2 * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3 * Copyright (c) 2005, 2006 Cisco Systems. All rights reserved.
5 * This software is available to you under a choice of one of two
6 * licenses. You may choose to be licensed under the terms of the GNU
7 * General Public License (GPL) Version 2, available from the file
8 * COPYING in the main directory of this source tree, or the
9 * OpenIB.org BSD license below:
11 * Redistribution and use in source and binary forms, with or
12 * without modification, are permitted provided that the following
15 * - Redistributions of source code must retain the above
16 * copyright notice, this list of conditions and the following
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials
22 * provided with the distribution.
24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
33 * $Id: iser_verbs.c 7051 2006-05-10 12:29:11Z ogerlitz $
35 #include <linux/kernel.h>
36 #include <linux/module.h>
37 #include <linux/delay.h>
38 #include <linux/version.h>
40 #include "iscsi_iser.h"
42 #define ISCSI_ISER_MAX_CONN 8
43 #define ISER_MAX_CQ_LEN ((ISER_QP_MAX_RECV_DTOS + \
44 ISER_QP_MAX_REQ_DTOS) * \
47 static void iser_cq_tasklet_fn(unsigned long data);
48 static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
50 static void iser_cq_event_callback(struct ib_event *cause, void *context)
52 iser_err("got cq event %d \n", cause->event);
55 static void iser_qp_event_callback(struct ib_event *cause, void *context)
57 iser_err("got qp event %d\n",cause->event);
61 * iser_create_device_ib_res - creates Protection Domain (PD), Completion
62 * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
65 * returns 0 on success, -1 on failure
67 static int iser_create_device_ib_res(struct iser_device *device)
69 device->pd = ib_alloc_pd(device->ib_device);
70 if (IS_ERR(device->pd))
73 device->cq = ib_create_cq(device->ib_device,
75 iser_cq_event_callback,
78 if (IS_ERR(device->cq))
81 if (ib_req_notify_cq(device->cq, IB_CQ_NEXT_COMP))
84 tasklet_init(&device->cq_tasklet,
86 (unsigned long)device);
88 device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
89 IB_ACCESS_REMOTE_WRITE |
90 IB_ACCESS_REMOTE_READ);
91 if (IS_ERR(device->mr))
97 tasklet_kill(&device->cq_tasklet);
99 ib_destroy_cq(device->cq);
101 ib_dealloc_pd(device->pd);
103 iser_err("failed to allocate an IB resource\n");
108 * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
109 * CQ and PD created with the device associated with the adapator.
111 static void iser_free_device_ib_res(struct iser_device *device)
113 BUG_ON(device->mr == NULL);
115 tasklet_kill(&device->cq_tasklet);
117 (void)ib_dereg_mr(device->mr);
118 (void)ib_destroy_cq(device->cq);
119 (void)ib_dealloc_pd(device->pd);
127 * iser_create_ib_conn_res - Creates FMR pool and Queue-Pair (QP)
129 * returns 0 on success, -1 on failure
131 static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
133 struct iser_device *device;
134 struct ib_qp_init_attr init_attr;
136 struct ib_fmr_pool_param params;
138 BUG_ON(ib_conn->device == NULL);
140 device = ib_conn->device;
142 ib_conn->page_vec = kmalloc(sizeof(struct iser_page_vec) +
143 (sizeof(u64) * (ISCSI_ISER_SG_TABLESIZE +1)),
145 if (!ib_conn->page_vec) {
149 ib_conn->page_vec->pages = (u64 *) (ib_conn->page_vec + 1);
151 params.page_shift = SHIFT_4K;
152 /* when the first/last SG element are not start/end *
153 * page aligned, the map whould be of N+1 pages */
154 params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
155 /* make the pool size twice the max number of SCSI commands *
156 * the ML is expected to queue, watermark for unmap at 50% */
157 params.pool_size = ISCSI_DEF_XMIT_CMDS_MAX * 2;
158 params.dirty_watermark = ISCSI_DEF_XMIT_CMDS_MAX;
160 params.flush_function = NULL;
161 params.access = (IB_ACCESS_LOCAL_WRITE |
162 IB_ACCESS_REMOTE_WRITE |
163 IB_ACCESS_REMOTE_READ);
165 ib_conn->fmr_pool = ib_create_fmr_pool(device->pd, ¶ms);
166 if (IS_ERR(ib_conn->fmr_pool)) {
167 ret = PTR_ERR(ib_conn->fmr_pool);
171 memset(&init_attr, 0, sizeof init_attr);
173 init_attr.event_handler = iser_qp_event_callback;
174 init_attr.qp_context = (void *)ib_conn;
175 init_attr.send_cq = device->cq;
176 init_attr.recv_cq = device->cq;
177 init_attr.cap.max_send_wr = ISER_QP_MAX_REQ_DTOS;
178 init_attr.cap.max_recv_wr = ISER_QP_MAX_RECV_DTOS;
179 init_attr.cap.max_send_sge = MAX_REGD_BUF_VECTOR_LEN;
180 init_attr.cap.max_recv_sge = 2;
181 init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
182 init_attr.qp_type = IB_QPT_RC;
184 ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
188 ib_conn->qp = ib_conn->cma_id->qp;
189 iser_err("setting conn %p cma_id %p: fmr_pool %p qp %p\n",
190 ib_conn, ib_conn->cma_id,
191 ib_conn->fmr_pool, ib_conn->cma_id->qp);
195 (void)ib_destroy_fmr_pool(ib_conn->fmr_pool);
197 kfree(ib_conn->page_vec);
199 iser_err("unable to alloc mem or create resource, err %d\n", ret);
204 * releases the FMR pool, QP and CMA ID objects, returns 0 on success,
207 static int iser_free_ib_conn_res(struct iser_conn *ib_conn)
209 BUG_ON(ib_conn == NULL);
211 iser_err("freeing conn %p cma_id %p fmr pool %p qp %p\n",
212 ib_conn, ib_conn->cma_id,
213 ib_conn->fmr_pool, ib_conn->qp);
215 /* qp is created only once both addr & route are resolved */
216 if (ib_conn->fmr_pool != NULL)
217 ib_destroy_fmr_pool(ib_conn->fmr_pool);
219 if (ib_conn->qp != NULL)
220 rdma_destroy_qp(ib_conn->cma_id);
222 if (ib_conn->cma_id != NULL)
223 rdma_destroy_id(ib_conn->cma_id);
225 ib_conn->fmr_pool = NULL;
227 ib_conn->cma_id = NULL;
228 kfree(ib_conn->page_vec);
234 * based on the resolved device node GUID see if there already allocated
235 * device for this device. If there's no such, create one.
238 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
240 struct iser_device *device;
242 mutex_lock(&ig.device_list_mutex);
244 list_for_each_entry(device, &ig.device_list, ig_list)
245 /* find if there's a match using the node GUID */
246 if (device->ib_device->node_guid == cma_id->device->node_guid)
249 device = kzalloc(sizeof *device, GFP_KERNEL);
253 /* assign this device to the device */
254 device->ib_device = cma_id->device;
255 /* init the device and link it into ig device list */
256 if (iser_create_device_ib_res(device)) {
261 list_add(&device->ig_list, &ig.device_list);
266 mutex_unlock(&ig.device_list_mutex);
270 /* if there's no demand for this device, release it */
271 static void iser_device_try_release(struct iser_device *device)
273 mutex_lock(&ig.device_list_mutex);
275 iser_err("device %p refcount %d\n",device,device->refcount);
276 if (!device->refcount) {
277 iser_free_device_ib_res(device);
278 list_del(&device->ig_list);
281 mutex_unlock(&ig.device_list_mutex);
284 int iser_conn_state_comp(struct iser_conn *ib_conn,
285 enum iser_ib_conn_state comp)
289 spin_lock_bh(&ib_conn->lock);
290 ret = (ib_conn->state == comp);
291 spin_unlock_bh(&ib_conn->lock);
295 static int iser_conn_state_comp_exch(struct iser_conn *ib_conn,
296 enum iser_ib_conn_state comp,
297 enum iser_ib_conn_state exch)
301 spin_lock_bh(&ib_conn->lock);
302 if ((ret = (ib_conn->state == comp)))
303 ib_conn->state = exch;
304 spin_unlock_bh(&ib_conn->lock);
309 * Frees all conn objects and deallocs conn descriptor
311 static void iser_conn_release(struct iser_conn *ib_conn)
313 struct iser_device *device = ib_conn->device;
315 BUG_ON(ib_conn->state != ISER_CONN_DOWN);
317 mutex_lock(&ig.connlist_mutex);
318 list_del(&ib_conn->conn_list);
319 mutex_unlock(&ig.connlist_mutex);
321 iser_free_ib_conn_res(ib_conn);
322 ib_conn->device = NULL;
323 /* on EVENT_ADDR_ERROR there's no device yet for this conn */
325 iser_device_try_release(device);
326 if (ib_conn->iser_conn)
327 ib_conn->iser_conn->ib_conn = NULL;
332 * triggers start of the disconnect procedures and wait for them to be done
334 void iser_conn_terminate(struct iser_conn *ib_conn)
338 /* change the ib conn state only if the conn is UP, however always call
339 * rdma_disconnect since this is the only way to cause the CMA to change
340 * the QP state to ERROR
343 iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP, ISER_CONN_TERMINATING);
344 err = rdma_disconnect(ib_conn->cma_id);
346 iser_err("Failed to disconnect, conn: 0x%p err %d\n",
349 wait_event_interruptible(ib_conn->wait,
350 ib_conn->state == ISER_CONN_DOWN);
352 iser_conn_release(ib_conn);
355 static void iser_connect_error(struct rdma_cm_id *cma_id)
357 struct iser_conn *ib_conn;
358 ib_conn = (struct iser_conn *)cma_id->context;
360 ib_conn->state = ISER_CONN_DOWN;
361 wake_up_interruptible(&ib_conn->wait);
364 static void iser_addr_handler(struct rdma_cm_id *cma_id)
366 struct iser_device *device;
367 struct iser_conn *ib_conn;
370 device = iser_device_find_by_ib_device(cma_id);
372 iser_err("device lookup/creation failed\n");
373 iser_connect_error(cma_id);
377 ib_conn = (struct iser_conn *)cma_id->context;
378 ib_conn->device = device;
380 ret = rdma_resolve_route(cma_id, 1000);
382 iser_err("resolve route failed: %d\n", ret);
383 iser_connect_error(cma_id);
387 static void iser_route_handler(struct rdma_cm_id *cma_id)
389 struct rdma_conn_param conn_param;
392 ret = iser_create_ib_conn_res((struct iser_conn *)cma_id->context);
396 iser_dbg("path.mtu is %d setting it to %d\n",
397 cma_id->route.path_rec->mtu, IB_MTU_1024);
399 /* we must set the MTU to 1024 as this is what the target is assuming */
400 if (cma_id->route.path_rec->mtu > IB_MTU_1024)
401 cma_id->route.path_rec->mtu = IB_MTU_1024;
403 memset(&conn_param, 0, sizeof conn_param);
404 conn_param.responder_resources = 4;
405 conn_param.initiator_depth = 1;
406 conn_param.retry_count = 7;
407 conn_param.rnr_retry_count = 6;
409 ret = rdma_connect(cma_id, &conn_param);
411 iser_err("failure connecting: %d\n", ret);
417 iser_connect_error(cma_id);
420 static void iser_connected_handler(struct rdma_cm_id *cma_id)
422 struct iser_conn *ib_conn;
424 ib_conn = (struct iser_conn *)cma_id->context;
425 ib_conn->state = ISER_CONN_UP;
426 wake_up_interruptible(&ib_conn->wait);
429 static void iser_disconnected_handler(struct rdma_cm_id *cma_id)
431 struct iser_conn *ib_conn;
433 ib_conn = (struct iser_conn *)cma_id->context;
434 ib_conn->disc_evt_flag = 1;
436 /* getting here when the state is UP means that the conn is being *
437 * terminated asynchronously from the iSCSI layer's perspective. */
438 if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
439 ISER_CONN_TERMINATING))
440 iscsi_conn_failure(ib_conn->iser_conn->iscsi_conn,
441 ISCSI_ERR_CONN_FAILED);
443 /* Complete the termination process if no posts are pending */
444 if ((atomic_read(&ib_conn->post_recv_buf_count) == 0) &&
445 (atomic_read(&ib_conn->post_send_buf_count) == 0)) {
446 ib_conn->state = ISER_CONN_DOWN;
447 wake_up_interruptible(&ib_conn->wait);
451 static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
455 iser_err("event %d conn %p id %p\n",event->event,cma_id->context,cma_id);
457 switch (event->event) {
458 case RDMA_CM_EVENT_ADDR_RESOLVED:
459 iser_addr_handler(cma_id);
461 case RDMA_CM_EVENT_ROUTE_RESOLVED:
462 iser_route_handler(cma_id);
464 case RDMA_CM_EVENT_ESTABLISHED:
465 iser_connected_handler(cma_id);
467 case RDMA_CM_EVENT_ADDR_ERROR:
468 case RDMA_CM_EVENT_ROUTE_ERROR:
469 case RDMA_CM_EVENT_CONNECT_ERROR:
470 case RDMA_CM_EVENT_UNREACHABLE:
471 case RDMA_CM_EVENT_REJECTED:
472 iser_err("event: %d, error: %d\n", event->event, event->status);
473 iser_connect_error(cma_id);
475 case RDMA_CM_EVENT_DISCONNECTED:
476 iser_disconnected_handler(cma_id);
478 case RDMA_CM_EVENT_DEVICE_REMOVAL:
479 iser_err("Device removal is currently unsupported\n");
483 iser_err("Unexpected RDMA CM event (%d)\n", event->event);
489 int iser_conn_init(struct iser_conn **ibconn)
491 struct iser_conn *ib_conn;
493 ib_conn = kzalloc(sizeof *ib_conn, GFP_KERNEL);
495 iser_err("can't alloc memory for struct iser_conn\n");
498 ib_conn->state = ISER_CONN_INIT;
499 init_waitqueue_head(&ib_conn->wait);
500 atomic_set(&ib_conn->post_recv_buf_count, 0);
501 atomic_set(&ib_conn->post_send_buf_count, 0);
502 INIT_LIST_HEAD(&ib_conn->conn_list);
503 spin_lock_init(&ib_conn->lock);
510 * starts the process of connecting to the target
511 * sleeps untill the connection is established or rejected
513 int iser_connect(struct iser_conn *ib_conn,
514 struct sockaddr_in *src_addr,
515 struct sockaddr_in *dst_addr,
518 struct sockaddr *src, *dst;
521 sprintf(ib_conn->name,"%d.%d.%d.%d:%d",
522 NIPQUAD(dst_addr->sin_addr.s_addr), dst_addr->sin_port);
524 /* the device is known only --after-- address resolution */
525 ib_conn->device = NULL;
527 iser_err("connecting to: %d.%d.%d.%d, port 0x%x\n",
528 NIPQUAD(dst_addr->sin_addr), dst_addr->sin_port);
530 ib_conn->state = ISER_CONN_PENDING;
532 ib_conn->cma_id = rdma_create_id(iser_cma_handler,
535 if (IS_ERR(ib_conn->cma_id)) {
536 err = PTR_ERR(ib_conn->cma_id);
537 iser_err("rdma_create_id failed: %d\n", err);
541 src = (struct sockaddr *)src_addr;
542 dst = (struct sockaddr *)dst_addr;
543 err = rdma_resolve_addr(ib_conn->cma_id, src, dst, 1000);
545 iser_err("rdma_resolve_addr failed: %d\n", err);
550 wait_event_interruptible(ib_conn->wait,
551 (ib_conn->state != ISER_CONN_PENDING));
553 if (ib_conn->state != ISER_CONN_UP) {
555 goto connect_failure;
559 mutex_lock(&ig.connlist_mutex);
560 list_add(&ib_conn->conn_list, &ig.connlist);
561 mutex_unlock(&ig.connlist_mutex);
565 ib_conn->cma_id = NULL;
567 ib_conn->state = ISER_CONN_DOWN;
569 iser_conn_release(ib_conn);
574 * iser_reg_page_vec - Register physical memory
576 * returns: 0 on success, errno code on failure
578 int iser_reg_page_vec(struct iser_conn *ib_conn,
579 struct iser_page_vec *page_vec,
580 struct iser_mem_reg *mem_reg)
582 struct ib_pool_fmr *mem;
587 page_list = page_vec->pages;
588 io_addr = page_list[0];
590 mem = ib_fmr_pool_map_phys(ib_conn->fmr_pool,
596 status = (int)PTR_ERR(mem);
597 iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
601 mem_reg->lkey = mem->fmr->lkey;
602 mem_reg->rkey = mem->fmr->rkey;
603 mem_reg->len = page_vec->length * SIZE_4K;
604 mem_reg->va = io_addr;
606 mem_reg->mem_h = (void *)mem;
608 mem_reg->va += page_vec->offset;
609 mem_reg->len = page_vec->data_size;
611 iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
612 "entry[0]: (0x%08lx,%ld)] -> "
613 "[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
614 page_vec, page_vec->length,
615 (unsigned long)page_vec->pages[0],
616 (unsigned long)page_vec->data_size,
617 (unsigned int)mem_reg->lkey, mem_reg->mem_h,
618 (unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
623 * Unregister (previosuly registered) memory.
625 void iser_unreg_mem(struct iser_mem_reg *reg)
629 iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
631 ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
633 iser_err("ib_fmr_pool_unmap failed %d\n", ret);
639 * iser_dto_to_iov - builds IOV from a dto descriptor
641 static void iser_dto_to_iov(struct iser_dto *dto, struct ib_sge *iov, int iov_len)
645 struct iser_regd_buf *regd_buf;
647 if (dto->regd_vector_len > iov_len) {
648 iser_err("iov size %d too small for posting dto of len %d\n",
649 iov_len, dto->regd_vector_len);
653 for (i = 0; i < dto->regd_vector_len; i++) {
655 regd_buf = dto->regd[i];
657 sge->addr = regd_buf->reg.va;
658 sge->length = regd_buf->reg.len;
659 sge->lkey = regd_buf->reg.lkey;
661 if (dto->used_sz[i] > 0) /* Adjust size */
662 sge->length = dto->used_sz[i];
664 /* offset and length should not exceed the regd buf length */
665 if (sge->length + dto->offset[i] > regd_buf->reg.len) {
666 iser_err("Used len:%ld + offset:%d, exceed reg.buf.len:"
667 "%ld in dto:0x%p [%d], va:0x%08lX\n",
668 (unsigned long)sge->length, dto->offset[i],
669 (unsigned long)regd_buf->reg.len, dto, i,
670 (unsigned long)sge->addr);
674 sge->addr += dto->offset[i]; /* Adjust offset */
679 * iser_post_recv - Posts a receive buffer.
681 * returns 0 on success, -1 on failure
683 int iser_post_recv(struct iser_desc *rx_desc)
685 int ib_ret, ret_val = 0;
686 struct ib_recv_wr recv_wr, *recv_wr_failed;
687 struct ib_sge iov[2];
688 struct iser_conn *ib_conn;
689 struct iser_dto *recv_dto = &rx_desc->dto;
692 ib_conn = recv_dto->ib_conn;
694 iser_dto_to_iov(recv_dto, iov, 2);
697 recv_wr.sg_list = iov;
698 recv_wr.num_sge = recv_dto->regd_vector_len;
699 recv_wr.wr_id = (unsigned long)rx_desc;
701 atomic_inc(&ib_conn->post_recv_buf_count);
702 ib_ret = ib_post_recv(ib_conn->qp, &recv_wr, &recv_wr_failed);
704 iser_err("ib_post_recv failed ret=%d\n", ib_ret);
705 atomic_dec(&ib_conn->post_recv_buf_count);
713 * iser_start_send - Initiate a Send DTO operation
715 * returns 0 on success, -1 on failure
717 int iser_post_send(struct iser_desc *tx_desc)
719 int ib_ret, ret_val = 0;
720 struct ib_send_wr send_wr, *send_wr_failed;
721 struct ib_sge iov[MAX_REGD_BUF_VECTOR_LEN];
722 struct iser_conn *ib_conn;
723 struct iser_dto *dto = &tx_desc->dto;
725 ib_conn = dto->ib_conn;
727 iser_dto_to_iov(dto, iov, MAX_REGD_BUF_VECTOR_LEN);
730 send_wr.wr_id = (unsigned long)tx_desc;
731 send_wr.sg_list = iov;
732 send_wr.num_sge = dto->regd_vector_len;
733 send_wr.opcode = IB_WR_SEND;
734 send_wr.send_flags = dto->notify_enable ? IB_SEND_SIGNALED : 0;
736 atomic_inc(&ib_conn->post_send_buf_count);
738 ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
740 iser_err("Failed to start SEND DTO, dto: 0x%p, IOV len: %d\n",
741 dto, dto->regd_vector_len);
742 iser_err("ib_post_send failed, ret:%d\n", ib_ret);
743 atomic_dec(&ib_conn->post_send_buf_count);
750 static void iser_handle_comp_error(struct iser_desc *desc)
752 struct iser_dto *dto = &desc->dto;
753 struct iser_conn *ib_conn = dto->ib_conn;
755 iser_dto_buffs_release(dto);
757 if (desc->type == ISCSI_RX) {
759 kmem_cache_free(ig.desc_cache, desc);
760 atomic_dec(&ib_conn->post_recv_buf_count);
761 } else { /* type is TX control/command/dataout */
762 if (desc->type == ISCSI_TX_DATAOUT)
763 kmem_cache_free(ig.desc_cache, desc);
764 atomic_dec(&ib_conn->post_send_buf_count);
767 if (atomic_read(&ib_conn->post_recv_buf_count) == 0 &&
768 atomic_read(&ib_conn->post_send_buf_count) == 0) {
769 /* getting here when the state is UP means that the conn is *
770 * being terminated asynchronously from the iSCSI layer's *
772 if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
773 ISER_CONN_TERMINATING))
774 iscsi_conn_failure(ib_conn->iser_conn->iscsi_conn,
775 ISCSI_ERR_CONN_FAILED);
777 /* complete the termination process if disconnect event was delivered *
778 * note there are no more non completed posts to the QP */
779 if (ib_conn->disc_evt_flag) {
780 ib_conn->state = ISER_CONN_DOWN;
781 wake_up_interruptible(&ib_conn->wait);
786 static void iser_cq_tasklet_fn(unsigned long data)
788 struct iser_device *device = (struct iser_device *)data;
789 struct ib_cq *cq = device->cq;
791 struct iser_desc *desc;
792 unsigned long xfer_len;
794 while (ib_poll_cq(cq, 1, &wc) == 1) {
795 desc = (struct iser_desc *) (unsigned long) wc.wr_id;
796 BUG_ON(desc == NULL);
798 if (wc.status == IB_WC_SUCCESS) {
799 if (desc->type == ISCSI_RX) {
800 xfer_len = (unsigned long)wc.byte_len;
801 iser_rcv_completion(desc, xfer_len);
802 } else /* type == ISCSI_TX_CONTROL/SCSI_CMD/DOUT */
803 iser_snd_completion(desc);
805 iser_err("comp w. error op %d status %d\n",desc->type,wc.status);
806 iser_handle_comp_error(desc);
809 /* #warning "it is assumed here that arming CQ only once its empty" *
810 * " would not cause interrupts to be missed" */
811 ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
814 static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
816 struct iser_device *device = (struct iser_device *)cq_context;
818 tasklet_schedule(&device->cq_tasklet);