xref: /linux/drivers/infiniband/ulp/srpt/ib_srpt.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
1 /*
2  * Copyright (c) 2006 - 2009 Mellanox Technology Inc.  All rights reserved.
3  * Copyright (C) 2008 - 2011 Bart Van Assche <bvanassche@acm.org>.
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  */
34 
35 #include <linux/module.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/err.h>
39 #include <linux/ctype.h>
40 #include <linux/kthread.h>
41 #include <linux/string.h>
42 #include <linux/delay.h>
43 #include <linux/atomic.h>
44 #include <scsi/scsi_tcq.h>
45 #include <target/configfs_macros.h>
46 #include <target/target_core_base.h>
47 #include <target/target_core_fabric_configfs.h>
48 #include <target/target_core_fabric.h>
49 #include <target/target_core_configfs.h>
50 #include "ib_srpt.h"
51 
52 /* Name of this kernel module. */
53 #define DRV_NAME		"ib_srpt"
54 #define DRV_VERSION		"2.0.0"
55 #define DRV_RELDATE		"2011-02-14"
56 
57 #define SRPT_ID_STRING	"Linux SRP target"
58 
59 #undef pr_fmt
60 #define pr_fmt(fmt) DRV_NAME " " fmt
61 
62 MODULE_AUTHOR("Vu Pham and Bart Van Assche");
63 MODULE_DESCRIPTION("InfiniBand SCSI RDMA Protocol target "
64 		   "v" DRV_VERSION " (" DRV_RELDATE ")");
65 MODULE_LICENSE("Dual BSD/GPL");
66 
67 /*
68  * Global Variables
69  */
70 
71 static u64 srpt_service_guid;
72 static DEFINE_SPINLOCK(srpt_dev_lock);	/* Protects srpt_dev_list. */
73 static LIST_HEAD(srpt_dev_list);	/* List of srpt_device structures. */
74 
75 static unsigned srp_max_req_size = DEFAULT_MAX_REQ_SIZE;
76 module_param(srp_max_req_size, int, 0444);
77 MODULE_PARM_DESC(srp_max_req_size,
78 		 "Maximum size of SRP request messages in bytes.");
79 
80 static int srpt_srq_size = DEFAULT_SRPT_SRQ_SIZE;
81 module_param(srpt_srq_size, int, 0444);
82 MODULE_PARM_DESC(srpt_srq_size,
83 		 "Shared receive queue (SRQ) size.");
84 
85 static int srpt_get_u64_x(char *buffer, struct kernel_param *kp)
86 {
87 	return sprintf(buffer, "0x%016llx", *(u64 *)kp->arg);
88 }
89 module_param_call(srpt_service_guid, NULL, srpt_get_u64_x, &srpt_service_guid,
90 		  0444);
91 MODULE_PARM_DESC(srpt_service_guid,
92 		 "Using this value for ioc_guid, id_ext, and cm_listen_id"
93 		 " instead of using the node_guid of the first HCA.");
94 
95 static struct ib_client srpt_client;
96 static struct target_fabric_configfs *srpt_target;
97 static void srpt_release_channel(struct srpt_rdma_ch *ch);
98 static int srpt_queue_status(struct se_cmd *cmd);
99 
100 /**
101  * opposite_dma_dir() - Swap DMA_TO_DEVICE and DMA_FROM_DEVICE.
102  */
103 static inline
104 enum dma_data_direction opposite_dma_dir(enum dma_data_direction dir)
105 {
106 	switch (dir) {
107 	case DMA_TO_DEVICE:	return DMA_FROM_DEVICE;
108 	case DMA_FROM_DEVICE:	return DMA_TO_DEVICE;
109 	default:		return dir;
110 	}
111 }
112 
113 /**
114  * srpt_sdev_name() - Return the name associated with the HCA.
115  *
116  * Examples are ib0, ib1, ...
117  */
118 static inline const char *srpt_sdev_name(struct srpt_device *sdev)
119 {
120 	return sdev->device->name;
121 }
122 
123 static enum rdma_ch_state srpt_get_ch_state(struct srpt_rdma_ch *ch)
124 {
125 	unsigned long flags;
126 	enum rdma_ch_state state;
127 
128 	spin_lock_irqsave(&ch->spinlock, flags);
129 	state = ch->state;
130 	spin_unlock_irqrestore(&ch->spinlock, flags);
131 	return state;
132 }
133 
134 static enum rdma_ch_state
135 srpt_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state new_state)
136 {
137 	unsigned long flags;
138 	enum rdma_ch_state prev;
139 
140 	spin_lock_irqsave(&ch->spinlock, flags);
141 	prev = ch->state;
142 	ch->state = new_state;
143 	spin_unlock_irqrestore(&ch->spinlock, flags);
144 	return prev;
145 }
146 
147 /**
148  * srpt_test_and_set_ch_state() - Test and set the channel state.
149  *
150  * Returns true if and only if the channel state has been set to the new state.
151  */
152 static bool
153 srpt_test_and_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state old,
154 			   enum rdma_ch_state new)
155 {
156 	unsigned long flags;
157 	enum rdma_ch_state prev;
158 
159 	spin_lock_irqsave(&ch->spinlock, flags);
160 	prev = ch->state;
161 	if (prev == old)
162 		ch->state = new;
163 	spin_unlock_irqrestore(&ch->spinlock, flags);
164 	return prev == old;
165 }
166 
167 /**
168  * srpt_event_handler() - Asynchronous IB event callback function.
169  *
170  * Callback function called by the InfiniBand core when an asynchronous IB
171  * event occurs. This callback may occur in interrupt context. See also
172  * section 11.5.2, Set Asynchronous Event Handler in the InfiniBand
173  * Architecture Specification.
174  */
175 static void srpt_event_handler(struct ib_event_handler *handler,
176 			       struct ib_event *event)
177 {
178 	struct srpt_device *sdev;
179 	struct srpt_port *sport;
180 
181 	sdev = ib_get_client_data(event->device, &srpt_client);
182 	if (!sdev || sdev->device != event->device)
183 		return;
184 
185 	pr_debug("ASYNC event= %d on device= %s\n", event->event,
186 		 srpt_sdev_name(sdev));
187 
188 	switch (event->event) {
189 	case IB_EVENT_PORT_ERR:
190 		if (event->element.port_num <= sdev->device->phys_port_cnt) {
191 			sport = &sdev->port[event->element.port_num - 1];
192 			sport->lid = 0;
193 			sport->sm_lid = 0;
194 		}
195 		break;
196 	case IB_EVENT_PORT_ACTIVE:
197 	case IB_EVENT_LID_CHANGE:
198 	case IB_EVENT_PKEY_CHANGE:
199 	case IB_EVENT_SM_CHANGE:
200 	case IB_EVENT_CLIENT_REREGISTER:
201 		/* Refresh port data asynchronously. */
202 		if (event->element.port_num <= sdev->device->phys_port_cnt) {
203 			sport = &sdev->port[event->element.port_num - 1];
204 			if (!sport->lid && !sport->sm_lid)
205 				schedule_work(&sport->work);
206 		}
207 		break;
208 	default:
209 		printk(KERN_ERR "received unrecognized IB event %d\n",
210 		       event->event);
211 		break;
212 	}
213 }
214 
215 /**
216  * srpt_srq_event() - SRQ event callback function.
217  */
218 static void srpt_srq_event(struct ib_event *event, void *ctx)
219 {
220 	printk(KERN_INFO "SRQ event %d\n", event->event);
221 }
222 
223 /**
224  * srpt_qp_event() - QP event callback function.
225  */
226 static void srpt_qp_event(struct ib_event *event, struct srpt_rdma_ch *ch)
227 {
228 	pr_debug("QP event %d on cm_id=%p sess_name=%s state=%d\n",
229 		 event->event, ch->cm_id, ch->sess_name, srpt_get_ch_state(ch));
230 
231 	switch (event->event) {
232 	case IB_EVENT_COMM_EST:
233 		ib_cm_notify(ch->cm_id, event->event);
234 		break;
235 	case IB_EVENT_QP_LAST_WQE_REACHED:
236 		if (srpt_test_and_set_ch_state(ch, CH_DRAINING,
237 					       CH_RELEASING))
238 			srpt_release_channel(ch);
239 		else
240 			pr_debug("%s: state %d - ignored LAST_WQE.\n",
241 				 ch->sess_name, srpt_get_ch_state(ch));
242 		break;
243 	default:
244 		printk(KERN_ERR "received unrecognized IB QP event %d\n",
245 		       event->event);
246 		break;
247 	}
248 }
249 
250 /**
251  * srpt_set_ioc() - Helper function for initializing an IOUnitInfo structure.
252  *
253  * @slot: one-based slot number.
254  * @value: four-bit value.
255  *
256  * Copies the lowest four bits of value in element slot of the array of four
257  * bit elements called c_list (controller list). The index slot is one-based.
258  */
259 static void srpt_set_ioc(u8 *c_list, u32 slot, u8 value)
260 {
261 	u16 id;
262 	u8 tmp;
263 
264 	id = (slot - 1) / 2;
265 	if (slot & 0x1) {
266 		tmp = c_list[id] & 0xf;
267 		c_list[id] = (value << 4) | tmp;
268 	} else {
269 		tmp = c_list[id] & 0xf0;
270 		c_list[id] = (value & 0xf) | tmp;
271 	}
272 }
273 
274 /**
275  * srpt_get_class_port_info() - Copy ClassPortInfo to a management datagram.
276  *
277  * See also section 16.3.3.1 ClassPortInfo in the InfiniBand Architecture
278  * Specification.
279  */
280 static void srpt_get_class_port_info(struct ib_dm_mad *mad)
281 {
282 	struct ib_class_port_info *cif;
283 
284 	cif = (struct ib_class_port_info *)mad->data;
285 	memset(cif, 0, sizeof *cif);
286 	cif->base_version = 1;
287 	cif->class_version = 1;
288 	cif->resp_time_value = 20;
289 
290 	mad->mad_hdr.status = 0;
291 }
292 
293 /**
294  * srpt_get_iou() - Write IOUnitInfo to a management datagram.
295  *
296  * See also section 16.3.3.3 IOUnitInfo in the InfiniBand Architecture
297  * Specification. See also section B.7, table B.6 in the SRP r16a document.
298  */
299 static void srpt_get_iou(struct ib_dm_mad *mad)
300 {
301 	struct ib_dm_iou_info *ioui;
302 	u8 slot;
303 	int i;
304 
305 	ioui = (struct ib_dm_iou_info *)mad->data;
306 	ioui->change_id = __constant_cpu_to_be16(1);
307 	ioui->max_controllers = 16;
308 
309 	/* set present for slot 1 and empty for the rest */
310 	srpt_set_ioc(ioui->controller_list, 1, 1);
311 	for (i = 1, slot = 2; i < 16; i++, slot++)
312 		srpt_set_ioc(ioui->controller_list, slot, 0);
313 
314 	mad->mad_hdr.status = 0;
315 }
316 
317 /**
318  * srpt_get_ioc() - Write IOControllerprofile to a management datagram.
319  *
320  * See also section 16.3.3.4 IOControllerProfile in the InfiniBand
321  * Architecture Specification. See also section B.7, table B.7 in the SRP
322  * r16a document.
323  */
324 static void srpt_get_ioc(struct srpt_port *sport, u32 slot,
325 			 struct ib_dm_mad *mad)
326 {
327 	struct srpt_device *sdev = sport->sdev;
328 	struct ib_dm_ioc_profile *iocp;
329 
330 	iocp = (struct ib_dm_ioc_profile *)mad->data;
331 
332 	if (!slot || slot > 16) {
333 		mad->mad_hdr.status
334 			= __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
335 		return;
336 	}
337 
338 	if (slot > 2) {
339 		mad->mad_hdr.status
340 			= __constant_cpu_to_be16(DM_MAD_STATUS_NO_IOC);
341 		return;
342 	}
343 
344 	memset(iocp, 0, sizeof *iocp);
345 	strcpy(iocp->id_string, SRPT_ID_STRING);
346 	iocp->guid = cpu_to_be64(srpt_service_guid);
347 	iocp->vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
348 	iocp->device_id = cpu_to_be32(sdev->dev_attr.vendor_part_id);
349 	iocp->device_version = cpu_to_be16(sdev->dev_attr.hw_ver);
350 	iocp->subsys_vendor_id = cpu_to_be32(sdev->dev_attr.vendor_id);
351 	iocp->subsys_device_id = 0x0;
352 	iocp->io_class = __constant_cpu_to_be16(SRP_REV16A_IB_IO_CLASS);
353 	iocp->io_subclass = __constant_cpu_to_be16(SRP_IO_SUBCLASS);
354 	iocp->protocol = __constant_cpu_to_be16(SRP_PROTOCOL);
355 	iocp->protocol_version = __constant_cpu_to_be16(SRP_PROTOCOL_VERSION);
356 	iocp->send_queue_depth = cpu_to_be16(sdev->srq_size);
357 	iocp->rdma_read_depth = 4;
358 	iocp->send_size = cpu_to_be32(srp_max_req_size);
359 	iocp->rdma_size = cpu_to_be32(min(sport->port_attrib.srp_max_rdma_size,
360 					  1U << 24));
361 	iocp->num_svc_entries = 1;
362 	iocp->op_cap_mask = SRP_SEND_TO_IOC | SRP_SEND_FROM_IOC |
363 		SRP_RDMA_READ_FROM_IOC | SRP_RDMA_WRITE_FROM_IOC;
364 
365 	mad->mad_hdr.status = 0;
366 }
367 
368 /**
369  * srpt_get_svc_entries() - Write ServiceEntries to a management datagram.
370  *
371  * See also section 16.3.3.5 ServiceEntries in the InfiniBand Architecture
372  * Specification. See also section B.7, table B.8 in the SRP r16a document.
373  */
374 static void srpt_get_svc_entries(u64 ioc_guid,
375 				 u16 slot, u8 hi, u8 lo, struct ib_dm_mad *mad)
376 {
377 	struct ib_dm_svc_entries *svc_entries;
378 
379 	WARN_ON(!ioc_guid);
380 
381 	if (!slot || slot > 16) {
382 		mad->mad_hdr.status
383 			= __constant_cpu_to_be16(DM_MAD_STATUS_INVALID_FIELD);
384 		return;
385 	}
386 
387 	if (slot > 2 || lo > hi || hi > 1) {
388 		mad->mad_hdr.status
389 			= __constant_cpu_to_be16(DM_MAD_STATUS_NO_IOC);
390 		return;
391 	}
392 
393 	svc_entries = (struct ib_dm_svc_entries *)mad->data;
394 	memset(svc_entries, 0, sizeof *svc_entries);
395 	svc_entries->service_entries[0].id = cpu_to_be64(ioc_guid);
396 	snprintf(svc_entries->service_entries[0].name,
397 		 sizeof(svc_entries->service_entries[0].name),
398 		 "%s%016llx",
399 		 SRP_SERVICE_NAME_PREFIX,
400 		 ioc_guid);
401 
402 	mad->mad_hdr.status = 0;
403 }
404 
405 /**
406  * srpt_mgmt_method_get() - Process a received management datagram.
407  * @sp:      source port through which the MAD has been received.
408  * @rq_mad:  received MAD.
409  * @rsp_mad: response MAD.
410  */
411 static void srpt_mgmt_method_get(struct srpt_port *sp, struct ib_mad *rq_mad,
412 				 struct ib_dm_mad *rsp_mad)
413 {
414 	u16 attr_id;
415 	u32 slot;
416 	u8 hi, lo;
417 
418 	attr_id = be16_to_cpu(rq_mad->mad_hdr.attr_id);
419 	switch (attr_id) {
420 	case DM_ATTR_CLASS_PORT_INFO:
421 		srpt_get_class_port_info(rsp_mad);
422 		break;
423 	case DM_ATTR_IOU_INFO:
424 		srpt_get_iou(rsp_mad);
425 		break;
426 	case DM_ATTR_IOC_PROFILE:
427 		slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
428 		srpt_get_ioc(sp, slot, rsp_mad);
429 		break;
430 	case DM_ATTR_SVC_ENTRIES:
431 		slot = be32_to_cpu(rq_mad->mad_hdr.attr_mod);
432 		hi = (u8) ((slot >> 8) & 0xff);
433 		lo = (u8) (slot & 0xff);
434 		slot = (u16) ((slot >> 16) & 0xffff);
435 		srpt_get_svc_entries(srpt_service_guid,
436 				     slot, hi, lo, rsp_mad);
437 		break;
438 	default:
439 		rsp_mad->mad_hdr.status =
440 		    __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
441 		break;
442 	}
443 }
444 
445 /**
446  * srpt_mad_send_handler() - Post MAD-send callback function.
447  */
448 static void srpt_mad_send_handler(struct ib_mad_agent *mad_agent,
449 				  struct ib_mad_send_wc *mad_wc)
450 {
451 	ib_destroy_ah(mad_wc->send_buf->ah);
452 	ib_free_send_mad(mad_wc->send_buf);
453 }
454 
455 /**
456  * srpt_mad_recv_handler() - MAD reception callback function.
457  */
458 static void srpt_mad_recv_handler(struct ib_mad_agent *mad_agent,
459 				  struct ib_mad_recv_wc *mad_wc)
460 {
461 	struct srpt_port *sport = (struct srpt_port *)mad_agent->context;
462 	struct ib_ah *ah;
463 	struct ib_mad_send_buf *rsp;
464 	struct ib_dm_mad *dm_mad;
465 
466 	if (!mad_wc || !mad_wc->recv_buf.mad)
467 		return;
468 
469 	ah = ib_create_ah_from_wc(mad_agent->qp->pd, mad_wc->wc,
470 				  mad_wc->recv_buf.grh, mad_agent->port_num);
471 	if (IS_ERR(ah))
472 		goto err;
473 
474 	BUILD_BUG_ON(offsetof(struct ib_dm_mad, data) != IB_MGMT_DEVICE_HDR);
475 
476 	rsp = ib_create_send_mad(mad_agent, mad_wc->wc->src_qp,
477 				 mad_wc->wc->pkey_index, 0,
478 				 IB_MGMT_DEVICE_HDR, IB_MGMT_DEVICE_DATA,
479 				 GFP_KERNEL);
480 	if (IS_ERR(rsp))
481 		goto err_rsp;
482 
483 	rsp->ah = ah;
484 
485 	dm_mad = rsp->mad;
486 	memcpy(dm_mad, mad_wc->recv_buf.mad, sizeof *dm_mad);
487 	dm_mad->mad_hdr.method = IB_MGMT_METHOD_GET_RESP;
488 	dm_mad->mad_hdr.status = 0;
489 
490 	switch (mad_wc->recv_buf.mad->mad_hdr.method) {
491 	case IB_MGMT_METHOD_GET:
492 		srpt_mgmt_method_get(sport, mad_wc->recv_buf.mad, dm_mad);
493 		break;
494 	case IB_MGMT_METHOD_SET:
495 		dm_mad->mad_hdr.status =
496 		    __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD_ATTR);
497 		break;
498 	default:
499 		dm_mad->mad_hdr.status =
500 		    __constant_cpu_to_be16(DM_MAD_STATUS_UNSUP_METHOD);
501 		break;
502 	}
503 
504 	if (!ib_post_send_mad(rsp, NULL)) {
505 		ib_free_recv_mad(mad_wc);
506 		/* will destroy_ah & free_send_mad in send completion */
507 		return;
508 	}
509 
510 	ib_free_send_mad(rsp);
511 
512 err_rsp:
513 	ib_destroy_ah(ah);
514 err:
515 	ib_free_recv_mad(mad_wc);
516 }
517 
518 /**
519  * srpt_refresh_port() - Configure a HCA port.
520  *
521  * Enable InfiniBand management datagram processing, update the cached sm_lid,
522  * lid and gid values, and register a callback function for processing MADs
523  * on the specified port.
524  *
525  * Note: It is safe to call this function more than once for the same port.
526  */
527 static int srpt_refresh_port(struct srpt_port *sport)
528 {
529 	struct ib_mad_reg_req reg_req;
530 	struct ib_port_modify port_modify;
531 	struct ib_port_attr port_attr;
532 	int ret;
533 
534 	memset(&port_modify, 0, sizeof port_modify);
535 	port_modify.set_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
536 	port_modify.clr_port_cap_mask = 0;
537 
538 	ret = ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
539 	if (ret)
540 		goto err_mod_port;
541 
542 	ret = ib_query_port(sport->sdev->device, sport->port, &port_attr);
543 	if (ret)
544 		goto err_query_port;
545 
546 	sport->sm_lid = port_attr.sm_lid;
547 	sport->lid = port_attr.lid;
548 
549 	ret = ib_query_gid(sport->sdev->device, sport->port, 0, &sport->gid);
550 	if (ret)
551 		goto err_query_port;
552 
553 	if (!sport->mad_agent) {
554 		memset(&reg_req, 0, sizeof reg_req);
555 		reg_req.mgmt_class = IB_MGMT_CLASS_DEVICE_MGMT;
556 		reg_req.mgmt_class_version = IB_MGMT_BASE_VERSION;
557 		set_bit(IB_MGMT_METHOD_GET, reg_req.method_mask);
558 		set_bit(IB_MGMT_METHOD_SET, reg_req.method_mask);
559 
560 		sport->mad_agent = ib_register_mad_agent(sport->sdev->device,
561 							 sport->port,
562 							 IB_QPT_GSI,
563 							 &reg_req, 0,
564 							 srpt_mad_send_handler,
565 							 srpt_mad_recv_handler,
566 							 sport);
567 		if (IS_ERR(sport->mad_agent)) {
568 			ret = PTR_ERR(sport->mad_agent);
569 			sport->mad_agent = NULL;
570 			goto err_query_port;
571 		}
572 	}
573 
574 	return 0;
575 
576 err_query_port:
577 
578 	port_modify.set_port_cap_mask = 0;
579 	port_modify.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP;
580 	ib_modify_port(sport->sdev->device, sport->port, 0, &port_modify);
581 
582 err_mod_port:
583 
584 	return ret;
585 }
586 
587 /**
588  * srpt_unregister_mad_agent() - Unregister MAD callback functions.
589  *
590  * Note: It is safe to call this function more than once for the same device.
591  */
592 static void srpt_unregister_mad_agent(struct srpt_device *sdev)
593 {
594 	struct ib_port_modify port_modify = {
595 		.clr_port_cap_mask = IB_PORT_DEVICE_MGMT_SUP,
596 	};
597 	struct srpt_port *sport;
598 	int i;
599 
600 	for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
601 		sport = &sdev->port[i - 1];
602 		WARN_ON(sport->port != i);
603 		if (ib_modify_port(sdev->device, i, 0, &port_modify) < 0)
604 			printk(KERN_ERR "disabling MAD processing failed.\n");
605 		if (sport->mad_agent) {
606 			ib_unregister_mad_agent(sport->mad_agent);
607 			sport->mad_agent = NULL;
608 		}
609 	}
610 }
611 
612 /**
613  * srpt_alloc_ioctx() - Allocate an SRPT I/O context structure.
614  */
615 static struct srpt_ioctx *srpt_alloc_ioctx(struct srpt_device *sdev,
616 					   int ioctx_size, int dma_size,
617 					   enum dma_data_direction dir)
618 {
619 	struct srpt_ioctx *ioctx;
620 
621 	ioctx = kmalloc(ioctx_size, GFP_KERNEL);
622 	if (!ioctx)
623 		goto err;
624 
625 	ioctx->buf = kmalloc(dma_size, GFP_KERNEL);
626 	if (!ioctx->buf)
627 		goto err_free_ioctx;
628 
629 	ioctx->dma = ib_dma_map_single(sdev->device, ioctx->buf, dma_size, dir);
630 	if (ib_dma_mapping_error(sdev->device, ioctx->dma))
631 		goto err_free_buf;
632 
633 	return ioctx;
634 
635 err_free_buf:
636 	kfree(ioctx->buf);
637 err_free_ioctx:
638 	kfree(ioctx);
639 err:
640 	return NULL;
641 }
642 
643 /**
644  * srpt_free_ioctx() - Free an SRPT I/O context structure.
645  */
646 static void srpt_free_ioctx(struct srpt_device *sdev, struct srpt_ioctx *ioctx,
647 			    int dma_size, enum dma_data_direction dir)
648 {
649 	if (!ioctx)
650 		return;
651 
652 	ib_dma_unmap_single(sdev->device, ioctx->dma, dma_size, dir);
653 	kfree(ioctx->buf);
654 	kfree(ioctx);
655 }
656 
657 /**
658  * srpt_alloc_ioctx_ring() - Allocate a ring of SRPT I/O context structures.
659  * @sdev:       Device to allocate the I/O context ring for.
660  * @ring_size:  Number of elements in the I/O context ring.
661  * @ioctx_size: I/O context size.
662  * @dma_size:   DMA buffer size.
663  * @dir:        DMA data direction.
664  */
665 static struct srpt_ioctx **srpt_alloc_ioctx_ring(struct srpt_device *sdev,
666 				int ring_size, int ioctx_size,
667 				int dma_size, enum dma_data_direction dir)
668 {
669 	struct srpt_ioctx **ring;
670 	int i;
671 
672 	WARN_ON(ioctx_size != sizeof(struct srpt_recv_ioctx)
673 		&& ioctx_size != sizeof(struct srpt_send_ioctx));
674 
675 	ring = kmalloc(ring_size * sizeof(ring[0]), GFP_KERNEL);
676 	if (!ring)
677 		goto out;
678 	for (i = 0; i < ring_size; ++i) {
679 		ring[i] = srpt_alloc_ioctx(sdev, ioctx_size, dma_size, dir);
680 		if (!ring[i])
681 			goto err;
682 		ring[i]->index = i;
683 	}
684 	goto out;
685 
686 err:
687 	while (--i >= 0)
688 		srpt_free_ioctx(sdev, ring[i], dma_size, dir);
689 	kfree(ring);
690 	ring = NULL;
691 out:
692 	return ring;
693 }
694 
695 /**
696  * srpt_free_ioctx_ring() - Free the ring of SRPT I/O context structures.
697  */
698 static void srpt_free_ioctx_ring(struct srpt_ioctx **ioctx_ring,
699 				 struct srpt_device *sdev, int ring_size,
700 				 int dma_size, enum dma_data_direction dir)
701 {
702 	int i;
703 
704 	for (i = 0; i < ring_size; ++i)
705 		srpt_free_ioctx(sdev, ioctx_ring[i], dma_size, dir);
706 	kfree(ioctx_ring);
707 }
708 
709 /**
710  * srpt_get_cmd_state() - Get the state of a SCSI command.
711  */
712 static enum srpt_command_state srpt_get_cmd_state(struct srpt_send_ioctx *ioctx)
713 {
714 	enum srpt_command_state state;
715 	unsigned long flags;
716 
717 	BUG_ON(!ioctx);
718 
719 	spin_lock_irqsave(&ioctx->spinlock, flags);
720 	state = ioctx->state;
721 	spin_unlock_irqrestore(&ioctx->spinlock, flags);
722 	return state;
723 }
724 
725 /**
726  * srpt_set_cmd_state() - Set the state of a SCSI command.
727  *
728  * Does not modify the state of aborted commands. Returns the previous command
729  * state.
730  */
731 static enum srpt_command_state srpt_set_cmd_state(struct srpt_send_ioctx *ioctx,
732 						  enum srpt_command_state new)
733 {
734 	enum srpt_command_state previous;
735 	unsigned long flags;
736 
737 	BUG_ON(!ioctx);
738 
739 	spin_lock_irqsave(&ioctx->spinlock, flags);
740 	previous = ioctx->state;
741 	if (previous != SRPT_STATE_DONE)
742 		ioctx->state = new;
743 	spin_unlock_irqrestore(&ioctx->spinlock, flags);
744 
745 	return previous;
746 }
747 
748 /**
749  * srpt_test_and_set_cmd_state() - Test and set the state of a command.
750  *
751  * Returns true if and only if the previous command state was equal to 'old'.
752  */
753 static bool srpt_test_and_set_cmd_state(struct srpt_send_ioctx *ioctx,
754 					enum srpt_command_state old,
755 					enum srpt_command_state new)
756 {
757 	enum srpt_command_state previous;
758 	unsigned long flags;
759 
760 	WARN_ON(!ioctx);
761 	WARN_ON(old == SRPT_STATE_DONE);
762 	WARN_ON(new == SRPT_STATE_NEW);
763 
764 	spin_lock_irqsave(&ioctx->spinlock, flags);
765 	previous = ioctx->state;
766 	if (previous == old)
767 		ioctx->state = new;
768 	spin_unlock_irqrestore(&ioctx->spinlock, flags);
769 	return previous == old;
770 }
771 
772 /**
773  * srpt_post_recv() - Post an IB receive request.
774  */
775 static int srpt_post_recv(struct srpt_device *sdev,
776 			  struct srpt_recv_ioctx *ioctx)
777 {
778 	struct ib_sge list;
779 	struct ib_recv_wr wr, *bad_wr;
780 
781 	BUG_ON(!sdev);
782 	wr.wr_id = encode_wr_id(SRPT_RECV, ioctx->ioctx.index);
783 
784 	list.addr = ioctx->ioctx.dma;
785 	list.length = srp_max_req_size;
786 	list.lkey = sdev->mr->lkey;
787 
788 	wr.next = NULL;
789 	wr.sg_list = &list;
790 	wr.num_sge = 1;
791 
792 	return ib_post_srq_recv(sdev->srq, &wr, &bad_wr);
793 }
794 
795 /**
796  * srpt_post_send() - Post an IB send request.
797  *
798  * Returns zero upon success and a non-zero value upon failure.
799  */
800 static int srpt_post_send(struct srpt_rdma_ch *ch,
801 			  struct srpt_send_ioctx *ioctx, int len)
802 {
803 	struct ib_sge list;
804 	struct ib_send_wr wr, *bad_wr;
805 	struct srpt_device *sdev = ch->sport->sdev;
806 	int ret;
807 
808 	atomic_inc(&ch->req_lim);
809 
810 	ret = -ENOMEM;
811 	if (unlikely(atomic_dec_return(&ch->sq_wr_avail) < 0)) {
812 		printk(KERN_WARNING "IB send queue full (needed 1)\n");
813 		goto out;
814 	}
815 
816 	ib_dma_sync_single_for_device(sdev->device, ioctx->ioctx.dma, len,
817 				      DMA_TO_DEVICE);
818 
819 	list.addr = ioctx->ioctx.dma;
820 	list.length = len;
821 	list.lkey = sdev->mr->lkey;
822 
823 	wr.next = NULL;
824 	wr.wr_id = encode_wr_id(SRPT_SEND, ioctx->ioctx.index);
825 	wr.sg_list = &list;
826 	wr.num_sge = 1;
827 	wr.opcode = IB_WR_SEND;
828 	wr.send_flags = IB_SEND_SIGNALED;
829 
830 	ret = ib_post_send(ch->qp, &wr, &bad_wr);
831 
832 out:
833 	if (ret < 0) {
834 		atomic_inc(&ch->sq_wr_avail);
835 		atomic_dec(&ch->req_lim);
836 	}
837 	return ret;
838 }
839 
840 /**
841  * srpt_get_desc_tbl() - Parse the data descriptors of an SRP_CMD request.
842  * @ioctx: Pointer to the I/O context associated with the request.
843  * @srp_cmd: Pointer to the SRP_CMD request data.
844  * @dir: Pointer to the variable to which the transfer direction will be
845  *   written.
846  * @data_len: Pointer to the variable to which the total data length of all
847  *   descriptors in the SRP_CMD request will be written.
848  *
849  * This function initializes ioctx->nrbuf and ioctx->r_bufs.
850  *
851  * Returns -EINVAL when the SRP_CMD request contains inconsistent descriptors;
852  * -ENOMEM when memory allocation fails and zero upon success.
853  */
854 static int srpt_get_desc_tbl(struct srpt_send_ioctx *ioctx,
855 			     struct srp_cmd *srp_cmd,
856 			     enum dma_data_direction *dir, u64 *data_len)
857 {
858 	struct srp_indirect_buf *idb;
859 	struct srp_direct_buf *db;
860 	unsigned add_cdb_offset;
861 	int ret;
862 
863 	/*
864 	 * The pointer computations below will only be compiled correctly
865 	 * if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
866 	 * whether srp_cmd::add_data has been declared as a byte pointer.
867 	 */
868 	BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0)
869 		     && !__same_type(srp_cmd->add_data[0], (u8)0));
870 
871 	BUG_ON(!dir);
872 	BUG_ON(!data_len);
873 
874 	ret = 0;
875 	*data_len = 0;
876 
877 	/*
878 	 * The lower four bits of the buffer format field contain the DATA-IN
879 	 * buffer descriptor format, and the highest four bits contain the
880 	 * DATA-OUT buffer descriptor format.
881 	 */
882 	*dir = DMA_NONE;
883 	if (srp_cmd->buf_fmt & 0xf)
884 		/* DATA-IN: transfer data from target to initiator (read). */
885 		*dir = DMA_FROM_DEVICE;
886 	else if (srp_cmd->buf_fmt >> 4)
887 		/* DATA-OUT: transfer data from initiator to target (write). */
888 		*dir = DMA_TO_DEVICE;
889 
890 	/*
891 	 * According to the SRP spec, the lower two bits of the 'ADDITIONAL
892 	 * CDB LENGTH' field are reserved and the size in bytes of this field
893 	 * is four times the value specified in bits 3..7. Hence the "& ~3".
894 	 */
895 	add_cdb_offset = srp_cmd->add_cdb_len & ~3;
896 	if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
897 	    ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
898 		ioctx->n_rbuf = 1;
899 		ioctx->rbufs = &ioctx->single_rbuf;
900 
901 		db = (struct srp_direct_buf *)(srp_cmd->add_data
902 					       + add_cdb_offset);
903 		memcpy(ioctx->rbufs, db, sizeof *db);
904 		*data_len = be32_to_cpu(db->len);
905 	} else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
906 		   ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
907 		idb = (struct srp_indirect_buf *)(srp_cmd->add_data
908 						  + add_cdb_offset);
909 
910 		ioctx->n_rbuf = be32_to_cpu(idb->table_desc.len) / sizeof *db;
911 
912 		if (ioctx->n_rbuf >
913 		    (srp_cmd->data_out_desc_cnt + srp_cmd->data_in_desc_cnt)) {
914 			printk(KERN_ERR "received unsupported SRP_CMD request"
915 			       " type (%u out + %u in != %u / %zu)\n",
916 			       srp_cmd->data_out_desc_cnt,
917 			       srp_cmd->data_in_desc_cnt,
918 			       be32_to_cpu(idb->table_desc.len),
919 			       sizeof(*db));
920 			ioctx->n_rbuf = 0;
921 			ret = -EINVAL;
922 			goto out;
923 		}
924 
925 		if (ioctx->n_rbuf == 1)
926 			ioctx->rbufs = &ioctx->single_rbuf;
927 		else {
928 			ioctx->rbufs =
929 				kmalloc(ioctx->n_rbuf * sizeof *db, GFP_ATOMIC);
930 			if (!ioctx->rbufs) {
931 				ioctx->n_rbuf = 0;
932 				ret = -ENOMEM;
933 				goto out;
934 			}
935 		}
936 
937 		db = idb->desc_list;
938 		memcpy(ioctx->rbufs, db, ioctx->n_rbuf * sizeof *db);
939 		*data_len = be32_to_cpu(idb->len);
940 	}
941 out:
942 	return ret;
943 }
944 
945 /**
946  * srpt_init_ch_qp() - Initialize queue pair attributes.
947  *
948  * Initialized the attributes of queue pair 'qp' by allowing local write,
949  * remote read and remote write. Also transitions 'qp' to state IB_QPS_INIT.
950  */
951 static int srpt_init_ch_qp(struct srpt_rdma_ch *ch, struct ib_qp *qp)
952 {
953 	struct ib_qp_attr *attr;
954 	int ret;
955 
956 	attr = kzalloc(sizeof *attr, GFP_KERNEL);
957 	if (!attr)
958 		return -ENOMEM;
959 
960 	attr->qp_state = IB_QPS_INIT;
961 	attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ |
962 	    IB_ACCESS_REMOTE_WRITE;
963 	attr->port_num = ch->sport->port;
964 	attr->pkey_index = 0;
965 
966 	ret = ib_modify_qp(qp, attr,
967 			   IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PORT |
968 			   IB_QP_PKEY_INDEX);
969 
970 	kfree(attr);
971 	return ret;
972 }
973 
974 /**
975  * srpt_ch_qp_rtr() - Change the state of a channel to 'ready to receive' (RTR).
976  * @ch: channel of the queue pair.
977  * @qp: queue pair to change the state of.
978  *
979  * Returns zero upon success and a negative value upon failure.
980  *
981  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
982  * If this structure ever becomes larger, it might be necessary to allocate
983  * it dynamically instead of on the stack.
984  */
985 static int srpt_ch_qp_rtr(struct srpt_rdma_ch *ch, struct ib_qp *qp)
986 {
987 	struct ib_qp_attr qp_attr;
988 	int attr_mask;
989 	int ret;
990 
991 	qp_attr.qp_state = IB_QPS_RTR;
992 	ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
993 	if (ret)
994 		goto out;
995 
996 	qp_attr.max_dest_rd_atomic = 4;
997 
998 	ret = ib_modify_qp(qp, &qp_attr, attr_mask);
999 
1000 out:
1001 	return ret;
1002 }
1003 
1004 /**
1005  * srpt_ch_qp_rts() - Change the state of a channel to 'ready to send' (RTS).
1006  * @ch: channel of the queue pair.
1007  * @qp: queue pair to change the state of.
1008  *
1009  * Returns zero upon success and a negative value upon failure.
1010  *
1011  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
1012  * If this structure ever becomes larger, it might be necessary to allocate
1013  * it dynamically instead of on the stack.
1014  */
1015 static int srpt_ch_qp_rts(struct srpt_rdma_ch *ch, struct ib_qp *qp)
1016 {
1017 	struct ib_qp_attr qp_attr;
1018 	int attr_mask;
1019 	int ret;
1020 
1021 	qp_attr.qp_state = IB_QPS_RTS;
1022 	ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
1023 	if (ret)
1024 		goto out;
1025 
1026 	qp_attr.max_rd_atomic = 4;
1027 
1028 	ret = ib_modify_qp(qp, &qp_attr, attr_mask);
1029 
1030 out:
1031 	return ret;
1032 }
1033 
1034 /**
1035  * srpt_ch_qp_err() - Set the channel queue pair state to 'error'.
1036  */
1037 static int srpt_ch_qp_err(struct srpt_rdma_ch *ch)
1038 {
1039 	struct ib_qp_attr qp_attr;
1040 
1041 	qp_attr.qp_state = IB_QPS_ERR;
1042 	return ib_modify_qp(ch->qp, &qp_attr, IB_QP_STATE);
1043 }
1044 
1045 /**
1046  * srpt_unmap_sg_to_ib_sge() - Unmap an IB SGE list.
1047  */
1048 static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1049 				    struct srpt_send_ioctx *ioctx)
1050 {
1051 	struct scatterlist *sg;
1052 	enum dma_data_direction dir;
1053 
1054 	BUG_ON(!ch);
1055 	BUG_ON(!ioctx);
1056 	BUG_ON(ioctx->n_rdma && !ioctx->rdma_ius);
1057 
1058 	while (ioctx->n_rdma)
1059 		kfree(ioctx->rdma_ius[--ioctx->n_rdma].sge);
1060 
1061 	kfree(ioctx->rdma_ius);
1062 	ioctx->rdma_ius = NULL;
1063 
1064 	if (ioctx->mapped_sg_count) {
1065 		sg = ioctx->sg;
1066 		WARN_ON(!sg);
1067 		dir = ioctx->cmd.data_direction;
1068 		BUG_ON(dir == DMA_NONE);
1069 		ib_dma_unmap_sg(ch->sport->sdev->device, sg, ioctx->sg_cnt,
1070 				opposite_dma_dir(dir));
1071 		ioctx->mapped_sg_count = 0;
1072 	}
1073 }
1074 
1075 /**
1076  * srpt_map_sg_to_ib_sge() - Map an SG list to an IB SGE list.
1077  */
1078 static int srpt_map_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1079 				 struct srpt_send_ioctx *ioctx)
1080 {
1081 	struct se_cmd *cmd;
1082 	struct scatterlist *sg, *sg_orig;
1083 	int sg_cnt;
1084 	enum dma_data_direction dir;
1085 	struct rdma_iu *riu;
1086 	struct srp_direct_buf *db;
1087 	dma_addr_t dma_addr;
1088 	struct ib_sge *sge;
1089 	u64 raddr;
1090 	u32 rsize;
1091 	u32 tsize;
1092 	u32 dma_len;
1093 	int count, nrdma;
1094 	int i, j, k;
1095 
1096 	BUG_ON(!ch);
1097 	BUG_ON(!ioctx);
1098 	cmd = &ioctx->cmd;
1099 	dir = cmd->data_direction;
1100 	BUG_ON(dir == DMA_NONE);
1101 
1102 	ioctx->sg = sg = sg_orig = cmd->t_data_sg;
1103 	ioctx->sg_cnt = sg_cnt = cmd->t_data_nents;
1104 
1105 	count = ib_dma_map_sg(ch->sport->sdev->device, sg, sg_cnt,
1106 			      opposite_dma_dir(dir));
1107 	if (unlikely(!count))
1108 		return -EAGAIN;
1109 
1110 	ioctx->mapped_sg_count = count;
1111 
1112 	if (ioctx->rdma_ius && ioctx->n_rdma_ius)
1113 		nrdma = ioctx->n_rdma_ius;
1114 	else {
1115 		nrdma = (count + SRPT_DEF_SG_PER_WQE - 1) / SRPT_DEF_SG_PER_WQE
1116 			+ ioctx->n_rbuf;
1117 
1118 		ioctx->rdma_ius = kzalloc(nrdma * sizeof *riu, GFP_KERNEL);
1119 		if (!ioctx->rdma_ius)
1120 			goto free_mem;
1121 
1122 		ioctx->n_rdma_ius = nrdma;
1123 	}
1124 
1125 	db = ioctx->rbufs;
1126 	tsize = cmd->data_length;
1127 	dma_len = sg_dma_len(&sg[0]);
1128 	riu = ioctx->rdma_ius;
1129 
1130 	/*
1131 	 * For each remote desc - calculate the #ib_sge.
1132 	 * If #ib_sge < SRPT_DEF_SG_PER_WQE per rdma operation then
1133 	 *      each remote desc rdma_iu is required a rdma wr;
1134 	 * else
1135 	 *      we need to allocate extra rdma_iu to carry extra #ib_sge in
1136 	 *      another rdma wr
1137 	 */
1138 	for (i = 0, j = 0;
1139 	     j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
1140 		rsize = be32_to_cpu(db->len);
1141 		raddr = be64_to_cpu(db->va);
1142 		riu->raddr = raddr;
1143 		riu->rkey = be32_to_cpu(db->key);
1144 		riu->sge_cnt = 0;
1145 
1146 		/* calculate how many sge required for this remote_buf */
1147 		while (rsize > 0 && tsize > 0) {
1148 
1149 			if (rsize >= dma_len) {
1150 				tsize -= dma_len;
1151 				rsize -= dma_len;
1152 				raddr += dma_len;
1153 
1154 				if (tsize > 0) {
1155 					++j;
1156 					if (j < count) {
1157 						sg = sg_next(sg);
1158 						dma_len = sg_dma_len(sg);
1159 					}
1160 				}
1161 			} else {
1162 				tsize -= rsize;
1163 				dma_len -= rsize;
1164 				rsize = 0;
1165 			}
1166 
1167 			++riu->sge_cnt;
1168 
1169 			if (rsize > 0 && riu->sge_cnt == SRPT_DEF_SG_PER_WQE) {
1170 				++ioctx->n_rdma;
1171 				riu->sge =
1172 				    kmalloc(riu->sge_cnt * sizeof *riu->sge,
1173 					    GFP_KERNEL);
1174 				if (!riu->sge)
1175 					goto free_mem;
1176 
1177 				++riu;
1178 				riu->sge_cnt = 0;
1179 				riu->raddr = raddr;
1180 				riu->rkey = be32_to_cpu(db->key);
1181 			}
1182 		}
1183 
1184 		++ioctx->n_rdma;
1185 		riu->sge = kmalloc(riu->sge_cnt * sizeof *riu->sge,
1186 				   GFP_KERNEL);
1187 		if (!riu->sge)
1188 			goto free_mem;
1189 	}
1190 
1191 	db = ioctx->rbufs;
1192 	tsize = cmd->data_length;
1193 	riu = ioctx->rdma_ius;
1194 	sg = sg_orig;
1195 	dma_len = sg_dma_len(&sg[0]);
1196 	dma_addr = sg_dma_address(&sg[0]);
1197 
1198 	/* this second loop is really mapped sg_addres to rdma_iu->ib_sge */
1199 	for (i = 0, j = 0;
1200 	     j < count && i < ioctx->n_rbuf && tsize > 0; ++i, ++riu, ++db) {
1201 		rsize = be32_to_cpu(db->len);
1202 		sge = riu->sge;
1203 		k = 0;
1204 
1205 		while (rsize > 0 && tsize > 0) {
1206 			sge->addr = dma_addr;
1207 			sge->lkey = ch->sport->sdev->mr->lkey;
1208 
1209 			if (rsize >= dma_len) {
1210 				sge->length =
1211 					(tsize < dma_len) ? tsize : dma_len;
1212 				tsize -= dma_len;
1213 				rsize -= dma_len;
1214 
1215 				if (tsize > 0) {
1216 					++j;
1217 					if (j < count) {
1218 						sg = sg_next(sg);
1219 						dma_len = sg_dma_len(sg);
1220 						dma_addr = sg_dma_address(sg);
1221 					}
1222 				}
1223 			} else {
1224 				sge->length = (tsize < rsize) ? tsize : rsize;
1225 				tsize -= rsize;
1226 				dma_len -= rsize;
1227 				dma_addr += rsize;
1228 				rsize = 0;
1229 			}
1230 
1231 			++k;
1232 			if (k == riu->sge_cnt && rsize > 0 && tsize > 0) {
1233 				++riu;
1234 				sge = riu->sge;
1235 				k = 0;
1236 			} else if (rsize > 0 && tsize > 0)
1237 				++sge;
1238 		}
1239 	}
1240 
1241 	return 0;
1242 
1243 free_mem:
1244 	srpt_unmap_sg_to_ib_sge(ch, ioctx);
1245 
1246 	return -ENOMEM;
1247 }
1248 
1249 /**
1250  * srpt_get_send_ioctx() - Obtain an I/O context for sending to the initiator.
1251  */
1252 static struct srpt_send_ioctx *srpt_get_send_ioctx(struct srpt_rdma_ch *ch)
1253 {
1254 	struct srpt_send_ioctx *ioctx;
1255 	unsigned long flags;
1256 
1257 	BUG_ON(!ch);
1258 
1259 	ioctx = NULL;
1260 	spin_lock_irqsave(&ch->spinlock, flags);
1261 	if (!list_empty(&ch->free_list)) {
1262 		ioctx = list_first_entry(&ch->free_list,
1263 					 struct srpt_send_ioctx, free_list);
1264 		list_del(&ioctx->free_list);
1265 	}
1266 	spin_unlock_irqrestore(&ch->spinlock, flags);
1267 
1268 	if (!ioctx)
1269 		return ioctx;
1270 
1271 	BUG_ON(ioctx->ch != ch);
1272 	kref_init(&ioctx->kref);
1273 	spin_lock_init(&ioctx->spinlock);
1274 	ioctx->state = SRPT_STATE_NEW;
1275 	ioctx->n_rbuf = 0;
1276 	ioctx->rbufs = NULL;
1277 	ioctx->n_rdma = 0;
1278 	ioctx->n_rdma_ius = 0;
1279 	ioctx->rdma_ius = NULL;
1280 	ioctx->mapped_sg_count = 0;
1281 	init_completion(&ioctx->tx_done);
1282 	ioctx->queue_status_only = false;
1283 	/*
1284 	 * transport_init_se_cmd() does not initialize all fields, so do it
1285 	 * here.
1286 	 */
1287 	memset(&ioctx->cmd, 0, sizeof(ioctx->cmd));
1288 	memset(&ioctx->sense_data, 0, sizeof(ioctx->sense_data));
1289 
1290 	return ioctx;
1291 }
1292 
1293 /**
1294  * srpt_put_send_ioctx() - Free up resources.
1295  */
1296 static void srpt_put_send_ioctx(struct srpt_send_ioctx *ioctx)
1297 {
1298 	struct srpt_rdma_ch *ch;
1299 	unsigned long flags;
1300 
1301 	BUG_ON(!ioctx);
1302 	ch = ioctx->ch;
1303 	BUG_ON(!ch);
1304 
1305 	WARN_ON(srpt_get_cmd_state(ioctx) != SRPT_STATE_DONE);
1306 
1307 	srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
1308 	transport_generic_free_cmd(&ioctx->cmd, 0);
1309 
1310 	if (ioctx->n_rbuf > 1) {
1311 		kfree(ioctx->rbufs);
1312 		ioctx->rbufs = NULL;
1313 		ioctx->n_rbuf = 0;
1314 	}
1315 
1316 	spin_lock_irqsave(&ch->spinlock, flags);
1317 	list_add(&ioctx->free_list, &ch->free_list);
1318 	spin_unlock_irqrestore(&ch->spinlock, flags);
1319 }
1320 
1321 static void srpt_put_send_ioctx_kref(struct kref *kref)
1322 {
1323 	srpt_put_send_ioctx(container_of(kref, struct srpt_send_ioctx, kref));
1324 }
1325 
1326 /**
1327  * srpt_abort_cmd() - Abort a SCSI command.
1328  * @ioctx:   I/O context associated with the SCSI command.
1329  * @context: Preferred execution context.
1330  */
1331 static int srpt_abort_cmd(struct srpt_send_ioctx *ioctx)
1332 {
1333 	enum srpt_command_state state;
1334 	unsigned long flags;
1335 
1336 	BUG_ON(!ioctx);
1337 
1338 	/*
1339 	 * If the command is in a state where the target core is waiting for
1340 	 * the ib_srpt driver, change the state to the next state. Changing
1341 	 * the state of the command from SRPT_STATE_NEED_DATA to
1342 	 * SRPT_STATE_DATA_IN ensures that srpt_xmit_response() will call this
1343 	 * function a second time.
1344 	 */
1345 
1346 	spin_lock_irqsave(&ioctx->spinlock, flags);
1347 	state = ioctx->state;
1348 	switch (state) {
1349 	case SRPT_STATE_NEED_DATA:
1350 		ioctx->state = SRPT_STATE_DATA_IN;
1351 		break;
1352 	case SRPT_STATE_DATA_IN:
1353 	case SRPT_STATE_CMD_RSP_SENT:
1354 	case SRPT_STATE_MGMT_RSP_SENT:
1355 		ioctx->state = SRPT_STATE_DONE;
1356 		break;
1357 	default:
1358 		break;
1359 	}
1360 	spin_unlock_irqrestore(&ioctx->spinlock, flags);
1361 
1362 	if (state == SRPT_STATE_DONE)
1363 		goto out;
1364 
1365 	pr_debug("Aborting cmd with state %d and tag %lld\n", state,
1366 		 ioctx->tag);
1367 
1368 	switch (state) {
1369 	case SRPT_STATE_NEW:
1370 	case SRPT_STATE_DATA_IN:
1371 	case SRPT_STATE_MGMT:
1372 		/*
1373 		 * Do nothing - defer abort processing until
1374 		 * srpt_queue_response() is invoked.
1375 		 */
1376 		WARN_ON(!transport_check_aborted_status(&ioctx->cmd, false));
1377 		break;
1378 	case SRPT_STATE_NEED_DATA:
1379 		/* DMA_TO_DEVICE (write) - RDMA read error. */
1380 
1381 		/* XXX(hch): this is a horrible layering violation.. */
1382 		spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1383 		ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1384 		ioctx->cmd.transport_state &= ~CMD_T_ACTIVE;
1385 		spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1386 
1387 		complete(&ioctx->cmd.transport_lun_stop_comp);
1388 		break;
1389 	case SRPT_STATE_CMD_RSP_SENT:
1390 		/*
1391 		 * SRP_RSP sending failed or the SRP_RSP send completion has
1392 		 * not been received in time.
1393 		 */
1394 		srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
1395 		spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1396 		ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1397 		spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1398 		kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1399 		break;
1400 	case SRPT_STATE_MGMT_RSP_SENT:
1401 		srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1402 		kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1403 		break;
1404 	default:
1405 		WARN_ON("ERROR: unexpected command state");
1406 		break;
1407 	}
1408 
1409 out:
1410 	return state;
1411 }
1412 
1413 /**
1414  * srpt_handle_send_err_comp() - Process an IB_WC_SEND error completion.
1415  */
1416 static void srpt_handle_send_err_comp(struct srpt_rdma_ch *ch, u64 wr_id)
1417 {
1418 	struct srpt_send_ioctx *ioctx;
1419 	enum srpt_command_state state;
1420 	struct se_cmd *cmd;
1421 	u32 index;
1422 
1423 	atomic_inc(&ch->sq_wr_avail);
1424 
1425 	index = idx_from_wr_id(wr_id);
1426 	ioctx = ch->ioctx_ring[index];
1427 	state = srpt_get_cmd_state(ioctx);
1428 	cmd = &ioctx->cmd;
1429 
1430 	WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1431 		&& state != SRPT_STATE_MGMT_RSP_SENT
1432 		&& state != SRPT_STATE_NEED_DATA
1433 		&& state != SRPT_STATE_DONE);
1434 
1435 	/* If SRP_RSP sending failed, undo the ch->req_lim change. */
1436 	if (state == SRPT_STATE_CMD_RSP_SENT
1437 	    || state == SRPT_STATE_MGMT_RSP_SENT)
1438 		atomic_dec(&ch->req_lim);
1439 
1440 	srpt_abort_cmd(ioctx);
1441 }
1442 
1443 /**
1444  * srpt_handle_send_comp() - Process an IB send completion notification.
1445  */
1446 static void srpt_handle_send_comp(struct srpt_rdma_ch *ch,
1447 				  struct srpt_send_ioctx *ioctx)
1448 {
1449 	enum srpt_command_state state;
1450 
1451 	atomic_inc(&ch->sq_wr_avail);
1452 
1453 	state = srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1454 
1455 	if (WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1456 		    && state != SRPT_STATE_MGMT_RSP_SENT
1457 		    && state != SRPT_STATE_DONE))
1458 		pr_debug("state = %d\n", state);
1459 
1460 	if (state != SRPT_STATE_DONE)
1461 		kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1462 	else
1463 		printk(KERN_ERR "IB completion has been received too late for"
1464 		       " wr_id = %u.\n", ioctx->ioctx.index);
1465 }
1466 
1467 /**
1468  * srpt_handle_rdma_comp() - Process an IB RDMA completion notification.
1469  *
1470  * XXX: what is now target_execute_cmd used to be asynchronous, and unmapping
1471  * the data that has been transferred via IB RDMA had to be postponed until the
1472  * check_stop_free() callback.  None of this is necessary anymore and needs to
1473  * be cleaned up.
1474  */
1475 static void srpt_handle_rdma_comp(struct srpt_rdma_ch *ch,
1476 				  struct srpt_send_ioctx *ioctx,
1477 				  enum srpt_opcode opcode)
1478 {
1479 	WARN_ON(ioctx->n_rdma <= 0);
1480 	atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1481 
1482 	if (opcode == SRPT_RDMA_READ_LAST) {
1483 		if (srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
1484 						SRPT_STATE_DATA_IN))
1485 			target_execute_cmd(&ioctx->cmd);
1486 		else
1487 			printk(KERN_ERR "%s[%d]: wrong state = %d\n", __func__,
1488 			       __LINE__, srpt_get_cmd_state(ioctx));
1489 	} else if (opcode == SRPT_RDMA_ABORT) {
1490 		ioctx->rdma_aborted = true;
1491 	} else {
1492 		WARN(true, "unexpected opcode %d\n", opcode);
1493 	}
1494 }
1495 
1496 /**
1497  * srpt_handle_rdma_err_comp() - Process an IB RDMA error completion.
1498  */
1499 static void srpt_handle_rdma_err_comp(struct srpt_rdma_ch *ch,
1500 				      struct srpt_send_ioctx *ioctx,
1501 				      enum srpt_opcode opcode)
1502 {
1503 	struct se_cmd *cmd;
1504 	enum srpt_command_state state;
1505 	unsigned long flags;
1506 
1507 	cmd = &ioctx->cmd;
1508 	state = srpt_get_cmd_state(ioctx);
1509 	switch (opcode) {
1510 	case SRPT_RDMA_READ_LAST:
1511 		if (ioctx->n_rdma <= 0) {
1512 			printk(KERN_ERR "Received invalid RDMA read"
1513 			       " error completion with idx %d\n",
1514 			       ioctx->ioctx.index);
1515 			break;
1516 		}
1517 		atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1518 		if (state == SRPT_STATE_NEED_DATA)
1519 			srpt_abort_cmd(ioctx);
1520 		else
1521 			printk(KERN_ERR "%s[%d]: wrong state = %d\n",
1522 			       __func__, __LINE__, state);
1523 		break;
1524 	case SRPT_RDMA_WRITE_LAST:
1525 		spin_lock_irqsave(&ioctx->cmd.t_state_lock, flags);
1526 		ioctx->cmd.transport_state |= CMD_T_LUN_STOP;
1527 		spin_unlock_irqrestore(&ioctx->cmd.t_state_lock, flags);
1528 		break;
1529 	default:
1530 		printk(KERN_ERR "%s[%d]: opcode = %u\n", __func__,
1531 		       __LINE__, opcode);
1532 		break;
1533 	}
1534 }
1535 
1536 /**
1537  * srpt_build_cmd_rsp() - Build an SRP_RSP response.
1538  * @ch: RDMA channel through which the request has been received.
1539  * @ioctx: I/O context associated with the SRP_CMD request. The response will
1540  *   be built in the buffer ioctx->buf points at and hence this function will
1541  *   overwrite the request data.
1542  * @tag: tag of the request for which this response is being generated.
1543  * @status: value for the STATUS field of the SRP_RSP information unit.
1544  *
1545  * Returns the size in bytes of the SRP_RSP response.
1546  *
1547  * An SRP_RSP response contains a SCSI status or service response. See also
1548  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1549  * response. See also SPC-2 for more information about sense data.
1550  */
1551 static int srpt_build_cmd_rsp(struct srpt_rdma_ch *ch,
1552 			      struct srpt_send_ioctx *ioctx, u64 tag,
1553 			      int status)
1554 {
1555 	struct srp_rsp *srp_rsp;
1556 	const u8 *sense_data;
1557 	int sense_data_len, max_sense_len;
1558 
1559 	/*
1560 	 * The lowest bit of all SAM-3 status codes is zero (see also
1561 	 * paragraph 5.3 in SAM-3).
1562 	 */
1563 	WARN_ON(status & 1);
1564 
1565 	srp_rsp = ioctx->ioctx.buf;
1566 	BUG_ON(!srp_rsp);
1567 
1568 	sense_data = ioctx->sense_data;
1569 	sense_data_len = ioctx->cmd.scsi_sense_length;
1570 	WARN_ON(sense_data_len > sizeof(ioctx->sense_data));
1571 
1572 	memset(srp_rsp, 0, sizeof *srp_rsp);
1573 	srp_rsp->opcode = SRP_RSP;
1574 	srp_rsp->req_lim_delta =
1575 		__constant_cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
1576 	srp_rsp->tag = tag;
1577 	srp_rsp->status = status;
1578 
1579 	if (sense_data_len) {
1580 		BUILD_BUG_ON(MIN_MAX_RSP_SIZE <= sizeof(*srp_rsp));
1581 		max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);
1582 		if (sense_data_len > max_sense_len) {
1583 			printk(KERN_WARNING "truncated sense data from %d to %d"
1584 			       " bytes\n", sense_data_len, max_sense_len);
1585 			sense_data_len = max_sense_len;
1586 		}
1587 
1588 		srp_rsp->flags |= SRP_RSP_FLAG_SNSVALID;
1589 		srp_rsp->sense_data_len = cpu_to_be32(sense_data_len);
1590 		memcpy(srp_rsp + 1, sense_data, sense_data_len);
1591 	}
1592 
1593 	return sizeof(*srp_rsp) + sense_data_len;
1594 }
1595 
1596 /**
1597  * srpt_build_tskmgmt_rsp() - Build a task management response.
1598  * @ch:       RDMA channel through which the request has been received.
1599  * @ioctx:    I/O context in which the SRP_RSP response will be built.
1600  * @rsp_code: RSP_CODE that will be stored in the response.
1601  * @tag:      Tag of the request for which this response is being generated.
1602  *
1603  * Returns the size in bytes of the SRP_RSP response.
1604  *
1605  * An SRP_RSP response contains a SCSI status or service response. See also
1606  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1607  * response.
1608  */
1609 static int srpt_build_tskmgmt_rsp(struct srpt_rdma_ch *ch,
1610 				  struct srpt_send_ioctx *ioctx,
1611 				  u8 rsp_code, u64 tag)
1612 {
1613 	struct srp_rsp *srp_rsp;
1614 	int resp_data_len;
1615 	int resp_len;
1616 
1617 	resp_data_len = (rsp_code == SRP_TSK_MGMT_SUCCESS) ? 0 : 4;
1618 	resp_len = sizeof(*srp_rsp) + resp_data_len;
1619 
1620 	srp_rsp = ioctx->ioctx.buf;
1621 	BUG_ON(!srp_rsp);
1622 	memset(srp_rsp, 0, sizeof *srp_rsp);
1623 
1624 	srp_rsp->opcode = SRP_RSP;
1625 	srp_rsp->req_lim_delta = __constant_cpu_to_be32(1
1626 				    + atomic_xchg(&ch->req_lim_delta, 0));
1627 	srp_rsp->tag = tag;
1628 
1629 	if (rsp_code != SRP_TSK_MGMT_SUCCESS) {
1630 		srp_rsp->flags |= SRP_RSP_FLAG_RSPVALID;
1631 		srp_rsp->resp_data_len = cpu_to_be32(resp_data_len);
1632 		srp_rsp->data[3] = rsp_code;
1633 	}
1634 
1635 	return resp_len;
1636 }
1637 
1638 #define NO_SUCH_LUN ((uint64_t)-1LL)
1639 
1640 /*
1641  * SCSI LUN addressing method. See also SAM-2 and the section about
1642  * eight byte LUNs.
1643  */
1644 enum scsi_lun_addr_method {
1645 	SCSI_LUN_ADDR_METHOD_PERIPHERAL   = 0,
1646 	SCSI_LUN_ADDR_METHOD_FLAT         = 1,
1647 	SCSI_LUN_ADDR_METHOD_LUN          = 2,
1648 	SCSI_LUN_ADDR_METHOD_EXTENDED_LUN = 3,
1649 };
1650 
1651 /*
1652  * srpt_unpack_lun() - Convert from network LUN to linear LUN.
1653  *
1654  * Convert an 2-byte, 4-byte, 6-byte or 8-byte LUN structure in network byte
1655  * order (big endian) to a linear LUN. Supports three LUN addressing methods:
1656  * peripheral, flat and logical unit. See also SAM-2, section 4.9.4 (page 40).
1657  */
1658 static uint64_t srpt_unpack_lun(const uint8_t *lun, int len)
1659 {
1660 	uint64_t res = NO_SUCH_LUN;
1661 	int addressing_method;
1662 
1663 	if (unlikely(len < 2)) {
1664 		printk(KERN_ERR "Illegal LUN length %d, expected 2 bytes or "
1665 		       "more", len);
1666 		goto out;
1667 	}
1668 
1669 	switch (len) {
1670 	case 8:
1671 		if ((*((__be64 *)lun) &
1672 		     __constant_cpu_to_be64(0x0000FFFFFFFFFFFFLL)) != 0)
1673 			goto out_err;
1674 		break;
1675 	case 4:
1676 		if (*((__be16 *)&lun[2]) != 0)
1677 			goto out_err;
1678 		break;
1679 	case 6:
1680 		if (*((__be32 *)&lun[2]) != 0)
1681 			goto out_err;
1682 		break;
1683 	case 2:
1684 		break;
1685 	default:
1686 		goto out_err;
1687 	}
1688 
1689 	addressing_method = (*lun) >> 6; /* highest two bits of byte 0 */
1690 	switch (addressing_method) {
1691 	case SCSI_LUN_ADDR_METHOD_PERIPHERAL:
1692 	case SCSI_LUN_ADDR_METHOD_FLAT:
1693 	case SCSI_LUN_ADDR_METHOD_LUN:
1694 		res = *(lun + 1) | (((*lun) & 0x3f) << 8);
1695 		break;
1696 
1697 	case SCSI_LUN_ADDR_METHOD_EXTENDED_LUN:
1698 	default:
1699 		printk(KERN_ERR "Unimplemented LUN addressing method %u",
1700 		       addressing_method);
1701 		break;
1702 	}
1703 
1704 out:
1705 	return res;
1706 
1707 out_err:
1708 	printk(KERN_ERR "Support for multi-level LUNs has not yet been"
1709 	       " implemented");
1710 	goto out;
1711 }
1712 
1713 static int srpt_check_stop_free(struct se_cmd *cmd)
1714 {
1715 	struct srpt_send_ioctx *ioctx;
1716 
1717 	ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
1718 	return kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1719 }
1720 
1721 /**
1722  * srpt_handle_cmd() - Process SRP_CMD.
1723  */
1724 static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
1725 			   struct srpt_recv_ioctx *recv_ioctx,
1726 			   struct srpt_send_ioctx *send_ioctx)
1727 {
1728 	struct se_cmd *cmd;
1729 	struct srp_cmd *srp_cmd;
1730 	uint64_t unpacked_lun;
1731 	u64 data_len;
1732 	enum dma_data_direction dir;
1733 	int ret;
1734 
1735 	BUG_ON(!send_ioctx);
1736 
1737 	srp_cmd = recv_ioctx->ioctx.buf;
1738 	kref_get(&send_ioctx->kref);
1739 	cmd = &send_ioctx->cmd;
1740 	send_ioctx->tag = srp_cmd->tag;
1741 
1742 	switch (srp_cmd->task_attr) {
1743 	case SRP_CMD_SIMPLE_Q:
1744 		cmd->sam_task_attr = MSG_SIMPLE_TAG;
1745 		break;
1746 	case SRP_CMD_ORDERED_Q:
1747 	default:
1748 		cmd->sam_task_attr = MSG_ORDERED_TAG;
1749 		break;
1750 	case SRP_CMD_HEAD_OF_Q:
1751 		cmd->sam_task_attr = MSG_HEAD_TAG;
1752 		break;
1753 	case SRP_CMD_ACA:
1754 		cmd->sam_task_attr = MSG_ACA_TAG;
1755 		break;
1756 	}
1757 
1758 	ret = srpt_get_desc_tbl(send_ioctx, srp_cmd, &dir, &data_len);
1759 	if (ret) {
1760 		printk(KERN_ERR "0x%llx: parsing SRP descriptor table failed.\n",
1761 		       srp_cmd->tag);
1762 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1763 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1764 		kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
1765 		goto send_sense;
1766 	}
1767 
1768 	cmd->data_length = data_len;
1769 	cmd->data_direction = dir;
1770 	unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_cmd->lun,
1771 				       sizeof(srp_cmd->lun));
1772 	if (transport_lookup_cmd_lun(cmd, unpacked_lun) < 0) {
1773 		kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
1774 		goto send_sense;
1775 	}
1776 	ret = target_setup_cmd_from_cdb(cmd, srp_cmd->cdb);
1777 	if (ret < 0) {
1778 		kref_put(&send_ioctx->kref, srpt_put_send_ioctx_kref);
1779 		if (cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT) {
1780 			srpt_queue_status(cmd);
1781 			return 0;
1782 		} else
1783 			goto send_sense;
1784 	}
1785 
1786 	transport_handle_cdb_direct(cmd);
1787 	return 0;
1788 
1789 send_sense:
1790 	transport_send_check_condition_and_sense(cmd, cmd->scsi_sense_reason,
1791 						 0);
1792 	return -1;
1793 }
1794 
1795 /**
1796  * srpt_rx_mgmt_fn_tag() - Process a task management function by tag.
1797  * @ch: RDMA channel of the task management request.
1798  * @fn: Task management function to perform.
1799  * @req_tag: Tag of the SRP task management request.
1800  * @mgmt_ioctx: I/O context of the task management request.
1801  *
1802  * Returns zero if the target core will process the task management
1803  * request asynchronously.
1804  *
1805  * Note: It is assumed that the initiator serializes tag-based task management
1806  * requests.
1807  */
1808 static int srpt_rx_mgmt_fn_tag(struct srpt_send_ioctx *ioctx, u64 tag)
1809 {
1810 	struct srpt_device *sdev;
1811 	struct srpt_rdma_ch *ch;
1812 	struct srpt_send_ioctx *target;
1813 	int ret, i;
1814 
1815 	ret = -EINVAL;
1816 	ch = ioctx->ch;
1817 	BUG_ON(!ch);
1818 	BUG_ON(!ch->sport);
1819 	sdev = ch->sport->sdev;
1820 	BUG_ON(!sdev);
1821 	spin_lock_irq(&sdev->spinlock);
1822 	for (i = 0; i < ch->rq_size; ++i) {
1823 		target = ch->ioctx_ring[i];
1824 		if (target->cmd.se_lun == ioctx->cmd.se_lun &&
1825 		    target->tag == tag &&
1826 		    srpt_get_cmd_state(target) != SRPT_STATE_DONE) {
1827 			ret = 0;
1828 			/* now let the target core abort &target->cmd; */
1829 			break;
1830 		}
1831 	}
1832 	spin_unlock_irq(&sdev->spinlock);
1833 	return ret;
1834 }
1835 
1836 static int srp_tmr_to_tcm(int fn)
1837 {
1838 	switch (fn) {
1839 	case SRP_TSK_ABORT_TASK:
1840 		return TMR_ABORT_TASK;
1841 	case SRP_TSK_ABORT_TASK_SET:
1842 		return TMR_ABORT_TASK_SET;
1843 	case SRP_TSK_CLEAR_TASK_SET:
1844 		return TMR_CLEAR_TASK_SET;
1845 	case SRP_TSK_LUN_RESET:
1846 		return TMR_LUN_RESET;
1847 	case SRP_TSK_CLEAR_ACA:
1848 		return TMR_CLEAR_ACA;
1849 	default:
1850 		return -1;
1851 	}
1852 }
1853 
1854 /**
1855  * srpt_handle_tsk_mgmt() - Process an SRP_TSK_MGMT information unit.
1856  *
1857  * Returns 0 if and only if the request will be processed by the target core.
1858  *
1859  * For more information about SRP_TSK_MGMT information units, see also section
1860  * 6.7 in the SRP r16a document.
1861  */
1862 static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
1863 				 struct srpt_recv_ioctx *recv_ioctx,
1864 				 struct srpt_send_ioctx *send_ioctx)
1865 {
1866 	struct srp_tsk_mgmt *srp_tsk;
1867 	struct se_cmd *cmd;
1868 	uint64_t unpacked_lun;
1869 	int tcm_tmr;
1870 	int res;
1871 
1872 	BUG_ON(!send_ioctx);
1873 
1874 	srp_tsk = recv_ioctx->ioctx.buf;
1875 	cmd = &send_ioctx->cmd;
1876 
1877 	pr_debug("recv tsk_mgmt fn %d for task_tag %lld and cmd tag %lld"
1878 		 " cm_id %p sess %p\n", srp_tsk->tsk_mgmt_func,
1879 		 srp_tsk->task_tag, srp_tsk->tag, ch->cm_id, ch->sess);
1880 
1881 	srpt_set_cmd_state(send_ioctx, SRPT_STATE_MGMT);
1882 	send_ioctx->tag = srp_tsk->tag;
1883 	tcm_tmr = srp_tmr_to_tcm(srp_tsk->tsk_mgmt_func);
1884 	if (tcm_tmr < 0) {
1885 		send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1886 		send_ioctx->cmd.se_tmr_req->response =
1887 			TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
1888 		goto process_tmr;
1889 	}
1890 	res = core_tmr_alloc_req(cmd, NULL, tcm_tmr, GFP_KERNEL);
1891 	if (res < 0) {
1892 		send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1893 		send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
1894 		goto process_tmr;
1895 	}
1896 
1897 	unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_tsk->lun,
1898 				       sizeof(srp_tsk->lun));
1899 	res = transport_lookup_tmr_lun(&send_ioctx->cmd, unpacked_lun);
1900 	if (res) {
1901 		pr_debug("rejecting TMR for LUN %lld\n", unpacked_lun);
1902 		send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1903 		send_ioctx->cmd.se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1904 		goto process_tmr;
1905 	}
1906 
1907 	if (srp_tsk->tsk_mgmt_func == SRP_TSK_ABORT_TASK)
1908 		srpt_rx_mgmt_fn_tag(send_ioctx, srp_tsk->task_tag);
1909 
1910 process_tmr:
1911 	kref_get(&send_ioctx->kref);
1912 	if (!(send_ioctx->cmd.se_cmd_flags & SCF_SCSI_CDB_EXCEPTION))
1913 		transport_generic_handle_tmr(&send_ioctx->cmd);
1914 	else
1915 		transport_send_check_condition_and_sense(cmd,
1916 						cmd->scsi_sense_reason, 0);
1917 
1918 }
1919 
1920 /**
1921  * srpt_handle_new_iu() - Process a newly received information unit.
1922  * @ch:    RDMA channel through which the information unit has been received.
1923  * @ioctx: SRPT I/O context associated with the information unit.
1924  */
1925 static void srpt_handle_new_iu(struct srpt_rdma_ch *ch,
1926 			       struct srpt_recv_ioctx *recv_ioctx,
1927 			       struct srpt_send_ioctx *send_ioctx)
1928 {
1929 	struct srp_cmd *srp_cmd;
1930 	enum rdma_ch_state ch_state;
1931 
1932 	BUG_ON(!ch);
1933 	BUG_ON(!recv_ioctx);
1934 
1935 	ib_dma_sync_single_for_cpu(ch->sport->sdev->device,
1936 				   recv_ioctx->ioctx.dma, srp_max_req_size,
1937 				   DMA_FROM_DEVICE);
1938 
1939 	ch_state = srpt_get_ch_state(ch);
1940 	if (unlikely(ch_state == CH_CONNECTING)) {
1941 		list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list);
1942 		goto out;
1943 	}
1944 
1945 	if (unlikely(ch_state != CH_LIVE))
1946 		goto out;
1947 
1948 	srp_cmd = recv_ioctx->ioctx.buf;
1949 	if (srp_cmd->opcode == SRP_CMD || srp_cmd->opcode == SRP_TSK_MGMT) {
1950 		if (!send_ioctx)
1951 			send_ioctx = srpt_get_send_ioctx(ch);
1952 		if (unlikely(!send_ioctx)) {
1953 			list_add_tail(&recv_ioctx->wait_list,
1954 				      &ch->cmd_wait_list);
1955 			goto out;
1956 		}
1957 	}
1958 
1959 	transport_init_se_cmd(&send_ioctx->cmd, &srpt_target->tf_ops, ch->sess,
1960 			      0, DMA_NONE, MSG_SIMPLE_TAG,
1961 			      send_ioctx->sense_data);
1962 
1963 	switch (srp_cmd->opcode) {
1964 	case SRP_CMD:
1965 		srpt_handle_cmd(ch, recv_ioctx, send_ioctx);
1966 		break;
1967 	case SRP_TSK_MGMT:
1968 		srpt_handle_tsk_mgmt(ch, recv_ioctx, send_ioctx);
1969 		break;
1970 	case SRP_I_LOGOUT:
1971 		printk(KERN_ERR "Not yet implemented: SRP_I_LOGOUT\n");
1972 		break;
1973 	case SRP_CRED_RSP:
1974 		pr_debug("received SRP_CRED_RSP\n");
1975 		break;
1976 	case SRP_AER_RSP:
1977 		pr_debug("received SRP_AER_RSP\n");
1978 		break;
1979 	case SRP_RSP:
1980 		printk(KERN_ERR "Received SRP_RSP\n");
1981 		break;
1982 	default:
1983 		printk(KERN_ERR "received IU with unknown opcode 0x%x\n",
1984 		       srp_cmd->opcode);
1985 		break;
1986 	}
1987 
1988 	srpt_post_recv(ch->sport->sdev, recv_ioctx);
1989 out:
1990 	return;
1991 }
1992 
1993 static void srpt_process_rcv_completion(struct ib_cq *cq,
1994 					struct srpt_rdma_ch *ch,
1995 					struct ib_wc *wc)
1996 {
1997 	struct srpt_device *sdev = ch->sport->sdev;
1998 	struct srpt_recv_ioctx *ioctx;
1999 	u32 index;
2000 
2001 	index = idx_from_wr_id(wc->wr_id);
2002 	if (wc->status == IB_WC_SUCCESS) {
2003 		int req_lim;
2004 
2005 		req_lim = atomic_dec_return(&ch->req_lim);
2006 		if (unlikely(req_lim < 0))
2007 			printk(KERN_ERR "req_lim = %d < 0\n", req_lim);
2008 		ioctx = sdev->ioctx_ring[index];
2009 		srpt_handle_new_iu(ch, ioctx, NULL);
2010 	} else {
2011 		printk(KERN_INFO "receiving failed for idx %u with status %d\n",
2012 		       index, wc->status);
2013 	}
2014 }
2015 
2016 /**
2017  * srpt_process_send_completion() - Process an IB send completion.
2018  *
2019  * Note: Although this has not yet been observed during tests, at least in
2020  * theory it is possible that the srpt_get_send_ioctx() call invoked by
2021  * srpt_handle_new_iu() fails. This is possible because the req_lim_delta
2022  * value in each response is set to one, and it is possible that this response
2023  * makes the initiator send a new request before the send completion for that
2024  * response has been processed. This could e.g. happen if the call to
2025  * srpt_put_send_iotcx() is delayed because of a higher priority interrupt or
2026  * if IB retransmission causes generation of the send completion to be
2027  * delayed. Incoming information units for which srpt_get_send_ioctx() fails
2028  * are queued on cmd_wait_list. The code below processes these delayed
2029  * requests one at a time.
2030  */
2031 static void srpt_process_send_completion(struct ib_cq *cq,
2032 					 struct srpt_rdma_ch *ch,
2033 					 struct ib_wc *wc)
2034 {
2035 	struct srpt_send_ioctx *send_ioctx;
2036 	uint32_t index;
2037 	enum srpt_opcode opcode;
2038 
2039 	index = idx_from_wr_id(wc->wr_id);
2040 	opcode = opcode_from_wr_id(wc->wr_id);
2041 	send_ioctx = ch->ioctx_ring[index];
2042 	if (wc->status == IB_WC_SUCCESS) {
2043 		if (opcode == SRPT_SEND)
2044 			srpt_handle_send_comp(ch, send_ioctx);
2045 		else {
2046 			WARN_ON(opcode != SRPT_RDMA_ABORT &&
2047 				wc->opcode != IB_WC_RDMA_READ);
2048 			srpt_handle_rdma_comp(ch, send_ioctx, opcode);
2049 		}
2050 	} else {
2051 		if (opcode == SRPT_SEND) {
2052 			printk(KERN_INFO "sending response for idx %u failed"
2053 			       " with status %d\n", index, wc->status);
2054 			srpt_handle_send_err_comp(ch, wc->wr_id);
2055 		} else if (opcode != SRPT_RDMA_MID) {
2056 			printk(KERN_INFO "RDMA t %d for idx %u failed with"
2057 				" status %d", opcode, index, wc->status);
2058 			srpt_handle_rdma_err_comp(ch, send_ioctx, opcode);
2059 		}
2060 	}
2061 
2062 	while (unlikely(opcode == SRPT_SEND
2063 			&& !list_empty(&ch->cmd_wait_list)
2064 			&& srpt_get_ch_state(ch) == CH_LIVE
2065 			&& (send_ioctx = srpt_get_send_ioctx(ch)) != NULL)) {
2066 		struct srpt_recv_ioctx *recv_ioctx;
2067 
2068 		recv_ioctx = list_first_entry(&ch->cmd_wait_list,
2069 					      struct srpt_recv_ioctx,
2070 					      wait_list);
2071 		list_del(&recv_ioctx->wait_list);
2072 		srpt_handle_new_iu(ch, recv_ioctx, send_ioctx);
2073 	}
2074 }
2075 
2076 static void srpt_process_completion(struct ib_cq *cq, struct srpt_rdma_ch *ch)
2077 {
2078 	struct ib_wc *const wc = ch->wc;
2079 	int i, n;
2080 
2081 	WARN_ON(cq != ch->cq);
2082 
2083 	ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
2084 	while ((n = ib_poll_cq(cq, ARRAY_SIZE(ch->wc), wc)) > 0) {
2085 		for (i = 0; i < n; i++) {
2086 			if (opcode_from_wr_id(wc[i].wr_id) == SRPT_RECV)
2087 				srpt_process_rcv_completion(cq, ch, &wc[i]);
2088 			else
2089 				srpt_process_send_completion(cq, ch, &wc[i]);
2090 		}
2091 	}
2092 }
2093 
2094 /**
2095  * srpt_completion() - IB completion queue callback function.
2096  *
2097  * Notes:
2098  * - It is guaranteed that a completion handler will never be invoked
2099  *   concurrently on two different CPUs for the same completion queue. See also
2100  *   Documentation/infiniband/core_locking.txt and the implementation of
2101  *   handle_edge_irq() in kernel/irq/chip.c.
2102  * - When threaded IRQs are enabled, completion handlers are invoked in thread
2103  *   context instead of interrupt context.
2104  */
2105 static void srpt_completion(struct ib_cq *cq, void *ctx)
2106 {
2107 	struct srpt_rdma_ch *ch = ctx;
2108 
2109 	wake_up_interruptible(&ch->wait_queue);
2110 }
2111 
2112 static int srpt_compl_thread(void *arg)
2113 {
2114 	struct srpt_rdma_ch *ch;
2115 
2116 	/* Hibernation / freezing of the SRPT kernel thread is not supported. */
2117 	current->flags |= PF_NOFREEZE;
2118 
2119 	ch = arg;
2120 	BUG_ON(!ch);
2121 	printk(KERN_INFO "Session %s: kernel thread %s (PID %d) started\n",
2122 	       ch->sess_name, ch->thread->comm, current->pid);
2123 	while (!kthread_should_stop()) {
2124 		wait_event_interruptible(ch->wait_queue,
2125 			(srpt_process_completion(ch->cq, ch),
2126 			 kthread_should_stop()));
2127 	}
2128 	printk(KERN_INFO "Session %s: kernel thread %s (PID %d) stopped\n",
2129 	       ch->sess_name, ch->thread->comm, current->pid);
2130 	return 0;
2131 }
2132 
2133 /**
2134  * srpt_create_ch_ib() - Create receive and send completion queues.
2135  */
2136 static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
2137 {
2138 	struct ib_qp_init_attr *qp_init;
2139 	struct srpt_port *sport = ch->sport;
2140 	struct srpt_device *sdev = sport->sdev;
2141 	u32 srp_sq_size = sport->port_attrib.srp_sq_size;
2142 	int ret;
2143 
2144 	WARN_ON(ch->rq_size < 1);
2145 
2146 	ret = -ENOMEM;
2147 	qp_init = kzalloc(sizeof *qp_init, GFP_KERNEL);
2148 	if (!qp_init)
2149 		goto out;
2150 
2151 	ch->cq = ib_create_cq(sdev->device, srpt_completion, NULL, ch,
2152 			      ch->rq_size + srp_sq_size, 0);
2153 	if (IS_ERR(ch->cq)) {
2154 		ret = PTR_ERR(ch->cq);
2155 		printk(KERN_ERR "failed to create CQ cqe= %d ret= %d\n",
2156 		       ch->rq_size + srp_sq_size, ret);
2157 		goto out;
2158 	}
2159 
2160 	qp_init->qp_context = (void *)ch;
2161 	qp_init->event_handler
2162 		= (void(*)(struct ib_event *, void*))srpt_qp_event;
2163 	qp_init->send_cq = ch->cq;
2164 	qp_init->recv_cq = ch->cq;
2165 	qp_init->srq = sdev->srq;
2166 	qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
2167 	qp_init->qp_type = IB_QPT_RC;
2168 	qp_init->cap.max_send_wr = srp_sq_size;
2169 	qp_init->cap.max_send_sge = SRPT_DEF_SG_PER_WQE;
2170 
2171 	ch->qp = ib_create_qp(sdev->pd, qp_init);
2172 	if (IS_ERR(ch->qp)) {
2173 		ret = PTR_ERR(ch->qp);
2174 		printk(KERN_ERR "failed to create_qp ret= %d\n", ret);
2175 		goto err_destroy_cq;
2176 	}
2177 
2178 	atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
2179 
2180 	pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
2181 		 __func__, ch->cq->cqe, qp_init->cap.max_send_sge,
2182 		 qp_init->cap.max_send_wr, ch->cm_id);
2183 
2184 	ret = srpt_init_ch_qp(ch, ch->qp);
2185 	if (ret)
2186 		goto err_destroy_qp;
2187 
2188 	init_waitqueue_head(&ch->wait_queue);
2189 
2190 	pr_debug("creating thread for session %s\n", ch->sess_name);
2191 
2192 	ch->thread = kthread_run(srpt_compl_thread, ch, "ib_srpt_compl");
2193 	if (IS_ERR(ch->thread)) {
2194 		printk(KERN_ERR "failed to create kernel thread %ld\n",
2195 		       PTR_ERR(ch->thread));
2196 		ch->thread = NULL;
2197 		goto err_destroy_qp;
2198 	}
2199 
2200 out:
2201 	kfree(qp_init);
2202 	return ret;
2203 
2204 err_destroy_qp:
2205 	ib_destroy_qp(ch->qp);
2206 err_destroy_cq:
2207 	ib_destroy_cq(ch->cq);
2208 	goto out;
2209 }
2210 
2211 static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
2212 {
2213 	if (ch->thread)
2214 		kthread_stop(ch->thread);
2215 
2216 	ib_destroy_qp(ch->qp);
2217 	ib_destroy_cq(ch->cq);
2218 }
2219 
2220 /**
2221  * __srpt_close_ch() - Close an RDMA channel by setting the QP error state.
2222  *
2223  * Reset the QP and make sure all resources associated with the channel will
2224  * be deallocated at an appropriate time.
2225  *
2226  * Note: The caller must hold ch->sport->sdev->spinlock.
2227  */
2228 static void __srpt_close_ch(struct srpt_rdma_ch *ch)
2229 {
2230 	struct srpt_device *sdev;
2231 	enum rdma_ch_state prev_state;
2232 	unsigned long flags;
2233 
2234 	sdev = ch->sport->sdev;
2235 
2236 	spin_lock_irqsave(&ch->spinlock, flags);
2237 	prev_state = ch->state;
2238 	switch (prev_state) {
2239 	case CH_CONNECTING:
2240 	case CH_LIVE:
2241 		ch->state = CH_DISCONNECTING;
2242 		break;
2243 	default:
2244 		break;
2245 	}
2246 	spin_unlock_irqrestore(&ch->spinlock, flags);
2247 
2248 	switch (prev_state) {
2249 	case CH_CONNECTING:
2250 		ib_send_cm_rej(ch->cm_id, IB_CM_REJ_NO_RESOURCES, NULL, 0,
2251 			       NULL, 0);
2252 		/* fall through */
2253 	case CH_LIVE:
2254 		if (ib_send_cm_dreq(ch->cm_id, NULL, 0) < 0)
2255 			printk(KERN_ERR "sending CM DREQ failed.\n");
2256 		break;
2257 	case CH_DISCONNECTING:
2258 		break;
2259 	case CH_DRAINING:
2260 	case CH_RELEASING:
2261 		break;
2262 	}
2263 }
2264 
2265 /**
2266  * srpt_close_ch() - Close an RDMA channel.
2267  */
2268 static void srpt_close_ch(struct srpt_rdma_ch *ch)
2269 {
2270 	struct srpt_device *sdev;
2271 
2272 	sdev = ch->sport->sdev;
2273 	spin_lock_irq(&sdev->spinlock);
2274 	__srpt_close_ch(ch);
2275 	spin_unlock_irq(&sdev->spinlock);
2276 }
2277 
2278 /**
2279  * srpt_drain_channel() - Drain a channel by resetting the IB queue pair.
2280  * @cm_id: Pointer to the CM ID of the channel to be drained.
2281  *
2282  * Note: Must be called from inside srpt_cm_handler to avoid a race between
2283  * accessing sdev->spinlock and the call to kfree(sdev) in srpt_remove_one()
2284  * (the caller of srpt_cm_handler holds the cm_id spinlock; srpt_remove_one()
2285  * waits until all target sessions for the associated IB device have been
2286  * unregistered and target session registration involves a call to
2287  * ib_destroy_cm_id(), which locks the cm_id spinlock and hence waits until
2288  * this function has finished).
2289  */
2290 static void srpt_drain_channel(struct ib_cm_id *cm_id)
2291 {
2292 	struct srpt_device *sdev;
2293 	struct srpt_rdma_ch *ch;
2294 	int ret;
2295 	bool do_reset = false;
2296 
2297 	WARN_ON_ONCE(irqs_disabled());
2298 
2299 	sdev = cm_id->context;
2300 	BUG_ON(!sdev);
2301 	spin_lock_irq(&sdev->spinlock);
2302 	list_for_each_entry(ch, &sdev->rch_list, list) {
2303 		if (ch->cm_id == cm_id) {
2304 			do_reset = srpt_test_and_set_ch_state(ch,
2305 					CH_CONNECTING, CH_DRAINING) ||
2306 				   srpt_test_and_set_ch_state(ch,
2307 					CH_LIVE, CH_DRAINING) ||
2308 				   srpt_test_and_set_ch_state(ch,
2309 					CH_DISCONNECTING, CH_DRAINING);
2310 			break;
2311 		}
2312 	}
2313 	spin_unlock_irq(&sdev->spinlock);
2314 
2315 	if (do_reset) {
2316 		ret = srpt_ch_qp_err(ch);
2317 		if (ret < 0)
2318 			printk(KERN_ERR "Setting queue pair in error state"
2319 			       " failed: %d\n", ret);
2320 	}
2321 }
2322 
2323 /**
2324  * srpt_find_channel() - Look up an RDMA channel.
2325  * @cm_id: Pointer to the CM ID of the channel to be looked up.
2326  *
2327  * Return NULL if no matching RDMA channel has been found.
2328  */
2329 static struct srpt_rdma_ch *srpt_find_channel(struct srpt_device *sdev,
2330 					      struct ib_cm_id *cm_id)
2331 {
2332 	struct srpt_rdma_ch *ch;
2333 	bool found;
2334 
2335 	WARN_ON_ONCE(irqs_disabled());
2336 	BUG_ON(!sdev);
2337 
2338 	found = false;
2339 	spin_lock_irq(&sdev->spinlock);
2340 	list_for_each_entry(ch, &sdev->rch_list, list) {
2341 		if (ch->cm_id == cm_id) {
2342 			found = true;
2343 			break;
2344 		}
2345 	}
2346 	spin_unlock_irq(&sdev->spinlock);
2347 
2348 	return found ? ch : NULL;
2349 }
2350 
2351 /**
2352  * srpt_release_channel() - Release channel resources.
2353  *
2354  * Schedules the actual release because:
2355  * - Calling the ib_destroy_cm_id() call from inside an IB CM callback would
2356  *   trigger a deadlock.
2357  * - It is not safe to call TCM transport_* functions from interrupt context.
2358  */
2359 static void srpt_release_channel(struct srpt_rdma_ch *ch)
2360 {
2361 	schedule_work(&ch->release_work);
2362 }
2363 
2364 static void srpt_release_channel_work(struct work_struct *w)
2365 {
2366 	struct srpt_rdma_ch *ch;
2367 	struct srpt_device *sdev;
2368 
2369 	ch = container_of(w, struct srpt_rdma_ch, release_work);
2370 	pr_debug("ch = %p; ch->sess = %p; release_done = %p\n", ch, ch->sess,
2371 		 ch->release_done);
2372 
2373 	sdev = ch->sport->sdev;
2374 	BUG_ON(!sdev);
2375 
2376 	transport_deregister_session_configfs(ch->sess);
2377 	transport_deregister_session(ch->sess);
2378 	ch->sess = NULL;
2379 
2380 	srpt_destroy_ch_ib(ch);
2381 
2382 	srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2383 			     ch->sport->sdev, ch->rq_size,
2384 			     ch->rsp_size, DMA_TO_DEVICE);
2385 
2386 	spin_lock_irq(&sdev->spinlock);
2387 	list_del(&ch->list);
2388 	spin_unlock_irq(&sdev->spinlock);
2389 
2390 	ib_destroy_cm_id(ch->cm_id);
2391 
2392 	if (ch->release_done)
2393 		complete(ch->release_done);
2394 
2395 	wake_up(&sdev->ch_releaseQ);
2396 
2397 	kfree(ch);
2398 }
2399 
2400 static struct srpt_node_acl *__srpt_lookup_acl(struct srpt_port *sport,
2401 					       u8 i_port_id[16])
2402 {
2403 	struct srpt_node_acl *nacl;
2404 
2405 	list_for_each_entry(nacl, &sport->port_acl_list, list)
2406 		if (memcmp(nacl->i_port_id, i_port_id,
2407 			   sizeof(nacl->i_port_id)) == 0)
2408 			return nacl;
2409 
2410 	return NULL;
2411 }
2412 
2413 static struct srpt_node_acl *srpt_lookup_acl(struct srpt_port *sport,
2414 					     u8 i_port_id[16])
2415 {
2416 	struct srpt_node_acl *nacl;
2417 
2418 	spin_lock_irq(&sport->port_acl_lock);
2419 	nacl = __srpt_lookup_acl(sport, i_port_id);
2420 	spin_unlock_irq(&sport->port_acl_lock);
2421 
2422 	return nacl;
2423 }
2424 
2425 /**
2426  * srpt_cm_req_recv() - Process the event IB_CM_REQ_RECEIVED.
2427  *
2428  * Ownership of the cm_id is transferred to the target session if this
2429  * functions returns zero. Otherwise the caller remains the owner of cm_id.
2430  */
2431 static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
2432 			    struct ib_cm_req_event_param *param,
2433 			    void *private_data)
2434 {
2435 	struct srpt_device *sdev = cm_id->context;
2436 	struct srpt_port *sport = &sdev->port[param->port - 1];
2437 	struct srp_login_req *req;
2438 	struct srp_login_rsp *rsp;
2439 	struct srp_login_rej *rej;
2440 	struct ib_cm_rep_param *rep_param;
2441 	struct srpt_rdma_ch *ch, *tmp_ch;
2442 	struct srpt_node_acl *nacl;
2443 	u32 it_iu_len;
2444 	int i;
2445 	int ret = 0;
2446 
2447 	WARN_ON_ONCE(irqs_disabled());
2448 
2449 	if (WARN_ON(!sdev || !private_data))
2450 		return -EINVAL;
2451 
2452 	req = (struct srp_login_req *)private_data;
2453 
2454 	it_iu_len = be32_to_cpu(req->req_it_iu_len);
2455 
2456 	printk(KERN_INFO "Received SRP_LOGIN_REQ with i_port_id 0x%llx:0x%llx,"
2457 	       " t_port_id 0x%llx:0x%llx and it_iu_len %d on port %d"
2458 	       " (guid=0x%llx:0x%llx)\n",
2459 	       be64_to_cpu(*(__be64 *)&req->initiator_port_id[0]),
2460 	       be64_to_cpu(*(__be64 *)&req->initiator_port_id[8]),
2461 	       be64_to_cpu(*(__be64 *)&req->target_port_id[0]),
2462 	       be64_to_cpu(*(__be64 *)&req->target_port_id[8]),
2463 	       it_iu_len,
2464 	       param->port,
2465 	       be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[0]),
2466 	       be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[8]));
2467 
2468 	rsp = kzalloc(sizeof *rsp, GFP_KERNEL);
2469 	rej = kzalloc(sizeof *rej, GFP_KERNEL);
2470 	rep_param = kzalloc(sizeof *rep_param, GFP_KERNEL);
2471 
2472 	if (!rsp || !rej || !rep_param) {
2473 		ret = -ENOMEM;
2474 		goto out;
2475 	}
2476 
2477 	if (it_iu_len > srp_max_req_size || it_iu_len < 64) {
2478 		rej->reason = __constant_cpu_to_be32(
2479 				SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE);
2480 		ret = -EINVAL;
2481 		printk(KERN_ERR "rejected SRP_LOGIN_REQ because its"
2482 		       " length (%d bytes) is out of range (%d .. %d)\n",
2483 		       it_iu_len, 64, srp_max_req_size);
2484 		goto reject;
2485 	}
2486 
2487 	if (!sport->enabled) {
2488 		rej->reason = __constant_cpu_to_be32(
2489 			     SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2490 		ret = -EINVAL;
2491 		printk(KERN_ERR "rejected SRP_LOGIN_REQ because the target port"
2492 		       " has not yet been enabled\n");
2493 		goto reject;
2494 	}
2495 
2496 	if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) {
2497 		rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_NO_CHAN;
2498 
2499 		spin_lock_irq(&sdev->spinlock);
2500 
2501 		list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list) {
2502 			if (!memcmp(ch->i_port_id, req->initiator_port_id, 16)
2503 			    && !memcmp(ch->t_port_id, req->target_port_id, 16)
2504 			    && param->port == ch->sport->port
2505 			    && param->listen_id == ch->sport->sdev->cm_id
2506 			    && ch->cm_id) {
2507 				enum rdma_ch_state ch_state;
2508 
2509 				ch_state = srpt_get_ch_state(ch);
2510 				if (ch_state != CH_CONNECTING
2511 				    && ch_state != CH_LIVE)
2512 					continue;
2513 
2514 				/* found an existing channel */
2515 				pr_debug("Found existing channel %s"
2516 					 " cm_id= %p state= %d\n",
2517 					 ch->sess_name, ch->cm_id, ch_state);
2518 
2519 				__srpt_close_ch(ch);
2520 
2521 				rsp->rsp_flags =
2522 					SRP_LOGIN_RSP_MULTICHAN_TERMINATED;
2523 			}
2524 		}
2525 
2526 		spin_unlock_irq(&sdev->spinlock);
2527 
2528 	} else
2529 		rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_MAINTAINED;
2530 
2531 	if (*(__be64 *)req->target_port_id != cpu_to_be64(srpt_service_guid)
2532 	    || *(__be64 *)(req->target_port_id + 8) !=
2533 	       cpu_to_be64(srpt_service_guid)) {
2534 		rej->reason = __constant_cpu_to_be32(
2535 				SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL);
2536 		ret = -ENOMEM;
2537 		printk(KERN_ERR "rejected SRP_LOGIN_REQ because it"
2538 		       " has an invalid target port identifier.\n");
2539 		goto reject;
2540 	}
2541 
2542 	ch = kzalloc(sizeof *ch, GFP_KERNEL);
2543 	if (!ch) {
2544 		rej->reason = __constant_cpu_to_be32(
2545 					SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2546 		printk(KERN_ERR "rejected SRP_LOGIN_REQ because no memory.\n");
2547 		ret = -ENOMEM;
2548 		goto reject;
2549 	}
2550 
2551 	INIT_WORK(&ch->release_work, srpt_release_channel_work);
2552 	memcpy(ch->i_port_id, req->initiator_port_id, 16);
2553 	memcpy(ch->t_port_id, req->target_port_id, 16);
2554 	ch->sport = &sdev->port[param->port - 1];
2555 	ch->cm_id = cm_id;
2556 	/*
2557 	 * Avoid QUEUE_FULL conditions by limiting the number of buffers used
2558 	 * for the SRP protocol to the command queue size.
2559 	 */
2560 	ch->rq_size = SRPT_RQ_SIZE;
2561 	spin_lock_init(&ch->spinlock);
2562 	ch->state = CH_CONNECTING;
2563 	INIT_LIST_HEAD(&ch->cmd_wait_list);
2564 	ch->rsp_size = ch->sport->port_attrib.srp_max_rsp_size;
2565 
2566 	ch->ioctx_ring = (struct srpt_send_ioctx **)
2567 		srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
2568 				      sizeof(*ch->ioctx_ring[0]),
2569 				      ch->rsp_size, DMA_TO_DEVICE);
2570 	if (!ch->ioctx_ring)
2571 		goto free_ch;
2572 
2573 	INIT_LIST_HEAD(&ch->free_list);
2574 	for (i = 0; i < ch->rq_size; i++) {
2575 		ch->ioctx_ring[i]->ch = ch;
2576 		list_add_tail(&ch->ioctx_ring[i]->free_list, &ch->free_list);
2577 	}
2578 
2579 	ret = srpt_create_ch_ib(ch);
2580 	if (ret) {
2581 		rej->reason = __constant_cpu_to_be32(
2582 				SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2583 		printk(KERN_ERR "rejected SRP_LOGIN_REQ because creating"
2584 		       " a new RDMA channel failed.\n");
2585 		goto free_ring;
2586 	}
2587 
2588 	ret = srpt_ch_qp_rtr(ch, ch->qp);
2589 	if (ret) {
2590 		rej->reason = __constant_cpu_to_be32(
2591 				SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2592 		printk(KERN_ERR "rejected SRP_LOGIN_REQ because enabling"
2593 		       " RTR failed (error code = %d)\n", ret);
2594 		goto destroy_ib;
2595 	}
2596 	/*
2597 	 * Use the initator port identifier as the session name.
2598 	 */
2599 	snprintf(ch->sess_name, sizeof(ch->sess_name), "0x%016llx%016llx",
2600 			be64_to_cpu(*(__be64 *)ch->i_port_id),
2601 			be64_to_cpu(*(__be64 *)(ch->i_port_id + 8)));
2602 
2603 	pr_debug("registering session %s\n", ch->sess_name);
2604 
2605 	nacl = srpt_lookup_acl(sport, ch->i_port_id);
2606 	if (!nacl) {
2607 		printk(KERN_INFO "Rejected login because no ACL has been"
2608 		       " configured yet for initiator %s.\n", ch->sess_name);
2609 		rej->reason = __constant_cpu_to_be32(
2610 				SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED);
2611 		goto destroy_ib;
2612 	}
2613 
2614 	ch->sess = transport_init_session();
2615 	if (IS_ERR(ch->sess)) {
2616 		rej->reason = __constant_cpu_to_be32(
2617 				SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2618 		pr_debug("Failed to create session\n");
2619 		goto deregister_session;
2620 	}
2621 	ch->sess->se_node_acl = &nacl->nacl;
2622 	transport_register_session(&sport->port_tpg_1, &nacl->nacl, ch->sess, ch);
2623 
2624 	pr_debug("Establish connection sess=%p name=%s cm_id=%p\n", ch->sess,
2625 		 ch->sess_name, ch->cm_id);
2626 
2627 	/* create srp_login_response */
2628 	rsp->opcode = SRP_LOGIN_RSP;
2629 	rsp->tag = req->tag;
2630 	rsp->max_it_iu_len = req->req_it_iu_len;
2631 	rsp->max_ti_iu_len = req->req_it_iu_len;
2632 	ch->max_ti_iu_len = it_iu_len;
2633 	rsp->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2634 					      | SRP_BUF_FORMAT_INDIRECT);
2635 	rsp->req_lim_delta = cpu_to_be32(ch->rq_size);
2636 	atomic_set(&ch->req_lim, ch->rq_size);
2637 	atomic_set(&ch->req_lim_delta, 0);
2638 
2639 	/* create cm reply */
2640 	rep_param->qp_num = ch->qp->qp_num;
2641 	rep_param->private_data = (void *)rsp;
2642 	rep_param->private_data_len = sizeof *rsp;
2643 	rep_param->rnr_retry_count = 7;
2644 	rep_param->flow_control = 1;
2645 	rep_param->failover_accepted = 0;
2646 	rep_param->srq = 1;
2647 	rep_param->responder_resources = 4;
2648 	rep_param->initiator_depth = 4;
2649 
2650 	ret = ib_send_cm_rep(cm_id, rep_param);
2651 	if (ret) {
2652 		printk(KERN_ERR "sending SRP_LOGIN_REQ response failed"
2653 		       " (error code = %d)\n", ret);
2654 		goto release_channel;
2655 	}
2656 
2657 	spin_lock_irq(&sdev->spinlock);
2658 	list_add_tail(&ch->list, &sdev->rch_list);
2659 	spin_unlock_irq(&sdev->spinlock);
2660 
2661 	goto out;
2662 
2663 release_channel:
2664 	srpt_set_ch_state(ch, CH_RELEASING);
2665 	transport_deregister_session_configfs(ch->sess);
2666 
2667 deregister_session:
2668 	transport_deregister_session(ch->sess);
2669 	ch->sess = NULL;
2670 
2671 destroy_ib:
2672 	srpt_destroy_ch_ib(ch);
2673 
2674 free_ring:
2675 	srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2676 			     ch->sport->sdev, ch->rq_size,
2677 			     ch->rsp_size, DMA_TO_DEVICE);
2678 free_ch:
2679 	kfree(ch);
2680 
2681 reject:
2682 	rej->opcode = SRP_LOGIN_REJ;
2683 	rej->tag = req->tag;
2684 	rej->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2685 					      | SRP_BUF_FORMAT_INDIRECT);
2686 
2687 	ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
2688 			     (void *)rej, sizeof *rej);
2689 
2690 out:
2691 	kfree(rep_param);
2692 	kfree(rsp);
2693 	kfree(rej);
2694 
2695 	return ret;
2696 }
2697 
2698 static void srpt_cm_rej_recv(struct ib_cm_id *cm_id)
2699 {
2700 	printk(KERN_INFO "Received IB REJ for cm_id %p.\n", cm_id);
2701 	srpt_drain_channel(cm_id);
2702 }
2703 
2704 /**
2705  * srpt_cm_rtu_recv() - Process an IB_CM_RTU_RECEIVED or USER_ESTABLISHED event.
2706  *
2707  * An IB_CM_RTU_RECEIVED message indicates that the connection is established
2708  * and that the recipient may begin transmitting (RTU = ready to use).
2709  */
2710 static void srpt_cm_rtu_recv(struct ib_cm_id *cm_id)
2711 {
2712 	struct srpt_rdma_ch *ch;
2713 	int ret;
2714 
2715 	ch = srpt_find_channel(cm_id->context, cm_id);
2716 	BUG_ON(!ch);
2717 
2718 	if (srpt_test_and_set_ch_state(ch, CH_CONNECTING, CH_LIVE)) {
2719 		struct srpt_recv_ioctx *ioctx, *ioctx_tmp;
2720 
2721 		ret = srpt_ch_qp_rts(ch, ch->qp);
2722 
2723 		list_for_each_entry_safe(ioctx, ioctx_tmp, &ch->cmd_wait_list,
2724 					 wait_list) {
2725 			list_del(&ioctx->wait_list);
2726 			srpt_handle_new_iu(ch, ioctx, NULL);
2727 		}
2728 		if (ret)
2729 			srpt_close_ch(ch);
2730 	}
2731 }
2732 
2733 static void srpt_cm_timewait_exit(struct ib_cm_id *cm_id)
2734 {
2735 	printk(KERN_INFO "Received IB TimeWait exit for cm_id %p.\n", cm_id);
2736 	srpt_drain_channel(cm_id);
2737 }
2738 
2739 static void srpt_cm_rep_error(struct ib_cm_id *cm_id)
2740 {
2741 	printk(KERN_INFO "Received IB REP error for cm_id %p.\n", cm_id);
2742 	srpt_drain_channel(cm_id);
2743 }
2744 
2745 /**
2746  * srpt_cm_dreq_recv() - Process reception of a DREQ message.
2747  */
2748 static void srpt_cm_dreq_recv(struct ib_cm_id *cm_id)
2749 {
2750 	struct srpt_rdma_ch *ch;
2751 	unsigned long flags;
2752 	bool send_drep = false;
2753 
2754 	ch = srpt_find_channel(cm_id->context, cm_id);
2755 	BUG_ON(!ch);
2756 
2757 	pr_debug("cm_id= %p ch->state= %d\n", cm_id, srpt_get_ch_state(ch));
2758 
2759 	spin_lock_irqsave(&ch->spinlock, flags);
2760 	switch (ch->state) {
2761 	case CH_CONNECTING:
2762 	case CH_LIVE:
2763 		send_drep = true;
2764 		ch->state = CH_DISCONNECTING;
2765 		break;
2766 	case CH_DISCONNECTING:
2767 	case CH_DRAINING:
2768 	case CH_RELEASING:
2769 		WARN(true, "unexpected channel state %d\n", ch->state);
2770 		break;
2771 	}
2772 	spin_unlock_irqrestore(&ch->spinlock, flags);
2773 
2774 	if (send_drep) {
2775 		if (ib_send_cm_drep(ch->cm_id, NULL, 0) < 0)
2776 			printk(KERN_ERR "Sending IB DREP failed.\n");
2777 		printk(KERN_INFO "Received DREQ and sent DREP for session %s.\n",
2778 		       ch->sess_name);
2779 	}
2780 }
2781 
2782 /**
2783  * srpt_cm_drep_recv() - Process reception of a DREP message.
2784  */
2785 static void srpt_cm_drep_recv(struct ib_cm_id *cm_id)
2786 {
2787 	printk(KERN_INFO "Received InfiniBand DREP message for cm_id %p.\n",
2788 	       cm_id);
2789 	srpt_drain_channel(cm_id);
2790 }
2791 
2792 /**
2793  * srpt_cm_handler() - IB connection manager callback function.
2794  *
2795  * A non-zero return value will cause the caller destroy the CM ID.
2796  *
2797  * Note: srpt_cm_handler() must only return a non-zero value when transferring
2798  * ownership of the cm_id to a channel by srpt_cm_req_recv() failed. Returning
2799  * a non-zero value in any other case will trigger a race with the
2800  * ib_destroy_cm_id() call in srpt_release_channel().
2801  */
2802 static int srpt_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
2803 {
2804 	int ret;
2805 
2806 	ret = 0;
2807 	switch (event->event) {
2808 	case IB_CM_REQ_RECEIVED:
2809 		ret = srpt_cm_req_recv(cm_id, &event->param.req_rcvd,
2810 				       event->private_data);
2811 		break;
2812 	case IB_CM_REJ_RECEIVED:
2813 		srpt_cm_rej_recv(cm_id);
2814 		break;
2815 	case IB_CM_RTU_RECEIVED:
2816 	case IB_CM_USER_ESTABLISHED:
2817 		srpt_cm_rtu_recv(cm_id);
2818 		break;
2819 	case IB_CM_DREQ_RECEIVED:
2820 		srpt_cm_dreq_recv(cm_id);
2821 		break;
2822 	case IB_CM_DREP_RECEIVED:
2823 		srpt_cm_drep_recv(cm_id);
2824 		break;
2825 	case IB_CM_TIMEWAIT_EXIT:
2826 		srpt_cm_timewait_exit(cm_id);
2827 		break;
2828 	case IB_CM_REP_ERROR:
2829 		srpt_cm_rep_error(cm_id);
2830 		break;
2831 	case IB_CM_DREQ_ERROR:
2832 		printk(KERN_INFO "Received IB DREQ ERROR event.\n");
2833 		break;
2834 	case IB_CM_MRA_RECEIVED:
2835 		printk(KERN_INFO "Received IB MRA event\n");
2836 		break;
2837 	default:
2838 		printk(KERN_ERR "received unrecognized IB CM event %d\n",
2839 		       event->event);
2840 		break;
2841 	}
2842 
2843 	return ret;
2844 }
2845 
2846 /**
2847  * srpt_perform_rdmas() - Perform IB RDMA.
2848  *
2849  * Returns zero upon success or a negative number upon failure.
2850  */
2851 static int srpt_perform_rdmas(struct srpt_rdma_ch *ch,
2852 			      struct srpt_send_ioctx *ioctx)
2853 {
2854 	struct ib_send_wr wr;
2855 	struct ib_send_wr *bad_wr;
2856 	struct rdma_iu *riu;
2857 	int i;
2858 	int ret;
2859 	int sq_wr_avail;
2860 	enum dma_data_direction dir;
2861 	const int n_rdma = ioctx->n_rdma;
2862 
2863 	dir = ioctx->cmd.data_direction;
2864 	if (dir == DMA_TO_DEVICE) {
2865 		/* write */
2866 		ret = -ENOMEM;
2867 		sq_wr_avail = atomic_sub_return(n_rdma, &ch->sq_wr_avail);
2868 		if (sq_wr_avail < 0) {
2869 			printk(KERN_WARNING "IB send queue full (needed %d)\n",
2870 			       n_rdma);
2871 			goto out;
2872 		}
2873 	}
2874 
2875 	ioctx->rdma_aborted = false;
2876 	ret = 0;
2877 	riu = ioctx->rdma_ius;
2878 	memset(&wr, 0, sizeof wr);
2879 
2880 	for (i = 0; i < n_rdma; ++i, ++riu) {
2881 		if (dir == DMA_FROM_DEVICE) {
2882 			wr.opcode = IB_WR_RDMA_WRITE;
2883 			wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2884 						SRPT_RDMA_WRITE_LAST :
2885 						SRPT_RDMA_MID,
2886 						ioctx->ioctx.index);
2887 		} else {
2888 			wr.opcode = IB_WR_RDMA_READ;
2889 			wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2890 						SRPT_RDMA_READ_LAST :
2891 						SRPT_RDMA_MID,
2892 						ioctx->ioctx.index);
2893 		}
2894 		wr.next = NULL;
2895 		wr.wr.rdma.remote_addr = riu->raddr;
2896 		wr.wr.rdma.rkey = riu->rkey;
2897 		wr.num_sge = riu->sge_cnt;
2898 		wr.sg_list = riu->sge;
2899 
2900 		/* only get completion event for the last rdma write */
2901 		if (i == (n_rdma - 1) && dir == DMA_TO_DEVICE)
2902 			wr.send_flags = IB_SEND_SIGNALED;
2903 
2904 		ret = ib_post_send(ch->qp, &wr, &bad_wr);
2905 		if (ret)
2906 			break;
2907 	}
2908 
2909 	if (ret)
2910 		printk(KERN_ERR "%s[%d]: ib_post_send() returned %d for %d/%d",
2911 				 __func__, __LINE__, ret, i, n_rdma);
2912 	if (ret && i > 0) {
2913 		wr.num_sge = 0;
2914 		wr.wr_id = encode_wr_id(SRPT_RDMA_ABORT, ioctx->ioctx.index);
2915 		wr.send_flags = IB_SEND_SIGNALED;
2916 		while (ch->state == CH_LIVE &&
2917 			ib_post_send(ch->qp, &wr, &bad_wr) != 0) {
2918 			printk(KERN_INFO "Trying to abort failed RDMA transfer [%d]",
2919 				ioctx->ioctx.index);
2920 			msleep(1000);
2921 		}
2922 		while (ch->state != CH_RELEASING && !ioctx->rdma_aborted) {
2923 			printk(KERN_INFO "Waiting until RDMA abort finished [%d]",
2924 				ioctx->ioctx.index);
2925 			msleep(1000);
2926 		}
2927 	}
2928 out:
2929 	if (unlikely(dir == DMA_TO_DEVICE && ret < 0))
2930 		atomic_add(n_rdma, &ch->sq_wr_avail);
2931 	return ret;
2932 }
2933 
2934 /**
2935  * srpt_xfer_data() - Start data transfer from initiator to target.
2936  */
2937 static int srpt_xfer_data(struct srpt_rdma_ch *ch,
2938 			  struct srpt_send_ioctx *ioctx)
2939 {
2940 	int ret;
2941 
2942 	ret = srpt_map_sg_to_ib_sge(ch, ioctx);
2943 	if (ret) {
2944 		printk(KERN_ERR "%s[%d] ret=%d\n", __func__, __LINE__, ret);
2945 		goto out;
2946 	}
2947 
2948 	ret = srpt_perform_rdmas(ch, ioctx);
2949 	if (ret) {
2950 		if (ret == -EAGAIN || ret == -ENOMEM)
2951 			printk(KERN_INFO "%s[%d] queue full -- ret=%d\n",
2952 				   __func__, __LINE__, ret);
2953 		else
2954 			printk(KERN_ERR "%s[%d] fatal error -- ret=%d\n",
2955 			       __func__, __LINE__, ret);
2956 		goto out_unmap;
2957 	}
2958 
2959 out:
2960 	return ret;
2961 out_unmap:
2962 	srpt_unmap_sg_to_ib_sge(ch, ioctx);
2963 	goto out;
2964 }
2965 
2966 static int srpt_write_pending_status(struct se_cmd *se_cmd)
2967 {
2968 	struct srpt_send_ioctx *ioctx;
2969 
2970 	ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2971 	return srpt_get_cmd_state(ioctx) == SRPT_STATE_NEED_DATA;
2972 }
2973 
2974 /*
2975  * srpt_write_pending() - Start data transfer from initiator to target (write).
2976  */
2977 static int srpt_write_pending(struct se_cmd *se_cmd)
2978 {
2979 	struct srpt_rdma_ch *ch;
2980 	struct srpt_send_ioctx *ioctx;
2981 	enum srpt_command_state new_state;
2982 	enum rdma_ch_state ch_state;
2983 	int ret;
2984 
2985 	ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2986 
2987 	new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA);
2988 	WARN_ON(new_state == SRPT_STATE_DONE);
2989 
2990 	ch = ioctx->ch;
2991 	BUG_ON(!ch);
2992 
2993 	ch_state = srpt_get_ch_state(ch);
2994 	switch (ch_state) {
2995 	case CH_CONNECTING:
2996 		WARN(true, "unexpected channel state %d\n", ch_state);
2997 		ret = -EINVAL;
2998 		goto out;
2999 	case CH_LIVE:
3000 		break;
3001 	case CH_DISCONNECTING:
3002 	case CH_DRAINING:
3003 	case CH_RELEASING:
3004 		pr_debug("cmd with tag %lld: channel disconnecting\n",
3005 			 ioctx->tag);
3006 		srpt_set_cmd_state(ioctx, SRPT_STATE_DATA_IN);
3007 		ret = -EINVAL;
3008 		goto out;
3009 	}
3010 	ret = srpt_xfer_data(ch, ioctx);
3011 
3012 out:
3013 	return ret;
3014 }
3015 
3016 static u8 tcm_to_srp_tsk_mgmt_status(const int tcm_mgmt_status)
3017 {
3018 	switch (tcm_mgmt_status) {
3019 	case TMR_FUNCTION_COMPLETE:
3020 		return SRP_TSK_MGMT_SUCCESS;
3021 	case TMR_FUNCTION_REJECTED:
3022 		return SRP_TSK_MGMT_FUNC_NOT_SUPP;
3023 	}
3024 	return SRP_TSK_MGMT_FAILED;
3025 }
3026 
3027 /**
3028  * srpt_queue_response() - Transmits the response to a SCSI command.
3029  *
3030  * Callback function called by the TCM core. Must not block since it can be
3031  * invoked on the context of the IB completion handler.
3032  */
3033 static int srpt_queue_response(struct se_cmd *cmd)
3034 {
3035 	struct srpt_rdma_ch *ch;
3036 	struct srpt_send_ioctx *ioctx;
3037 	enum srpt_command_state state;
3038 	unsigned long flags;
3039 	int ret;
3040 	enum dma_data_direction dir;
3041 	int resp_len;
3042 	u8 srp_tm_status;
3043 
3044 	ret = 0;
3045 
3046 	ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3047 	ch = ioctx->ch;
3048 	BUG_ON(!ch);
3049 
3050 	spin_lock_irqsave(&ioctx->spinlock, flags);
3051 	state = ioctx->state;
3052 	switch (state) {
3053 	case SRPT_STATE_NEW:
3054 	case SRPT_STATE_DATA_IN:
3055 		ioctx->state = SRPT_STATE_CMD_RSP_SENT;
3056 		break;
3057 	case SRPT_STATE_MGMT:
3058 		ioctx->state = SRPT_STATE_MGMT_RSP_SENT;
3059 		break;
3060 	default:
3061 		WARN(true, "ch %p; cmd %d: unexpected command state %d\n",
3062 			ch, ioctx->ioctx.index, ioctx->state);
3063 		break;
3064 	}
3065 	spin_unlock_irqrestore(&ioctx->spinlock, flags);
3066 
3067 	if (unlikely(transport_check_aborted_status(&ioctx->cmd, false)
3068 		     || WARN_ON_ONCE(state == SRPT_STATE_CMD_RSP_SENT))) {
3069 		atomic_inc(&ch->req_lim_delta);
3070 		srpt_abort_cmd(ioctx);
3071 		goto out;
3072 	}
3073 
3074 	dir = ioctx->cmd.data_direction;
3075 
3076 	/* For read commands, transfer the data to the initiator. */
3077 	if (dir == DMA_FROM_DEVICE && ioctx->cmd.data_length &&
3078 	    !ioctx->queue_status_only) {
3079 		ret = srpt_xfer_data(ch, ioctx);
3080 		if (ret) {
3081 			printk(KERN_ERR "xfer_data failed for tag %llu\n",
3082 			       ioctx->tag);
3083 			goto out;
3084 		}
3085 	}
3086 
3087 	if (state != SRPT_STATE_MGMT)
3088 		resp_len = srpt_build_cmd_rsp(ch, ioctx, ioctx->tag,
3089 					      cmd->scsi_status);
3090 	else {
3091 		srp_tm_status
3092 			= tcm_to_srp_tsk_mgmt_status(cmd->se_tmr_req->response);
3093 		resp_len = srpt_build_tskmgmt_rsp(ch, ioctx, srp_tm_status,
3094 						 ioctx->tag);
3095 	}
3096 	ret = srpt_post_send(ch, ioctx, resp_len);
3097 	if (ret) {
3098 		printk(KERN_ERR "sending cmd response failed for tag %llu\n",
3099 		       ioctx->tag);
3100 		srpt_unmap_sg_to_ib_sge(ch, ioctx);
3101 		srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
3102 		kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
3103 	}
3104 
3105 out:
3106 	return ret;
3107 }
3108 
3109 static int srpt_queue_status(struct se_cmd *cmd)
3110 {
3111 	struct srpt_send_ioctx *ioctx;
3112 
3113 	ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3114 	BUG_ON(ioctx->sense_data != cmd->sense_buffer);
3115 	if (cmd->se_cmd_flags &
3116 	    (SCF_TRANSPORT_TASK_SENSE | SCF_EMULATED_TASK_SENSE))
3117 		WARN_ON(cmd->scsi_status != SAM_STAT_CHECK_CONDITION);
3118 	ioctx->queue_status_only = true;
3119 	return srpt_queue_response(cmd);
3120 }
3121 
3122 static void srpt_refresh_port_work(struct work_struct *work)
3123 {
3124 	struct srpt_port *sport = container_of(work, struct srpt_port, work);
3125 
3126 	srpt_refresh_port(sport);
3127 }
3128 
3129 static int srpt_ch_list_empty(struct srpt_device *sdev)
3130 {
3131 	int res;
3132 
3133 	spin_lock_irq(&sdev->spinlock);
3134 	res = list_empty(&sdev->rch_list);
3135 	spin_unlock_irq(&sdev->spinlock);
3136 
3137 	return res;
3138 }
3139 
3140 /**
3141  * srpt_release_sdev() - Free the channel resources associated with a target.
3142  */
3143 static int srpt_release_sdev(struct srpt_device *sdev)
3144 {
3145 	struct srpt_rdma_ch *ch, *tmp_ch;
3146 	int res;
3147 
3148 	WARN_ON_ONCE(irqs_disabled());
3149 
3150 	BUG_ON(!sdev);
3151 
3152 	spin_lock_irq(&sdev->spinlock);
3153 	list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list)
3154 		__srpt_close_ch(ch);
3155 	spin_unlock_irq(&sdev->spinlock);
3156 
3157 	res = wait_event_interruptible(sdev->ch_releaseQ,
3158 				       srpt_ch_list_empty(sdev));
3159 	if (res)
3160 		printk(KERN_ERR "%s: interrupted.\n", __func__);
3161 
3162 	return 0;
3163 }
3164 
3165 static struct srpt_port *__srpt_lookup_port(const char *name)
3166 {
3167 	struct ib_device *dev;
3168 	struct srpt_device *sdev;
3169 	struct srpt_port *sport;
3170 	int i;
3171 
3172 	list_for_each_entry(sdev, &srpt_dev_list, list) {
3173 		dev = sdev->device;
3174 		if (!dev)
3175 			continue;
3176 
3177 		for (i = 0; i < dev->phys_port_cnt; i++) {
3178 			sport = &sdev->port[i];
3179 
3180 			if (!strcmp(sport->port_guid, name))
3181 				return sport;
3182 		}
3183 	}
3184 
3185 	return NULL;
3186 }
3187 
3188 static struct srpt_port *srpt_lookup_port(const char *name)
3189 {
3190 	struct srpt_port *sport;
3191 
3192 	spin_lock(&srpt_dev_lock);
3193 	sport = __srpt_lookup_port(name);
3194 	spin_unlock(&srpt_dev_lock);
3195 
3196 	return sport;
3197 }
3198 
3199 /**
3200  * srpt_add_one() - Infiniband device addition callback function.
3201  */
3202 static void srpt_add_one(struct ib_device *device)
3203 {
3204 	struct srpt_device *sdev;
3205 	struct srpt_port *sport;
3206 	struct ib_srq_init_attr srq_attr;
3207 	int i;
3208 
3209 	pr_debug("device = %p, device->dma_ops = %p\n", device,
3210 		 device->dma_ops);
3211 
3212 	sdev = kzalloc(sizeof *sdev, GFP_KERNEL);
3213 	if (!sdev)
3214 		goto err;
3215 
3216 	sdev->device = device;
3217 	INIT_LIST_HEAD(&sdev->rch_list);
3218 	init_waitqueue_head(&sdev->ch_releaseQ);
3219 	spin_lock_init(&sdev->spinlock);
3220 
3221 	if (ib_query_device(device, &sdev->dev_attr))
3222 		goto free_dev;
3223 
3224 	sdev->pd = ib_alloc_pd(device);
3225 	if (IS_ERR(sdev->pd))
3226 		goto free_dev;
3227 
3228 	sdev->mr = ib_get_dma_mr(sdev->pd, IB_ACCESS_LOCAL_WRITE);
3229 	if (IS_ERR(sdev->mr))
3230 		goto err_pd;
3231 
3232 	sdev->srq_size = min(srpt_srq_size, sdev->dev_attr.max_srq_wr);
3233 
3234 	srq_attr.event_handler = srpt_srq_event;
3235 	srq_attr.srq_context = (void *)sdev;
3236 	srq_attr.attr.max_wr = sdev->srq_size;
3237 	srq_attr.attr.max_sge = 1;
3238 	srq_attr.attr.srq_limit = 0;
3239 	srq_attr.srq_type = IB_SRQT_BASIC;
3240 
3241 	sdev->srq = ib_create_srq(sdev->pd, &srq_attr);
3242 	if (IS_ERR(sdev->srq))
3243 		goto err_mr;
3244 
3245 	pr_debug("%s: create SRQ #wr= %d max_allow=%d dev= %s\n",
3246 		 __func__, sdev->srq_size, sdev->dev_attr.max_srq_wr,
3247 		 device->name);
3248 
3249 	if (!srpt_service_guid)
3250 		srpt_service_guid = be64_to_cpu(device->node_guid);
3251 
3252 	sdev->cm_id = ib_create_cm_id(device, srpt_cm_handler, sdev);
3253 	if (IS_ERR(sdev->cm_id))
3254 		goto err_srq;
3255 
3256 	/* print out target login information */
3257 	pr_debug("Target login info: id_ext=%016llx,ioc_guid=%016llx,"
3258 		 "pkey=ffff,service_id=%016llx\n", srpt_service_guid,
3259 		 srpt_service_guid, srpt_service_guid);
3260 
3261 	/*
3262 	 * We do not have a consistent service_id (ie. also id_ext of target_id)
3263 	 * to identify this target. We currently use the guid of the first HCA
3264 	 * in the system as service_id; therefore, the target_id will change
3265 	 * if this HCA is gone bad and replaced by different HCA
3266 	 */
3267 	if (ib_cm_listen(sdev->cm_id, cpu_to_be64(srpt_service_guid), 0, NULL))
3268 		goto err_cm;
3269 
3270 	INIT_IB_EVENT_HANDLER(&sdev->event_handler, sdev->device,
3271 			      srpt_event_handler);
3272 	if (ib_register_event_handler(&sdev->event_handler))
3273 		goto err_cm;
3274 
3275 	sdev->ioctx_ring = (struct srpt_recv_ioctx **)
3276 		srpt_alloc_ioctx_ring(sdev, sdev->srq_size,
3277 				      sizeof(*sdev->ioctx_ring[0]),
3278 				      srp_max_req_size, DMA_FROM_DEVICE);
3279 	if (!sdev->ioctx_ring)
3280 		goto err_event;
3281 
3282 	for (i = 0; i < sdev->srq_size; ++i)
3283 		srpt_post_recv(sdev, sdev->ioctx_ring[i]);
3284 
3285 	WARN_ON(sdev->device->phys_port_cnt > ARRAY_SIZE(sdev->port));
3286 
3287 	for (i = 1; i <= sdev->device->phys_port_cnt; i++) {
3288 		sport = &sdev->port[i - 1];
3289 		sport->sdev = sdev;
3290 		sport->port = i;
3291 		sport->port_attrib.srp_max_rdma_size = DEFAULT_MAX_RDMA_SIZE;
3292 		sport->port_attrib.srp_max_rsp_size = DEFAULT_MAX_RSP_SIZE;
3293 		sport->port_attrib.srp_sq_size = DEF_SRPT_SQ_SIZE;
3294 		INIT_WORK(&sport->work, srpt_refresh_port_work);
3295 		INIT_LIST_HEAD(&sport->port_acl_list);
3296 		spin_lock_init(&sport->port_acl_lock);
3297 
3298 		if (srpt_refresh_port(sport)) {
3299 			printk(KERN_ERR "MAD registration failed for %s-%d.\n",
3300 			       srpt_sdev_name(sdev), i);
3301 			goto err_ring;
3302 		}
3303 		snprintf(sport->port_guid, sizeof(sport->port_guid),
3304 			"0x%016llx%016llx",
3305 			be64_to_cpu(sport->gid.global.subnet_prefix),
3306 			be64_to_cpu(sport->gid.global.interface_id));
3307 	}
3308 
3309 	spin_lock(&srpt_dev_lock);
3310 	list_add_tail(&sdev->list, &srpt_dev_list);
3311 	spin_unlock(&srpt_dev_lock);
3312 
3313 out:
3314 	ib_set_client_data(device, &srpt_client, sdev);
3315 	pr_debug("added %s.\n", device->name);
3316 	return;
3317 
3318 err_ring:
3319 	srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
3320 			     sdev->srq_size, srp_max_req_size,
3321 			     DMA_FROM_DEVICE);
3322 err_event:
3323 	ib_unregister_event_handler(&sdev->event_handler);
3324 err_cm:
3325 	ib_destroy_cm_id(sdev->cm_id);
3326 err_srq:
3327 	ib_destroy_srq(sdev->srq);
3328 err_mr:
3329 	ib_dereg_mr(sdev->mr);
3330 err_pd:
3331 	ib_dealloc_pd(sdev->pd);
3332 free_dev:
3333 	kfree(sdev);
3334 err:
3335 	sdev = NULL;
3336 	printk(KERN_INFO "%s(%s) failed.\n", __func__, device->name);
3337 	goto out;
3338 }
3339 
3340 /**
3341  * srpt_remove_one() - InfiniBand device removal callback function.
3342  */
3343 static void srpt_remove_one(struct ib_device *device)
3344 {
3345 	struct srpt_device *sdev;
3346 	int i;
3347 
3348 	sdev = ib_get_client_data(device, &srpt_client);
3349 	if (!sdev) {
3350 		printk(KERN_INFO "%s(%s): nothing to do.\n", __func__,
3351 		       device->name);
3352 		return;
3353 	}
3354 
3355 	srpt_unregister_mad_agent(sdev);
3356 
3357 	ib_unregister_event_handler(&sdev->event_handler);
3358 
3359 	/* Cancel any work queued by the just unregistered IB event handler. */
3360 	for (i = 0; i < sdev->device->phys_port_cnt; i++)
3361 		cancel_work_sync(&sdev->port[i].work);
3362 
3363 	ib_destroy_cm_id(sdev->cm_id);
3364 
3365 	/*
3366 	 * Unregistering a target must happen after destroying sdev->cm_id
3367 	 * such that no new SRP_LOGIN_REQ information units can arrive while
3368 	 * destroying the target.
3369 	 */
3370 	spin_lock(&srpt_dev_lock);
3371 	list_del(&sdev->list);
3372 	spin_unlock(&srpt_dev_lock);
3373 	srpt_release_sdev(sdev);
3374 
3375 	ib_destroy_srq(sdev->srq);
3376 	ib_dereg_mr(sdev->mr);
3377 	ib_dealloc_pd(sdev->pd);
3378 
3379 	srpt_free_ioctx_ring((struct srpt_ioctx **)sdev->ioctx_ring, sdev,
3380 			     sdev->srq_size, srp_max_req_size, DMA_FROM_DEVICE);
3381 	sdev->ioctx_ring = NULL;
3382 	kfree(sdev);
3383 }
3384 
3385 static struct ib_client srpt_client = {
3386 	.name = DRV_NAME,
3387 	.add = srpt_add_one,
3388 	.remove = srpt_remove_one
3389 };
3390 
3391 static int srpt_check_true(struct se_portal_group *se_tpg)
3392 {
3393 	return 1;
3394 }
3395 
3396 static int srpt_check_false(struct se_portal_group *se_tpg)
3397 {
3398 	return 0;
3399 }
3400 
3401 static char *srpt_get_fabric_name(void)
3402 {
3403 	return "srpt";
3404 }
3405 
3406 static u8 srpt_get_fabric_proto_ident(struct se_portal_group *se_tpg)
3407 {
3408 	return SCSI_TRANSPORTID_PROTOCOLID_SRP;
3409 }
3410 
3411 static char *srpt_get_fabric_wwn(struct se_portal_group *tpg)
3412 {
3413 	struct srpt_port *sport = container_of(tpg, struct srpt_port, port_tpg_1);
3414 
3415 	return sport->port_guid;
3416 }
3417 
3418 static u16 srpt_get_tag(struct se_portal_group *tpg)
3419 {
3420 	return 1;
3421 }
3422 
3423 static u32 srpt_get_default_depth(struct se_portal_group *se_tpg)
3424 {
3425 	return 1;
3426 }
3427 
3428 static u32 srpt_get_pr_transport_id(struct se_portal_group *se_tpg,
3429 				    struct se_node_acl *se_nacl,
3430 				    struct t10_pr_registration *pr_reg,
3431 				    int *format_code, unsigned char *buf)
3432 {
3433 	struct srpt_node_acl *nacl;
3434 	struct spc_rdma_transport_id *tr_id;
3435 
3436 	nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3437 	tr_id = (void *)buf;
3438 	tr_id->protocol_identifier = SCSI_TRANSPORTID_PROTOCOLID_SRP;
3439 	memcpy(tr_id->i_port_id, nacl->i_port_id, sizeof(tr_id->i_port_id));
3440 	return sizeof(*tr_id);
3441 }
3442 
3443 static u32 srpt_get_pr_transport_id_len(struct se_portal_group *se_tpg,
3444 					struct se_node_acl *se_nacl,
3445 					struct t10_pr_registration *pr_reg,
3446 					int *format_code)
3447 {
3448 	*format_code = 0;
3449 	return sizeof(struct spc_rdma_transport_id);
3450 }
3451 
3452 static char *srpt_parse_pr_out_transport_id(struct se_portal_group *se_tpg,
3453 					    const char *buf, u32 *out_tid_len,
3454 					    char **port_nexus_ptr)
3455 {
3456 	struct spc_rdma_transport_id *tr_id;
3457 
3458 	*port_nexus_ptr = NULL;
3459 	*out_tid_len = sizeof(struct spc_rdma_transport_id);
3460 	tr_id = (void *)buf;
3461 	return (char *)tr_id->i_port_id;
3462 }
3463 
3464 static struct se_node_acl *srpt_alloc_fabric_acl(struct se_portal_group *se_tpg)
3465 {
3466 	struct srpt_node_acl *nacl;
3467 
3468 	nacl = kzalloc(sizeof(struct srpt_node_acl), GFP_KERNEL);
3469 	if (!nacl) {
3470 		printk(KERN_ERR "Unable to allocate struct srpt_node_acl\n");
3471 		return NULL;
3472 	}
3473 
3474 	return &nacl->nacl;
3475 }
3476 
3477 static void srpt_release_fabric_acl(struct se_portal_group *se_tpg,
3478 				    struct se_node_acl *se_nacl)
3479 {
3480 	struct srpt_node_acl *nacl;
3481 
3482 	nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3483 	kfree(nacl);
3484 }
3485 
3486 static u32 srpt_tpg_get_inst_index(struct se_portal_group *se_tpg)
3487 {
3488 	return 1;
3489 }
3490 
3491 static void srpt_release_cmd(struct se_cmd *se_cmd)
3492 {
3493 }
3494 
3495 /**
3496  * srpt_shutdown_session() - Whether or not a session may be shut down.
3497  */
3498 static int srpt_shutdown_session(struct se_session *se_sess)
3499 {
3500 	return true;
3501 }
3502 
3503 /**
3504  * srpt_close_session() - Forcibly close a session.
3505  *
3506  * Callback function invoked by the TCM core to clean up sessions associated
3507  * with a node ACL when the user invokes
3508  * rmdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3509  */
3510 static void srpt_close_session(struct se_session *se_sess)
3511 {
3512 	DECLARE_COMPLETION_ONSTACK(release_done);
3513 	struct srpt_rdma_ch *ch;
3514 	struct srpt_device *sdev;
3515 	int res;
3516 
3517 	ch = se_sess->fabric_sess_ptr;
3518 	WARN_ON(ch->sess != se_sess);
3519 
3520 	pr_debug("ch %p state %d\n", ch, srpt_get_ch_state(ch));
3521 
3522 	sdev = ch->sport->sdev;
3523 	spin_lock_irq(&sdev->spinlock);
3524 	BUG_ON(ch->release_done);
3525 	ch->release_done = &release_done;
3526 	__srpt_close_ch(ch);
3527 	spin_unlock_irq(&sdev->spinlock);
3528 
3529 	res = wait_for_completion_timeout(&release_done, 60 * HZ);
3530 	WARN_ON(res <= 0);
3531 }
3532 
3533 /**
3534  * srpt_sess_get_index() - Return the value of scsiAttIntrPortIndex (SCSI-MIB).
3535  *
3536  * A quote from RFC 4455 (SCSI-MIB) about this MIB object:
3537  * This object represents an arbitrary integer used to uniquely identify a
3538  * particular attached remote initiator port to a particular SCSI target port
3539  * within a particular SCSI target device within a particular SCSI instance.
3540  */
3541 static u32 srpt_sess_get_index(struct se_session *se_sess)
3542 {
3543 	return 0;
3544 }
3545 
3546 static void srpt_set_default_node_attrs(struct se_node_acl *nacl)
3547 {
3548 }
3549 
3550 static u32 srpt_get_task_tag(struct se_cmd *se_cmd)
3551 {
3552 	struct srpt_send_ioctx *ioctx;
3553 
3554 	ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
3555 	return ioctx->tag;
3556 }
3557 
3558 /* Note: only used from inside debug printk's by the TCM core. */
3559 static int srpt_get_tcm_cmd_state(struct se_cmd *se_cmd)
3560 {
3561 	struct srpt_send_ioctx *ioctx;
3562 
3563 	ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
3564 	return srpt_get_cmd_state(ioctx);
3565 }
3566 
3567 static u16 srpt_set_fabric_sense_len(struct se_cmd *cmd, u32 sense_length)
3568 {
3569 	return 0;
3570 }
3571 
3572 static u16 srpt_get_fabric_sense_len(void)
3573 {
3574 	return 0;
3575 }
3576 
3577 /**
3578  * srpt_parse_i_port_id() - Parse an initiator port ID.
3579  * @name: ASCII representation of a 128-bit initiator port ID.
3580  * @i_port_id: Binary 128-bit port ID.
3581  */
3582 static int srpt_parse_i_port_id(u8 i_port_id[16], const char *name)
3583 {
3584 	const char *p;
3585 	unsigned len, count, leading_zero_bytes;
3586 	int ret, rc;
3587 
3588 	p = name;
3589 	if (strnicmp(p, "0x", 2) == 0)
3590 		p += 2;
3591 	ret = -EINVAL;
3592 	len = strlen(p);
3593 	if (len % 2)
3594 		goto out;
3595 	count = min(len / 2, 16U);
3596 	leading_zero_bytes = 16 - count;
3597 	memset(i_port_id, 0, leading_zero_bytes);
3598 	rc = hex2bin(i_port_id + leading_zero_bytes, p, count);
3599 	if (rc < 0)
3600 		pr_debug("hex2bin failed for srpt_parse_i_port_id: %d\n", rc);
3601 	ret = 0;
3602 out:
3603 	return ret;
3604 }
3605 
3606 /*
3607  * configfs callback function invoked for
3608  * mkdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3609  */
3610 static struct se_node_acl *srpt_make_nodeacl(struct se_portal_group *tpg,
3611 					     struct config_group *group,
3612 					     const char *name)
3613 {
3614 	struct srpt_port *sport = container_of(tpg, struct srpt_port, port_tpg_1);
3615 	struct se_node_acl *se_nacl, *se_nacl_new;
3616 	struct srpt_node_acl *nacl;
3617 	int ret = 0;
3618 	u32 nexus_depth = 1;
3619 	u8 i_port_id[16];
3620 
3621 	if (srpt_parse_i_port_id(i_port_id, name) < 0) {
3622 		printk(KERN_ERR "invalid initiator port ID %s\n", name);
3623 		ret = -EINVAL;
3624 		goto err;
3625 	}
3626 
3627 	se_nacl_new = srpt_alloc_fabric_acl(tpg);
3628 	if (!se_nacl_new) {
3629 		ret = -ENOMEM;
3630 		goto err;
3631 	}
3632 	/*
3633 	 * nacl_new may be released by core_tpg_add_initiator_node_acl()
3634 	 * when converting a node ACL from demo mode to explict
3635 	 */
3636 	se_nacl = core_tpg_add_initiator_node_acl(tpg, se_nacl_new, name,
3637 						  nexus_depth);
3638 	if (IS_ERR(se_nacl)) {
3639 		ret = PTR_ERR(se_nacl);
3640 		goto err;
3641 	}
3642 	/* Locate our struct srpt_node_acl and set sdev and i_port_id. */
3643 	nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3644 	memcpy(&nacl->i_port_id[0], &i_port_id[0], 16);
3645 	nacl->sport = sport;
3646 
3647 	spin_lock_irq(&sport->port_acl_lock);
3648 	list_add_tail(&nacl->list, &sport->port_acl_list);
3649 	spin_unlock_irq(&sport->port_acl_lock);
3650 
3651 	return se_nacl;
3652 err:
3653 	return ERR_PTR(ret);
3654 }
3655 
3656 /*
3657  * configfs callback function invoked for
3658  * rmdir /sys/kernel/config/target/$driver/$port/$tpg/acls/$i_port_id
3659  */
3660 static void srpt_drop_nodeacl(struct se_node_acl *se_nacl)
3661 {
3662 	struct srpt_node_acl *nacl;
3663 	struct srpt_device *sdev;
3664 	struct srpt_port *sport;
3665 
3666 	nacl = container_of(se_nacl, struct srpt_node_acl, nacl);
3667 	sport = nacl->sport;
3668 	sdev = sport->sdev;
3669 	spin_lock_irq(&sport->port_acl_lock);
3670 	list_del(&nacl->list);
3671 	spin_unlock_irq(&sport->port_acl_lock);
3672 	core_tpg_del_initiator_node_acl(&sport->port_tpg_1, se_nacl, 1);
3673 	srpt_release_fabric_acl(NULL, se_nacl);
3674 }
3675 
3676 static ssize_t srpt_tpg_attrib_show_srp_max_rdma_size(
3677 	struct se_portal_group *se_tpg,
3678 	char *page)
3679 {
3680 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3681 
3682 	return sprintf(page, "%u\n", sport->port_attrib.srp_max_rdma_size);
3683 }
3684 
3685 static ssize_t srpt_tpg_attrib_store_srp_max_rdma_size(
3686 	struct se_portal_group *se_tpg,
3687 	const char *page,
3688 	size_t count)
3689 {
3690 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3691 	unsigned long val;
3692 	int ret;
3693 
3694 	ret = strict_strtoul(page, 0, &val);
3695 	if (ret < 0) {
3696 		pr_err("strict_strtoul() failed with ret: %d\n", ret);
3697 		return -EINVAL;
3698 	}
3699 	if (val > MAX_SRPT_RDMA_SIZE) {
3700 		pr_err("val: %lu exceeds MAX_SRPT_RDMA_SIZE: %d\n", val,
3701 			MAX_SRPT_RDMA_SIZE);
3702 		return -EINVAL;
3703 	}
3704 	if (val < DEFAULT_MAX_RDMA_SIZE) {
3705 		pr_err("val: %lu smaller than DEFAULT_MAX_RDMA_SIZE: %d\n",
3706 			val, DEFAULT_MAX_RDMA_SIZE);
3707 		return -EINVAL;
3708 	}
3709 	sport->port_attrib.srp_max_rdma_size = val;
3710 
3711 	return count;
3712 }
3713 
3714 TF_TPG_ATTRIB_ATTR(srpt, srp_max_rdma_size, S_IRUGO | S_IWUSR);
3715 
3716 static ssize_t srpt_tpg_attrib_show_srp_max_rsp_size(
3717 	struct se_portal_group *se_tpg,
3718 	char *page)
3719 {
3720 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3721 
3722 	return sprintf(page, "%u\n", sport->port_attrib.srp_max_rsp_size);
3723 }
3724 
3725 static ssize_t srpt_tpg_attrib_store_srp_max_rsp_size(
3726 	struct se_portal_group *se_tpg,
3727 	const char *page,
3728 	size_t count)
3729 {
3730 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3731 	unsigned long val;
3732 	int ret;
3733 
3734 	ret = strict_strtoul(page, 0, &val);
3735 	if (ret < 0) {
3736 		pr_err("strict_strtoul() failed with ret: %d\n", ret);
3737 		return -EINVAL;
3738 	}
3739 	if (val > MAX_SRPT_RSP_SIZE) {
3740 		pr_err("val: %lu exceeds MAX_SRPT_RSP_SIZE: %d\n", val,
3741 			MAX_SRPT_RSP_SIZE);
3742 		return -EINVAL;
3743 	}
3744 	if (val < MIN_MAX_RSP_SIZE) {
3745 		pr_err("val: %lu smaller than MIN_MAX_RSP_SIZE: %d\n", val,
3746 			MIN_MAX_RSP_SIZE);
3747 		return -EINVAL;
3748 	}
3749 	sport->port_attrib.srp_max_rsp_size = val;
3750 
3751 	return count;
3752 }
3753 
3754 TF_TPG_ATTRIB_ATTR(srpt, srp_max_rsp_size, S_IRUGO | S_IWUSR);
3755 
3756 static ssize_t srpt_tpg_attrib_show_srp_sq_size(
3757 	struct se_portal_group *se_tpg,
3758 	char *page)
3759 {
3760 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3761 
3762 	return sprintf(page, "%u\n", sport->port_attrib.srp_sq_size);
3763 }
3764 
3765 static ssize_t srpt_tpg_attrib_store_srp_sq_size(
3766 	struct se_portal_group *se_tpg,
3767 	const char *page,
3768 	size_t count)
3769 {
3770 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3771 	unsigned long val;
3772 	int ret;
3773 
3774 	ret = strict_strtoul(page, 0, &val);
3775 	if (ret < 0) {
3776 		pr_err("strict_strtoul() failed with ret: %d\n", ret);
3777 		return -EINVAL;
3778 	}
3779 	if (val > MAX_SRPT_SRQ_SIZE) {
3780 		pr_err("val: %lu exceeds MAX_SRPT_SRQ_SIZE: %d\n", val,
3781 			MAX_SRPT_SRQ_SIZE);
3782 		return -EINVAL;
3783 	}
3784 	if (val < MIN_SRPT_SRQ_SIZE) {
3785 		pr_err("val: %lu smaller than MIN_SRPT_SRQ_SIZE: %d\n", val,
3786 			MIN_SRPT_SRQ_SIZE);
3787 		return -EINVAL;
3788 	}
3789 	sport->port_attrib.srp_sq_size = val;
3790 
3791 	return count;
3792 }
3793 
3794 TF_TPG_ATTRIB_ATTR(srpt, srp_sq_size, S_IRUGO | S_IWUSR);
3795 
3796 static struct configfs_attribute *srpt_tpg_attrib_attrs[] = {
3797 	&srpt_tpg_attrib_srp_max_rdma_size.attr,
3798 	&srpt_tpg_attrib_srp_max_rsp_size.attr,
3799 	&srpt_tpg_attrib_srp_sq_size.attr,
3800 	NULL,
3801 };
3802 
3803 static ssize_t srpt_tpg_show_enable(
3804 	struct se_portal_group *se_tpg,
3805 	char *page)
3806 {
3807 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3808 
3809 	return snprintf(page, PAGE_SIZE, "%d\n", (sport->enabled) ? 1: 0);
3810 }
3811 
3812 static ssize_t srpt_tpg_store_enable(
3813 	struct se_portal_group *se_tpg,
3814 	const char *page,
3815 	size_t count)
3816 {
3817 	struct srpt_port *sport = container_of(se_tpg, struct srpt_port, port_tpg_1);
3818 	unsigned long tmp;
3819         int ret;
3820 
3821 	ret = strict_strtoul(page, 0, &tmp);
3822 	if (ret < 0) {
3823 		printk(KERN_ERR "Unable to extract srpt_tpg_store_enable\n");
3824 		return -EINVAL;
3825 	}
3826 
3827 	if ((tmp != 0) && (tmp != 1)) {
3828 		printk(KERN_ERR "Illegal value for srpt_tpg_store_enable: %lu\n", tmp);
3829 		return -EINVAL;
3830 	}
3831 	if (tmp == 1)
3832 		sport->enabled = true;
3833 	else
3834 		sport->enabled = false;
3835 
3836 	return count;
3837 }
3838 
3839 TF_TPG_BASE_ATTR(srpt, enable, S_IRUGO | S_IWUSR);
3840 
3841 static struct configfs_attribute *srpt_tpg_attrs[] = {
3842 	&srpt_tpg_enable.attr,
3843 	NULL,
3844 };
3845 
3846 /**
3847  * configfs callback invoked for
3848  * mkdir /sys/kernel/config/target/$driver/$port/$tpg
3849  */
3850 static struct se_portal_group *srpt_make_tpg(struct se_wwn *wwn,
3851 					     struct config_group *group,
3852 					     const char *name)
3853 {
3854 	struct srpt_port *sport = container_of(wwn, struct srpt_port, port_wwn);
3855 	int res;
3856 
3857 	/* Initialize sport->port_wwn and sport->port_tpg_1 */
3858 	res = core_tpg_register(&srpt_target->tf_ops, &sport->port_wwn,
3859 			&sport->port_tpg_1, sport, TRANSPORT_TPG_TYPE_NORMAL);
3860 	if (res)
3861 		return ERR_PTR(res);
3862 
3863 	return &sport->port_tpg_1;
3864 }
3865 
3866 /**
3867  * configfs callback invoked for
3868  * rmdir /sys/kernel/config/target/$driver/$port/$tpg
3869  */
3870 static void srpt_drop_tpg(struct se_portal_group *tpg)
3871 {
3872 	struct srpt_port *sport = container_of(tpg,
3873 				struct srpt_port, port_tpg_1);
3874 
3875 	sport->enabled = false;
3876 	core_tpg_deregister(&sport->port_tpg_1);
3877 }
3878 
3879 /**
3880  * configfs callback invoked for
3881  * mkdir /sys/kernel/config/target/$driver/$port
3882  */
3883 static struct se_wwn *srpt_make_tport(struct target_fabric_configfs *tf,
3884 				      struct config_group *group,
3885 				      const char *name)
3886 {
3887 	struct srpt_port *sport;
3888 	int ret;
3889 
3890 	sport = srpt_lookup_port(name);
3891 	pr_debug("make_tport(%s)\n", name);
3892 	ret = -EINVAL;
3893 	if (!sport)
3894 		goto err;
3895 
3896 	return &sport->port_wwn;
3897 
3898 err:
3899 	return ERR_PTR(ret);
3900 }
3901 
3902 /**
3903  * configfs callback invoked for
3904  * rmdir /sys/kernel/config/target/$driver/$port
3905  */
3906 static void srpt_drop_tport(struct se_wwn *wwn)
3907 {
3908 	struct srpt_port *sport = container_of(wwn, struct srpt_port, port_wwn);
3909 
3910 	pr_debug("drop_tport(%s\n", config_item_name(&sport->port_wwn.wwn_group.cg_item));
3911 }
3912 
3913 static ssize_t srpt_wwn_show_attr_version(struct target_fabric_configfs *tf,
3914 					      char *buf)
3915 {
3916 	return scnprintf(buf, PAGE_SIZE, "%s\n", DRV_VERSION);
3917 }
3918 
3919 TF_WWN_ATTR_RO(srpt, version);
3920 
3921 static struct configfs_attribute *srpt_wwn_attrs[] = {
3922 	&srpt_wwn_version.attr,
3923 	NULL,
3924 };
3925 
3926 static struct target_core_fabric_ops srpt_template = {
3927 	.get_fabric_name		= srpt_get_fabric_name,
3928 	.get_fabric_proto_ident		= srpt_get_fabric_proto_ident,
3929 	.tpg_get_wwn			= srpt_get_fabric_wwn,
3930 	.tpg_get_tag			= srpt_get_tag,
3931 	.tpg_get_default_depth		= srpt_get_default_depth,
3932 	.tpg_get_pr_transport_id	= srpt_get_pr_transport_id,
3933 	.tpg_get_pr_transport_id_len	= srpt_get_pr_transport_id_len,
3934 	.tpg_parse_pr_out_transport_id	= srpt_parse_pr_out_transport_id,
3935 	.tpg_check_demo_mode		= srpt_check_false,
3936 	.tpg_check_demo_mode_cache	= srpt_check_true,
3937 	.tpg_check_demo_mode_write_protect = srpt_check_true,
3938 	.tpg_check_prod_mode_write_protect = srpt_check_false,
3939 	.tpg_alloc_fabric_acl		= srpt_alloc_fabric_acl,
3940 	.tpg_release_fabric_acl		= srpt_release_fabric_acl,
3941 	.tpg_get_inst_index		= srpt_tpg_get_inst_index,
3942 	.release_cmd			= srpt_release_cmd,
3943 	.check_stop_free		= srpt_check_stop_free,
3944 	.shutdown_session		= srpt_shutdown_session,
3945 	.close_session			= srpt_close_session,
3946 	.sess_get_index			= srpt_sess_get_index,
3947 	.sess_get_initiator_sid		= NULL,
3948 	.write_pending			= srpt_write_pending,
3949 	.write_pending_status		= srpt_write_pending_status,
3950 	.set_default_node_attributes	= srpt_set_default_node_attrs,
3951 	.get_task_tag			= srpt_get_task_tag,
3952 	.get_cmd_state			= srpt_get_tcm_cmd_state,
3953 	.queue_data_in			= srpt_queue_response,
3954 	.queue_status			= srpt_queue_status,
3955 	.queue_tm_rsp			= srpt_queue_response,
3956 	.get_fabric_sense_len		= srpt_get_fabric_sense_len,
3957 	.set_fabric_sense_len		= srpt_set_fabric_sense_len,
3958 	/*
3959 	 * Setup function pointers for generic logic in
3960 	 * target_core_fabric_configfs.c
3961 	 */
3962 	.fabric_make_wwn		= srpt_make_tport,
3963 	.fabric_drop_wwn		= srpt_drop_tport,
3964 	.fabric_make_tpg		= srpt_make_tpg,
3965 	.fabric_drop_tpg		= srpt_drop_tpg,
3966 	.fabric_post_link		= NULL,
3967 	.fabric_pre_unlink		= NULL,
3968 	.fabric_make_np			= NULL,
3969 	.fabric_drop_np			= NULL,
3970 	.fabric_make_nodeacl		= srpt_make_nodeacl,
3971 	.fabric_drop_nodeacl		= srpt_drop_nodeacl,
3972 };
3973 
3974 /**
3975  * srpt_init_module() - Kernel module initialization.
3976  *
3977  * Note: Since ib_register_client() registers callback functions, and since at
3978  * least one of these callback functions (srpt_add_one()) calls target core
3979  * functions, this driver must be registered with the target core before
3980  * ib_register_client() is called.
3981  */
3982 static int __init srpt_init_module(void)
3983 {
3984 	int ret;
3985 
3986 	ret = -EINVAL;
3987 	if (srp_max_req_size < MIN_MAX_REQ_SIZE) {
3988 		printk(KERN_ERR "invalid value %d for kernel module parameter"
3989 		       " srp_max_req_size -- must be at least %d.\n",
3990 		       srp_max_req_size, MIN_MAX_REQ_SIZE);
3991 		goto out;
3992 	}
3993 
3994 	if (srpt_srq_size < MIN_SRPT_SRQ_SIZE
3995 	    || srpt_srq_size > MAX_SRPT_SRQ_SIZE) {
3996 		printk(KERN_ERR "invalid value %d for kernel module parameter"
3997 		       " srpt_srq_size -- must be in the range [%d..%d].\n",
3998 		       srpt_srq_size, MIN_SRPT_SRQ_SIZE, MAX_SRPT_SRQ_SIZE);
3999 		goto out;
4000 	}
4001 
4002 	srpt_target = target_fabric_configfs_init(THIS_MODULE, "srpt");
4003 	if (IS_ERR(srpt_target)) {
4004 		printk(KERN_ERR "couldn't register\n");
4005 		ret = PTR_ERR(srpt_target);
4006 		goto out;
4007 	}
4008 
4009 	srpt_target->tf_ops = srpt_template;
4010 
4011 	/*
4012 	 * Set up default attribute lists.
4013 	 */
4014 	srpt_target->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = srpt_wwn_attrs;
4015 	srpt_target->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = srpt_tpg_attrs;
4016 	srpt_target->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = srpt_tpg_attrib_attrs;
4017 	srpt_target->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;
4018 	srpt_target->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;
4019 	srpt_target->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;
4020 	srpt_target->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;
4021 	srpt_target->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;
4022 	srpt_target->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;
4023 
4024 	ret = target_fabric_configfs_register(srpt_target);
4025 	if (ret < 0) {
4026 		printk(KERN_ERR "couldn't register\n");
4027 		goto out_free_target;
4028 	}
4029 
4030 	ret = ib_register_client(&srpt_client);
4031 	if (ret) {
4032 		printk(KERN_ERR "couldn't register IB client\n");
4033 		goto out_unregister_target;
4034 	}
4035 
4036 	return 0;
4037 
4038 out_unregister_target:
4039 	target_fabric_configfs_deregister(srpt_target);
4040 	srpt_target = NULL;
4041 out_free_target:
4042 	if (srpt_target)
4043 		target_fabric_configfs_free(srpt_target);
4044 out:
4045 	return ret;
4046 }
4047 
4048 static void __exit srpt_cleanup_module(void)
4049 {
4050 	ib_unregister_client(&srpt_client);
4051 	target_fabric_configfs_deregister(srpt_target);
4052 	srpt_target = NULL;
4053 }
4054 
4055 module_init(srpt_init_module);
4056 module_exit(srpt_cleanup_module);
4057