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 * or for running X (or similar) on headless machines and be able to still 8 * use the GPU. vkms aims to enable a virtual display without the need for 9 * a hardware display capability. 10 */ 11 12 #include <linux/module.h> 13 #include <linux/platform_device.h> 14 15 #include <drm/drm_atomic.h> 16 #include <drm/drm_atomic_helper.h> 17 #include <drm/drm_drv.h> 18 #include <drm/drm_fb_helper.h> 19 #include <drm/drm_file.h> 20 #include <drm/drm_gem.h> 21 #include <drm/drm_gem_framebuffer_helper.h> 22 #include <drm/drm_ioctl.h> 23 #include <drm/drm_probe_helper.h> 24 #include <drm/drm_vblank.h> 25 26 #include "vkms_drv.h" 27 28 #define DRIVER_NAME "vkms" 29 #define DRIVER_DESC "Virtual Kernel Mode Setting" 30 #define DRIVER_DATE "20180514" 31 #define DRIVER_MAJOR 1 32 #define DRIVER_MINOR 0 33 34 static struct vkms_device *vkms_device; 35 36 bool enable_cursor; 37 module_param_named(enable_cursor, enable_cursor, bool, 0444); 38 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support"); 39 40 static const struct file_operations vkms_driver_fops = { 41 .owner = THIS_MODULE, 42 .open = drm_open, 43 .mmap = drm_gem_mmap, 44 .unlocked_ioctl = drm_ioctl, 45 .compat_ioctl = drm_compat_ioctl, 46 .poll = drm_poll, 47 .read = drm_read, 48 .llseek = no_llseek, 49 .release = drm_release, 50 }; 51 52 static const struct vm_operations_struct vkms_gem_vm_ops = { 53 .fault = vkms_gem_fault, 54 .open = drm_gem_vm_open, 55 .close = drm_gem_vm_close, 56 }; 57 58 static void vkms_release(struct drm_device *dev) 59 { 60 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm); 61 62 platform_device_unregister(vkms->platform); 63 drm_atomic_helper_shutdown(&vkms->drm); 64 drm_mode_config_cleanup(&vkms->drm); 65 drm_dev_fini(&vkms->drm); 66 destroy_workqueue(vkms->output.composer_workq); 67 } 68 69 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 70 { 71 struct drm_device *dev = old_state->dev; 72 struct drm_crtc *crtc; 73 struct drm_crtc_state *old_crtc_state; 74 int i; 75 76 drm_atomic_helper_commit_modeset_disables(dev, old_state); 77 78 drm_atomic_helper_commit_planes(dev, old_state, 0); 79 80 drm_atomic_helper_commit_modeset_enables(dev, old_state); 81 82 drm_atomic_helper_fake_vblank(old_state); 83 84 drm_atomic_helper_commit_hw_done(old_state); 85 86 drm_atomic_helper_wait_for_vblanks(dev, old_state); 87 88 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 89 struct vkms_crtc_state *vkms_state = 90 to_vkms_crtc_state(old_crtc_state); 91 92 flush_work(&vkms_state->composer_work); 93 } 94 95 drm_atomic_helper_cleanup_planes(dev, old_state); 96 } 97 98 static struct drm_driver vkms_driver = { 99 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 100 .release = vkms_release, 101 .fops = &vkms_driver_fops, 102 .dumb_create = vkms_dumb_create, 103 .gem_vm_ops = &vkms_gem_vm_ops, 104 .gem_free_object_unlocked = vkms_gem_free_object, 105 .get_vblank_timestamp = vkms_get_vblank_timestamp, 106 107 .name = DRIVER_NAME, 108 .desc = DRIVER_DESC, 109 .date = DRIVER_DATE, 110 .major = DRIVER_MAJOR, 111 .minor = DRIVER_MINOR, 112 }; 113 114 static const struct drm_mode_config_funcs vkms_mode_funcs = { 115 .fb_create = drm_gem_fb_create, 116 .atomic_check = drm_atomic_helper_check, 117 .atomic_commit = drm_atomic_helper_commit, 118 }; 119 120 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 121 .atomic_commit_tail = vkms_atomic_commit_tail, 122 }; 123 124 static int vkms_modeset_init(struct vkms_device *vkmsdev) 125 { 126 struct drm_device *dev = &vkmsdev->drm; 127 128 drm_mode_config_init(dev); 129 dev->mode_config.funcs = &vkms_mode_funcs; 130 dev->mode_config.min_width = XRES_MIN; 131 dev->mode_config.min_height = YRES_MIN; 132 dev->mode_config.max_width = XRES_MAX; 133 dev->mode_config.max_height = YRES_MAX; 134 dev->mode_config.preferred_depth = 24; 135 dev->mode_config.helper_private = &vkms_mode_config_helpers; 136 137 return vkms_output_init(vkmsdev, 0); 138 } 139 140 static int __init vkms_init(void) 141 { 142 int ret; 143 144 vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL); 145 if (!vkms_device) 146 return -ENOMEM; 147 148 vkms_device->platform = 149 platform_device_register_simple(DRIVER_NAME, -1, NULL, 0); 150 if (IS_ERR(vkms_device->platform)) { 151 ret = PTR_ERR(vkms_device->platform); 152 goto out_free; 153 } 154 155 ret = drm_dev_init(&vkms_device->drm, &vkms_driver, 156 &vkms_device->platform->dev); 157 if (ret) 158 goto out_unregister; 159 160 vkms_device->drm.irq_enabled = true; 161 162 ret = drm_vblank_init(&vkms_device->drm, 1); 163 if (ret) { 164 DRM_ERROR("Failed to vblank\n"); 165 goto out_fini; 166 } 167 168 ret = vkms_modeset_init(vkms_device); 169 if (ret) 170 goto out_fini; 171 172 ret = drm_dev_register(&vkms_device->drm, 0); 173 if (ret) 174 goto out_fini; 175 176 return 0; 177 178 out_fini: 179 drm_dev_fini(&vkms_device->drm); 180 181 out_unregister: 182 platform_device_unregister(vkms_device->platform); 183 184 out_free: 185 kfree(vkms_device); 186 return ret; 187 } 188 189 static void __exit vkms_exit(void) 190 { 191 if (!vkms_device) { 192 DRM_INFO("vkms_device is NULL.\n"); 193 return; 194 } 195 196 drm_dev_unregister(&vkms_device->drm); 197 drm_dev_put(&vkms_device->drm); 198 199 kfree(vkms_device); 200 } 201 202 module_init(vkms_init); 203 module_exit(vkms_exit); 204 205 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 206 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 207 MODULE_DESCRIPTION(DRIVER_DESC); 208 MODULE_LICENSE("GPL"); 209