hinic3_queue_common.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2/* Copyright (c) Huawei Technologies Co., Ltd. 2025. All rights reserved. */
 3
 4#ifndef _HINIC3_QUEUE_COMMON_H_
 5#define _HINIC3_QUEUE_COMMON_H_
 6
 7#include <linux/types.h>
 8
 9#include "hinic3_common.h"
10
11struct hinic3_hwdev;
12
13struct hinic3_queue_pages {
14	/* Array of DMA-able pages that actually holds the queue entries. */
15	struct hinic3_dma_addr_align  *pages;
16	/* Page size in bytes. */
17	u32                           page_size;
18	/* Number of pages, must be power of 2. */
19	u16                           num_pages;
20	u8                            elem_size_shift;
21	u8                            elem_per_pg_shift;
22};
23
24void hinic3_queue_pages_init(struct hinic3_queue_pages *qpages, u32 q_depth,
25			     u32 page_size, u32 elem_size);
26int hinic3_queue_pages_alloc(struct hinic3_hwdev *hwdev,
27			     struct hinic3_queue_pages *qpages, u32 align);
28void hinic3_queue_pages_free(struct hinic3_hwdev *hwdev,
29			     struct hinic3_queue_pages *qpages);
30
31/* Get pointer to queue entry at the specified index. Index does not have to be
32 * masked to queue depth, only least significant bits will be used. Also
33 * provides remaining elements in same page (including the first one) in case
34 * caller needs multiple entries.
35 */
36static inline void *get_q_element(const struct hinic3_queue_pages *qpages,
37				  u32 idx, u32 *remaining_in_page)
38{
39	const struct hinic3_dma_addr_align *page;
40	u32 page_idx, elem_idx, elem_per_pg, ofs;
41	u8 shift;
42
43	shift = qpages->elem_per_pg_shift;
44	page_idx = (idx >> shift) & (qpages->num_pages - 1);
45	elem_per_pg = 1 << shift;
46	elem_idx = idx & (elem_per_pg - 1);
47	if (remaining_in_page)
48		*remaining_in_page = elem_per_pg - elem_idx;
49	ofs = elem_idx << qpages->elem_size_shift;
50	page = qpages->pages + page_idx;
51	return (char *)page->align_vaddr + ofs;
52}
53
54#endif