1 /*
2  * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
3  * Copyright (c) 2015 System Fabric Works, 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 retailuce 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/vmalloc.h>
35 #include "rxe.h"
36 #include "rxe_loc.h"
37 #include "rxe_queue.h"
38 
39 int do_mmap_info(struct rxe_dev *rxe,
40 		 struct mminfo __user *outbuf,
41 		 struct ib_ucontext *context,
42 		 struct rxe_queue_buf *buf,
43 		 size_t buf_size,
44 		 struct rxe_mmap_info **ip_p)
45 {
46 	int err;
47 	struct rxe_mmap_info *ip = NULL;
48 
49 	if (outbuf) {
50 		ip = rxe_create_mmap_info(rxe, buf_size, context, buf);
51 		if (!ip)
52 			goto err1;
53 
54 		err = copy_to_user(outbuf, &ip->info, sizeof(ip->info));
55 		if (err)
56 			goto err2;
57 
58 		spin_lock_bh(&rxe->pending_lock);
59 		list_add(&ip->pending_mmaps, &rxe->pending_mmaps);
60 		spin_unlock_bh(&rxe->pending_lock);
61 	}
62 
63 	*ip_p = ip;
64 
65 	return 0;
66 
67 err2:
68 	kfree(ip);
69 err1:
70 	return -EINVAL;
71 }
72 
73 inline void rxe_queue_reset(struct rxe_queue *q)
74 {
75 	/* queue is comprised from header and the memory
76 	 * of the actual queue. See "struct rxe_queue_buf" in rxe_queue.h
77 	 * reset only the queue itself and not the management header
78 	 */
79 	memset(q->buf->data, 0, q->buf_size - sizeof(struct rxe_queue_buf));
80 }
81 
82 struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
83 				 int *num_elem,
84 				 unsigned int elem_size)
85 {
86 	struct rxe_queue *q;
87 	size_t buf_size;
88 	unsigned int num_slots;
89 
90 	/* num_elem == 0 is allowed, but uninteresting */
91 	if (*num_elem < 0)
92 		goto err1;
93 
94 	q = kmalloc(sizeof(*q), GFP_KERNEL);
95 	if (!q)
96 		goto err1;
97 
98 	q->rxe = rxe;
99 
100 	/* used in resize, only need to copy used part of queue */
101 	q->elem_size = elem_size;
102 
103 	/* pad element up to at least a cacheline and always a power of 2 */
104 	if (elem_size < cache_line_size())
105 		elem_size = cache_line_size();
106 	elem_size = roundup_pow_of_two(elem_size);
107 
108 	q->log2_elem_size = order_base_2(elem_size);
109 
110 	num_slots = *num_elem + 1;
111 	num_slots = roundup_pow_of_two(num_slots);
112 	q->index_mask = num_slots - 1;
113 
114 	buf_size = sizeof(struct rxe_queue_buf) + num_slots * elem_size;
115 
116 	q->buf = vmalloc_user(buf_size);
117 	if (!q->buf)
118 		goto err2;
119 
120 	q->buf->log2_elem_size = q->log2_elem_size;
121 	q->buf->index_mask = q->index_mask;
122 
123 	q->buf_size = buf_size;
124 
125 	*num_elem = num_slots - 1;
126 	return q;
127 
128 err2:
129 	kfree(q);
130 err1:
131 	return NULL;
132 }
133 
134 /* copies elements from original q to new q and then swaps the contents of the
135  * two q headers. This is so that if anyone is holding a pointer to q it will
136  * still work
137  */
138 static int resize_finish(struct rxe_queue *q, struct rxe_queue *new_q,
139 			 unsigned int num_elem)
140 {
141 	if (!queue_empty(q) && (num_elem < queue_count(q)))
142 		return -EINVAL;
143 
144 	while (!queue_empty(q)) {
145 		memcpy(producer_addr(new_q), consumer_addr(q),
146 		       new_q->elem_size);
147 		advance_producer(new_q);
148 		advance_consumer(q);
149 	}
150 
151 	swap(*q, *new_q);
152 
153 	return 0;
154 }
155 
156 int rxe_queue_resize(struct rxe_queue *q,
157 		     unsigned int *num_elem_p,
158 		     unsigned int elem_size,
159 		     struct ib_ucontext *context,
160 		     struct mminfo __user *outbuf,
161 		     spinlock_t *producer_lock,
162 		     spinlock_t *consumer_lock)
163 {
164 	struct rxe_queue *new_q;
165 	unsigned int num_elem = *num_elem_p;
166 	int err;
167 	unsigned long flags = 0, flags1;
168 
169 	new_q = rxe_queue_init(q->rxe, &num_elem, elem_size);
170 	if (!new_q)
171 		return -ENOMEM;
172 
173 	err = do_mmap_info(new_q->rxe, outbuf, context, new_q->buf,
174 			   new_q->buf_size, &new_q->ip);
175 	if (err) {
176 		vfree(new_q->buf);
177 		kfree(new_q);
178 		goto err1;
179 	}
180 
181 	spin_lock_irqsave(consumer_lock, flags1);
182 
183 	if (producer_lock) {
184 		spin_lock_irqsave(producer_lock, flags);
185 		err = resize_finish(q, new_q, num_elem);
186 		spin_unlock_irqrestore(producer_lock, flags);
187 	} else {
188 		err = resize_finish(q, new_q, num_elem);
189 	}
190 
191 	spin_unlock_irqrestore(consumer_lock, flags1);
192 
193 	rxe_queue_cleanup(new_q);	/* new/old dep on err */
194 	if (err)
195 		goto err1;
196 
197 	*num_elem_p = num_elem;
198 	return 0;
199 
200 err1:
201 	return err;
202 }
203 
204 void rxe_queue_cleanup(struct rxe_queue *q)
205 {
206 	if (q->ip)
207 		kref_put(&q->ip->ref, rxe_mmap_release);
208 	else
209 		vfree(q->buf);
210 
211 	kfree(q);
212 }
213