1 /*
2  * Copyright (c) 2006, 2007, 2008, 2009 QLogic Corporation. All rights reserved.
3  * Copyright (c) 2005, 2006 PathScale, Inc. All rights reserved.
4  *
5  * This software is available to you under a choice of one of two
6  * licenses.  You may choose to be licensed under the terms of the GNU
7  * General Public License (GPL) Version 2, available from the file
8  * COPYING in the main directory of this source tree, or the
9  * OpenIB.org BSD license below:
10  *
11  *     Redistribution and use in source and binary forms, with or
12  *     without modification, are permitted provided that the following
13  *     conditions are met:
14  *
15  *      - Redistributions of source code must retain the above
16  *        copyright notice, this list of conditions and the following
17  *        disclaimer.
18  *
19  *      - Redistributions in binary form must reproduce the above
20  *        copyright notice, this list of conditions and the following
21  *        disclaimer in the documentation and/or other materials
22  *        provided with the distribution.
23  *
24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
31  * SOFTWARE.
32  */
33 
34 #include <linux/err.h>
35 #include <linux/slab.h>
36 #include <linux/vmalloc.h>
37 
38 #include "qib_verbs.h"
39 
40 /**
41  * qib_post_srq_receive - post a receive on a shared receive queue
42  * @ibsrq: the SRQ to post the receive on
43  * @wr: the list of work requests to post
44  * @bad_wr: A pointer to the first WR to cause a problem is put here
45  *
46  * This may be called from interrupt context.
47  */
qib_post_srq_receive(struct ib_srq * ibsrq,struct ib_recv_wr * wr,struct ib_recv_wr ** bad_wr)48 int qib_post_srq_receive(struct ib_srq *ibsrq, struct ib_recv_wr *wr,
49 			 struct ib_recv_wr **bad_wr)
50 {
51 	struct qib_srq *srq = to_isrq(ibsrq);
52 	struct qib_rwq *wq;
53 	unsigned long flags;
54 	int ret;
55 
56 	for (; wr; wr = wr->next) {
57 		struct qib_rwqe *wqe;
58 		u32 next;
59 		int i;
60 
61 		if ((unsigned) wr->num_sge > srq->rq.max_sge) {
62 			*bad_wr = wr;
63 			ret = -EINVAL;
64 			goto bail;
65 		}
66 
67 		spin_lock_irqsave(&srq->rq.lock, flags);
68 		wq = srq->rq.wq;
69 		next = wq->head + 1;
70 		if (next >= srq->rq.size)
71 			next = 0;
72 		if (next == wq->tail) {
73 			spin_unlock_irqrestore(&srq->rq.lock, flags);
74 			*bad_wr = wr;
75 			ret = -ENOMEM;
76 			goto bail;
77 		}
78 
79 		wqe = get_rwqe_ptr(&srq->rq, wq->head);
80 		wqe->wr_id = wr->wr_id;
81 		wqe->num_sge = wr->num_sge;
82 		for (i = 0; i < wr->num_sge; i++)
83 			wqe->sg_list[i] = wr->sg_list[i];
84 		/* Make sure queue entry is written before the head index. */
85 		smp_wmb();
86 		wq->head = next;
87 		spin_unlock_irqrestore(&srq->rq.lock, flags);
88 	}
89 	ret = 0;
90 
91 bail:
92 	return ret;
93 }
94 
95 /**
96  * qib_create_srq - create a shared receive queue
97  * @ibpd: the protection domain of the SRQ to create
98  * @srq_init_attr: the attributes of the SRQ
99  * @udata: data from libibverbs when creating a user SRQ
100  */
qib_create_srq(struct ib_pd * ibpd,struct ib_srq_init_attr * srq_init_attr,struct ib_udata * udata)101 struct ib_srq *qib_create_srq(struct ib_pd *ibpd,
102 			      struct ib_srq_init_attr *srq_init_attr,
103 			      struct ib_udata *udata)
104 {
105 	struct qib_ibdev *dev = to_idev(ibpd->device);
106 	struct qib_srq *srq;
107 	u32 sz;
108 	struct ib_srq *ret;
109 
110 	if (srq_init_attr->srq_type != IB_SRQT_BASIC) {
111 		ret = ERR_PTR(-ENOSYS);
112 		goto done;
113 	}
114 
115 	if (srq_init_attr->attr.max_sge == 0 ||
116 	    srq_init_attr->attr.max_sge > ib_qib_max_srq_sges ||
117 	    srq_init_attr->attr.max_wr == 0 ||
118 	    srq_init_attr->attr.max_wr > ib_qib_max_srq_wrs) {
119 		ret = ERR_PTR(-EINVAL);
120 		goto done;
121 	}
122 
123 	srq = kmalloc(sizeof(*srq), GFP_KERNEL);
124 	if (!srq) {
125 		ret = ERR_PTR(-ENOMEM);
126 		goto done;
127 	}
128 
129 	/*
130 	 * Need to use vmalloc() if we want to support large #s of entries.
131 	 */
132 	srq->rq.size = srq_init_attr->attr.max_wr + 1;
133 	srq->rq.max_sge = srq_init_attr->attr.max_sge;
134 	sz = sizeof(struct ib_sge) * srq->rq.max_sge +
135 		sizeof(struct qib_rwqe);
136 	srq->rq.wq = vmalloc_user(sizeof(struct qib_rwq) + srq->rq.size * sz);
137 	if (!srq->rq.wq) {
138 		ret = ERR_PTR(-ENOMEM);
139 		goto bail_srq;
140 	}
141 
142 	/*
143 	 * Return the address of the RWQ as the offset to mmap.
144 	 * See qib_mmap() for details.
145 	 */
146 	if (udata && udata->outlen >= sizeof(__u64)) {
147 		int err;
148 		u32 s = sizeof(struct qib_rwq) + srq->rq.size * sz;
149 
150 		srq->ip =
151 		    qib_create_mmap_info(dev, s, ibpd->uobject->context,
152 					 srq->rq.wq);
153 		if (!srq->ip) {
154 			ret = ERR_PTR(-ENOMEM);
155 			goto bail_wq;
156 		}
157 
158 		err = ib_copy_to_udata(udata, &srq->ip->offset,
159 				       sizeof(srq->ip->offset));
160 		if (err) {
161 			ret = ERR_PTR(err);
162 			goto bail_ip;
163 		}
164 	} else
165 		srq->ip = NULL;
166 
167 	/*
168 	 * ib_create_srq() will initialize srq->ibsrq.
169 	 */
170 	spin_lock_init(&srq->rq.lock);
171 	srq->rq.wq->head = 0;
172 	srq->rq.wq->tail = 0;
173 	srq->limit = srq_init_attr->attr.srq_limit;
174 
175 	spin_lock(&dev->n_srqs_lock);
176 	if (dev->n_srqs_allocated == ib_qib_max_srqs) {
177 		spin_unlock(&dev->n_srqs_lock);
178 		ret = ERR_PTR(-ENOMEM);
179 		goto bail_ip;
180 	}
181 
182 	dev->n_srqs_allocated++;
183 	spin_unlock(&dev->n_srqs_lock);
184 
185 	if (srq->ip) {
186 		spin_lock_irq(&dev->pending_lock);
187 		list_add(&srq->ip->pending_mmaps, &dev->pending_mmaps);
188 		spin_unlock_irq(&dev->pending_lock);
189 	}
190 
191 	ret = &srq->ibsrq;
192 	goto done;
193 
194 bail_ip:
195 	kfree(srq->ip);
196 bail_wq:
197 	vfree(srq->rq.wq);
198 bail_srq:
199 	kfree(srq);
200 done:
201 	return ret;
202 }
203 
204 /**
205  * qib_modify_srq - modify a shared receive queue
206  * @ibsrq: the SRQ to modify
207  * @attr: the new attributes of the SRQ
208  * @attr_mask: indicates which attributes to modify
209  * @udata: user data for libibverbs.so
210  */
qib_modify_srq(struct ib_srq * ibsrq,struct ib_srq_attr * attr,enum ib_srq_attr_mask attr_mask,struct ib_udata * udata)211 int qib_modify_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr,
212 		   enum ib_srq_attr_mask attr_mask,
213 		   struct ib_udata *udata)
214 {
215 	struct qib_srq *srq = to_isrq(ibsrq);
216 	struct qib_rwq *wq;
217 	int ret = 0;
218 
219 	if (attr_mask & IB_SRQ_MAX_WR) {
220 		struct qib_rwq *owq;
221 		struct qib_rwqe *p;
222 		u32 sz, size, n, head, tail;
223 
224 		/* Check that the requested sizes are below the limits. */
225 		if ((attr->max_wr > ib_qib_max_srq_wrs) ||
226 		    ((attr_mask & IB_SRQ_LIMIT) ?
227 		     attr->srq_limit : srq->limit) > attr->max_wr) {
228 			ret = -EINVAL;
229 			goto bail;
230 		}
231 
232 		sz = sizeof(struct qib_rwqe) +
233 			srq->rq.max_sge * sizeof(struct ib_sge);
234 		size = attr->max_wr + 1;
235 		wq = vmalloc_user(sizeof(struct qib_rwq) + size * sz);
236 		if (!wq) {
237 			ret = -ENOMEM;
238 			goto bail;
239 		}
240 
241 		/* Check that we can write the offset to mmap. */
242 		if (udata && udata->inlen >= sizeof(__u64)) {
243 			__u64 offset_addr;
244 			__u64 offset = 0;
245 
246 			ret = ib_copy_from_udata(&offset_addr, udata,
247 						 sizeof(offset_addr));
248 			if (ret)
249 				goto bail_free;
250 			udata->outbuf =
251 				(void __user *) (unsigned long) offset_addr;
252 			ret = ib_copy_to_udata(udata, &offset,
253 					       sizeof(offset));
254 			if (ret)
255 				goto bail_free;
256 		}
257 
258 		spin_lock_irq(&srq->rq.lock);
259 		/*
260 		 * validate head and tail pointer values and compute
261 		 * the number of remaining WQEs.
262 		 */
263 		owq = srq->rq.wq;
264 		head = owq->head;
265 		tail = owq->tail;
266 		if (head >= srq->rq.size || tail >= srq->rq.size) {
267 			ret = -EINVAL;
268 			goto bail_unlock;
269 		}
270 		n = head;
271 		if (n < tail)
272 			n += srq->rq.size - tail;
273 		else
274 			n -= tail;
275 		if (size <= n) {
276 			ret = -EINVAL;
277 			goto bail_unlock;
278 		}
279 		n = 0;
280 		p = wq->wq;
281 		while (tail != head) {
282 			struct qib_rwqe *wqe;
283 			int i;
284 
285 			wqe = get_rwqe_ptr(&srq->rq, tail);
286 			p->wr_id = wqe->wr_id;
287 			p->num_sge = wqe->num_sge;
288 			for (i = 0; i < wqe->num_sge; i++)
289 				p->sg_list[i] = wqe->sg_list[i];
290 			n++;
291 			p = (struct qib_rwqe *)((char *) p + sz);
292 			if (++tail >= srq->rq.size)
293 				tail = 0;
294 		}
295 		srq->rq.wq = wq;
296 		srq->rq.size = size;
297 		wq->head = n;
298 		wq->tail = 0;
299 		if (attr_mask & IB_SRQ_LIMIT)
300 			srq->limit = attr->srq_limit;
301 		spin_unlock_irq(&srq->rq.lock);
302 
303 		vfree(owq);
304 
305 		if (srq->ip) {
306 			struct qib_mmap_info *ip = srq->ip;
307 			struct qib_ibdev *dev = to_idev(srq->ibsrq.device);
308 			u32 s = sizeof(struct qib_rwq) + size * sz;
309 
310 			qib_update_mmap_info(dev, ip, s, wq);
311 
312 			/*
313 			 * Return the offset to mmap.
314 			 * See qib_mmap() for details.
315 			 */
316 			if (udata && udata->inlen >= sizeof(__u64)) {
317 				ret = ib_copy_to_udata(udata, &ip->offset,
318 						       sizeof(ip->offset));
319 				if (ret)
320 					goto bail;
321 			}
322 
323 			/*
324 			 * Put user mapping info onto the pending list
325 			 * unless it already is on the list.
326 			 */
327 			spin_lock_irq(&dev->pending_lock);
328 			if (list_empty(&ip->pending_mmaps))
329 				list_add(&ip->pending_mmaps,
330 					 &dev->pending_mmaps);
331 			spin_unlock_irq(&dev->pending_lock);
332 		}
333 	} else if (attr_mask & IB_SRQ_LIMIT) {
334 		spin_lock_irq(&srq->rq.lock);
335 		if (attr->srq_limit >= srq->rq.size)
336 			ret = -EINVAL;
337 		else
338 			srq->limit = attr->srq_limit;
339 		spin_unlock_irq(&srq->rq.lock);
340 	}
341 	goto bail;
342 
343 bail_unlock:
344 	spin_unlock_irq(&srq->rq.lock);
345 bail_free:
346 	vfree(wq);
347 bail:
348 	return ret;
349 }
350 
qib_query_srq(struct ib_srq * ibsrq,struct ib_srq_attr * attr)351 int qib_query_srq(struct ib_srq *ibsrq, struct ib_srq_attr *attr)
352 {
353 	struct qib_srq *srq = to_isrq(ibsrq);
354 
355 	attr->max_wr = srq->rq.size - 1;
356 	attr->max_sge = srq->rq.max_sge;
357 	attr->srq_limit = srq->limit;
358 	return 0;
359 }
360 
361 /**
362  * qib_destroy_srq - destroy a shared receive queue
363  * @ibsrq: the SRQ to destroy
364  */
qib_destroy_srq(struct ib_srq * ibsrq)365 int qib_destroy_srq(struct ib_srq *ibsrq)
366 {
367 	struct qib_srq *srq = to_isrq(ibsrq);
368 	struct qib_ibdev *dev = to_idev(ibsrq->device);
369 
370 	spin_lock(&dev->n_srqs_lock);
371 	dev->n_srqs_allocated--;
372 	spin_unlock(&dev->n_srqs_lock);
373 	if (srq->ip)
374 		kref_put(&srq->ip->ref, qib_release_mmap_info);
375 	else
376 		vfree(srq->rq.wq);
377 	kfree(srq);
378 
379 	return 0;
380 }
381