shadow_queue.h

  1/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
  2/*
  3 * Copyright (c) 2024, Microsoft Corporation. All rights reserved.
  4 */
  5
  6#ifndef _MANA_SHADOW_QUEUE_H_
  7#define _MANA_SHADOW_QUEUE_H_
  8
  9struct shadow_wqe_header {
 10	u16 opcode;
 11	u16 error_code;
 12	u32 posted_wqe_size;
 13	u64 wr_id;
 14};
 15
 16struct ud_rq_shadow_wqe {
 17	struct shadow_wqe_header header;
 18	u32 byte_len;
 19	u32 src_qpn;
 20};
 21
 22struct ud_sq_shadow_wqe {
 23	struct shadow_wqe_header header;
 24};
 25
 26struct shadow_queue {
 27	/* Unmasked producer index, Incremented on wqe posting */
 28	u64 prod_idx;
 29	/* Unmasked consumer index, Incremented on cq polling */
 30	u64 cons_idx;
 31	/* Unmasked index of next-to-complete (from HW) shadow WQE */
 32	u64 next_to_complete_idx;
 33	/* queue size in wqes */
 34	u32 length;
 35	/* distance between elements in bytes */
 36	u32 stride;
 37	/* ring buffer holding wqes */
 38	void *buffer;
 39};
 40
 41static inline int create_shadow_queue(struct shadow_queue *queue, uint32_t length, uint32_t stride)
 42{
 43	queue->buffer = kvmalloc_array(length, stride, GFP_KERNEL);
 44	if (!queue->buffer)
 45		return -ENOMEM;
 46
 47	queue->length = length;
 48	queue->stride = stride;
 49
 50	return 0;
 51}
 52
 53static inline void destroy_shadow_queue(struct shadow_queue *queue)
 54{
 55	kvfree(queue->buffer);
 56}
 57
 58static inline bool shadow_queue_full(struct shadow_queue *queue)
 59{
 60	return (queue->prod_idx - queue->cons_idx) >= queue->length;
 61}
 62
 63static inline bool shadow_queue_empty(struct shadow_queue *queue)
 64{
 65	return queue->prod_idx == queue->cons_idx;
 66}
 67
 68static inline void *
 69shadow_queue_get_element(const struct shadow_queue *queue, u64 unmasked_index)
 70{
 71	u32 index = unmasked_index % queue->length;
 72
 73	return ((u8 *)queue->buffer + index * queue->stride);
 74}
 75
 76static inline void *
 77shadow_queue_producer_entry(struct shadow_queue *queue)
 78{
 79	return shadow_queue_get_element(queue, queue->prod_idx);
 80}
 81
 82static inline void *
 83shadow_queue_get_next_to_consume(const struct shadow_queue *queue)
 84{
 85	if (queue->cons_idx == queue->next_to_complete_idx)
 86		return NULL;
 87
 88	return shadow_queue_get_element(queue, queue->cons_idx);
 89}
 90
 91static inline void *
 92shadow_queue_get_next_to_complete(struct shadow_queue *queue)
 93{
 94	if (queue->next_to_complete_idx == queue->prod_idx)
 95		return NULL;
 96
 97	return shadow_queue_get_element(queue, queue->next_to_complete_idx);
 98}
 99
100static inline void shadow_queue_advance_producer(struct shadow_queue *queue)
101{
102	queue->prod_idx++;
103}
104
105static inline void shadow_queue_advance_consumer(struct shadow_queue *queue)
106{
107	queue->cons_idx++;
108}
109
110static inline void shadow_queue_advance_next_to_complete(struct shadow_queue *queue)
111{
112	queue->next_to_complete_idx++;
113}
114
115#endif