ionic_queue.c

 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
 8int 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
49void 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}