1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Video4Linux2 generic ISP parameters and statistics support
4 *
5 * Copyright (C) 2025 Ideas On Board Oy
6 * Author: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
7 */
8
9 #include <media/v4l2-isp.h>
10
11 #include <linux/bitops.h>
12 #include <linux/device.h>
13
14 #include <media/videobuf2-core.h>
15
v4l2_isp_params_validate_buffer_size(struct device * dev,struct vb2_buffer * vb,size_t max_size)16 int v4l2_isp_params_validate_buffer_size(struct device *dev,
17 struct vb2_buffer *vb,
18 size_t max_size)
19 {
20 size_t header_size = offsetof(struct v4l2_isp_params_buffer, data);
21 size_t payload_size = vb2_get_plane_payload(vb, 0);
22
23 /* Payload size can't be greater than the destination buffer size */
24 if (payload_size > max_size) {
25 dev_dbg(dev, "Payload size is too large: %zu\n", payload_size);
26 return -EINVAL;
27 }
28
29 /* Payload size can't be smaller than the header size */
30 if (payload_size < header_size) {
31 dev_dbg(dev, "Payload size is too small: %zu\n", payload_size);
32 return -EINVAL;
33 }
34
35 return 0;
36 }
37 EXPORT_SYMBOL_GPL(v4l2_isp_params_validate_buffer_size);
38
v4l2_isp_params_validate_buffer(struct device * dev,struct vb2_buffer * vb,const struct v4l2_isp_params_buffer * buffer,const struct v4l2_isp_params_block_type_info * type_info,size_t num_block_types)39 int v4l2_isp_params_validate_buffer(struct device *dev, struct vb2_buffer *vb,
40 const struct v4l2_isp_params_buffer *buffer,
41 const struct v4l2_isp_params_block_type_info *type_info,
42 size_t num_block_types)
43 {
44 size_t header_size = offsetof(struct v4l2_isp_params_buffer, data);
45 size_t payload_size = vb2_get_plane_payload(vb, 0);
46 size_t block_offset = 0;
47 size_t buffer_size;
48
49 /*
50 * Currently only the first version of the V4L2 ISP parameters format is
51 * supported. We accept both V0 and V1 to support existing drivers
52 * compatible with V4L2 ISP that use either 0 or 1 as their "first
53 * version" identifiers.
54 */
55 if (buffer->version != V4L2_ISP_PARAMS_VERSION_V0 &&
56 buffer->version != V4L2_ISP_PARAMS_VERSION_V1) {
57 dev_dbg(dev,
58 "Unsupported V4L2 ISP parameters format version: %u\n",
59 buffer->version);
60 return -EINVAL;
61 }
62
63 /* Validate the size reported in the header */
64 buffer_size = header_size + buffer->data_size;
65 if (buffer_size != payload_size) {
66 dev_dbg(dev, "Data size %zu and payload size %zu are different\n",
67 buffer_size, payload_size);
68 return -EINVAL;
69 }
70
71 /* Walk the list of ISP configuration blocks and validate them. */
72 buffer_size = buffer->data_size;
73 while (buffer_size >= sizeof(struct v4l2_isp_params_block_header)) {
74 const struct v4l2_isp_params_block_type_info *info;
75 const struct v4l2_isp_params_block_header *block;
76
77 block = (const struct v4l2_isp_params_block_header *)
78 (buffer->data + block_offset);
79
80 if (block->type >= num_block_types) {
81 dev_dbg(dev,
82 "Invalid block type %u at offset %zu\n",
83 block->type, block_offset);
84 return -EINVAL;
85 }
86
87 if (block->size > buffer_size) {
88 dev_dbg(dev, "Premature end of parameters data\n");
89 return -EINVAL;
90 }
91
92 /* It's invalid to specify both ENABLE and DISABLE. */
93 if ((block->flags & (V4L2_ISP_PARAMS_FL_BLOCK_ENABLE |
94 V4L2_ISP_PARAMS_FL_BLOCK_DISABLE)) ==
95 (V4L2_ISP_PARAMS_FL_BLOCK_ENABLE |
96 V4L2_ISP_PARAMS_FL_BLOCK_DISABLE)) {
97 dev_dbg(dev, "Invalid block flags %x at offset %zu\n",
98 block->flags, block_offset);
99 return -EINVAL;
100 }
101
102 /*
103 * Match the block reported size against the type info provided
104 * one, but allow the block to only contain the header in
105 * case it is going to be disabled.
106 */
107 info = &type_info[block->type];
108 if (block->size != info->size &&
109 (!(block->flags & V4L2_ISP_PARAMS_FL_BLOCK_DISABLE) ||
110 block->size != sizeof(*block))) {
111 dev_dbg(dev,
112 "Invalid block size %u (expected %zu) at offset %zu\n",
113 block->size, info->size, block_offset);
114 return -EINVAL;
115 }
116
117 block_offset += block->size;
118 buffer_size -= block->size;
119 }
120
121 if (buffer_size) {
122 dev_dbg(dev, "Unexpected data after the parameters buffer end\n");
123 return -EINVAL;
124 }
125
126 return 0;
127 }
128 EXPORT_SYMBOL_GPL(v4l2_isp_params_validate_buffer);
129
130 MODULE_LICENSE("GPL");
131 MODULE_AUTHOR("Jacopo Mondi <jacopo.mondi@ideasonboard.com");
132 MODULE_DESCRIPTION("V4L2 generic ISP parameters and statistics helpers");
133