tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0+
2
3/**
4 * DOC: vkms (Virtual Kernel Modesetting)
5 *
6 * VKMS is a software-only model of a KMS driver that is useful for testing
7 * and for running X (or similar) on headless machines. VKMS aims to enable
8 * a virtual display with no need of a hardware display capability, releasing
9 * the GPU in DRM API tests.
10 */
11
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/dma-mapping.h>
15
16#include <drm/drm_gem.h>
17#include <drm/drm_atomic.h>
18#include <drm/drm_atomic_helper.h>
19#include <drm/drm_drv.h>
20#include <drm/drm_fbdev_generic.h>
21#include <drm/drm_file.h>
22#include <drm/drm_gem_framebuffer_helper.h>
23#include <drm/drm_ioctl.h>
24#include <drm/drm_managed.h>
25#include <drm/drm_probe_helper.h>
26#include <drm/drm_gem_shmem_helper.h>
27#include <drm/drm_vblank.h>
28
29#include "vkms_drv.h"
30
31#include <drm/drm_print.h>
32#include <drm/drm_debugfs.h>
33
34#define DRIVER_NAME "vkms"
35#define DRIVER_DESC "Virtual Kernel Mode Setting"
36#define DRIVER_DATE "20180514"
37#define DRIVER_MAJOR 1
38#define DRIVER_MINOR 0
39
40static struct vkms_config *default_config;
41
42static bool enable_cursor = true;
43module_param_named(enable_cursor, enable_cursor, bool, 0444);
44MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
45
46static bool enable_writeback = true;
47module_param_named(enable_writeback, enable_writeback, bool, 0444);
48MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support");
49
50static bool enable_overlay;
51module_param_named(enable_overlay, enable_overlay, bool, 0444);
52MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");
53
54DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
55
56static void vkms_release(struct drm_device *dev)
57{
58 struct vkms_device *vkms = drm_device_to_vkms_device(dev);
59
60 if (vkms->output.composer_workq)
61 destroy_workqueue(vkms->output.composer_workq);
62}
63
64static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
65{
66 struct drm_device *dev = old_state->dev;
67 struct drm_crtc *crtc;
68 struct drm_crtc_state *old_crtc_state;
69 int i;
70
71 drm_atomic_helper_commit_modeset_disables(dev, old_state);
72
73 drm_atomic_helper_commit_planes(dev, old_state, 0);
74
75 drm_atomic_helper_commit_modeset_enables(dev, old_state);
76
77 drm_atomic_helper_fake_vblank(old_state);
78
79 drm_atomic_helper_commit_hw_done(old_state);
80
81 drm_atomic_helper_wait_for_flip_done(dev, old_state);
82
83 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
84 struct vkms_crtc_state *vkms_state =
85 to_vkms_crtc_state(old_crtc_state);
86
87 flush_work(&vkms_state->composer_work);
88 }
89
90 drm_atomic_helper_cleanup_planes(dev, old_state);
91}
92
93static int vkms_config_show(struct seq_file *m, void *data)
94{
95 struct drm_debugfs_entry *entry = m->private;
96 struct drm_device *dev = entry->dev;
97 struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
98
99 seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback);
100 seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor);
101 seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay);
102
103 return 0;
104}
105
106static const struct drm_debugfs_info vkms_config_debugfs_list[] = {
107 { "vkms_config", vkms_config_show, 0 },
108};
109
110static const struct drm_driver vkms_driver = {
111 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
112 .release = vkms_release,
113 .fops = &vkms_driver_fops,
114 DRM_GEM_SHMEM_DRIVER_OPS,
115
116 .name = DRIVER_NAME,
117 .desc = DRIVER_DESC,
118 .date = DRIVER_DATE,
119 .major = DRIVER_MAJOR,
120 .minor = DRIVER_MINOR,
121};
122
123static const struct drm_mode_config_funcs vkms_mode_funcs = {
124 .fb_create = drm_gem_fb_create,
125 .atomic_check = drm_atomic_helper_check,
126 .atomic_commit = drm_atomic_helper_commit,
127};
128
129static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
130 .atomic_commit_tail = vkms_atomic_commit_tail,
131};
132
133static int vkms_modeset_init(struct vkms_device *vkmsdev)
134{
135 struct drm_device *dev = &vkmsdev->drm;
136 int ret;
137
138 ret = drmm_mode_config_init(dev);
139 if (ret)
140 return ret;
141
142 dev->mode_config.funcs = &vkms_mode_funcs;
143 dev->mode_config.min_width = XRES_MIN;
144 dev->mode_config.min_height = YRES_MIN;
145 dev->mode_config.max_width = XRES_MAX;
146 dev->mode_config.max_height = YRES_MAX;
147 dev->mode_config.cursor_width = 512;
148 dev->mode_config.cursor_height = 512;
149 /* FIXME: There's a confusion between bpp and depth between this and
150 * fbdev helpers. We have to go with 0, meaning "pick the default",
151 * which ix XRGB8888 in all cases. */
152 dev->mode_config.preferred_depth = 0;
153 dev->mode_config.helper_private = &vkms_mode_config_helpers;
154
155 return vkms_output_init(vkmsdev, 0);
156}
157
158static int vkms_create(struct vkms_config *config)
159{
160 int ret;
161 struct platform_device *pdev;
162 struct vkms_device *vkms_device;
163
164 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
165 if (IS_ERR(pdev))
166 return PTR_ERR(pdev);
167
168 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
169 ret = -ENOMEM;
170 goto out_unregister;
171 }
172
173 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
174 struct vkms_device, drm);
175 if (IS_ERR(vkms_device)) {
176 ret = PTR_ERR(vkms_device);
177 goto out_devres;
178 }
179 vkms_device->platform = pdev;
180 vkms_device->config = config;
181 config->dev = vkms_device;
182
183 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
184 DMA_BIT_MASK(64));
185
186 if (ret) {
187 DRM_ERROR("Could not initialize DMA support\n");
188 goto out_devres;
189 }
190
191 ret = drm_vblank_init(&vkms_device->drm, 1);
192 if (ret) {
193 DRM_ERROR("Failed to vblank\n");
194 goto out_devres;
195 }
196
197 ret = vkms_modeset_init(vkms_device);
198 if (ret)
199 goto out_devres;
200
201 drm_debugfs_add_files(&vkms_device->drm, vkms_config_debugfs_list,
202 ARRAY_SIZE(vkms_config_debugfs_list));
203
204 ret = drm_dev_register(&vkms_device->drm, 0);
205 if (ret)
206 goto out_devres;
207
208 drm_fbdev_generic_setup(&vkms_device->drm, 0);
209
210 return 0;
211
212out_devres:
213 devres_release_group(&pdev->dev, NULL);
214out_unregister:
215 platform_device_unregister(pdev);
216 return ret;
217}
218
219static int __init vkms_init(void)
220{
221 int ret;
222 struct vkms_config *config;
223
224 config = kmalloc(sizeof(*config), GFP_KERNEL);
225 if (!config)
226 return -ENOMEM;
227
228 default_config = config;
229
230 config->cursor = enable_cursor;
231 config->writeback = enable_writeback;
232 config->overlay = enable_overlay;
233
234 ret = vkms_create(config);
235 if (ret)
236 kfree(config);
237
238 return ret;
239}
240
241static void vkms_destroy(struct vkms_config *config)
242{
243 struct platform_device *pdev;
244
245 if (!config->dev) {
246 DRM_INFO("vkms_device is NULL.\n");
247 return;
248 }
249
250 pdev = config->dev->platform;
251
252 drm_dev_unregister(&config->dev->drm);
253 drm_atomic_helper_shutdown(&config->dev->drm);
254 devres_release_group(&pdev->dev, NULL);
255 platform_device_unregister(pdev);
256
257 config->dev = NULL;
258}
259
260static void __exit vkms_exit(void)
261{
262 if (default_config->dev)
263 vkms_destroy(default_config);
264
265 kfree(default_config);
266}
267
268module_init(vkms_init);
269module_exit(vkms_exit);
270
271MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
272MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
273MODULE_DESCRIPTION(DRIVER_DESC);
274MODULE_LICENSE("GPL");