1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * drm kms/fb cma (contiguous memory allocator) 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_cma_helper.h>
14 #include <drm/drm_fourcc.h>
15 #include <drm/drm_framebuffer.h>
16 #include <drm/drm_gem_cma_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 cma helper functions
24 *
25 * Provides helper functions for creating a cma (contiguous memory allocator)
26 * backed framebuffer.
27 *
28 * drm_gem_fb_create() is used in the &drm_mode_config_funcs.fb_create
29 * callback function to create a cma backed framebuffer.
30 */
31
32 /**
33 * drm_fb_cma_get_gem_obj() - Get CMA GEM object for framebuffer
34 * @fb: The framebuffer
35 * @plane: Which plane
36 *
37 * Return the CMA GEM object for given framebuffer.
38 *
39 * This function will usually be called from the CRTC callback functions.
40 */
drm_fb_cma_get_gem_obj(struct drm_framebuffer * fb,unsigned int plane)41 struct drm_gem_cma_object *drm_fb_cma_get_gem_obj(struct drm_framebuffer *fb,
42 unsigned int plane)
43 {
44 struct drm_gem_object *gem;
45
46 gem = drm_gem_fb_get_obj(fb, plane);
47 if (!gem)
48 return NULL;
49
50 return to_drm_gem_cma_obj(gem);
51 }
52 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_obj);
53
54 /**
55 * drm_fb_cma_get_gem_addr() - Get physical address for framebuffer, for pixel
56 * formats where values are grouped in blocks this will get you the beginning of
57 * the block
58 * @fb: The framebuffer
59 * @state: Which state of drm plane
60 * @plane: Which plane
61 * Return the CMA GEM address for given framebuffer.
62 *
63 * This function will usually be called from the PLANE callback functions.
64 */
drm_fb_cma_get_gem_addr(struct drm_framebuffer * fb,struct drm_plane_state * state,unsigned int plane)65 dma_addr_t drm_fb_cma_get_gem_addr(struct drm_framebuffer *fb,
66 struct drm_plane_state *state,
67 unsigned int plane)
68 {
69 struct drm_gem_cma_object *obj;
70 dma_addr_t paddr;
71 u8 h_div = 1, v_div = 1;
72 u32 block_w = drm_format_info_block_width(fb->format, plane);
73 u32 block_h = drm_format_info_block_height(fb->format, plane);
74 u32 block_size = fb->format->char_per_block[plane];
75 u32 sample_x;
76 u32 sample_y;
77 u32 block_start_y;
78 u32 num_hblocks;
79
80 obj = drm_fb_cma_get_gem_obj(fb, plane);
81 if (!obj)
82 return 0;
83
84 paddr = obj->paddr + fb->offsets[plane];
85
86 if (plane > 0) {
87 h_div = fb->format->hsub;
88 v_div = fb->format->vsub;
89 }
90
91 sample_x = (state->src_x >> 16) / h_div;
92 sample_y = (state->src_y >> 16) / v_div;
93 block_start_y = (sample_y / block_h) * block_h;
94 num_hblocks = sample_x / block_w;
95
96 paddr += fb->pitches[plane] * block_start_y;
97 paddr += block_size * num_hblocks;
98
99 return paddr;
100 }
101 EXPORT_SYMBOL_GPL(drm_fb_cma_get_gem_addr);
102
103 /**
104 * drm_fb_cma_sync_non_coherent - Sync GEM object to non-coherent backing
105 * memory
106 * @drm: DRM device
107 * @old_state: Old plane state
108 * @state: New plane state
109 *
110 * This function can be used by drivers that use damage clips and have
111 * CMA GEM objects backed by non-coherent memory. Calling this function
112 * in a plane's .atomic_update ensures that all the data in the backing
113 * memory have been written to RAM.
114 */
drm_fb_cma_sync_non_coherent(struct drm_device * drm,struct drm_plane_state * old_state,struct drm_plane_state * state)115 void drm_fb_cma_sync_non_coherent(struct drm_device *drm,
116 struct drm_plane_state *old_state,
117 struct drm_plane_state *state)
118 {
119 const struct drm_format_info *finfo = state->fb->format;
120 struct drm_atomic_helper_damage_iter iter;
121 const struct drm_gem_cma_object *cma_obj;
122 unsigned int offset, i;
123 struct drm_rect clip;
124 dma_addr_t daddr;
125 size_t nb_bytes;
126
127 for (i = 0; i < finfo->num_planes; i++) {
128 cma_obj = drm_fb_cma_get_gem_obj(state->fb, i);
129 if (!cma_obj->map_noncoherent)
130 continue;
131
132 daddr = drm_fb_cma_get_gem_addr(state->fb, state, i);
133 drm_atomic_helper_damage_iter_init(&iter, old_state, state);
134
135 drm_atomic_for_each_plane_damage(&iter, &clip) {
136 /* Ignore x1/x2 values, invalidate complete lines */
137 offset = clip.y1 * state->fb->pitches[i];
138
139 nb_bytes = (clip.y2 - clip.y1) * state->fb->pitches[i];
140 dma_sync_single_for_device(drm->dev, daddr + offset,
141 nb_bytes, DMA_TO_DEVICE);
142 }
143 }
144 }
145 EXPORT_SYMBOL_GPL(drm_fb_cma_sync_non_coherent);
146