Initial support for GEM buffers.

Cargo.lock

@@ -82,7 +82,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d2fabcfbdc87f4758337ca535fb41a6d701b65693ce38287d856d1674551ec9b"
 
 [[package]]
-name = "intel_gpu_uapi"
+name = "intel_gpu"
 version = "0.1.0"
 dependencies = [
  "bindgen",

Cargo.toml

@@ -1,5 +1,5 @@
 [package]
-name = "intel_gpu_uapi"
+name = "intel_gpu"
 version = "0.1.0"
 edition = "2021"
 

src/gpu/i915/mod.rs

@@ -1,14 +1,68 @@
 use std::{ffi::OsString, os::fd::{AsRawFd, OwnedFd}};
+use crate::uapi::i915::DrmGemHandle;
+
 use super::super::uapi;
 use std::path::Path;
 use std::fs::File;
 
+pub use uapi::i915::GemIoctlError;
+
 #[derive(Debug)]
 pub struct DrmDeviceNode {
     pub fd: OwnedFd,
     pub path: Option<OsString>,
 }
 
+#[derive(Debug)]
+pub struct GemHandle<'a> {
+    pub handle: DrmGemHandle,
+    pub node: &'a DrmDeviceNode,
+}
+
+/// An owned GEM handle that will be closed when dropped
+impl GemHandle<'_> {
+    pub fn new(node: &DrmDeviceNode, size: u64) -> Option<GemHandle> {
+        uapi::i915::make_gem(node.fd.as_raw_fd(), size).map(|handle| GemHandle {
+            handle: handle,
+            node: &node,
+        })
+    }
+
+    pub fn from_handle(node: &DrmDeviceNode, handle: DrmGemHandle) -> Result<GemHandle, GemIoctlError> {
+        // Avoid invoking GemHandle::is_valid() here to prevent the drop() method from trying to drop an invalid handle
+        let is_valid = uapi::i915::gem_is_valid(node.fd.as_raw_fd(), handle);
+
+        if is_valid.is_ok() && is_valid.unwrap() {
+            let res = GemHandle {
+                handle: handle,
+                node: &node,
+            };
+            return Ok(res);
+        } else {
+            return Err(is_valid.err().unwrap_or(GemIoctlError::PermissionDenied));
+        }
+    }
+
+    pub fn close(&mut self) -> Result<(), i32> {
+        return uapi::i915::close_gem(self.node.fd.as_raw_fd(), self.handle);
+    }
+
+    pub fn has_tiling(&self) -> Result<bool, uapi::i915::GemIoctlError> {
+        uapi::i915::gem_has_tiling(self.node.fd.as_raw_fd(), self.handle)
+    }
+
+    pub fn is_valid(&self) -> Result<bool, GemIoctlError> {
+        uapi::i915::gem_is_valid(self.node.fd.as_raw_fd(), self.handle)
+    }
+}
+
+impl Drop for GemHandle<'_> {
+    fn drop(&mut self) {
+        // Ignoring the close failing as an invalid Gem handle's drop is a no-op
+        let _ = self.close();
+    }
+}
+
 #[derive(Debug)]
 pub struct Device {
     pub node: DrmDeviceNode,

src/uapi/i915/mod.rs

@@ -29,6 +29,11 @@ pub struct EngineInfo {
     pub capabilities: u64,
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct DrmGemHandle {
+    pub handle: u32,
+}
+
 fn engine_class_from_u16(engine_class: u16) -> EngineClass {
     match engine_class {
         0 => EngineClass::Render,
@@ -83,32 +88,39 @@ impl EngineInfo {
     }
 }
 
+pub unsafe fn do_query<T>(fd: RawFd, query_id: u32) -> Option<*mut T> {
+    let mut query_item = native::drm_i915_query_item {
+        query_id: query_id as u64,
+        length: 0,
+        data_ptr: core::ptr::null_mut::<c_void>() as u64,
+        flags: 0,
+    };
+    let mut query = native::drm_i915_query {
+        items_ptr: (&mut query_item) as *mut native::drm_i915_query_item as u64,
+        num_items: 1,
+        flags: 0,
+    };
+    let res = libc::ioctl(fd.as_raw_fd(), native::DRM_IOCTL_I915_QUERY, &mut query);
+    if res != 0 {
+        return None;
+    }
+    let result_info = libc::malloc(query_item.length as usize)
+        as *mut T;
+    libc::memset(result_info as *mut c_void, 0, query_item.length as usize);
+    query_item.data_ptr = result_info as u64;
+    let res = libc::ioctl(fd.as_raw_fd(), native::DRM_IOCTL_I915_QUERY, &mut query);
+    if res != 0 {
+        return None;
+    }
+    Some(result_info)
+}
+
 pub fn get_engines(fd: RawFd) -> Option<Vec<EngineInfo>> {
     unsafe {
-        let mut query_item = native::drm_i915_query_item {
-            query_id: native::DRM_I915_QUERY_ENGINE_INFO as u64,
-            length: 0,
-            data_ptr: core::ptr::null_mut::<c_void>() as u64,
-            flags: 0,
-        };
-        let mut query = native::drm_i915_query {
-            items_ptr: (&mut query_item) as *mut native::drm_i915_query_item as u64,
-            num_items: 1,
-            flags: 0,
-        };
-        let res = libc::ioctl(fd.as_raw_fd(), native::DRM_IOCTL_I915_QUERY, &mut query);
-        if res != 0 {
-            return None;
-        }
-        let engine_info = libc::malloc(query_item.length as usize)
-            as *mut native::drm_i915_query_engine_info;
-        libc::memset(engine_info as *mut c_void, 0, query_item.length as usize);
-        query_item.data_ptr = engine_info as u64;
-        let res = libc::ioctl(fd.as_raw_fd(), native::DRM_IOCTL_I915_QUERY, &mut query);
-        if res != 0 {
-            return None;
-        }
-        let engine_data = engine_info.as_mut().unwrap();
+        let engine_data = 
+            do_query::<native::drm_i915_query_engine_info>(fd, 
+                native::DRM_I915_QUERY_ENGINE_INFO)?
+            .as_mut().unwrap();
         let engines = engine_data.engines.as_mut_slice(engine_data.num_engines as usize);
         let mut engines_res: Vec<EngineInfo> = Vec::new();
         for i in 0..engine_data.num_engines {
@@ -134,6 +146,94 @@ pub fn get_param(fd: RawFd, param_id: i32) -> Option<i32> {
     }
 }
 
+pub fn get_context_param(fd: RawFd, context_id: u32, param_id: u32) -> Option<u64> {
+    unsafe {
+        let mut param = native::drm_i915_gem_context_param {
+            ctx_id: context_id,
+            param: param_id as u64,
+            value: 0,
+            size: 0,
+        };
+        let res = libc::ioctl(fd, native::DRM_IOCTL_I915_GEM_CONTEXT_GETPARAM, &mut param);
+        if res != 0 {
+            return None;
+        }
+        Some(param.value)
+    }
+}
+
+pub fn make_gem(fd: RawFd, size: u64) -> Option<DrmGemHandle> {
+    unsafe {
+        let mut create = native::drm_i915_gem_create {
+            size: size,
+            handle: 0,
+            pad: 0,
+        };
+        let res = libc::ioctl(fd, native::DRM_IOCTL_I915_GEM_CREATE, &mut create);
+        if res != 0 {
+            return None;
+        }
+        let handle = DrmGemHandle {
+            handle: create.handle,
+        };
+        Some(handle)
+    }
+}
+
+pub fn close_gem(fd: RawFd, handle: DrmGemHandle) -> Result<(), i32> {
+    unsafe {
+        let mut close = native::drm_gem_close {
+            handle: handle.handle,
+            pad: 0,
+        };
+        let res = libc::ioctl(fd, native::DRM_IOCTL_GEM_CLOSE, &mut close);
+        if res != 0 {
+            return Err(res);
+        }
+        Ok(())
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum GemIoctlError {
+    InvalidHandle,
+    PermissionDenied,
+    Unknown(i32),
+}
+
+pub fn gem_has_tiling(fd: RawFd, handle: DrmGemHandle) -> Result<bool, GemIoctlError> {
+    unsafe {
+        let mut tiling = native::drm_i915_gem_set_tiling {
+            handle: handle.handle,
+            tiling_mode: 0,
+            stride: 0,
+            swizzle_mode: 0,
+        };
+        let res = libc::ioctl(fd, native::DRM_IOCTL_I915_GEM_SET_TILING, &mut tiling);
+        match -res {
+            0 => Ok(true),
+            libc::ENOENT => Err(GemIoctlError::InvalidHandle),
+            libc::EPERM => Err(GemIoctlError::PermissionDenied),
+            libc::EINVAL => Ok(false),
+            _ => Err(GemIoctlError::Unknown(res)),
+        }
+    }
+}
+
+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() {
+        return Ok(true);
+    }
+
+    // For some reason the kernel returns -EPERM instead of -ENOENT when the handle is invalid...
+    if res.is_err() && res.unwrap_err() == GemIoctlError::PermissionDenied {
+        return Ok(false);
+    }
+
+    return Err(res.unwrap_err());
+}
+
 pub fn find_node() -> Option<DrmDeviceNode> {
     let inodes = fs::read_dir("/dev/dri").ok()?;
     for inode in inodes {

tests/tests_i915_gpu.rs

@@ -1,4 +1,4 @@
-use intel_gpu_uapi::*;
+use intel_gpu::*;
 use gpu::i915;
 use std::os::fd::{AsRawFd, OwnedFd, RawFd};
 use std::fs::File;
@@ -79,11 +79,37 @@ fn get_vendor_for_fd(fd: RawFd) -> String{
 #[test]
 fn test_i915_gpu_get_param() {
     let device = i915::find_device().expect("Failed to find i915 device");
-    let drm_version = &device.driver;
-    assert_eq!(drm_version.name.to_str().unwrap(), "i915");
-    assert_eq!(drm_version.desc.to_str().unwrap(), "Intel Graphics");
     let chipset_id = device.get_param(native::I915_PARAM_CHIPSET_ID).expect("Failed to get param");
     let chip_id = format!("{:#04x}", chipset_id);
     let dev_id = get_vendor_for_fd(device.node.fd.as_raw_fd());
     assert_eq!(dev_id, chip_id);
+}
+
+#[test]
+fn test_i915_gpu_gem_lifecycle() {
+    let device = i915::find_device().expect("Failed to find i915 device");
+    let gem = i915::GemHandle::new(&device.node, 4096).expect("Failed to create gem handle");
+    let tmp = gem.handle.clone();
+    assert!(gem.is_valid().unwrap());
+    drop(gem);
+    assert!(i915::GemHandle::from_handle(&device.node, tmp).is_err());
+}
+
+#[test]
+fn test_i915_gpu_gem_from_handle() {
+    let device = i915::find_device().expect("Failed to find i915 device");
+    let gem = i915::GemHandle::new(&device.node, 4096).expect("Failed to create gem handle");
+    let tmp = gem.handle.clone();
+    let gem_2 = i915::GemHandle::from_handle(&device.node, tmp).expect("Failed to create gem handle from handle");
+    assert_eq!(gem.handle, gem_2.handle);
+    assert!(gem.is_valid().unwrap());
+    drop(gem);
+    assert!(!gem_2.is_valid().unwrap());
+}
+
+#[test]
+fn test_i915_gpu_gem_has_tiling() {
+    let device = i915::find_device().expect("Failed to find i915 device");
+    let gem = i915::GemHandle::new(&device.node, 4096).expect("Failed to create gem handle");
+    assert!(gem.has_tiling().unwrap());
 }

tests/tests_raw.rs

@@ -1,4 +1,4 @@
-use intel_gpu_uapi::*;
+use intel_gpu::*;
 use std::ffi::c_void;
 use std::ffi::CStr;
 use nix::{self};

tests/tests_uapi.rs

@@ -1,6 +1,6 @@
 #![allow(unused_imports)]
 
-use intel_gpu_uapi::*;
+use intel_gpu::*;
 use uapi::i915;
 use std::fs;
 use std::{fs::File, os::fd::{AsRawFd, RawFd}};
@@ -8,7 +8,9 @@ use std::{fs::File, os::fd::{AsRawFd, RawFd}};
 #[test]
 fn test_i915_uapi_get_version() {
     let node = i915::find_node().expect("Failed to find i915 fd");
-    let _drm_version = uapi::get_drm_version(node.fd.as_raw_fd()).expect("Failed to get drm version");
+    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]
@@ -40,5 +42,39 @@ fn test_i915_uapi_native_engine_info() {
 #[test]
 fn test_i915_find_fd() {
     let fd = i915::find_fd().expect("Failed to find i915 fd");
-    let _drm_version = uapi::get_drm_version(fd.as_raw_fd()).expect("Failed to get drm version");
+    let drm_version = uapi::get_drm_version(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_context_param() {
+    let node = i915::find_node().expect("Failed to find i915 fd");
+    // 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 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());
+    i915::close_gem(node.fd.as_raw_fd(), gem).expect("Failed to close gem");
+    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 gem = i915::make_gem(node.fd.as_raw_fd(), 4096).expect("Failed to make gem");
+    // TODO figure out which devices this holds for
+    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");
 }