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315 lines
7.8 KiB
315 lines
7.8 KiB
/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */ |
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/* |
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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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#ifndef RXE_QUEUE_H |
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#define RXE_QUEUE_H |
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/* for definition of shared struct rxe_queue_buf */ |
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#include <uapi/rdma/rdma_user_rxe.h> |
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|
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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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* Notes: |
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* - Kernel space indices are always masked off to q->index_mask |
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* before storing so do not need to be checked on reads. |
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* - User space indices may be out of range and must be |
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* masked before use when read. |
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* - The kernel indices for shared queues must not be written |
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* by user space so a local copy is used and a shared copy is |
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* stored when the local copy changes. |
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* - By passing the type in the parameter list separate from q |
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* the compiler can eliminate the switch statement when the |
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* actual queue type is known when the function is called. |
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* In the performance path this is done. In less critical |
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* paths just q->type is passed. |
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*/ |
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/* type of queue */ |
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enum queue_type { |
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QUEUE_TYPE_KERNEL, |
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QUEUE_TYPE_TO_USER, |
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QUEUE_TYPE_FROM_USER, |
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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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u32 index_mask; |
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enum queue_type type; |
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/* private copy of index for shared queues between |
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* kernel space and user space. Kernel reads and writes |
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* this copy and then replicates to rxe_queue_buf |
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* for read access by user space. |
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*/ |
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u32 index; |
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}; |
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int do_mmap_info(struct rxe_dev *rxe, struct mminfo __user *outbuf, |
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struct ib_udata *udata, struct rxe_queue_buf *buf, |
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size_t buf_size, 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, int *num_elem, |
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unsigned int elem_size, enum queue_type type); |
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int rxe_queue_resize(struct rxe_queue *q, unsigned int *num_elem_p, |
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unsigned int elem_size, struct ib_udata *udata, |
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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, enum queue_type type) |
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{ |
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u32 prod; |
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u32 cons; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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/* protect user space index */ |
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prod = smp_load_acquire(&q->buf->producer_index); |
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cons = q->index; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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prod = q->index; |
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/* protect user space index */ |
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cons = smp_load_acquire(&q->buf->consumer_index); |
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break; |
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case QUEUE_TYPE_KERNEL: |
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prod = q->buf->producer_index; |
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cons = q->buf->consumer_index; |
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break; |
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} |
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return ((prod - cons) & q->index_mask) == 0; |
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} |
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static inline int queue_full(struct rxe_queue *q, enum queue_type type) |
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{ |
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u32 prod; |
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u32 cons; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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/* protect user space index */ |
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prod = smp_load_acquire(&q->buf->producer_index); |
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cons = q->index; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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prod = q->index; |
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/* protect user space index */ |
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cons = smp_load_acquire(&q->buf->consumer_index); |
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break; |
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case QUEUE_TYPE_KERNEL: |
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prod = q->buf->producer_index; |
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cons = q->buf->consumer_index; |
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break; |
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} |
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return ((prod + 1 - cons) & q->index_mask) == 0; |
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} |
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static inline unsigned int queue_count(const struct rxe_queue *q, |
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enum queue_type type) |
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{ |
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u32 prod; |
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u32 cons; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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/* protect user space index */ |
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prod = smp_load_acquire(&q->buf->producer_index); |
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cons = q->index; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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prod = q->index; |
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/* protect user space index */ |
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cons = smp_load_acquire(&q->buf->consumer_index); |
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break; |
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case QUEUE_TYPE_KERNEL: |
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prod = q->buf->producer_index; |
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cons = q->buf->consumer_index; |
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break; |
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} |
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return (prod - cons) & q->index_mask; |
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} |
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static inline void advance_producer(struct rxe_queue *q, enum queue_type type) |
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{ |
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u32 prod; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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pr_warn_once("Normally kernel should not write user space index\n"); |
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/* protect user space index */ |
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prod = smp_load_acquire(&q->buf->producer_index); |
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prod = (prod + 1) & q->index_mask; |
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/* same */ |
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smp_store_release(&q->buf->producer_index, prod); |
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break; |
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case QUEUE_TYPE_TO_USER: |
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prod = q->index; |
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q->index = (prod + 1) & q->index_mask; |
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q->buf->producer_index = q->index; |
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break; |
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case QUEUE_TYPE_KERNEL: |
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prod = q->buf->producer_index; |
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q->buf->producer_index = (prod + 1) & q->index_mask; |
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break; |
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} |
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} |
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static inline void advance_consumer(struct rxe_queue *q, enum queue_type type) |
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{ |
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u32 cons; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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cons = q->index; |
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q->index = (cons + 1) & q->index_mask; |
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q->buf->consumer_index = q->index; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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pr_warn_once("Normally kernel should not write user space index\n"); |
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/* protect user space index */ |
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cons = smp_load_acquire(&q->buf->consumer_index); |
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cons = (cons + 1) & q->index_mask; |
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/* same */ |
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smp_store_release(&q->buf->consumer_index, cons); |
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break; |
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case QUEUE_TYPE_KERNEL: |
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cons = q->buf->consumer_index; |
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q->buf->consumer_index = (cons + 1) & q->index_mask; |
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break; |
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} |
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} |
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static inline void *producer_addr(struct rxe_queue *q, enum queue_type type) |
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{ |
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u32 prod; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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/* protect user space index */ |
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prod = smp_load_acquire(&q->buf->producer_index); |
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prod &= q->index_mask; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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prod = q->index; |
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break; |
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case QUEUE_TYPE_KERNEL: |
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prod = q->buf->producer_index; |
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break; |
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} |
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return q->buf->data + (prod << q->log2_elem_size); |
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} |
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static inline void *consumer_addr(struct rxe_queue *q, enum queue_type type) |
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{ |
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u32 cons; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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cons = q->index; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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/* protect user space index */ |
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cons = smp_load_acquire(&q->buf->consumer_index); |
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cons &= q->index_mask; |
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break; |
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case QUEUE_TYPE_KERNEL: |
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cons = q->buf->consumer_index; |
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break; |
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} |
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return q->buf->data + (cons << 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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enum queue_type type) |
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{ |
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u32 prod; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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/* protect user space index */ |
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prod = smp_load_acquire(&q->buf->producer_index); |
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prod &= q->index_mask; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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prod = q->index; |
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break; |
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case QUEUE_TYPE_KERNEL: |
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prod = q->buf->producer_index; |
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break; |
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} |
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return prod; |
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} |
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static inline unsigned int consumer_index(struct rxe_queue *q, |
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enum queue_type type) |
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{ |
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u32 cons; |
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switch (type) { |
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case QUEUE_TYPE_FROM_USER: |
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cons = q->index; |
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break; |
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case QUEUE_TYPE_TO_USER: |
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/* protect user space index */ |
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cons = smp_load_acquire(&q->buf->consumer_index); |
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cons &= q->index_mask; |
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break; |
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case QUEUE_TYPE_KERNEL: |
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cons = q->buf->consumer_index; |
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break; |
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} |
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return cons; |
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} |
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static inline void *addr_from_index(struct rxe_queue *q, |
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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 void *queue_head(struct rxe_queue *q, enum queue_type type) |
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{ |
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return queue_empty(q, type) ? NULL : consumer_addr(q, type); |
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} |
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#endif /* RXE_QUEUE_H */
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