iser_verbs.c revision 2c4ce609347f2a45792c8d9ebb5af11217766cb6
1/*
2 * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3 * Copyright (c) 2005, 2006 Cisco Systems.  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
9 * OpenIB.org BSD license below:
10 *
11 *     Redistribution and use in source and binary forms, with or
12 *     without modification, are permitted provided that the following
13 *     conditions are met:
14 *
15 *	- Redistributions of source code must retain the above
16 *	  copyright notice, this list of conditions and the following
17 *	  disclaimer.
18 *
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.
23 *
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
31 * SOFTWARE.
32 */
33#include <linux/kernel.h>
34#include <linux/module.h>
35#include <linux/slab.h>
36#include <linux/delay.h>
37
38#include "iscsi_iser.h"
39
40#define ISCSI_ISER_MAX_CONN	8
41#define ISER_MAX_RX_CQ_LEN	(ISER_QP_MAX_RECV_DTOS * ISCSI_ISER_MAX_CONN)
42#define ISER_MAX_TX_CQ_LEN	(ISER_QP_MAX_REQ_DTOS  * ISCSI_ISER_MAX_CONN)
43
44static void iser_cq_tasklet_fn(unsigned long data);
45static void iser_cq_callback(struct ib_cq *cq, void *cq_context);
46
47static void iser_cq_event_callback(struct ib_event *cause, void *context)
48{
49	iser_err("got cq event %d \n", cause->event);
50}
51
52static void iser_qp_event_callback(struct ib_event *cause, void *context)
53{
54	iser_err("got qp event %d\n",cause->event);
55}
56
57static void iser_event_handler(struct ib_event_handler *handler,
58				struct ib_event *event)
59{
60	iser_err("async event %d on device %s port %d\n", event->event,
61		event->device->name, event->element.port_num);
62}
63
64/**
65 * iser_create_device_ib_res - creates Protection Domain (PD), Completion
66 * Queue (CQ), DMA Memory Region (DMA MR) with the device associated with
67 * the adapator.
68 *
69 * returns 0 on success, -1 on failure
70 */
71static int iser_create_device_ib_res(struct iser_device *device)
72{
73	device->pd = ib_alloc_pd(device->ib_device);
74	if (IS_ERR(device->pd))
75		goto pd_err;
76
77	device->rx_cq = ib_create_cq(device->ib_device,
78				  iser_cq_callback,
79				  iser_cq_event_callback,
80				  (void *)device,
81				  ISER_MAX_RX_CQ_LEN, 0);
82	if (IS_ERR(device->rx_cq))
83		goto rx_cq_err;
84
85	device->tx_cq = ib_create_cq(device->ib_device,
86				  NULL, iser_cq_event_callback,
87				  (void *)device,
88				  ISER_MAX_TX_CQ_LEN, 0);
89
90	if (IS_ERR(device->tx_cq))
91		goto tx_cq_err;
92
93	if (ib_req_notify_cq(device->rx_cq, IB_CQ_NEXT_COMP))
94		goto cq_arm_err;
95
96	tasklet_init(&device->cq_tasklet,
97		     iser_cq_tasklet_fn,
98		     (unsigned long)device);
99
100	device->mr = ib_get_dma_mr(device->pd, IB_ACCESS_LOCAL_WRITE |
101				   IB_ACCESS_REMOTE_WRITE |
102				   IB_ACCESS_REMOTE_READ);
103	if (IS_ERR(device->mr))
104		goto dma_mr_err;
105
106	INIT_IB_EVENT_HANDLER(&device->event_handler, device->ib_device,
107				iser_event_handler);
108	if (ib_register_event_handler(&device->event_handler))
109		goto handler_err;
110
111	return 0;
112
113handler_err:
114	ib_dereg_mr(device->mr);
115dma_mr_err:
116	tasklet_kill(&device->cq_tasklet);
117cq_arm_err:
118	ib_destroy_cq(device->tx_cq);
119tx_cq_err:
120	ib_destroy_cq(device->rx_cq);
121rx_cq_err:
122	ib_dealloc_pd(device->pd);
123pd_err:
124	iser_err("failed to allocate an IB resource\n");
125	return -1;
126}
127
128/**
129 * iser_free_device_ib_res - destroy/dealloc/dereg the DMA MR,
130 * CQ and PD created with the device associated with the adapator.
131 */
132static void iser_free_device_ib_res(struct iser_device *device)
133{
134	BUG_ON(device->mr == NULL);
135
136	tasklet_kill(&device->cq_tasklet);
137	(void)ib_unregister_event_handler(&device->event_handler);
138	(void)ib_dereg_mr(device->mr);
139	(void)ib_destroy_cq(device->tx_cq);
140	(void)ib_destroy_cq(device->rx_cq);
141	(void)ib_dealloc_pd(device->pd);
142
143	device->mr = NULL;
144	device->tx_cq = NULL;
145	device->rx_cq = NULL;
146	device->pd = NULL;
147}
148
149/**
150 * iser_create_ib_conn_res - Creates FMR pool and Queue-Pair (QP)
151 *
152 * returns 0 on success, -1 on failure
153 */
154static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
155{
156	struct iser_device	*device;
157	struct ib_qp_init_attr	init_attr;
158	int			req_err, resp_err, ret = -ENOMEM;
159	struct ib_fmr_pool_param params;
160
161	BUG_ON(ib_conn->device == NULL);
162
163	device = ib_conn->device;
164
165	ib_conn->login_buf = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN +
166					ISER_RX_LOGIN_SIZE, GFP_KERNEL);
167	if (!ib_conn->login_buf)
168		goto out_err;
169
170	ib_conn->login_req_buf  = ib_conn->login_buf;
171	ib_conn->login_resp_buf = ib_conn->login_buf + ISCSI_DEF_MAX_RECV_SEG_LEN;
172
173	ib_conn->login_req_dma = ib_dma_map_single(ib_conn->device->ib_device,
174				(void *)ib_conn->login_req_buf,
175				ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
176
177	ib_conn->login_resp_dma = ib_dma_map_single(ib_conn->device->ib_device,
178				(void *)ib_conn->login_resp_buf,
179				ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
180
181	req_err  = ib_dma_mapping_error(device->ib_device, ib_conn->login_req_dma);
182	resp_err = ib_dma_mapping_error(device->ib_device, ib_conn->login_resp_dma);
183
184	if (req_err || resp_err) {
185		if (req_err)
186			ib_conn->login_req_dma = 0;
187		if (resp_err)
188			ib_conn->login_resp_dma = 0;
189		goto out_err;
190	}
191
192	ib_conn->page_vec = kmalloc(sizeof(struct iser_page_vec) +
193				    (sizeof(u64) * (ISCSI_ISER_SG_TABLESIZE +1)),
194				    GFP_KERNEL);
195	if (!ib_conn->page_vec)
196		goto out_err;
197
198	ib_conn->page_vec->pages = (u64 *) (ib_conn->page_vec + 1);
199
200	params.page_shift        = SHIFT_4K;
201	/* when the first/last SG element are not start/end *
202	 * page aligned, the map whould be of N+1 pages     */
203	params.max_pages_per_fmr = ISCSI_ISER_SG_TABLESIZE + 1;
204	/* make the pool size twice the max number of SCSI commands *
205	 * the ML is expected to queue, watermark for unmap at 50%  */
206	params.pool_size	 = ISCSI_DEF_XMIT_CMDS_MAX * 2;
207	params.dirty_watermark	 = ISCSI_DEF_XMIT_CMDS_MAX;
208	params.cache		 = 0;
209	params.flush_function	 = NULL;
210	params.access		 = (IB_ACCESS_LOCAL_WRITE  |
211				    IB_ACCESS_REMOTE_WRITE |
212				    IB_ACCESS_REMOTE_READ);
213
214	ib_conn->fmr_pool = ib_create_fmr_pool(device->pd, &params);
215	if (IS_ERR(ib_conn->fmr_pool)) {
216		ret = PTR_ERR(ib_conn->fmr_pool);
217		ib_conn->fmr_pool = NULL;
218		goto out_err;
219	}
220
221	memset(&init_attr, 0, sizeof init_attr);
222
223	init_attr.event_handler = iser_qp_event_callback;
224	init_attr.qp_context	= (void *)ib_conn;
225	init_attr.send_cq	= device->tx_cq;
226	init_attr.recv_cq	= device->rx_cq;
227	init_attr.cap.max_send_wr  = ISER_QP_MAX_REQ_DTOS;
228	init_attr.cap.max_recv_wr  = ISER_QP_MAX_RECV_DTOS;
229	init_attr.cap.max_send_sge = 2;
230	init_attr.cap.max_recv_sge = 1;
231	init_attr.sq_sig_type	= IB_SIGNAL_REQ_WR;
232	init_attr.qp_type	= IB_QPT_RC;
233
234	ret = rdma_create_qp(ib_conn->cma_id, device->pd, &init_attr);
235	if (ret)
236		goto out_err;
237
238	ib_conn->qp = ib_conn->cma_id->qp;
239	iser_err("setting conn %p cma_id %p: fmr_pool %p qp %p\n",
240		 ib_conn, ib_conn->cma_id,
241		 ib_conn->fmr_pool, ib_conn->cma_id->qp);
242	return ret;
243
244out_err:
245	iser_err("unable to alloc mem or create resource, err %d\n", ret);
246	return ret;
247}
248
249/**
250 * releases the FMR pool, QP and CMA ID objects, returns 0 on success,
251 * -1 on failure
252 */
253static int iser_free_ib_conn_res(struct iser_conn *ib_conn, int can_destroy_id)
254{
255	BUG_ON(ib_conn == NULL);
256
257	iser_err("freeing conn %p cma_id %p fmr pool %p qp %p\n",
258		 ib_conn, ib_conn->cma_id,
259		 ib_conn->fmr_pool, ib_conn->qp);
260
261	/* qp is created only once both addr & route are resolved */
262	if (ib_conn->fmr_pool != NULL)
263		ib_destroy_fmr_pool(ib_conn->fmr_pool);
264
265	if (ib_conn->qp != NULL)
266		rdma_destroy_qp(ib_conn->cma_id);
267
268	/* if cma handler context, the caller acts s.t the cma destroy the id */
269	if (ib_conn->cma_id != NULL && can_destroy_id)
270		rdma_destroy_id(ib_conn->cma_id);
271
272	ib_conn->fmr_pool = NULL;
273	ib_conn->qp	  = NULL;
274	ib_conn->cma_id   = NULL;
275	kfree(ib_conn->page_vec);
276
277	return 0;
278}
279
280/**
281 * based on the resolved device node GUID see if there already allocated
282 * device for this device. If there's no such, create one.
283 */
284static
285struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
286{
287	struct iser_device *device;
288
289	mutex_lock(&ig.device_list_mutex);
290
291	list_for_each_entry(device, &ig.device_list, ig_list)
292		/* find if there's a match using the node GUID */
293		if (device->ib_device->node_guid == cma_id->device->node_guid)
294			goto inc_refcnt;
295
296	device = kzalloc(sizeof *device, GFP_KERNEL);
297	if (device == NULL)
298		goto out;
299
300	/* assign this device to the device */
301	device->ib_device = cma_id->device;
302	/* init the device and link it into ig device list */
303	if (iser_create_device_ib_res(device)) {
304		kfree(device);
305		device = NULL;
306		goto out;
307	}
308	list_add(&device->ig_list, &ig.device_list);
309
310inc_refcnt:
311	device->refcount++;
312out:
313	mutex_unlock(&ig.device_list_mutex);
314	return device;
315}
316
317/* if there's no demand for this device, release it */
318static void iser_device_try_release(struct iser_device *device)
319{
320	mutex_lock(&ig.device_list_mutex);
321	device->refcount--;
322	iser_err("device %p refcount %d\n",device,device->refcount);
323	if (!device->refcount) {
324		iser_free_device_ib_res(device);
325		list_del(&device->ig_list);
326		kfree(device);
327	}
328	mutex_unlock(&ig.device_list_mutex);
329}
330
331static int iser_conn_state_comp_exch(struct iser_conn *ib_conn,
332				     enum iser_ib_conn_state comp,
333				     enum iser_ib_conn_state exch)
334{
335	int ret;
336
337	spin_lock_bh(&ib_conn->lock);
338	if ((ret = (ib_conn->state == comp)))
339		ib_conn->state = exch;
340	spin_unlock_bh(&ib_conn->lock);
341	return ret;
342}
343
344/**
345 * Frees all conn objects and deallocs conn descriptor
346 */
347static void iser_conn_release(struct iser_conn *ib_conn, int can_destroy_id)
348{
349	struct iser_device  *device = ib_conn->device;
350
351	BUG_ON(ib_conn->state != ISER_CONN_DOWN);
352
353	mutex_lock(&ig.connlist_mutex);
354	list_del(&ib_conn->conn_list);
355	mutex_unlock(&ig.connlist_mutex);
356	iser_free_rx_descriptors(ib_conn);
357	iser_free_ib_conn_res(ib_conn, can_destroy_id);
358	ib_conn->device = NULL;
359	/* on EVENT_ADDR_ERROR there's no device yet for this conn */
360	if (device != NULL)
361		iser_device_try_release(device);
362	iscsi_destroy_endpoint(ib_conn->ep);
363}
364
365void iser_conn_get(struct iser_conn *ib_conn)
366{
367	atomic_inc(&ib_conn->refcount);
368}
369
370int iser_conn_put(struct iser_conn *ib_conn, int can_destroy_id)
371{
372	if (atomic_dec_and_test(&ib_conn->refcount)) {
373		iser_conn_release(ib_conn, can_destroy_id);
374		return 1;
375	}
376	return 0;
377}
378
379/**
380 * triggers start of the disconnect procedures and wait for them to be done
381 */
382void iser_conn_terminate(struct iser_conn *ib_conn)
383{
384	int err = 0;
385
386	/* change the ib conn state only if the conn is UP, however always call
387	 * rdma_disconnect since this is the only way to cause the CMA to change
388	 * the QP state to ERROR
389	 */
390
391	iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP, ISER_CONN_TERMINATING);
392	err = rdma_disconnect(ib_conn->cma_id);
393	if (err)
394		iser_err("Failed to disconnect, conn: 0x%p err %d\n",
395			 ib_conn,err);
396
397	wait_event_interruptible(ib_conn->wait,
398				 ib_conn->state == ISER_CONN_DOWN);
399
400	iser_conn_put(ib_conn, 1); /* deref ib conn deallocate */
401}
402
403static int iser_connect_error(struct rdma_cm_id *cma_id)
404{
405	struct iser_conn *ib_conn;
406	ib_conn = (struct iser_conn *)cma_id->context;
407
408	ib_conn->state = ISER_CONN_DOWN;
409	wake_up_interruptible(&ib_conn->wait);
410	return iser_conn_put(ib_conn, 0); /* deref ib conn's cma id */
411}
412
413static int iser_addr_handler(struct rdma_cm_id *cma_id)
414{
415	struct iser_device *device;
416	struct iser_conn   *ib_conn;
417	int    ret;
418
419	device = iser_device_find_by_ib_device(cma_id);
420	if (!device) {
421		iser_err("device lookup/creation failed\n");
422		return iser_connect_error(cma_id);
423	}
424
425	ib_conn = (struct iser_conn *)cma_id->context;
426	ib_conn->device = device;
427
428	ret = rdma_resolve_route(cma_id, 1000);
429	if (ret) {
430		iser_err("resolve route failed: %d\n", ret);
431		return iser_connect_error(cma_id);
432	}
433
434	return 0;
435}
436
437static int iser_route_handler(struct rdma_cm_id *cma_id)
438{
439	struct rdma_conn_param conn_param;
440	int    ret;
441
442	ret = iser_create_ib_conn_res((struct iser_conn *)cma_id->context);
443	if (ret)
444		goto failure;
445
446	memset(&conn_param, 0, sizeof conn_param);
447	conn_param.responder_resources = 4;
448	conn_param.initiator_depth     = 1;
449	conn_param.retry_count	       = 7;
450	conn_param.rnr_retry_count     = 6;
451
452	ret = rdma_connect(cma_id, &conn_param);
453	if (ret) {
454		iser_err("failure connecting: %d\n", ret);
455		goto failure;
456	}
457
458	return 0;
459failure:
460	return iser_connect_error(cma_id);
461}
462
463static void iser_connected_handler(struct rdma_cm_id *cma_id)
464{
465	struct iser_conn *ib_conn;
466
467	ib_conn = (struct iser_conn *)cma_id->context;
468	ib_conn->state = ISER_CONN_UP;
469	wake_up_interruptible(&ib_conn->wait);
470}
471
472static int iser_disconnected_handler(struct rdma_cm_id *cma_id)
473{
474	struct iser_conn *ib_conn;
475	int ret;
476
477	ib_conn = (struct iser_conn *)cma_id->context;
478
479	/* getting here when the state is UP means that the conn is being *
480	 * terminated asynchronously from the iSCSI layer's perspective.  */
481	if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
482				      ISER_CONN_TERMINATING))
483		iscsi_conn_failure(ib_conn->iser_conn->iscsi_conn,
484				   ISCSI_ERR_CONN_FAILED);
485
486	/* Complete the termination process if no posts are pending */
487	if (ib_conn->post_recv_buf_count == 0 &&
488	    (atomic_read(&ib_conn->post_send_buf_count) == 0)) {
489		ib_conn->state = ISER_CONN_DOWN;
490		wake_up_interruptible(&ib_conn->wait);
491	}
492
493	ret = iser_conn_put(ib_conn, 0); /* deref ib conn's cma id */
494	return ret;
495}
496
497static int iser_cma_handler(struct rdma_cm_id *cma_id, struct rdma_cm_event *event)
498{
499	int ret = 0;
500
501	iser_err("event %d status %d conn %p id %p\n",
502		event->event, event->status, cma_id->context, cma_id);
503
504	switch (event->event) {
505	case RDMA_CM_EVENT_ADDR_RESOLVED:
506		ret = iser_addr_handler(cma_id);
507		break;
508	case RDMA_CM_EVENT_ROUTE_RESOLVED:
509		ret = iser_route_handler(cma_id);
510		break;
511	case RDMA_CM_EVENT_ESTABLISHED:
512		iser_connected_handler(cma_id);
513		break;
514	case RDMA_CM_EVENT_ADDR_ERROR:
515	case RDMA_CM_EVENT_ROUTE_ERROR:
516	case RDMA_CM_EVENT_CONNECT_ERROR:
517	case RDMA_CM_EVENT_UNREACHABLE:
518	case RDMA_CM_EVENT_REJECTED:
519		ret = iser_connect_error(cma_id);
520		break;
521	case RDMA_CM_EVENT_DISCONNECTED:
522	case RDMA_CM_EVENT_DEVICE_REMOVAL:
523	case RDMA_CM_EVENT_ADDR_CHANGE:
524		ret = iser_disconnected_handler(cma_id);
525		break;
526	default:
527		iser_err("Unexpected RDMA CM event (%d)\n", event->event);
528		break;
529	}
530	return ret;
531}
532
533void iser_conn_init(struct iser_conn *ib_conn)
534{
535	ib_conn->state = ISER_CONN_INIT;
536	init_waitqueue_head(&ib_conn->wait);
537	ib_conn->post_recv_buf_count = 0;
538	atomic_set(&ib_conn->post_send_buf_count, 0);
539	atomic_set(&ib_conn->refcount, 1); /* ref ib conn allocation */
540	INIT_LIST_HEAD(&ib_conn->conn_list);
541	spin_lock_init(&ib_conn->lock);
542}
543
544 /**
545 * starts the process of connecting to the target
546 * sleeps until the connection is established or rejected
547 */
548int iser_connect(struct iser_conn   *ib_conn,
549		 struct sockaddr_in *src_addr,
550		 struct sockaddr_in *dst_addr,
551		 int                 non_blocking)
552{
553	struct sockaddr *src, *dst;
554	int err = 0;
555
556	sprintf(ib_conn->name, "%pI4:%d",
557		&dst_addr->sin_addr.s_addr, dst_addr->sin_port);
558
559	/* the device is known only --after-- address resolution */
560	ib_conn->device = NULL;
561
562	iser_err("connecting to: %pI4, port 0x%x\n",
563		 &dst_addr->sin_addr, dst_addr->sin_port);
564
565	ib_conn->state = ISER_CONN_PENDING;
566
567	iser_conn_get(ib_conn); /* ref ib conn's cma id */
568	ib_conn->cma_id = rdma_create_id(iser_cma_handler,
569					     (void *)ib_conn,
570					     RDMA_PS_TCP, IB_QPT_RC);
571	if (IS_ERR(ib_conn->cma_id)) {
572		err = PTR_ERR(ib_conn->cma_id);
573		iser_err("rdma_create_id failed: %d\n", err);
574		goto id_failure;
575	}
576
577	src = (struct sockaddr *)src_addr;
578	dst = (struct sockaddr *)dst_addr;
579	err = rdma_resolve_addr(ib_conn->cma_id, src, dst, 1000);
580	if (err) {
581		iser_err("rdma_resolve_addr failed: %d\n", err);
582		goto addr_failure;
583	}
584
585	if (!non_blocking) {
586		wait_event_interruptible(ib_conn->wait,
587					 (ib_conn->state != ISER_CONN_PENDING));
588
589		if (ib_conn->state != ISER_CONN_UP) {
590			err =  -EIO;
591			goto connect_failure;
592		}
593	}
594
595	mutex_lock(&ig.connlist_mutex);
596	list_add(&ib_conn->conn_list, &ig.connlist);
597	mutex_unlock(&ig.connlist_mutex);
598	return 0;
599
600id_failure:
601	ib_conn->cma_id = NULL;
602addr_failure:
603	ib_conn->state = ISER_CONN_DOWN;
604connect_failure:
605	iser_conn_release(ib_conn, 1);
606	return err;
607}
608
609/**
610 * iser_reg_page_vec - Register physical memory
611 *
612 * returns: 0 on success, errno code on failure
613 */
614int iser_reg_page_vec(struct iser_conn     *ib_conn,
615		      struct iser_page_vec *page_vec,
616		      struct iser_mem_reg  *mem_reg)
617{
618	struct ib_pool_fmr *mem;
619	u64		   io_addr;
620	u64		   *page_list;
621	int		   status;
622
623	page_list = page_vec->pages;
624	io_addr	  = page_list[0];
625
626	mem  = ib_fmr_pool_map_phys(ib_conn->fmr_pool,
627				    page_list,
628				    page_vec->length,
629				    io_addr);
630
631	if (IS_ERR(mem)) {
632		status = (int)PTR_ERR(mem);
633		iser_err("ib_fmr_pool_map_phys failed: %d\n", status);
634		return status;
635	}
636
637	mem_reg->lkey  = mem->fmr->lkey;
638	mem_reg->rkey  = mem->fmr->rkey;
639	mem_reg->len   = page_vec->length * SIZE_4K;
640	mem_reg->va    = io_addr;
641	mem_reg->is_fmr = 1;
642	mem_reg->mem_h = (void *)mem;
643
644	mem_reg->va   += page_vec->offset;
645	mem_reg->len   = page_vec->data_size;
646
647	iser_dbg("PHYSICAL Mem.register, [PHYS p_array: 0x%p, sz: %d, "
648		 "entry[0]: (0x%08lx,%ld)] -> "
649		 "[lkey: 0x%08X mem_h: 0x%p va: 0x%08lX sz: %ld]\n",
650		 page_vec, page_vec->length,
651		 (unsigned long)page_vec->pages[0],
652		 (unsigned long)page_vec->data_size,
653		 (unsigned int)mem_reg->lkey, mem_reg->mem_h,
654		 (unsigned long)mem_reg->va, (unsigned long)mem_reg->len);
655	return 0;
656}
657
658/**
659 * Unregister (previosuly registered) memory.
660 */
661void iser_unreg_mem(struct iser_mem_reg *reg)
662{
663	int ret;
664
665	iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
666
667	ret = ib_fmr_pool_unmap((struct ib_pool_fmr *)reg->mem_h);
668	if (ret)
669		iser_err("ib_fmr_pool_unmap failed %d\n", ret);
670
671	reg->mem_h = NULL;
672}
673
674int iser_post_recvl(struct iser_conn *ib_conn)
675{
676	struct ib_recv_wr rx_wr, *rx_wr_failed;
677	struct ib_sge	  sge;
678	int ib_ret;
679
680	sge.addr   = ib_conn->login_resp_dma;
681	sge.length = ISER_RX_LOGIN_SIZE;
682	sge.lkey   = ib_conn->device->mr->lkey;
683
684	rx_wr.wr_id   = (unsigned long)ib_conn->login_resp_buf;
685	rx_wr.sg_list = &sge;
686	rx_wr.num_sge = 1;
687	rx_wr.next    = NULL;
688
689	ib_conn->post_recv_buf_count++;
690	ib_ret	= ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
691	if (ib_ret) {
692		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
693		ib_conn->post_recv_buf_count--;
694	}
695	return ib_ret;
696}
697
698int iser_post_recvm(struct iser_conn *ib_conn, int count)
699{
700	struct ib_recv_wr *rx_wr, *rx_wr_failed;
701	int i, ib_ret;
702	unsigned int my_rx_head = ib_conn->rx_desc_head;
703	struct iser_rx_desc *rx_desc;
704
705	for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
706		rx_desc		= &ib_conn->rx_descs[my_rx_head];
707		rx_wr->wr_id	= (unsigned long)rx_desc;
708		rx_wr->sg_list	= &rx_desc->rx_sg;
709		rx_wr->num_sge	= 1;
710		rx_wr->next	= rx_wr + 1;
711		my_rx_head = (my_rx_head + 1) & (ISER_QP_MAX_RECV_DTOS - 1);
712	}
713
714	rx_wr--;
715	rx_wr->next = NULL; /* mark end of work requests list */
716
717	ib_conn->post_recv_buf_count += count;
718	ib_ret	= ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
719	if (ib_ret) {
720		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
721		ib_conn->post_recv_buf_count -= count;
722	} else
723		ib_conn->rx_desc_head = my_rx_head;
724	return ib_ret;
725}
726
727
728/**
729 * iser_start_send - Initiate a Send DTO operation
730 *
731 * returns 0 on success, -1 on failure
732 */
733int iser_post_send(struct iser_conn *ib_conn, struct iser_tx_desc *tx_desc)
734{
735	int		  ib_ret;
736	struct ib_send_wr send_wr, *send_wr_failed;
737
738	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
739		tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
740
741	send_wr.next	   = NULL;
742	send_wr.wr_id	   = (unsigned long)tx_desc;
743	send_wr.sg_list	   = tx_desc->tx_sg;
744	send_wr.num_sge	   = tx_desc->num_sge;
745	send_wr.opcode	   = IB_WR_SEND;
746	send_wr.send_flags = IB_SEND_SIGNALED;
747
748	atomic_inc(&ib_conn->post_send_buf_count);
749
750	ib_ret = ib_post_send(ib_conn->qp, &send_wr, &send_wr_failed);
751	if (ib_ret) {
752		iser_err("ib_post_send failed, ret:%d\n", ib_ret);
753		atomic_dec(&ib_conn->post_send_buf_count);
754	}
755	return ib_ret;
756}
757
758static void iser_handle_comp_error(struct iser_tx_desc *desc,
759				struct iser_conn *ib_conn)
760{
761	if (desc && desc->type == ISCSI_TX_DATAOUT)
762		kmem_cache_free(ig.desc_cache, desc);
763
764	if (ib_conn->post_recv_buf_count == 0 &&
765	    atomic_read(&ib_conn->post_send_buf_count) == 0) {
766		/* getting here when the state is UP means that the conn is *
767		 * being terminated asynchronously from the iSCSI layer's   *
768		 * perspective.                                             */
769		if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
770		    ISER_CONN_TERMINATING))
771			iscsi_conn_failure(ib_conn->iser_conn->iscsi_conn,
772					   ISCSI_ERR_CONN_FAILED);
773
774		/* no more non completed posts to the QP, complete the
775		 * termination process w.o worrying on disconnect event */
776		ib_conn->state = ISER_CONN_DOWN;
777		wake_up_interruptible(&ib_conn->wait);
778	}
779}
780
781static int iser_drain_tx_cq(struct iser_device  *device)
782{
783	struct ib_cq  *cq = device->tx_cq;
784	struct ib_wc  wc;
785	struct iser_tx_desc *tx_desc;
786	struct iser_conn *ib_conn;
787	int completed_tx = 0;
788
789	while (ib_poll_cq(cq, 1, &wc) == 1) {
790		tx_desc	= (struct iser_tx_desc *) (unsigned long) wc.wr_id;
791		ib_conn = wc.qp->qp_context;
792		if (wc.status == IB_WC_SUCCESS) {
793			if (wc.opcode == IB_WC_SEND)
794				iser_snd_completion(tx_desc, ib_conn);
795			else
796				iser_err("expected opcode %d got %d\n",
797					IB_WC_SEND, wc.opcode);
798		} else {
799			iser_err("tx id %llx status %d vend_err %x\n",
800				wc.wr_id, wc.status, wc.vendor_err);
801			atomic_dec(&ib_conn->post_send_buf_count);
802			iser_handle_comp_error(tx_desc, ib_conn);
803		}
804		completed_tx++;
805	}
806	return completed_tx;
807}
808
809
810static void iser_cq_tasklet_fn(unsigned long data)
811{
812	 struct iser_device  *device = (struct iser_device *)data;
813	 struct ib_cq	     *cq = device->rx_cq;
814	 struct ib_wc	     wc;
815	 struct iser_rx_desc *desc;
816	 unsigned long	     xfer_len;
817	struct iser_conn *ib_conn;
818	int completed_tx, completed_rx;
819	completed_tx = completed_rx = 0;
820
821	while (ib_poll_cq(cq, 1, &wc) == 1) {
822		desc	 = (struct iser_rx_desc *) (unsigned long) wc.wr_id;
823		BUG_ON(desc == NULL);
824		ib_conn = wc.qp->qp_context;
825		if (wc.status == IB_WC_SUCCESS) {
826			if (wc.opcode == IB_WC_RECV) {
827				xfer_len = (unsigned long)wc.byte_len;
828				iser_rcv_completion(desc, xfer_len, ib_conn);
829			} else
830				iser_err("expected opcode %d got %d\n",
831					IB_WC_RECV, wc.opcode);
832		} else {
833			if (wc.status != IB_WC_WR_FLUSH_ERR)
834				iser_err("rx id %llx status %d vend_err %x\n",
835					wc.wr_id, wc.status, wc.vendor_err);
836			ib_conn->post_recv_buf_count--;
837			iser_handle_comp_error(NULL, ib_conn);
838		}
839		completed_rx++;
840		if (!(completed_rx & 63))
841			completed_tx += iser_drain_tx_cq(device);
842	}
843	/* #warning "it is assumed here that arming CQ only once its empty" *
844	 * " would not cause interrupts to be missed"                       */
845	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
846
847	completed_tx += iser_drain_tx_cq(device);
848	iser_dbg("got %d rx %d tx completions\n", completed_rx, completed_tx);
849}
850
851static void iser_cq_callback(struct ib_cq *cq, void *cq_context)
852{
853	struct iser_device  *device = (struct iser_device *)cq_context;
854
855	tasklet_schedule(&device->cq_tasklet);
856}
857