drm: initial implementation DRM_IOCTL_GET_CAP

Signed-off-by: Andy-Python-Programmer <[email protected]>

Author: Andy-Python-Programmer

src/aero_kernel/src/drivers/drm.rs

@@ -33,6 +33,9 @@ use crate::mem::paging::VirtAddr;
 use uapi::drm::*;
 
 trait DrmDevice: Send + Sync {
+    /// Returns weather the DRM device supports creating dumb buffers.
+    fn dumb_create(&self) -> bool;
+
     /// Returns a tuple containg the driver major, minor and patch level respectively.
     fn driver_version(&self) -> (usize, usize, usize);
     /// Returns a tuple contaning the driver name, desc and date respectively.
@@ -106,6 +109,26 @@ impl INodeInterface for Drm {
                 Ok(0)
             }
 
+            DRM_IOCTL_GET_CAP => {
+                let struc = VirtAddr::new(arg as u64).read_mut::<DrmGetCap>().unwrap();
+
+                // NOTE: The user is responsible for zeroing out the structure.
+                match struc.capability {
+                    DRM_CAP_DUMB_BUFFER => {
+                        if self.device.dumb_create() {
+                            struc.value = 1;
+                        }
+                    }
+
+                    cap => {
+                        log::warn!("drm: unknown capability (`{cap}`)");
+                        return Err(FileSystemError::NotSupported);
+                    }
+                }
+
+                Ok(0)
+            }
+
             _ => {
                 // command[8..16] is the ASCII character supposedly unique to each driver.
                 if command.get_bits(8..16) == DRM_IOCTL_BASE {
@@ -114,7 +137,7 @@ impl INodeInterface for Drm {
                     unimplemented!("drm: function (`{function}`) not supported")
                 }
 
-                log::warn!("drm: unknown ioctl (`{command}`) called");
+                log::warn!("drm: unknown ioctl command (`{command}`)");
                 Err(FileSystemError::NotSupported)
             }
         }
@@ -145,6 +168,10 @@ impl DrmDevice for RawFramebuffer {
     fn driver_info(&self) -> (&'static str, &'static str, &'static str) {
         ("rawfb_gpu", "rawfb gpu", "0")
     }
+
+    fn dumb_create(&self) -> bool {
+        true
+    }
 }
 
 fn init() {

src/uapi/src/drm.rs

@@ -68,5 +68,31 @@ pub struct DrmVersion {
     pub desc: *mut u8, // buffer to hold desc
 }
 
+// Refer to the `libdrm` documentation for more information about the
+// capabilities.
+pub const DRM_CAP_DUMB_BUFFER: u64 = 0x01;
+pub const DRM_CAP_VBLANK_HIGH_CRTC: u64 = 0x02;
+pub const DRM_CAP_DUMB_PREFERRED_DEPTH: u64 = 0x03;
+pub const DRM_CAP_DUMB_PREFER_SHADOW: u64 = 0x04;
+pub const DRM_CAP_PRIME: u64 = 0x05;
+pub const DRM_PRIME_CAP_IMPORT: u64 = 0x01;
+pub const DRM_PRIME_CAP_EXPORT: u64 = 0x02;
+pub const DRM_CAP_TIMESTAMP_MONOTONIC: u64 = 0x06;
+pub const DRM_CAP_ASYNC_PAGE_FLIP: u64 = 0x07;
+pub const DRM_CAP_CURSOR_WIDTH: u64 = 0x08;
+pub const DRM_CAP_CURSOR_HEIGHT: u64 = 0x09;
+pub const DRM_CAP_ADDFB2_MODIFIERS: u64 = 0x10;
+pub const DRM_CAP_PAGE_FLIP_TARGET: u64 = 0x11;
+pub const DRM_CAP_CRTC_IN_VBLANK_EVENT: u64 = 0x12;
+pub const DRM_CAP_SYNCOBJ: u64 = 0x13;
+pub const DRM_CAP_SYNCOBJ_TIMELINE: u64 = 0x14;
+
+#[repr(C)]
+pub struct DrmGetCap {
+    pub capability: u64,
+    pub value: u64,
+}
+
 // DRM IOCTL constants:
 pub const DRM_IOCTL_VERSION: usize = drm_iowr::<DrmVersion>(0x00);
+pub const DRM_IOCTL_GET_CAP: usize = drm_iowr::<DrmGetCap>(0x0c);