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_fb_helper.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_vblank.h>
27
28#include "vkms_drv.h"
29
30#define DRIVER_NAME "vkms"
31#define DRIVER_DESC "Virtual Kernel Mode Setting"
32#define DRIVER_DATE "20180514"
33#define DRIVER_MAJOR 1
34#define DRIVER_MINOR 0
35
36static struct vkms_device *vkms_device;
37
38bool enable_cursor = true;
39module_param_named(enable_cursor, enable_cursor, bool, 0444);
40MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
41
42static const struct file_operations vkms_driver_fops = {
43 .owner = THIS_MODULE,
44 .open = drm_open,
45 .mmap = drm_gem_mmap,
46 .unlocked_ioctl = drm_ioctl,
47 .compat_ioctl = drm_compat_ioctl,
48 .poll = drm_poll,
49 .read = drm_read,
50 .llseek = no_llseek,
51 .release = drm_release,
52};
53
54static const struct vm_operations_struct vkms_gem_vm_ops = {
55 .fault = vkms_gem_fault,
56 .open = drm_gem_vm_open,
57 .close = drm_gem_vm_close,
58};
59
60static void vkms_release(struct drm_device *dev)
61{
62 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
63
64 platform_device_unregister(vkms->platform);
65 drm_atomic_helper_shutdown(&vkms->drm);
66 drm_mode_config_cleanup(&vkms->drm);
67 destroy_workqueue(vkms->output.composer_workq);
68}
69
70static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state)
71{
72 struct drm_device *dev = old_state->dev;
73 struct drm_crtc *crtc;
74 struct drm_crtc_state *old_crtc_state;
75 int i;
76
77 drm_atomic_helper_commit_modeset_disables(dev, old_state);
78
79 drm_atomic_helper_commit_planes(dev, old_state, 0);
80
81 drm_atomic_helper_commit_modeset_enables(dev, old_state);
82
83 drm_atomic_helper_fake_vblank(old_state);
84
85 drm_atomic_helper_commit_hw_done(old_state);
86
87 drm_atomic_helper_wait_for_flip_done(dev, old_state);
88
89 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {
90 struct vkms_crtc_state *vkms_state =
91 to_vkms_crtc_state(old_crtc_state);
92
93 flush_work(&vkms_state->composer_work);
94 }
95
96 drm_atomic_helper_cleanup_planes(dev, old_state);
97}
98
99static struct drm_driver vkms_driver = {
100 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM,
101 .release = vkms_release,
102 .fops = &vkms_driver_fops,
103 .dumb_create = vkms_dumb_create,
104 .gem_vm_ops = &vkms_gem_vm_ops,
105 .gem_free_object_unlocked = vkms_gem_free_object,
106 .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
107 .gem_prime_import_sg_table = vkms_prime_import_sg_table,
108
109 .name = DRIVER_NAME,
110 .desc = DRIVER_DESC,
111 .date = DRIVER_DATE,
112 .major = DRIVER_MAJOR,
113 .minor = DRIVER_MINOR,
114};
115
116static const struct drm_mode_config_funcs vkms_mode_funcs = {
117 .fb_create = drm_gem_fb_create,
118 .atomic_check = drm_atomic_helper_check,
119 .atomic_commit = drm_atomic_helper_commit,
120};
121
122static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
123 .atomic_commit_tail = vkms_atomic_commit_tail,
124};
125
126static int vkms_modeset_init(struct vkms_device *vkmsdev)
127{
128 struct drm_device *dev = &vkmsdev->drm;
129
130 drm_mode_config_init(dev);
131 dev->mode_config.funcs = &vkms_mode_funcs;
132 dev->mode_config.min_width = XRES_MIN;
133 dev->mode_config.min_height = YRES_MIN;
134 dev->mode_config.max_width = XRES_MAX;
135 dev->mode_config.max_height = YRES_MAX;
136 dev->mode_config.preferred_depth = 24;
137 dev->mode_config.helper_private = &vkms_mode_config_helpers;
138
139 return vkms_output_init(vkmsdev, 0);
140}
141
142static int __init vkms_init(void)
143{
144 int ret;
145
146 vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
147 if (!vkms_device)
148 return -ENOMEM;
149
150 vkms_device->platform =
151 platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
152 if (IS_ERR(vkms_device->platform)) {
153 ret = PTR_ERR(vkms_device->platform);
154 goto out_free;
155 }
156
157 ret = drm_dev_init(&vkms_device->drm, &vkms_driver,
158 &vkms_device->platform->dev);
159 if (ret)
160 goto out_unregister;
161 drmm_add_final_kfree(&vkms_device->drm, vkms_device);
162
163 ret = dma_coerce_mask_and_coherent(vkms_device->drm.dev,
164 DMA_BIT_MASK(64));
165
166 if (ret) {
167 DRM_ERROR("Could not initialize DMA support\n");
168 goto out_put;
169 }
170
171 vkms_device->drm.irq_enabled = true;
172
173 ret = drm_vblank_init(&vkms_device->drm, 1);
174 if (ret) {
175 DRM_ERROR("Failed to vblank\n");
176 goto out_put;
177 }
178
179 ret = vkms_modeset_init(vkms_device);
180 if (ret)
181 goto out_put;
182
183 ret = drm_dev_register(&vkms_device->drm, 0);
184 if (ret)
185 goto out_put;
186
187 return 0;
188
189out_put:
190 drm_dev_put(&vkms_device->drm);
191 return ret;
192
193out_unregister:
194 platform_device_unregister(vkms_device->platform);
195out_free:
196 kfree(vkms_device);
197 return ret;
198}
199
200static void __exit vkms_exit(void)
201{
202 if (!vkms_device) {
203 DRM_INFO("vkms_device is NULL.\n");
204 return;
205 }
206
207 drm_dev_unregister(&vkms_device->drm);
208 drm_dev_put(&vkms_device->drm);
209}
210
211module_init(vkms_init);
212module_exit(vkms_exit);
213
214MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>");
215MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>");
216MODULE_DESCRIPTION(DRIVER_DESC);
217MODULE_LICENSE("GPL");