drm/i915: wait render timeout ioctl
This helps implement GL_ARB_sync but stops short of allowing full blown
sync objects. Finally we can use the new timed seqno waiting function
to allow userspace to wait on a buffer object with a timeout. This
implements that interface.
The IOCTL will take as input a buffer object handle, and a timeout in
nanoseconds (flags is currently optional but will likely be used for
permutations of flush operations). Users may specify 0 nanoseconds to
instantly check.
The wait ioctl with a timeout of 0 reimplements the busy ioctl. With any
non-zero timeout parameter the wait ioctl will wait for the given number
of nanoseconds on an object becoming unbusy. Since the wait itself does
so holding struct_mutex the object may become re-busied before this
completes. A similar but shorter race condition exists in the busy
ioctl.
v2: ETIME/ERESTARTSYS instead of changing to EBUSY, and EGAIN (Chris)
Flush the object from the gpu write domain (Chris + Daniel)
Fix leaked refcount in good case (Chris)
Naturally align ioctl struct (Chris)
v3: Drop lock after getting seqno to avoid ugly dance (Chris)
v4: check for 0 timeout after olr check to allow polling (Chris)
v5: Updated the comment. (Chris)
v6: Return -ETIME instead of -EBUSY when timeout_ns is 0 (Daniel)
Fix the commit message comment to be less ugly (Ben)
Add a warning to check the return timespec (Ben)
v7: Use DRM_AUTH for the ioctl. (Eugeni)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 11c7a6a..8ac10e8 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1229,6 +1229,8 @@
struct drm_file *file_priv);
int i915_gem_get_aperture_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
+int i915_gem_wait_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_priv);
void i915_gem_load(struct drm_device *dev);
int i915_gem_init_object(struct drm_gem_object *obj);
int __must_check i915_gem_flush_ring(struct intel_ring_buffer *ring,