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>
This commit is contained in:
Ben Widawsky
2012-05-25 14:15:46 +02:00
committed by Daniel Vetter
parent f3fd37683c
commit 23ba4fd0a4
4 changed files with 99 additions and 0 deletions
+10
View File
@@ -200,6 +200,7 @@ typedef struct _drm_i915_sarea {
#define DRM_I915_GEM_EXECBUFFER2 0x29
#define DRM_I915_GET_SPRITE_COLORKEY 0x2a
#define DRM_I915_SET_SPRITE_COLORKEY 0x2b
#define DRM_I915_GEM_WAIT 0x2c
#define DRM_IOCTL_I915_INIT DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
#define DRM_IOCTL_I915_FLUSH DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -243,6 +244,7 @@ typedef struct _drm_i915_sarea {
#define DRM_IOCTL_I915_OVERLAY_ATTRS DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_OVERLAY_ATTRS, struct drm_intel_overlay_attrs)
#define DRM_IOCTL_I915_SET_SPRITE_COLORKEY DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_SET_SPRITE_COLORKEY, struct drm_intel_sprite_colorkey)
#define DRM_IOCTL_I915_GET_SPRITE_COLORKEY DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_SET_SPRITE_COLORKEY, struct drm_intel_sprite_colorkey)
#define DRM_IOCTL_I915_GEM_WAIT DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_GEM_WAIT, struct drm_i915_gem_wait)
/* Allow drivers to submit batchbuffers directly to hardware, relying
* on the security mechanisms provided by hardware.
@@ -886,4 +888,12 @@ struct drm_intel_sprite_colorkey {
__u32 flags;
};
struct drm_i915_gem_wait {
/** Handle of BO we shall wait on */
__u32 bo_handle;
__u32 flags;
/** Number of nanoseconds to wait, Returns time remaining. */
__u64 timeout_ns;
};
#endif /* _I915_DRM_H_ */