xref: /linux/drivers/infiniband/hw/ionic/ionic_queue.c (revision 6093a688a07da07808f0122f9aa2a3eed250d853)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2018-2025, Advanced Micro Devices, Inc. */
3 
4 #include <linux/dma-mapping.h>
5 
6 #include "ionic_queue.h"
7 
8 int ionic_queue_init(struct ionic_queue *q, struct device *dma_dev,
9 		     int depth, size_t stride)
10 {
11 	if (depth < 0 || depth > 0xffff)
12 		return -EINVAL;
13 
14 	if (stride == 0 || stride > 0x10000)
15 		return -EINVAL;
16 
17 	if (depth == 0)
18 		depth = 1;
19 
20 	q->depth_log2 = order_base_2(depth + 1);
21 	q->stride_log2 = order_base_2(stride);
22 
23 	if (q->depth_log2 + q->stride_log2 < PAGE_SHIFT)
24 		q->depth_log2 = PAGE_SHIFT - q->stride_log2;
25 
26 	if (q->depth_log2 > 16 || q->stride_log2 > 16)
27 		return -EINVAL;
28 
29 	q->size = BIT_ULL(q->depth_log2 + q->stride_log2);
30 	q->mask = BIT(q->depth_log2) - 1;
31 
32 	q->ptr = dma_alloc_coherent(dma_dev, q->size, &q->dma, GFP_KERNEL);
33 	if (!q->ptr)
34 		return -ENOMEM;
35 
36 	/* it will always be page aligned, but just to be sure... */
37 	if (!PAGE_ALIGNED(q->ptr)) {
38 		dma_free_coherent(dma_dev, q->size, q->ptr, q->dma);
39 		return -ENOMEM;
40 	}
41 
42 	q->prod = 0;
43 	q->cons = 0;
44 	q->dbell = 0;
45 
46 	return 0;
47 }
48 
49 void ionic_queue_destroy(struct ionic_queue *q, struct device *dma_dev)
50 {
51 	dma_free_coherent(dma_dev, q->size, q->ptr, q->dma);
52 }
53