1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Intel Corporation
3
4#include <linux/device.h>
5
6#include "ipu3.h"
7#include "ipu3-css-pool.h"
8#include "ipu3-dmamap.h"
9
10int imgu_css_dma_buffer_resize(struct imgu_device *imgu,
11 struct imgu_css_map *map, size_t size)
12{
13 if (map->size < size && map->vaddr) {
14 dev_warn(&imgu->pci_dev->dev, "dma buf resized from %zu to %zu",
15 map->size, size);
16
17 imgu_dmamap_free(imgu, map);
18 if (!imgu_dmamap_alloc(imgu, map, len: size))
19 return -ENOMEM;
20 }
21
22 return 0;
23}
24
25void imgu_css_pool_cleanup(struct imgu_device *imgu, struct imgu_css_pool *pool)
26{
27 unsigned int i;
28
29 for (i = 0; i < IPU3_CSS_POOL_SIZE; i++)
30 imgu_dmamap_free(imgu, map: &pool->entry[i].param);
31}
32
33int imgu_css_pool_init(struct imgu_device *imgu, struct imgu_css_pool *pool,
34 size_t size)
35{
36 unsigned int i;
37
38 for (i = 0; i < IPU3_CSS_POOL_SIZE; i++) {
39 pool->entry[i].valid = false;
40 if (size == 0) {
41 pool->entry[i].param.vaddr = NULL;
42 continue;
43 }
44
45 if (!imgu_dmamap_alloc(imgu, map: &pool->entry[i].param, len: size))
46 goto fail;
47 }
48
49 pool->last = IPU3_CSS_POOL_SIZE;
50
51 return 0;
52
53fail:
54 imgu_css_pool_cleanup(imgu, pool);
55 return -ENOMEM;
56}
57
58/*
59 * Allocate a new parameter via recycling the oldest entry in the pool.
60 */
61void imgu_css_pool_get(struct imgu_css_pool *pool)
62{
63 /* Get the oldest entry */
64 u32 n = (pool->last + 1) % IPU3_CSS_POOL_SIZE;
65
66 pool->entry[n].valid = true;
67 pool->last = n;
68}
69
70/*
71 * Undo, for all practical purposes, the effect of pool_get().
72 */
73void imgu_css_pool_put(struct imgu_css_pool *pool)
74{
75 pool->entry[pool->last].valid = false;
76 pool->last = (pool->last + IPU3_CSS_POOL_SIZE - 1) % IPU3_CSS_POOL_SIZE;
77}
78
79/**
80 * imgu_css_pool_last - Retrieve the nth pool entry from last
81 *
82 * @pool: a pointer to &struct imgu_css_pool.
83 * @n: the distance to the last index.
84 *
85 * Returns:
86 * The nth entry from last or null map to indicate no frame stored.
87 */
88const struct imgu_css_map *
89imgu_css_pool_last(struct imgu_css_pool *pool, unsigned int n)
90{
91 static const struct imgu_css_map null_map = { 0 };
92 int i = (pool->last + IPU3_CSS_POOL_SIZE - n) % IPU3_CSS_POOL_SIZE;
93
94 WARN_ON(n >= IPU3_CSS_POOL_SIZE);
95
96 if (!pool->entry[i].valid)
97 return &null_map;
98
99 return &pool->entry[i].param;
100}
101

source code of linux/drivers/staging/media/ipu3/ipu3-css-pool.c