diff options
Diffstat (limited to 'drivers/infiniband/sw/rxe/rxe_queue.h')
| -rw-r--r-- | drivers/infiniband/sw/rxe/rxe_queue.h | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_queue.h b/drivers/infiniband/sw/rxe/rxe_queue.h new file mode 100644 index 000000000..79ba4b320 --- /dev/null +++ b/drivers/infiniband/sw/rxe/rxe_queue.h @@ -0,0 +1,179 @@ +/* + * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved. + * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +#ifndef RXE_QUEUE_H +#define RXE_QUEUE_H + +/* implements a simple circular buffer that can optionally be + * shared between user space and the kernel and can be resized + + * the requested element size is rounded up to a power of 2 + * and the number of elements in the buffer is also rounded + * up to a power of 2. Since the queue is empty when the + * producer and consumer indices match the maximum capacity + * of the queue is one less than the number of element slots + */ + +/* this data structure is shared between user space and kernel + * space for those cases where the queue is shared. It contains + * the producer and consumer indices. Is also contains a copy + * of the queue size parameters for user space to use but the + * kernel must use the parameters in the rxe_queue struct + * this MUST MATCH the corresponding librxe struct + * for performance reasons arrange to have producer and consumer + * pointers in separate cache lines + * the kernel should always mask the indices to avoid accessing + * memory outside of the data area + */ +struct rxe_queue_buf { + __u32 log2_elem_size; + __u32 index_mask; + __u32 pad_1[30]; + __u32 producer_index; + __u32 pad_2[31]; + __u32 consumer_index; + __u32 pad_3[31]; + __u8 data[0]; +}; + +struct rxe_queue { + struct rxe_dev *rxe; + struct rxe_queue_buf *buf; + struct rxe_mmap_info *ip; + size_t buf_size; + size_t elem_size; + unsigned int log2_elem_size; + unsigned int index_mask; +}; + +int do_mmap_info(struct rxe_dev *rxe, + struct mminfo __user *outbuf, + struct ib_ucontext *context, + struct rxe_queue_buf *buf, + size_t buf_size, + struct rxe_mmap_info **ip_p); + +void rxe_queue_reset(struct rxe_queue *q); + +struct rxe_queue *rxe_queue_init(struct rxe_dev *rxe, + int *num_elem, + unsigned int elem_size); + +int rxe_queue_resize(struct rxe_queue *q, + unsigned int *num_elem_p, + unsigned int elem_size, + struct ib_ucontext *context, + struct mminfo __user *outbuf, + /* Protect producers while resizing queue */ + spinlock_t *producer_lock, + /* Protect consumers while resizing queue */ + spinlock_t *consumer_lock); + +void rxe_queue_cleanup(struct rxe_queue *queue); + +static inline int next_index(struct rxe_queue *q, int index) +{ + return (index + 1) & q->buf->index_mask; +} + +static inline int queue_empty(struct rxe_queue *q) +{ + return ((q->buf->producer_index - q->buf->consumer_index) + & q->index_mask) == 0; +} + +static inline int queue_full(struct rxe_queue *q) +{ + return ((q->buf->producer_index + 1 - q->buf->consumer_index) + & q->index_mask) == 0; +} + +static inline void advance_producer(struct rxe_queue *q) +{ + q->buf->producer_index = (q->buf->producer_index + 1) + & q->index_mask; +} + +static inline void advance_consumer(struct rxe_queue *q) +{ + q->buf->consumer_index = (q->buf->consumer_index + 1) + & q->index_mask; +} + +static inline void *producer_addr(struct rxe_queue *q) +{ + return q->buf->data + ((q->buf->producer_index & q->index_mask) + << q->log2_elem_size); +} + +static inline void *consumer_addr(struct rxe_queue *q) +{ + return q->buf->data + ((q->buf->consumer_index & q->index_mask) + << q->log2_elem_size); +} + +static inline unsigned int producer_index(struct rxe_queue *q) +{ + return q->buf->producer_index; +} + +static inline unsigned int consumer_index(struct rxe_queue *q) +{ + return q->buf->consumer_index; +} + +static inline void *addr_from_index(struct rxe_queue *q, unsigned int index) +{ + return q->buf->data + ((index & q->index_mask) + << q->buf->log2_elem_size); +} + +static inline unsigned int index_from_addr(const struct rxe_queue *q, + const void *addr) +{ + return (((u8 *)addr - q->buf->data) >> q->log2_elem_size) + & q->index_mask; +} + +static inline unsigned int queue_count(const struct rxe_queue *q) +{ + return (q->buf->producer_index - q->buf->consumer_index) + & q->index_mask; +} + +static inline void *queue_head(struct rxe_queue *q) +{ + return queue_empty(q) ? NULL : consumer_addr(q); +} + +#endif /* RXE_QUEUE_H */ |