xref: /linux/drivers/nvme/target/rdma.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * NVMe over Fabrics RDMA target.
3  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/atomic.h>
16 #include <linux/ctype.h>
17 #include <linux/delay.h>
18 #include <linux/err.h>
19 #include <linux/init.h>
20 #include <linux/module.h>
21 #include <linux/nvme.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
24 #include <linux/wait.h>
25 #include <linux/inet.h>
26 #include <asm/unaligned.h>
27 
28 #include <rdma/ib_verbs.h>
29 #include <rdma/rdma_cm.h>
30 #include <rdma/rw.h>
31 
32 #include <linux/nvme-rdma.h>
33 #include "nvmet.h"
34 
35 /*
36  * We allow up to a page of inline data to go with the SQE
37  */
38 #define NVMET_RDMA_INLINE_DATA_SIZE	PAGE_SIZE
39 
40 struct nvmet_rdma_cmd {
41 	struct ib_sge		sge[2];
42 	struct ib_cqe		cqe;
43 	struct ib_recv_wr	wr;
44 	struct scatterlist	inline_sg;
45 	struct page		*inline_page;
46 	struct nvme_command     *nvme_cmd;
47 	struct nvmet_rdma_queue	*queue;
48 };
49 
50 enum {
51 	NVMET_RDMA_REQ_INLINE_DATA	= (1 << 0),
52 	NVMET_RDMA_REQ_INVALIDATE_RKEY	= (1 << 1),
53 };
54 
55 struct nvmet_rdma_rsp {
56 	struct ib_sge		send_sge;
57 	struct ib_cqe		send_cqe;
58 	struct ib_send_wr	send_wr;
59 
60 	struct nvmet_rdma_cmd	*cmd;
61 	struct nvmet_rdma_queue	*queue;
62 
63 	struct ib_cqe		read_cqe;
64 	struct rdma_rw_ctx	rw;
65 
66 	struct nvmet_req	req;
67 
68 	u8			n_rdma;
69 	u32			flags;
70 	u32			invalidate_rkey;
71 
72 	struct list_head	wait_list;
73 	struct list_head	free_list;
74 };
75 
76 enum nvmet_rdma_queue_state {
77 	NVMET_RDMA_Q_CONNECTING,
78 	NVMET_RDMA_Q_LIVE,
79 	NVMET_RDMA_Q_DISCONNECTING,
80 	NVMET_RDMA_IN_DEVICE_REMOVAL,
81 };
82 
83 struct nvmet_rdma_queue {
84 	struct rdma_cm_id	*cm_id;
85 	struct nvmet_port	*port;
86 	struct ib_cq		*cq;
87 	atomic_t		sq_wr_avail;
88 	struct nvmet_rdma_device *dev;
89 	spinlock_t		state_lock;
90 	enum nvmet_rdma_queue_state state;
91 	struct nvmet_cq		nvme_cq;
92 	struct nvmet_sq		nvme_sq;
93 
94 	struct nvmet_rdma_rsp	*rsps;
95 	struct list_head	free_rsps;
96 	spinlock_t		rsps_lock;
97 	struct nvmet_rdma_cmd	*cmds;
98 
99 	struct work_struct	release_work;
100 	struct list_head	rsp_wait_list;
101 	struct list_head	rsp_wr_wait_list;
102 	spinlock_t		rsp_wr_wait_lock;
103 
104 	int			idx;
105 	int			host_qid;
106 	int			recv_queue_size;
107 	int			send_queue_size;
108 
109 	struct list_head	queue_list;
110 };
111 
112 struct nvmet_rdma_device {
113 	struct ib_device	*device;
114 	struct ib_pd		*pd;
115 	struct ib_srq		*srq;
116 	struct nvmet_rdma_cmd	*srq_cmds;
117 	size_t			srq_size;
118 	struct kref		ref;
119 	struct list_head	entry;
120 };
121 
122 static bool nvmet_rdma_use_srq;
123 module_param_named(use_srq, nvmet_rdma_use_srq, bool, 0444);
124 MODULE_PARM_DESC(use_srq, "Use shared receive queue.");
125 
126 static DEFINE_IDA(nvmet_rdma_queue_ida);
127 static LIST_HEAD(nvmet_rdma_queue_list);
128 static DEFINE_MUTEX(nvmet_rdma_queue_mutex);
129 
130 static LIST_HEAD(device_list);
131 static DEFINE_MUTEX(device_list_mutex);
132 
133 static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp);
134 static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc);
135 static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc);
136 static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc);
137 static void nvmet_rdma_qp_event(struct ib_event *event, void *priv);
138 static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue);
139 
140 static struct nvmet_fabrics_ops nvmet_rdma_ops;
141 
142 /* XXX: really should move to a generic header sooner or later.. */
143 static inline u32 get_unaligned_le24(const u8 *p)
144 {
145 	return (u32)p[0] | (u32)p[1] << 8 | (u32)p[2] << 16;
146 }
147 
148 static inline bool nvmet_rdma_need_data_in(struct nvmet_rdma_rsp *rsp)
149 {
150 	return nvme_is_write(rsp->req.cmd) &&
151 		rsp->req.data_len &&
152 		!(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
153 }
154 
155 static inline bool nvmet_rdma_need_data_out(struct nvmet_rdma_rsp *rsp)
156 {
157 	return !nvme_is_write(rsp->req.cmd) &&
158 		rsp->req.data_len &&
159 		!rsp->req.rsp->status &&
160 		!(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
161 }
162 
163 static inline struct nvmet_rdma_rsp *
164 nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue)
165 {
166 	struct nvmet_rdma_rsp *rsp;
167 	unsigned long flags;
168 
169 	spin_lock_irqsave(&queue->rsps_lock, flags);
170 	rsp = list_first_entry(&queue->free_rsps,
171 				struct nvmet_rdma_rsp, free_list);
172 	list_del(&rsp->free_list);
173 	spin_unlock_irqrestore(&queue->rsps_lock, flags);
174 
175 	return rsp;
176 }
177 
178 static inline void
179 nvmet_rdma_put_rsp(struct nvmet_rdma_rsp *rsp)
180 {
181 	unsigned long flags;
182 
183 	spin_lock_irqsave(&rsp->queue->rsps_lock, flags);
184 	list_add_tail(&rsp->free_list, &rsp->queue->free_rsps);
185 	spin_unlock_irqrestore(&rsp->queue->rsps_lock, flags);
186 }
187 
188 static void nvmet_rdma_free_sgl(struct scatterlist *sgl, unsigned int nents)
189 {
190 	struct scatterlist *sg;
191 	int count;
192 
193 	if (!sgl || !nents)
194 		return;
195 
196 	for_each_sg(sgl, sg, nents, count)
197 		__free_page(sg_page(sg));
198 	kfree(sgl);
199 }
200 
201 static int nvmet_rdma_alloc_sgl(struct scatterlist **sgl, unsigned int *nents,
202 		u32 length)
203 {
204 	struct scatterlist *sg;
205 	struct page *page;
206 	unsigned int nent;
207 	int i = 0;
208 
209 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
210 	sg = kmalloc_array(nent, sizeof(struct scatterlist), GFP_KERNEL);
211 	if (!sg)
212 		goto out;
213 
214 	sg_init_table(sg, nent);
215 
216 	while (length) {
217 		u32 page_len = min_t(u32, length, PAGE_SIZE);
218 
219 		page = alloc_page(GFP_KERNEL);
220 		if (!page)
221 			goto out_free_pages;
222 
223 		sg_set_page(&sg[i], page, page_len, 0);
224 		length -= page_len;
225 		i++;
226 	}
227 	*sgl = sg;
228 	*nents = nent;
229 	return 0;
230 
231 out_free_pages:
232 	while (i > 0) {
233 		i--;
234 		__free_page(sg_page(&sg[i]));
235 	}
236 	kfree(sg);
237 out:
238 	return NVME_SC_INTERNAL;
239 }
240 
241 static int nvmet_rdma_alloc_cmd(struct nvmet_rdma_device *ndev,
242 			struct nvmet_rdma_cmd *c, bool admin)
243 {
244 	/* NVMe command / RDMA RECV */
245 	c->nvme_cmd = kmalloc(sizeof(*c->nvme_cmd), GFP_KERNEL);
246 	if (!c->nvme_cmd)
247 		goto out;
248 
249 	c->sge[0].addr = ib_dma_map_single(ndev->device, c->nvme_cmd,
250 			sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
251 	if (ib_dma_mapping_error(ndev->device, c->sge[0].addr))
252 		goto out_free_cmd;
253 
254 	c->sge[0].length = sizeof(*c->nvme_cmd);
255 	c->sge[0].lkey = ndev->pd->local_dma_lkey;
256 
257 	if (!admin) {
258 		c->inline_page = alloc_pages(GFP_KERNEL,
259 				get_order(NVMET_RDMA_INLINE_DATA_SIZE));
260 		if (!c->inline_page)
261 			goto out_unmap_cmd;
262 		c->sge[1].addr = ib_dma_map_page(ndev->device,
263 				c->inline_page, 0, NVMET_RDMA_INLINE_DATA_SIZE,
264 				DMA_FROM_DEVICE);
265 		if (ib_dma_mapping_error(ndev->device, c->sge[1].addr))
266 			goto out_free_inline_page;
267 		c->sge[1].length = NVMET_RDMA_INLINE_DATA_SIZE;
268 		c->sge[1].lkey = ndev->pd->local_dma_lkey;
269 	}
270 
271 	c->cqe.done = nvmet_rdma_recv_done;
272 
273 	c->wr.wr_cqe = &c->cqe;
274 	c->wr.sg_list = c->sge;
275 	c->wr.num_sge = admin ? 1 : 2;
276 
277 	return 0;
278 
279 out_free_inline_page:
280 	if (!admin) {
281 		__free_pages(c->inline_page,
282 				get_order(NVMET_RDMA_INLINE_DATA_SIZE));
283 	}
284 out_unmap_cmd:
285 	ib_dma_unmap_single(ndev->device, c->sge[0].addr,
286 			sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
287 out_free_cmd:
288 	kfree(c->nvme_cmd);
289 
290 out:
291 	return -ENOMEM;
292 }
293 
294 static void nvmet_rdma_free_cmd(struct nvmet_rdma_device *ndev,
295 		struct nvmet_rdma_cmd *c, bool admin)
296 {
297 	if (!admin) {
298 		ib_dma_unmap_page(ndev->device, c->sge[1].addr,
299 				NVMET_RDMA_INLINE_DATA_SIZE, DMA_FROM_DEVICE);
300 		__free_pages(c->inline_page,
301 				get_order(NVMET_RDMA_INLINE_DATA_SIZE));
302 	}
303 	ib_dma_unmap_single(ndev->device, c->sge[0].addr,
304 				sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
305 	kfree(c->nvme_cmd);
306 }
307 
308 static struct nvmet_rdma_cmd *
309 nvmet_rdma_alloc_cmds(struct nvmet_rdma_device *ndev,
310 		int nr_cmds, bool admin)
311 {
312 	struct nvmet_rdma_cmd *cmds;
313 	int ret = -EINVAL, i;
314 
315 	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_rdma_cmd), GFP_KERNEL);
316 	if (!cmds)
317 		goto out;
318 
319 	for (i = 0; i < nr_cmds; i++) {
320 		ret = nvmet_rdma_alloc_cmd(ndev, cmds + i, admin);
321 		if (ret)
322 			goto out_free;
323 	}
324 
325 	return cmds;
326 
327 out_free:
328 	while (--i >= 0)
329 		nvmet_rdma_free_cmd(ndev, cmds + i, admin);
330 	kfree(cmds);
331 out:
332 	return ERR_PTR(ret);
333 }
334 
335 static void nvmet_rdma_free_cmds(struct nvmet_rdma_device *ndev,
336 		struct nvmet_rdma_cmd *cmds, int nr_cmds, bool admin)
337 {
338 	int i;
339 
340 	for (i = 0; i < nr_cmds; i++)
341 		nvmet_rdma_free_cmd(ndev, cmds + i, admin);
342 	kfree(cmds);
343 }
344 
345 static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev,
346 		struct nvmet_rdma_rsp *r)
347 {
348 	/* NVMe CQE / RDMA SEND */
349 	r->req.rsp = kmalloc(sizeof(*r->req.rsp), GFP_KERNEL);
350 	if (!r->req.rsp)
351 		goto out;
352 
353 	r->send_sge.addr = ib_dma_map_single(ndev->device, r->req.rsp,
354 			sizeof(*r->req.rsp), DMA_TO_DEVICE);
355 	if (ib_dma_mapping_error(ndev->device, r->send_sge.addr))
356 		goto out_free_rsp;
357 
358 	r->send_sge.length = sizeof(*r->req.rsp);
359 	r->send_sge.lkey = ndev->pd->local_dma_lkey;
360 
361 	r->send_cqe.done = nvmet_rdma_send_done;
362 
363 	r->send_wr.wr_cqe = &r->send_cqe;
364 	r->send_wr.sg_list = &r->send_sge;
365 	r->send_wr.num_sge = 1;
366 	r->send_wr.send_flags = IB_SEND_SIGNALED;
367 
368 	/* Data In / RDMA READ */
369 	r->read_cqe.done = nvmet_rdma_read_data_done;
370 	return 0;
371 
372 out_free_rsp:
373 	kfree(r->req.rsp);
374 out:
375 	return -ENOMEM;
376 }
377 
378 static void nvmet_rdma_free_rsp(struct nvmet_rdma_device *ndev,
379 		struct nvmet_rdma_rsp *r)
380 {
381 	ib_dma_unmap_single(ndev->device, r->send_sge.addr,
382 				sizeof(*r->req.rsp), DMA_TO_DEVICE);
383 	kfree(r->req.rsp);
384 }
385 
386 static int
387 nvmet_rdma_alloc_rsps(struct nvmet_rdma_queue *queue)
388 {
389 	struct nvmet_rdma_device *ndev = queue->dev;
390 	int nr_rsps = queue->recv_queue_size * 2;
391 	int ret = -EINVAL, i;
392 
393 	queue->rsps = kcalloc(nr_rsps, sizeof(struct nvmet_rdma_rsp),
394 			GFP_KERNEL);
395 	if (!queue->rsps)
396 		goto out;
397 
398 	for (i = 0; i < nr_rsps; i++) {
399 		struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
400 
401 		ret = nvmet_rdma_alloc_rsp(ndev, rsp);
402 		if (ret)
403 			goto out_free;
404 
405 		list_add_tail(&rsp->free_list, &queue->free_rsps);
406 	}
407 
408 	return 0;
409 
410 out_free:
411 	while (--i >= 0) {
412 		struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
413 
414 		list_del(&rsp->free_list);
415 		nvmet_rdma_free_rsp(ndev, rsp);
416 	}
417 	kfree(queue->rsps);
418 out:
419 	return ret;
420 }
421 
422 static void nvmet_rdma_free_rsps(struct nvmet_rdma_queue *queue)
423 {
424 	struct nvmet_rdma_device *ndev = queue->dev;
425 	int i, nr_rsps = queue->recv_queue_size * 2;
426 
427 	for (i = 0; i < nr_rsps; i++) {
428 		struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
429 
430 		list_del(&rsp->free_list);
431 		nvmet_rdma_free_rsp(ndev, rsp);
432 	}
433 	kfree(queue->rsps);
434 }
435 
436 static int nvmet_rdma_post_recv(struct nvmet_rdma_device *ndev,
437 		struct nvmet_rdma_cmd *cmd)
438 {
439 	struct ib_recv_wr *bad_wr;
440 
441 	if (ndev->srq)
442 		return ib_post_srq_recv(ndev->srq, &cmd->wr, &bad_wr);
443 	return ib_post_recv(cmd->queue->cm_id->qp, &cmd->wr, &bad_wr);
444 }
445 
446 static void nvmet_rdma_process_wr_wait_list(struct nvmet_rdma_queue *queue)
447 {
448 	spin_lock(&queue->rsp_wr_wait_lock);
449 	while (!list_empty(&queue->rsp_wr_wait_list)) {
450 		struct nvmet_rdma_rsp *rsp;
451 		bool ret;
452 
453 		rsp = list_entry(queue->rsp_wr_wait_list.next,
454 				struct nvmet_rdma_rsp, wait_list);
455 		list_del(&rsp->wait_list);
456 
457 		spin_unlock(&queue->rsp_wr_wait_lock);
458 		ret = nvmet_rdma_execute_command(rsp);
459 		spin_lock(&queue->rsp_wr_wait_lock);
460 
461 		if (!ret) {
462 			list_add(&rsp->wait_list, &queue->rsp_wr_wait_list);
463 			break;
464 		}
465 	}
466 	spin_unlock(&queue->rsp_wr_wait_lock);
467 }
468 
469 
470 static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp)
471 {
472 	struct nvmet_rdma_queue *queue = rsp->queue;
473 
474 	atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
475 
476 	if (rsp->n_rdma) {
477 		rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
478 				queue->cm_id->port_num, rsp->req.sg,
479 				rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
480 	}
481 
482 	if (rsp->req.sg != &rsp->cmd->inline_sg)
483 		nvmet_rdma_free_sgl(rsp->req.sg, rsp->req.sg_cnt);
484 
485 	if (unlikely(!list_empty_careful(&queue->rsp_wr_wait_list)))
486 		nvmet_rdma_process_wr_wait_list(queue);
487 
488 	nvmet_rdma_put_rsp(rsp);
489 }
490 
491 static void nvmet_rdma_error_comp(struct nvmet_rdma_queue *queue)
492 {
493 	if (queue->nvme_sq.ctrl) {
494 		nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
495 	} else {
496 		/*
497 		 * we didn't setup the controller yet in case
498 		 * of admin connect error, just disconnect and
499 		 * cleanup the queue
500 		 */
501 		nvmet_rdma_queue_disconnect(queue);
502 	}
503 }
504 
505 static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
506 {
507 	struct nvmet_rdma_rsp *rsp =
508 		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, send_cqe);
509 
510 	nvmet_rdma_release_rsp(rsp);
511 
512 	if (unlikely(wc->status != IB_WC_SUCCESS &&
513 		     wc->status != IB_WC_WR_FLUSH_ERR)) {
514 		pr_err("SEND for CQE 0x%p failed with status %s (%d).\n",
515 			wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
516 		nvmet_rdma_error_comp(rsp->queue);
517 	}
518 }
519 
520 static void nvmet_rdma_queue_response(struct nvmet_req *req)
521 {
522 	struct nvmet_rdma_rsp *rsp =
523 		container_of(req, struct nvmet_rdma_rsp, req);
524 	struct rdma_cm_id *cm_id = rsp->queue->cm_id;
525 	struct ib_send_wr *first_wr, *bad_wr;
526 
527 	if (rsp->flags & NVMET_RDMA_REQ_INVALIDATE_RKEY) {
528 		rsp->send_wr.opcode = IB_WR_SEND_WITH_INV;
529 		rsp->send_wr.ex.invalidate_rkey = rsp->invalidate_rkey;
530 	} else {
531 		rsp->send_wr.opcode = IB_WR_SEND;
532 	}
533 
534 	if (nvmet_rdma_need_data_out(rsp))
535 		first_wr = rdma_rw_ctx_wrs(&rsp->rw, cm_id->qp,
536 				cm_id->port_num, NULL, &rsp->send_wr);
537 	else
538 		first_wr = &rsp->send_wr;
539 
540 	nvmet_rdma_post_recv(rsp->queue->dev, rsp->cmd);
541 	if (ib_post_send(cm_id->qp, first_wr, &bad_wr)) {
542 		pr_err("sending cmd response failed\n");
543 		nvmet_rdma_release_rsp(rsp);
544 	}
545 }
546 
547 static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc)
548 {
549 	struct nvmet_rdma_rsp *rsp =
550 		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, read_cqe);
551 	struct nvmet_rdma_queue *queue = cq->cq_context;
552 
553 	WARN_ON(rsp->n_rdma <= 0);
554 	atomic_add(rsp->n_rdma, &queue->sq_wr_avail);
555 	rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
556 			queue->cm_id->port_num, rsp->req.sg,
557 			rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
558 	rsp->n_rdma = 0;
559 
560 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
561 		nvmet_rdma_release_rsp(rsp);
562 		if (wc->status != IB_WC_WR_FLUSH_ERR) {
563 			pr_info("RDMA READ for CQE 0x%p failed with status %s (%d).\n",
564 				wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
565 			nvmet_rdma_error_comp(queue);
566 		}
567 		return;
568 	}
569 
570 	rsp->req.execute(&rsp->req);
571 }
572 
573 static void nvmet_rdma_use_inline_sg(struct nvmet_rdma_rsp *rsp, u32 len,
574 		u64 off)
575 {
576 	sg_init_table(&rsp->cmd->inline_sg, 1);
577 	sg_set_page(&rsp->cmd->inline_sg, rsp->cmd->inline_page, len, off);
578 	rsp->req.sg = &rsp->cmd->inline_sg;
579 	rsp->req.sg_cnt = 1;
580 }
581 
582 static u16 nvmet_rdma_map_sgl_inline(struct nvmet_rdma_rsp *rsp)
583 {
584 	struct nvme_sgl_desc *sgl = &rsp->req.cmd->common.dptr.sgl;
585 	u64 off = le64_to_cpu(sgl->addr);
586 	u32 len = le32_to_cpu(sgl->length);
587 
588 	if (!nvme_is_write(rsp->req.cmd))
589 		return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
590 
591 	if (off + len > NVMET_RDMA_INLINE_DATA_SIZE) {
592 		pr_err("invalid inline data offset!\n");
593 		return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
594 	}
595 
596 	/* no data command? */
597 	if (!len)
598 		return 0;
599 
600 	nvmet_rdma_use_inline_sg(rsp, len, off);
601 	rsp->flags |= NVMET_RDMA_REQ_INLINE_DATA;
602 	return 0;
603 }
604 
605 static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp,
606 		struct nvme_keyed_sgl_desc *sgl, bool invalidate)
607 {
608 	struct rdma_cm_id *cm_id = rsp->queue->cm_id;
609 	u64 addr = le64_to_cpu(sgl->addr);
610 	u32 len = get_unaligned_le24(sgl->length);
611 	u32 key = get_unaligned_le32(sgl->key);
612 	int ret;
613 	u16 status;
614 
615 	/* no data command? */
616 	if (!len)
617 		return 0;
618 
619 	status = nvmet_rdma_alloc_sgl(&rsp->req.sg, &rsp->req.sg_cnt,
620 			len);
621 	if (status)
622 		return status;
623 
624 	ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num,
625 			rsp->req.sg, rsp->req.sg_cnt, 0, addr, key,
626 			nvmet_data_dir(&rsp->req));
627 	if (ret < 0)
628 		return NVME_SC_INTERNAL;
629 	rsp->n_rdma += ret;
630 
631 	if (invalidate) {
632 		rsp->invalidate_rkey = key;
633 		rsp->flags |= NVMET_RDMA_REQ_INVALIDATE_RKEY;
634 	}
635 
636 	return 0;
637 }
638 
639 static u16 nvmet_rdma_map_sgl(struct nvmet_rdma_rsp *rsp)
640 {
641 	struct nvme_keyed_sgl_desc *sgl = &rsp->req.cmd->common.dptr.ksgl;
642 
643 	switch (sgl->type >> 4) {
644 	case NVME_SGL_FMT_DATA_DESC:
645 		switch (sgl->type & 0xf) {
646 		case NVME_SGL_FMT_OFFSET:
647 			return nvmet_rdma_map_sgl_inline(rsp);
648 		default:
649 			pr_err("invalid SGL subtype: %#x\n", sgl->type);
650 			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
651 		}
652 	case NVME_KEY_SGL_FMT_DATA_DESC:
653 		switch (sgl->type & 0xf) {
654 		case NVME_SGL_FMT_ADDRESS | NVME_SGL_FMT_INVALIDATE:
655 			return nvmet_rdma_map_sgl_keyed(rsp, sgl, true);
656 		case NVME_SGL_FMT_ADDRESS:
657 			return nvmet_rdma_map_sgl_keyed(rsp, sgl, false);
658 		default:
659 			pr_err("invalid SGL subtype: %#x\n", sgl->type);
660 			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
661 		}
662 	default:
663 		pr_err("invalid SGL type: %#x\n", sgl->type);
664 		return NVME_SC_SGL_INVALID_TYPE | NVME_SC_DNR;
665 	}
666 }
667 
668 static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp)
669 {
670 	struct nvmet_rdma_queue *queue = rsp->queue;
671 
672 	if (unlikely(atomic_sub_return(1 + rsp->n_rdma,
673 			&queue->sq_wr_avail) < 0)) {
674 		pr_debug("IB send queue full (needed %d): queue %u cntlid %u\n",
675 				1 + rsp->n_rdma, queue->idx,
676 				queue->nvme_sq.ctrl->cntlid);
677 		atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
678 		return false;
679 	}
680 
681 	if (nvmet_rdma_need_data_in(rsp)) {
682 		if (rdma_rw_ctx_post(&rsp->rw, queue->cm_id->qp,
683 				queue->cm_id->port_num, &rsp->read_cqe, NULL))
684 			nvmet_req_complete(&rsp->req, NVME_SC_DATA_XFER_ERROR);
685 	} else {
686 		rsp->req.execute(&rsp->req);
687 	}
688 
689 	return true;
690 }
691 
692 static void nvmet_rdma_handle_command(struct nvmet_rdma_queue *queue,
693 		struct nvmet_rdma_rsp *cmd)
694 {
695 	u16 status;
696 
697 	cmd->queue = queue;
698 	cmd->n_rdma = 0;
699 	cmd->req.port = queue->port;
700 
701 	if (!nvmet_req_init(&cmd->req, &queue->nvme_cq,
702 			&queue->nvme_sq, &nvmet_rdma_ops))
703 		return;
704 
705 	status = nvmet_rdma_map_sgl(cmd);
706 	if (status)
707 		goto out_err;
708 
709 	if (unlikely(!nvmet_rdma_execute_command(cmd))) {
710 		spin_lock(&queue->rsp_wr_wait_lock);
711 		list_add_tail(&cmd->wait_list, &queue->rsp_wr_wait_list);
712 		spin_unlock(&queue->rsp_wr_wait_lock);
713 	}
714 
715 	return;
716 
717 out_err:
718 	nvmet_req_complete(&cmd->req, status);
719 }
720 
721 static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
722 {
723 	struct nvmet_rdma_cmd *cmd =
724 		container_of(wc->wr_cqe, struct nvmet_rdma_cmd, cqe);
725 	struct nvmet_rdma_queue *queue = cq->cq_context;
726 	struct nvmet_rdma_rsp *rsp;
727 
728 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
729 		if (wc->status != IB_WC_WR_FLUSH_ERR) {
730 			pr_err("RECV for CQE 0x%p failed with status %s (%d)\n",
731 				wc->wr_cqe, ib_wc_status_msg(wc->status),
732 				wc->status);
733 			nvmet_rdma_error_comp(queue);
734 		}
735 		return;
736 	}
737 
738 	if (unlikely(wc->byte_len < sizeof(struct nvme_command))) {
739 		pr_err("Ctrl Fatal Error: capsule size less than 64 bytes\n");
740 		nvmet_rdma_error_comp(queue);
741 		return;
742 	}
743 
744 	cmd->queue = queue;
745 	rsp = nvmet_rdma_get_rsp(queue);
746 	rsp->cmd = cmd;
747 	rsp->flags = 0;
748 	rsp->req.cmd = cmd->nvme_cmd;
749 
750 	if (unlikely(queue->state != NVMET_RDMA_Q_LIVE)) {
751 		unsigned long flags;
752 
753 		spin_lock_irqsave(&queue->state_lock, flags);
754 		if (queue->state == NVMET_RDMA_Q_CONNECTING)
755 			list_add_tail(&rsp->wait_list, &queue->rsp_wait_list);
756 		else
757 			nvmet_rdma_put_rsp(rsp);
758 		spin_unlock_irqrestore(&queue->state_lock, flags);
759 		return;
760 	}
761 
762 	nvmet_rdma_handle_command(queue, rsp);
763 }
764 
765 static void nvmet_rdma_destroy_srq(struct nvmet_rdma_device *ndev)
766 {
767 	if (!ndev->srq)
768 		return;
769 
770 	nvmet_rdma_free_cmds(ndev, ndev->srq_cmds, ndev->srq_size, false);
771 	ib_destroy_srq(ndev->srq);
772 }
773 
774 static int nvmet_rdma_init_srq(struct nvmet_rdma_device *ndev)
775 {
776 	struct ib_srq_init_attr srq_attr = { NULL, };
777 	struct ib_srq *srq;
778 	size_t srq_size;
779 	int ret, i;
780 
781 	srq_size = 4095;	/* XXX: tune */
782 
783 	srq_attr.attr.max_wr = srq_size;
784 	srq_attr.attr.max_sge = 2;
785 	srq_attr.attr.srq_limit = 0;
786 	srq_attr.srq_type = IB_SRQT_BASIC;
787 	srq = ib_create_srq(ndev->pd, &srq_attr);
788 	if (IS_ERR(srq)) {
789 		/*
790 		 * If SRQs aren't supported we just go ahead and use normal
791 		 * non-shared receive queues.
792 		 */
793 		pr_info("SRQ requested but not supported.\n");
794 		return 0;
795 	}
796 
797 	ndev->srq_cmds = nvmet_rdma_alloc_cmds(ndev, srq_size, false);
798 	if (IS_ERR(ndev->srq_cmds)) {
799 		ret = PTR_ERR(ndev->srq_cmds);
800 		goto out_destroy_srq;
801 	}
802 
803 	ndev->srq = srq;
804 	ndev->srq_size = srq_size;
805 
806 	for (i = 0; i < srq_size; i++)
807 		nvmet_rdma_post_recv(ndev, &ndev->srq_cmds[i]);
808 
809 	return 0;
810 
811 out_destroy_srq:
812 	ib_destroy_srq(srq);
813 	return ret;
814 }
815 
816 static void nvmet_rdma_free_dev(struct kref *ref)
817 {
818 	struct nvmet_rdma_device *ndev =
819 		container_of(ref, struct nvmet_rdma_device, ref);
820 
821 	mutex_lock(&device_list_mutex);
822 	list_del(&ndev->entry);
823 	mutex_unlock(&device_list_mutex);
824 
825 	nvmet_rdma_destroy_srq(ndev);
826 	ib_dealloc_pd(ndev->pd);
827 
828 	kfree(ndev);
829 }
830 
831 static struct nvmet_rdma_device *
832 nvmet_rdma_find_get_device(struct rdma_cm_id *cm_id)
833 {
834 	struct nvmet_rdma_device *ndev;
835 	int ret;
836 
837 	mutex_lock(&device_list_mutex);
838 	list_for_each_entry(ndev, &device_list, entry) {
839 		if (ndev->device->node_guid == cm_id->device->node_guid &&
840 		    kref_get_unless_zero(&ndev->ref))
841 			goto out_unlock;
842 	}
843 
844 	ndev = kzalloc(sizeof(*ndev), GFP_KERNEL);
845 	if (!ndev)
846 		goto out_err;
847 
848 	ndev->device = cm_id->device;
849 	kref_init(&ndev->ref);
850 
851 	ndev->pd = ib_alloc_pd(ndev->device, 0);
852 	if (IS_ERR(ndev->pd))
853 		goto out_free_dev;
854 
855 	if (nvmet_rdma_use_srq) {
856 		ret = nvmet_rdma_init_srq(ndev);
857 		if (ret)
858 			goto out_free_pd;
859 	}
860 
861 	list_add(&ndev->entry, &device_list);
862 out_unlock:
863 	mutex_unlock(&device_list_mutex);
864 	pr_debug("added %s.\n", ndev->device->name);
865 	return ndev;
866 
867 out_free_pd:
868 	ib_dealloc_pd(ndev->pd);
869 out_free_dev:
870 	kfree(ndev);
871 out_err:
872 	mutex_unlock(&device_list_mutex);
873 	return NULL;
874 }
875 
876 static int nvmet_rdma_create_queue_ib(struct nvmet_rdma_queue *queue)
877 {
878 	struct ib_qp_init_attr qp_attr;
879 	struct nvmet_rdma_device *ndev = queue->dev;
880 	int comp_vector, nr_cqe, ret, i;
881 
882 	/*
883 	 * Spread the io queues across completion vectors,
884 	 * but still keep all admin queues on vector 0.
885 	 */
886 	comp_vector = !queue->host_qid ? 0 :
887 		queue->idx % ndev->device->num_comp_vectors;
888 
889 	/*
890 	 * Reserve CQ slots for RECV + RDMA_READ/RDMA_WRITE + RDMA_SEND.
891 	 */
892 	nr_cqe = queue->recv_queue_size + 2 * queue->send_queue_size;
893 
894 	queue->cq = ib_alloc_cq(ndev->device, queue,
895 			nr_cqe + 1, comp_vector,
896 			IB_POLL_WORKQUEUE);
897 	if (IS_ERR(queue->cq)) {
898 		ret = PTR_ERR(queue->cq);
899 		pr_err("failed to create CQ cqe= %d ret= %d\n",
900 		       nr_cqe + 1, ret);
901 		goto out;
902 	}
903 
904 	memset(&qp_attr, 0, sizeof(qp_attr));
905 	qp_attr.qp_context = queue;
906 	qp_attr.event_handler = nvmet_rdma_qp_event;
907 	qp_attr.send_cq = queue->cq;
908 	qp_attr.recv_cq = queue->cq;
909 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
910 	qp_attr.qp_type = IB_QPT_RC;
911 	/* +1 for drain */
912 	qp_attr.cap.max_send_wr = queue->send_queue_size + 1;
913 	qp_attr.cap.max_rdma_ctxs = queue->send_queue_size;
914 	qp_attr.cap.max_send_sge = max(ndev->device->attrs.max_sge_rd,
915 					ndev->device->attrs.max_sge);
916 
917 	if (ndev->srq) {
918 		qp_attr.srq = ndev->srq;
919 	} else {
920 		/* +1 for drain */
921 		qp_attr.cap.max_recv_wr = 1 + queue->recv_queue_size;
922 		qp_attr.cap.max_recv_sge = 2;
923 	}
924 
925 	ret = rdma_create_qp(queue->cm_id, ndev->pd, &qp_attr);
926 	if (ret) {
927 		pr_err("failed to create_qp ret= %d\n", ret);
928 		goto err_destroy_cq;
929 	}
930 
931 	atomic_set(&queue->sq_wr_avail, qp_attr.cap.max_send_wr);
932 
933 	pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
934 		 __func__, queue->cq->cqe, qp_attr.cap.max_send_sge,
935 		 qp_attr.cap.max_send_wr, queue->cm_id);
936 
937 	if (!ndev->srq) {
938 		for (i = 0; i < queue->recv_queue_size; i++) {
939 			queue->cmds[i].queue = queue;
940 			nvmet_rdma_post_recv(ndev, &queue->cmds[i]);
941 		}
942 	}
943 
944 out:
945 	return ret;
946 
947 err_destroy_cq:
948 	ib_free_cq(queue->cq);
949 	goto out;
950 }
951 
952 static void nvmet_rdma_destroy_queue_ib(struct nvmet_rdma_queue *queue)
953 {
954 	rdma_destroy_qp(queue->cm_id);
955 	ib_free_cq(queue->cq);
956 }
957 
958 static void nvmet_rdma_free_queue(struct nvmet_rdma_queue *queue)
959 {
960 	pr_info("freeing queue %d\n", queue->idx);
961 
962 	nvmet_sq_destroy(&queue->nvme_sq);
963 
964 	nvmet_rdma_destroy_queue_ib(queue);
965 	if (!queue->dev->srq) {
966 		nvmet_rdma_free_cmds(queue->dev, queue->cmds,
967 				queue->recv_queue_size,
968 				!queue->host_qid);
969 	}
970 	nvmet_rdma_free_rsps(queue);
971 	ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
972 	kfree(queue);
973 }
974 
975 static void nvmet_rdma_release_queue_work(struct work_struct *w)
976 {
977 	struct nvmet_rdma_queue *queue =
978 		container_of(w, struct nvmet_rdma_queue, release_work);
979 	struct rdma_cm_id *cm_id = queue->cm_id;
980 	struct nvmet_rdma_device *dev = queue->dev;
981 	enum nvmet_rdma_queue_state state = queue->state;
982 
983 	nvmet_rdma_free_queue(queue);
984 
985 	if (state != NVMET_RDMA_IN_DEVICE_REMOVAL)
986 		rdma_destroy_id(cm_id);
987 
988 	kref_put(&dev->ref, nvmet_rdma_free_dev);
989 }
990 
991 static int
992 nvmet_rdma_parse_cm_connect_req(struct rdma_conn_param *conn,
993 				struct nvmet_rdma_queue *queue)
994 {
995 	struct nvme_rdma_cm_req *req;
996 
997 	req = (struct nvme_rdma_cm_req *)conn->private_data;
998 	if (!req || conn->private_data_len == 0)
999 		return NVME_RDMA_CM_INVALID_LEN;
1000 
1001 	if (le16_to_cpu(req->recfmt) != NVME_RDMA_CM_FMT_1_0)
1002 		return NVME_RDMA_CM_INVALID_RECFMT;
1003 
1004 	queue->host_qid = le16_to_cpu(req->qid);
1005 
1006 	/*
1007 	 * req->hsqsize corresponds to our recv queue size plus 1
1008 	 * req->hrqsize corresponds to our send queue size
1009 	 */
1010 	queue->recv_queue_size = le16_to_cpu(req->hsqsize) + 1;
1011 	queue->send_queue_size = le16_to_cpu(req->hrqsize);
1012 
1013 	if (!queue->host_qid && queue->recv_queue_size > NVMF_AQ_DEPTH)
1014 		return NVME_RDMA_CM_INVALID_HSQSIZE;
1015 
1016 	/* XXX: Should we enforce some kind of max for IO queues? */
1017 
1018 	return 0;
1019 }
1020 
1021 static int nvmet_rdma_cm_reject(struct rdma_cm_id *cm_id,
1022 				enum nvme_rdma_cm_status status)
1023 {
1024 	struct nvme_rdma_cm_rej rej;
1025 
1026 	rej.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
1027 	rej.sts = cpu_to_le16(status);
1028 
1029 	return rdma_reject(cm_id, (void *)&rej, sizeof(rej));
1030 }
1031 
1032 static struct nvmet_rdma_queue *
1033 nvmet_rdma_alloc_queue(struct nvmet_rdma_device *ndev,
1034 		struct rdma_cm_id *cm_id,
1035 		struct rdma_cm_event *event)
1036 {
1037 	struct nvmet_rdma_queue *queue;
1038 	int ret;
1039 
1040 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1041 	if (!queue) {
1042 		ret = NVME_RDMA_CM_NO_RSC;
1043 		goto out_reject;
1044 	}
1045 
1046 	ret = nvmet_sq_init(&queue->nvme_sq);
1047 	if (ret)
1048 		goto out_free_queue;
1049 
1050 	ret = nvmet_rdma_parse_cm_connect_req(&event->param.conn, queue);
1051 	if (ret)
1052 		goto out_destroy_sq;
1053 
1054 	/*
1055 	 * Schedules the actual release because calling rdma_destroy_id from
1056 	 * inside a CM callback would trigger a deadlock. (great API design..)
1057 	 */
1058 	INIT_WORK(&queue->release_work, nvmet_rdma_release_queue_work);
1059 	queue->dev = ndev;
1060 	queue->cm_id = cm_id;
1061 
1062 	spin_lock_init(&queue->state_lock);
1063 	queue->state = NVMET_RDMA_Q_CONNECTING;
1064 	INIT_LIST_HEAD(&queue->rsp_wait_list);
1065 	INIT_LIST_HEAD(&queue->rsp_wr_wait_list);
1066 	spin_lock_init(&queue->rsp_wr_wait_lock);
1067 	INIT_LIST_HEAD(&queue->free_rsps);
1068 	spin_lock_init(&queue->rsps_lock);
1069 
1070 	queue->idx = ida_simple_get(&nvmet_rdma_queue_ida, 0, 0, GFP_KERNEL);
1071 	if (queue->idx < 0) {
1072 		ret = NVME_RDMA_CM_NO_RSC;
1073 		goto out_free_queue;
1074 	}
1075 
1076 	ret = nvmet_rdma_alloc_rsps(queue);
1077 	if (ret) {
1078 		ret = NVME_RDMA_CM_NO_RSC;
1079 		goto out_ida_remove;
1080 	}
1081 
1082 	if (!ndev->srq) {
1083 		queue->cmds = nvmet_rdma_alloc_cmds(ndev,
1084 				queue->recv_queue_size,
1085 				!queue->host_qid);
1086 		if (IS_ERR(queue->cmds)) {
1087 			ret = NVME_RDMA_CM_NO_RSC;
1088 			goto out_free_responses;
1089 		}
1090 	}
1091 
1092 	ret = nvmet_rdma_create_queue_ib(queue);
1093 	if (ret) {
1094 		pr_err("%s: creating RDMA queue failed (%d).\n",
1095 			__func__, ret);
1096 		ret = NVME_RDMA_CM_NO_RSC;
1097 		goto out_free_cmds;
1098 	}
1099 
1100 	return queue;
1101 
1102 out_free_cmds:
1103 	if (!ndev->srq) {
1104 		nvmet_rdma_free_cmds(queue->dev, queue->cmds,
1105 				queue->recv_queue_size,
1106 				!queue->host_qid);
1107 	}
1108 out_free_responses:
1109 	nvmet_rdma_free_rsps(queue);
1110 out_ida_remove:
1111 	ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
1112 out_destroy_sq:
1113 	nvmet_sq_destroy(&queue->nvme_sq);
1114 out_free_queue:
1115 	kfree(queue);
1116 out_reject:
1117 	nvmet_rdma_cm_reject(cm_id, ret);
1118 	return NULL;
1119 }
1120 
1121 static void nvmet_rdma_qp_event(struct ib_event *event, void *priv)
1122 {
1123 	struct nvmet_rdma_queue *queue = priv;
1124 
1125 	switch (event->event) {
1126 	case IB_EVENT_COMM_EST:
1127 		rdma_notify(queue->cm_id, event->event);
1128 		break;
1129 	default:
1130 		pr_err("received unrecognized IB QP event %d\n", event->event);
1131 		break;
1132 	}
1133 }
1134 
1135 static int nvmet_rdma_cm_accept(struct rdma_cm_id *cm_id,
1136 		struct nvmet_rdma_queue *queue,
1137 		struct rdma_conn_param *p)
1138 {
1139 	struct rdma_conn_param  param = { };
1140 	struct nvme_rdma_cm_rep priv = { };
1141 	int ret = -ENOMEM;
1142 
1143 	param.rnr_retry_count = 7;
1144 	param.flow_control = 1;
1145 	param.initiator_depth = min_t(u8, p->initiator_depth,
1146 		queue->dev->device->attrs.max_qp_init_rd_atom);
1147 	param.private_data = &priv;
1148 	param.private_data_len = sizeof(priv);
1149 	priv.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
1150 	priv.crqsize = cpu_to_le16(queue->recv_queue_size);
1151 
1152 	ret = rdma_accept(cm_id, &param);
1153 	if (ret)
1154 		pr_err("rdma_accept failed (error code = %d)\n", ret);
1155 
1156 	return ret;
1157 }
1158 
1159 static int nvmet_rdma_queue_connect(struct rdma_cm_id *cm_id,
1160 		struct rdma_cm_event *event)
1161 {
1162 	struct nvmet_rdma_device *ndev;
1163 	struct nvmet_rdma_queue *queue;
1164 	int ret = -EINVAL;
1165 
1166 	ndev = nvmet_rdma_find_get_device(cm_id);
1167 	if (!ndev) {
1168 		pr_err("no client data!\n");
1169 		nvmet_rdma_cm_reject(cm_id, NVME_RDMA_CM_NO_RSC);
1170 		return -ECONNREFUSED;
1171 	}
1172 
1173 	queue = nvmet_rdma_alloc_queue(ndev, cm_id, event);
1174 	if (!queue) {
1175 		ret = -ENOMEM;
1176 		goto put_device;
1177 	}
1178 	queue->port = cm_id->context;
1179 
1180 	ret = nvmet_rdma_cm_accept(cm_id, queue, &event->param.conn);
1181 	if (ret)
1182 		goto release_queue;
1183 
1184 	mutex_lock(&nvmet_rdma_queue_mutex);
1185 	list_add_tail(&queue->queue_list, &nvmet_rdma_queue_list);
1186 	mutex_unlock(&nvmet_rdma_queue_mutex);
1187 
1188 	return 0;
1189 
1190 release_queue:
1191 	nvmet_rdma_free_queue(queue);
1192 put_device:
1193 	kref_put(&ndev->ref, nvmet_rdma_free_dev);
1194 
1195 	return ret;
1196 }
1197 
1198 static void nvmet_rdma_queue_established(struct nvmet_rdma_queue *queue)
1199 {
1200 	unsigned long flags;
1201 
1202 	spin_lock_irqsave(&queue->state_lock, flags);
1203 	if (queue->state != NVMET_RDMA_Q_CONNECTING) {
1204 		pr_warn("trying to establish a connected queue\n");
1205 		goto out_unlock;
1206 	}
1207 	queue->state = NVMET_RDMA_Q_LIVE;
1208 
1209 	while (!list_empty(&queue->rsp_wait_list)) {
1210 		struct nvmet_rdma_rsp *cmd;
1211 
1212 		cmd = list_first_entry(&queue->rsp_wait_list,
1213 					struct nvmet_rdma_rsp, wait_list);
1214 		list_del(&cmd->wait_list);
1215 
1216 		spin_unlock_irqrestore(&queue->state_lock, flags);
1217 		nvmet_rdma_handle_command(queue, cmd);
1218 		spin_lock_irqsave(&queue->state_lock, flags);
1219 	}
1220 
1221 out_unlock:
1222 	spin_unlock_irqrestore(&queue->state_lock, flags);
1223 }
1224 
1225 static void __nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
1226 {
1227 	bool disconnect = false;
1228 	unsigned long flags;
1229 
1230 	pr_debug("cm_id= %p queue->state= %d\n", queue->cm_id, queue->state);
1231 
1232 	spin_lock_irqsave(&queue->state_lock, flags);
1233 	switch (queue->state) {
1234 	case NVMET_RDMA_Q_CONNECTING:
1235 	case NVMET_RDMA_Q_LIVE:
1236 		queue->state = NVMET_RDMA_Q_DISCONNECTING;
1237 	case NVMET_RDMA_IN_DEVICE_REMOVAL:
1238 		disconnect = true;
1239 		break;
1240 	case NVMET_RDMA_Q_DISCONNECTING:
1241 		break;
1242 	}
1243 	spin_unlock_irqrestore(&queue->state_lock, flags);
1244 
1245 	if (disconnect) {
1246 		rdma_disconnect(queue->cm_id);
1247 		ib_drain_qp(queue->cm_id->qp);
1248 		schedule_work(&queue->release_work);
1249 	}
1250 }
1251 
1252 static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
1253 {
1254 	bool disconnect = false;
1255 
1256 	mutex_lock(&nvmet_rdma_queue_mutex);
1257 	if (!list_empty(&queue->queue_list)) {
1258 		list_del_init(&queue->queue_list);
1259 		disconnect = true;
1260 	}
1261 	mutex_unlock(&nvmet_rdma_queue_mutex);
1262 
1263 	if (disconnect)
1264 		__nvmet_rdma_queue_disconnect(queue);
1265 }
1266 
1267 static void nvmet_rdma_queue_connect_fail(struct rdma_cm_id *cm_id,
1268 		struct nvmet_rdma_queue *queue)
1269 {
1270 	WARN_ON_ONCE(queue->state != NVMET_RDMA_Q_CONNECTING);
1271 
1272 	pr_err("failed to connect queue\n");
1273 	schedule_work(&queue->release_work);
1274 }
1275 
1276 /**
1277  * nvme_rdma_device_removal() - Handle RDMA device removal
1278  * @queue:      nvmet rdma queue (cm id qp_context)
1279  * @addr:	nvmet address (cm_id context)
1280  *
1281  * DEVICE_REMOVAL event notifies us that the RDMA device is about
1282  * to unplug so we should take care of destroying our RDMA resources.
1283  * This event will be generated for each allocated cm_id.
1284  *
1285  * Note that this event can be generated on a normal queue cm_id
1286  * and/or a device bound listener cm_id (where in this case
1287  * queue will be null).
1288  *
1289  * we claim ownership on destroying the cm_id. For queues we move
1290  * the queue state to NVMET_RDMA_IN_DEVICE_REMOVAL and for port
1291  * we nullify the priv to prevent double cm_id destruction and destroying
1292  * the cm_id implicitely by returning a non-zero rc to the callout.
1293  */
1294 static int nvmet_rdma_device_removal(struct rdma_cm_id *cm_id,
1295 		struct nvmet_rdma_queue *queue)
1296 {
1297 	unsigned long flags;
1298 
1299 	if (!queue) {
1300 		struct nvmet_port *port = cm_id->context;
1301 
1302 		/*
1303 		 * This is a listener cm_id. Make sure that
1304 		 * future remove_port won't invoke a double
1305 		 * cm_id destroy. use atomic xchg to make sure
1306 		 * we don't compete with remove_port.
1307 		 */
1308 		if (xchg(&port->priv, NULL) != cm_id)
1309 			return 0;
1310 	} else {
1311 		/*
1312 		 * This is a queue cm_id. Make sure that
1313 		 * release queue will not destroy the cm_id
1314 		 * and schedule all ctrl queues removal (only
1315 		 * if the queue is not disconnecting already).
1316 		 */
1317 		spin_lock_irqsave(&queue->state_lock, flags);
1318 		if (queue->state != NVMET_RDMA_Q_DISCONNECTING)
1319 			queue->state = NVMET_RDMA_IN_DEVICE_REMOVAL;
1320 		spin_unlock_irqrestore(&queue->state_lock, flags);
1321 		nvmet_rdma_queue_disconnect(queue);
1322 		flush_scheduled_work();
1323 	}
1324 
1325 	/*
1326 	 * We need to return 1 so that the core will destroy
1327 	 * it's own ID.  What a great API design..
1328 	 */
1329 	return 1;
1330 }
1331 
1332 static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
1333 		struct rdma_cm_event *event)
1334 {
1335 	struct nvmet_rdma_queue *queue = NULL;
1336 	int ret = 0;
1337 
1338 	if (cm_id->qp)
1339 		queue = cm_id->qp->qp_context;
1340 
1341 	pr_debug("%s (%d): status %d id %p\n",
1342 		rdma_event_msg(event->event), event->event,
1343 		event->status, cm_id);
1344 
1345 	switch (event->event) {
1346 	case RDMA_CM_EVENT_CONNECT_REQUEST:
1347 		ret = nvmet_rdma_queue_connect(cm_id, event);
1348 		break;
1349 	case RDMA_CM_EVENT_ESTABLISHED:
1350 		nvmet_rdma_queue_established(queue);
1351 		break;
1352 	case RDMA_CM_EVENT_ADDR_CHANGE:
1353 	case RDMA_CM_EVENT_DISCONNECTED:
1354 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1355 		nvmet_rdma_queue_disconnect(queue);
1356 		break;
1357 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
1358 		ret = nvmet_rdma_device_removal(cm_id, queue);
1359 		break;
1360 	case RDMA_CM_EVENT_REJECTED:
1361 	case RDMA_CM_EVENT_UNREACHABLE:
1362 	case RDMA_CM_EVENT_CONNECT_ERROR:
1363 		nvmet_rdma_queue_connect_fail(cm_id, queue);
1364 		break;
1365 	default:
1366 		pr_err("received unrecognized RDMA CM event %d\n",
1367 			event->event);
1368 		break;
1369 	}
1370 
1371 	return ret;
1372 }
1373 
1374 static void nvmet_rdma_delete_ctrl(struct nvmet_ctrl *ctrl)
1375 {
1376 	struct nvmet_rdma_queue *queue;
1377 
1378 restart:
1379 	mutex_lock(&nvmet_rdma_queue_mutex);
1380 	list_for_each_entry(queue, &nvmet_rdma_queue_list, queue_list) {
1381 		if (queue->nvme_sq.ctrl == ctrl) {
1382 			list_del_init(&queue->queue_list);
1383 			mutex_unlock(&nvmet_rdma_queue_mutex);
1384 
1385 			__nvmet_rdma_queue_disconnect(queue);
1386 			goto restart;
1387 		}
1388 	}
1389 	mutex_unlock(&nvmet_rdma_queue_mutex);
1390 }
1391 
1392 static int nvmet_rdma_add_port(struct nvmet_port *port)
1393 {
1394 	struct rdma_cm_id *cm_id;
1395 	struct sockaddr_in addr_in;
1396 	u16 port_in;
1397 	int ret;
1398 
1399 	switch (port->disc_addr.adrfam) {
1400 	case NVMF_ADDR_FAMILY_IP4:
1401 		break;
1402 	default:
1403 		pr_err("address family %d not supported\n",
1404 				port->disc_addr.adrfam);
1405 		return -EINVAL;
1406 	}
1407 
1408 	ret = kstrtou16(port->disc_addr.trsvcid, 0, &port_in);
1409 	if (ret)
1410 		return ret;
1411 
1412 	addr_in.sin_family = AF_INET;
1413 	addr_in.sin_addr.s_addr = in_aton(port->disc_addr.traddr);
1414 	addr_in.sin_port = htons(port_in);
1415 
1416 	cm_id = rdma_create_id(&init_net, nvmet_rdma_cm_handler, port,
1417 			RDMA_PS_TCP, IB_QPT_RC);
1418 	if (IS_ERR(cm_id)) {
1419 		pr_err("CM ID creation failed\n");
1420 		return PTR_ERR(cm_id);
1421 	}
1422 
1423 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&addr_in);
1424 	if (ret) {
1425 		pr_err("binding CM ID to %pISpc failed (%d)\n", &addr_in, ret);
1426 		goto out_destroy_id;
1427 	}
1428 
1429 	ret = rdma_listen(cm_id, 128);
1430 	if (ret) {
1431 		pr_err("listening to %pISpc failed (%d)\n", &addr_in, ret);
1432 		goto out_destroy_id;
1433 	}
1434 
1435 	pr_info("enabling port %d (%pISpc)\n",
1436 		le16_to_cpu(port->disc_addr.portid), &addr_in);
1437 	port->priv = cm_id;
1438 	return 0;
1439 
1440 out_destroy_id:
1441 	rdma_destroy_id(cm_id);
1442 	return ret;
1443 }
1444 
1445 static void nvmet_rdma_remove_port(struct nvmet_port *port)
1446 {
1447 	struct rdma_cm_id *cm_id = xchg(&port->priv, NULL);
1448 
1449 	if (cm_id)
1450 		rdma_destroy_id(cm_id);
1451 }
1452 
1453 static struct nvmet_fabrics_ops nvmet_rdma_ops = {
1454 	.owner			= THIS_MODULE,
1455 	.type			= NVMF_TRTYPE_RDMA,
1456 	.sqe_inline_size	= NVMET_RDMA_INLINE_DATA_SIZE,
1457 	.msdbd			= 1,
1458 	.has_keyed_sgls		= 1,
1459 	.add_port		= nvmet_rdma_add_port,
1460 	.remove_port		= nvmet_rdma_remove_port,
1461 	.queue_response		= nvmet_rdma_queue_response,
1462 	.delete_ctrl		= nvmet_rdma_delete_ctrl,
1463 };
1464 
1465 static int __init nvmet_rdma_init(void)
1466 {
1467 	return nvmet_register_transport(&nvmet_rdma_ops);
1468 }
1469 
1470 static void __exit nvmet_rdma_exit(void)
1471 {
1472 	struct nvmet_rdma_queue *queue;
1473 
1474 	nvmet_unregister_transport(&nvmet_rdma_ops);
1475 
1476 	flush_scheduled_work();
1477 
1478 	mutex_lock(&nvmet_rdma_queue_mutex);
1479 	while ((queue = list_first_entry_or_null(&nvmet_rdma_queue_list,
1480 			struct nvmet_rdma_queue, queue_list))) {
1481 		list_del_init(&queue->queue_list);
1482 
1483 		mutex_unlock(&nvmet_rdma_queue_mutex);
1484 		__nvmet_rdma_queue_disconnect(queue);
1485 		mutex_lock(&nvmet_rdma_queue_mutex);
1486 	}
1487 	mutex_unlock(&nvmet_rdma_queue_mutex);
1488 
1489 	flush_scheduled_work();
1490 	ida_destroy(&nvmet_rdma_queue_ida);
1491 }
1492 
1493 module_init(nvmet_rdma_init);
1494 module_exit(nvmet_rdma_exit);
1495 
1496 MODULE_LICENSE("GPL v2");
1497 MODULE_ALIAS("nvmet-transport-1"); /* 1 == NVMF_TRTYPE_RDMA */
1498