1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * drm kms/fb dma helper functions |
4 | * |
5 | * Copyright (C) 2012 Analog Devices Inc. |
6 | * Author: Lars-Peter Clausen <lars@metafoo.de> |
7 | * |
8 | * Based on udl_fbdev.c |
9 | * Copyright (C) 2012 Red Hat |
10 | */ |
11 | |
12 | #include <drm/drm_damage_helper.h> |
13 | #include <drm/drm_fb_dma_helper.h> |
14 | #include <drm/drm_fourcc.h> |
15 | #include <drm/drm_framebuffer.h> |
16 | #include <drm/drm_gem_dma_helper.h> |
17 | #include <drm/drm_gem_framebuffer_helper.h> |
18 | #include <drm/drm_plane.h> |
19 | #include <linux/dma-mapping.h> |
20 | #include <linux/module.h> |
21 | |
22 | /** |
23 | * DOC: framebuffer dma helper functions |
24 | * |
25 | * Provides helper functions for creating a DMA-contiguous framebuffer. |
26 | * |
27 | * Depending on the platform, the buffers may be physically non-contiguous and |
28 | * mapped through an IOMMU or a similar mechanism, or allocated from |
29 | * physically-contiguous memory (using, for instance, CMA or a pool of memory |
30 | * reserved at early boot). This is handled behind the scenes by the DMA mapping |
31 | * API. |
32 | * |
33 | * drm_gem_fb_create() is used in the &drm_mode_config_funcs.fb_create |
34 | * callback function to create a DMA-contiguous framebuffer. |
35 | */ |
36 | |
37 | /** |
38 | * drm_fb_dma_get_gem_obj() - Get DMA GEM object for framebuffer |
39 | * @fb: The framebuffer |
40 | * @plane: Which plane |
41 | * |
42 | * Return the DMA GEM object for given framebuffer. |
43 | * |
44 | * This function will usually be called from the CRTC callback functions. |
45 | */ |
46 | struct drm_gem_dma_object *drm_fb_dma_get_gem_obj(struct drm_framebuffer *fb, |
47 | unsigned int plane) |
48 | { |
49 | struct drm_gem_object *gem; |
50 | |
51 | gem = drm_gem_fb_get_obj(fb, plane); |
52 | if (!gem) |
53 | return NULL; |
54 | |
55 | return to_drm_gem_dma_obj(gem); |
56 | } |
57 | EXPORT_SYMBOL_GPL(drm_fb_dma_get_gem_obj); |
58 | |
59 | /** |
60 | * drm_fb_dma_get_gem_addr() - Get DMA (bus) address for framebuffer, for pixel |
61 | * formats where values are grouped in blocks this will get you the beginning of |
62 | * the block |
63 | * @fb: The framebuffer |
64 | * @state: Which state of drm plane |
65 | * @plane: Which plane |
66 | * Return the DMA GEM address for given framebuffer. |
67 | * |
68 | * This function will usually be called from the PLANE callback functions. |
69 | */ |
70 | dma_addr_t drm_fb_dma_get_gem_addr(struct drm_framebuffer *fb, |
71 | struct drm_plane_state *state, |
72 | unsigned int plane) |
73 | { |
74 | struct drm_gem_dma_object *obj; |
75 | dma_addr_t dma_addr; |
76 | u8 h_div = 1, v_div = 1; |
77 | u32 block_w = drm_format_info_block_width(info: fb->format, plane); |
78 | u32 block_h = drm_format_info_block_height(info: fb->format, plane); |
79 | u32 block_size = fb->format->char_per_block[plane]; |
80 | u32 sample_x; |
81 | u32 sample_y; |
82 | u32 block_start_y; |
83 | u32 num_hblocks; |
84 | |
85 | obj = drm_fb_dma_get_gem_obj(fb, plane); |
86 | if (!obj) |
87 | return 0; |
88 | |
89 | dma_addr = obj->dma_addr + fb->offsets[plane]; |
90 | |
91 | if (plane > 0) { |
92 | h_div = fb->format->hsub; |
93 | v_div = fb->format->vsub; |
94 | } |
95 | |
96 | sample_x = (state->src_x >> 16) / h_div; |
97 | sample_y = (state->src_y >> 16) / v_div; |
98 | block_start_y = (sample_y / block_h) * block_h; |
99 | num_hblocks = sample_x / block_w; |
100 | |
101 | dma_addr += fb->pitches[plane] * block_start_y; |
102 | dma_addr += block_size * num_hblocks; |
103 | |
104 | return dma_addr; |
105 | } |
106 | EXPORT_SYMBOL_GPL(drm_fb_dma_get_gem_addr); |
107 | |
108 | /** |
109 | * drm_fb_dma_sync_non_coherent - Sync GEM object to non-coherent backing |
110 | * memory |
111 | * @drm: DRM device |
112 | * @old_state: Old plane state |
113 | * @state: New plane state |
114 | * |
115 | * This function can be used by drivers that use damage clips and have |
116 | * DMA GEM objects backed by non-coherent memory. Calling this function |
117 | * in a plane's .atomic_update ensures that all the data in the backing |
118 | * memory have been written to RAM. |
119 | */ |
120 | void drm_fb_dma_sync_non_coherent(struct drm_device *drm, |
121 | struct drm_plane_state *old_state, |
122 | struct drm_plane_state *state) |
123 | { |
124 | const struct drm_format_info *finfo = state->fb->format; |
125 | struct drm_atomic_helper_damage_iter iter; |
126 | const struct drm_gem_dma_object *dma_obj; |
127 | unsigned int offset, i; |
128 | struct drm_rect clip; |
129 | dma_addr_t daddr; |
130 | size_t nb_bytes; |
131 | |
132 | for (i = 0; i < finfo->num_planes; i++) { |
133 | dma_obj = drm_fb_dma_get_gem_obj(state->fb, i); |
134 | if (!dma_obj->map_noncoherent) |
135 | continue; |
136 | |
137 | daddr = drm_fb_dma_get_gem_addr(state->fb, state, i); |
138 | drm_atomic_helper_damage_iter_init(iter: &iter, old_state, new_state: state); |
139 | |
140 | drm_atomic_for_each_plane_damage(&iter, &clip) { |
141 | /* Ignore x1/x2 values, invalidate complete lines */ |
142 | offset = clip.y1 * state->fb->pitches[i]; |
143 | |
144 | nb_bytes = (clip.y2 - clip.y1) * state->fb->pitches[i]; |
145 | dma_sync_single_for_device(dev: drm->dev, addr: daddr + offset, |
146 | size: nb_bytes, dir: DMA_TO_DEVICE); |
147 | } |
148 | } |
149 | } |
150 | EXPORT_SYMBOL_GPL(drm_fb_dma_sync_non_coherent); |
151 | |