pvrdma_cq.c

  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 */
 63int 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 * @attrs: bundle
 98 *
 99 * @return: 0 on success
100 */
101int pvrdma_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr,
102		     struct uverbs_attr_bundle *attrs)
103{
104	struct ib_udata *udata = &attrs->driver_udata;
105	struct ib_device *ibdev = ibcq->device;
106	int entries = attr->cqe;
107	struct pvrdma_dev *dev = to_vdev(ibdev);
108	struct pvrdma_cq *cq = to_vcq(ibcq);
109	int ret;
110	int npages;
111	unsigned long flags;
112	union pvrdma_cmd_req req;
113	union pvrdma_cmd_resp rsp;
114	struct pvrdma_cmd_create_cq *cmd = &req.create_cq;
115	struct pvrdma_cmd_create_cq_resp *resp = &rsp.create_cq_resp;
116	struct pvrdma_create_cq_resp cq_resp = {};
117	struct pvrdma_create_cq ucmd;
118	struct pvrdma_ucontext *context = rdma_udata_to_drv_context(
119		udata, struct pvrdma_ucontext, ibucontext);
120
121	BUILD_BUG_ON(sizeof(struct pvrdma_cqe) != 64);
122
123	if (attr->flags)
124		return -EOPNOTSUPP;
125
126	entries = roundup_pow_of_two(entries);
127	if (entries < 1 || entries > dev->dsr->caps.max_cqe)
128		return -EINVAL;
129
130	if (!atomic_add_unless(&dev->num_cqs, 1, dev->dsr->caps.max_cq))
131		return -ENOMEM;
132
133	cq->ibcq.cqe = entries;
134	cq->is_kernel = !udata;
135
136	if (!cq->is_kernel) {
137		if (ib_copy_from_udata(&ucmd, udata, sizeof(ucmd))) {
138			ret = -EFAULT;
139			goto err_cq;
140		}
141
142		cq->umem = ib_umem_get(ibdev, ucmd.buf_addr, ucmd.buf_size,
143				       IB_ACCESS_LOCAL_WRITE);
144		if (IS_ERR(cq->umem)) {
145			ret = PTR_ERR(cq->umem);
146			goto err_cq;
147		}
148
149		npages = ib_umem_num_dma_blocks(cq->umem, PAGE_SIZE);
150	} else {
151		/* One extra page for shared ring state */
152		npages = 1 + (entries * sizeof(struct pvrdma_cqe) +
153			      PAGE_SIZE - 1) / PAGE_SIZE;
154
155		/* Skip header page. */
156		cq->offset = PAGE_SIZE;
157	}
158
159	if (npages < 0 || npages > PVRDMA_PAGE_DIR_MAX_PAGES) {
160		dev_warn(&dev->pdev->dev,
161			 "overflow pages in completion queue\n");
162		ret = -EINVAL;
163		goto err_umem;
164	}
165
166	ret = pvrdma_page_dir_init(dev, &cq->pdir, npages, cq->is_kernel);
167	if (ret) {
168		dev_warn(&dev->pdev->dev,
169			 "could not allocate page directory\n");
170		goto err_umem;
171	}
172
173	/* Ring state is always the first page. Set in library for user cq. */
174	if (cq->is_kernel)
175		cq->ring_state = cq->pdir.pages[0];
176	else
177		pvrdma_page_dir_insert_umem(&cq->pdir, cq->umem, 0);
178
179	refcount_set(&cq->refcnt, 1);
180	init_completion(&cq->free);
181	spin_lock_init(&cq->cq_lock);
182
183	memset(cmd, 0, sizeof(*cmd));
184	cmd->hdr.cmd = PVRDMA_CMD_CREATE_CQ;
185	cmd->nchunks = npages;
186	cmd->ctx_handle = context ? context->ctx_handle : 0;
187	cmd->cqe = entries;
188	cmd->pdir_dma = cq->pdir.dir_dma;
189	ret = pvrdma_cmd_post(dev, &req, &rsp, PVRDMA_CMD_CREATE_CQ_RESP);
190	if (ret < 0) {
191		dev_warn(&dev->pdev->dev,
192			 "could not create completion queue, error: %d\n", ret);
193		goto err_page_dir;
194	}
195
196	cq->ibcq.cqe = resp->cqe;
197	cq->cq_handle = resp->cq_handle;
198	cq_resp.cqn = resp->cq_handle;
199	spin_lock_irqsave(&dev->cq_tbl_lock, flags);
200	dev->cq_tbl[cq->cq_handle % dev->dsr->caps.max_cq] = cq;
201	spin_unlock_irqrestore(&dev->cq_tbl_lock, flags);
202
203	if (!cq->is_kernel) {
204		cq->uar = &context->uar;
205
206		/* Copy udata back. */
207		if (ib_copy_to_udata(udata, &cq_resp, sizeof(cq_resp))) {
208			dev_warn(&dev->pdev->dev,
209				 "failed to copy back udata\n");
210			pvrdma_destroy_cq(&cq->ibcq, udata);
211			return -EINVAL;
212		}
213	}
214
215	return 0;
216
217err_page_dir:
218	pvrdma_page_dir_cleanup(dev, &cq->pdir);
219err_umem:
220	ib_umem_release(cq->umem);
221err_cq:
222	atomic_dec(&dev->num_cqs);
223	return ret;
224}
225
226static void pvrdma_free_cq(struct pvrdma_dev *dev, struct pvrdma_cq *cq)
227{
228	if (refcount_dec_and_test(&cq->refcnt))
229		complete(&cq->free);
230	wait_for_completion(&cq->free);
231
232	ib_umem_release(cq->umem);
233
234	pvrdma_page_dir_cleanup(dev, &cq->pdir);
235}
236
237/**
238 * pvrdma_destroy_cq - destroy completion queue
239 * @cq: the completion queue to destroy.
240 * @udata: user data or null for kernel object
241 */
242int pvrdma_destroy_cq(struct ib_cq *cq, struct ib_udata *udata)
243{
244	struct pvrdma_cq *vcq = to_vcq(cq);
245	union pvrdma_cmd_req req;
246	struct pvrdma_cmd_destroy_cq *cmd = &req.destroy_cq;
247	struct pvrdma_dev *dev = to_vdev(cq->device);
248	unsigned long flags;
249	int ret;
250
251	memset(cmd, 0, sizeof(*cmd));
252	cmd->hdr.cmd = PVRDMA_CMD_DESTROY_CQ;
253	cmd->cq_handle = vcq->cq_handle;
254
255	ret = pvrdma_cmd_post(dev, &req, NULL, 0);
256	if (ret < 0)
257		dev_warn(&dev->pdev->dev,
258			 "could not destroy completion queue, error: %d\n",
259			 ret);
260
261	/* free cq's resources */
262	spin_lock_irqsave(&dev->cq_tbl_lock, flags);
263	dev->cq_tbl[vcq->cq_handle] = NULL;
264	spin_unlock_irqrestore(&dev->cq_tbl_lock, flags);
265
266	pvrdma_free_cq(dev, vcq);
267	atomic_dec(&dev->num_cqs);
268	return 0;
269}
270
271static inline struct pvrdma_cqe *get_cqe(struct pvrdma_cq *cq, int i)
272{
273	return (struct pvrdma_cqe *)pvrdma_page_dir_get_ptr(
274					&cq->pdir,
275					cq->offset +
276					sizeof(struct pvrdma_cqe) * i);
277}
278
279void _pvrdma_flush_cqe(struct pvrdma_qp *qp, struct pvrdma_cq *cq)
280{
281	unsigned int head;
282	int has_data;
283
284	if (!cq->is_kernel)
285		return;
286
287	/* Lock held */
288	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
289					    cq->ibcq.cqe, &head);
290	if (unlikely(has_data > 0)) {
291		int items;
292		int curr;
293		int tail = pvrdma_idx(&cq->ring_state->rx.prod_tail,
294				      cq->ibcq.cqe);
295		struct pvrdma_cqe *cqe;
296		struct pvrdma_cqe *curr_cqe;
297
298		items = (tail > head) ? (tail - head) :
299			(cq->ibcq.cqe - head + tail);
300		curr = --tail;
301		while (items-- > 0) {
302			if (curr < 0)
303				curr = cq->ibcq.cqe - 1;
304			if (tail < 0)
305				tail = cq->ibcq.cqe - 1;
306			curr_cqe = get_cqe(cq, curr);
307			if ((curr_cqe->qp & 0xFFFF) != qp->qp_handle) {
308				if (curr != tail) {
309					cqe = get_cqe(cq, tail);
310					*cqe = *curr_cqe;
311				}
312				tail--;
313			} else {
314				pvrdma_idx_ring_inc(
315					&cq->ring_state->rx.cons_head,
316					cq->ibcq.cqe);
317			}
318			curr--;
319		}
320	}
321}
322
323static int pvrdma_poll_one(struct pvrdma_cq *cq, struct pvrdma_qp **cur_qp,
324			   struct ib_wc *wc)
325{
326	struct pvrdma_dev *dev = to_vdev(cq->ibcq.device);
327	int has_data;
328	unsigned int head;
329	bool tried = false;
330	struct pvrdma_cqe *cqe;
331
332retry:
333	has_data = pvrdma_idx_ring_has_data(&cq->ring_state->rx,
334					    cq->ibcq.cqe, &head);
335	if (has_data == 0) {
336		if (tried)
337			return -EAGAIN;
338
339		pvrdma_write_uar_cq(dev, cq->cq_handle | PVRDMA_UAR_CQ_POLL);
340
341		tried = true;
342		goto retry;
343	} else if (has_data == PVRDMA_INVALID_IDX) {
344		dev_err(&dev->pdev->dev, "CQ ring state invalid\n");
345		return -EAGAIN;
346	}
347
348	cqe = get_cqe(cq, head);
349
350	/* Ensure cqe is valid. */
351	rmb();
352	if (dev->qp_tbl[cqe->qp & 0xffff])
353		*cur_qp = (struct pvrdma_qp *)dev->qp_tbl[cqe->qp & 0xffff];
354	else
355		return -EAGAIN;
356
357	wc->opcode = pvrdma_wc_opcode_to_ib(cqe->opcode);
358	wc->status = pvrdma_wc_status_to_ib(cqe->status);
359	wc->wr_id = cqe->wr_id;
360	wc->qp = &(*cur_qp)->ibqp;
361	wc->byte_len = cqe->byte_len;
362	wc->ex.imm_data = cqe->imm_data;
363	wc->src_qp = cqe->src_qp;
364	wc->wc_flags = pvrdma_wc_flags_to_ib(cqe->wc_flags);
365	wc->pkey_index = cqe->pkey_index;
366	wc->slid = cqe->slid;
367	wc->sl = cqe->sl;
368	wc->dlid_path_bits = cqe->dlid_path_bits;
369	wc->port_num = cqe->port_num;
370	wc->vendor_err = cqe->vendor_err;
371	wc->network_hdr_type = pvrdma_network_type_to_ib(cqe->network_hdr_type);
372
373	/* Update shared ring state */
374	pvrdma_idx_ring_inc(&cq->ring_state->rx.cons_head, cq->ibcq.cqe);
375
376	return 0;
377}
378
379/**
380 * pvrdma_poll_cq - poll for work completion queue entries
381 * @ibcq: completion queue
382 * @num_entries: the maximum number of entries
383 * @wc: pointer to work completion array
384 *
385 * @return: number of polled completion entries
386 */
387int pvrdma_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *wc)
388{
389	struct pvrdma_cq *cq = to_vcq(ibcq);
390	struct pvrdma_qp *cur_qp = NULL;
391	unsigned long flags;
392	int npolled;
393
394	if (num_entries < 1 || wc == NULL)
395		return 0;
396
397	spin_lock_irqsave(&cq->cq_lock, flags);
398	for (npolled = 0; npolled < num_entries; ++npolled) {
399		if (pvrdma_poll_one(cq, &cur_qp, wc + npolled))
400			break;
401	}
402
403	spin_unlock_irqrestore(&cq->cq_lock, flags);
404
405	/* Ensure we do not return errors from poll_cq */
406	return npolled;
407}