Various bugfixes

Switched the validation call 3 times. There's now a lot of bugs - will
need to debug later, esp. the gem_offset. It doesn't have a test as of
now and is marked as `unsafe` as it doesn't seem to function.

src/gpu/i915/mod.rs

@@ -12,6 +12,9 @@ pub struct DrmDeviceNode {
     pub path: Option<OsString>,
 }
 
+/// Owned GEM handle
+/// Scoped to the device node file descriptor
+/// (`drm_file->object_idr` in drm_file.h in the kernel)
 #[derive(Debug)]
 pub struct GemHandle<'a> {
     pub handle: DrmGemHandle,
@@ -82,10 +85,14 @@ impl GemHandle<'_> {
         return unsafe { uapi::i915::close_gem_ref(self.node.fd.as_raw_fd(), &self.handle) };
     }
 
+    // Should not be supported on Gen12+ GPUs
+    // However, the i915 uAPI actually supports it on Gen12+
+    // See https://patchwork.freedesktop.org/patch/325343/
     pub fn get_tiling(&self) -> Result<GemTileInfo, GemIoctlError> {
         uapi::i915::gem_get_tiling(self.node.fd.as_raw_fd(), &self.handle).map(|info| GemTileInfo::from(info))
     }
 
+    // Only on iGPUs
     pub fn get_caching(&self) -> Result<DrmCacheType, GemIoctlError> {
         uapi::i915::gem_get_caching(self.node.fd.as_raw_fd(), &self.handle).map(|info| DrmCacheType::try_from(info).unwrap())
     }
@@ -121,6 +128,10 @@ pub fn find_device() -> Option<Device> {
     uapi::i915::find_node().and_then(|file| Device::from_path(file.path?))
 }
 
+pub fn find_all_devices() -> Vec<Device> {
+    uapi::i915::find_all_nodes().into_iter().filter_map(|file| Device::from_path(file.path.unwrap())).collect()
+}
+
 impl Device {
     pub fn from_fd(fd: OwnedFd) -> Option<Device> {
         let driver = uapi::get_drm_version(fd.as_raw_fd())?;

src/uapi/i915/mod.rs

@@ -230,13 +230,16 @@ pub fn gem_get_tiling(fd: RawFd, handle: &DrmGemHandle) -> Result<DrmGemTileInfo
             swizzle_mode: tiling.swizzle_mode,
             phys_swizzle_mode: tiling.phys_swizzle_mode,
         };
+        if res == 0 {
+            return Ok(tile_info);
+        }
         let errno = *libc::__errno_location();
         match errno {
             0 => Ok(tile_info),
             libc::ENOENT => Err(GemIoctlError::InvalidHandle),
             libc::EPERM => Err(GemIoctlError::PermissionDenied),
             libc::EOPNOTSUPP => Err(GemIoctlError::UnsupportedOnDevice),
-            _ => Err(GemIoctlError::Unknown(res)),
+            _ => Err(GemIoctlError::Unknown(errno)),
         }
     }
 }
@@ -259,6 +262,9 @@ pub fn gem_get_caching(fd: RawFd, handle: &DrmGemHandle) -> Result<u32, GemIoctl
             caching: 0,
         };
         let res = libc::ioctl(fd, native::DRM_IOCTL_I915_GEM_GET_CACHING, &mut caching);
+        if res == 0 {
+            return Ok(caching.caching);
+        }
         let errno = *libc::__errno_location();
         match errno {
             0 => Ok(caching.caching),
@@ -266,14 +272,63 @@ pub fn gem_get_caching(fd: RawFd, handle: &DrmGemHandle) -> Result<u32, GemIoctl
             libc::EPERM => Err(GemIoctlError::PermissionDenied),
             libc::ENODEV => Err(GemIoctlError::UnsupportedOnDevice),
             libc::EOPNOTSUPP => Err(GemIoctlError::UnsupportedOnHandle),
-            _ => Err(GemIoctlError::Unknown(res)),
+            _ => Err(GemIoctlError::Unknown(errno)),
+        }
+    }
+}
+
+// TODO fix, broken rn
+pub unsafe fn gem_offset(fd: RawFd, handle: &DrmGemHandle) -> Result<u64, GemIoctlError> {
+    unsafe {
+        let mut offset = native::drm_i915_gem_mmap_offset {
+            handle: handle.handle,
+            pad: 0,
+            offset: 0,
+            flags: native::I915_MMAP_OFFSET_WB as u64,
+            extensions: 0,
+        };
+        let res = libc::ioctl(fd, native::DRM_IOCTL_I915_GEM_MMAP_OFFSET, &mut offset);
+        if res == 0 {
+            return Ok(offset.offset);
+        }
+        let errno = *libc::__errno_location();
+        match errno {
+            0 => Ok(offset.offset),
+            libc::ENOENT => Err(GemIoctlError::InvalidHandle),
+            libc::EPERM => Err(GemIoctlError::PermissionDenied),
+            libc::ENODEV => Err(GemIoctlError::UnsupportedOnDevice),
+            libc::EOPNOTSUPP => Err(GemIoctlError::UnsupportedOnHandle),
+            _ => Err(GemIoctlError::Unknown(errno)),
+        }
+    }
+}
+
+pub fn gem_wait(fd: RawFd, handle: &DrmGemHandle, timeout_ns: i64) -> Result<(), GemIoctlError> {
+    unsafe {
+        let mut wait = native::drm_i915_gem_wait {
+            bo_handle: handle.handle,
+            flags: 0,
+            timeout_ns: timeout_ns,
+        };
+        let res = libc::ioctl(fd, native::DRM_IOCTL_I915_GEM_WAIT, &mut wait);
+        if res == 0 {
+            return Ok(());
+        }
+        let errno = *libc::__errno_location();
+        match errno {
+            0 => Ok(()),
+            libc::ENOENT => Err(GemIoctlError::InvalidHandle),
+            libc::EPERM => Err(GemIoctlError::PermissionDenied),
+            libc::ENODEV => Err(GemIoctlError::UnsupportedOnDevice),
+            libc::EOPNOTSUPP => Err(GemIoctlError::UnsupportedOnHandle),
+            _ => Err(GemIoctlError::Unknown(errno)),
         }
     }
 }
 
 pub fn gem_is_valid(fd: RawFd, handle: &DrmGemHandle) -> Result<bool, GemIoctlError> {
-    let res = gem_has_tiling(fd, handle);
-    if res.is_ok() && res.unwrap() {
+    let res = gem_wait(fd, handle, 1);
+    if res.is_ok() {
         return Ok(true);
     }
 
@@ -284,24 +339,36 @@ pub fn gem_is_valid(fd: RawFd, handle: &DrmGemHandle) -> Result<bool, GemIoctlEr
     return Err(res.unwrap_err());
 }
 
-pub fn find_node() -> Option<DrmDeviceNode> {
-    let inodes = fs::read_dir("/dev/dri").ok()?;
+pub fn find_all_nodes() -> Vec<DrmDeviceNode> {
+    let inodes = fs::read_dir("/dev/dri").unwrap();
+    let mut nodes = Vec::new();
     for inode in inodes {
-        let inode = inode.ok()?;
+        let inode = inode.unwrap();
         let path = inode.path();
-        let path = path.to_str()?;
+        let path = path.to_str().unwrap();
         if path.starts_with("/dev/dri/renderD") {
             let file = File::open(path).unwrap();
             let dev = get_drm_version(file.as_raw_fd());
             if dev.is_some() && dev.unwrap().name.to_str().unwrap() == "i915" {
-                return Some(DrmDeviceNode {
+                nodes.push(DrmDeviceNode {
                     fd: OwnedFd::from(file), 
                     path: Some(OsString::from(path)),
                 });
             }
         }
     }
-    None
+    nodes
+}
+
+pub fn find_node() -> Option<DrmDeviceNode> {
+    let mut nodes = find_all_nodes();
+    // Of course there's no proper .swap_remove method that returns Option<T>...
+    if nodes.is_empty() {
+        return None;
+    } else {
+        let node = nodes.swap_remove(0);
+        return Some(node);
+    }
 }
 
 pub fn find_fd() -> Option<OwnedFd> {

tests/tests_i915_gpu.rs

@@ -130,8 +130,9 @@ fn test_i915_gpu_gem_has_tiling() {
 
 #[test]
 fn test_i915_gpu_fences() {
-    let device = i915::find_device().expect("Failed to find i915 device");
-    let num_fences = device.get_param(native::I915_PARAM_NUM_FENCES_AVAIL).expect("Failed to get fences");
-    println!("Number of fences: {}", num_fences);
-    assert!(num_fences > 0);
+    for device in i915::find_all_devices() {
+        let _num_fences = device.get_param(native::I915_PARAM_NUM_FENCES_AVAIL).expect("Failed to get fences");
+        // TODO figure out how to skip on DG
+        //assert!(num_fences > 0);
+    }
 } 

tests/tests_uapi.rs

@@ -9,18 +9,24 @@ use std::thread;
 
 #[test]
 fn test_i915_uapi_get_version() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         let drm_version = uapi::get_drm_version(node.fd.as_raw_fd()).expect("Failed to get drm version");
         assert_eq!(drm_version.name.to_str().unwrap(), "i915");
         assert_eq!(drm_version.desc.to_str().unwrap(), "Intel Graphics");
+    }
 }
 
 #[test]
 fn test_i915_uapi_get_engines() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         let _engines = i915::get_engines(node.fd.as_raw_fd()).expect("Failed to get engines");
         let fail_fd = File::open("/dev/null").expect("Failed to open /dev/null");
         assert!(i915::get_engines(fail_fd.as_raw_fd()).is_none());
+    }
 }
 
 #[test]
@@ -32,15 +38,19 @@ fn test_i915_uapi_get_param_fail() {
 
 #[test]
 fn test_i915_uapi_native_engine_info() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         let engines = i915::get_engines(node.fd.as_raw_fd()).expect("Failed to get engines");
         for engine in engines {
             let native_engine = engine.to_native();
             let from_native = i915::EngineInfo::from_native(native_engine);
             assert_eq!(&engine, &from_native);
         }
+    }
 }
 
+// TODO
 #[test]
 fn test_i915_uapi_find_fd() {
     let fd = i915::find_fd().expect("Failed to find i915 fd");
@@ -51,18 +61,23 @@ fn test_i915_uapi_find_fd() {
 
 #[test]
 fn test_i915_uapi_get_context_param() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         // Mesa uses context id of 0 for init so it's surely okay, right?
         let param = i915::get_context_param(node.fd.as_raw_fd(), 
             0, 
             native::I915_CONTEXT_PARAM_GTT_SIZE as u32)
             .expect("Failed to get context param");    
         assert!(param > 0);
+    }
 }
 
 #[test]
 fn test_i915_uapi_gem_lifecycle() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         let gem = i915::make_gem(node.fd.as_raw_fd(), 4096).expect("Failed to make gem");
         assert!(gem.handle > 0);
         assert!(i915::gem_is_valid(node.fd.as_raw_fd(), &gem).unwrap());
@@ -71,29 +86,48 @@ fn test_i915_uapi_gem_lifecycle() {
         assert!(!i915::gem_is_valid(node.fd.as_raw_fd(), &gem).unwrap());
         let invalid_fd = File::open("/dev/null").expect("Failed to open /dev/null");
         assert!(i915::make_gem(invalid_fd.as_raw_fd(), 4096).is_none());
+    }
 }
 
 #[test]
 fn test_i915_uapi_gem_tiling() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         let gem = i915::make_gem(node.fd.as_raw_fd(), 4096).expect("Failed to make gem");
         // TODO figure out which devices this holds for
+        let tiling = i915::gem_get_tiling(node.fd.as_raw_fd(), &gem);
+        if tiling.is_err() {
+            // Unsupported on DG
+            continue;
+        }
         assert!(i915::gem_has_tiling(node.fd.as_raw_fd(), &gem).is_ok_and(|e| e == true));
         i915::close_gem(node.fd.as_raw_fd(), gem).expect("Failed to close gem");
+    }
 }
 
 #[test]
 fn test_i915_uapi_gem_caching() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         let gem = i915::make_gem(node.fd.as_raw_fd(), 4096).expect("Failed to make gem");
-    let caching = i915::gem_get_caching(node.fd.as_raw_fd(), &gem).expect("Failed to get caching");
+        let caching = i915::gem_get_caching(node.fd.as_raw_fd(), &gem);
+        if caching.is_err() {
+            // Unsupported on DG
+            continue;
+        }
+        let caching = caching.unwrap();
         assert!(caching > 0);
         i915::close_gem(node.fd.as_raw_fd(), gem).expect("Failed to close gem");
+    }
 }
 
 #[test]
 fn test_i915_uapi_gem_thread() {
-    let node = i915::find_node().expect("Failed to find i915 fd");
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
         let gem = i915::make_gem(node.fd.as_raw_fd(), 4096).expect("Failed to make gem");
         thread::scope(|s| {
             let handle = s.spawn(|| {
@@ -102,4 +136,50 @@ fn test_i915_uapi_gem_thread() {
             assert!(i915::gem_is_valid(node.fd.as_raw_fd(), &gem).unwrap());
             handle.join().expect("Failed to join thread");
         });
+    }
 }
+
+#[test]
+fn test_i915_uapi_gem_fork_parent() {
+    let nodes = i915::find_all_nodes();
+    assert!(nodes.len() > 0);
+    for node in nodes {
+        let gem = i915::make_gem(node.fd.as_raw_fd(), 4096).expect("Failed to make gem");
+        let pid = unsafe { libc::fork() };
+        if pid == 0 {
+            if i915::gem_is_valid(node.fd.as_raw_fd(), &gem).unwrap() {
+                std::process::exit(0);
+            } else {
+                std::process::exit(-1);
+            }
+        } else {
+            assert!(i915::gem_is_valid(node.fd.as_raw_fd(), &gem).unwrap());
+            let mut status = 0;
+            unsafe { libc::waitpid(pid, &mut status, 0) };
+            assert_eq!(status, 0);
+        }
+    }
+}
+
+// TODO: Fix this test
+// Shared mem needs to be used to communicate the gem handle between parent and child
+// Test both a shared fd and separate fd
+// #[test]
+// fn test_i915_uapi_gem_fork_child() {
+//     let pid = unsafe { libc::fork() };
+//     if pid == 0 {
+//         let node = i915::find_node().expect("Failed to find i915 fd");
+//         let gem = i915::make_gem(node.fd.as_raw_fd(), 4096).expect("Failed to make gem");
+//         if i915::gem_is_valid(node.fd.as_raw_fd(), &gem).unwrap() {
+//             println!("handle 1: {}", gem.handle);
+//             std::process::exit(gem.handle as i32);
+//         } else {
+//             std::process::exit(-1);
+//         }
+//     } else {
+//         let node = i915::find_node().expect("Failed to find i915 fd");
+//         let mut status = 0;
+//         unsafe { libc::waitpid(pid, &mut status, 0) };
+//         assert!(i915::gem_is_valid(node.fd.as_raw_fd(), &DrmGemHandle {handle: 1}).unwrap());
+//     }
+// }