Add Device::syncobj_eventfd

drm-ffi/src/ioctl.rs

@@ -278,4 +278,6 @@ pub(crate) mod syncobj {
         0xCD,
         drm_syncobj_timeline_array
     );
+    /// Register an eventfd to be signalled by a syncobj.
+    ioctl_readwrite!(eventfd, DRM_IOCTL_BASE, 0xCF, drm_syncobj_eventfd);
 }

drm-ffi/src/syncobj.rs

@@ -264,3 +264,31 @@ pub fn timeline_signal(
 
     Ok(args)
 }
+
+/// Register an eventfd to be signalled by a syncobj.
+pub fn eventfd(
+    fd: BorrowedFd<'_>,
+    handle: u32,
+    point: u64,
+    eventfd: BorrowedFd<'_>,
+    wait_available: bool,
+) -> io::Result<drm_syncobj_eventfd> {
+    let flags = if wait_available {
+        DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE
+    } else {
+        0
+    };
+    let mut args = drm_syncobj_eventfd {
+        handle,
+        point,
+        flags,
+        fd: eventfd.as_raw_fd(),
+        pad: 0,
+    };
+
+    unsafe {
+        ioctl::syncobj::eventfd(fd, &mut args)?;
+    }
+
+    Ok(args)
+}

src/control/mod.rs

@@ -51,7 +51,7 @@
 use super::util::*;
 
 use std::collections::HashMap;
 use std::convert::TryFrom;
 use std::error;
 use std::fmt;
 use std::io;
@@ -954,6 +954,18 @@
         Ok(())
     }
 
+    /// Register an eventfd to be signalled by a syncobj.
+    fn syncobj_eventfd(
+        &self,
+        handle: syncobj::Handle,
+        point: u64,
+        eventfd: BorrowedFd<'_>,
+        wait_available: bool,
+    ) -> io::Result<()> {
+        ffi::syncobj::eventfd(self.as_fd(), handle.into(), point, eventfd, wait_available)?;
+        Ok(())
+    }
+
     /// Create a drm lease
     fn create_lease(
         &self,