xref: /openbmc/linux/drivers/nvme/target/rdma.c (revision 95777591)
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 at least 1 page, up to 4 SGEs, and up to 16KB of inline data
37  */
38 #define NVMET_RDMA_DEFAULT_INLINE_DATA_SIZE	PAGE_SIZE
39 #define NVMET_RDMA_MAX_INLINE_SGE		4
40 #define NVMET_RDMA_MAX_INLINE_DATA_SIZE		max_t(int, SZ_16K, PAGE_SIZE)
41 
42 struct nvmet_rdma_cmd {
43 	struct ib_sge		sge[NVMET_RDMA_MAX_INLINE_SGE + 1];
44 	struct ib_cqe		cqe;
45 	struct ib_recv_wr	wr;
46 	struct scatterlist	inline_sg[NVMET_RDMA_MAX_INLINE_SGE];
47 	struct nvme_command     *nvme_cmd;
48 	struct nvmet_rdma_queue	*queue;
49 };
50 
51 enum {
52 	NVMET_RDMA_REQ_INLINE_DATA	= (1 << 0),
53 	NVMET_RDMA_REQ_INVALIDATE_RKEY	= (1 << 1),
54 };
55 
56 struct nvmet_rdma_rsp {
57 	struct ib_sge		send_sge;
58 	struct ib_cqe		send_cqe;
59 	struct ib_send_wr	send_wr;
60 
61 	struct nvmet_rdma_cmd	*cmd;
62 	struct nvmet_rdma_queue	*queue;
63 
64 	struct ib_cqe		read_cqe;
65 	struct rdma_rw_ctx	rw;
66 
67 	struct nvmet_req	req;
68 
69 	bool			allocated;
70 	u8			n_rdma;
71 	u32			flags;
72 	u32			invalidate_rkey;
73 
74 	struct list_head	wait_list;
75 	struct list_head	free_list;
76 };
77 
78 enum nvmet_rdma_queue_state {
79 	NVMET_RDMA_Q_CONNECTING,
80 	NVMET_RDMA_Q_LIVE,
81 	NVMET_RDMA_Q_DISCONNECTING,
82 };
83 
84 struct nvmet_rdma_queue {
85 	struct rdma_cm_id	*cm_id;
86 	struct nvmet_port	*port;
87 	struct ib_cq		*cq;
88 	atomic_t		sq_wr_avail;
89 	struct nvmet_rdma_device *dev;
90 	spinlock_t		state_lock;
91 	enum nvmet_rdma_queue_state state;
92 	struct nvmet_cq		nvme_cq;
93 	struct nvmet_sq		nvme_sq;
94 
95 	struct nvmet_rdma_rsp	*rsps;
96 	struct list_head	free_rsps;
97 	spinlock_t		rsps_lock;
98 	struct nvmet_rdma_cmd	*cmds;
99 
100 	struct work_struct	release_work;
101 	struct list_head	rsp_wait_list;
102 	struct list_head	rsp_wr_wait_list;
103 	spinlock_t		rsp_wr_wait_lock;
104 
105 	int			idx;
106 	int			host_qid;
107 	int			recv_queue_size;
108 	int			send_queue_size;
109 
110 	struct list_head	queue_list;
111 };
112 
113 struct nvmet_rdma_device {
114 	struct ib_device	*device;
115 	struct ib_pd		*pd;
116 	struct ib_srq		*srq;
117 	struct nvmet_rdma_cmd	*srq_cmds;
118 	size_t			srq_size;
119 	struct kref		ref;
120 	struct list_head	entry;
121 	int			inline_data_size;
122 	int			inline_page_count;
123 };
124 
125 static bool nvmet_rdma_use_srq;
126 module_param_named(use_srq, nvmet_rdma_use_srq, bool, 0444);
127 MODULE_PARM_DESC(use_srq, "Use shared receive queue.");
128 
129 static DEFINE_IDA(nvmet_rdma_queue_ida);
130 static LIST_HEAD(nvmet_rdma_queue_list);
131 static DEFINE_MUTEX(nvmet_rdma_queue_mutex);
132 
133 static LIST_HEAD(device_list);
134 static DEFINE_MUTEX(device_list_mutex);
135 
136 static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp);
137 static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc);
138 static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc);
139 static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc);
140 static void nvmet_rdma_qp_event(struct ib_event *event, void *priv);
141 static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue);
142 static void nvmet_rdma_free_rsp(struct nvmet_rdma_device *ndev,
143 				struct nvmet_rdma_rsp *r);
144 static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev,
145 				struct nvmet_rdma_rsp *r);
146 
147 static const struct nvmet_fabrics_ops nvmet_rdma_ops;
148 
149 static int num_pages(int len)
150 {
151 	return 1 + (((len - 1) & PAGE_MASK) >> PAGE_SHIFT);
152 }
153 
154 /* XXX: really should move to a generic header sooner or later.. */
155 static inline u32 get_unaligned_le24(const u8 *p)
156 {
157 	return (u32)p[0] | (u32)p[1] << 8 | (u32)p[2] << 16;
158 }
159 
160 static inline bool nvmet_rdma_need_data_in(struct nvmet_rdma_rsp *rsp)
161 {
162 	return nvme_is_write(rsp->req.cmd) &&
163 		rsp->req.transfer_len &&
164 		!(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
165 }
166 
167 static inline bool nvmet_rdma_need_data_out(struct nvmet_rdma_rsp *rsp)
168 {
169 	return !nvme_is_write(rsp->req.cmd) &&
170 		rsp->req.transfer_len &&
171 		!rsp->req.rsp->status &&
172 		!(rsp->flags & NVMET_RDMA_REQ_INLINE_DATA);
173 }
174 
175 static inline struct nvmet_rdma_rsp *
176 nvmet_rdma_get_rsp(struct nvmet_rdma_queue *queue)
177 {
178 	struct nvmet_rdma_rsp *rsp;
179 	unsigned long flags;
180 
181 	spin_lock_irqsave(&queue->rsps_lock, flags);
182 	rsp = list_first_entry_or_null(&queue->free_rsps,
183 				struct nvmet_rdma_rsp, free_list);
184 	if (likely(rsp))
185 		list_del(&rsp->free_list);
186 	spin_unlock_irqrestore(&queue->rsps_lock, flags);
187 
188 	if (unlikely(!rsp)) {
189 		int ret;
190 
191 		rsp = kzalloc(sizeof(*rsp), GFP_KERNEL);
192 		if (unlikely(!rsp))
193 			return NULL;
194 		ret = nvmet_rdma_alloc_rsp(queue->dev, rsp);
195 		if (unlikely(ret)) {
196 			kfree(rsp);
197 			return NULL;
198 		}
199 
200 		rsp->allocated = true;
201 	}
202 
203 	return rsp;
204 }
205 
206 static inline void
207 nvmet_rdma_put_rsp(struct nvmet_rdma_rsp *rsp)
208 {
209 	unsigned long flags;
210 
211 	if (unlikely(rsp->allocated)) {
212 		nvmet_rdma_free_rsp(rsp->queue->dev, rsp);
213 		kfree(rsp);
214 		return;
215 	}
216 
217 	spin_lock_irqsave(&rsp->queue->rsps_lock, flags);
218 	list_add_tail(&rsp->free_list, &rsp->queue->free_rsps);
219 	spin_unlock_irqrestore(&rsp->queue->rsps_lock, flags);
220 }
221 
222 static void nvmet_rdma_free_inline_pages(struct nvmet_rdma_device *ndev,
223 				struct nvmet_rdma_cmd *c)
224 {
225 	struct scatterlist *sg;
226 	struct ib_sge *sge;
227 	int i;
228 
229 	if (!ndev->inline_data_size)
230 		return;
231 
232 	sg = c->inline_sg;
233 	sge = &c->sge[1];
234 
235 	for (i = 0; i < ndev->inline_page_count; i++, sg++, sge++) {
236 		if (sge->length)
237 			ib_dma_unmap_page(ndev->device, sge->addr,
238 					sge->length, DMA_FROM_DEVICE);
239 		if (sg_page(sg))
240 			__free_page(sg_page(sg));
241 	}
242 }
243 
244 static int nvmet_rdma_alloc_inline_pages(struct nvmet_rdma_device *ndev,
245 				struct nvmet_rdma_cmd *c)
246 {
247 	struct scatterlist *sg;
248 	struct ib_sge *sge;
249 	struct page *pg;
250 	int len;
251 	int i;
252 
253 	if (!ndev->inline_data_size)
254 		return 0;
255 
256 	sg = c->inline_sg;
257 	sg_init_table(sg, ndev->inline_page_count);
258 	sge = &c->sge[1];
259 	len = ndev->inline_data_size;
260 
261 	for (i = 0; i < ndev->inline_page_count; i++, sg++, sge++) {
262 		pg = alloc_page(GFP_KERNEL);
263 		if (!pg)
264 			goto out_err;
265 		sg_assign_page(sg, pg);
266 		sge->addr = ib_dma_map_page(ndev->device,
267 			pg, 0, PAGE_SIZE, DMA_FROM_DEVICE);
268 		if (ib_dma_mapping_error(ndev->device, sge->addr))
269 			goto out_err;
270 		sge->length = min_t(int, len, PAGE_SIZE);
271 		sge->lkey = ndev->pd->local_dma_lkey;
272 		len -= sge->length;
273 	}
274 
275 	return 0;
276 out_err:
277 	for (; i >= 0; i--, sg--, sge--) {
278 		if (sge->length)
279 			ib_dma_unmap_page(ndev->device, sge->addr,
280 					sge->length, DMA_FROM_DEVICE);
281 		if (sg_page(sg))
282 			__free_page(sg_page(sg));
283 	}
284 	return -ENOMEM;
285 }
286 
287 static int nvmet_rdma_alloc_cmd(struct nvmet_rdma_device *ndev,
288 			struct nvmet_rdma_cmd *c, bool admin)
289 {
290 	/* NVMe command / RDMA RECV */
291 	c->nvme_cmd = kmalloc(sizeof(*c->nvme_cmd), GFP_KERNEL);
292 	if (!c->nvme_cmd)
293 		goto out;
294 
295 	c->sge[0].addr = ib_dma_map_single(ndev->device, c->nvme_cmd,
296 			sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
297 	if (ib_dma_mapping_error(ndev->device, c->sge[0].addr))
298 		goto out_free_cmd;
299 
300 	c->sge[0].length = sizeof(*c->nvme_cmd);
301 	c->sge[0].lkey = ndev->pd->local_dma_lkey;
302 
303 	if (!admin && nvmet_rdma_alloc_inline_pages(ndev, c))
304 		goto out_unmap_cmd;
305 
306 	c->cqe.done = nvmet_rdma_recv_done;
307 
308 	c->wr.wr_cqe = &c->cqe;
309 	c->wr.sg_list = c->sge;
310 	c->wr.num_sge = admin ? 1 : ndev->inline_page_count + 1;
311 
312 	return 0;
313 
314 out_unmap_cmd:
315 	ib_dma_unmap_single(ndev->device, c->sge[0].addr,
316 			sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
317 out_free_cmd:
318 	kfree(c->nvme_cmd);
319 
320 out:
321 	return -ENOMEM;
322 }
323 
324 static void nvmet_rdma_free_cmd(struct nvmet_rdma_device *ndev,
325 		struct nvmet_rdma_cmd *c, bool admin)
326 {
327 	if (!admin)
328 		nvmet_rdma_free_inline_pages(ndev, c);
329 	ib_dma_unmap_single(ndev->device, c->sge[0].addr,
330 				sizeof(*c->nvme_cmd), DMA_FROM_DEVICE);
331 	kfree(c->nvme_cmd);
332 }
333 
334 static struct nvmet_rdma_cmd *
335 nvmet_rdma_alloc_cmds(struct nvmet_rdma_device *ndev,
336 		int nr_cmds, bool admin)
337 {
338 	struct nvmet_rdma_cmd *cmds;
339 	int ret = -EINVAL, i;
340 
341 	cmds = kcalloc(nr_cmds, sizeof(struct nvmet_rdma_cmd), GFP_KERNEL);
342 	if (!cmds)
343 		goto out;
344 
345 	for (i = 0; i < nr_cmds; i++) {
346 		ret = nvmet_rdma_alloc_cmd(ndev, cmds + i, admin);
347 		if (ret)
348 			goto out_free;
349 	}
350 
351 	return cmds;
352 
353 out_free:
354 	while (--i >= 0)
355 		nvmet_rdma_free_cmd(ndev, cmds + i, admin);
356 	kfree(cmds);
357 out:
358 	return ERR_PTR(ret);
359 }
360 
361 static void nvmet_rdma_free_cmds(struct nvmet_rdma_device *ndev,
362 		struct nvmet_rdma_cmd *cmds, int nr_cmds, bool admin)
363 {
364 	int i;
365 
366 	for (i = 0; i < nr_cmds; i++)
367 		nvmet_rdma_free_cmd(ndev, cmds + i, admin);
368 	kfree(cmds);
369 }
370 
371 static int nvmet_rdma_alloc_rsp(struct nvmet_rdma_device *ndev,
372 		struct nvmet_rdma_rsp *r)
373 {
374 	/* NVMe CQE / RDMA SEND */
375 	r->req.rsp = kmalloc(sizeof(*r->req.rsp), GFP_KERNEL);
376 	if (!r->req.rsp)
377 		goto out;
378 
379 	r->send_sge.addr = ib_dma_map_single(ndev->device, r->req.rsp,
380 			sizeof(*r->req.rsp), DMA_TO_DEVICE);
381 	if (ib_dma_mapping_error(ndev->device, r->send_sge.addr))
382 		goto out_free_rsp;
383 
384 	r->send_sge.length = sizeof(*r->req.rsp);
385 	r->send_sge.lkey = ndev->pd->local_dma_lkey;
386 
387 	r->send_cqe.done = nvmet_rdma_send_done;
388 
389 	r->send_wr.wr_cqe = &r->send_cqe;
390 	r->send_wr.sg_list = &r->send_sge;
391 	r->send_wr.num_sge = 1;
392 	r->send_wr.send_flags = IB_SEND_SIGNALED;
393 
394 	/* Data In / RDMA READ */
395 	r->read_cqe.done = nvmet_rdma_read_data_done;
396 	return 0;
397 
398 out_free_rsp:
399 	kfree(r->req.rsp);
400 out:
401 	return -ENOMEM;
402 }
403 
404 static void nvmet_rdma_free_rsp(struct nvmet_rdma_device *ndev,
405 		struct nvmet_rdma_rsp *r)
406 {
407 	ib_dma_unmap_single(ndev->device, r->send_sge.addr,
408 				sizeof(*r->req.rsp), DMA_TO_DEVICE);
409 	kfree(r->req.rsp);
410 }
411 
412 static int
413 nvmet_rdma_alloc_rsps(struct nvmet_rdma_queue *queue)
414 {
415 	struct nvmet_rdma_device *ndev = queue->dev;
416 	int nr_rsps = queue->recv_queue_size * 2;
417 	int ret = -EINVAL, i;
418 
419 	queue->rsps = kcalloc(nr_rsps, sizeof(struct nvmet_rdma_rsp),
420 			GFP_KERNEL);
421 	if (!queue->rsps)
422 		goto out;
423 
424 	for (i = 0; i < nr_rsps; i++) {
425 		struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
426 
427 		ret = nvmet_rdma_alloc_rsp(ndev, rsp);
428 		if (ret)
429 			goto out_free;
430 
431 		list_add_tail(&rsp->free_list, &queue->free_rsps);
432 	}
433 
434 	return 0;
435 
436 out_free:
437 	while (--i >= 0) {
438 		struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
439 
440 		list_del(&rsp->free_list);
441 		nvmet_rdma_free_rsp(ndev, rsp);
442 	}
443 	kfree(queue->rsps);
444 out:
445 	return ret;
446 }
447 
448 static void nvmet_rdma_free_rsps(struct nvmet_rdma_queue *queue)
449 {
450 	struct nvmet_rdma_device *ndev = queue->dev;
451 	int i, nr_rsps = queue->recv_queue_size * 2;
452 
453 	for (i = 0; i < nr_rsps; i++) {
454 		struct nvmet_rdma_rsp *rsp = &queue->rsps[i];
455 
456 		list_del(&rsp->free_list);
457 		nvmet_rdma_free_rsp(ndev, rsp);
458 	}
459 	kfree(queue->rsps);
460 }
461 
462 static int nvmet_rdma_post_recv(struct nvmet_rdma_device *ndev,
463 		struct nvmet_rdma_cmd *cmd)
464 {
465 	int ret;
466 
467 	ib_dma_sync_single_for_device(ndev->device,
468 		cmd->sge[0].addr, cmd->sge[0].length,
469 		DMA_FROM_DEVICE);
470 
471 	if (ndev->srq)
472 		ret = ib_post_srq_recv(ndev->srq, &cmd->wr, NULL);
473 	else
474 		ret = ib_post_recv(cmd->queue->cm_id->qp, &cmd->wr, NULL);
475 
476 	if (unlikely(ret))
477 		pr_err("post_recv cmd failed\n");
478 
479 	return ret;
480 }
481 
482 static void nvmet_rdma_process_wr_wait_list(struct nvmet_rdma_queue *queue)
483 {
484 	spin_lock(&queue->rsp_wr_wait_lock);
485 	while (!list_empty(&queue->rsp_wr_wait_list)) {
486 		struct nvmet_rdma_rsp *rsp;
487 		bool ret;
488 
489 		rsp = list_entry(queue->rsp_wr_wait_list.next,
490 				struct nvmet_rdma_rsp, wait_list);
491 		list_del(&rsp->wait_list);
492 
493 		spin_unlock(&queue->rsp_wr_wait_lock);
494 		ret = nvmet_rdma_execute_command(rsp);
495 		spin_lock(&queue->rsp_wr_wait_lock);
496 
497 		if (!ret) {
498 			list_add(&rsp->wait_list, &queue->rsp_wr_wait_list);
499 			break;
500 		}
501 	}
502 	spin_unlock(&queue->rsp_wr_wait_lock);
503 }
504 
505 
506 static void nvmet_rdma_release_rsp(struct nvmet_rdma_rsp *rsp)
507 {
508 	struct nvmet_rdma_queue *queue = rsp->queue;
509 
510 	atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
511 
512 	if (rsp->n_rdma) {
513 		rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
514 				queue->cm_id->port_num, rsp->req.sg,
515 				rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
516 	}
517 
518 	if (rsp->req.sg != rsp->cmd->inline_sg)
519 		nvmet_req_free_sgl(&rsp->req);
520 
521 	if (unlikely(!list_empty_careful(&queue->rsp_wr_wait_list)))
522 		nvmet_rdma_process_wr_wait_list(queue);
523 
524 	nvmet_rdma_put_rsp(rsp);
525 }
526 
527 static void nvmet_rdma_error_comp(struct nvmet_rdma_queue *queue)
528 {
529 	if (queue->nvme_sq.ctrl) {
530 		nvmet_ctrl_fatal_error(queue->nvme_sq.ctrl);
531 	} else {
532 		/*
533 		 * we didn't setup the controller yet in case
534 		 * of admin connect error, just disconnect and
535 		 * cleanup the queue
536 		 */
537 		nvmet_rdma_queue_disconnect(queue);
538 	}
539 }
540 
541 static void nvmet_rdma_send_done(struct ib_cq *cq, struct ib_wc *wc)
542 {
543 	struct nvmet_rdma_rsp *rsp =
544 		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, send_cqe);
545 	struct nvmet_rdma_queue *queue = cq->cq_context;
546 
547 	nvmet_rdma_release_rsp(rsp);
548 
549 	if (unlikely(wc->status != IB_WC_SUCCESS &&
550 		     wc->status != IB_WC_WR_FLUSH_ERR)) {
551 		pr_err("SEND for CQE 0x%p failed with status %s (%d).\n",
552 			wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
553 		nvmet_rdma_error_comp(queue);
554 	}
555 }
556 
557 static void nvmet_rdma_queue_response(struct nvmet_req *req)
558 {
559 	struct nvmet_rdma_rsp *rsp =
560 		container_of(req, struct nvmet_rdma_rsp, req);
561 	struct rdma_cm_id *cm_id = rsp->queue->cm_id;
562 	struct ib_send_wr *first_wr;
563 
564 	if (rsp->flags & NVMET_RDMA_REQ_INVALIDATE_RKEY) {
565 		rsp->send_wr.opcode = IB_WR_SEND_WITH_INV;
566 		rsp->send_wr.ex.invalidate_rkey = rsp->invalidate_rkey;
567 	} else {
568 		rsp->send_wr.opcode = IB_WR_SEND;
569 	}
570 
571 	if (nvmet_rdma_need_data_out(rsp))
572 		first_wr = rdma_rw_ctx_wrs(&rsp->rw, cm_id->qp,
573 				cm_id->port_num, NULL, &rsp->send_wr);
574 	else
575 		first_wr = &rsp->send_wr;
576 
577 	nvmet_rdma_post_recv(rsp->queue->dev, rsp->cmd);
578 
579 	ib_dma_sync_single_for_device(rsp->queue->dev->device,
580 		rsp->send_sge.addr, rsp->send_sge.length,
581 		DMA_TO_DEVICE);
582 
583 	if (unlikely(ib_post_send(cm_id->qp, first_wr, NULL))) {
584 		pr_err("sending cmd response failed\n");
585 		nvmet_rdma_release_rsp(rsp);
586 	}
587 }
588 
589 static void nvmet_rdma_read_data_done(struct ib_cq *cq, struct ib_wc *wc)
590 {
591 	struct nvmet_rdma_rsp *rsp =
592 		container_of(wc->wr_cqe, struct nvmet_rdma_rsp, read_cqe);
593 	struct nvmet_rdma_queue *queue = cq->cq_context;
594 
595 	WARN_ON(rsp->n_rdma <= 0);
596 	atomic_add(rsp->n_rdma, &queue->sq_wr_avail);
597 	rdma_rw_ctx_destroy(&rsp->rw, queue->cm_id->qp,
598 			queue->cm_id->port_num, rsp->req.sg,
599 			rsp->req.sg_cnt, nvmet_data_dir(&rsp->req));
600 	rsp->n_rdma = 0;
601 
602 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
603 		nvmet_req_uninit(&rsp->req);
604 		nvmet_rdma_release_rsp(rsp);
605 		if (wc->status != IB_WC_WR_FLUSH_ERR) {
606 			pr_info("RDMA READ for CQE 0x%p failed with status %s (%d).\n",
607 				wc->wr_cqe, ib_wc_status_msg(wc->status), wc->status);
608 			nvmet_rdma_error_comp(queue);
609 		}
610 		return;
611 	}
612 
613 	nvmet_req_execute(&rsp->req);
614 }
615 
616 static void nvmet_rdma_use_inline_sg(struct nvmet_rdma_rsp *rsp, u32 len,
617 		u64 off)
618 {
619 	int sg_count = num_pages(len);
620 	struct scatterlist *sg;
621 	int i;
622 
623 	sg = rsp->cmd->inline_sg;
624 	for (i = 0; i < sg_count; i++, sg++) {
625 		if (i < sg_count - 1)
626 			sg_unmark_end(sg);
627 		else
628 			sg_mark_end(sg);
629 		sg->offset = off;
630 		sg->length = min_t(int, len, PAGE_SIZE - off);
631 		len -= sg->length;
632 		if (!i)
633 			off = 0;
634 	}
635 
636 	rsp->req.sg = rsp->cmd->inline_sg;
637 	rsp->req.sg_cnt = sg_count;
638 }
639 
640 static u16 nvmet_rdma_map_sgl_inline(struct nvmet_rdma_rsp *rsp)
641 {
642 	struct nvme_sgl_desc *sgl = &rsp->req.cmd->common.dptr.sgl;
643 	u64 off = le64_to_cpu(sgl->addr);
644 	u32 len = le32_to_cpu(sgl->length);
645 
646 	if (!nvme_is_write(rsp->req.cmd)) {
647 		rsp->req.error_loc =
648 			offsetof(struct nvme_common_command, opcode);
649 		return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
650 	}
651 
652 	if (off + len > rsp->queue->dev->inline_data_size) {
653 		pr_err("invalid inline data offset!\n");
654 		return NVME_SC_SGL_INVALID_OFFSET | NVME_SC_DNR;
655 	}
656 
657 	/* no data command? */
658 	if (!len)
659 		return 0;
660 
661 	nvmet_rdma_use_inline_sg(rsp, len, off);
662 	rsp->flags |= NVMET_RDMA_REQ_INLINE_DATA;
663 	rsp->req.transfer_len += len;
664 	return 0;
665 }
666 
667 static u16 nvmet_rdma_map_sgl_keyed(struct nvmet_rdma_rsp *rsp,
668 		struct nvme_keyed_sgl_desc *sgl, bool invalidate)
669 {
670 	struct rdma_cm_id *cm_id = rsp->queue->cm_id;
671 	u64 addr = le64_to_cpu(sgl->addr);
672 	u32 key = get_unaligned_le32(sgl->key);
673 	int ret;
674 
675 	rsp->req.transfer_len = get_unaligned_le24(sgl->length);
676 
677 	/* no data command? */
678 	if (!rsp->req.transfer_len)
679 		return 0;
680 
681 	ret = nvmet_req_alloc_sgl(&rsp->req);
682 	if (ret < 0)
683 		goto error_out;
684 
685 	ret = rdma_rw_ctx_init(&rsp->rw, cm_id->qp, cm_id->port_num,
686 			rsp->req.sg, rsp->req.sg_cnt, 0, addr, key,
687 			nvmet_data_dir(&rsp->req));
688 	if (ret < 0)
689 		goto error_out;
690 	rsp->n_rdma += ret;
691 
692 	if (invalidate) {
693 		rsp->invalidate_rkey = key;
694 		rsp->flags |= NVMET_RDMA_REQ_INVALIDATE_RKEY;
695 	}
696 
697 	return 0;
698 
699 error_out:
700 	rsp->req.transfer_len = 0;
701 	return NVME_SC_INTERNAL;
702 }
703 
704 static u16 nvmet_rdma_map_sgl(struct nvmet_rdma_rsp *rsp)
705 {
706 	struct nvme_keyed_sgl_desc *sgl = &rsp->req.cmd->common.dptr.ksgl;
707 
708 	switch (sgl->type >> 4) {
709 	case NVME_SGL_FMT_DATA_DESC:
710 		switch (sgl->type & 0xf) {
711 		case NVME_SGL_FMT_OFFSET:
712 			return nvmet_rdma_map_sgl_inline(rsp);
713 		default:
714 			pr_err("invalid SGL subtype: %#x\n", sgl->type);
715 			rsp->req.error_loc =
716 				offsetof(struct nvme_common_command, dptr);
717 			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
718 		}
719 	case NVME_KEY_SGL_FMT_DATA_DESC:
720 		switch (sgl->type & 0xf) {
721 		case NVME_SGL_FMT_ADDRESS | NVME_SGL_FMT_INVALIDATE:
722 			return nvmet_rdma_map_sgl_keyed(rsp, sgl, true);
723 		case NVME_SGL_FMT_ADDRESS:
724 			return nvmet_rdma_map_sgl_keyed(rsp, sgl, false);
725 		default:
726 			pr_err("invalid SGL subtype: %#x\n", sgl->type);
727 			rsp->req.error_loc =
728 				offsetof(struct nvme_common_command, dptr);
729 			return NVME_SC_INVALID_FIELD | NVME_SC_DNR;
730 		}
731 	default:
732 		pr_err("invalid SGL type: %#x\n", sgl->type);
733 		rsp->req.error_loc = offsetof(struct nvme_common_command, dptr);
734 		return NVME_SC_SGL_INVALID_TYPE | NVME_SC_DNR;
735 	}
736 }
737 
738 static bool nvmet_rdma_execute_command(struct nvmet_rdma_rsp *rsp)
739 {
740 	struct nvmet_rdma_queue *queue = rsp->queue;
741 
742 	if (unlikely(atomic_sub_return(1 + rsp->n_rdma,
743 			&queue->sq_wr_avail) < 0)) {
744 		pr_debug("IB send queue full (needed %d): queue %u cntlid %u\n",
745 				1 + rsp->n_rdma, queue->idx,
746 				queue->nvme_sq.ctrl->cntlid);
747 		atomic_add(1 + rsp->n_rdma, &queue->sq_wr_avail);
748 		return false;
749 	}
750 
751 	if (nvmet_rdma_need_data_in(rsp)) {
752 		if (rdma_rw_ctx_post(&rsp->rw, queue->cm_id->qp,
753 				queue->cm_id->port_num, &rsp->read_cqe, NULL))
754 			nvmet_req_complete(&rsp->req, NVME_SC_DATA_XFER_ERROR);
755 	} else {
756 		nvmet_req_execute(&rsp->req);
757 	}
758 
759 	return true;
760 }
761 
762 static void nvmet_rdma_handle_command(struct nvmet_rdma_queue *queue,
763 		struct nvmet_rdma_rsp *cmd)
764 {
765 	u16 status;
766 
767 	ib_dma_sync_single_for_cpu(queue->dev->device,
768 		cmd->cmd->sge[0].addr, cmd->cmd->sge[0].length,
769 		DMA_FROM_DEVICE);
770 	ib_dma_sync_single_for_cpu(queue->dev->device,
771 		cmd->send_sge.addr, cmd->send_sge.length,
772 		DMA_TO_DEVICE);
773 
774 	cmd->req.p2p_client = &queue->dev->device->dev;
775 
776 	if (!nvmet_req_init(&cmd->req, &queue->nvme_cq,
777 			&queue->nvme_sq, &nvmet_rdma_ops))
778 		return;
779 
780 	status = nvmet_rdma_map_sgl(cmd);
781 	if (status)
782 		goto out_err;
783 
784 	if (unlikely(!nvmet_rdma_execute_command(cmd))) {
785 		spin_lock(&queue->rsp_wr_wait_lock);
786 		list_add_tail(&cmd->wait_list, &queue->rsp_wr_wait_list);
787 		spin_unlock(&queue->rsp_wr_wait_lock);
788 	}
789 
790 	return;
791 
792 out_err:
793 	nvmet_req_complete(&cmd->req, status);
794 }
795 
796 static void nvmet_rdma_recv_done(struct ib_cq *cq, struct ib_wc *wc)
797 {
798 	struct nvmet_rdma_cmd *cmd =
799 		container_of(wc->wr_cqe, struct nvmet_rdma_cmd, cqe);
800 	struct nvmet_rdma_queue *queue = cq->cq_context;
801 	struct nvmet_rdma_rsp *rsp;
802 
803 	if (unlikely(wc->status != IB_WC_SUCCESS)) {
804 		if (wc->status != IB_WC_WR_FLUSH_ERR) {
805 			pr_err("RECV for CQE 0x%p failed with status %s (%d)\n",
806 				wc->wr_cqe, ib_wc_status_msg(wc->status),
807 				wc->status);
808 			nvmet_rdma_error_comp(queue);
809 		}
810 		return;
811 	}
812 
813 	if (unlikely(wc->byte_len < sizeof(struct nvme_command))) {
814 		pr_err("Ctrl Fatal Error: capsule size less than 64 bytes\n");
815 		nvmet_rdma_error_comp(queue);
816 		return;
817 	}
818 
819 	cmd->queue = queue;
820 	rsp = nvmet_rdma_get_rsp(queue);
821 	if (unlikely(!rsp)) {
822 		/*
823 		 * we get here only under memory pressure,
824 		 * silently drop and have the host retry
825 		 * as we can't even fail it.
826 		 */
827 		nvmet_rdma_post_recv(queue->dev, cmd);
828 		return;
829 	}
830 	rsp->queue = queue;
831 	rsp->cmd = cmd;
832 	rsp->flags = 0;
833 	rsp->req.cmd = cmd->nvme_cmd;
834 	rsp->req.port = queue->port;
835 	rsp->n_rdma = 0;
836 
837 	if (unlikely(queue->state != NVMET_RDMA_Q_LIVE)) {
838 		unsigned long flags;
839 
840 		spin_lock_irqsave(&queue->state_lock, flags);
841 		if (queue->state == NVMET_RDMA_Q_CONNECTING)
842 			list_add_tail(&rsp->wait_list, &queue->rsp_wait_list);
843 		else
844 			nvmet_rdma_put_rsp(rsp);
845 		spin_unlock_irqrestore(&queue->state_lock, flags);
846 		return;
847 	}
848 
849 	nvmet_rdma_handle_command(queue, rsp);
850 }
851 
852 static void nvmet_rdma_destroy_srq(struct nvmet_rdma_device *ndev)
853 {
854 	if (!ndev->srq)
855 		return;
856 
857 	nvmet_rdma_free_cmds(ndev, ndev->srq_cmds, ndev->srq_size, false);
858 	ib_destroy_srq(ndev->srq);
859 }
860 
861 static int nvmet_rdma_init_srq(struct nvmet_rdma_device *ndev)
862 {
863 	struct ib_srq_init_attr srq_attr = { NULL, };
864 	struct ib_srq *srq;
865 	size_t srq_size;
866 	int ret, i;
867 
868 	srq_size = 4095;	/* XXX: tune */
869 
870 	srq_attr.attr.max_wr = srq_size;
871 	srq_attr.attr.max_sge = 1 + ndev->inline_page_count;
872 	srq_attr.attr.srq_limit = 0;
873 	srq_attr.srq_type = IB_SRQT_BASIC;
874 	srq = ib_create_srq(ndev->pd, &srq_attr);
875 	if (IS_ERR(srq)) {
876 		/*
877 		 * If SRQs aren't supported we just go ahead and use normal
878 		 * non-shared receive queues.
879 		 */
880 		pr_info("SRQ requested but not supported.\n");
881 		return 0;
882 	}
883 
884 	ndev->srq_cmds = nvmet_rdma_alloc_cmds(ndev, srq_size, false);
885 	if (IS_ERR(ndev->srq_cmds)) {
886 		ret = PTR_ERR(ndev->srq_cmds);
887 		goto out_destroy_srq;
888 	}
889 
890 	ndev->srq = srq;
891 	ndev->srq_size = srq_size;
892 
893 	for (i = 0; i < srq_size; i++) {
894 		ret = nvmet_rdma_post_recv(ndev, &ndev->srq_cmds[i]);
895 		if (ret)
896 			goto out_free_cmds;
897 	}
898 
899 	return 0;
900 
901 out_free_cmds:
902 	nvmet_rdma_free_cmds(ndev, ndev->srq_cmds, ndev->srq_size, false);
903 out_destroy_srq:
904 	ib_destroy_srq(srq);
905 	return ret;
906 }
907 
908 static void nvmet_rdma_free_dev(struct kref *ref)
909 {
910 	struct nvmet_rdma_device *ndev =
911 		container_of(ref, struct nvmet_rdma_device, ref);
912 
913 	mutex_lock(&device_list_mutex);
914 	list_del(&ndev->entry);
915 	mutex_unlock(&device_list_mutex);
916 
917 	nvmet_rdma_destroy_srq(ndev);
918 	ib_dealloc_pd(ndev->pd);
919 
920 	kfree(ndev);
921 }
922 
923 static struct nvmet_rdma_device *
924 nvmet_rdma_find_get_device(struct rdma_cm_id *cm_id)
925 {
926 	struct nvmet_port *port = cm_id->context;
927 	struct nvmet_rdma_device *ndev;
928 	int inline_page_count;
929 	int inline_sge_count;
930 	int ret;
931 
932 	mutex_lock(&device_list_mutex);
933 	list_for_each_entry(ndev, &device_list, entry) {
934 		if (ndev->device->node_guid == cm_id->device->node_guid &&
935 		    kref_get_unless_zero(&ndev->ref))
936 			goto out_unlock;
937 	}
938 
939 	ndev = kzalloc(sizeof(*ndev), GFP_KERNEL);
940 	if (!ndev)
941 		goto out_err;
942 
943 	inline_page_count = num_pages(port->inline_data_size);
944 	inline_sge_count = max(cm_id->device->attrs.max_sge_rd,
945 				cm_id->device->attrs.max_recv_sge) - 1;
946 	if (inline_page_count > inline_sge_count) {
947 		pr_warn("inline_data_size %d cannot be supported by device %s. Reducing to %lu.\n",
948 			port->inline_data_size, cm_id->device->name,
949 			inline_sge_count * PAGE_SIZE);
950 		port->inline_data_size = inline_sge_count * PAGE_SIZE;
951 		inline_page_count = inline_sge_count;
952 	}
953 	ndev->inline_data_size = port->inline_data_size;
954 	ndev->inline_page_count = inline_page_count;
955 	ndev->device = cm_id->device;
956 	kref_init(&ndev->ref);
957 
958 	ndev->pd = ib_alloc_pd(ndev->device, 0);
959 	if (IS_ERR(ndev->pd))
960 		goto out_free_dev;
961 
962 	if (nvmet_rdma_use_srq) {
963 		ret = nvmet_rdma_init_srq(ndev);
964 		if (ret)
965 			goto out_free_pd;
966 	}
967 
968 	list_add(&ndev->entry, &device_list);
969 out_unlock:
970 	mutex_unlock(&device_list_mutex);
971 	pr_debug("added %s.\n", ndev->device->name);
972 	return ndev;
973 
974 out_free_pd:
975 	ib_dealloc_pd(ndev->pd);
976 out_free_dev:
977 	kfree(ndev);
978 out_err:
979 	mutex_unlock(&device_list_mutex);
980 	return NULL;
981 }
982 
983 static int nvmet_rdma_create_queue_ib(struct nvmet_rdma_queue *queue)
984 {
985 	struct ib_qp_init_attr qp_attr;
986 	struct nvmet_rdma_device *ndev = queue->dev;
987 	int comp_vector, nr_cqe, ret, i;
988 
989 	/*
990 	 * Spread the io queues across completion vectors,
991 	 * but still keep all admin queues on vector 0.
992 	 */
993 	comp_vector = !queue->host_qid ? 0 :
994 		queue->idx % ndev->device->num_comp_vectors;
995 
996 	/*
997 	 * Reserve CQ slots for RECV + RDMA_READ/RDMA_WRITE + RDMA_SEND.
998 	 */
999 	nr_cqe = queue->recv_queue_size + 2 * queue->send_queue_size;
1000 
1001 	queue->cq = ib_alloc_cq(ndev->device, queue,
1002 			nr_cqe + 1, comp_vector,
1003 			IB_POLL_WORKQUEUE);
1004 	if (IS_ERR(queue->cq)) {
1005 		ret = PTR_ERR(queue->cq);
1006 		pr_err("failed to create CQ cqe= %d ret= %d\n",
1007 		       nr_cqe + 1, ret);
1008 		goto out;
1009 	}
1010 
1011 	memset(&qp_attr, 0, sizeof(qp_attr));
1012 	qp_attr.qp_context = queue;
1013 	qp_attr.event_handler = nvmet_rdma_qp_event;
1014 	qp_attr.send_cq = queue->cq;
1015 	qp_attr.recv_cq = queue->cq;
1016 	qp_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
1017 	qp_attr.qp_type = IB_QPT_RC;
1018 	/* +1 for drain */
1019 	qp_attr.cap.max_send_wr = queue->send_queue_size + 1;
1020 	qp_attr.cap.max_rdma_ctxs = queue->send_queue_size;
1021 	qp_attr.cap.max_send_sge = max(ndev->device->attrs.max_sge_rd,
1022 					ndev->device->attrs.max_send_sge);
1023 
1024 	if (ndev->srq) {
1025 		qp_attr.srq = ndev->srq;
1026 	} else {
1027 		/* +1 for drain */
1028 		qp_attr.cap.max_recv_wr = 1 + queue->recv_queue_size;
1029 		qp_attr.cap.max_recv_sge = 1 + ndev->inline_page_count;
1030 	}
1031 
1032 	ret = rdma_create_qp(queue->cm_id, ndev->pd, &qp_attr);
1033 	if (ret) {
1034 		pr_err("failed to create_qp ret= %d\n", ret);
1035 		goto err_destroy_cq;
1036 	}
1037 
1038 	atomic_set(&queue->sq_wr_avail, qp_attr.cap.max_send_wr);
1039 
1040 	pr_debug("%s: max_cqe= %d max_sge= %d sq_size = %d cm_id= %p\n",
1041 		 __func__, queue->cq->cqe, qp_attr.cap.max_send_sge,
1042 		 qp_attr.cap.max_send_wr, queue->cm_id);
1043 
1044 	if (!ndev->srq) {
1045 		for (i = 0; i < queue->recv_queue_size; i++) {
1046 			queue->cmds[i].queue = queue;
1047 			ret = nvmet_rdma_post_recv(ndev, &queue->cmds[i]);
1048 			if (ret)
1049 				goto err_destroy_qp;
1050 		}
1051 	}
1052 
1053 out:
1054 	return ret;
1055 
1056 err_destroy_qp:
1057 	rdma_destroy_qp(queue->cm_id);
1058 err_destroy_cq:
1059 	ib_free_cq(queue->cq);
1060 	goto out;
1061 }
1062 
1063 static void nvmet_rdma_destroy_queue_ib(struct nvmet_rdma_queue *queue)
1064 {
1065 	struct ib_qp *qp = queue->cm_id->qp;
1066 
1067 	ib_drain_qp(qp);
1068 	rdma_destroy_id(queue->cm_id);
1069 	ib_destroy_qp(qp);
1070 	ib_free_cq(queue->cq);
1071 }
1072 
1073 static void nvmet_rdma_free_queue(struct nvmet_rdma_queue *queue)
1074 {
1075 	pr_debug("freeing queue %d\n", queue->idx);
1076 
1077 	nvmet_sq_destroy(&queue->nvme_sq);
1078 
1079 	nvmet_rdma_destroy_queue_ib(queue);
1080 	if (!queue->dev->srq) {
1081 		nvmet_rdma_free_cmds(queue->dev, queue->cmds,
1082 				queue->recv_queue_size,
1083 				!queue->host_qid);
1084 	}
1085 	nvmet_rdma_free_rsps(queue);
1086 	ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
1087 	kfree(queue);
1088 }
1089 
1090 static void nvmet_rdma_release_queue_work(struct work_struct *w)
1091 {
1092 	struct nvmet_rdma_queue *queue =
1093 		container_of(w, struct nvmet_rdma_queue, release_work);
1094 	struct nvmet_rdma_device *dev = queue->dev;
1095 
1096 	nvmet_rdma_free_queue(queue);
1097 
1098 	kref_put(&dev->ref, nvmet_rdma_free_dev);
1099 }
1100 
1101 static int
1102 nvmet_rdma_parse_cm_connect_req(struct rdma_conn_param *conn,
1103 				struct nvmet_rdma_queue *queue)
1104 {
1105 	struct nvme_rdma_cm_req *req;
1106 
1107 	req = (struct nvme_rdma_cm_req *)conn->private_data;
1108 	if (!req || conn->private_data_len == 0)
1109 		return NVME_RDMA_CM_INVALID_LEN;
1110 
1111 	if (le16_to_cpu(req->recfmt) != NVME_RDMA_CM_FMT_1_0)
1112 		return NVME_RDMA_CM_INVALID_RECFMT;
1113 
1114 	queue->host_qid = le16_to_cpu(req->qid);
1115 
1116 	/*
1117 	 * req->hsqsize corresponds to our recv queue size plus 1
1118 	 * req->hrqsize corresponds to our send queue size
1119 	 */
1120 	queue->recv_queue_size = le16_to_cpu(req->hsqsize) + 1;
1121 	queue->send_queue_size = le16_to_cpu(req->hrqsize);
1122 
1123 	if (!queue->host_qid && queue->recv_queue_size > NVME_AQ_DEPTH)
1124 		return NVME_RDMA_CM_INVALID_HSQSIZE;
1125 
1126 	/* XXX: Should we enforce some kind of max for IO queues? */
1127 
1128 	return 0;
1129 }
1130 
1131 static int nvmet_rdma_cm_reject(struct rdma_cm_id *cm_id,
1132 				enum nvme_rdma_cm_status status)
1133 {
1134 	struct nvme_rdma_cm_rej rej;
1135 
1136 	pr_debug("rejecting connect request: status %d (%s)\n",
1137 		 status, nvme_rdma_cm_msg(status));
1138 
1139 	rej.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
1140 	rej.sts = cpu_to_le16(status);
1141 
1142 	return rdma_reject(cm_id, (void *)&rej, sizeof(rej));
1143 }
1144 
1145 static struct nvmet_rdma_queue *
1146 nvmet_rdma_alloc_queue(struct nvmet_rdma_device *ndev,
1147 		struct rdma_cm_id *cm_id,
1148 		struct rdma_cm_event *event)
1149 {
1150 	struct nvmet_rdma_queue *queue;
1151 	int ret;
1152 
1153 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
1154 	if (!queue) {
1155 		ret = NVME_RDMA_CM_NO_RSC;
1156 		goto out_reject;
1157 	}
1158 
1159 	ret = nvmet_sq_init(&queue->nvme_sq);
1160 	if (ret) {
1161 		ret = NVME_RDMA_CM_NO_RSC;
1162 		goto out_free_queue;
1163 	}
1164 
1165 	ret = nvmet_rdma_parse_cm_connect_req(&event->param.conn, queue);
1166 	if (ret)
1167 		goto out_destroy_sq;
1168 
1169 	/*
1170 	 * Schedules the actual release because calling rdma_destroy_id from
1171 	 * inside a CM callback would trigger a deadlock. (great API design..)
1172 	 */
1173 	INIT_WORK(&queue->release_work, nvmet_rdma_release_queue_work);
1174 	queue->dev = ndev;
1175 	queue->cm_id = cm_id;
1176 
1177 	spin_lock_init(&queue->state_lock);
1178 	queue->state = NVMET_RDMA_Q_CONNECTING;
1179 	INIT_LIST_HEAD(&queue->rsp_wait_list);
1180 	INIT_LIST_HEAD(&queue->rsp_wr_wait_list);
1181 	spin_lock_init(&queue->rsp_wr_wait_lock);
1182 	INIT_LIST_HEAD(&queue->free_rsps);
1183 	spin_lock_init(&queue->rsps_lock);
1184 	INIT_LIST_HEAD(&queue->queue_list);
1185 
1186 	queue->idx = ida_simple_get(&nvmet_rdma_queue_ida, 0, 0, GFP_KERNEL);
1187 	if (queue->idx < 0) {
1188 		ret = NVME_RDMA_CM_NO_RSC;
1189 		goto out_destroy_sq;
1190 	}
1191 
1192 	ret = nvmet_rdma_alloc_rsps(queue);
1193 	if (ret) {
1194 		ret = NVME_RDMA_CM_NO_RSC;
1195 		goto out_ida_remove;
1196 	}
1197 
1198 	if (!ndev->srq) {
1199 		queue->cmds = nvmet_rdma_alloc_cmds(ndev,
1200 				queue->recv_queue_size,
1201 				!queue->host_qid);
1202 		if (IS_ERR(queue->cmds)) {
1203 			ret = NVME_RDMA_CM_NO_RSC;
1204 			goto out_free_responses;
1205 		}
1206 	}
1207 
1208 	ret = nvmet_rdma_create_queue_ib(queue);
1209 	if (ret) {
1210 		pr_err("%s: creating RDMA queue failed (%d).\n",
1211 			__func__, ret);
1212 		ret = NVME_RDMA_CM_NO_RSC;
1213 		goto out_free_cmds;
1214 	}
1215 
1216 	return queue;
1217 
1218 out_free_cmds:
1219 	if (!ndev->srq) {
1220 		nvmet_rdma_free_cmds(queue->dev, queue->cmds,
1221 				queue->recv_queue_size,
1222 				!queue->host_qid);
1223 	}
1224 out_free_responses:
1225 	nvmet_rdma_free_rsps(queue);
1226 out_ida_remove:
1227 	ida_simple_remove(&nvmet_rdma_queue_ida, queue->idx);
1228 out_destroy_sq:
1229 	nvmet_sq_destroy(&queue->nvme_sq);
1230 out_free_queue:
1231 	kfree(queue);
1232 out_reject:
1233 	nvmet_rdma_cm_reject(cm_id, ret);
1234 	return NULL;
1235 }
1236 
1237 static void nvmet_rdma_qp_event(struct ib_event *event, void *priv)
1238 {
1239 	struct nvmet_rdma_queue *queue = priv;
1240 
1241 	switch (event->event) {
1242 	case IB_EVENT_COMM_EST:
1243 		rdma_notify(queue->cm_id, event->event);
1244 		break;
1245 	default:
1246 		pr_err("received IB QP event: %s (%d)\n",
1247 		       ib_event_msg(event->event), event->event);
1248 		break;
1249 	}
1250 }
1251 
1252 static int nvmet_rdma_cm_accept(struct rdma_cm_id *cm_id,
1253 		struct nvmet_rdma_queue *queue,
1254 		struct rdma_conn_param *p)
1255 {
1256 	struct rdma_conn_param  param = { };
1257 	struct nvme_rdma_cm_rep priv = { };
1258 	int ret = -ENOMEM;
1259 
1260 	param.rnr_retry_count = 7;
1261 	param.flow_control = 1;
1262 	param.initiator_depth = min_t(u8, p->initiator_depth,
1263 		queue->dev->device->attrs.max_qp_init_rd_atom);
1264 	param.private_data = &priv;
1265 	param.private_data_len = sizeof(priv);
1266 	priv.recfmt = cpu_to_le16(NVME_RDMA_CM_FMT_1_0);
1267 	priv.crqsize = cpu_to_le16(queue->recv_queue_size);
1268 
1269 	ret = rdma_accept(cm_id, &param);
1270 	if (ret)
1271 		pr_err("rdma_accept failed (error code = %d)\n", ret);
1272 
1273 	return ret;
1274 }
1275 
1276 static int nvmet_rdma_queue_connect(struct rdma_cm_id *cm_id,
1277 		struct rdma_cm_event *event)
1278 {
1279 	struct nvmet_rdma_device *ndev;
1280 	struct nvmet_rdma_queue *queue;
1281 	int ret = -EINVAL;
1282 
1283 	ndev = nvmet_rdma_find_get_device(cm_id);
1284 	if (!ndev) {
1285 		nvmet_rdma_cm_reject(cm_id, NVME_RDMA_CM_NO_RSC);
1286 		return -ECONNREFUSED;
1287 	}
1288 
1289 	queue = nvmet_rdma_alloc_queue(ndev, cm_id, event);
1290 	if (!queue) {
1291 		ret = -ENOMEM;
1292 		goto put_device;
1293 	}
1294 	queue->port = cm_id->context;
1295 
1296 	if (queue->host_qid == 0) {
1297 		/* Let inflight controller teardown complete */
1298 		flush_scheduled_work();
1299 	}
1300 
1301 	ret = nvmet_rdma_cm_accept(cm_id, queue, &event->param.conn);
1302 	if (ret) {
1303 		schedule_work(&queue->release_work);
1304 		/* Destroying rdma_cm id is not needed here */
1305 		return 0;
1306 	}
1307 
1308 	mutex_lock(&nvmet_rdma_queue_mutex);
1309 	list_add_tail(&queue->queue_list, &nvmet_rdma_queue_list);
1310 	mutex_unlock(&nvmet_rdma_queue_mutex);
1311 
1312 	return 0;
1313 
1314 put_device:
1315 	kref_put(&ndev->ref, nvmet_rdma_free_dev);
1316 
1317 	return ret;
1318 }
1319 
1320 static void nvmet_rdma_queue_established(struct nvmet_rdma_queue *queue)
1321 {
1322 	unsigned long flags;
1323 
1324 	spin_lock_irqsave(&queue->state_lock, flags);
1325 	if (queue->state != NVMET_RDMA_Q_CONNECTING) {
1326 		pr_warn("trying to establish a connected queue\n");
1327 		goto out_unlock;
1328 	}
1329 	queue->state = NVMET_RDMA_Q_LIVE;
1330 
1331 	while (!list_empty(&queue->rsp_wait_list)) {
1332 		struct nvmet_rdma_rsp *cmd;
1333 
1334 		cmd = list_first_entry(&queue->rsp_wait_list,
1335 					struct nvmet_rdma_rsp, wait_list);
1336 		list_del(&cmd->wait_list);
1337 
1338 		spin_unlock_irqrestore(&queue->state_lock, flags);
1339 		nvmet_rdma_handle_command(queue, cmd);
1340 		spin_lock_irqsave(&queue->state_lock, flags);
1341 	}
1342 
1343 out_unlock:
1344 	spin_unlock_irqrestore(&queue->state_lock, flags);
1345 }
1346 
1347 static void __nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
1348 {
1349 	bool disconnect = false;
1350 	unsigned long flags;
1351 
1352 	pr_debug("cm_id= %p queue->state= %d\n", queue->cm_id, queue->state);
1353 
1354 	spin_lock_irqsave(&queue->state_lock, flags);
1355 	switch (queue->state) {
1356 	case NVMET_RDMA_Q_CONNECTING:
1357 	case NVMET_RDMA_Q_LIVE:
1358 		queue->state = NVMET_RDMA_Q_DISCONNECTING;
1359 		disconnect = true;
1360 		break;
1361 	case NVMET_RDMA_Q_DISCONNECTING:
1362 		break;
1363 	}
1364 	spin_unlock_irqrestore(&queue->state_lock, flags);
1365 
1366 	if (disconnect) {
1367 		rdma_disconnect(queue->cm_id);
1368 		schedule_work(&queue->release_work);
1369 	}
1370 }
1371 
1372 static void nvmet_rdma_queue_disconnect(struct nvmet_rdma_queue *queue)
1373 {
1374 	bool disconnect = false;
1375 
1376 	mutex_lock(&nvmet_rdma_queue_mutex);
1377 	if (!list_empty(&queue->queue_list)) {
1378 		list_del_init(&queue->queue_list);
1379 		disconnect = true;
1380 	}
1381 	mutex_unlock(&nvmet_rdma_queue_mutex);
1382 
1383 	if (disconnect)
1384 		__nvmet_rdma_queue_disconnect(queue);
1385 }
1386 
1387 static void nvmet_rdma_queue_connect_fail(struct rdma_cm_id *cm_id,
1388 		struct nvmet_rdma_queue *queue)
1389 {
1390 	WARN_ON_ONCE(queue->state != NVMET_RDMA_Q_CONNECTING);
1391 
1392 	mutex_lock(&nvmet_rdma_queue_mutex);
1393 	if (!list_empty(&queue->queue_list))
1394 		list_del_init(&queue->queue_list);
1395 	mutex_unlock(&nvmet_rdma_queue_mutex);
1396 
1397 	pr_err("failed to connect queue %d\n", queue->idx);
1398 	schedule_work(&queue->release_work);
1399 }
1400 
1401 /**
1402  * nvme_rdma_device_removal() - Handle RDMA device removal
1403  * @cm_id:	rdma_cm id, used for nvmet port
1404  * @queue:      nvmet rdma queue (cm id qp_context)
1405  *
1406  * DEVICE_REMOVAL event notifies us that the RDMA device is about
1407  * to unplug. Note that this event can be generated on a normal
1408  * queue cm_id and/or a device bound listener cm_id (where in this
1409  * case queue will be null).
1410  *
1411  * We registered an ib_client to handle device removal for queues,
1412  * so we only need to handle the listening port cm_ids. In this case
1413  * we nullify the priv to prevent double cm_id destruction and destroying
1414  * the cm_id implicitely by returning a non-zero rc to the callout.
1415  */
1416 static int nvmet_rdma_device_removal(struct rdma_cm_id *cm_id,
1417 		struct nvmet_rdma_queue *queue)
1418 {
1419 	struct nvmet_port *port;
1420 
1421 	if (queue) {
1422 		/*
1423 		 * This is a queue cm_id. we have registered
1424 		 * an ib_client to handle queues removal
1425 		 * so don't interfear and just return.
1426 		 */
1427 		return 0;
1428 	}
1429 
1430 	port = cm_id->context;
1431 
1432 	/*
1433 	 * This is a listener cm_id. Make sure that
1434 	 * future remove_port won't invoke a double
1435 	 * cm_id destroy. use atomic xchg to make sure
1436 	 * we don't compete with remove_port.
1437 	 */
1438 	if (xchg(&port->priv, NULL) != cm_id)
1439 		return 0;
1440 
1441 	/*
1442 	 * We need to return 1 so that the core will destroy
1443 	 * it's own ID.  What a great API design..
1444 	 */
1445 	return 1;
1446 }
1447 
1448 static int nvmet_rdma_cm_handler(struct rdma_cm_id *cm_id,
1449 		struct rdma_cm_event *event)
1450 {
1451 	struct nvmet_rdma_queue *queue = NULL;
1452 	int ret = 0;
1453 
1454 	if (cm_id->qp)
1455 		queue = cm_id->qp->qp_context;
1456 
1457 	pr_debug("%s (%d): status %d id %p\n",
1458 		rdma_event_msg(event->event), event->event,
1459 		event->status, cm_id);
1460 
1461 	switch (event->event) {
1462 	case RDMA_CM_EVENT_CONNECT_REQUEST:
1463 		ret = nvmet_rdma_queue_connect(cm_id, event);
1464 		break;
1465 	case RDMA_CM_EVENT_ESTABLISHED:
1466 		nvmet_rdma_queue_established(queue);
1467 		break;
1468 	case RDMA_CM_EVENT_ADDR_CHANGE:
1469 	case RDMA_CM_EVENT_DISCONNECTED:
1470 	case RDMA_CM_EVENT_TIMEWAIT_EXIT:
1471 		nvmet_rdma_queue_disconnect(queue);
1472 		break;
1473 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
1474 		ret = nvmet_rdma_device_removal(cm_id, queue);
1475 		break;
1476 	case RDMA_CM_EVENT_REJECTED:
1477 		pr_debug("Connection rejected: %s\n",
1478 			 rdma_reject_msg(cm_id, event->status));
1479 		/* FALLTHROUGH */
1480 	case RDMA_CM_EVENT_UNREACHABLE:
1481 	case RDMA_CM_EVENT_CONNECT_ERROR:
1482 		nvmet_rdma_queue_connect_fail(cm_id, queue);
1483 		break;
1484 	default:
1485 		pr_err("received unrecognized RDMA CM event %d\n",
1486 			event->event);
1487 		break;
1488 	}
1489 
1490 	return ret;
1491 }
1492 
1493 static void nvmet_rdma_delete_ctrl(struct nvmet_ctrl *ctrl)
1494 {
1495 	struct nvmet_rdma_queue *queue;
1496 
1497 restart:
1498 	mutex_lock(&nvmet_rdma_queue_mutex);
1499 	list_for_each_entry(queue, &nvmet_rdma_queue_list, queue_list) {
1500 		if (queue->nvme_sq.ctrl == ctrl) {
1501 			list_del_init(&queue->queue_list);
1502 			mutex_unlock(&nvmet_rdma_queue_mutex);
1503 
1504 			__nvmet_rdma_queue_disconnect(queue);
1505 			goto restart;
1506 		}
1507 	}
1508 	mutex_unlock(&nvmet_rdma_queue_mutex);
1509 }
1510 
1511 static int nvmet_rdma_add_port(struct nvmet_port *port)
1512 {
1513 	struct rdma_cm_id *cm_id;
1514 	struct sockaddr_storage addr = { };
1515 	__kernel_sa_family_t af;
1516 	int ret;
1517 
1518 	switch (port->disc_addr.adrfam) {
1519 	case NVMF_ADDR_FAMILY_IP4:
1520 		af = AF_INET;
1521 		break;
1522 	case NVMF_ADDR_FAMILY_IP6:
1523 		af = AF_INET6;
1524 		break;
1525 	default:
1526 		pr_err("address family %d not supported\n",
1527 				port->disc_addr.adrfam);
1528 		return -EINVAL;
1529 	}
1530 
1531 	if (port->inline_data_size < 0) {
1532 		port->inline_data_size = NVMET_RDMA_DEFAULT_INLINE_DATA_SIZE;
1533 	} else if (port->inline_data_size > NVMET_RDMA_MAX_INLINE_DATA_SIZE) {
1534 		pr_warn("inline_data_size %u is too large, reducing to %u\n",
1535 			port->inline_data_size,
1536 			NVMET_RDMA_MAX_INLINE_DATA_SIZE);
1537 		port->inline_data_size = NVMET_RDMA_MAX_INLINE_DATA_SIZE;
1538 	}
1539 
1540 	ret = inet_pton_with_scope(&init_net, af, port->disc_addr.traddr,
1541 			port->disc_addr.trsvcid, &addr);
1542 	if (ret) {
1543 		pr_err("malformed ip/port passed: %s:%s\n",
1544 			port->disc_addr.traddr, port->disc_addr.trsvcid);
1545 		return ret;
1546 	}
1547 
1548 	cm_id = rdma_create_id(&init_net, nvmet_rdma_cm_handler, port,
1549 			RDMA_PS_TCP, IB_QPT_RC);
1550 	if (IS_ERR(cm_id)) {
1551 		pr_err("CM ID creation failed\n");
1552 		return PTR_ERR(cm_id);
1553 	}
1554 
1555 	/*
1556 	 * Allow both IPv4 and IPv6 sockets to bind a single port
1557 	 * at the same time.
1558 	 */
1559 	ret = rdma_set_afonly(cm_id, 1);
1560 	if (ret) {
1561 		pr_err("rdma_set_afonly failed (%d)\n", ret);
1562 		goto out_destroy_id;
1563 	}
1564 
1565 	ret = rdma_bind_addr(cm_id, (struct sockaddr *)&addr);
1566 	if (ret) {
1567 		pr_err("binding CM ID to %pISpcs failed (%d)\n",
1568 			(struct sockaddr *)&addr, ret);
1569 		goto out_destroy_id;
1570 	}
1571 
1572 	ret = rdma_listen(cm_id, 128);
1573 	if (ret) {
1574 		pr_err("listening to %pISpcs failed (%d)\n",
1575 			(struct sockaddr *)&addr, ret);
1576 		goto out_destroy_id;
1577 	}
1578 
1579 	pr_info("enabling port %d (%pISpcs)\n",
1580 		le16_to_cpu(port->disc_addr.portid), (struct sockaddr *)&addr);
1581 	port->priv = cm_id;
1582 	return 0;
1583 
1584 out_destroy_id:
1585 	rdma_destroy_id(cm_id);
1586 	return ret;
1587 }
1588 
1589 static void nvmet_rdma_remove_port(struct nvmet_port *port)
1590 {
1591 	struct rdma_cm_id *cm_id = xchg(&port->priv, NULL);
1592 
1593 	if (cm_id)
1594 		rdma_destroy_id(cm_id);
1595 }
1596 
1597 static void nvmet_rdma_disc_port_addr(struct nvmet_req *req,
1598 		struct nvmet_port *port, char *traddr)
1599 {
1600 	struct rdma_cm_id *cm_id = port->priv;
1601 
1602 	if (inet_addr_is_any((struct sockaddr *)&cm_id->route.addr.src_addr)) {
1603 		struct nvmet_rdma_rsp *rsp =
1604 			container_of(req, struct nvmet_rdma_rsp, req);
1605 		struct rdma_cm_id *req_cm_id = rsp->queue->cm_id;
1606 		struct sockaddr *addr = (void *)&req_cm_id->route.addr.src_addr;
1607 
1608 		sprintf(traddr, "%pISc", addr);
1609 	} else {
1610 		memcpy(traddr, port->disc_addr.traddr, NVMF_TRADDR_SIZE);
1611 	}
1612 }
1613 
1614 static const struct nvmet_fabrics_ops nvmet_rdma_ops = {
1615 	.owner			= THIS_MODULE,
1616 	.type			= NVMF_TRTYPE_RDMA,
1617 	.msdbd			= 1,
1618 	.has_keyed_sgls		= 1,
1619 	.add_port		= nvmet_rdma_add_port,
1620 	.remove_port		= nvmet_rdma_remove_port,
1621 	.queue_response		= nvmet_rdma_queue_response,
1622 	.delete_ctrl		= nvmet_rdma_delete_ctrl,
1623 	.disc_traddr		= nvmet_rdma_disc_port_addr,
1624 };
1625 
1626 static void nvmet_rdma_remove_one(struct ib_device *ib_device, void *client_data)
1627 {
1628 	struct nvmet_rdma_queue *queue, *tmp;
1629 	struct nvmet_rdma_device *ndev;
1630 	bool found = false;
1631 
1632 	mutex_lock(&device_list_mutex);
1633 	list_for_each_entry(ndev, &device_list, entry) {
1634 		if (ndev->device == ib_device) {
1635 			found = true;
1636 			break;
1637 		}
1638 	}
1639 	mutex_unlock(&device_list_mutex);
1640 
1641 	if (!found)
1642 		return;
1643 
1644 	/*
1645 	 * IB Device that is used by nvmet controllers is being removed,
1646 	 * delete all queues using this device.
1647 	 */
1648 	mutex_lock(&nvmet_rdma_queue_mutex);
1649 	list_for_each_entry_safe(queue, tmp, &nvmet_rdma_queue_list,
1650 				 queue_list) {
1651 		if (queue->dev->device != ib_device)
1652 			continue;
1653 
1654 		pr_info("Removing queue %d\n", queue->idx);
1655 		list_del_init(&queue->queue_list);
1656 		__nvmet_rdma_queue_disconnect(queue);
1657 	}
1658 	mutex_unlock(&nvmet_rdma_queue_mutex);
1659 
1660 	flush_scheduled_work();
1661 }
1662 
1663 static struct ib_client nvmet_rdma_ib_client = {
1664 	.name   = "nvmet_rdma",
1665 	.remove = nvmet_rdma_remove_one
1666 };
1667 
1668 static int __init nvmet_rdma_init(void)
1669 {
1670 	int ret;
1671 
1672 	ret = ib_register_client(&nvmet_rdma_ib_client);
1673 	if (ret)
1674 		return ret;
1675 
1676 	ret = nvmet_register_transport(&nvmet_rdma_ops);
1677 	if (ret)
1678 		goto err_ib_client;
1679 
1680 	return 0;
1681 
1682 err_ib_client:
1683 	ib_unregister_client(&nvmet_rdma_ib_client);
1684 	return ret;
1685 }
1686 
1687 static void __exit nvmet_rdma_exit(void)
1688 {
1689 	nvmet_unregister_transport(&nvmet_rdma_ops);
1690 	ib_unregister_client(&nvmet_rdma_ib_client);
1691 	WARN_ON_ONCE(!list_empty(&nvmet_rdma_queue_list));
1692 	ida_destroy(&nvmet_rdma_queue_ida);
1693 }
1694 
1695 module_init(nvmet_rdma_init);
1696 module_exit(nvmet_rdma_exit);
1697 
1698 MODULE_LICENSE("GPL v2");
1699 MODULE_ALIAS("nvmet-transport-1"); /* 1 == NVMF_TRTYPE_RDMA */
1700