_COMP);
291         atomic_inc(&rdma_stat_rq_poll);
292 
293         while ((ret = ib_poll_cq(xprt->sc_rq_cq, 1, &wc)) > 0) {
294                 ctxt = (struct svc_rdma_op_ctxt *)(unsigned long)wc.wr_id;
295                 ctxt->wc_status = wc.status;
296                 ctxt->byte_len = wc.byte_len;
297                 svc_rdma_unmap_dma(ctxt);
298                 if (wc.status != IB_WC_SUCCESS) {
299                         /* Close the transport */
300                         dprintk("svcrdma: transport closing putting ctxt %p\n", ctxt);
301                         set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
302                         svc_rdma_put_context(ctxt, 1);
303                         svc_xprt_put(&xprt->sc_xprt);
304                         continue;
305                 }
306                 spin_lock_bh(&xprt->sc_rq_dto_lock);
307                 list_add_tail(&ctxt->dto_q, &xprt->sc_rq_dto_q);
308                 spin_unlock_bh(&xprt->sc_rq_dto_lock);
309                 svc_xprt_put(&xprt->sc_xprt);
310         }
311 
312         if (ctxt)
313                 atomic_inc(&rdma_stat_rq_prod);
314 
315         set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
316         /*
317          * If data arrived before established event,
318          * don't enqueue. This defers RPC I/O until the
319          * RDMA connection is complete.
320          */
321         if (!test_bit(RDMAXPRT_CONN_PENDING, &xprt->sc_flags))
322                 svc_xprt_enqueue(&xprt->sc_xprt);
323 }
324 
325 /*
326  * Process a completion context
327  */
328 static void process_context(struct svcxprt_rdma *xprt,
329                             struct svc_rdma_op_ctxt *ctxt)
330 {
331         svc_rdma_unmap_dma(ctxt);
332 
333         switch (ctxt->wr_op) {
334         case IB_WR_SEND:
335                 if (ctxt->frmr)
336                         pr_err("svcrdma: SEND: ctxt->frmr != NULL\n");
337                 svc_rdma_put_context(ctxt, 1);
338                 break;
339 
340         case IB_WR_RDMA_WRITE:
341                 if (ctxt->frmr)
342                         pr_err("svcrdma: WRITE: ctxt->frmr != NULL\n");
343                 svc_rdma_put_context(ctxt, 0);
344                 break;
345 
346         case IB_WR_RDMA_READ:
347         case IB_WR_RDMA_READ_WITH_INV:
348                 svc_rdma_put_frmr(xprt, ctxt->frmr);
349                 if (test_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags)) {
350                         struct svc_rdma_op_ctxt *read_hdr = ctxt->read_hdr;
351                         if (read_hdr) {
352                                 spin_lock_bh(&xprt->sc_rq_dto_lock);
353                                 set_bit(XPT_DATA, &xprt->sc_xprt.xpt_flags);
354                                 list_add_tail(&read_hdr->dto_q,
355                                               &xprt->sc_read_complete_q);
356                                 spin_unlock_bh(&xprt->sc_rq_dto_lock);
357                         } else {
358                                 pr_err("svcrdma: ctxt->read_hdr == NULL\n");
359                         }
360                         svc_xprt_enqueue(&xprt->sc_xprt);
361                 }
362                 svc_rdma_put_context(ctxt, 0);
363                 break;
364 
365         default:
366                 printk(KERN_ERR "svcrdma: unexpected completion type, "
367                        "opcode=%d\n",
368                        ctxt->wr_op);
369                 break;
370         }
371 }
372 
373 /*
374  * Send Queue Completion Handler - potentially called on interrupt context.
375  *
376  * Note that caller must hold a transport reference.
377  */
378 static void sq_cq_reap(struct svcxprt_rdma *xprt)
379 {
380         struct svc_rdma_op_ctxt *ctxt = NULL;
381         struct ib_wc wc_a[6];
382         struct ib_wc *wc;
383         struct ib_cq *cq = xprt->sc_sq_cq;
384         int ret;
385 
386         memset(wc_a, 0, sizeof(wc_a));
387 
388         if (!test_and_clear_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags))
389                 return;
390 
391         ib_req_notify_cq(xprt->sc_sq_cq, IB_CQ_NEXT_COMP);
392         atomic_inc(&rdma_stat_sq_poll);
393         while ((ret = ib_poll_cq(cq, ARRAY_SIZE(wc_a), wc_a)) > 0) {
394                 int i;
395 
396                 for (i = 0; i < ret; i++) {
397                         wc = &wc_a[i];
398                         if (wc->status != IB_WC_SUCCESS) {
399                                 dprintk("svcrdma: sq wc err status %s (%d)\n",
400                                         ib_wc_status_msg(wc->status),
401                                         wc->status);
402 
403                                 /* Close the transport */
404                                 set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
405                         }
406 
407                         /* Decrement used SQ WR count */
408                         atomic_dec(&xprt->sc_sq_count);
409                         wake_up(&xprt->sc_send_wait);
410 
411                         ctxt = (struct svc_rdma_op_ctxt *)
412                                 (unsigned long)wc->wr_id;
413                         if (ctxt)
414                                 process_context(xprt, ctxt);
415 
416                         svc_xprt_put(&xprt->sc_xprt);
417                 }
418         }
419 
420         if (ctxt)
421                 atomic_inc(&rdma_stat_sq_prod);
422 }
423 
424 static void sq_comp_handler(struct ib_cq *cq, void *cq_context)
425 {
426         struct svcxprt_rdma *xprt = cq_context;
427         unsigned long flags;
428 
429         /* Guard against unconditional flush call for destroyed QP */
430         if (atomic_read(&xprt->sc_xprt.xpt_ref.refcount)==0)
431                 return;
432 
433         /*
434          * Set the bit regardless of whether or not it's on the list
435          * because it may be on the list already due to an RQ
436          * completion.
437          */
438         set_bit(RDMAXPRT_SQ_PENDING, &xprt->sc_flags);
439 
440         /*
441          * If this transport is not already on the DTO transport queue,
442          * add it
443          */
444         spin_lock_irqsave(&dto_lock, flags);
445         if (list_empty(&xprt->sc_dto_q)) {
446                 svc_xprt_get(&xprt->sc_xprt);
447                 list_add_tail(&xprt->sc_dto_q, &dto_xprt_q);
448         }
449         spin_unlock_irqrestore(&dto_lock, flags);
450 
451         /* Tasklet does all the work to avoid irqsave locks. */
452         tasklet_schedule(&dto_tasklet);
453 }
454 
455 static struct svcxprt_rdma *rdma_create_xprt(struct svc_serv *serv,
456                                              int listener)
457 {
458         struct svcxprt_rdma *cma_xprt = kzalloc(sizeof *cma_xprt, GFP_KERNEL);
459 
460         if (!cma_xprt)
461                 return NULL;
462         svc_xprt_init(&init_net, &svc_rdma_class, &cma_xprt->sc_xprt, serv);
463         INIT_LIST_HEAD(&cma_xprt->sc_accept_q);
464         INIT_LIST_HEAD(&cma_xprt->sc_dto_q);
465         INIT_LIST_HEAD(&cma_xprt->sc_rq_dto_q);
466         INIT_LIST_HEAD(&cma_xprt->sc_read_complete_q);
467         INIT_LIST_HEAD(&cma_xprt->sc_frmr_q);
468         init_waitqueue_head(&cma_xprt->sc_send_wait);
469 
470         spin_lock_init(&cma_xprt->sc_lock);
471         spin_lock_init(&cma_xprt->sc_rq_dto_lock);
472         spin_lock_init(&cma_xprt->sc_frmr_q_lock);
473 
474         cma_xprt->sc_ord = svcrdma_ord;
475 
476         cma_xprt->sc_max_req_size = svcrdma_max_req_size;
477         cma_xprt->sc_max_requests = svcrdma_max_requests;
478         cma_xprt->sc_sq_depth = svcrdma_max_requests * RPCRDMA_SQ_DEPTH_MULT;
479         atomic_set(&cma_xprt->sc_sq_count, 0);
480         atomic_set(&cma_xprt->sc_ctxt_used, 0);
481 
482         if (listener)
483                 set_bit(XPT_LISTENER, &cma_xprt->sc_xprt.xpt_flags);
484 
485         return cma_xprt;
486 }
487 
488 int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
489 {
490         struct ib_recv_wr recv_wr, *bad_recv_wr;
491         struct svc_rdma_op_ctxt *ctxt;
492         struct page *page;
493         dma_addr_t pa;
494         int sge_no;
495         int buflen;
496         int ret;
497 
498         ctxt = svc_rdma_get_context(xprt);
499         buflen = 0;
500         ctxt->direction = DMA_FROM_DEVICE;
501         for (sge_no = 0; buflen < xprt->sc_max_req_size; sge_no++) {
502                 if (sge_no >= xprt->sc_max_sge) {
503                         pr_err("svcrdma: Too many sges (%d)\n", sge_no);
504                         goto err_put_ctxt;
505                 }
506                 page = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
507                 ctxt->pages[sge_no] = page;
508                 pa = ib_dma_map_page(xprt->sc_cm_id->device,
509                                      page, 0, PAGE_SIZE,
510                                      DMA_FROM_DEVICE);
511                 if (ib_dma_mapping_error(xprt->sc_cm_id->device, pa))
512                         goto err_put_ctxt;
513                 atomic_inc(&xprt->sc_dma_used);
514                 ctxt->sge[sge_no].addr = pa;
515                 ctxt->sge[sge_no].length = PAGE_SIZE;
516                 ctxt->sge[sge_no].lkey = xprt->sc_dma_lkey;
517                 ctxt->count = sge_no + 1;
518                 buflen += PAGE_SIZE;
519         }
520         recv_wr.next = NULL;
521         recv_wr.sg_list = &ctxt->sge[0];
522         recv_wr.num_sge = ctxt->count;
523         recv_wr.wr_id = (u64)(unsigned long)ctxt;
524 
525         svc_xprt_get(&xprt->sc_xprt);
526         ret = ib_post_recv(xprt->sc_qp, &recv_wr, &bad_recv_wr);
527         if (ret) {
528                 svc_rdma_unmap_dma(ctxt);
529                 svc_rdma_put_context(ctxt, 1);
530                 svc_xprt_put(&xprt->sc_xprt);
531         }
532         return ret;
533 
534  err_put_ctxt:
535         svc_rdma_unmap_dma(ctxt);
536         svc_rdma_put_context(ctxt, 1);
537         return -ENOMEM;
538 }
539 
540 /*
541  * This function handles the CONNECT_REQUEST event on a listening
542  * endpoint. It is passed the cma_id for the _new_ connection. The context in
543  * this cma_id is inherited from the listening cma_id and is the svc_xprt
544  * structure for the listening endpoint.
545  *
546  * This function creates a new xprt for the new connection and enqueues it on
547  * the accept queue for the listent xprt. When the listen thread is kicked, it
548  * will call the recvfrom method on the listen xprt which will accept the new
549  * connection.
550  */
551 static void handle_connect_req(struct rdma_cm_id *new_cma_id, size_t client_ird)
552 {
553         struct svcxprt_rdma *listen_xprt = new_cma_id->context;
554         struct svcxprt_rdma *newxprt;
555         struct sockaddr *sa;
556 
557         /* Create a new transport */
558         newxprt = rdma_create_xprt(listen_xprt->sc_xprt.xpt_server, 0);
559         if (!newxprt) {
560                 dprintk("svcrdma: failed to create new transport\n");
561                 return;
562         }
563         newxprt->sc_cm_id = new_cma_id;
564         new_cma_id->context = newxprt;
565         dprintk("svcrdma: Creating newxprt=%p, cm_id=%p, listenxprt=%p\n",
566                 newxprt, newxprt->sc_cm_id, listen_xprt);
567 
568         /* Save client advertised inbound read limit for use later in accept. */
569         newxprt->sc_ord = client_ird;
570 
571         /* Set the local and remote addresses in the transport */
572         sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.dst_addr;
573         svc_xprt_set_remote(&newxprt->sc_xprt, sa, svc_addr_len(sa));
574         sa = (struct sockaddr *)&newxprt->sc_cm_id->route.addr.src_addr;
575         svc_xprt_set_local(&newxprt->sc_xprt, sa, svc_addr_len(sa));
576 
577         /*
578          * Enqueue the new transport on the accept queue of the listening
579          * transport
580          */
581         spin_lock_bh(&listen_xprt->sc_lock);
582         list_add_tail(&newxprt->sc_accept_q, &listen_xprt->sc_accept_q);
583         spin_unlock_bh(&listen_xprt->sc_lock);
584 
585         set_bit(XPT_CONN, &listen_xprt->sc_xprt.xpt_flags);
586         svc_xprt_enqueue(&listen_xprt->sc_xprt);
587 }
588 
589 /*
590  * Handles events generated on the listening endpoint. These events will be
591  * either be incoming connect requests or adapter removal  events.
592  */
593 static int rdma_listen_handler(struct rdma_cm_id *cma_id,
594                                struct rdma_cm_event *event)
595 {
596         struct svcxprt_rdma *xprt = cma_id->context;
597         int ret = 0;
598 
599         switch (event->event) {
600         case RDMA_CM_EVENT_CONNECT_REQUEST:
601                 dprintk("svcrdma: Connect request on cma_id=%p, xprt = %p, "
602                         "event = %s (%d)\n", cma_id, cma_id->context,
603                         rdma_event_msg(event->event), event->event);
604                 handle_connect_req(cma_id,
605                                    event->param.conn.initiator_depth);
606                 break;
607 
608         case RDMA_CM_EVENT_ESTABLISHED:
609                 /* Accept complete */
610                 dprintk("svcrdma: Connection completed on LISTEN xprt=%p, "
611                         "cm_id=%p\n", xprt, cma_id);
612                 break;
613 
614         case RDMA_CM_EVENT_DEVICE_REMOVAL:
615                 dprintk("svcrdma: Device removal xprt=%p, cm_id=%p\n",
616                         xprt, cma_id);
617                 if (xprt)
618                         set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
619                 break;
620 
621         default:
622                 dprintk("svcrdma: Unexpected event on listening endpoint %p, "
623                         "event = %s (%d)\n", cma_id,
624                         rdma_event_msg(event->event), event->event);
625                 break;
626         }
627 
628         return ret;
629 }
630 
631 static int rdma_cma_handler(struct rdma_cm_id *cma_id,
632                             struct rdma_cm_event *event)
633 {
634         struct svc_xprt *xprt = cma_id->context;
635         struct svcxprt_rdma *rdma =
636                 container_of(xprt, struct svcxprt_rdma, sc_xprt);
637         switch (event->event) {
638         case RDMA_CM_EVENT_ESTABLISHED:
639                 /* Accept complete */
640                 svc_xprt_get(xprt);
641                 dprintk("svcrdma: Connection completed on DTO xprt=%p, "
642                         "cm_id=%p\n", xprt, cma_id);
643                 clear_bit(RDMAXPRT_CONN_PENDING, &rdma->sc_flags);
644                 svc_xprt_enqueue(xprt);
645                 break;
646         case RDMA_CM_EVENT_DISCONNECTED:
647                 dprintk("svcrdma: Disconnect on DTO xprt=%p, cm_id=%p\n",
648                         xprt, cma_id);
649                 if (xprt) {
650                         set_bit(XPT_CLOSE, &xprt->xpt_flags);
651                         svc_xprt_enqueue(xprt);
652                         svc_xprt_put(xprt);
653                 }
654                 break;
655         case RDMA_CM_EVENT_DEVICE_REMOVAL:
656                 dprintk("svcrdma: Device removal cma_id=%p, xprt = %p, "
657                         "event = %s (%d)\n", cma_id, xprt,
658                         rdma_event_msg(event->event), event->event);
659                 if (xprt) {
660                         set_bit(XPT_CLOSE, &xprt->xpt_flags);
661                         svc_xprt_enqueue(xprt);
662                         svc_xprt_put(xprt);
663                 }
664                 break;
665         default:
666                 dprintk("svcrdma: Unexpected event on DTO endpoint %p, "
667                         "event = %s (%d)\n", cma_id,
668                         rdma_event_msg(event->event), event->event);
669                 break;
670         }
671         return 0;
672 }
673 
674 /*
675  * Create a listening RDMA service endpoint.
676  */
677 static struct svc_xprt *svc_rdma_create(struct svc_serv *serv,
678                                         struct net *net,
679                                         struct sockaddr *sa, int salen,
680                                         int flags)
681 {
682         struct rdma_cm_id *listen_id;
683         struct svcxprt_rdma *cma_xprt;
684         int ret;
685 
686         dprintk("svcrdma: Creating RDMA socket\n");
687         if (sa->sa_family != AF_INET) {
688                 dprintk("svcrdma: Address family %d is not supported.\n", sa->sa_family);
689                 return ERR_PTR(-EAFNOSUPPORT);
690         }
691         cma_xprt = rdma_create_xprt(serv, 1);
692         if (!cma_xprt)
693                 return ERR_PTR(-ENOMEM);
694 
695         listen_id = rdma_create_id(rdma_listen_handler, cma_xprt, RDMA_PS_TCP,
696                                    IB_QPT_RC);
697         if (IS_ERR(listen_id)) {
698                 ret = PTR_ERR(listen_id);
699                 dprintk("svcrdma: rdma_create_id failed = %d\n", ret);
700                 goto err0;
701         }
702 
703         ret = rdma_bind_addr(listen_id, sa);
704         if (ret) {
705                 dprintk("svcrdma: rdma_bind_addr failed = %d\n", ret);
706                 goto err1;
707         }
708         cma_xprt->sc_cm_id = listen_id;
709 
710         ret = rdma_listen(listen_id, RPCRDMA_LISTEN_BACKLOG);
711         if (ret) {
712                 dprintk("svcrdma: rdma_listen failed = %d\n", ret);
713                 goto err1;
714         }
715 
716         /*
717          * We need to use the address from the cm_id in case the
718          * caller specified 0 for the port number.
719          */
720         sa = (struct sockaddr *)&cma_xprt->sc_cm_id->route.addr.src_addr;
721         svc_xprt_set_local(&cma_xprt->sc_xprt, sa, salen);
722 
723         return &cma_xprt->sc_xprt;
724 
725  err1:
726         rdma_destroy_id(listen_id);
727  err0:
728         kfree(cma_xprt);
729         return ERR_PTR(ret);
730 }
731 
732 static struct svc_rdma_fastreg_mr *rdma_alloc_frmr(struct svcxprt_rdma *xprt)
733 {
734         struct ib_mr *mr;
735         struct ib_fast_reg_page_list *pl;
736         struct svc_rdma_fastreg_mr *frmr;
737         u32 num_sg;
738 
739         frmr = kmalloc(sizeof(*frmr), GFP_KERNEL);
740         if (!frmr)
741                 goto err;
742 
743         num_sg = min_t(u32, RPCSVC_MAXPAGES, xprt->sc_frmr_pg_list_len);
744         mr = ib_alloc_mr(xprt->sc_pd, IB_MR_TYPE_MEM_REG, num_sg);
745         if (IS_ERR(mr))
746                 goto err_free_frmr;
747 
748         pl = ib_alloc_fast_reg_page_list(xprt->sc_cm_id->device,
749                                          num_sg);
750         if (IS_ERR(pl))
751                 goto err_free_mr;
752 
753         frmr->mr = mr;
754         frmr->page_list = pl;
755         INIT_LIST_HEAD(&frmr->frmr_list);
756         return frmr;
757 
758  err_free_mr:
759         ib_dereg_mr(mr);
760  err_free_frmr:
761         kfree(frmr);
762  err:
763         return ERR_PTR(-ENOMEM);
764 }
765 
766 static void rdma_dealloc_frmr_q(struct svcxprt_rdma *xprt)
767 {
768         struct svc_rdma_fastreg_mr *frmr;
769 
770         while (!list_empty(&xprt->sc_frmr_q)) {
771                 frmr = list_entry(xprt->sc_frmr_q.next,
772                                   struct svc_rdma_fastreg_mr, frmr_list);
773                 list_del_init(&frmr->frmr_list);
774                 ib_dereg_mr(frmr->mr);
775                 ib_free_fast_reg_page_list(frmr->page_list);
776                 kfree(frmr);
777         }
778 }
779 
780 struct svc_rdma_fastreg_mr *svc_rdma_get_frmr(struct svcxprt_rdma *rdma)
781 {
782         struct svc_rdma_fastreg_mr *frmr = NULL;
783 
784         spin_lock_bh(&rdma->sc_frmr_q_lock);
785         if (!list_empty(&rdma->sc_frmr_q)) {
786                 frmr = list_entry(rdma->sc_frmr_q.next,
787                                   struct svc_rdma_fastreg_mr, frmr_list);
788                 list_del_init(&frmr->frmr_list);
789                 frmr->map_len = 0;
790                 frmr->page_list_len = 0;
791         }
792         spin_unlock_bh(&rdma->sc_frmr_q_lock);
793         if (frmr)
794                 return frmr;
795 
796         return rdma_alloc_frmr(rdma);
797 }
798 
799 static void frmr_unmap_dma(struct svcxprt_rdma *xprt,
800                            struct svc_rdma_fastreg_mr *frmr)
801 {
802         int page_no;
803         for (page_no = 0; page_no < frmr->page_list_len; page_no++) {
804                 dma_addr_t addr = frmr->page_list->page_list[page_no];
805                 if (ib_dma_mapping_error(frmr->mr->device, addr))
806                         continue;
807                 atomic_dec(&xprt->sc_dma_used);
808                 ib_dma_unmap_page(frmr->mr->device, addr, PAGE_SIZE,
809                                   frmr->direction);
810         }
811 }
812 
813 void svc_rdma_put_frmr(struct svcxprt_rdma *rdma,
814                        struct svc_rdma_fastreg_mr *frmr)
815 {
816         if (frmr) {
817                 frmr_unmap_dma(rdma, frmr);
818                 spin_lock_bh(&rdma->sc_frmr_q_lock);
819                 WARN_ON_ONCE(!list_empty(&frmr->frmr_list));
820                 list_add(&frmr->frmr_list, &rdma->sc_frmr_q);
821                 spin_unlock_bh(&rdma->sc_frmr_q_lock);
822         }
823 }
824 
825 /*
826  * This is the xpo_recvfrom function for listening endpoints. Its
827  * purpose is to accept incoming connections. The CMA callback handler
828  * has already created a new transport and attached it to the new CMA
829  * ID.
830  *
831  * There is a queue of pending connections hung on the listening
832  * transport. This queue contains the new svc_xprt structure. This
833  * function takes svc_xprt structures off the accept_q and completes
834  * the connection.
835  */
836 static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
837 {
838         struct svcxprt_rdma *listen_rdma;
839         struct svcxprt_rdma *newxprt = NULL;
840         struct rdma_conn_param conn_param;
841         struct ib_cq_init_attr cq_attr = {};
842         struct ib_qp_init_attr qp_attr;
843         struct ib_device_attr devattr;
844         int uninitialized_var(dma_mr_acc);
845         int need_dma_mr = 0;
846         int ret;
847         int i;
848 
849         listen_rdma = container_of(xprt, struct svcxprt_rdma, sc_xprt);
850         clear_bit(XPT_CONN, &xprt->xpt_flags);
851         /* Get the next entry off the accept list */
852         spin_lock_bh(&listen_rdma->sc_lock);
853         if (!list_empty(&listen_rdma->sc_accept_q)) {
854                 newxprt = list_entry(listen_rdma->sc_accept_q.next,
855                                      struct svcxprt_rdma, sc_accept_q);
856                 list_del_init(&newxprt->sc_accept_q);
857         }
858         if (!list_empty(&listen_rdma->sc_accept_q))
859                 set_bit(XPT_CONN, &listen_rdma->sc_xprt.xpt_flags);
860         spin_unlock_bh(&listen_rdma->sc_lock);
861         if (!newxprt)
862                 return NULL;
863 
864         dprintk("svcrdma: newxprt from accept queue = %p, cm_id=%p\n",
865                 newxprt, newxprt->sc_cm_id);
866 
867         ret = ib_query_device(newxprt->sc_cm_id->device, &devattr);
868         if (ret) {
869                 dprintk("svcrdma: could not query device attributes on "
870                         "device %p, rc=%d\n", newxprt->sc_cm_id->device, ret);
871                 goto errout;
872         }
873 
874         /* Qualify the transport resource defaults with the
875          * capabilities of this particular device */
876         newxprt->sc_max_sge = min((size_t)devattr.max_sge,
877                                   (size_t)RPCSVC_MAXPAGES);
878         newxprt->sc_max_sge_rd = min_t(size_t, devattr.max_sge_rd,
879                                        RPCSVC_MAXPAGES);
880         newxprt->sc_max_requests = min((size_t)devattr.max_qp_wr,
881                                    (size_t)svcrdma_max_requests);
882         newxprt->sc_sq_depth = RPCRDMA_SQ_DEPTH_MULT * newxprt->sc_max_requests;
883 
884         /*
885          * Limit ORD based on client limit, local device limit, and
886          * configured svcrdma limit.
887          */
888         newxprt->sc_ord = min_t(size_t, devattr.max_qp_rd_atom, newxprt->sc_ord);
889         newxprt->sc_ord = min_t(size_t, svcrdma_ord, newxprt->sc_ord);
890 
891         newxprt->sc_pd = ib_alloc_pd(newxprt->sc_cm_id->device);
892         if (IS_ERR(newxprt->sc_pd)) {
893                 dprintk("svcrdma: error creating PD for connect request\n");
894                 goto errout;
895         }
896         cq_attr.cqe = newxprt->sc_sq_depth;
897         newxprt->sc_sq_cq = ib_create_cq(newxprt->sc_cm_id->device,
898                                          sq_comp_handler,
899                                          cq_event_handler,
900                                          newxprt,
901                                          &cq_attr);
902         if (IS_ERR(newxprt->sc_sq_cq)) {
903                 dprintk("svcrdma: error creating SQ CQ for connect request\n");
904                 goto errout;
905         }
906         cq_attr.cqe = newxprt->sc_max_requests;
907         newxprt->sc_rq_cq = ib_create_cq(newxprt->sc_cm_id->device,
908                                          rq_comp_handler,
909                                          cq_event_handler,
910                                          newxprt,
911                                          &cq_attr);
912         if (IS_ERR(newxprt->sc_rq_cq)) {
913                 dprintk("svcrdma: error creating RQ CQ for connect request\n");
914                 goto errout;
915         }
916 
917         memset(&qp_attr, 0, sizeof qp_attr);
918         qp_attr.event_handler = qp_event_handler;
919         qp_attr.qp_context = &newxprt->sc_xprt;
920         qp_attr.cap.max_send_wr = newxprt->sc_sq_depth;
921         qp_attr.cap.max_recv_wr = newxprt->sc_max_requests;
922         qp_attr.cap.max_send_sge = newxprt->sc_max_sge;
923         qp_attr.cap.max_recv_sge = newxprt->sc_max_sge;
924         qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
925         qp_attr.qp_type = IB_QPT_RC;
926         qp_attr.send_cq = newxprt->sc_sq_cq;
927         qp_attr.recv_cq = newxprt->sc_rq_cq;
928         dprintk("svcrdma: newxprt->sc_cm_id=%p, newxprt->sc_pd=%p\n"
929                 "    cm_id->device=%p, sc_pd->device=%p\n"
930                 "    cap.max_send_wr = %d\n"
931                 "    cap.max_recv_wr = %d\n"
932                 "    cap.max_send_sge = %d\n"
933                 "    cap.max_recv_sge = %d\n",
934                 newxprt->sc_cm_id, newxprt->sc_pd,
935                 newxprt->sc_cm_id->device, newxprt->sc_pd->device,
936                 qp_attr.cap.max_send_wr,
937                 qp_attr.cap.max_recv_wr,
938                 qp_attr.cap.max_send_sge,
939                 qp_attr.cap.max_recv_sge);
940 
941         ret = rdma_create_qp(newxprt->sc_cm_id, newxprt->sc_pd, &qp_attr);
942         if (ret) {
943                 dprintk("svcrdma: failed to create QP, ret=%d\n", ret);
944                 goto errout;
945         }
946         newxprt->sc_qp = newxprt->sc_cm_id->qp;
947 
948         /*
949          * Use the most secure set of MR resources based on the
950          * transport type and available memory management features in
951          * the device. Here's the table implemented below:
952          *
953          *              Fast    Global  DMA     Remote WR
954          *              Reg     LKEY    MR      Access
955          *              Sup'd   Sup'd   Needed  Needed
956          *
957          * IWARP        N       N       Y       Y
958          *              N       Y       Y       Y
959          *              Y       N       Y       N
960          *              Y       Y       N       -
961          *
962          * IB           N       N       Y       N
963          *              N       Y       N       -
964          *              Y       N       Y       N
965          *              Y       Y       N       -
966          *
967          * NB:  iWARP requires remote write access for the data sink
968          *      of an RDMA_READ. IB does not.
969          */
970         newxprt->sc_reader = rdma_read_chunk_lcl;
971         if (devattr.device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
972                 newxprt->sc_frmr_pg_list_len =
973                         devattr.max_fast_reg_page_list_len;
974                 newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_FAST_REG;
975                 newxprt->sc_reader = rdma_read_chunk_frmr;
976         }
977 
978         /*
979          * Determine if a DMA MR is required and if so, what privs are required
980          */
981         if (!rdma_protocol_iwarp(newxprt->sc_cm_id->device,
982                                  newxprt->sc_cm_id->port_num) &&
983             !rdma_ib_or_roce(newxprt->sc_cm_id->device,
984                              newxprt->sc_cm_id->port_num))
985                 goto errout;
986 
987         if (!(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG) ||
988             !(devattr.device_cap_flags & IB_DEVICE_LOCAL_DMA_LKEY)) {
989                 need_dma_mr = 1;
990                 dma_mr_acc = IB_ACCESS_LOCAL_WRITE;
991                 if (rdma_protocol_iwarp(newxprt->sc_cm_id->device,
992                                         newxprt->sc_cm_id->port_num) &&
993                     !(newxprt->sc_dev_caps & SVCRDMA_DEVCAP_FAST_REG))
994                         dma_mr_acc |= IB_ACCESS_REMOTE_WRITE;
995         }
996 
997         if (rdma_protocol_iwarp(newxprt->sc_cm_id->device,
998                                 newxprt->sc_cm_id->port_num))
999                 newxprt->sc_dev_caps |= SVCRDMA_DEVCAP_READ_W_INV;
1000 
1001         /* Create the DMA MR if needed, otherwise, use the DMA LKEY */
1002         if (need_dma_mr) {
1003                 /* Register all of physical memory */
1004                 newxprt->sc_phys_mr =
1005                         ib_get_dma_mr(newxprt->sc_pd, dma_mr_acc);
1006                 if (IS_ERR(newxprt->sc_phys_mr)) {
1007                         dprintk("svcrdma: Failed to create DMA MR ret=%d\n",
1008                                 ret);
1009                         goto errout;
1010                 }
1011                 newxprt->sc_dma_lkey = newxprt->sc_phys_mr->lkey;
1012         } else
1013                 newxprt->sc_dma_lkey =
1014                         newxprt->sc_cm_id->device->local_dma_lkey;
1015 
1016         /* Post receive buffers */
1017         for (i = 0; i < newxprt->sc_max_requests; i++) {
1018                 ret = svc_rdma_post_recv(newxprt);
1019                 if (ret) {
1020                         dprintk("svcrdma: failure posting receive buffers\n");
1021                         goto errout;
1022                 }
1023         }
1024 
1025         /* Swap out the handler */
1026         newxprt->sc_cm_id->event_handler = rdma_cma_handler;
1027 
1028         /*
1029          * Arm the CQs for the SQ and RQ before accepting so we can't
1030          * miss the first message
1031          */
1032         ib_req_notify_cq(newxprt->sc_sq_cq, IB_CQ_NEXT_COMP);
1033         ib_req_notify_cq(newxprt->sc_rq_cq, IB_CQ_NEXT_COMP);
1034 
1035         /* Accept Connection */
1036         set_bit(RDMAXPRT_CONN_PENDING, &newxprt->sc_flags);
1037         memset(&conn_param, 0, sizeof conn_param);
1038         conn_param.responder_resources = 0;
1039         conn_param.initiator_depth = newxprt->sc_ord;
1040         ret = rdma_accept(newxprt->sc_cm_id, &conn_param);
1041         if (ret) {
1042                 dprintk("svcrdma: failed to accept new connection, ret=%d\n",
1043                        ret);
1044                 goto errout;
1045         }
1046 
1047         dprintk("svcrdma: new connection %p accepted with the following "
1048                 "attributes:\n"
1049                 "    local_ip        : %pI4\n"
1050                 "    local_port      : %d\n"
1051                 "    remote_ip       : %pI4\n"
1052                 "    remote_port     : %d\n"
1053                 "    max_sge         : %d\n"
1054                 "    max_sge_rd      : %d\n"
1055                 "    sq_depth        : %d\n"
1056                 "    max_requests    : %d\n"
1057                 "    ord             : %d\n",
1058                 newxprt,
1059                 &((struct sockaddr_in *)&newxprt->sc_cm_id->
1060                          route.addr.src_addr)->sin_addr.s_addr,
1061                 ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id->
1062                        route.addr.src_addr)->sin_port),
1063                 &((struct sockaddr_in *)&newxprt->sc_cm_id->
1064                          route.addr.dst_addr)->sin_addr.s_addr,
1065                 ntohs(((struct sockaddr_in *)&newxprt->sc_cm_id->
1066                        route.addr.dst_addr)->sin_port),
1067                 newxprt->sc_max_sge,
1068                 newxprt->sc_max_sge_rd,
1069                 newxprt->sc_sq_depth,
1070                 newxprt->sc_max_requests,
1071                 newxprt->sc_ord);
1072 
1073         return &newxprt->sc_xprt;
1074 
1075  errout:
1076         dprintk("svcrdma: failure accepting new connection rc=%d.\n", ret);
1077         /* Take a reference in case the DTO handler runs */
1078         svc_xprt_get(&newxprt->sc_xprt);
1079         if (newxprt->sc_qp && !IS_ERR(newxprt->sc_qp))
1080                 ib_destroy_qp(newxprt->sc_qp);
1081         rdma_destroy_id(newxprt->sc_cm_id);
1082         /* This call to put will destroy the transport */
1083         svc_xprt_put(&newxprt->sc_xprt);
1084         return NULL;
1085 }
1086 
1087 static void svc_rdma_release_rqst(struct svc_rqst *rqstp)
1088 {
1089 }
1090 
1091 /*
1092  * When connected, an svc_xprt has at least two references:
1093  *
1094  * - A reference held by the cm_id between the ESTABLISHED and
1095  *   DISCONNECTED events. If the remote peer disconnected first, this
1096  *   reference could be gone.
1097  *
1098  * - A reference held by the svc_recv code that called this function
1099  *   as part of close processing.
1100  *
1101  * At a minimum one references should still be held.
1102  */
1103 static void svc_rdma_detach(struct svc_xprt *xprt)
1104 {
1105         struct svcxprt_rdma *rdma =
1106                 container_of(xprt, struct svcxprt_rdma, sc_xprt);
1107         dprintk("svc: svc_rdma_detach(%p)\n", xprt);
1108 
1109         /* Disconnect and flush posted WQE */
1110         rdma_disconnect(rdma->sc_cm_id);
1111 }
1112 
1113 static void __svc_rdma_free(struct work_struct *work)
1114 {
1115         struct svcxprt_rdma *rdma =
1116                 container_of(work, struct svcxprt_rdma, sc_work);
1117         dprintk("svcrdma: svc_rdma_free(%p)\n", rdma);
1118 
1119         /* We should only be called from kref_put */
1120         if (atomic_read(&rdma->sc_xprt.xpt_ref.refcount) != 0)
1121                 pr_err("svcrdma: sc_xprt still in use? (%d)\n",
1122                        atomic_read(&rdma->sc_xprt.xpt_ref.refcount));
1123 
1124         /*
1125          * Destroy queued, but not processed read completions. Note
1126          * that this cleanup has to be done before destroying the
1127          * cm_id because the device ptr is needed to unmap the dma in
1128          * svc_rdma_put_context.
1129          */
1130         while (!list_empty(&rdma->sc_read_complete_q)) {
1131                 struct svc_rdma_op_ctxt *ctxt;
1132                 ctxt = list_entry(rdma->sc_read_complete_q.next,
1133                                   struct svc_rdma_op_ctxt,
1134                                   dto_q);
1135                 list_del_init(&ctxt->dto_q);
1136                 svc_rdma_put_context(ctxt, 1);
1137         }
1138 
1139         /* Destroy queued, but not processed recv completions */
1140         while (!list_empty(&rdma->sc_rq_dto_q)) {
1141                 struct svc_rdma_op_ctxt *ctxt;
1142                 ctxt = list_entry(rdma->sc_rq_dto_q.next,
1143                                   struct svc_rdma_op_ctxt,
1144                                   dto_q);
1145                 list_del_init(&ctxt->dto_q);
1146                 svc_rdma_put_context(ctxt, 1);
1147         }
1148 
1149         /* Warn if we leaked a resource or under-referenced */
1150         if (atomic_read(&rdma->sc_ctxt_used) != 0)
1151                 pr_err("svcrdma: ctxt still in use? (%d)\n",
1152                        atomic_read(&rdma->sc_ctxt_used));
1153         if (atomic_read(&rdma->sc_dma_used) != 0)
1154                 pr_err("svcrdma: dma still in use? (%d)\n",
1155                        atomic_read(&rdma->sc_dma_used));
1156 
1157         /* De-allocate fastreg mr */
1158         rdma_dealloc_frmr_q(rdma);
1159 
1160         /* Destroy the QP if present (not a listener) */
1161         if (rdma->sc_qp && !IS_ERR(rdma->sc_qp))
1162                 ib_destroy_qp(rdma->sc_qp);
1163 
1164         if (rdma->sc_sq_cq && !IS_ERR(rdma->sc_sq_cq))
1165                 ib_destroy_cq(rdma->sc_sq_cq);
1166 
1167         if (rdma->sc_rq_cq && !IS_ERR(rdma->sc_rq_cq))
1168                 ib_destroy_cq(rdma->sc_rq_cq);
1169 
1170         if (rdma->sc_phys_mr && !IS_ERR(rdma->sc_phys_mr))
1171                 ib_dereg_mr(rdma->sc_phys_mr);
1172 
1173         if (rdma->sc_pd && !IS_ERR(rdma->sc_pd))
1174                 ib_dealloc_pd(rdma->sc_pd);
1175 
1176         /* Destroy the CM ID */
1177         rdma_destroy_id(rdma->sc_cm_id);
1178 
1179         kfree(rdma);
1180 }
1181 
1182 static void svc_rdma_free(struct svc_xprt *xprt)
1183 {
1184         struct svcxprt_rdma *rdma =
1185                 container_of(xprt, struct svcxprt_rdma, sc_xprt);
1186         INIT_WORK(&rdma->sc_work, __svc_rdma_free);
1187         queue_work(svc_rdma_wq, &rdma->sc_work);
1188 }
1189 
1190 static int svc_rdma_has_wspace(struct svc_xprt *xprt)
1191 {
1192         struct svcxprt_rdma *rdma =
1193                 container_of(xprt, struct svcxprt_rdma, sc_xprt);
1194 
1195         /*
1196          * If there are already waiters on the SQ,
1197          * return false.
1198          */
1199         if (waitqueue_active(&rdma->sc_send_wait))
1200                 return 0;
1201 
1202         /* Otherwise return true. */
1203         return 1;
1204 }
1205 
1206 static int svc_rdma_secure_port(struct svc_rqst *rqstp)
1207 {
1208         return 1;
1209 }
1210 
1211 int svc_rdma_send(struct svcxprt_rdma *xprt, struct ib_send_wr *wr)
1212 {
1213         struct ib_send_wr *bad_wr, *n_wr;
1214         int wr_count;
1215         int i;
1216         int ret;
1217 
1218         if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags))
1219                 return -ENOTCONN;
1220 
1221         wr_count = 1;
1222         for (n_wr = wr->next; n_wr; n_wr = n_wr->next)
1223                 wr_count++;
1224 
1225         /* If the SQ is full, wait until an SQ entry is available */
1226         while (1) {
1227                 spin_lock_bh(&xprt->sc_lock);
1228                 if (xprt->sc_sq_depth < atomic_read(&xprt->sc_sq_count) + wr_count) {
1229                         spin_unlock_bh(&xprt->sc_lock);
1230                         atomic_inc(&rdma_stat_sq_starve);
1231 
1232                         /* See if we can opportunistically reap SQ WR to make room */
1233                         sq_cq_reap(xprt);
1234 
1235                         /* Wait until SQ WR available if SQ still full */
1236                         wait_event(xprt->sc_send_wait,
1237                                    atomic_read(&xprt->sc_sq_count) <
1238                                    xprt->sc_sq_depth);
1239                         if (test_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags))
1240                                 return -ENOTCONN;
1241                         continue;
1242                 }
1243                 /* Take a transport ref for each WR posted */
1244                 for (i = 0; i < wr_count; i++)
1245                         svc_xprt_get(&xprt->sc_xprt);
1246 
1247                 /* Bump used SQ WR count and post */
1248                 atomic_add(wr_count, &xprt->sc_sq_count);
1249                 ret = ib_post_send(xprt->sc_qp, wr, &bad_wr);
1250                 if (ret) {
1251                         set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
1252                         atomic_sub(wr_count, &xprt->sc_sq_count);
1253                         for (i = 0; i < wr_count; i ++)
1254                                 svc_xprt_put(&xprt->sc_xprt);
1255                         dprintk("svcrdma: failed to post SQ WR rc=%d, "
1256                                "sc_sq_count=%d, sc_sq_depth=%d\n",
1257                                ret, atomic_read(&xprt->sc_sq_count),
1258                                xprt->sc_sq_depth);
1259                 }
1260                 spin_unlock_bh(&xprt->sc_lock);
1261                 if (ret)
1262                         wake_up(&xprt->sc_send_wait);
1263                 break;
1264         }
1265         return ret;
1266 }
1267 
1268 void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
1269                          enum rpcrdma_errcode err)
1270 {
1271         struct ib_send_wr err_wr;
1272         struct page *p;
1273         struct svc_rdma_op_ctxt *ctxt;
1274         __be32 *va;
1275         int length;
1276         int ret;
1277 
1278         p = alloc_page(GFP_KERNEL | __GFP_NOFAIL);
1279         va = page_address(p);
1280 
1281         /* XDR encode error */
1282         length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va);
1283 
1284         ctxt = svc_rdma_get_context(xprt);
1285         ctxt->direction = DMA_FROM_DEVICE;
1286         ctxt->count = 1;
1287         ctxt->pages[0] = p;
1288 
1289         /* Prepare SGE for local address */
1290         ctxt->sge[0].addr = ib_dma_map_page(xprt->sc_cm_id->device,
1291                                             p, 0, length, DMA_FROM_DEVICE);
1292         if (ib_dma_mapping_error(xprt->sc_cm_id->device, ctxt->sge[0].addr)) {
1293                 put_page(p);
1294                 svc_rdma_put_context(ctxt, 1);
1295                 return;
1296         }
1297         atomic_inc(&xprt->sc_dma_used);
1298         ctxt->sge[0].lkey = xprt->sc_dma_lkey;
1299         ctxt->sge[0].length = length;
1300 
1301         /* Prepare SEND WR */
1302         memset(&err_wr, 0, sizeof err_wr);
1303         ctxt->wr_op = IB_WR_SEND;
1304         err_wr.wr_id = (unsigned long)ctxt;
1305         err_wr.sg_list = ctxt->sge;
1306         err_wr.num_sge = 1;
1307         err_wr.opcode = IB_WR_SEND;
1308         err_wr.send_flags = IB_SEND_SIGNALED;
1309 
1310         /* Post It */
1311         ret = svc_rdma_send(xprt, &err_wr);
1312         if (ret) {
1313                 dprintk("svcrdma: Error %d posting send for protocol error\n",
1314                         ret);
1315                 svc_rdma_unmap_dma(ctxt);
1316                 svc_rdma_put_context(ctxt, 1);
1317         }
1318 }
1319 

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