xref: /linux/drivers/net/ethernet/huawei/hinic3/hinic3_queue_common.h (revision ab93e0dd72c37d378dd936f031ffb83ff2bd87ce)
1*17fcb3dcSFan Gong /* SPDX-License-Identifier: GPL-2.0 */
2*17fcb3dcSFan Gong /* Copyright (c) Huawei Technologies Co., Ltd. 2025. All rights reserved. */
3*17fcb3dcSFan Gong 
4*17fcb3dcSFan Gong #ifndef _HINIC3_QUEUE_COMMON_H_
5*17fcb3dcSFan Gong #define _HINIC3_QUEUE_COMMON_H_
6*17fcb3dcSFan Gong 
7*17fcb3dcSFan Gong #include <linux/types.h>
8*17fcb3dcSFan Gong 
9*17fcb3dcSFan Gong #include "hinic3_common.h"
10*17fcb3dcSFan Gong 
11*17fcb3dcSFan Gong struct hinic3_hwdev;
12*17fcb3dcSFan Gong 
13*17fcb3dcSFan Gong struct hinic3_queue_pages {
14*17fcb3dcSFan Gong 	/* Array of DMA-able pages that actually holds the queue entries. */
15*17fcb3dcSFan Gong 	struct hinic3_dma_addr_align  *pages;
16*17fcb3dcSFan Gong 	/* Page size in bytes. */
17*17fcb3dcSFan Gong 	u32                           page_size;
18*17fcb3dcSFan Gong 	/* Number of pages, must be power of 2. */
19*17fcb3dcSFan Gong 	u16                           num_pages;
20*17fcb3dcSFan Gong 	u8                            elem_size_shift;
21*17fcb3dcSFan Gong 	u8                            elem_per_pg_shift;
22*17fcb3dcSFan Gong };
23*17fcb3dcSFan Gong 
24*17fcb3dcSFan Gong void hinic3_queue_pages_init(struct hinic3_queue_pages *qpages, u32 q_depth,
25*17fcb3dcSFan Gong 			     u32 page_size, u32 elem_size);
26*17fcb3dcSFan Gong int hinic3_queue_pages_alloc(struct hinic3_hwdev *hwdev,
27*17fcb3dcSFan Gong 			     struct hinic3_queue_pages *qpages, u32 align);
28*17fcb3dcSFan Gong void hinic3_queue_pages_free(struct hinic3_hwdev *hwdev,
29*17fcb3dcSFan Gong 			     struct hinic3_queue_pages *qpages);
30*17fcb3dcSFan Gong 
31*17fcb3dcSFan Gong /* Get pointer to queue entry at the specified index. Index does not have to be
32*17fcb3dcSFan Gong  * masked to queue depth, only least significant bits will be used. Also
33*17fcb3dcSFan Gong  * provides remaining elements in same page (including the first one) in case
34*17fcb3dcSFan Gong  * caller needs multiple entries.
35*17fcb3dcSFan Gong  */
36*17fcb3dcSFan Gong static inline void *get_q_element(const struct hinic3_queue_pages *qpages,
37*17fcb3dcSFan Gong 				  u32 idx, u32 *remaining_in_page)
38*17fcb3dcSFan Gong {
39*17fcb3dcSFan Gong 	const struct hinic3_dma_addr_align *page;
40*17fcb3dcSFan Gong 	u32 page_idx, elem_idx, elem_per_pg, ofs;
41*17fcb3dcSFan Gong 	u8 shift;
42*17fcb3dcSFan Gong 
43*17fcb3dcSFan Gong 	shift = qpages->elem_per_pg_shift;
44*17fcb3dcSFan Gong 	page_idx = (idx >> shift) & (qpages->num_pages - 1);
45*17fcb3dcSFan Gong 	elem_per_pg = 1 << shift;
46*17fcb3dcSFan Gong 	elem_idx = idx & (elem_per_pg - 1);
47*17fcb3dcSFan Gong 	if (remaining_in_page)
48*17fcb3dcSFan Gong 		*remaining_in_page = elem_per_pg - elem_idx;
49*17fcb3dcSFan Gong 	ofs = elem_idx << qpages->elem_size_shift;
50*17fcb3dcSFan Gong 	page = qpages->pages + page_idx;
51*17fcb3dcSFan Gong 	return (char *)page->align_vaddr + ofs;
52*17fcb3dcSFan Gong }
53*17fcb3dcSFan Gong 
54*17fcb3dcSFan Gong #endif
55