xref: /linux/drivers/infiniband/ulp/iser/iser_initiator.c (revision eed4edda910fe34dfae8c6bfbcf57f4593a54295)
1 /*
2  * Copyright (c) 2004, 2005, 2006 Voltaire, Inc. All rights reserved.
3  * Copyright (c) 2013-2014 Mellanox Technologies. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *	- Redistributions of source code must retain the above
16  *	  copyright notice, this list of conditions and the following
17  *	  disclaimer.
18  *
19  *	- Redistributions in binary form must reproduce the above
20  *	  copyright notice, this list of conditions and the following
21  *	  disclaimer in the documentation and/or other materials
22  *	  provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 #include <linux/kernel.h>
34 #include <linux/slab.h>
35 #include <linux/mm.h>
36 #include <linux/scatterlist.h>
37 #include <linux/kfifo.h>
38 #include <scsi/scsi_cmnd.h>
39 #include <scsi/scsi_host.h>
40 
41 #include "iscsi_iser.h"
42 
43 /* Register user buffer memory and initialize passive rdma
44  *  dto descriptor. Data size is stored in
45  *  task->data[ISER_DIR_IN].data_len, Protection size
46  *  os stored in task->prot[ISER_DIR_IN].data_len
47  */
48 static int iser_prepare_read_cmd(struct iscsi_task *task)
49 
50 {
51 	struct iscsi_iser_task *iser_task = task->dd_data;
52 	struct iser_mem_reg *mem_reg;
53 	int err;
54 	struct iser_ctrl *hdr = &iser_task->desc.iser_header;
55 
56 	err = iser_dma_map_task_data(iser_task,
57 				     ISER_DIR_IN,
58 				     DMA_FROM_DEVICE);
59 	if (err)
60 		return err;
61 
62 	err = iser_reg_mem_fastreg(iser_task, ISER_DIR_IN, false);
63 	if (err) {
64 		iser_err("Failed to set up Data-IN RDMA\n");
65 		goto out_err;
66 	}
67 	mem_reg = &iser_task->rdma_reg[ISER_DIR_IN];
68 
69 	hdr->flags    |= ISER_RSV;
70 	hdr->read_stag = cpu_to_be32(mem_reg->rkey);
71 	hdr->read_va   = cpu_to_be64(mem_reg->sge.addr);
72 
73 	iser_dbg("Cmd itt:%d READ tags RKEY:%#.4X VA:%#llX\n",
74 		 task->itt, mem_reg->rkey,
75 		 (unsigned long long)mem_reg->sge.addr);
76 
77 	return 0;
78 
79 out_err:
80 	iser_dma_unmap_task_data(iser_task, ISER_DIR_IN, DMA_FROM_DEVICE);
81 	return err;
82 }
83 
84 /* Register user buffer memory and initialize passive rdma
85  *  dto descriptor. Data size is stored in
86  *  task->data[ISER_DIR_OUT].data_len, Protection size
87  *  is stored at task->prot[ISER_DIR_OUT].data_len
88  */
89 static int iser_prepare_write_cmd(struct iscsi_task *task, unsigned int imm_sz,
90 				  unsigned int unsol_sz, unsigned int edtl)
91 {
92 	struct iscsi_iser_task *iser_task = task->dd_data;
93 	struct iser_mem_reg *mem_reg;
94 	int err;
95 	struct iser_ctrl *hdr = &iser_task->desc.iser_header;
96 	struct iser_data_buf *buf_out = &iser_task->data[ISER_DIR_OUT];
97 	struct ib_sge *tx_dsg = &iser_task->desc.tx_sg[1];
98 
99 	err = iser_dma_map_task_data(iser_task,
100 				     ISER_DIR_OUT,
101 				     DMA_TO_DEVICE);
102 	if (err)
103 		return err;
104 
105 	err = iser_reg_mem_fastreg(iser_task, ISER_DIR_OUT,
106 				   buf_out->data_len == imm_sz);
107 	if (err) {
108 		iser_err("Failed to register write cmd RDMA mem\n");
109 		goto out_err;
110 	}
111 
112 	mem_reg = &iser_task->rdma_reg[ISER_DIR_OUT];
113 
114 	if (unsol_sz < edtl) {
115 		hdr->flags     |= ISER_WSV;
116 		if (buf_out->data_len > imm_sz) {
117 			hdr->write_stag = cpu_to_be32(mem_reg->rkey);
118 			hdr->write_va = cpu_to_be64(mem_reg->sge.addr + unsol_sz);
119 		}
120 
121 		iser_dbg("Cmd itt:%d, WRITE tags, RKEY:%#.4X VA:%#llX + unsol:%d\n",
122 			 task->itt, mem_reg->rkey,
123 			 (unsigned long long)mem_reg->sge.addr, unsol_sz);
124 	}
125 
126 	if (imm_sz > 0) {
127 		iser_dbg("Cmd itt:%d, WRITE, adding imm.data sz: %d\n",
128 			 task->itt, imm_sz);
129 		tx_dsg->addr = mem_reg->sge.addr;
130 		tx_dsg->length = imm_sz;
131 		tx_dsg->lkey = mem_reg->sge.lkey;
132 		iser_task->desc.num_sge = 2;
133 	}
134 
135 	return 0;
136 
137 out_err:
138 	iser_dma_unmap_task_data(iser_task, ISER_DIR_OUT, DMA_TO_DEVICE);
139 	return err;
140 }
141 
142 /* creates a new tx descriptor and adds header regd buffer */
143 static void iser_create_send_desc(struct iser_conn *iser_conn,
144 		struct iser_tx_desc *tx_desc, enum iser_desc_type type,
145 		void (*done)(struct ib_cq *cq, struct ib_wc *wc))
146 {
147 	struct iser_device *device = iser_conn->ib_conn.device;
148 
149 	tx_desc->type = type;
150 	tx_desc->cqe.done = done;
151 
152 	ib_dma_sync_single_for_cpu(device->ib_device,
153 		tx_desc->dma_addr, ISER_HEADERS_LEN, DMA_TO_DEVICE);
154 
155 	memset(&tx_desc->iser_header, 0, sizeof(struct iser_ctrl));
156 	tx_desc->iser_header.flags = ISER_VER;
157 	tx_desc->num_sge = 1;
158 }
159 
160 static void iser_free_login_buf(struct iser_conn *iser_conn)
161 {
162 	struct iser_device *device = iser_conn->ib_conn.device;
163 	struct iser_login_desc *desc = &iser_conn->login_desc;
164 
165 	if (!desc->req)
166 		return;
167 
168 	ib_dma_unmap_single(device->ib_device, desc->req_dma,
169 			    ISCSI_DEF_MAX_RECV_SEG_LEN, DMA_TO_DEVICE);
170 
171 	ib_dma_unmap_single(device->ib_device, desc->rsp_dma,
172 			    ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
173 
174 	kfree(desc->req);
175 	kfree(desc->rsp);
176 
177 	/* make sure we never redo any unmapping */
178 	desc->req = NULL;
179 	desc->rsp = NULL;
180 }
181 
182 static int iser_alloc_login_buf(struct iser_conn *iser_conn)
183 {
184 	struct iser_device *device = iser_conn->ib_conn.device;
185 	struct iser_login_desc *desc = &iser_conn->login_desc;
186 
187 	desc->req = kmalloc(ISCSI_DEF_MAX_RECV_SEG_LEN, GFP_KERNEL);
188 	if (!desc->req)
189 		return -ENOMEM;
190 
191 	desc->req_dma = ib_dma_map_single(device->ib_device, desc->req,
192 					  ISCSI_DEF_MAX_RECV_SEG_LEN,
193 					  DMA_TO_DEVICE);
194 	if (ib_dma_mapping_error(device->ib_device,
195 				desc->req_dma))
196 		goto free_req;
197 
198 	desc->rsp = kmalloc(ISER_RX_LOGIN_SIZE, GFP_KERNEL);
199 	if (!desc->rsp)
200 		goto unmap_req;
201 
202 	desc->rsp_dma = ib_dma_map_single(device->ib_device, desc->rsp,
203 					   ISER_RX_LOGIN_SIZE,
204 					   DMA_FROM_DEVICE);
205 	if (ib_dma_mapping_error(device->ib_device,
206 				desc->rsp_dma))
207 		goto free_rsp;
208 
209 	return 0;
210 
211 free_rsp:
212 	kfree(desc->rsp);
213 unmap_req:
214 	ib_dma_unmap_single(device->ib_device, desc->req_dma,
215 			    ISCSI_DEF_MAX_RECV_SEG_LEN,
216 			    DMA_TO_DEVICE);
217 free_req:
218 	kfree(desc->req);
219 
220 	return -ENOMEM;
221 }
222 
223 int iser_alloc_rx_descriptors(struct iser_conn *iser_conn,
224 			      struct iscsi_session *session)
225 {
226 	int i, j;
227 	u64 dma_addr;
228 	struct iser_rx_desc *rx_desc;
229 	struct ib_sge       *rx_sg;
230 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
231 	struct iser_device *device = ib_conn->device;
232 
233 	iser_conn->qp_max_recv_dtos = session->cmds_max;
234 
235 	if (iser_alloc_fastreg_pool(ib_conn, session->scsi_cmds_max,
236 				    iser_conn->pages_per_mr))
237 		goto create_rdma_reg_res_failed;
238 
239 	if (iser_alloc_login_buf(iser_conn))
240 		goto alloc_login_buf_fail;
241 
242 	iser_conn->num_rx_descs = session->cmds_max;
243 	iser_conn->rx_descs = kmalloc_array(iser_conn->num_rx_descs,
244 					    sizeof(struct iser_rx_desc),
245 					    GFP_KERNEL);
246 	if (!iser_conn->rx_descs)
247 		goto rx_desc_alloc_fail;
248 
249 	rx_desc = iser_conn->rx_descs;
250 
251 	for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)  {
252 		dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
253 					ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
254 		if (ib_dma_mapping_error(device->ib_device, dma_addr))
255 			goto rx_desc_dma_map_failed;
256 
257 		rx_desc->dma_addr = dma_addr;
258 		rx_desc->cqe.done = iser_task_rsp;
259 		rx_sg = &rx_desc->rx_sg;
260 		rx_sg->addr = rx_desc->dma_addr;
261 		rx_sg->length = ISER_RX_PAYLOAD_SIZE;
262 		rx_sg->lkey = device->pd->local_dma_lkey;
263 	}
264 
265 	return 0;
266 
267 rx_desc_dma_map_failed:
268 	rx_desc = iser_conn->rx_descs;
269 	for (j = 0; j < i; j++, rx_desc++)
270 		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
271 				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
272 	kfree(iser_conn->rx_descs);
273 	iser_conn->rx_descs = NULL;
274 rx_desc_alloc_fail:
275 	iser_free_login_buf(iser_conn);
276 alloc_login_buf_fail:
277 	iser_free_fastreg_pool(ib_conn);
278 create_rdma_reg_res_failed:
279 	iser_err("failed allocating rx descriptors / data buffers\n");
280 	return -ENOMEM;
281 }
282 
283 void iser_free_rx_descriptors(struct iser_conn *iser_conn)
284 {
285 	int i;
286 	struct iser_rx_desc *rx_desc;
287 	struct ib_conn *ib_conn = &iser_conn->ib_conn;
288 	struct iser_device *device = ib_conn->device;
289 
290 	iser_free_fastreg_pool(ib_conn);
291 
292 	rx_desc = iser_conn->rx_descs;
293 	for (i = 0; i < iser_conn->qp_max_recv_dtos; i++, rx_desc++)
294 		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
295 				    ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
296 	kfree(iser_conn->rx_descs);
297 	/* make sure we never redo any unmapping */
298 	iser_conn->rx_descs = NULL;
299 
300 	iser_free_login_buf(iser_conn);
301 }
302 
303 static int iser_post_rx_bufs(struct iscsi_conn *conn, struct iscsi_hdr *req)
304 {
305 	struct iser_conn *iser_conn = conn->dd_data;
306 	struct iscsi_session *session = conn->session;
307 	int err = 0;
308 	int i;
309 
310 	iser_dbg("req op %x flags %x\n", req->opcode, req->flags);
311 	/* check if this is the last login - going to full feature phase */
312 	if ((req->flags & ISCSI_FULL_FEATURE_PHASE) != ISCSI_FULL_FEATURE_PHASE)
313 		goto out;
314 
315 	if (session->discovery_sess) {
316 		iser_info("Discovery session, re-using login RX buffer\n");
317 		goto out;
318 	}
319 
320 	iser_info("Normal session, posting batch of RX %d buffers\n",
321 		  iser_conn->qp_max_recv_dtos - 1);
322 
323 	/*
324 	 * Initial post receive buffers.
325 	 * There is one already posted recv buffer (for the last login
326 	 * response). Therefore, the first recv buffer is skipped here.
327 	 */
328 	for (i = 1; i < iser_conn->qp_max_recv_dtos; i++) {
329 		err = iser_post_recvm(iser_conn, &iser_conn->rx_descs[i]);
330 		if (err)
331 			goto out;
332 	}
333 out:
334 	return err;
335 }
336 
337 /**
338  * iser_send_command - send command PDU
339  * @conn: link to matching iscsi connection
340  * @task: SCSI command task
341  */
342 int iser_send_command(struct iscsi_conn *conn, struct iscsi_task *task)
343 {
344 	struct iser_conn *iser_conn = conn->dd_data;
345 	struct iscsi_iser_task *iser_task = task->dd_data;
346 	unsigned long edtl;
347 	int err;
348 	struct iser_data_buf *data_buf, *prot_buf;
349 	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)task->hdr;
350 	struct scsi_cmnd *sc  =  task->sc;
351 	struct iser_tx_desc *tx_desc = &iser_task->desc;
352 
353 	edtl = ntohl(hdr->data_length);
354 
355 	/* build the tx desc regd header and add it to the tx desc dto */
356 	iser_create_send_desc(iser_conn, tx_desc, ISCSI_TX_SCSI_COMMAND,
357 			      iser_cmd_comp);
358 
359 	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
360 		data_buf = &iser_task->data[ISER_DIR_IN];
361 		prot_buf = &iser_task->prot[ISER_DIR_IN];
362 	} else {
363 		data_buf = &iser_task->data[ISER_DIR_OUT];
364 		prot_buf = &iser_task->prot[ISER_DIR_OUT];
365 	}
366 
367 	if (scsi_sg_count(sc)) { /* using a scatter list */
368 		data_buf->sg = scsi_sglist(sc);
369 		data_buf->size = scsi_sg_count(sc);
370 	}
371 	data_buf->data_len = scsi_bufflen(sc);
372 
373 	if (scsi_prot_sg_count(sc)) {
374 		prot_buf->sg  = scsi_prot_sglist(sc);
375 		prot_buf->size = scsi_prot_sg_count(sc);
376 		prot_buf->data_len = (data_buf->data_len >>
377 				     ilog2(sc->device->sector_size)) * 8;
378 	}
379 
380 	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
381 		err = iser_prepare_read_cmd(task);
382 		if (err)
383 			goto send_command_error;
384 	}
385 	if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
386 		err = iser_prepare_write_cmd(task,
387 					     task->imm_count,
388 				             task->imm_count +
389 					     task->unsol_r2t.data_length,
390 					     edtl);
391 		if (err)
392 			goto send_command_error;
393 	}
394 
395 	iser_task->status = ISER_TASK_STATUS_STARTED;
396 
397 	err = iser_post_send(&iser_conn->ib_conn, tx_desc);
398 	if (!err)
399 		return 0;
400 
401 send_command_error:
402 	iser_err("conn %p failed task->itt %d err %d\n",conn, task->itt, err);
403 	return err;
404 }
405 
406 /**
407  * iser_send_data_out - send data out PDU
408  * @conn: link to matching iscsi connection
409  * @task: SCSI command task
410  * @hdr: pointer to the LLD's iSCSI message header
411  */
412 int iser_send_data_out(struct iscsi_conn *conn, struct iscsi_task *task,
413 		       struct iscsi_data *hdr)
414 {
415 	struct iser_conn *iser_conn = conn->dd_data;
416 	struct iscsi_iser_task *iser_task = task->dd_data;
417 	struct iser_tx_desc *tx_desc;
418 	struct iser_mem_reg *mem_reg;
419 	unsigned long buf_offset;
420 	unsigned long data_seg_len;
421 	uint32_t itt;
422 	int err;
423 	struct ib_sge *tx_dsg;
424 
425 	itt = (__force uint32_t)hdr->itt;
426 	data_seg_len = ntoh24(hdr->dlength);
427 	buf_offset   = ntohl(hdr->offset);
428 
429 	iser_dbg("%s itt %d dseg_len %d offset %d\n",
430 		 __func__,(int)itt,(int)data_seg_len,(int)buf_offset);
431 
432 	tx_desc = kmem_cache_zalloc(ig.desc_cache, GFP_ATOMIC);
433 	if (!tx_desc)
434 		return -ENOMEM;
435 
436 	tx_desc->type = ISCSI_TX_DATAOUT;
437 	tx_desc->cqe.done = iser_dataout_comp;
438 	tx_desc->iser_header.flags = ISER_VER;
439 	memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));
440 
441 	/* build the tx desc */
442 	err = iser_initialize_task_headers(task, tx_desc);
443 	if (err)
444 		goto send_data_out_error;
445 
446 	mem_reg = &iser_task->rdma_reg[ISER_DIR_OUT];
447 	tx_dsg = &tx_desc->tx_sg[1];
448 	tx_dsg->addr = mem_reg->sge.addr + buf_offset;
449 	tx_dsg->length = data_seg_len;
450 	tx_dsg->lkey = mem_reg->sge.lkey;
451 	tx_desc->num_sge = 2;
452 
453 	if (buf_offset + data_seg_len > iser_task->data[ISER_DIR_OUT].data_len) {
454 		iser_err("Offset:%ld & DSL:%ld in Data-Out inconsistent with total len:%ld, itt:%d\n",
455 			 buf_offset, data_seg_len,
456 			 iser_task->data[ISER_DIR_OUT].data_len, itt);
457 		err = -EINVAL;
458 		goto send_data_out_error;
459 	}
460 	iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
461 		 itt, buf_offset, data_seg_len);
462 
463 	err = iser_post_send(&iser_conn->ib_conn, tx_desc);
464 	if (!err)
465 		return 0;
466 
467 send_data_out_error:
468 	kmem_cache_free(ig.desc_cache, tx_desc);
469 	iser_err("conn %p failed err %d\n", conn, err);
470 	return err;
471 }
472 
473 int iser_send_control(struct iscsi_conn *conn, struct iscsi_task *task)
474 {
475 	struct iser_conn *iser_conn = conn->dd_data;
476 	struct iscsi_iser_task *iser_task = task->dd_data;
477 	struct iser_tx_desc *mdesc = &iser_task->desc;
478 	unsigned long data_seg_len;
479 	int err = 0;
480 	struct iser_device *device;
481 
482 	/* build the tx desc regd header and add it to the tx desc dto */
483 	iser_create_send_desc(iser_conn, mdesc, ISCSI_TX_CONTROL,
484 			      iser_ctrl_comp);
485 
486 	device = iser_conn->ib_conn.device;
487 
488 	data_seg_len = ntoh24(task->hdr->dlength);
489 
490 	if (data_seg_len > 0) {
491 		struct iser_login_desc *desc = &iser_conn->login_desc;
492 		struct ib_sge *tx_dsg = &mdesc->tx_sg[1];
493 
494 		if (task != conn->login_task) {
495 			iser_err("data present on non login task!!!\n");
496 			goto send_control_error;
497 		}
498 
499 		ib_dma_sync_single_for_cpu(device->ib_device, desc->req_dma,
500 					   task->data_count, DMA_TO_DEVICE);
501 
502 		memcpy(desc->req, task->data, task->data_count);
503 
504 		ib_dma_sync_single_for_device(device->ib_device, desc->req_dma,
505 					      task->data_count, DMA_TO_DEVICE);
506 
507 		tx_dsg->addr = desc->req_dma;
508 		tx_dsg->length = task->data_count;
509 		tx_dsg->lkey = device->pd->local_dma_lkey;
510 		mdesc->num_sge = 2;
511 	}
512 
513 	if (task == conn->login_task) {
514 		iser_dbg("op %x dsl %lx, posting login rx buffer\n",
515 			 task->hdr->opcode, data_seg_len);
516 		err = iser_post_recvl(iser_conn);
517 		if (err)
518 			goto send_control_error;
519 		err = iser_post_rx_bufs(conn, task->hdr);
520 		if (err)
521 			goto send_control_error;
522 	}
523 
524 	err = iser_post_send(&iser_conn->ib_conn, mdesc);
525 	if (!err)
526 		return 0;
527 
528 send_control_error:
529 	iser_err("conn %p failed err %d\n",conn, err);
530 	return err;
531 }
532 
533 void iser_login_rsp(struct ib_cq *cq, struct ib_wc *wc)
534 {
535 	struct ib_conn *ib_conn = wc->qp->qp_context;
536 	struct iser_conn *iser_conn = to_iser_conn(ib_conn);
537 	struct iser_login_desc *desc = iser_login(wc->wr_cqe);
538 	struct iscsi_hdr *hdr;
539 	char *data;
540 	int length;
541 	bool full_feature_phase;
542 
543 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
544 		iser_err_comp(wc, "login_rsp");
545 		return;
546 	}
547 
548 	ib_dma_sync_single_for_cpu(ib_conn->device->ib_device,
549 				   desc->rsp_dma, ISER_RX_LOGIN_SIZE,
550 				   DMA_FROM_DEVICE);
551 
552 	hdr = desc->rsp + sizeof(struct iser_ctrl);
553 	data = desc->rsp + ISER_HEADERS_LEN;
554 	length = wc->byte_len - ISER_HEADERS_LEN;
555 	full_feature_phase = ((hdr->flags & ISCSI_FULL_FEATURE_PHASE) ==
556 			      ISCSI_FULL_FEATURE_PHASE) &&
557 			     (hdr->flags & ISCSI_FLAG_CMD_FINAL);
558 
559 	iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
560 		 hdr->itt, length);
561 
562 	iscsi_iser_recv(iser_conn->iscsi_conn, hdr, data, length);
563 
564 	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
565 				      desc->rsp_dma, ISER_RX_LOGIN_SIZE,
566 				      DMA_FROM_DEVICE);
567 
568 	if (!full_feature_phase ||
569 	    iser_conn->iscsi_conn->session->discovery_sess)
570 		return;
571 
572 	/* Post the first RX buffer that is skipped in iser_post_rx_bufs() */
573 	iser_post_recvm(iser_conn, iser_conn->rx_descs);
574 }
575 
576 static inline int iser_inv_desc(struct iser_fr_desc *desc, u32 rkey)
577 {
578 	if (unlikely((!desc->sig_protected && rkey != desc->rsc.mr->rkey) ||
579 		     (desc->sig_protected && rkey != desc->rsc.sig_mr->rkey))) {
580 		iser_err("Bogus remote invalidation for rkey %#x\n", rkey);
581 		return -EINVAL;
582 	}
583 
584 	if (desc->sig_protected)
585 		desc->rsc.sig_mr->need_inval = false;
586 	else
587 		desc->rsc.mr->need_inval = false;
588 
589 	return 0;
590 }
591 
592 static int iser_check_remote_inv(struct iser_conn *iser_conn, struct ib_wc *wc,
593 				 struct iscsi_hdr *hdr)
594 {
595 	if (wc->wc_flags & IB_WC_WITH_INVALIDATE) {
596 		struct iscsi_task *task;
597 		u32 rkey = wc->ex.invalidate_rkey;
598 
599 		iser_dbg("conn %p: remote invalidation for rkey %#x\n",
600 			 iser_conn, rkey);
601 
602 		if (unlikely(!iser_conn->snd_w_inv)) {
603 			iser_err("conn %p: unexpected remote invalidation, terminating connection\n",
604 				 iser_conn);
605 			return -EPROTO;
606 		}
607 
608 		task = iscsi_itt_to_ctask(iser_conn->iscsi_conn, hdr->itt);
609 		if (likely(task)) {
610 			struct iscsi_iser_task *iser_task = task->dd_data;
611 			struct iser_fr_desc *desc;
612 
613 			if (iser_task->dir[ISER_DIR_IN]) {
614 				desc = iser_task->rdma_reg[ISER_DIR_IN].desc;
615 				if (unlikely(iser_inv_desc(desc, rkey)))
616 					return -EINVAL;
617 			}
618 
619 			if (iser_task->dir[ISER_DIR_OUT]) {
620 				desc = iser_task->rdma_reg[ISER_DIR_OUT].desc;
621 				if (unlikely(iser_inv_desc(desc, rkey)))
622 					return -EINVAL;
623 			}
624 		} else {
625 			iser_err("failed to get task for itt=%d\n", hdr->itt);
626 			return -EINVAL;
627 		}
628 	}
629 
630 	return 0;
631 }
632 
633 
634 void iser_task_rsp(struct ib_cq *cq, struct ib_wc *wc)
635 {
636 	struct ib_conn *ib_conn = wc->qp->qp_context;
637 	struct iser_conn *iser_conn = to_iser_conn(ib_conn);
638 	struct iser_rx_desc *desc = iser_rx(wc->wr_cqe);
639 	struct iscsi_hdr *hdr;
640 	int length, err;
641 
642 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
643 		iser_err_comp(wc, "task_rsp");
644 		return;
645 	}
646 
647 	ib_dma_sync_single_for_cpu(ib_conn->device->ib_device,
648 				   desc->dma_addr, ISER_RX_PAYLOAD_SIZE,
649 				   DMA_FROM_DEVICE);
650 
651 	hdr = &desc->iscsi_header;
652 	length = wc->byte_len - ISER_HEADERS_LEN;
653 
654 	iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
655 		 hdr->itt, length);
656 
657 	if (iser_check_remote_inv(iser_conn, wc, hdr)) {
658 		iscsi_conn_failure(iser_conn->iscsi_conn,
659 				   ISCSI_ERR_CONN_FAILED);
660 		return;
661 	}
662 
663 	iscsi_iser_recv(iser_conn->iscsi_conn, hdr, desc->data, length);
664 
665 	ib_dma_sync_single_for_device(ib_conn->device->ib_device,
666 				      desc->dma_addr, ISER_RX_PAYLOAD_SIZE,
667 				      DMA_FROM_DEVICE);
668 
669 	err = iser_post_recvm(iser_conn, desc);
670 	if (err)
671 		iser_err("posting rx buffer err %d\n", err);
672 }
673 
674 void iser_cmd_comp(struct ib_cq *cq, struct ib_wc *wc)
675 {
676 	if (unlikely(wc->status != IB_WC_SUCCESS))
677 		iser_err_comp(wc, "command");
678 }
679 
680 void iser_ctrl_comp(struct ib_cq *cq, struct ib_wc *wc)
681 {
682 	struct iser_tx_desc *desc = iser_tx(wc->wr_cqe);
683 	struct iscsi_task *task;
684 
685 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
686 		iser_err_comp(wc, "control");
687 		return;
688 	}
689 
690 	/* this arithmetic is legal by libiscsi dd_data allocation */
691 	task = (void *)desc - sizeof(struct iscsi_task);
692 	if (task->hdr->itt == RESERVED_ITT)
693 		iscsi_put_task(task);
694 }
695 
696 void iser_dataout_comp(struct ib_cq *cq, struct ib_wc *wc)
697 {
698 	struct iser_tx_desc *desc = iser_tx(wc->wr_cqe);
699 	struct ib_conn *ib_conn = wc->qp->qp_context;
700 	struct iser_device *device = ib_conn->device;
701 
702 	if (unlikely(wc->status != IB_WC_SUCCESS))
703 		iser_err_comp(wc, "dataout");
704 
705 	ib_dma_unmap_single(device->ib_device, desc->dma_addr,
706 			    ISER_HEADERS_LEN, DMA_TO_DEVICE);
707 	kmem_cache_free(ig.desc_cache, desc);
708 }
709 
710 void iser_task_rdma_init(struct iscsi_iser_task *iser_task)
711 
712 {
713 	iser_task->status = ISER_TASK_STATUS_INIT;
714 
715 	iser_task->dir[ISER_DIR_IN] = 0;
716 	iser_task->dir[ISER_DIR_OUT] = 0;
717 
718 	iser_task->data[ISER_DIR_IN].data_len  = 0;
719 	iser_task->data[ISER_DIR_OUT].data_len = 0;
720 
721 	iser_task->prot[ISER_DIR_IN].data_len  = 0;
722 	iser_task->prot[ISER_DIR_OUT].data_len = 0;
723 
724 	iser_task->prot[ISER_DIR_IN].dma_nents = 0;
725 	iser_task->prot[ISER_DIR_OUT].dma_nents = 0;
726 
727 	memset(&iser_task->rdma_reg[ISER_DIR_IN], 0,
728 	       sizeof(struct iser_mem_reg));
729 	memset(&iser_task->rdma_reg[ISER_DIR_OUT], 0,
730 	       sizeof(struct iser_mem_reg));
731 }
732 
733 void iser_task_rdma_finalize(struct iscsi_iser_task *iser_task)
734 {
735 
736 	if (iser_task->dir[ISER_DIR_IN]) {
737 		iser_unreg_mem_fastreg(iser_task, ISER_DIR_IN);
738 		iser_dma_unmap_task_data(iser_task, ISER_DIR_IN,
739 					 DMA_FROM_DEVICE);
740 	}
741 
742 	if (iser_task->dir[ISER_DIR_OUT]) {
743 		iser_unreg_mem_fastreg(iser_task, ISER_DIR_OUT);
744 		iser_dma_unmap_task_data(iser_task, ISER_DIR_OUT,
745 					 DMA_TO_DEVICE);
746 	}
747 }
748