Merge branch 'for-next-merge' of git://git.kernel.org/pub/scm/linux/kernel/git/nab...
[~shefty/rdma-dev.git] / drivers / infiniband / ulp / srpt / ib_srpt.c
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 spinlock_t srpt_dev_lock;       /* Protects srpt_dev_list. */
73 static struct 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 out:
691         return ring;
692 }
693
694 /**
695  * srpt_free_ioctx_ring() - Free the ring of SRPT I/O context structures.
696  */
697 static void srpt_free_ioctx_ring(struct srpt_ioctx **ioctx_ring,
698                                  struct srpt_device *sdev, int ring_size,
699                                  int dma_size, enum dma_data_direction dir)
700 {
701         int i;
702
703         for (i = 0; i < ring_size; ++i)
704                 srpt_free_ioctx(sdev, ioctx_ring[i], dma_size, dir);
705         kfree(ioctx_ring);
706 }
707
708 /**
709  * srpt_get_cmd_state() - Get the state of a SCSI command.
710  */
711 static enum srpt_command_state srpt_get_cmd_state(struct srpt_send_ioctx *ioctx)
712 {
713         enum srpt_command_state state;
714         unsigned long flags;
715
716         BUG_ON(!ioctx);
717
718         spin_lock_irqsave(&ioctx->spinlock, flags);
719         state = ioctx->state;
720         spin_unlock_irqrestore(&ioctx->spinlock, flags);
721         return state;
722 }
723
724 /**
725  * srpt_set_cmd_state() - Set the state of a SCSI command.
726  *
727  * Does not modify the state of aborted commands. Returns the previous command
728  * state.
729  */
730 static enum srpt_command_state srpt_set_cmd_state(struct srpt_send_ioctx *ioctx,
731                                                   enum srpt_command_state new)
732 {
733         enum srpt_command_state previous;
734         unsigned long flags;
735
736         BUG_ON(!ioctx);
737
738         spin_lock_irqsave(&ioctx->spinlock, flags);
739         previous = ioctx->state;
740         if (previous != SRPT_STATE_DONE)
741                 ioctx->state = new;
742         spin_unlock_irqrestore(&ioctx->spinlock, flags);
743
744         return previous;
745 }
746
747 /**
748  * srpt_test_and_set_cmd_state() - Test and set the state of a command.
749  *
750  * Returns true if and only if the previous command state was equal to 'old'.
751  */
752 static bool srpt_test_and_set_cmd_state(struct srpt_send_ioctx *ioctx,
753                                         enum srpt_command_state old,
754                                         enum srpt_command_state new)
755 {
756         enum srpt_command_state previous;
757         unsigned long flags;
758
759         WARN_ON(!ioctx);
760         WARN_ON(old == SRPT_STATE_DONE);
761         WARN_ON(new == SRPT_STATE_NEW);
762
763         spin_lock_irqsave(&ioctx->spinlock, flags);
764         previous = ioctx->state;
765         if (previous == old)
766                 ioctx->state = new;
767         spin_unlock_irqrestore(&ioctx->spinlock, flags);
768         return previous == old;
769 }
770
771 /**
772  * srpt_post_recv() - Post an IB receive request.
773  */
774 static int srpt_post_recv(struct srpt_device *sdev,
775                           struct srpt_recv_ioctx *ioctx)
776 {
777         struct ib_sge list;
778         struct ib_recv_wr wr, *bad_wr;
779
780         BUG_ON(!sdev);
781         wr.wr_id = encode_wr_id(SRPT_RECV, ioctx->ioctx.index);
782
783         list.addr = ioctx->ioctx.dma;
784         list.length = srp_max_req_size;
785         list.lkey = sdev->mr->lkey;
786
787         wr.next = NULL;
788         wr.sg_list = &list;
789         wr.num_sge = 1;
790
791         return ib_post_srq_recv(sdev->srq, &wr, &bad_wr);
792 }
793
794 /**
795  * srpt_post_send() - Post an IB send request.
796  *
797  * Returns zero upon success and a non-zero value upon failure.
798  */
799 static int srpt_post_send(struct srpt_rdma_ch *ch,
800                           struct srpt_send_ioctx *ioctx, int len)
801 {
802         struct ib_sge list;
803         struct ib_send_wr wr, *bad_wr;
804         struct srpt_device *sdev = ch->sport->sdev;
805         int ret;
806
807         atomic_inc(&ch->req_lim);
808
809         ret = -ENOMEM;
810         if (unlikely(atomic_dec_return(&ch->sq_wr_avail) < 0)) {
811                 printk(KERN_WARNING "IB send queue full (needed 1)\n");
812                 goto out;
813         }
814
815         ib_dma_sync_single_for_device(sdev->device, ioctx->ioctx.dma, len,
816                                       DMA_TO_DEVICE);
817
818         list.addr = ioctx->ioctx.dma;
819         list.length = len;
820         list.lkey = sdev->mr->lkey;
821
822         wr.next = NULL;
823         wr.wr_id = encode_wr_id(SRPT_SEND, ioctx->ioctx.index);
824         wr.sg_list = &list;
825         wr.num_sge = 1;
826         wr.opcode = IB_WR_SEND;
827         wr.send_flags = IB_SEND_SIGNALED;
828
829         ret = ib_post_send(ch->qp, &wr, &bad_wr);
830
831 out:
832         if (ret < 0) {
833                 atomic_inc(&ch->sq_wr_avail);
834                 atomic_dec(&ch->req_lim);
835         }
836         return ret;
837 }
838
839 /**
840  * srpt_get_desc_tbl() - Parse the data descriptors of an SRP_CMD request.
841  * @ioctx: Pointer to the I/O context associated with the request.
842  * @srp_cmd: Pointer to the SRP_CMD request data.
843  * @dir: Pointer to the variable to which the transfer direction will be
844  *   written.
845  * @data_len: Pointer to the variable to which the total data length of all
846  *   descriptors in the SRP_CMD request will be written.
847  *
848  * This function initializes ioctx->nrbuf and ioctx->r_bufs.
849  *
850  * Returns -EINVAL when the SRP_CMD request contains inconsistent descriptors;
851  * -ENOMEM when memory allocation fails and zero upon success.
852  */
853 static int srpt_get_desc_tbl(struct srpt_send_ioctx *ioctx,
854                              struct srp_cmd *srp_cmd,
855                              enum dma_data_direction *dir, u64 *data_len)
856 {
857         struct srp_indirect_buf *idb;
858         struct srp_direct_buf *db;
859         unsigned add_cdb_offset;
860         int ret;
861
862         /*
863          * The pointer computations below will only be compiled correctly
864          * if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
865          * whether srp_cmd::add_data has been declared as a byte pointer.
866          */
867         BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0)
868                      && !__same_type(srp_cmd->add_data[0], (u8)0));
869
870         BUG_ON(!dir);
871         BUG_ON(!data_len);
872
873         ret = 0;
874         *data_len = 0;
875
876         /*
877          * The lower four bits of the buffer format field contain the DATA-IN
878          * buffer descriptor format, and the highest four bits contain the
879          * DATA-OUT buffer descriptor format.
880          */
881         *dir = DMA_NONE;
882         if (srp_cmd->buf_fmt & 0xf)
883                 /* DATA-IN: transfer data from target to initiator (read). */
884                 *dir = DMA_FROM_DEVICE;
885         else if (srp_cmd->buf_fmt >> 4)
886                 /* DATA-OUT: transfer data from initiator to target (write). */
887                 *dir = DMA_TO_DEVICE;
888
889         /*
890          * According to the SRP spec, the lower two bits of the 'ADDITIONAL
891          * CDB LENGTH' field are reserved and the size in bytes of this field
892          * is four times the value specified in bits 3..7. Hence the "& ~3".
893          */
894         add_cdb_offset = srp_cmd->add_cdb_len & ~3;
895         if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
896             ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
897                 ioctx->n_rbuf = 1;
898                 ioctx->rbufs = &ioctx->single_rbuf;
899
900                 db = (struct srp_direct_buf *)(srp_cmd->add_data
901                                                + add_cdb_offset);
902                 memcpy(ioctx->rbufs, db, sizeof *db);
903                 *data_len = be32_to_cpu(db->len);
904         } else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
905                    ((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
906                 idb = (struct srp_indirect_buf *)(srp_cmd->add_data
907                                                   + add_cdb_offset);
908
909                 ioctx->n_rbuf = be32_to_cpu(idb->table_desc.len) / sizeof *db;
910
911                 if (ioctx->n_rbuf >
912                     (srp_cmd->data_out_desc_cnt + srp_cmd->data_in_desc_cnt)) {
913                         printk(KERN_ERR "received unsupported SRP_CMD request"
914                                " type (%u out + %u in != %u / %zu)\n",
915                                srp_cmd->data_out_desc_cnt,
916                                srp_cmd->data_in_desc_cnt,
917                                be32_to_cpu(idb->table_desc.len),
918                                sizeof(*db));
919                         ioctx->n_rbuf = 0;
920                         ret = -EINVAL;
921                         goto out;
922                 }
923
924                 if (ioctx->n_rbuf == 1)
925                         ioctx->rbufs = &ioctx->single_rbuf;
926                 else {
927                         ioctx->rbufs =
928                                 kmalloc(ioctx->n_rbuf * sizeof *db, GFP_ATOMIC);
929                         if (!ioctx->rbufs) {
930                                 ioctx->n_rbuf = 0;
931                                 ret = -ENOMEM;
932                                 goto out;
933                         }
934                 }
935
936                 db = idb->desc_list;
937                 memcpy(ioctx->rbufs, db, ioctx->n_rbuf * sizeof *db);
938                 *data_len = be32_to_cpu(idb->len);
939         }
940 out:
941         return ret;
942 }
943
944 /**
945  * srpt_init_ch_qp() - Initialize queue pair attributes.
946  *
947  * Initialized the attributes of queue pair 'qp' by allowing local write,
948  * remote read and remote write. Also transitions 'qp' to state IB_QPS_INIT.
949  */
950 static int srpt_init_ch_qp(struct srpt_rdma_ch *ch, struct ib_qp *qp)
951 {
952         struct ib_qp_attr *attr;
953         int ret;
954
955         attr = kzalloc(sizeof *attr, GFP_KERNEL);
956         if (!attr)
957                 return -ENOMEM;
958
959         attr->qp_state = IB_QPS_INIT;
960         attr->qp_access_flags = IB_ACCESS_LOCAL_WRITE | IB_ACCESS_REMOTE_READ |
961             IB_ACCESS_REMOTE_WRITE;
962         attr->port_num = ch->sport->port;
963         attr->pkey_index = 0;
964
965         ret = ib_modify_qp(qp, attr,
966                            IB_QP_STATE | IB_QP_ACCESS_FLAGS | IB_QP_PORT |
967                            IB_QP_PKEY_INDEX);
968
969         kfree(attr);
970         return ret;
971 }
972
973 /**
974  * srpt_ch_qp_rtr() - Change the state of a channel to 'ready to receive' (RTR).
975  * @ch: channel of the queue pair.
976  * @qp: queue pair to change the state of.
977  *
978  * Returns zero upon success and a negative value upon failure.
979  *
980  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
981  * If this structure ever becomes larger, it might be necessary to allocate
982  * it dynamically instead of on the stack.
983  */
984 static int srpt_ch_qp_rtr(struct srpt_rdma_ch *ch, struct ib_qp *qp)
985 {
986         struct ib_qp_attr qp_attr;
987         int attr_mask;
988         int ret;
989
990         qp_attr.qp_state = IB_QPS_RTR;
991         ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
992         if (ret)
993                 goto out;
994
995         qp_attr.max_dest_rd_atomic = 4;
996
997         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
998
999 out:
1000         return ret;
1001 }
1002
1003 /**
1004  * srpt_ch_qp_rts() - Change the state of a channel to 'ready to send' (RTS).
1005  * @ch: channel of the queue pair.
1006  * @qp: queue pair to change the state of.
1007  *
1008  * Returns zero upon success and a negative value upon failure.
1009  *
1010  * Note: currently a struct ib_qp_attr takes 136 bytes on a 64-bit system.
1011  * If this structure ever becomes larger, it might be necessary to allocate
1012  * it dynamically instead of on the stack.
1013  */
1014 static int srpt_ch_qp_rts(struct srpt_rdma_ch *ch, struct ib_qp *qp)
1015 {
1016         struct ib_qp_attr qp_attr;
1017         int attr_mask;
1018         int ret;
1019
1020         qp_attr.qp_state = IB_QPS_RTS;
1021         ret = ib_cm_init_qp_attr(ch->cm_id, &qp_attr, &attr_mask);
1022         if (ret)
1023                 goto out;
1024
1025         qp_attr.max_rd_atomic = 4;
1026
1027         ret = ib_modify_qp(qp, &qp_attr, attr_mask);
1028
1029 out:
1030         return ret;
1031 }
1032
1033 /**
1034  * srpt_ch_qp_err() - Set the channel queue pair state to 'error'.
1035  */
1036 static int srpt_ch_qp_err(struct srpt_rdma_ch *ch)
1037 {
1038         struct ib_qp_attr qp_attr;
1039
1040         qp_attr.qp_state = IB_QPS_ERR;
1041         return ib_modify_qp(ch->qp, &qp_attr, IB_QP_STATE);
1042 }
1043
1044 /**
1045  * srpt_unmap_sg_to_ib_sge() - Unmap an IB SGE list.
1046  */
1047 static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1048                                     struct srpt_send_ioctx *ioctx)
1049 {
1050         struct scatterlist *sg;
1051         enum dma_data_direction dir;
1052
1053         BUG_ON(!ch);
1054         BUG_ON(!ioctx);
1055         BUG_ON(ioctx->n_rdma && !ioctx->rdma_ius);
1056
1057         while (ioctx->n_rdma)
1058                 kfree(ioctx->rdma_ius[--ioctx->n_rdma].sge);
1059
1060         kfree(ioctx->rdma_ius);
1061         ioctx->rdma_ius = NULL;
1062
1063         if (ioctx->mapped_sg_count) {
1064                 sg = ioctx->sg;
1065                 WARN_ON(!sg);
1066                 dir = ioctx->cmd.data_direction;
1067                 BUG_ON(dir == DMA_NONE);
1068                 ib_dma_unmap_sg(ch->sport->sdev->device, sg, ioctx->sg_cnt,
1069                                 opposite_dma_dir(dir));
1070                 ioctx->mapped_sg_count = 0;
1071         }
1072 }
1073
1074 /**
1075  * srpt_map_sg_to_ib_sge() - Map an SG list to an IB SGE list.
1076  */
1077 static int srpt_map_sg_to_ib_sge(struct srpt_rdma_ch *ch,
1078                                  struct srpt_send_ioctx *ioctx)
1079 {
1080         struct se_cmd *cmd;
1081         struct scatterlist *sg, *sg_orig;
1082         int sg_cnt;
1083         enum dma_data_direction dir;
1084         struct rdma_iu *riu;
1085         struct srp_direct_buf *db;
1086         dma_addr_t dma_addr;
1087         struct ib_sge *sge;
1088         u64 raddr;
1089         u32 rsize;
1090         u32 tsize;
1091         u32 dma_len;
1092         int count, nrdma;
1093         int i, j, k;
1094
1095         BUG_ON(!ch);
1096         BUG_ON(!ioctx);
1097         cmd = &ioctx->cmd;
1098         dir = cmd->data_direction;
1099         BUG_ON(dir == DMA_NONE);
1100
1101         transport_do_task_sg_chain(cmd);
1102         ioctx->sg = sg = sg_orig = cmd->t_tasks_sg_chained;
1103         ioctx->sg_cnt = sg_cnt = cmd->t_tasks_sg_chained_no;
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                 atomic_set(&ioctx->cmd.transport_lun_stop, 1);
1381                 transport_generic_handle_data(&ioctx->cmd);
1382                 break;
1383         case SRPT_STATE_CMD_RSP_SENT:
1384                 /*
1385                  * SRP_RSP sending failed or the SRP_RSP send completion has
1386                  * not been received in time.
1387                  */
1388                 srpt_unmap_sg_to_ib_sge(ioctx->ch, ioctx);
1389                 atomic_set(&ioctx->cmd.transport_lun_stop, 1);
1390                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1391                 break;
1392         case SRPT_STATE_MGMT_RSP_SENT:
1393                 srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1394                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1395                 break;
1396         default:
1397                 WARN_ON("ERROR: unexpected command state");
1398                 break;
1399         }
1400
1401 out:
1402         return state;
1403 }
1404
1405 /**
1406  * srpt_handle_send_err_comp() - Process an IB_WC_SEND error completion.
1407  */
1408 static void srpt_handle_send_err_comp(struct srpt_rdma_ch *ch, u64 wr_id)
1409 {
1410         struct srpt_send_ioctx *ioctx;
1411         enum srpt_command_state state;
1412         struct se_cmd *cmd;
1413         u32 index;
1414
1415         atomic_inc(&ch->sq_wr_avail);
1416
1417         index = idx_from_wr_id(wr_id);
1418         ioctx = ch->ioctx_ring[index];
1419         state = srpt_get_cmd_state(ioctx);
1420         cmd = &ioctx->cmd;
1421
1422         WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1423                 && state != SRPT_STATE_MGMT_RSP_SENT
1424                 && state != SRPT_STATE_NEED_DATA
1425                 && state != SRPT_STATE_DONE);
1426
1427         /* If SRP_RSP sending failed, undo the ch->req_lim change. */
1428         if (state == SRPT_STATE_CMD_RSP_SENT
1429             || state == SRPT_STATE_MGMT_RSP_SENT)
1430                 atomic_dec(&ch->req_lim);
1431
1432         srpt_abort_cmd(ioctx);
1433 }
1434
1435 /**
1436  * srpt_handle_send_comp() - Process an IB send completion notification.
1437  */
1438 static void srpt_handle_send_comp(struct srpt_rdma_ch *ch,
1439                                   struct srpt_send_ioctx *ioctx)
1440 {
1441         enum srpt_command_state state;
1442
1443         atomic_inc(&ch->sq_wr_avail);
1444
1445         state = srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
1446
1447         if (WARN_ON(state != SRPT_STATE_CMD_RSP_SENT
1448                     && state != SRPT_STATE_MGMT_RSP_SENT
1449                     && state != SRPT_STATE_DONE))
1450                 pr_debug("state = %d\n", state);
1451
1452         if (state != SRPT_STATE_DONE)
1453                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1454         else
1455                 printk(KERN_ERR "IB completion has been received too late for"
1456                        " wr_id = %u.\n", ioctx->ioctx.index);
1457 }
1458
1459 /**
1460  * srpt_handle_rdma_comp() - Process an IB RDMA completion notification.
1461  *
1462  * Note: transport_generic_handle_data() is asynchronous so unmapping the
1463  * data that has been transferred via IB RDMA must be postponed until the
1464  * check_stop_free() callback.
1465  */
1466 static void srpt_handle_rdma_comp(struct srpt_rdma_ch *ch,
1467                                   struct srpt_send_ioctx *ioctx,
1468                                   enum srpt_opcode opcode)
1469 {
1470         WARN_ON(ioctx->n_rdma <= 0);
1471         atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1472
1473         if (opcode == SRPT_RDMA_READ_LAST) {
1474                 if (srpt_test_and_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA,
1475                                                 SRPT_STATE_DATA_IN))
1476                         transport_generic_handle_data(&ioctx->cmd);
1477                 else
1478                         printk(KERN_ERR "%s[%d]: wrong state = %d\n", __func__,
1479                                __LINE__, srpt_get_cmd_state(ioctx));
1480         } else if (opcode == SRPT_RDMA_ABORT) {
1481                 ioctx->rdma_aborted = true;
1482         } else {
1483                 WARN(true, "unexpected opcode %d\n", opcode);
1484         }
1485 }
1486
1487 /**
1488  * srpt_handle_rdma_err_comp() - Process an IB RDMA error completion.
1489  */
1490 static void srpt_handle_rdma_err_comp(struct srpt_rdma_ch *ch,
1491                                       struct srpt_send_ioctx *ioctx,
1492                                       enum srpt_opcode opcode)
1493 {
1494         struct se_cmd *cmd;
1495         enum srpt_command_state state;
1496
1497         cmd = &ioctx->cmd;
1498         state = srpt_get_cmd_state(ioctx);
1499         switch (opcode) {
1500         case SRPT_RDMA_READ_LAST:
1501                 if (ioctx->n_rdma <= 0) {
1502                         printk(KERN_ERR "Received invalid RDMA read"
1503                                " error completion with idx %d\n",
1504                                ioctx->ioctx.index);
1505                         break;
1506                 }
1507                 atomic_add(ioctx->n_rdma, &ch->sq_wr_avail);
1508                 if (state == SRPT_STATE_NEED_DATA)
1509                         srpt_abort_cmd(ioctx);
1510                 else
1511                         printk(KERN_ERR "%s[%d]: wrong state = %d\n",
1512                                __func__, __LINE__, state);
1513                 break;
1514         case SRPT_RDMA_WRITE_LAST:
1515                 atomic_set(&ioctx->cmd.transport_lun_stop, 1);
1516                 break;
1517         default:
1518                 printk(KERN_ERR "%s[%d]: opcode = %u\n", __func__,
1519                        __LINE__, opcode);
1520                 break;
1521         }
1522 }
1523
1524 /**
1525  * srpt_build_cmd_rsp() - Build an SRP_RSP response.
1526  * @ch: RDMA channel through which the request has been received.
1527  * @ioctx: I/O context associated with the SRP_CMD request. The response will
1528  *   be built in the buffer ioctx->buf points at and hence this function will
1529  *   overwrite the request data.
1530  * @tag: tag of the request for which this response is being generated.
1531  * @status: value for the STATUS field of the SRP_RSP information unit.
1532  *
1533  * Returns the size in bytes of the SRP_RSP response.
1534  *
1535  * An SRP_RSP response contains a SCSI status or service response. See also
1536  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1537  * response. See also SPC-2 for more information about sense data.
1538  */
1539 static int srpt_build_cmd_rsp(struct srpt_rdma_ch *ch,
1540                               struct srpt_send_ioctx *ioctx, u64 tag,
1541                               int status)
1542 {
1543         struct srp_rsp *srp_rsp;
1544         const u8 *sense_data;
1545         int sense_data_len, max_sense_len;
1546
1547         /*
1548          * The lowest bit of all SAM-3 status codes is zero (see also
1549          * paragraph 5.3 in SAM-3).
1550          */
1551         WARN_ON(status & 1);
1552
1553         srp_rsp = ioctx->ioctx.buf;
1554         BUG_ON(!srp_rsp);
1555
1556         sense_data = ioctx->sense_data;
1557         sense_data_len = ioctx->cmd.scsi_sense_length;
1558         WARN_ON(sense_data_len > sizeof(ioctx->sense_data));
1559
1560         memset(srp_rsp, 0, sizeof *srp_rsp);
1561         srp_rsp->opcode = SRP_RSP;
1562         srp_rsp->req_lim_delta =
1563                 __constant_cpu_to_be32(1 + atomic_xchg(&ch->req_lim_delta, 0));
1564         srp_rsp->tag = tag;
1565         srp_rsp->status = status;
1566
1567         if (sense_data_len) {
1568                 BUILD_BUG_ON(MIN_MAX_RSP_SIZE <= sizeof(*srp_rsp));
1569                 max_sense_len = ch->max_ti_iu_len - sizeof(*srp_rsp);
1570                 if (sense_data_len > max_sense_len) {
1571                         printk(KERN_WARNING "truncated sense data from %d to %d"
1572                                " bytes\n", sense_data_len, max_sense_len);
1573                         sense_data_len = max_sense_len;
1574                 }
1575
1576                 srp_rsp->flags |= SRP_RSP_FLAG_SNSVALID;
1577                 srp_rsp->sense_data_len = cpu_to_be32(sense_data_len);
1578                 memcpy(srp_rsp + 1, sense_data, sense_data_len);
1579         }
1580
1581         return sizeof(*srp_rsp) + sense_data_len;
1582 }
1583
1584 /**
1585  * srpt_build_tskmgmt_rsp() - Build a task management response.
1586  * @ch:       RDMA channel through which the request has been received.
1587  * @ioctx:    I/O context in which the SRP_RSP response will be built.
1588  * @rsp_code: RSP_CODE that will be stored in the response.
1589  * @tag:      Tag of the request for which this response is being generated.
1590  *
1591  * Returns the size in bytes of the SRP_RSP response.
1592  *
1593  * An SRP_RSP response contains a SCSI status or service response. See also
1594  * section 6.9 in the SRP r16a document for the format of an SRP_RSP
1595  * response.
1596  */
1597 static int srpt_build_tskmgmt_rsp(struct srpt_rdma_ch *ch,
1598                                   struct srpt_send_ioctx *ioctx,
1599                                   u8 rsp_code, u64 tag)
1600 {
1601         struct srp_rsp *srp_rsp;
1602         int resp_data_len;
1603         int resp_len;
1604
1605         resp_data_len = (rsp_code == SRP_TSK_MGMT_SUCCESS) ? 0 : 4;
1606         resp_len = sizeof(*srp_rsp) + resp_data_len;
1607
1608         srp_rsp = ioctx->ioctx.buf;
1609         BUG_ON(!srp_rsp);
1610         memset(srp_rsp, 0, sizeof *srp_rsp);
1611
1612         srp_rsp->opcode = SRP_RSP;
1613         srp_rsp->req_lim_delta = __constant_cpu_to_be32(1
1614                                     + atomic_xchg(&ch->req_lim_delta, 0));
1615         srp_rsp->tag = tag;
1616
1617         if (rsp_code != SRP_TSK_MGMT_SUCCESS) {
1618                 srp_rsp->flags |= SRP_RSP_FLAG_RSPVALID;
1619                 srp_rsp->resp_data_len = cpu_to_be32(resp_data_len);
1620                 srp_rsp->data[3] = rsp_code;
1621         }
1622
1623         return resp_len;
1624 }
1625
1626 #define NO_SUCH_LUN ((uint64_t)-1LL)
1627
1628 /*
1629  * SCSI LUN addressing method. See also SAM-2 and the section about
1630  * eight byte LUNs.
1631  */
1632 enum scsi_lun_addr_method {
1633         SCSI_LUN_ADDR_METHOD_PERIPHERAL   = 0,
1634         SCSI_LUN_ADDR_METHOD_FLAT         = 1,
1635         SCSI_LUN_ADDR_METHOD_LUN          = 2,
1636         SCSI_LUN_ADDR_METHOD_EXTENDED_LUN = 3,
1637 };
1638
1639 /*
1640  * srpt_unpack_lun() - Convert from network LUN to linear LUN.
1641  *
1642  * Convert an 2-byte, 4-byte, 6-byte or 8-byte LUN structure in network byte
1643  * order (big endian) to a linear LUN. Supports three LUN addressing methods:
1644  * peripheral, flat and logical unit. See also SAM-2, section 4.9.4 (page 40).
1645  */
1646 static uint64_t srpt_unpack_lun(const uint8_t *lun, int len)
1647 {
1648         uint64_t res = NO_SUCH_LUN;
1649         int addressing_method;
1650
1651         if (unlikely(len < 2)) {
1652                 printk(KERN_ERR "Illegal LUN length %d, expected 2 bytes or "
1653                        "more", len);
1654                 goto out;
1655         }
1656
1657         switch (len) {
1658         case 8:
1659                 if ((*((__be64 *)lun) &
1660                      __constant_cpu_to_be64(0x0000FFFFFFFFFFFFLL)) != 0)
1661                         goto out_err;
1662                 break;
1663         case 4:
1664                 if (*((__be16 *)&lun[2]) != 0)
1665                         goto out_err;
1666                 break;
1667         case 6:
1668                 if (*((__be32 *)&lun[2]) != 0)
1669                         goto out_err;
1670                 break;
1671         case 2:
1672                 break;
1673         default:
1674                 goto out_err;
1675         }
1676
1677         addressing_method = (*lun) >> 6; /* highest two bits of byte 0 */
1678         switch (addressing_method) {
1679         case SCSI_LUN_ADDR_METHOD_PERIPHERAL:
1680         case SCSI_LUN_ADDR_METHOD_FLAT:
1681         case SCSI_LUN_ADDR_METHOD_LUN:
1682                 res = *(lun + 1) | (((*lun) & 0x3f) << 8);
1683                 break;
1684
1685         case SCSI_LUN_ADDR_METHOD_EXTENDED_LUN:
1686         default:
1687                 printk(KERN_ERR "Unimplemented LUN addressing method %u",
1688                        addressing_method);
1689                 break;
1690         }
1691
1692 out:
1693         return res;
1694
1695 out_err:
1696         printk(KERN_ERR "Support for multi-level LUNs has not yet been"
1697                " implemented");
1698         goto out;
1699 }
1700
1701 static int srpt_check_stop_free(struct se_cmd *cmd)
1702 {
1703         struct srpt_send_ioctx *ioctx;
1704
1705         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
1706         return kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
1707 }
1708
1709 /**
1710  * srpt_handle_cmd() - Process SRP_CMD.
1711  */
1712 static int srpt_handle_cmd(struct srpt_rdma_ch *ch,
1713                            struct srpt_recv_ioctx *recv_ioctx,
1714                            struct srpt_send_ioctx *send_ioctx)
1715 {
1716         struct se_cmd *cmd;
1717         struct srp_cmd *srp_cmd;
1718         uint64_t unpacked_lun;
1719         u64 data_len;
1720         enum dma_data_direction dir;
1721         int ret;
1722
1723         BUG_ON(!send_ioctx);
1724
1725         srp_cmd = recv_ioctx->ioctx.buf;
1726         kref_get(&send_ioctx->kref);
1727         cmd = &send_ioctx->cmd;
1728         send_ioctx->tag = srp_cmd->tag;
1729
1730         switch (srp_cmd->task_attr) {
1731         case SRP_CMD_SIMPLE_Q:
1732                 cmd->sam_task_attr = MSG_SIMPLE_TAG;
1733                 break;
1734         case SRP_CMD_ORDERED_Q:
1735         default:
1736                 cmd->sam_task_attr = MSG_ORDERED_TAG;
1737                 break;
1738         case SRP_CMD_HEAD_OF_Q:
1739                 cmd->sam_task_attr = MSG_HEAD_TAG;
1740                 break;
1741         case SRP_CMD_ACA:
1742                 cmd->sam_task_attr = MSG_ACA_TAG;
1743                 break;
1744         }
1745
1746         ret = srpt_get_desc_tbl(send_ioctx, srp_cmd, &dir, &data_len);
1747         if (ret) {
1748                 printk(KERN_ERR "0x%llx: parsing SRP descriptor table failed.\n",
1749                        srp_cmd->tag);
1750                 cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1751                 cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1752                 goto send_sense;
1753         }
1754
1755         cmd->data_length = data_len;
1756         cmd->data_direction = dir;
1757         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_cmd->lun,
1758                                        sizeof(srp_cmd->lun));
1759         if (transport_lookup_cmd_lun(cmd, unpacked_lun) < 0)
1760                 goto send_sense;
1761         ret = transport_generic_allocate_tasks(cmd, srp_cmd->cdb);
1762         if (cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
1763                 srpt_queue_status(cmd);
1764         else if (cmd->se_cmd_flags & SCF_SCSI_CDB_EXCEPTION)
1765                 goto send_sense;
1766         else
1767                 WARN_ON_ONCE(ret);
1768
1769         transport_handle_cdb_direct(cmd);
1770         return 0;
1771
1772 send_sense:
1773         transport_send_check_condition_and_sense(cmd, cmd->scsi_sense_reason,
1774                                                  0);
1775         return -1;
1776 }
1777
1778 /**
1779  * srpt_rx_mgmt_fn_tag() - Process a task management function by tag.
1780  * @ch: RDMA channel of the task management request.
1781  * @fn: Task management function to perform.
1782  * @req_tag: Tag of the SRP task management request.
1783  * @mgmt_ioctx: I/O context of the task management request.
1784  *
1785  * Returns zero if the target core will process the task management
1786  * request asynchronously.
1787  *
1788  * Note: It is assumed that the initiator serializes tag-based task management
1789  * requests.
1790  */
1791 static int srpt_rx_mgmt_fn_tag(struct srpt_send_ioctx *ioctx, u64 tag)
1792 {
1793         struct srpt_device *sdev;
1794         struct srpt_rdma_ch *ch;
1795         struct srpt_send_ioctx *target;
1796         int ret, i;
1797
1798         ret = -EINVAL;
1799         ch = ioctx->ch;
1800         BUG_ON(!ch);
1801         BUG_ON(!ch->sport);
1802         sdev = ch->sport->sdev;
1803         BUG_ON(!sdev);
1804         spin_lock_irq(&sdev->spinlock);
1805         for (i = 0; i < ch->rq_size; ++i) {
1806                 target = ch->ioctx_ring[i];
1807                 if (target->cmd.se_lun == ioctx->cmd.se_lun &&
1808                     target->tag == tag &&
1809                     srpt_get_cmd_state(target) != SRPT_STATE_DONE) {
1810                         ret = 0;
1811                         /* now let the target core abort &target->cmd; */
1812                         break;
1813                 }
1814         }
1815         spin_unlock_irq(&sdev->spinlock);
1816         return ret;
1817 }
1818
1819 static int srp_tmr_to_tcm(int fn)
1820 {
1821         switch (fn) {
1822         case SRP_TSK_ABORT_TASK:
1823                 return TMR_ABORT_TASK;
1824         case SRP_TSK_ABORT_TASK_SET:
1825                 return TMR_ABORT_TASK_SET;
1826         case SRP_TSK_CLEAR_TASK_SET:
1827                 return TMR_CLEAR_TASK_SET;
1828         case SRP_TSK_LUN_RESET:
1829                 return TMR_LUN_RESET;
1830         case SRP_TSK_CLEAR_ACA:
1831                 return TMR_CLEAR_ACA;
1832         default:
1833                 return -1;
1834         }
1835 }
1836
1837 /**
1838  * srpt_handle_tsk_mgmt() - Process an SRP_TSK_MGMT information unit.
1839  *
1840  * Returns 0 if and only if the request will be processed by the target core.
1841  *
1842  * For more information about SRP_TSK_MGMT information units, see also section
1843  * 6.7 in the SRP r16a document.
1844  */
1845 static void srpt_handle_tsk_mgmt(struct srpt_rdma_ch *ch,
1846                                  struct srpt_recv_ioctx *recv_ioctx,
1847                                  struct srpt_send_ioctx *send_ioctx)
1848 {
1849         struct srp_tsk_mgmt *srp_tsk;
1850         struct se_cmd *cmd;
1851         uint64_t unpacked_lun;
1852         int tcm_tmr;
1853         int res;
1854
1855         BUG_ON(!send_ioctx);
1856
1857         srp_tsk = recv_ioctx->ioctx.buf;
1858         cmd = &send_ioctx->cmd;
1859
1860         pr_debug("recv tsk_mgmt fn %d for task_tag %lld and cmd tag %lld"
1861                  " cm_id %p sess %p\n", srp_tsk->tsk_mgmt_func,
1862                  srp_tsk->task_tag, srp_tsk->tag, ch->cm_id, ch->sess);
1863
1864         srpt_set_cmd_state(send_ioctx, SRPT_STATE_MGMT);
1865         send_ioctx->tag = srp_tsk->tag;
1866         tcm_tmr = srp_tmr_to_tcm(srp_tsk->tsk_mgmt_func);
1867         if (tcm_tmr < 0) {
1868                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1869                 send_ioctx->cmd.se_tmr_req->response =
1870                         TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
1871                 goto process_tmr;
1872         }
1873         cmd->se_tmr_req = core_tmr_alloc_req(cmd, NULL, tcm_tmr, GFP_KERNEL);
1874         if (!cmd->se_tmr_req) {
1875                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1876                 send_ioctx->cmd.se_tmr_req->response = TMR_FUNCTION_REJECTED;
1877                 goto process_tmr;
1878         }
1879
1880         unpacked_lun = srpt_unpack_lun((uint8_t *)&srp_tsk->lun,
1881                                        sizeof(srp_tsk->lun));
1882         res = transport_lookup_tmr_lun(&send_ioctx->cmd, unpacked_lun);
1883         if (res) {
1884                 pr_debug("rejecting TMR for LUN %lld\n", unpacked_lun);
1885                 send_ioctx->cmd.se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1886                 send_ioctx->cmd.se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1887                 goto process_tmr;
1888         }
1889
1890         if (srp_tsk->tsk_mgmt_func == SRP_TSK_ABORT_TASK)
1891                 srpt_rx_mgmt_fn_tag(send_ioctx, srp_tsk->task_tag);
1892
1893 process_tmr:
1894         kref_get(&send_ioctx->kref);
1895         if (!(send_ioctx->cmd.se_cmd_flags & SCF_SCSI_CDB_EXCEPTION))
1896                 transport_generic_handle_tmr(&send_ioctx->cmd);
1897         else
1898                 transport_send_check_condition_and_sense(cmd,
1899                                                 cmd->scsi_sense_reason, 0);
1900
1901 }
1902
1903 /**
1904  * srpt_handle_new_iu() - Process a newly received information unit.
1905  * @ch:    RDMA channel through which the information unit has been received.
1906  * @ioctx: SRPT I/O context associated with the information unit.
1907  */
1908 static void srpt_handle_new_iu(struct srpt_rdma_ch *ch,
1909                                struct srpt_recv_ioctx *recv_ioctx,
1910                                struct srpt_send_ioctx *send_ioctx)
1911 {
1912         struct srp_cmd *srp_cmd;
1913         enum rdma_ch_state ch_state;
1914
1915         BUG_ON(!ch);
1916         BUG_ON(!recv_ioctx);
1917
1918         ib_dma_sync_single_for_cpu(ch->sport->sdev->device,
1919                                    recv_ioctx->ioctx.dma, srp_max_req_size,
1920                                    DMA_FROM_DEVICE);
1921
1922         ch_state = srpt_get_ch_state(ch);
1923         if (unlikely(ch_state == CH_CONNECTING)) {
1924                 list_add_tail(&recv_ioctx->wait_list, &ch->cmd_wait_list);
1925                 goto out;
1926         }
1927
1928         if (unlikely(ch_state != CH_LIVE))
1929                 goto out;
1930
1931         srp_cmd = recv_ioctx->ioctx.buf;
1932         if (srp_cmd->opcode == SRP_CMD || srp_cmd->opcode == SRP_TSK_MGMT) {
1933                 if (!send_ioctx)
1934                         send_ioctx = srpt_get_send_ioctx(ch);
1935                 if (unlikely(!send_ioctx)) {
1936                         list_add_tail(&recv_ioctx->wait_list,
1937                                       &ch->cmd_wait_list);
1938                         goto out;
1939                 }
1940         }
1941
1942         transport_init_se_cmd(&send_ioctx->cmd, &srpt_target->tf_ops, ch->sess,
1943                               0, DMA_NONE, MSG_SIMPLE_TAG,
1944                               send_ioctx->sense_data);
1945
1946         switch (srp_cmd->opcode) {
1947         case SRP_CMD:
1948                 srpt_handle_cmd(ch, recv_ioctx, send_ioctx);
1949                 break;
1950         case SRP_TSK_MGMT:
1951                 srpt_handle_tsk_mgmt(ch, recv_ioctx, send_ioctx);
1952                 break;
1953         case SRP_I_LOGOUT:
1954                 printk(KERN_ERR "Not yet implemented: SRP_I_LOGOUT\n");
1955                 break;
1956         case SRP_CRED_RSP:
1957                 pr_debug("received SRP_CRED_RSP\n");
1958                 break;
1959         case SRP_AER_RSP:
1960                 pr_debug("received SRP_AER_RSP\n");
1961                 break;
1962         case SRP_RSP:
1963                 printk(KERN_ERR "Received SRP_RSP\n");
1964                 break;
1965         default:
1966                 printk(KERN_ERR "received IU with unknown opcode 0x%x\n",
1967                        srp_cmd->opcode);
1968                 break;
1969         }
1970
1971         srpt_post_recv(ch->sport->sdev, recv_ioctx);
1972 out:
1973         return;
1974 }
1975
1976 static void srpt_process_rcv_completion(struct ib_cq *cq,
1977                                         struct srpt_rdma_ch *ch,
1978                                         struct ib_wc *wc)
1979 {
1980         struct srpt_device *sdev = ch->sport->sdev;
1981         struct srpt_recv_ioctx *ioctx;
1982         u32 index;
1983
1984         index = idx_from_wr_id(wc->wr_id);
1985         if (wc->status == IB_WC_SUCCESS) {
1986                 int req_lim;
1987
1988                 req_lim = atomic_dec_return(&ch->req_lim);
1989                 if (unlikely(req_lim < 0))
1990                         printk(KERN_ERR "req_lim = %d < 0\n", req_lim);
1991                 ioctx = sdev->ioctx_ring[index];
1992                 srpt_handle_new_iu(ch, ioctx, NULL);
1993         } else {
1994                 printk(KERN_INFO "receiving failed for idx %u with status %d\n",
1995                        index, wc->status);
1996         }
1997 }
1998
1999 /**
2000  * srpt_process_send_completion() - Process an IB send completion.
2001  *
2002  * Note: Although this has not yet been observed during tests, at least in
2003  * theory it is possible that the srpt_get_send_ioctx() call invoked by
2004  * srpt_handle_new_iu() fails. This is possible because the req_lim_delta
2005  * value in each response is set to one, and it is possible that this response
2006  * makes the initiator send a new request before the send completion for that
2007  * response has been processed. This could e.g. happen if the call to
2008  * srpt_put_send_iotcx() is delayed because of a higher priority interrupt or
2009  * if IB retransmission causes generation of the send completion to be
2010  * delayed. Incoming information units for which srpt_get_send_ioctx() fails
2011  * are queued on cmd_wait_list. The code below processes these delayed
2012  * requests one at a time.
2013  */
2014 static void srpt_process_send_completion(struct ib_cq *cq,
2015                                          struct srpt_rdma_ch *ch,
2016                                          struct ib_wc *wc)
2017 {
2018         struct srpt_send_ioctx *send_ioctx;
2019         uint32_t index;
2020         enum srpt_opcode opcode;
2021
2022         index = idx_from_wr_id(wc->wr_id);
2023         opcode = opcode_from_wr_id(wc->wr_id);
2024         send_ioctx = ch->ioctx_ring[index];
2025         if (wc->status == IB_WC_SUCCESS) {
2026                 if (opcode == SRPT_SEND)
2027                         srpt_handle_send_comp(ch, send_ioctx);
2028                 else {
2029                         WARN_ON(opcode != SRPT_RDMA_ABORT &&
2030                                 wc->opcode != IB_WC_RDMA_READ);
2031                         srpt_handle_rdma_comp(ch, send_ioctx, opcode);
2032                 }
2033         } else {
2034                 if (opcode == SRPT_SEND) {
2035                         printk(KERN_INFO "sending response for idx %u failed"
2036                                " with status %d\n", index, wc->status);
2037                         srpt_handle_send_err_comp(ch, wc->wr_id);
2038                 } else if (opcode != SRPT_RDMA_MID) {
2039                         printk(KERN_INFO "RDMA t %d for idx %u failed with"
2040                                 " status %d", opcode, index, wc->status);
2041                         srpt_handle_rdma_err_comp(ch, send_ioctx, opcode);
2042                 }
2043         }
2044
2045         while (unlikely(opcode == SRPT_SEND
2046                         && !list_empty(&ch->cmd_wait_list)
2047                         && srpt_get_ch_state(ch) == CH_LIVE
2048                         && (send_ioctx = srpt_get_send_ioctx(ch)) != NULL)) {
2049                 struct srpt_recv_ioctx *recv_ioctx;
2050
2051                 recv_ioctx = list_first_entry(&ch->cmd_wait_list,
2052                                               struct srpt_recv_ioctx,
2053                                               wait_list);
2054                 list_del(&recv_ioctx->wait_list);
2055                 srpt_handle_new_iu(ch, recv_ioctx, send_ioctx);
2056         }
2057 }
2058
2059 static void srpt_process_completion(struct ib_cq *cq, struct srpt_rdma_ch *ch)
2060 {
2061         struct ib_wc *const wc = ch->wc;
2062         int i, n;
2063
2064         WARN_ON(cq != ch->cq);
2065
2066         ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
2067         while ((n = ib_poll_cq(cq, ARRAY_SIZE(ch->wc), wc)) > 0) {
2068                 for (i = 0; i < n; i++) {
2069                         if (opcode_from_wr_id(wc[i].wr_id) == SRPT_RECV)
2070                                 srpt_process_rcv_completion(cq, ch, &wc[i]);
2071                         else
2072                                 srpt_process_send_completion(cq, ch, &wc[i]);
2073                 }
2074         }
2075 }
2076
2077 /**
2078  * srpt_completion() - IB completion queue callback function.
2079  *
2080  * Notes:
2081  * - It is guaranteed that a completion handler will never be invoked
2082  *   concurrently on two different CPUs for the same completion queue. See also
2083  *   Documentation/infiniband/core_locking.txt and the implementation of
2084  *   handle_edge_irq() in kernel/irq/chip.c.
2085  * - When threaded IRQs are enabled, completion handlers are invoked in thread
2086  *   context instead of interrupt context.
2087  */
2088 static void srpt_completion(struct ib_cq *cq, void *ctx)
2089 {
2090         struct srpt_rdma_ch *ch = ctx;
2091
2092         wake_up_interruptible(&ch->wait_queue);
2093 }
2094
2095 static int srpt_compl_thread(void *arg)
2096 {
2097         struct srpt_rdma_ch *ch;
2098
2099         /* Hibernation / freezing of the SRPT kernel thread is not supported. */
2100         current->flags |= PF_NOFREEZE;
2101
2102         ch = arg;
2103         BUG_ON(!ch);
2104         printk(KERN_INFO "Session %s: kernel thread %s (PID %d) started\n",
2105                ch->sess_name, ch->thread->comm, current->pid);
2106         while (!kthread_should_stop()) {
2107                 wait_event_interruptible(ch->wait_queue,
2108                         (srpt_process_completion(ch->cq, ch),
2109                          kthread_should_stop()));
2110         }
2111         printk(KERN_INFO "Session %s: kernel thread %s (PID %d) stopped\n",
2112                ch->sess_name, ch->thread->comm, current->pid);
2113         return 0;
2114 }
2115
2116 /**
2117  * srpt_create_ch_ib() - Create receive and send completion queues.
2118  */
2119 static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
2120 {
2121         struct ib_qp_init_attr *qp_init;
2122         struct srpt_port *sport = ch->sport;
2123         struct srpt_device *sdev = sport->sdev;
2124         u32 srp_sq_size = sport->port_attrib.srp_sq_size;
2125         int ret;
2126
2127         WARN_ON(ch->rq_size < 1);
2128
2129         ret = -ENOMEM;
2130         qp_init = kzalloc(sizeof *qp_init, GFP_KERNEL);
2131         if (!qp_init)
2132                 goto out;
2133
2134         ch->cq = ib_create_cq(sdev->device, srpt_completion, NULL, ch,
2135                               ch->rq_size + srp_sq_size, 0);
2136         if (IS_ERR(ch->cq)) {
2137                 ret = PTR_ERR(ch->cq);
2138                 printk(KERN_ERR "failed to create CQ cqe= %d ret= %d\n",
2139                        ch->rq_size + srp_sq_size, ret);
2140                 goto out;
2141         }
2142
2143         qp_init->qp_context = (void *)ch;
2144         qp_init->event_handler
2145                 = (void(*)(struct ib_event *, void*))srpt_qp_event;
2146         qp_init->send_cq = ch->cq;
2147         qp_init->recv_cq = ch->cq;
2148         qp_init->srq = sdev->srq;
2149         qp_init->sq_sig_type = IB_SIGNAL_REQ_WR;
2150         qp_init->qp_type = IB_QPT_RC;
2151         qp_init->cap.max_send_wr = srp_sq_size;
2152         qp_init->cap.max_send_sge = SRPT_DEF_SG_PER_WQE;
2153
2154         ch->qp = ib_create_qp(sdev->pd, qp_init);
2155         if (IS_ERR(ch->qp)) {
2156                 ret = PTR_ERR(ch->qp);
2157                 printk(KERN_ERR "failed to create_qp ret= %d\n", ret);
2158                 goto err_destroy_cq;
2159         }
2160
2161         atomic_set(&ch->sq_wr_avail, qp_init->cap.max_send_wr);
2162
2163         pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
2164                  __func__, ch->cq->cqe, qp_init->cap.max_send_sge,
2165                  qp_init->cap.max_send_wr, ch->cm_id);
2166
2167         ret = srpt_init_ch_qp(ch, ch->qp);
2168         if (ret)
2169                 goto err_destroy_qp;
2170
2171         init_waitqueue_head(&ch->wait_queue);
2172
2173         pr_debug("creating thread for session %s\n", ch->sess_name);
2174
2175         ch->thread = kthread_run(srpt_compl_thread, ch, "ib_srpt_compl");
2176         if (IS_ERR(ch->thread)) {
2177                 printk(KERN_ERR "failed to create kernel thread %ld\n",
2178                        PTR_ERR(ch->thread));
2179                 ch->thread = NULL;
2180                 goto err_destroy_qp;
2181         }
2182
2183 out:
2184         kfree(qp_init);
2185         return ret;
2186
2187 err_destroy_qp:
2188         ib_destroy_qp(ch->qp);
2189 err_destroy_cq:
2190         ib_destroy_cq(ch->cq);
2191         goto out;
2192 }
2193
2194 static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
2195 {
2196         if (ch->thread)
2197                 kthread_stop(ch->thread);
2198
2199         ib_destroy_qp(ch->qp);
2200         ib_destroy_cq(ch->cq);
2201 }
2202
2203 /**
2204  * __srpt_close_ch() - Close an RDMA channel by setting the QP error state.
2205  *
2206  * Reset the QP and make sure all resources associated with the channel will
2207  * be deallocated at an appropriate time.
2208  *
2209  * Note: The caller must hold ch->sport->sdev->spinlock.
2210  */
2211 static void __srpt_close_ch(struct srpt_rdma_ch *ch)
2212 {
2213         struct srpt_device *sdev;
2214         enum rdma_ch_state prev_state;
2215         unsigned long flags;
2216
2217         sdev = ch->sport->sdev;
2218
2219         spin_lock_irqsave(&ch->spinlock, flags);
2220         prev_state = ch->state;
2221         switch (prev_state) {
2222         case CH_CONNECTING:
2223         case CH_LIVE:
2224                 ch->state = CH_DISCONNECTING;
2225                 break;
2226         default:
2227                 break;
2228         }
2229         spin_unlock_irqrestore(&ch->spinlock, flags);
2230
2231         switch (prev_state) {
2232         case CH_CONNECTING:
2233                 ib_send_cm_rej(ch->cm_id, IB_CM_REJ_NO_RESOURCES, NULL, 0,
2234                                NULL, 0);
2235                 /* fall through */
2236         case CH_LIVE:
2237                 if (ib_send_cm_dreq(ch->cm_id, NULL, 0) < 0)
2238                         printk(KERN_ERR "sending CM DREQ failed.\n");
2239                 break;
2240         case CH_DISCONNECTING:
2241                 break;
2242         case CH_DRAINING:
2243         case CH_RELEASING:
2244                 break;
2245         }
2246 }
2247
2248 /**
2249  * srpt_close_ch() - Close an RDMA channel.
2250  */
2251 static void srpt_close_ch(struct srpt_rdma_ch *ch)
2252 {
2253         struct srpt_device *sdev;
2254
2255         sdev = ch->sport->sdev;
2256         spin_lock_irq(&sdev->spinlock);
2257         __srpt_close_ch(ch);
2258         spin_unlock_irq(&sdev->spinlock);
2259 }
2260
2261 /**
2262  * srpt_drain_channel() - Drain a channel by resetting the IB queue pair.
2263  * @cm_id: Pointer to the CM ID of the channel to be drained.
2264  *
2265  * Note: Must be called from inside srpt_cm_handler to avoid a race between
2266  * accessing sdev->spinlock and the call to kfree(sdev) in srpt_remove_one()
2267  * (the caller of srpt_cm_handler holds the cm_id spinlock; srpt_remove_one()
2268  * waits until all target sessions for the associated IB device have been
2269  * unregistered and target session registration involves a call to
2270  * ib_destroy_cm_id(), which locks the cm_id spinlock and hence waits until
2271  * this function has finished).
2272  */
2273 static void srpt_drain_channel(struct ib_cm_id *cm_id)
2274 {
2275         struct srpt_device *sdev;
2276         struct srpt_rdma_ch *ch;
2277         int ret;
2278         bool do_reset = false;
2279
2280         WARN_ON_ONCE(irqs_disabled());
2281
2282         sdev = cm_id->context;
2283         BUG_ON(!sdev);
2284         spin_lock_irq(&sdev->spinlock);
2285         list_for_each_entry(ch, &sdev->rch_list, list) {
2286                 if (ch->cm_id == cm_id) {
2287                         do_reset = srpt_test_and_set_ch_state(ch,
2288                                         CH_CONNECTING, CH_DRAINING) ||
2289                                    srpt_test_and_set_ch_state(ch,
2290                                         CH_LIVE, CH_DRAINING) ||
2291                                    srpt_test_and_set_ch_state(ch,
2292                                         CH_DISCONNECTING, CH_DRAINING);
2293                         break;
2294                 }
2295         }
2296         spin_unlock_irq(&sdev->spinlock);
2297
2298         if (do_reset) {
2299                 ret = srpt_ch_qp_err(ch);
2300                 if (ret < 0)
2301                         printk(KERN_ERR "Setting queue pair in error state"
2302                                " failed: %d\n", ret);
2303         }
2304 }
2305
2306 /**
2307  * srpt_find_channel() - Look up an RDMA channel.
2308  * @cm_id: Pointer to the CM ID of the channel to be looked up.
2309  *
2310  * Return NULL if no matching RDMA channel has been found.
2311  */
2312 static struct srpt_rdma_ch *srpt_find_channel(struct srpt_device *sdev,
2313                                               struct ib_cm_id *cm_id)
2314 {
2315         struct srpt_rdma_ch *ch;
2316         bool found;
2317
2318         WARN_ON_ONCE(irqs_disabled());
2319         BUG_ON(!sdev);
2320
2321         found = false;
2322         spin_lock_irq(&sdev->spinlock);
2323         list_for_each_entry(ch, &sdev->rch_list, list) {
2324                 if (ch->cm_id == cm_id) {
2325                         found = true;
2326                         break;
2327                 }
2328         }
2329         spin_unlock_irq(&sdev->spinlock);
2330
2331         return found ? ch : NULL;
2332 }
2333
2334 /**
2335  * srpt_release_channel() - Release channel resources.
2336  *
2337  * Schedules the actual release because:
2338  * - Calling the ib_destroy_cm_id() call from inside an IB CM callback would
2339  *   trigger a deadlock.
2340  * - It is not safe to call TCM transport_* functions from interrupt context.
2341  */
2342 static void srpt_release_channel(struct srpt_rdma_ch *ch)
2343 {
2344         schedule_work(&ch->release_work);
2345 }
2346
2347 static void srpt_release_channel_work(struct work_struct *w)
2348 {
2349         struct srpt_rdma_ch *ch;
2350         struct srpt_device *sdev;
2351
2352         ch = container_of(w, struct srpt_rdma_ch, release_work);
2353         pr_debug("ch = %p; ch->sess = %p; release_done = %p\n", ch, ch->sess,
2354                  ch->release_done);
2355
2356         sdev = ch->sport->sdev;
2357         BUG_ON(!sdev);
2358
2359         transport_deregister_session_configfs(ch->sess);
2360         transport_deregister_session(ch->sess);
2361         ch->sess = NULL;
2362
2363         srpt_destroy_ch_ib(ch);
2364
2365         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2366                              ch->sport->sdev, ch->rq_size,
2367                              ch->rsp_size, DMA_TO_DEVICE);
2368
2369         spin_lock_irq(&sdev->spinlock);
2370         list_del(&ch->list);
2371         spin_unlock_irq(&sdev->spinlock);
2372
2373         ib_destroy_cm_id(ch->cm_id);
2374
2375         if (ch->release_done)
2376                 complete(ch->release_done);
2377
2378         wake_up(&sdev->ch_releaseQ);
2379
2380         kfree(ch);
2381 }
2382
2383 static struct srpt_node_acl *__srpt_lookup_acl(struct srpt_port *sport,
2384                                                u8 i_port_id[16])
2385 {
2386         struct srpt_node_acl *nacl;
2387
2388         list_for_each_entry(nacl, &sport->port_acl_list, list)
2389                 if (memcmp(nacl->i_port_id, i_port_id,
2390                            sizeof(nacl->i_port_id)) == 0)
2391                         return nacl;
2392
2393         return NULL;
2394 }
2395
2396 static struct srpt_node_acl *srpt_lookup_acl(struct srpt_port *sport,
2397                                              u8 i_port_id[16])
2398 {
2399         struct srpt_node_acl *nacl;
2400
2401         spin_lock_irq(&sport->port_acl_lock);
2402         nacl = __srpt_lookup_acl(sport, i_port_id);
2403         spin_unlock_irq(&sport->port_acl_lock);
2404
2405         return nacl;
2406 }
2407
2408 /**
2409  * srpt_cm_req_recv() - Process the event IB_CM_REQ_RECEIVED.
2410  *
2411  * Ownership of the cm_id is transferred to the target session if this
2412  * functions returns zero. Otherwise the caller remains the owner of cm_id.
2413  */
2414 static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
2415                             struct ib_cm_req_event_param *param,
2416                             void *private_data)
2417 {
2418         struct srpt_device *sdev = cm_id->context;
2419         struct srpt_port *sport = &sdev->port[param->port - 1];
2420         struct srp_login_req *req;
2421         struct srp_login_rsp *rsp;
2422         struct srp_login_rej *rej;
2423         struct ib_cm_rep_param *rep_param;
2424         struct srpt_rdma_ch *ch, *tmp_ch;
2425         struct srpt_node_acl *nacl;
2426         u32 it_iu_len;
2427         int i;
2428         int ret = 0;
2429
2430         WARN_ON_ONCE(irqs_disabled());
2431
2432         if (WARN_ON(!sdev || !private_data))
2433                 return -EINVAL;
2434
2435         req = (struct srp_login_req *)private_data;
2436
2437         it_iu_len = be32_to_cpu(req->req_it_iu_len);
2438
2439         printk(KERN_INFO "Received SRP_LOGIN_REQ with i_port_id 0x%llx:0x%llx,"
2440                " t_port_id 0x%llx:0x%llx and it_iu_len %d on port %d"
2441                " (guid=0x%llx:0x%llx)\n",
2442                be64_to_cpu(*(__be64 *)&req->initiator_port_id[0]),
2443                be64_to_cpu(*(__be64 *)&req->initiator_port_id[8]),
2444                be64_to_cpu(*(__be64 *)&req->target_port_id[0]),
2445                be64_to_cpu(*(__be64 *)&req->target_port_id[8]),
2446                it_iu_len,
2447                param->port,
2448                be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[0]),
2449                be64_to_cpu(*(__be64 *)&sdev->port[param->port - 1].gid.raw[8]));
2450
2451         rsp = kzalloc(sizeof *rsp, GFP_KERNEL);
2452         rej = kzalloc(sizeof *rej, GFP_KERNEL);
2453         rep_param = kzalloc(sizeof *rep_param, GFP_KERNEL);
2454
2455         if (!rsp || !rej || !rep_param) {
2456                 ret = -ENOMEM;
2457                 goto out;
2458         }
2459
2460         if (it_iu_len > srp_max_req_size || it_iu_len < 64) {
2461                 rej->reason = __constant_cpu_to_be32(
2462                                 SRP_LOGIN_REJ_REQ_IT_IU_LENGTH_TOO_LARGE);
2463                 ret = -EINVAL;
2464                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because its"
2465                        " length (%d bytes) is out of range (%d .. %d)\n",
2466                        it_iu_len, 64, srp_max_req_size);
2467                 goto reject;
2468         }
2469
2470         if (!sport->enabled) {
2471                 rej->reason = __constant_cpu_to_be32(
2472                              SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2473                 ret = -EINVAL;
2474                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because the target port"
2475                        " has not yet been enabled\n");
2476                 goto reject;
2477         }
2478
2479         if ((req->req_flags & SRP_MTCH_ACTION) == SRP_MULTICHAN_SINGLE) {
2480                 rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_NO_CHAN;
2481
2482                 spin_lock_irq(&sdev->spinlock);
2483
2484                 list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list) {
2485                         if (!memcmp(ch->i_port_id, req->initiator_port_id, 16)
2486                             && !memcmp(ch->t_port_id, req->target_port_id, 16)
2487                             && param->port == ch->sport->port
2488                             && param->listen_id == ch->sport->sdev->cm_id
2489                             && ch->cm_id) {
2490                                 enum rdma_ch_state ch_state;
2491
2492                                 ch_state = srpt_get_ch_state(ch);
2493                                 if (ch_state != CH_CONNECTING
2494                                     && ch_state != CH_LIVE)
2495                                         continue;
2496
2497                                 /* found an existing channel */
2498                                 pr_debug("Found existing channel %s"
2499                                          " cm_id= %p state= %d\n",
2500                                          ch->sess_name, ch->cm_id, ch_state);
2501
2502                                 __srpt_close_ch(ch);
2503
2504                                 rsp->rsp_flags =
2505                                         SRP_LOGIN_RSP_MULTICHAN_TERMINATED;
2506                         }
2507                 }
2508
2509                 spin_unlock_irq(&sdev->spinlock);
2510
2511         } else
2512                 rsp->rsp_flags = SRP_LOGIN_RSP_MULTICHAN_MAINTAINED;
2513
2514         if (*(__be64 *)req->target_port_id != cpu_to_be64(srpt_service_guid)
2515             || *(__be64 *)(req->target_port_id + 8) !=
2516                cpu_to_be64(srpt_service_guid)) {
2517                 rej->reason = __constant_cpu_to_be32(
2518                                 SRP_LOGIN_REJ_UNABLE_ASSOCIATE_CHANNEL);
2519                 ret = -ENOMEM;
2520                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because it"
2521                        " has an invalid target port identifier.\n");
2522                 goto reject;
2523         }
2524
2525         ch = kzalloc(sizeof *ch, GFP_KERNEL);
2526         if (!ch) {
2527                 rej->reason = __constant_cpu_to_be32(
2528                                         SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2529                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because no memory.\n");
2530                 ret = -ENOMEM;
2531                 goto reject;
2532         }
2533
2534         INIT_WORK(&ch->release_work, srpt_release_channel_work);
2535         memcpy(ch->i_port_id, req->initiator_port_id, 16);
2536         memcpy(ch->t_port_id, req->target_port_id, 16);
2537         ch->sport = &sdev->port[param->port - 1];
2538         ch->cm_id = cm_id;
2539         /*
2540          * Avoid QUEUE_FULL conditions by limiting the number of buffers used
2541          * for the SRP protocol to the command queue size.
2542          */
2543         ch->rq_size = SRPT_RQ_SIZE;
2544         spin_lock_init(&ch->spinlock);
2545         ch->state = CH_CONNECTING;
2546         INIT_LIST_HEAD(&ch->cmd_wait_list);
2547         ch->rsp_size = ch->sport->port_attrib.srp_max_rsp_size;
2548
2549         ch->ioctx_ring = (struct srpt_send_ioctx **)
2550                 srpt_alloc_ioctx_ring(ch->sport->sdev, ch->rq_size,
2551                                       sizeof(*ch->ioctx_ring[0]),
2552                                       ch->rsp_size, DMA_TO_DEVICE);
2553         if (!ch->ioctx_ring)
2554                 goto free_ch;
2555
2556         INIT_LIST_HEAD(&ch->free_list);
2557         for (i = 0; i < ch->rq_size; i++) {
2558                 ch->ioctx_ring[i]->ch = ch;
2559                 list_add_tail(&ch->ioctx_ring[i]->free_list, &ch->free_list);
2560         }
2561
2562         ret = srpt_create_ch_ib(ch);
2563         if (ret) {
2564                 rej->reason = __constant_cpu_to_be32(
2565                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2566                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because creating"
2567                        " a new RDMA channel failed.\n");
2568                 goto free_ring;
2569         }
2570
2571         ret = srpt_ch_qp_rtr(ch, ch->qp);
2572         if (ret) {
2573                 rej->reason = __constant_cpu_to_be32(
2574                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2575                 printk(KERN_ERR "rejected SRP_LOGIN_REQ because enabling"
2576                        " RTR failed (error code = %d)\n", ret);
2577                 goto destroy_ib;
2578         }
2579         /*
2580          * Use the initator port identifier as the session name.
2581          */
2582         snprintf(ch->sess_name, sizeof(ch->sess_name), "0x%016llx%016llx",
2583                         be64_to_cpu(*(__be64 *)ch->i_port_id),
2584                         be64_to_cpu(*(__be64 *)(ch->i_port_id + 8)));
2585
2586         pr_debug("registering session %s\n", ch->sess_name);
2587
2588         nacl = srpt_lookup_acl(sport, ch->i_port_id);
2589         if (!nacl) {
2590                 printk(KERN_INFO "Rejected login because no ACL has been"
2591                        " configured yet for initiator %s.\n", ch->sess_name);
2592                 rej->reason = __constant_cpu_to_be32(
2593                                 SRP_LOGIN_REJ_CHANNEL_LIMIT_REACHED);
2594                 goto destroy_ib;
2595         }
2596
2597         ch->sess = transport_init_session();
2598         if (!ch->sess) {
2599                 rej->reason = __constant_cpu_to_be32(
2600                                 SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
2601                 pr_debug("Failed to create session\n");
2602                 goto deregister_session;
2603         }
2604         ch->sess->se_node_acl = &nacl->nacl;
2605         transport_register_session(&sport->port_tpg_1, &nacl->nacl, ch->sess, ch);
2606
2607         pr_debug("Establish connection sess=%p name=%s cm_id=%p\n", ch->sess,
2608                  ch->sess_name, ch->cm_id);
2609
2610         /* create srp_login_response */
2611         rsp->opcode = SRP_LOGIN_RSP;
2612         rsp->tag = req->tag;
2613         rsp->max_it_iu_len = req->req_it_iu_len;
2614         rsp->max_ti_iu_len = req->req_it_iu_len;
2615         ch->max_ti_iu_len = it_iu_len;
2616         rsp->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2617                                               | SRP_BUF_FORMAT_INDIRECT);
2618         rsp->req_lim_delta = cpu_to_be32(ch->rq_size);
2619         atomic_set(&ch->req_lim, ch->rq_size);
2620         atomic_set(&ch->req_lim_delta, 0);
2621
2622         /* create cm reply */
2623         rep_param->qp_num = ch->qp->qp_num;
2624         rep_param->private_data = (void *)rsp;
2625         rep_param->private_data_len = sizeof *rsp;
2626         rep_param->rnr_retry_count = 7;
2627         rep_param->flow_control = 1;
2628         rep_param->failover_accepted = 0;
2629         rep_param->srq = 1;
2630         rep_param->responder_resources = 4;
2631         rep_param->initiator_depth = 4;
2632
2633         ret = ib_send_cm_rep(cm_id, rep_param);
2634         if (ret) {
2635                 printk(KERN_ERR "sending SRP_LOGIN_REQ response failed"
2636                        " (error code = %d)\n", ret);
2637                 goto release_channel;
2638         }
2639
2640         spin_lock_irq(&sdev->spinlock);
2641         list_add_tail(&ch->list, &sdev->rch_list);
2642         spin_unlock_irq(&sdev->spinlock);
2643
2644         goto out;
2645
2646 release_channel:
2647         srpt_set_ch_state(ch, CH_RELEASING);
2648         transport_deregister_session_configfs(ch->sess);
2649
2650 deregister_session:
2651         transport_deregister_session(ch->sess);
2652         ch->sess = NULL;
2653
2654 destroy_ib:
2655         srpt_destroy_ch_ib(ch);
2656
2657 free_ring:
2658         srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
2659                              ch->sport->sdev, ch->rq_size,
2660                              ch->rsp_size, DMA_TO_DEVICE);
2661 free_ch:
2662         kfree(ch);
2663
2664 reject:
2665         rej->opcode = SRP_LOGIN_REJ;
2666         rej->tag = req->tag;
2667         rej->buf_fmt = __constant_cpu_to_be16(SRP_BUF_FORMAT_DIRECT
2668                                               | SRP_BUF_FORMAT_INDIRECT);
2669
2670         ib_send_cm_rej(cm_id, IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
2671                              (void *)rej, sizeof *rej);
2672
2673 out:
2674         kfree(rep_param);
2675         kfree(rsp);
2676         kfree(rej);
2677
2678         return ret;
2679 }
2680
2681 static void srpt_cm_rej_recv(struct ib_cm_id *cm_id)
2682 {
2683         printk(KERN_INFO "Received IB REJ for cm_id %p.\n", cm_id);
2684         srpt_drain_channel(cm_id);
2685 }
2686
2687 /**
2688  * srpt_cm_rtu_recv() - Process an IB_CM_RTU_RECEIVED or USER_ESTABLISHED event.
2689  *
2690  * An IB_CM_RTU_RECEIVED message indicates that the connection is established
2691  * and that the recipient may begin transmitting (RTU = ready to use).
2692  */
2693 static void srpt_cm_rtu_recv(struct ib_cm_id *cm_id)
2694 {
2695         struct srpt_rdma_ch *ch;
2696         int ret;
2697
2698         ch = srpt_find_channel(cm_id->context, cm_id);
2699         BUG_ON(!ch);
2700
2701         if (srpt_test_and_set_ch_state(ch, CH_CONNECTING, CH_LIVE)) {
2702                 struct srpt_recv_ioctx *ioctx, *ioctx_tmp;
2703
2704                 ret = srpt_ch_qp_rts(ch, ch->qp);
2705
2706                 list_for_each_entry_safe(ioctx, ioctx_tmp, &ch->cmd_wait_list,
2707                                          wait_list) {
2708                         list_del(&ioctx->wait_list);
2709                         srpt_handle_new_iu(ch, ioctx, NULL);
2710                 }
2711                 if (ret)
2712                         srpt_close_ch(ch);
2713         }
2714 }
2715
2716 static void srpt_cm_timewait_exit(struct ib_cm_id *cm_id)
2717 {
2718         printk(KERN_INFO "Received IB TimeWait exit for cm_id %p.\n", cm_id);
2719         srpt_drain_channel(cm_id);
2720 }
2721
2722 static void srpt_cm_rep_error(struct ib_cm_id *cm_id)
2723 {
2724         printk(KERN_INFO "Received IB REP error for cm_id %p.\n", cm_id);
2725         srpt_drain_channel(cm_id);
2726 }
2727
2728 /**
2729  * srpt_cm_dreq_recv() - Process reception of a DREQ message.
2730  */
2731 static void srpt_cm_dreq_recv(struct ib_cm_id *cm_id)
2732 {
2733         struct srpt_rdma_ch *ch;
2734         unsigned long flags;
2735         bool send_drep = false;
2736
2737         ch = srpt_find_channel(cm_id->context, cm_id);
2738         BUG_ON(!ch);
2739
2740         pr_debug("cm_id= %p ch->state= %d\n", cm_id, srpt_get_ch_state(ch));
2741
2742         spin_lock_irqsave(&ch->spinlock, flags);
2743         switch (ch->state) {
2744         case CH_CONNECTING:
2745         case CH_LIVE:
2746                 send_drep = true;
2747                 ch->state = CH_DISCONNECTING;
2748                 break;
2749         case CH_DISCONNECTING:
2750         case CH_DRAINING:
2751         case CH_RELEASING:
2752                 WARN(true, "unexpected channel state %d\n", ch->state);
2753                 break;
2754         }
2755         spin_unlock_irqrestore(&ch->spinlock, flags);
2756
2757         if (send_drep) {
2758                 if (ib_send_cm_drep(ch->cm_id, NULL, 0) < 0)
2759                         printk(KERN_ERR "Sending IB DREP failed.\n");
2760                 printk(KERN_INFO "Received DREQ and sent DREP for session %s.\n",
2761                        ch->sess_name);
2762         }
2763 }
2764
2765 /**
2766  * srpt_cm_drep_recv() - Process reception of a DREP message.
2767  */
2768 static void srpt_cm_drep_recv(struct ib_cm_id *cm_id)
2769 {
2770         printk(KERN_INFO "Received InfiniBand DREP message for cm_id %p.\n",
2771                cm_id);
2772         srpt_drain_channel(cm_id);
2773 }
2774
2775 /**
2776  * srpt_cm_handler() - IB connection manager callback function.
2777  *
2778  * A non-zero return value will cause the caller destroy the CM ID.
2779  *
2780  * Note: srpt_cm_handler() must only return a non-zero value when transferring
2781  * ownership of the cm_id to a channel by srpt_cm_req_recv() failed. Returning
2782  * a non-zero value in any other case will trigger a race with the
2783  * ib_destroy_cm_id() call in srpt_release_channel().
2784  */
2785 static int srpt_cm_handler(struct ib_cm_id *cm_id, struct ib_cm_event *event)
2786 {
2787         int ret;
2788
2789         ret = 0;
2790         switch (event->event) {
2791         case IB_CM_REQ_RECEIVED:
2792                 ret = srpt_cm_req_recv(cm_id, &event->param.req_rcvd,
2793                                        event->private_data);
2794                 break;
2795         case IB_CM_REJ_RECEIVED:
2796                 srpt_cm_rej_recv(cm_id);
2797                 break;
2798         case IB_CM_RTU_RECEIVED:
2799         case IB_CM_USER_ESTABLISHED:
2800                 srpt_cm_rtu_recv(cm_id);
2801                 break;
2802         case IB_CM_DREQ_RECEIVED:
2803                 srpt_cm_dreq_recv(cm_id);
2804                 break;
2805         case IB_CM_DREP_RECEIVED:
2806                 srpt_cm_drep_recv(cm_id);
2807                 break;
2808         case IB_CM_TIMEWAIT_EXIT:
2809                 srpt_cm_timewait_exit(cm_id);
2810                 break;
2811         case IB_CM_REP_ERROR:
2812                 srpt_cm_rep_error(cm_id);
2813                 break;
2814         case IB_CM_DREQ_ERROR:
2815                 printk(KERN_INFO "Received IB DREQ ERROR event.\n");
2816                 break;
2817         case IB_CM_MRA_RECEIVED:
2818                 printk(KERN_INFO "Received IB MRA event\n");
2819                 break;
2820         default:
2821                 printk(KERN_ERR "received unrecognized IB CM event %d\n",
2822                        event->event);
2823                 break;
2824         }
2825
2826         return ret;
2827 }
2828
2829 /**
2830  * srpt_perform_rdmas() - Perform IB RDMA.
2831  *
2832  * Returns zero upon success or a negative number upon failure.
2833  */
2834 static int srpt_perform_rdmas(struct srpt_rdma_ch *ch,
2835                               struct srpt_send_ioctx *ioctx)
2836 {
2837         struct ib_send_wr wr;
2838         struct ib_send_wr *bad_wr;
2839         struct rdma_iu *riu;
2840         int i;
2841         int ret;
2842         int sq_wr_avail;
2843         enum dma_data_direction dir;
2844         const int n_rdma = ioctx->n_rdma;
2845
2846         dir = ioctx->cmd.data_direction;
2847         if (dir == DMA_TO_DEVICE) {
2848                 /* write */
2849                 ret = -ENOMEM;
2850                 sq_wr_avail = atomic_sub_return(n_rdma, &ch->sq_wr_avail);
2851                 if (sq_wr_avail < 0) {
2852                         printk(KERN_WARNING "IB send queue full (needed %d)\n",
2853                                n_rdma);
2854                         goto out;
2855                 }
2856         }
2857
2858         ioctx->rdma_aborted = false;
2859         ret = 0;
2860         riu = ioctx->rdma_ius;
2861         memset(&wr, 0, sizeof wr);
2862
2863         for (i = 0; i < n_rdma; ++i, ++riu) {
2864                 if (dir == DMA_FROM_DEVICE) {
2865                         wr.opcode = IB_WR_RDMA_WRITE;
2866                         wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2867                                                 SRPT_RDMA_WRITE_LAST :
2868                                                 SRPT_RDMA_MID,
2869                                                 ioctx->ioctx.index);
2870                 } else {
2871                         wr.opcode = IB_WR_RDMA_READ;
2872                         wr.wr_id = encode_wr_id(i == n_rdma - 1 ?
2873                                                 SRPT_RDMA_READ_LAST :
2874                                                 SRPT_RDMA_MID,
2875                                                 ioctx->ioctx.index);
2876                 }
2877                 wr.next = NULL;
2878                 wr.wr.rdma.remote_addr = riu->raddr;
2879                 wr.wr.rdma.rkey = riu->rkey;
2880                 wr.num_sge = riu->sge_cnt;
2881                 wr.sg_list = riu->sge;
2882
2883                 /* only get completion event for the last rdma write */
2884                 if (i == (n_rdma - 1) && dir == DMA_TO_DEVICE)
2885                         wr.send_flags = IB_SEND_SIGNALED;
2886
2887                 ret = ib_post_send(ch->qp, &wr, &bad_wr);
2888                 if (ret)
2889                         break;
2890         }
2891
2892         if (ret)
2893                 printk(KERN_ERR "%s[%d]: ib_post_send() returned %d for %d/%d",
2894                                  __func__, __LINE__, ret, i, n_rdma);
2895         if (ret && i > 0) {
2896                 wr.num_sge = 0;
2897                 wr.wr_id = encode_wr_id(SRPT_RDMA_ABORT, ioctx->ioctx.index);
2898                 wr.send_flags = IB_SEND_SIGNALED;
2899                 while (ch->state == CH_LIVE &&
2900                         ib_post_send(ch->qp, &wr, &bad_wr) != 0) {
2901                         printk(KERN_INFO "Trying to abort failed RDMA transfer [%d]",
2902                                 ioctx->ioctx.index);
2903                         msleep(1000);
2904                 }
2905                 while (ch->state != CH_RELEASING && !ioctx->rdma_aborted) {
2906                         printk(KERN_INFO "Waiting until RDMA abort finished [%d]",
2907                                 ioctx->ioctx.index);
2908                         msleep(1000);
2909                 }
2910         }
2911 out:
2912         if (unlikely(dir == DMA_TO_DEVICE && ret < 0))
2913                 atomic_add(n_rdma, &ch->sq_wr_avail);
2914         return ret;
2915 }
2916
2917 /**
2918  * srpt_xfer_data() - Start data transfer from initiator to target.
2919  */
2920 static int srpt_xfer_data(struct srpt_rdma_ch *ch,
2921                           struct srpt_send_ioctx *ioctx)
2922 {
2923         int ret;
2924
2925         ret = srpt_map_sg_to_ib_sge(ch, ioctx);
2926         if (ret) {
2927                 printk(KERN_ERR "%s[%d] ret=%d\n", __func__, __LINE__, ret);
2928                 goto out;
2929         }
2930
2931         ret = srpt_perform_rdmas(ch, ioctx);
2932         if (ret) {
2933                 if (ret == -EAGAIN || ret == -ENOMEM)
2934                         printk(KERN_INFO "%s[%d] queue full -- ret=%d\n",
2935                                    __func__, __LINE__, ret);
2936                 else
2937                         printk(KERN_ERR "%s[%d] fatal error -- ret=%d\n",
2938                                __func__, __LINE__, ret);
2939                 goto out_unmap;
2940         }
2941
2942 out:
2943         return ret;
2944 out_unmap:
2945         srpt_unmap_sg_to_ib_sge(ch, ioctx);
2946         goto out;
2947 }
2948
2949 static int srpt_write_pending_status(struct se_cmd *se_cmd)
2950 {
2951         struct srpt_send_ioctx *ioctx;
2952
2953         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2954         return srpt_get_cmd_state(ioctx) == SRPT_STATE_NEED_DATA;
2955 }
2956
2957 /*
2958  * srpt_write_pending() - Start data transfer from initiator to target (write).
2959  */
2960 static int srpt_write_pending(struct se_cmd *se_cmd)
2961 {
2962         struct srpt_rdma_ch *ch;
2963         struct srpt_send_ioctx *ioctx;
2964         enum srpt_command_state new_state;
2965         enum rdma_ch_state ch_state;
2966         int ret;
2967
2968         ioctx = container_of(se_cmd, struct srpt_send_ioctx, cmd);
2969
2970         new_state = srpt_set_cmd_state(ioctx, SRPT_STATE_NEED_DATA);
2971         WARN_ON(new_state == SRPT_STATE_DONE);
2972
2973         ch = ioctx->ch;
2974         BUG_ON(!ch);
2975
2976         ch_state = srpt_get_ch_state(ch);
2977         switch (ch_state) {
2978         case CH_CONNECTING:
2979                 WARN(true, "unexpected channel state %d\n", ch_state);
2980                 ret = -EINVAL;
2981                 goto out;
2982         case CH_LIVE:
2983                 break;
2984         case CH_DISCONNECTING:
2985         case CH_DRAINING:
2986         case CH_RELEASING:
2987                 pr_debug("cmd with tag %lld: channel disconnecting\n",
2988                          ioctx->tag);
2989                 srpt_set_cmd_state(ioctx, SRPT_STATE_DATA_IN);
2990                 ret = -EINVAL;
2991                 goto out;
2992         }
2993         ret = srpt_xfer_data(ch, ioctx);
2994
2995 out:
2996         return ret;
2997 }
2998
2999 static u8 tcm_to_srp_tsk_mgmt_status(const int tcm_mgmt_status)
3000 {
3001         switch (tcm_mgmt_status) {
3002         case TMR_FUNCTION_COMPLETE:
3003                 return SRP_TSK_MGMT_SUCCESS;
3004         case TMR_FUNCTION_REJECTED:
3005                 return SRP_TSK_MGMT_FUNC_NOT_SUPP;
3006         }
3007         return SRP_TSK_MGMT_FAILED;
3008 }
3009
3010 /**
3011  * srpt_queue_response() - Transmits the response to a SCSI command.
3012  *
3013  * Callback function called by the TCM core. Must not block since it can be
3014  * invoked on the context of the IB completion handler.
3015  */
3016 static int srpt_queue_response(struct se_cmd *cmd)
3017 {
3018         struct srpt_rdma_ch *ch;
3019         struct srpt_send_ioctx *ioctx;
3020         enum srpt_command_state state;
3021         unsigned long flags;
3022         int ret;
3023         enum dma_data_direction dir;
3024         int resp_len;
3025         u8 srp_tm_status;
3026
3027         ret = 0;
3028
3029         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3030         ch = ioctx->ch;
3031         BUG_ON(!ch);
3032
3033         spin_lock_irqsave(&ioctx->spinlock, flags);
3034         state = ioctx->state;
3035         switch (state) {
3036         case SRPT_STATE_NEW:
3037         case SRPT_STATE_DATA_IN:
3038                 ioctx->state = SRPT_STATE_CMD_RSP_SENT;
3039                 break;
3040         case SRPT_STATE_MGMT:
3041                 ioctx->state = SRPT_STATE_MGMT_RSP_SENT;
3042                 break;
3043         default:
3044                 WARN(true, "ch %p; cmd %d: unexpected command state %d\n",
3045                         ch, ioctx->ioctx.index, ioctx->state);
3046                 break;
3047         }
3048         spin_unlock_irqrestore(&ioctx->spinlock, flags);
3049
3050         if (unlikely(transport_check_aborted_status(&ioctx->cmd, false)
3051                      || WARN_ON_ONCE(state == SRPT_STATE_CMD_RSP_SENT))) {
3052                 atomic_inc(&ch->req_lim_delta);
3053                 srpt_abort_cmd(ioctx);
3054                 goto out;
3055         }
3056
3057         dir = ioctx->cmd.data_direction;
3058
3059         /* For read commands, transfer the data to the initiator. */
3060         if (dir == DMA_FROM_DEVICE && ioctx->cmd.data_length &&
3061             !ioctx->queue_status_only) {
3062                 ret = srpt_xfer_data(ch, ioctx);
3063                 if (ret) {
3064                         printk(KERN_ERR "xfer_data failed for tag %llu\n",
3065                                ioctx->tag);
3066                         goto out;
3067                 }
3068         }
3069
3070         if (state != SRPT_STATE_MGMT)
3071                 resp_len = srpt_build_cmd_rsp(ch, ioctx, ioctx->tag,
3072                                               cmd->scsi_status);
3073         else {
3074                 srp_tm_status
3075                         = tcm_to_srp_tsk_mgmt_status(cmd->se_tmr_req->response);
3076                 resp_len = srpt_build_tskmgmt_rsp(ch, ioctx, srp_tm_status,
3077                                                  ioctx->tag);
3078         }
3079         ret = srpt_post_send(ch, ioctx, resp_len);
3080         if (ret) {
3081                 printk(KERN_ERR "sending cmd response failed for tag %llu\n",
3082                        ioctx->tag);
3083                 srpt_unmap_sg_to_ib_sge(ch, ioctx);
3084                 srpt_set_cmd_state(ioctx, SRPT_STATE_DONE);
3085                 kref_put(&ioctx->kref, srpt_put_send_ioctx_kref);
3086         }
3087
3088 out:
3089         return ret;
3090 }
3091
3092 static int srpt_queue_status(struct se_cmd *cmd)
3093 {
3094         struct srpt_send_ioctx *ioctx;
3095
3096         ioctx = container_of(cmd, struct srpt_send_ioctx, cmd);
3097         BUG_ON(ioctx->sense_data != cmd->sense_buffer);
3098         if (cmd->se_cmd_flags &
3099             (SCF_TRANSPORT_TASK_SENSE | SCF_EMULATED_TASK_SENSE))
3100                 WARN_ON(cmd->scsi_status != SAM_STAT_CHECK_CONDITION);
3101         ioctx->queue_status_only = true;
3102         return srpt_queue_response(cmd);
3103 }
3104
3105 static void srpt_refresh_port_work(struct work_struct *work)
3106 {
3107         struct srpt_port *sport = container_of(work, struct srpt_port, work);
3108
3109         srpt_refresh_port(sport);
3110 }
3111
3112 static int srpt_ch_list_empty(struct srpt_device *sdev)
3113 {
3114         int res;
3115
3116         spin_lock_irq(&sdev->spinlock);
3117         res = list_empty(&sdev->rch_list);
3118         spin_unlock_irq(&sdev->spinlock);
3119
3120         return res;
3121 }
3122
3123 /**
3124  * srpt_release_sdev() - Free the channel resources associated with a target.
3125  */
3126 static int srpt_release_sdev(struct srpt_device *sdev)
3127 {
3128         struct srpt_rdma_ch *ch, *tmp_ch;
3129         int res;
3130
3131         WARN_ON_ONCE(irqs_disabled());
3132
3133         BUG_ON(!sdev);
3134
3135         spin_lock_irq(&sdev->spinlock);
3136         list_for_each_entry_safe(ch, tmp_ch, &sdev->rch_list, list)
3137                 __srpt_close_ch(ch);
3138         spin_unlock_irq(&sdev->spinlock);
3139
3140         res = wait_event_interruptible(sdev->ch_releaseQ,
3141                                        srpt_ch_list_empty(sdev));
3142         if (res)
3143                 printk(KERN_ERR "%s: interrupted.\n", __func__);
3144
3145         return 0;
3146 }
3147
3148 static struct srpt_port *__srpt_lookup_port(const char *name)
3149 {
3150         struct ib_device *dev;
3151         struct srpt_device *sdev;
3152         struct srpt_port *sport;
3153         int i;
3154
3155         list_for_each_entry(sdev, &srpt_dev_list, list) {
3156                 dev = sdev->device;
3157                 if (!dev)
3158                         continue;
3159
3160                 for (i = 0; i < dev->phys_port_cnt; i++) {
3161                         sport = &sdev->port[i];
3162
3163                         if (!strcmp(sport->port_guid, name))
3164                                 return sport;
3165                 }
3166         }
3167
3168         return NULL;
3169 }
3170
3171 static struct srpt_port *srpt_lookup_port(const char *name)
3172 {
3173         struct srpt_port *sport;
3174
3175         spin_lock(&srpt_dev_lock);
3176         sport = __srpt_lookup_port(name);
3177         spin_unlock(&srpt_dev_lock);
3178
3179         return sport;
3180 }
3181
3182 /**
3183  * srpt_add_one() - Infiniband device addition callback function.
3184  */
3185 static void srpt_add_one(struct ib_device *device)
3186 {
3187         struct srpt_device *sdev;
3188         struct srpt_port *sport;
3189         struct ib_srq_init_attr srq_attr;
3190         int i;
3191
3192         pr_debug("device = %p, device->dma_ops = %p\n", device,
3193                  device->dma_ops);
3194
3195         sdev = kzalloc(sizeof *sdev, GFP_KERNEL);
3196         if (!sdev)
3197                 goto err;
3198
3199         sdev->device = device;
3200         INIT_LIST_HEAD(&sdev->rch_list);
3201         init_waitqueue_head(&sdev->ch_releaseQ);
3202         spin_lock_init(&sdev->spinlock);
3203
3204         if (ib_query_device(device, &sdev->dev_attr))
3205                 goto free_dev;
3206
3207         sdev->pd = ib_alloc_pd(device);
3208         if (IS_ERR(sdev->pd))
3209                 goto free_dev;
3210
3211         sdev->mr = ib_get_dma_mr(sdev->pd, IB_ACCESS_LOCAL_WRITE);
3212         if (IS_ERR(sdev->mr))
3213                 goto err_pd;
3214
3215         sdev->srq_size = min(srpt_srq_size, sdev->dev_attr.max_srq_wr);
3216
3217         srq_attr.event_handler = srpt_srq_event;
3218         srq_attr.srq_context = (void *)sdev;
3219         srq_attr.attr.max_wr = sdev->srq_size;
3220         srq_attr.attr.max_sge = 1;
3221         srq_attr.attr.srq_limit = 0;
3222
3223         sdev->srq = ib_create_srq(sdev->pd, &srq_attr);
3224         if (IS_ERR(sdev->srq))
3225                 goto err_mr;
3226
3227         pr_debug("%s: create SRQ #wr= %d max_allow=%d dev= %s\n",
3228                  __func__, sdev->srq_size, sdev->dev_attr.max_srq_wr,
3229                  device->name);
3230