blob: 79ba4b320054b4e53cfd377fec70eea42e68bb37 [file] [log] [blame]
Moni Shoua8700e3e2016-06-16 16:45:23 +03001/*
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 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#ifndef RXE_QUEUE_H
35#define RXE_QUEUE_H
36
37/* implements a simple circular buffer that can optionally be
38 * shared between user space and the kernel and can be resized
39
40 * the requested element size is rounded up to a power of 2
41 * and the number of elements in the buffer is also rounded
42 * up to a power of 2. Since the queue is empty when the
43 * producer and consumer indices match the maximum capacity
44 * of the queue is one less than the number of element slots
45 */
46
47/* this data structure is shared between user space and kernel
48 * space for those cases where the queue is shared. It contains
49 * the producer and consumer indices. Is also contains a copy
50 * of the queue size parameters for user space to use but the
51 * kernel must use the parameters in the rxe_queue struct
52 * this MUST MATCH the corresponding librxe struct
53 * for performance reasons arrange to have producer and consumer
54 * pointers in separate cache lines
55 * the kernel should always mask the indices to avoid accessing
56 * memory outside of the data area
57 */
58struct rxe_queue_buf {
59 __u32 log2_elem_size;
60 __u32 index_mask;
61 __u32 pad_1[30];
62 __u32 producer_index;
63 __u32 pad_2[31];
64 __u32 consumer_index;
65 __u32 pad_3[31];
66 __u8 data[0];
67};
68
69struct rxe_queue {
70 struct rxe_dev *rxe;
71 struct rxe_queue_buf *buf;
72 struct rxe_mmap_info *ip;
73 size_t buf_size;
74 size_t elem_size;
75 unsigned int log2_elem_size;
76 unsigned int index_mask;
77};
78
79int do_mmap_info(struct rxe_dev *rxe,
Jason Gunthorpe0c43ab32018-03-13 16:33:18 -060080 struct mminfo __user *outbuf,
Moni Shoua8700e3e2016-06-16 16:45:23 +030081 struct ib_ucontext *context,
82 struct rxe_queue_buf *buf,
83 size_t buf_size,
84 struct rxe_mmap_info **ip_p);
85
Yonatan Cohenaa75b072016-11-16 10:39:17 +020086void rxe_queue_reset(struct rxe_queue *q);
87
Moni Shoua8700e3e2016-06-16 16:45:23 +030088struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe,
89 int *num_elem,
90 unsigned int elem_size);
91
92int rxe_queue_resize(struct rxe_queue *q,
93 unsigned int *num_elem_p,
94 unsigned int elem_size,
95 struct ib_ucontext *context,
Jason Gunthorpe0c43ab32018-03-13 16:33:18 -060096 struct mminfo __user *outbuf,
Moni Shoua8700e3e2016-06-16 16:45:23 +030097 /* Protect producers while resizing queue */
98 spinlock_t *producer_lock,
99 /* Protect consumers while resizing queue */
100 spinlock_t *consumer_lock);
101
102void rxe_queue_cleanup(struct rxe_queue *queue);
103
104static inline int next_index(struct rxe_queue *q, int index)
105{
106 return (index + 1) & q->buf->index_mask;
107}
108
109static inline int queue_empty(struct rxe_queue *q)
110{
111 return ((q->buf->producer_index - q->buf->consumer_index)
112 & q->index_mask) == 0;
113}
114
115static inline int queue_full(struct rxe_queue *q)
116{
117 return ((q->buf->producer_index + 1 - q->buf->consumer_index)
118 & q->index_mask) == 0;
119}
120
121static inline void advance_producer(struct rxe_queue *q)
122{
123 q->buf->producer_index = (q->buf->producer_index + 1)
124 & q->index_mask;
125}
126
127static inline void advance_consumer(struct rxe_queue *q)
128{
129 q->buf->consumer_index = (q->buf->consumer_index + 1)
130 & q->index_mask;
131}
132
133static inline void *producer_addr(struct rxe_queue *q)
134{
135 return q->buf->data + ((q->buf->producer_index & q->index_mask)
136 << q->log2_elem_size);
137}
138
139static inline void *consumer_addr(struct rxe_queue *q)
140{
141 return q->buf->data + ((q->buf->consumer_index & q->index_mask)
142 << q->log2_elem_size);
143}
144
145static inline unsigned int producer_index(struct rxe_queue *q)
146{
147 return q->buf->producer_index;
148}
149
150static inline unsigned int consumer_index(struct rxe_queue *q)
151{
152 return q->buf->consumer_index;
153}
154
155static inline void *addr_from_index(struct rxe_queue *q, unsigned int index)
156{
157 return q->buf->data + ((index & q->index_mask)
158 << q->buf->log2_elem_size);
159}
160
161static inline unsigned int index_from_addr(const struct rxe_queue *q,
162 const void *addr)
163{
164 return (((u8 *)addr - q->buf->data) >> q->log2_elem_size)
165 & q->index_mask;
166}
167
168static inline unsigned int queue_count(const struct rxe_queue *q)
169{
170 return (q->buf->producer_index - q->buf->consumer_index)
171 & q->index_mask;
172}
173
174static inline void *queue_head(struct rxe_queue *q)
175{
176 return queue_empty(q) ? NULL : consumer_addr(q);
177}
178
179#endif /* RXE_QUEUE_H */