drm: initial implementation DRM_IOCTL_MODE_ADDFB

Signed-off-by: Andy-Python-Programmer <andypythonappdeveloper@gmail.com>

Author: Andy-Python-Programmer

src/aero_kernel/src/drivers/drm/mod.rs

@@ -69,7 +69,9 @@ trait ModeObject: Send + Sync + Downcastable {
 trait DrmDevice: Send + Sync {
     /// Returns weather the DRM device supports creating dumb buffers.
     fn can_dumb_create(&self) -> bool;
+
     fn dumb_create(&self, width: u32, height: u32, bpp: u32) -> BufferObject;
+    fn framebuffer_create(&self, buffer_object: &BufferObject, width: u32, height: u32, pitch: u32);
 
     /// Returns tuple containing the minumum dimensions (`xmin`, `ymin`).
     fn min_dim(&self) -> (usize, usize);
@@ -82,6 +84,7 @@ trait DrmDevice: Send + Sync {
     fn driver_info(&self) -> (&'static str, &'static str, &'static str);
 }
 
+#[derive(Clone)]
 struct BufferObject {
     width: u32,
     height: u32,
@@ -251,6 +254,15 @@ struct Framebuffer {
     object_id: u32,
 }
 
+impl Framebuffer {
+    pub fn new(object_id: u32) -> Arc<Self> {
+        Arc::new_cyclic(|sref| Self {
+            sref: sref.clone(),
+            object_id,
+        })
+    }
+}
+
 impl ModeObject for Framebuffer {
     fn id(&self) -> u32 {
         self.object_id
@@ -360,6 +372,12 @@ impl Drm {
         self.install_object(encoder)
     }
 
+    /// Installs and initializes the framebuffer identifier.
+    pub fn install_framebuffer(&self, fb: Arc<Framebuffer>) {
+        self.framebuffers.lock().push(fb.clone());
+        self.install_object(fb)
+    }
+
     pub fn allocate_object_id(&self) -> u32 {
         self.id_alloc.alloc() as _
     }
@@ -369,7 +387,11 @@ impl Drm {
     }
 
     fn find_object(&self, id: u32) -> Option<Arc<dyn ModeObject>> {
-        self.mode_objs.lock().get(&id).map(|obj| obj.clone())
+        self.mode_objs.lock().get(&id).cloned()
+    }
+
+    fn find_handle(&self, handle: u32) -> Option<BufferObject> {
+        self.buffers.lock().get(&handle).cloned()
     }
 
     fn create_handle(&self, buffer: BufferObject) -> u32 {
@@ -556,6 +578,22 @@ impl INodeInterface for Drm {
                 Ok(0)
             }
 
+            DRM_IOCTL_MODE_ADDFB => {
+                let struc = VirtAddr::new(arg as u64)
+                    .read_mut::<DrmModeFbCmd>()
+                    .unwrap();
+
+                let handle = self.find_handle(struc.handle).unwrap();
+                self.device
+                    .framebuffer_create(&handle, struc.width, struc.height, struc.pitch);
+
+                let fb = Framebuffer::new(self.allocate_object_id());
+                self.install_framebuffer(fb.clone());
+
+                struc.fb_id = fb.id();
+                Ok(0)
+            }
+
             _ => {
                 // command[8..16] is the ASCII character supposedly unique to each driver.
                 if command.get_bits(8..16) == DRM_IOCTL_BASE {

src/aero_kernel/src/drivers/drm/rawfb.rs

@@ -39,6 +39,17 @@ impl DrmDevice for RawFramebuffer {
         BufferObject::new(width, height, size as usize)
     }
 
+    fn framebuffer_create(
+        &self,
+        buffer_object: &BufferObject,
+        _width: u32,
+        height: u32,
+        pitch: u32,
+    ) {
+        assert!(pitch % 4 == 0);
+        assert!(buffer_object.size >= pitch as usize * height as usize);
+    }
+
     fn driver_version(&self) -> (usize, usize, usize) {
         (0, 0, 1)
     }
@@ -62,7 +73,6 @@ fn init() {
     let info = rendy::get_rendy_info();
 
     let rfb = Drm::new(Arc::new(RawFramebuffer {}));
-
     let crtc = Crtc::new(&rfb, rfb.allocate_object_id());
 
     let encoder = Encoder::new(

src/uapi/src/drm.rs

@@ -198,6 +198,17 @@ pub struct DrmModeGetConnector {
     pub pad: u32, // padding; must be zero
 }
 
+#[repr(C)]
+pub struct DrmModeFbCmd {
+    pub fb_id: u32,
+    pub width: u32,
+    pub height: u32,
+    pub pitch: u32,
+    pub bpp: u32,
+    pub depth: u32,
+    pub handle: u32, // driver specific handle
+}
+
 #[repr(C)]
 pub struct DrmModeCreateDumb {
     pub height: u32,
@@ -218,5 +229,6 @@ pub const DRM_IOCTL_GET_CAP: usize = drm_iowr::<DrmGetCap>(0x0c);
 pub const DRM_IOCTL_MODE_GETRESOURCES: usize = drm_iowr::<DrmModeCardRes>(0xa0);
 pub const DRM_IOCTL_GET_ENCODER: usize = drm_iowr::<DrmModeGetEncoder>(0xa6);
 pub const DRM_IOCTL_GET_CONNECTOR: usize = drm_iowr::<DrmModeGetConnector>(0xa7);
+pub const DRM_IOCTL_MODE_ADDFB: usize = drm_iowr::<DrmModeFbCmd>(0xae);
 
 pub const DRM_IOCTL_MODE_CREATE_DUMB: usize = drm_iowr::<DrmModeCreateDumb>(0xb2);