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 36 static struct vkms_device *vkms_device; 37 38 bool enable_cursor = true; 39 module_param_named(enable_cursor, enable_cursor, bool, 0444); 40 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support"); 41 42 static 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 54 static 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 60 static void vkms_release(struct drm_device *dev) 61 { 62 struct vkms_device *vkms = container_of(dev, struct vkms_device, drm); 63 64 destroy_workqueue(vkms->output.composer_workq); 65 } 66 67 static void vkms_atomic_commit_tail(struct drm_atomic_state *old_state) 68 { 69 struct drm_device *dev = old_state->dev; 70 struct drm_crtc *crtc; 71 struct drm_crtc_state *old_crtc_state; 72 int i; 73 74 drm_atomic_helper_commit_modeset_disables(dev, old_state); 75 76 drm_atomic_helper_commit_planes(dev, old_state, 0); 77 78 drm_atomic_helper_commit_modeset_enables(dev, old_state); 79 80 drm_atomic_helper_fake_vblank(old_state); 81 82 drm_atomic_helper_commit_hw_done(old_state); 83 84 drm_atomic_helper_wait_for_flip_done(dev, old_state); 85 86 for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) { 87 struct vkms_crtc_state *vkms_state = 88 to_vkms_crtc_state(old_crtc_state); 89 90 flush_work(&vkms_state->composer_work); 91 } 92 93 drm_atomic_helper_cleanup_planes(dev, old_state); 94 } 95 96 static struct drm_driver vkms_driver = { 97 .driver_features = DRIVER_MODESET | DRIVER_ATOMIC | DRIVER_GEM, 98 .release = vkms_release, 99 .fops = &vkms_driver_fops, 100 .dumb_create = vkms_dumb_create, 101 .gem_vm_ops = &vkms_gem_vm_ops, 102 .gem_free_object_unlocked = vkms_gem_free_object, 103 .prime_fd_to_handle = drm_gem_prime_fd_to_handle, 104 .gem_prime_import_sg_table = vkms_prime_import_sg_table, 105 106 .name = DRIVER_NAME, 107 .desc = DRIVER_DESC, 108 .date = DRIVER_DATE, 109 .major = DRIVER_MAJOR, 110 .minor = DRIVER_MINOR, 111 }; 112 113 static const struct drm_mode_config_funcs vkms_mode_funcs = { 114 .fb_create = drm_gem_fb_create, 115 .atomic_check = drm_atomic_helper_check, 116 .atomic_commit = drm_atomic_helper_commit, 117 }; 118 119 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = { 120 .atomic_commit_tail = vkms_atomic_commit_tail, 121 }; 122 123 static int vkms_modeset_init(struct vkms_device *vkmsdev) 124 { 125 struct drm_device *dev = &vkmsdev->drm; 126 127 drm_mode_config_init(dev); 128 dev->mode_config.funcs = &vkms_mode_funcs; 129 dev->mode_config.min_width = XRES_MIN; 130 dev->mode_config.min_height = YRES_MIN; 131 dev->mode_config.max_width = XRES_MAX; 132 dev->mode_config.max_height = YRES_MAX; 133 dev->mode_config.cursor_width = 512; 134 dev->mode_config.cursor_height = 512; 135 dev->mode_config.preferred_depth = 24; 136 dev->mode_config.helper_private = &vkms_mode_config_helpers; 137 138 return vkms_output_init(vkmsdev, 0); 139 } 140 141 static int __init vkms_init(void) 142 { 143 int ret; 144 struct platform_device *pdev; 145 146 pdev = platform_device_register_simple(DRIVER_NAME, -1, NULL, 0); 147 if (IS_ERR(pdev)) 148 return PTR_ERR(pdev); 149 150 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) { 151 ret = -ENOMEM; 152 goto out_unregister; 153 } 154 155 vkms_device = devm_drm_dev_alloc(&pdev->dev, &vkms_driver, 156 struct vkms_device, drm); 157 if (IS_ERR(vkms_device)) { 158 ret = PTR_ERR(vkms_device); 159 goto out_devres; 160 } 161 vkms_device->platform = pdev; 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_devres; 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_devres; 177 } 178 179 ret = vkms_modeset_init(vkms_device); 180 if (ret) 181 goto out_devres; 182 183 ret = drm_dev_register(&vkms_device->drm, 0); 184 if (ret) 185 goto out_devres; 186 187 return 0; 188 189 out_devres: 190 devres_release_group(&pdev->dev, NULL); 191 out_unregister: 192 platform_device_unregister(pdev); 193 return ret; 194 } 195 196 static void __exit vkms_exit(void) 197 { 198 struct platform_device *pdev; 199 200 if (!vkms_device) { 201 DRM_INFO("vkms_device is NULL.\n"); 202 return; 203 } 204 205 pdev = vkms_device->platform; 206 207 drm_dev_unregister(&vkms_device->drm); 208 drm_atomic_helper_shutdown(&vkms_device->drm); 209 devres_release_group(&pdev->dev, NULL); 210 platform_device_unregister(pdev); 211 } 212 213 module_init(vkms_init); 214 module_exit(vkms_exit); 215 216 MODULE_AUTHOR("Haneen Mohammed <hamohammed.sa@gmail.com>"); 217 MODULE_AUTHOR("Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>"); 218 MODULE_DESCRIPTION(DRIVER_DESC); 219 MODULE_LICENSE("GPL"); 220