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