drm/i915: Derive GEM requests from dma-fence
dma-buf provides a generic fence class for interoperation between
drivers. Internally we use the request structure as a fence, and so with
only a little bit of interfacing we can rebase those requests on top of
dma-buf fences. This will allow us, in the future, to pass those fences
back to userspace or between drivers.
v2: The fence_context needs to be globally unique, not just unique to
this device.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1469002875-2335-4-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_gem_request.h b/drivers/gpu/drm/i915/i915_gem_request.h
index ea700be..6f2c820 100644
--- a/drivers/gpu/drm/i915/i915_gem_request.h
+++ b/drivers/gpu/drm/i915/i915_gem_request.h
@@ -25,6 +25,10 @@
#ifndef I915_GEM_REQUEST_H
#define I915_GEM_REQUEST_H
+#include <linux/fence.h>
+
+#include "i915_gem.h"
+
/**
* Request queue structure.
*
@@ -36,11 +40,11 @@
* emission time to be associated with the request for tracking how far ahead
* of the GPU the submission is.
*
- * The requests are reference counted, so upon creation they should have an
- * initial reference taken using kref_init
+ * The requests are reference counted.
*/
struct drm_i915_gem_request {
- struct kref ref;
+ struct fence fence;
+ spinlock_t lock;
/** On Which ring this request was generated */
struct drm_i915_private *i915;
@@ -66,12 +70,6 @@
*/
u32 previous_seqno;
- /** GEM sequence number associated with this request,
- * when the HWS breadcrumb is equal or greater than this the GPU
- * has finished processing this request.
- */
- u32 seqno;
-
/** Position in the ringbuffer of the start of the request */
u32 head;
@@ -140,10 +138,16 @@
unsigned int ctx_hw_id;
};
+extern const struct fence_ops i915_fence_ops;
+
+static inline bool fence_is_i915(struct fence *fence)
+{
+ return fence->ops == &i915_fence_ops;
+}
+
struct drm_i915_gem_request * __must_check
i915_gem_request_alloc(struct intel_engine_cs *engine,
struct i915_gem_context *ctx);
-void i915_gem_request_free(struct kref *req_ref);
int i915_gem_request_add_to_client(struct drm_i915_gem_request *req,
struct drm_file *file);
void i915_gem_request_retire_upto(struct drm_i915_gem_request *req);
@@ -151,7 +155,7 @@
static inline u32
i915_gem_request_get_seqno(struct drm_i915_gem_request *req)
{
- return req ? req->seqno : 0;
+ return req ? req->fence.seqno : 0;
}
static inline struct intel_engine_cs *
@@ -161,17 +165,24 @@
}
static inline struct drm_i915_gem_request *
+to_request(struct fence *fence)
+{
+ /* We assume that NULL fence/request are interoperable */
+ BUILD_BUG_ON(offsetof(struct drm_i915_gem_request, fence) != 0);
+ GEM_BUG_ON(fence && !fence_is_i915(fence));
+ return container_of(fence, struct drm_i915_gem_request, fence);
+}
+
+static inline struct drm_i915_gem_request *
i915_gem_request_reference(struct drm_i915_gem_request *req)
{
- if (req)
- kref_get(&req->ref);
- return req;
+ return to_request(fence_get(&req->fence));
}
static inline void
i915_gem_request_unreference(struct drm_i915_gem_request *req)
{
- kref_put(&req->ref, i915_gem_request_free);
+ fence_put(&req->fence);
}
static inline void i915_gem_request_assign(struct drm_i915_gem_request **pdst,
@@ -223,7 +234,7 @@
i915_gem_request_completed(const struct drm_i915_gem_request *req)
{
return i915_seqno_passed(intel_engine_get_seqno(req->engine),
- req->seqno);
+ req->fence.seqno);
}
bool __i915_spin_request(const struct drm_i915_gem_request *request,