Moni Shoua | 8700e3e | 2016-06-16 16:45:23 +0300 | [diff] [blame] | 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 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 | */ |
| 58 | struct 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 | |
| 69 | struct 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 | |
| 79 | int do_mmap_info(struct rxe_dev *rxe, |
Jason Gunthorpe | 0c43ab3 | 2018-03-13 16:33:18 -0600 | [diff] [blame] | 80 | struct mminfo __user *outbuf, |
Moni Shoua | 8700e3e | 2016-06-16 16:45:23 +0300 | [diff] [blame] | 81 | struct ib_ucontext *context, |
| 82 | struct rxe_queue_buf *buf, |
| 83 | size_t buf_size, |
| 84 | struct rxe_mmap_info **ip_p); |
| 85 | |
Yonatan Cohen | aa75b07 | 2016-11-16 10:39:17 +0200 | [diff] [blame] | 86 | void rxe_queue_reset(struct rxe_queue *q); |
| 87 | |
Moni Shoua | 8700e3e | 2016-06-16 16:45:23 +0300 | [diff] [blame] | 88 | struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe, |
| 89 | int *num_elem, |
| 90 | unsigned int elem_size); |
| 91 | |
| 92 | int rxe_queue_resize(struct rxe_queue *q, |
| 93 | unsigned int *num_elem_p, |
| 94 | unsigned int elem_size, |
| 95 | struct ib_ucontext *context, |
Jason Gunthorpe | 0c43ab3 | 2018-03-13 16:33:18 -0600 | [diff] [blame] | 96 | struct mminfo __user *outbuf, |
Moni Shoua | 8700e3e | 2016-06-16 16:45:23 +0300 | [diff] [blame] | 97 | /* Protect producers while resizing queue */ |
| 98 | spinlock_t *producer_lock, |
| 99 | /* Protect consumers while resizing queue */ |
| 100 | spinlock_t *consumer_lock); |
| 101 | |
| 102 | void rxe_queue_cleanup(struct rxe_queue *queue); |
| 103 | |
| 104 | static inline int next_index(struct rxe_queue *q, int index) |
| 105 | { |
| 106 | return (index + 1) & q->buf->index_mask; |
| 107 | } |
| 108 | |
| 109 | static 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 | |
| 115 | static 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 | |
| 121 | static 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 | |
| 127 | static 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 | |
| 133 | static 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 | |
| 139 | static 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 | |
| 145 | static inline unsigned int producer_index(struct rxe_queue *q) |
| 146 | { |
| 147 | return q->buf->producer_index; |
| 148 | } |
| 149 | |
| 150 | static inline unsigned int consumer_index(struct rxe_queue *q) |
| 151 | { |
| 152 | return q->buf->consumer_index; |
| 153 | } |
| 154 | |
| 155 | static 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 | |
| 161 | static 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 | |
| 168 | static 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 | |
| 174 | static 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 */ |