1 /*
2  * Copyright (c) 2012-2016 VMware, Inc.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of EITHER the GNU General Public License
6  * version 2 as published by the Free Software Foundation or the BSD
7  * 2-Clause License. This program is distributed in the hope that it
8  * will be useful, but WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED
9  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
10  * See the GNU General Public License version 2 for more details at
11  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program available in the file COPYING in the main
15  * directory of this source tree.
16  *
17  * The BSD 2-Clause License
18  *
19  *     Redistribution and use in source and binary forms, with or
20  *     without modification, are permitted provided that the following
21  *     conditions are met:
22  *
23  *      - Redistributions of source code must retain the above
24  *        copyright notice, this list of conditions and the following
25  *        disclaimer.
26  *
27  *      - Redistributions in binary form must reproduce the above
28  *        copyright notice, this list of conditions and the following
29  *        disclaimer in the documentation and/or other materials
30  *        provided with the distribution.
31  *
32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
33  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
34  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
35  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
36  * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
37  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
38  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
39  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
41  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
42  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
43  * OF THE POSSIBILITY OF SUCH DAMAGE.
44  */
45 
46 #include <asm/page.h>
47 #include <linux/io.h>
48 #include <linux/wait.h>
49 #include <rdma/ib_addr.h>
50 #include <rdma/ib_smi.h>
51 #include <rdma/ib_user_verbs.h>
52 #include <rdma/uverbs_ioctl.h>
53 
54 #include "pvrdma.h"
55 
56 /**
57  * pvrdma_req_notify_cq - request notification for a completion queue
58  * @ibcq: the completion queue
59  * @notify_flags: notification flags
60  *
61  * @return: 0 for success.
62  */
63 int pvrdma_req_notify_cq(struct ib_cq *ibcq,
64 			 enum ib_cq_notify_flags notify_flags)
65 {
66 	struct pvrdma_dev *dev = to_vdev(ibcq->device);
67 	struct pvrdma_cq *cq = to_vcq(ibcq);
68 	u32 val = cq->cq_handle;
69 	unsigned long flags;
70 	int has_data = 0;
71 
72 	val |= (notify_flags & IB_CQ_SOLICITED_MASK) == IB_CQ_SOLICITED ?
73 		PVRDMA_UAR_CQ_ARM_SOL : PVRDMA_UAR_CQ_ARM;
74 
75 	spin_lock_irqsave(&cq->cq_lock, flags);
76 
77 	pvrdma_write_uar_cq(dev, val);
78 
79 	if (notify_flags & IB_CQ_REPORT_MISSED_EVENTS) {
80 		unsigned int head;
81 
82 		has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
83 						    cq->ibcq.cqe, &head);
84 		if (unlikely(has_data == PVRDMA_INVALID_IDX))
85 			dev_err(&dev->pdev->dev, "CQ ring state invalid\n");
86 	}
87 
88 	spin_unlock_irqrestore(&cq->cq_lock, flags);
89 
90 	return has_data;
91 }
92 
93 /**
94  * pvrdma_create_cq - create completion queue
95  * @ibcq: Allocated CQ
96  * @attr: completion queue attributes
97  * @udata: user data
98  *
99  * @return: 0 on success
100  */
101 int pvrdma_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
102 		     struct ib_udata *udata)
103 {
104 	struct ib_device *ibdev = ibcq->device;
105 	int entries = attr->cqe;
106 	struct pvrdma_dev *dev = to_vdev(ibdev);
107 	struct pvrdma_cq *cq = to_vcq(ibcq);
108 	int ret;
109 	int npages;
110 	unsigned long flags;
111 	union pvrdma_cmd_req req;
112 	union pvrdma_cmd_resp rsp;
113 	struct pvrdma_cmd_create_cq *cmd = &req.create_cq;
114 	struct pvrdma_cmd_create_cq_resp *resp = &rsp.create_cq_resp;
115 	struct pvrdma_create_cq_resp cq_resp = {};
116 	struct pvrdma_create_cq ucmd;
117 	struct pvrdma_ucontext *context = rdma_udata_to_drv_context(
118 		udata, struct pvrdma_ucontext, ibucontext);
119 
120 	BUILD_BUG_ON(sizeof(struct pvrdma_cqe) != 64);
121 
122 	entries = roundup_pow_of_two(entries);
123 	if (entries < 1 || entries > dev->dsr->caps.max_cqe)
124 		return -EINVAL;
125 
126 	if (!atomic_add_unless(&dev->num_cqs, 1, dev->dsr->caps.max_cq))
127 		return -ENOMEM;
128 
129 	cq->ibcq.cqe = entries;
130 	cq->is_kernel = !udata;
131 
132 	if (!cq->is_kernel) {
133 		if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) {
134 			ret = -EFAULT;
135 			goto err_cq;
136 		}
137 
138 		cq->umem = ib_umem_get(ibdev, ucmd.buf_addr, ucmd.buf_size,
139 				       IB_ACCESS_LOCAL_WRITE);
140 		if (IS_ERR(cq->umem)) {
141 			ret = PTR_ERR(cq->umem);
142 			goto err_cq;
143 		}
144 
145 		npages = ib_umem_page_count(cq->umem);
146 	} else {
147 		/* One extra page for shared ring state */
148 		npages = 1 + (entries * sizeof(struct pvrdma_cqe) +
149 			      PAGE_SIZE - 1) / PAGE_SIZE;
150 
151 		/* Skip header page. */
152 		cq->offset = PAGE_SIZE;
153 	}
154 
155 	if (npages < 0 || npages > PVRDMA_PAGE_DIR_MAX_PAGES) {
156 		dev_warn(&dev->pdev->dev,
157 			 "overflow pages in completion queue\n");
158 		ret = -EINVAL;
159 		goto err_umem;
160 	}
161 
162 	ret = pvrdma_page_dir_init(dev, &cq->pdir, npages, cq->is_kernel);
163 	if (ret) {
164 		dev_warn(&dev->pdev->dev,
165 			 "could not allocate page directory\n");
166 		goto err_umem;
167 	}
168 
169 	/* Ring state is always the first page. Set in library for user cq. */
170 	if (cq->is_kernel)
171 		cq->ring_state = cq->pdir.pages[0];
172 	else
173 		pvrdma_page_dir_insert_umem(&cq->pdir, cq->umem, 0);
174 
175 	refcount_set(&cq->refcnt, 1);
176 	init_completion(&cq->free);
177 	spin_lock_init(&cq->cq_lock);
178 
179 	memset(cmd, 0, sizeof(*cmd));
180 	cmd->hdr.cmd = PVRDMA_CMD_CREATE_CQ;
181 	cmd->nchunks = npages;
182 	cmd->ctx_handle = context ? context->ctx_handle : 0;
183 	cmd->cqe = entries;
184 	cmd->pdir_dma = cq->pdir.dir_dma;
185 	ret = pvrdma_cmd_post(dev, &req, &rsp, PVRDMA_CMD_CREATE_CQ_RESP);
186 	if (ret < 0) {
187 		dev_warn(&dev->pdev->dev,
188 			 "could not create completion queue, error: %d\n", ret);
189 		goto err_page_dir;
190 	}
191 
192 	cq->ibcq.cqe = resp->cqe;
193 	cq->cq_handle = resp->cq_handle;
194 	cq_resp.cqn = resp->cq_handle;
195 	spin_lock_irqsave(&dev->cq_tbl_lock, flags);
196 	dev->cq_tbl[cq->cq_handle % dev->dsr->caps.max_cq] = cq;
197 	spin_unlock_irqrestore(&dev->cq_tbl_lock, flags);
198 
199 	if (!cq->is_kernel) {
200 		cq->uar = &context->uar;
201 
202 		/* Copy udata back. */
203 		if (ib_copy_to_udata(udata, &cq_resp, sizeof(cq_resp))) {
204 			dev_warn(&dev->pdev->dev,
205 				 "failed to copy back udata\n");
206 			pvrdma_destroy_cq(&cq->ibcq, udata);
207 			return -EINVAL;
208 		}
209 	}
210 
211 	return 0;
212 
213 err_page_dir:
214 	pvrdma_page_dir_cleanup(dev, &cq->pdir);
215 err_umem:
216 	ib_umem_release(cq->umem);
217 err_cq:
218 	atomic_dec(&dev->num_cqs);
219 	return ret;
220 }
221 
222 static void pvrdma_free_cq(struct pvrdma_dev *dev, struct pvrdma_cq *cq)
223 {
224 	if (refcount_dec_and_test(&cq->refcnt))
225 		complete(&cq->free);
226 	wait_for_completion(&cq->free);
227 
228 	ib_umem_release(cq->umem);
229 
230 	pvrdma_page_dir_cleanup(dev, &cq->pdir);
231 }
232 
233 /**
234  * pvrdma_destroy_cq - destroy completion queue
235  * @cq: the completion queue to destroy.
236  * @udata: user data or null for kernel object
237  */
238 void pvrdma_destroy_cq(struct ib_cq *cq, struct ib_udata *udata)
239 {
240 	struct pvrdma_cq *vcq = to_vcq(cq);
241 	union pvrdma_cmd_req req;
242 	struct pvrdma_cmd_destroy_cq *cmd = &req.destroy_cq;
243 	struct pvrdma_dev *dev = to_vdev(cq->device);
244 	unsigned long flags;
245 	int ret;
246 
247 	memset(cmd, 0, sizeof(*cmd));
248 	cmd->hdr.cmd = PVRDMA_CMD_DESTROY_CQ;
249 	cmd->cq_handle = vcq->cq_handle;
250 
251 	ret = pvrdma_cmd_post(dev, &req, NULL, 0);
252 	if (ret < 0)
253 		dev_warn(&dev->pdev->dev,
254 			 "could not destroy completion queue, error: %d\n",
255 			 ret);
256 
257 	/* free cq's resources */
258 	spin_lock_irqsave(&dev->cq_tbl_lock, flags);
259 	dev->cq_tbl[vcq->cq_handle] = NULL;
260 	spin_unlock_irqrestore(&dev->cq_tbl_lock, flags);
261 
262 	pvrdma_free_cq(dev, vcq);
263 	atomic_dec(&dev->num_cqs);
264 }
265 
266 static inline struct pvrdma_cqe *get_cqe(struct pvrdma_cq *cq, int i)
267 {
268 	return (struct pvrdma_cqe *)pvrdma_page_dir_get_ptr(
269 					&cq->pdir,
270 					cq->offset +
271 					sizeof(struct pvrdma_cqe) * i);
272 }
273 
274 void _pvrdma_flush_cqe(struct pvrdma_qp *qp, struct pvrdma_cq *cq)
275 {
276 	unsigned int head;
277 	int has_data;
278 
279 	if (!cq->is_kernel)
280 		return;
281 
282 	/* Lock held */
283 	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
284 					    cq->ibcq.cqe, &head);
285 	if (unlikely(has_data > 0)) {
286 		int items;
287 		int curr;
288 		int tail = pvrdma_idx(&cq->ring_state->rx.prod_tail,
289 				      cq->ibcq.cqe);
290 		struct pvrdma_cqe *cqe;
291 		struct pvrdma_cqe *curr_cqe;
292 
293 		items = (tail > head) ? (tail - head) :
294 			(cq->ibcq.cqe - head + tail);
295 		curr = --tail;
296 		while (items-- > 0) {
297 			if (curr < 0)
298 				curr = cq->ibcq.cqe - 1;
299 			if (tail < 0)
300 				tail = cq->ibcq.cqe - 1;
301 			curr_cqe = get_cqe(cq, curr);
302 			if ((curr_cqe->qp & 0xFFFF) != qp->qp_handle) {
303 				if (curr != tail) {
304 					cqe = get_cqe(cq, tail);
305 					*cqe = *curr_cqe;
306 				}
307 				tail--;
308 			} else {
309 				pvrdma_idx_ring_inc(
310 					&cq->ring_state->rx.cons_head,
311 					cq->ibcq.cqe);
312 			}
313 			curr--;
314 		}
315 	}
316 }
317 
318 static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp **cur_qp,
319 			   struct ib_wc *wc)
320 {
321 	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
322 	int has_data;
323 	unsigned int head;
324 	bool tried = false;
325 	struct pvrdma_cqe *cqe;
326 
327 retry:
328 	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
329 					    cq->ibcq.cqe, &head);
330 	if (has_data == 0) {
331 		if (tried)
332 			return -EAGAIN;
333 
334 		pvrdma_write_uar_cq(dev, cq->cq_handle | PVRDMA_UAR_CQ_POLL);
335 
336 		tried = true;
337 		goto retry;
338 	} else if (has_data == PVRDMA_INVALID_IDX) {
339 		dev_err(&dev->pdev->dev, "CQ ring state invalid\n");
340 		return -EAGAIN;
341 	}
342 
343 	cqe = get_cqe(cq, head);
344 
345 	/* Ensure cqe is valid. */
346 	rmb();
347 	if (dev->qp_tbl[cqe->qp & 0xffff])
348 		*cur_qp = (struct pvrdma_qp *)dev->qp_tbl[cqe->qp & 0xffff];
349 	else
350 		return -EAGAIN;
351 
352 	wc->opcode = pvrdma_wc_opcode_to_ib(cqe->opcode);
353 	wc->status = pvrdma_wc_status_to_ib(cqe->status);
354 	wc->wr_id = cqe->wr_id;
355 	wc->qp = &(*cur_qp)->ibqp;
356 	wc->byte_len = cqe->byte_len;
357 	wc->ex.imm_data = cqe->imm_data;
358 	wc->src_qp = cqe->src_qp;
359 	wc->wc_flags = pvrdma_wc_flags_to_ib(cqe->wc_flags);
360 	wc->pkey_index = cqe->pkey_index;
361 	wc->slid = cqe->slid;
362 	wc->sl = cqe->sl;
363 	wc->dlid_path_bits = cqe->dlid_path_bits;
364 	wc->port_num = cqe->port_num;
365 	wc->vendor_err = cqe->vendor_err;
366 	wc->network_hdr_type = cqe->network_hdr_type;
367 
368 	/* Update shared ring state */
369 	pvrdma_idx_ring_inc(&cq->ring_state->rx.cons_head, cq->ibcq.cqe);
370 
371 	return 0;
372 }
373 
374 /**
375  * pvrdma_poll_cq - poll for work completion queue entries
376  * @ibcq: completion queue
377  * @num_entries: the maximum number of entries
378  * @entry: pointer to work completion array
379  *
380  * @return: number of polled completion entries
381  */
382 int pvrdma_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
383 {
384 	struct pvrdma_cq *cq = to_vcq(ibcq);
385 	struct pvrdma_qp *cur_qp = NULL;
386 	unsigned long flags;
387 	int npolled;
388 
389 	if (num_entries < 1 || wc == NULL)
390 		return 0;
391 
392 	spin_lock_irqsave(&cq->cq_lock, flags);
393 	for (npolled = 0; npolled < num_entries; ++npolled) {
394 		if (pvrdma_poll_one(cq, &cur_qp, wc + npolled))
395 			break;
396 	}
397 
398 	spin_unlock_irqrestore(&cq->cq_lock, flags);
399 
400 	/* Ensure we do not return errors from poll_cq */
401 	return npolled;
402 }
403