drivers/gpu/drm/vkms/vkms_drv.c

   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_probe_helper.h>
  25 #include <drm/drm_vblank.h>
  26
  27 #include "vkms_drv.h"
  28
  29 #define DRIVER_NAME     "vkms"
  30 #define DRIVER_DESC     "Virtual Kernel Mode Setting"
  31 #define DRIVER_DATE     "20180514"
  32 #define DRIVER_MAJOR    1
  33 #define DRIVER_MINOR    0
  34
  35 static struct vkms_device *vkms_device;
  36
  37 bool enable_cursor;
  38 module_param_named(enable_cursor, enable_cursor, bool, 0444);
  39 MODULE_PARM_DESC(enable_cursor, "Enable/Disable cursor support");
  40
  41 static const struct file_operations vkms_driver_fops = {
  42         .owner          = THIS_MODULE,
  43         .open           = drm_open,
  44         .mmap           = drm_gem_mmap,
  45         .unlocked_ioctl = drm_ioctl,
  46         .compat_ioctl   = drm_compat_ioctl,
  47         .poll           = drm_poll,
  48         .read           = drm_read,
  49         .llseek         = no_llseek,
  50         .release        = drm_release,
  51 };
  52
  53 static const struct vm_operations_struct vkms_gem_vm_ops = {
  54         .fault = vkms_gem_fault,
  55         .open = drm_gem_vm_open,
  56         .close = drm_gem_vm_close,
  57 };
  58
  59 static void vkms_release(struct drm_device *dev)
  60 {
  61         struct vkms_device *vkms = container_of(dev, struct vkms_device, drm);
  62
  63         platform_device_unregister(vkms->platform);
  64         drm_atomic_helper_shutdown(&vkms->drm);
  65         drm_mode_config_cleanup(&vkms->drm);
  66         drm_dev_fini(&vkms->drm);
  67         destroy_workqueue(vkms->output.composer_workq);
  68 }
  69
  70 static 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
  99 static 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         .get_vblank_timestamp   = vkms_get_vblank_timestamp,
 107         .prime_fd_to_handle     = drm_gem_prime_fd_to_handle,
 108         .gem_prime_import_sg_table = vkms_prime_import_sg_table,
 109
 110         .name                   = DRIVER_NAME,
 111         .desc                   = DRIVER_DESC,
 112         .date                   = DRIVER_DATE,
 113         .major                  = DRIVER_MAJOR,
 114         .minor                  = DRIVER_MINOR,
 115 };
 116
 117 static const struct drm_mode_config_funcs vkms_mode_funcs = {
 118         .fb_create = drm_gem_fb_create,
 119         .atomic_check = drm_atomic_helper_check,
 120         .atomic_commit = drm_atomic_helper_commit,
 121 };
 122
 123 static const struct drm_mode_config_helper_funcs vkms_mode_config_helpers = {
 124         .atomic_commit_tail = vkms_atomic_commit_tail,
 125 };
 126
 127 static int vkms_modeset_init(struct vkms_device *vkmsdev)
 128 {
 129         struct drm_device *dev = &vkmsdev->drm;
 130
 131         drm_mode_config_init(dev);
 132         dev->mode_config.funcs = &vkms_mode_funcs;
 133         dev->mode_config.min_width = XRES_MIN;
 134         dev->mode_config.min_height = YRES_MIN;
 135         dev->mode_config.max_width = XRES_MAX;
 136         dev->mode_config.max_height = YRES_MAX;
 137         dev->mode_config.preferred_depth = 24;
 138         dev->mode_config.helper_private = &vkms_mode_config_helpers;
 139
 140         return vkms_output_init(vkmsdev, 0);
 141 }
 142
 143 static int __init vkms_init(void)
 144 {
 145         int ret;
 146
 147         vkms_device = kzalloc(sizeof(*vkms_device), GFP_KERNEL);
 148         if (!vkms_device)
 149                 return -ENOMEM;
 150
 151         vkms_device->platform =
 152                 platform_device_register_simple(DRIVER_NAME, -1, NULL, 0);
 153         if (IS_ERR(vkms_device->platform)) {
 154                 ret = PTR_ERR(vkms_device->platform);
 155                 goto out_free;
 156         }
 157
 158         ret = drm_dev_init(&vkms_device->drm, &vkms_driver,
 159                            &vkms_device->platform->dev);
 160         if (ret)
 161                 goto out_unregister;
 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_fini;
 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_fini;
 177         }
 178
 179         ret = vkms_modeset_init(vkms_device);
 180         if (ret)
 181                 goto out_fini;
 182
 183         ret = drm_dev_register(&vkms_device->drm, 0);
 184         if (ret)
 185                 goto out_fini;
 186
 187         return 0;
 188
 189 out_fini:
 190         drm_dev_fini(&vkms_device->drm);
 191
 192 out_unregister:
 193         platform_device_unregister(vkms_device->platform);
 194
 195 out_free:
 196         kfree(vkms_device);
 197         return ret;
 198 }
 199
 200 static 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         kfree(vkms_device);
 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");