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_client_setup.h>
20 #include <drm/drm_drv.h>
21 #include <drm/drm_fbdev_shmem.h>
22 #include <drm/drm_file.h>
23 #include <drm/drm_gem_framebuffer_helper.h>
24 #include <drm/drm_ioctl.h>
25 #include <drm/drm_managed.h>
26 #include <drm/drm_probe_helper.h>
27 #include <drm/drm_gem_shmem_helper.h>
28 #include <drm/drm_vblank.h>
29
30 #include "vkms_drv.h"
31
32 #include <drm/drm_print.h>
33 #include <drm/drm_debugfs.h>
34
35 #define DRIVER_NAME "vkms"
36 #define DRIVER_DESC "Virtual Kernel Mode Setting"
37 #define DRIVER_DATE "20180514"
38 #define DRIVER_MAJOR 1
39 #define DRIVER_MINOR 0
40
41 static struct vkms_config *default_config;
42
43 static bool enable_cursor = true;
44 module_param_named(enable_cursor, enable_cursor, bool, 0444);
45 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
46
47 static bool enable_writeback = true;
48 module_param_named(enable_writeback, enable_writeback, bool, 0444);
49 MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support");
50
51 static bool enable_overlay;
52 module_param_named(enable_overlay, enable_overlay, bool, 0444);
53 MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");
54
55 DEFINE_DRM_GEM_FOPS(vkms_driver_fops);
56
vkms_release(struct drm_device * dev)57 static void vkms_release(struct drm_device *dev)
58 {
59 struct vkms_device *vkms = drm_device_to_vkms_device(dev);
60
61 if (vkms->output.composer_workq)
62 destroy_workqueue(vkms->output.composer_workq);
63 }
64
vkms_atomic_commit_tail(struct drm_atomic_state * old_state)65 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
66 {
67 struct drm_device *dev = old_state->dev;
68 struct drm_crtc *crtc;
69 struct drm_crtc_state *old_crtc_state;
70 int i;
71
72 drm_atomic_helper_commit_modeset_disables(dev, old_state);
73
74 drm_atomic_helper_commit_planes(dev, old_state, 0);
75
76 drm_atomic_helper_commit_modeset_enables(dev, old_state);
77
78 drm_atomic_helper_fake_vblank(old_state);
79
80 drm_atomic_helper_commit_hw_done(old_state);
81
82 drm_atomic_helper_wait_for_flip_done(dev, old_state);
83
84 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
85 struct vkms_crtc_state *vkms_state =
86 to_vkms_crtc_state(old_crtc_state);
87
88 flush_work(&vkms_state->composer_work);
89 }
90
91 drm_atomic_helper_cleanup_planes(dev, old_state);
92 }
93
vkms_config_show(struct seq_file * m,void * data)94 static int vkms_config_show(struct seq_file *m, void *data)
95 {
96 struct drm_debugfs_entry *entry = m->private;
97 struct drm_device *dev = entry->dev;
98 struct vkms_device *vkmsdev = drm_device_to_vkms_device(dev);
99
100 seq_printf(m, "writeback=%d\n", vkmsdev->config->writeback);
101 seq_printf(m, "cursor=%d\n", vkmsdev->config->cursor);
102 seq_printf(m, "overlay=%d\n", vkmsdev->config->overlay);
103
104 return 0;
105 }
106
107 static const struct drm_debugfs_info vkms_config_debugfs_list[] = {
108 { "vkms_config", vkms_config_show, 0 },
109 };
110
111 static const struct drm_driver vkms_driver = {
112 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
113 .release = vkms_release,
114 .fops = &vkms_driver_fops,
115 DRM_GEM_SHMEM_DRIVER_OPS,
116 DRM_FBDEV_SHMEM_DRIVER_OPS,
117
118 .name = DRIVER_NAME,
119 .desc = DRIVER_DESC,
120 .date = DRIVER_DATE,
121 .major = DRIVER_MAJOR,
122 .minor = DRIVER_MINOR,
123 };
124
vkms_atomic_check(struct drm_device * dev,struct drm_atomic_state * state)125 static int vkms_atomic_check(struct drm_device *dev, struct drm_atomic_state *state)
126 {
127 struct drm_crtc *crtc;
128 struct drm_crtc_state *new_crtc_state;
129 int i;
130
131 for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
132 if (!new_crtc_state->gamma_lut || !new_crtc_state->color_mgmt_changed)
133 continue;
134
135 if (new_crtc_state->gamma_lut->length / sizeof(struct drm_color_lut *)
136 > VKMS_LUT_SIZE)
137 return -EINVAL;
138 }
139
140 return drm_atomic_helper_check(dev, state);
141 }
142
143 static const struct drm_mode_config_funcs vkms_mode_funcs = {
144 .fb_create = drm_gem_fb_create,
145 .atomic_check = vkms_atomic_check,
146 .atomic_commit = drm_atomic_helper_commit,
147 };
148
149 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
150 .atomic_commit_tail = vkms_atomic_commit_tail,
151 };
152
vkms_modeset_init(struct vkms_device * vkmsdev)153 static int vkms_modeset_init(struct vkms_device *vkmsdev)
154 {
155 struct drm_device *dev = &vkmsdev->drm;
156 int ret;
157
158 ret = drmm_mode_config_init(dev);
159 if (ret)
160 return ret;
161
162 dev->mode_config.funcs = &vkms_mode_funcs;
163 dev->mode_config.min_width = XRES_MIN;
164 dev->mode_config.min_height = YRES_MIN;
165 dev->mode_config.max_width = XRES_MAX;
166 dev->mode_config.max_height = YRES_MAX;
167 dev->mode_config.cursor_width = 512;
168 dev->mode_config.cursor_height = 512;
169 /*
170 * FIXME: There's a confusion between bpp and depth between this and
171 * fbdev helpers. We have to go with 0, meaning "pick the default",
172 * which is XRGB8888 in all cases.
173 */
174 dev->mode_config.preferred_depth = 0;
175 dev->mode_config.helper_private = &vkms_mode_config_helpers;
176
177 return vkms_output_init(vkmsdev, 0);
178 }
179
vkms_create(struct vkms_config * config)180 static int vkms_create(struct vkms_config *config)
181 {
182 int ret;
183 struct platform_device *pdev;
184 struct vkms_device *vkms_device;
185
186 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
187 if (IS_ERR(pdev))
188 return PTR_ERR(pdev);
189
190 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
191 ret = -ENOMEM;
192 goto out_unregister;
193 }
194
195 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver,
196 struct vkms_device, drm);
197 if (IS_ERR(vkms_device)) {
198 ret = PTR_ERR(vkms_device);
199 goto out_devres;
200 }
201 vkms_device->platform = pdev;
202 vkms_device->config = config;
203 config->dev = vkms_device;
204
205 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
206 DMA_BIT_MASK(64));
207
208 if (ret) {
209 DRM_ERROR("Could not initialize DMA support\n");
210 goto out_devres;
211 }
212
213 ret = drm_vblank_init(&vkms_device->drm, 1);
214 if (ret) {
215 DRM_ERROR("Failed to vblank\n");
216 goto out_devres;
217 }
218
219 ret = vkms_modeset_init(vkms_device);
220 if (ret)
221 goto out_devres;
222
223 drm_debugfs_add_files(&vkms_device->drm, vkms_config_debugfs_list,
224 ARRAY_SIZE(vkms_config_debugfs_list));
225
226 ret = drm_dev_register(&vkms_device->drm, 0);
227 if (ret)
228 goto out_devres;
229
230 drm_client_setup(&vkms_device->drm, NULL);
231
232 return 0;
233
234 out_devres:
235 devres_release_group(&pdev->dev, NULL);
236 out_unregister:
237 platform_device_unregister(pdev);
238 return ret;
239 }
240
vkms_init(void)241 static int __init vkms_init(void)
242 {
243 int ret;
244 struct vkms_config *config;
245
246 config = kmalloc(sizeof(*config), GFP_KERNEL);
247 if (!config)
248 return -ENOMEM;
249
250 default_config = config;
251
252 config->cursor = enable_cursor;
253 config->writeback = enable_writeback;
254 config->overlay = enable_overlay;
255
256 ret = vkms_create(config);
257 if (ret)
258 kfree(config);
259
260 return ret;
261 }
262
vkms_destroy(struct vkms_config * config)263 static void vkms_destroy(struct vkms_config *config)
264 {
265 struct platform_device *pdev;
266
267 if (!config->dev) {
268 DRM_INFO("vkms_device is NULL.\n");
269 return;
270 }
271
272 pdev = config->dev->platform;
273
274 drm_dev_unregister(&config->dev->drm);
275 drm_atomic_helper_shutdown(&config->dev->drm);
276 devres_release_group(&pdev->dev, NULL);
277 platform_device_unregister(pdev);
278
279 config->dev = NULL;
280 }
281
vkms_exit(void)282 static void __exit vkms_exit(void)
283 {
284 if (default_config->dev)
285 vkms_destroy(default_config);
286
287 kfree(default_config);
288 }
289
290 module_init(vkms_init);
291 module_exit(vkms_exit);
292
293 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
294 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
295 MODULE_DESCRIPTION(DRIVER_DESC);
296 MODULE_LICENSE("GPL");
297