Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 727 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
new file mode 100644
index 000000000..47041ec68
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -0,0 +1,727 @@
+/*
+ * Copyright © 2008-2018 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef I915_REQUEST_H
+#define I915_REQUEST_H
+
+#include <linux/dma-fence.h>
+#include <linux/hrtimer.h>
+#include <linux/irq_work.h>
+#include <linux/llist.h>
+#include <linux/lockdep.h>
+
+#include "gem/i915_gem_context_types.h"
+#include "gt/intel_context_types.h"
+#include "gt/intel_engine_types.h"
+#include "gt/intel_timeline_types.h"
+
+#include "i915_gem.h"
+#include "i915_scheduler.h"
+#include "i915_selftest.h"
+#include "i915_sw_fence.h"
+#include "i915_vma_resource.h"
+
+#include <uapi/drm/i915_drm.h>
+
+struct drm_file;
+struct drm_i915_gem_object;
+struct drm_printer;
+struct i915_deps;
+struct i915_request;
+
+#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
+struct i915_capture_list {
+	struct i915_vma_resource *vma_res;
+	struct i915_capture_list *next;
+};
+
+void i915_request_free_capture_list(struct i915_capture_list *capture);
+#else
+#define i915_request_free_capture_list(_a) do {} while (0)
+#endif
+
+#define RQ_TRACE(rq, fmt, ...) do {					\
+	const struct i915_request *rq__ = (rq);				\
+	ENGINE_TRACE(rq__->engine, "fence %llx:%lld, current %d " fmt,	\
+		     rq__->fence.context, rq__->fence.seqno,		\
+		     hwsp_seqno(rq__), ##__VA_ARGS__);			\
+} while (0)
+
+enum {
+	/*
+	 * I915_FENCE_FLAG_ACTIVE - this request is currently submitted to HW.
+	 *
+	 * Set by __i915_request_submit() on handing over to HW, and cleared
+	 * by __i915_request_unsubmit() if we preempt this request.
+	 *
+	 * Finally cleared for consistency on retiring the request, when
+	 * we know the HW is no longer running this request.
+	 *
+	 * See i915_request_is_active()
+	 */
+	I915_FENCE_FLAG_ACTIVE = DMA_FENCE_FLAG_USER_BITS,
+
+	/*
+	 * I915_FENCE_FLAG_PQUEUE - this request is ready for execution
+	 *
+	 * Using the scheduler, when a request is ready for execution it is put
+	 * into the priority queue, and removed from that queue when transferred
+	 * to the HW runlists. We want to track its membership within the
+	 * priority queue so that we can easily check before rescheduling.
+	 *
+	 * See i915_request_in_priority_queue()
+	 */
+	I915_FENCE_FLAG_PQUEUE,
+
+	/*
+	 * I915_FENCE_FLAG_HOLD - this request is currently on hold
+	 *
+	 * This request has been suspended, pending an ongoing investigation.
+	 */
+	I915_FENCE_FLAG_HOLD,
+
+	/*
+	 * I915_FENCE_FLAG_INITIAL_BREADCRUMB - this request has the initial
+	 * breadcrumb that marks the end of semaphore waits and start of the
+	 * user payload.
+	 */
+	I915_FENCE_FLAG_INITIAL_BREADCRUMB,
+
+	/*
+	 * I915_FENCE_FLAG_SIGNAL - this request is currently on signal_list
+	 *
+	 * Internal bookkeeping used by the breadcrumb code to track when
+	 * a request is on the various signal_list.
+	 */
+	I915_FENCE_FLAG_SIGNAL,
+
+	/*
+	 * I915_FENCE_FLAG_NOPREEMPT - this request should not be preempted
+	 *
+	 * The execution of some requests should not be interrupted. This is
+	 * a sensitive operation as it makes the request super important,
+	 * blocking other higher priority work. Abuse of this flag will
+	 * lead to quality of service issues.
+	 */
+	I915_FENCE_FLAG_NOPREEMPT,
+
+	/*
+	 * I915_FENCE_FLAG_SENTINEL - this request should be last in the queue
+	 *
+	 * A high priority sentinel request may be submitted to clear the
+	 * submission queue. As it will be the only request in-flight, upon
+	 * execution all other active requests will have been preempted and
+	 * unsubmitted. This preemptive pulse is used to re-evaluate the
+	 * in-flight requests, particularly in cases where an active context
+	 * is banned and those active requests need to be cancelled.
+	 */
+	I915_FENCE_FLAG_SENTINEL,
+
+	/*
+	 * I915_FENCE_FLAG_BOOST - upclock the gpu for this request
+	 *
+	 * Some requests are more important than others! In particular, a
+	 * request that the user is waiting on is typically required for
+	 * interactive latency, for which we want to minimise by upclocking
+	 * the GPU. Here we track such boost requests on a per-request basis.
+	 */
+	I915_FENCE_FLAG_BOOST,
+
+	/*
+	 * I915_FENCE_FLAG_SUBMIT_PARALLEL - request with a context in a
+	 * parent-child relationship (parallel submission, multi-lrc) should
+	 * trigger a submission to the GuC rather than just moving the context
+	 * tail.
+	 */
+	I915_FENCE_FLAG_SUBMIT_PARALLEL,
+
+	/*
+	 * I915_FENCE_FLAG_SKIP_PARALLEL - request with a context in a
+	 * parent-child relationship (parallel submission, multi-lrc) that
+	 * hit an error while generating requests in the execbuf IOCTL.
+	 * Indicates this request should be skipped as another request in
+	 * submission / relationship encoutered an error.
+	 */
+	I915_FENCE_FLAG_SKIP_PARALLEL,
+
+	/*
+	 * I915_FENCE_FLAG_COMPOSITE - Indicates fence is part of a composite
+	 * fence (dma_fence_array) and i915 generated for parallel submission.
+	 */
+	I915_FENCE_FLAG_COMPOSITE,
+};
+
+/**
+ * Request queue structure.
+ *
+ * The request queue allows us to note sequence numbers that have been emitted
+ * and may be associated with active buffers to be retired.
+ *
+ * By keeping this list, we can avoid having to do questionable sequence
+ * number comparisons on buffer last_read|write_seqno. It also allows an
+ * emission time to be associated with the request for tracking how far ahead
+ * of the GPU the submission is.
+ *
+ * When modifying this structure be very aware that we perform a lockless
+ * RCU lookup of it that may race against reallocation of the struct
+ * from the slab freelist. We intentionally do not zero the structure on
+ * allocation so that the lookup can use the dangling pointers (and is
+ * cogniscent that those pointers may be wrong). Instead, everything that
+ * needs to be initialised must be done so explicitly.
+ *
+ * The requests are reference counted.
+ */
+struct i915_request {
+	struct dma_fence fence;
+	spinlock_t lock;
+
+	struct drm_i915_private *i915;
+
+	/**
+	 * Context and ring buffer related to this request
+	 * Contexts are refcounted, so when this request is associated with a
+	 * context, we must increment the context's refcount, to guarantee that
+	 * it persists while any request is linked to it. Requests themselves
+	 * are also refcounted, so the request will only be freed when the last
+	 * reference to it is dismissed, and the code in
+	 * i915_request_free() will then decrement the refcount on the
+	 * context.
+	 */
+	struct intel_engine_cs *engine;
+	struct intel_context *context;
+	struct intel_ring *ring;
+	struct intel_timeline __rcu *timeline;
+
+	struct list_head signal_link;
+	struct llist_node signal_node;
+
+	/*
+	 * The rcu epoch of when this request was allocated. Used to judiciously
+	 * apply backpressure on future allocations to ensure that under
+	 * mempressure there is sufficient RCU ticks for us to reclaim our
+	 * RCU protected slabs.
+	 */
+	unsigned long rcustate;
+
+	/*
+	 * We pin the timeline->mutex while constructing the request to
+	 * ensure that no caller accidentally drops it during construction.
+	 * The timeline->mutex must be held to ensure that only this caller
+	 * can use the ring and manipulate the associated timeline during
+	 * construction.
+	 */
+	struct pin_cookie cookie;
+
+	/*
+	 * Fences for the various phases in the request's lifetime.
+	 *
+	 * The submit fence is used to await upon all of the request's
+	 * dependencies. When it is signaled, the request is ready to run.
+	 * It is used by the driver to then queue the request for execution.
+	 */
+	struct i915_sw_fence submit;
+	union {
+		wait_queue_entry_t submitq;
+		struct i915_sw_dma_fence_cb dmaq;
+		struct i915_request_duration_cb {
+			struct dma_fence_cb cb;
+			ktime_t emitted;
+		} duration;
+	};
+	struct llist_head execute_cb;
+	struct i915_sw_fence semaphore;
+	/**
+	 * @submit_work: complete submit fence from an IRQ if needed for
+	 * locking hierarchy reasons.
+	 */
+	struct irq_work submit_work;
+
+	/*
+	 * A list of everyone we wait upon, and everyone who waits upon us.
+	 * Even though we will not be submitted to the hardware before the
+	 * submit fence is signaled (it waits for all external events as well
+	 * as our own requests), the scheduler still needs to know the
+	 * dependency tree for the lifetime of the request (from execbuf
+	 * to retirement), i.e. bidirectional dependency information for the
+	 * request not tied to individual fences.
+	 */
+	struct i915_sched_node sched;
+	struct i915_dependency dep;
+	intel_engine_mask_t execution_mask;
+
+	/*
+	 * A convenience pointer to the current breadcrumb value stored in
+	 * the HW status page (or our timeline's local equivalent). The full
+	 * path would be rq->hw_context->ring->timeline->hwsp_seqno.
+	 */
+	const u32 *hwsp_seqno;
+
+	/** Position in the ring of the start of the request */
+	u32 head;
+
+	/** Position in the ring of the start of the user packets */
+	u32 infix;
+
+	/**
+	 * Position in the ring of the start of the postfix.
+	 * This is required to calculate the maximum available ring space
+	 * without overwriting the postfix.
+	 */
+	u32 postfix;
+
+	/** Position in the ring of the end of the whole request */
+	u32 tail;
+
+	/** Position in the ring of the end of any workarounds after the tail */
+	u32 wa_tail;
+
+	/** Preallocate space in the ring for the emitting the request */
+	u32 reserved_space;
+
+	/** Batch buffer pointer for selftest internal use. */
+	I915_SELFTEST_DECLARE(struct i915_vma *batch);
+
+	struct i915_vma_resource *batch_res;
+
+#if IS_ENABLED(CONFIG_DRM_I915_CAPTURE_ERROR)
+	/**
+	 * Additional buffers requested by userspace to be captured upon
+	 * a GPU hang. The vma/obj on this list are protected by their
+	 * active reference - all objects on this list must also be
+	 * on the active_list (of their final request).
+	 */
+	struct i915_capture_list *capture_list;
+#endif
+
+	/** Time at which this request was emitted, in jiffies. */
+	unsigned long emitted_jiffies;
+
+	/** timeline->request entry for this request */
+	struct list_head link;
+
+	/** Watchdog support fields. */
+	struct i915_request_watchdog {
+		struct llist_node link;
+		struct hrtimer timer;
+	} watchdog;
+
+	/**
+	 * @guc_fence_link: Requests may need to be stalled when using GuC
+	 * submission waiting for certain GuC operations to complete. If that is
+	 * the case, stalled requests are added to a per context list of stalled
+	 * requests. The below list_head is the link in that list. Protected by
+	 * ce->guc_state.lock.
+	 */
+	struct list_head guc_fence_link;
+
+	/**
+	 * @guc_prio: Priority level while the request is in flight. Differs
+	 * from i915 scheduler priority. See comment above
+	 * I915_SCHEDULER_CAP_STATIC_PRIORITY_MAP for details. Protected by
+	 * ce->guc_active.lock. Two special values (GUC_PRIO_INIT and
+	 * GUC_PRIO_FINI) outside the GuC priority range are used to indicate
+	 * if the priority has not been initialized yet or if no more updates
+	 * are possible because the request has completed.
+	 */
+#define	GUC_PRIO_INIT	0xff
+#define	GUC_PRIO_FINI	0xfe
+	u8 guc_prio;
+
+	I915_SELFTEST_DECLARE(struct {
+		struct list_head link;
+		unsigned long delay;
+	} mock;)
+};
+
+#define I915_FENCE_GFP (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN)
+
+extern const struct dma_fence_ops i915_fence_ops;
+
+static inline bool dma_fence_is_i915(const struct dma_fence *fence)
+{
+	return fence->ops == &i915_fence_ops;
+}
+
+struct kmem_cache *i915_request_slab_cache(void);
+
+struct i915_request * __must_check
+__i915_request_create(struct intel_context *ce, gfp_t gfp);
+struct i915_request * __must_check
+i915_request_create(struct intel_context *ce);
+
+void __i915_request_skip(struct i915_request *rq);
+bool i915_request_set_error_once(struct i915_request *rq, int error);
+struct i915_request *i915_request_mark_eio(struct i915_request *rq);
+
+struct i915_request *__i915_request_commit(struct i915_request *request);
+void __i915_request_queue(struct i915_request *rq,
+			  const struct i915_sched_attr *attr);
+void __i915_request_queue_bh(struct i915_request *rq);
+
+bool i915_request_retire(struct i915_request *rq);
+void i915_request_retire_upto(struct i915_request *rq);
+
+static inline struct i915_request *
+to_request(struct dma_fence *fence)
+{
+	/* We assume that NULL fence/request are interoperable */
+	BUILD_BUG_ON(offsetof(struct i915_request, fence) != 0);
+	GEM_BUG_ON(fence && !dma_fence_is_i915(fence));
+	return container_of(fence, struct i915_request, fence);
+}
+
+static inline struct i915_request *
+i915_request_get(struct i915_request *rq)
+{
+	return to_request(dma_fence_get(&rq->fence));
+}
+
+static inline struct i915_request *
+i915_request_get_rcu(struct i915_request *rq)
+{
+	return to_request(dma_fence_get_rcu(&rq->fence));
+}
+
+static inline void
+i915_request_put(struct i915_request *rq)
+{
+	dma_fence_put(&rq->fence);
+}
+
+int i915_request_await_object(struct i915_request *to,
+			      struct drm_i915_gem_object *obj,
+			      bool write);
+int i915_request_await_dma_fence(struct i915_request *rq,
+				 struct dma_fence *fence);
+int i915_request_await_deps(struct i915_request *rq, const struct i915_deps *deps);
+int i915_request_await_execution(struct i915_request *rq,
+				 struct dma_fence *fence);
+
+void i915_request_add(struct i915_request *rq);
+
+bool __i915_request_submit(struct i915_request *request);
+void i915_request_submit(struct i915_request *request);
+
+void __i915_request_unsubmit(struct i915_request *request);
+void i915_request_unsubmit(struct i915_request *request);
+
+void i915_request_cancel(struct i915_request *rq, int error);
+
+long i915_request_wait_timeout(struct i915_request *rq,
+			       unsigned int flags,
+			       long timeout)
+	__attribute__((nonnull(1)));
+
+long i915_request_wait(struct i915_request *rq,
+		       unsigned int flags,
+		       long timeout)
+	__attribute__((nonnull(1)));
+#define I915_WAIT_INTERRUPTIBLE	BIT(0)
+#define I915_WAIT_PRIORITY	BIT(1) /* small priority bump for the request */
+#define I915_WAIT_ALL		BIT(2) /* used by i915_gem_object_wait() */
+
+void i915_request_show(struct drm_printer *m,
+		       const struct i915_request *rq,
+		       const char *prefix,
+		       int indent);
+
+static inline bool i915_request_signaled(const struct i915_request *rq)
+{
+	/* The request may live longer than its HWSP, so check flags first! */
+	return test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags);
+}
+
+static inline bool i915_request_is_active(const struct i915_request *rq)
+{
+	return test_bit(I915_FENCE_FLAG_ACTIVE, &rq->fence.flags);
+}
+
+static inline bool i915_request_in_priority_queue(const struct i915_request *rq)
+{
+	return test_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags);
+}
+
+static inline bool
+i915_request_has_initial_breadcrumb(const struct i915_request *rq)
+{
+	return test_bit(I915_FENCE_FLAG_INITIAL_BREADCRUMB, &rq->fence.flags);
+}
+
+/**
+ * Returns true if seq1 is later than seq2.
+ */
+static inline bool i915_seqno_passed(u32 seq1, u32 seq2)
+{
+	return (s32)(seq1 - seq2) >= 0;
+}
+
+static inline u32 __hwsp_seqno(const struct i915_request *rq)
+{
+	const u32 *hwsp = READ_ONCE(rq->hwsp_seqno);
+
+	return READ_ONCE(*hwsp);
+}
+
+/**
+ * hwsp_seqno - the current breadcrumb value in the HW status page
+ * @rq: the request, to chase the relevant HW status page
+ *
+ * The emphasis in naming here is that hwsp_seqno() is not a property of the
+ * request, but an indication of the current HW state (associated with this
+ * request). Its value will change as the GPU executes more requests.
+ *
+ * Returns the current breadcrumb value in the associated HW status page (or
+ * the local timeline's equivalent) for this request. The request itself
+ * has the associated breadcrumb value of rq->fence.seqno, when the HW
+ * status page has that breadcrumb or later, this request is complete.
+ */
+static inline u32 hwsp_seqno(const struct i915_request *rq)
+{
+	u32 seqno;
+
+	rcu_read_lock(); /* the HWSP may be freed at runtime */
+	seqno = __hwsp_seqno(rq);
+	rcu_read_unlock();
+
+	return seqno;
+}
+
+static inline bool __i915_request_has_started(const struct i915_request *rq)
+{
+	return i915_seqno_passed(__hwsp_seqno(rq), rq->fence.seqno - 1);
+}
+
+/**
+ * i915_request_started - check if the request has begun being executed
+ * @rq: the request
+ *
+ * If the timeline is not using initial breadcrumbs, a request is
+ * considered started if the previous request on its timeline (i.e.
+ * context) has been signaled.
+ *
+ * If the timeline is using semaphores, it will also be emitting an
+ * "initial breadcrumb" after the semaphores are complete and just before
+ * it began executing the user payload. A request can therefore be active
+ * on the HW and not yet started as it is still busywaiting on its
+ * dependencies (via HW semaphores).
+ *
+ * If the request has started, its dependencies will have been signaled
+ * (either by fences or by semaphores) and it will have begun processing
+ * the user payload.
+ *
+ * However, even if a request has started, it may have been preempted and
+ * so no longer active, or it may have already completed.
+ *
+ * See also i915_request_is_active().
+ *
+ * Returns true if the request has begun executing the user payload, or
+ * has completed:
+ */
+static inline bool i915_request_started(const struct i915_request *rq)
+{
+	bool result;
+
+	if (i915_request_signaled(rq))
+		return true;
+
+	result = true;
+	rcu_read_lock(); /* the HWSP may be freed at runtime */
+	if (likely(!i915_request_signaled(rq)))
+		/* Remember: started but may have since been preempted! */
+		result = __i915_request_has_started(rq);
+	rcu_read_unlock();
+
+	return result;
+}
+
+/**
+ * i915_request_is_running - check if the request may actually be executing
+ * @rq: the request
+ *
+ * Returns true if the request is currently submitted to hardware, has passed
+ * its start point (i.e. the context is setup and not busywaiting). Note that
+ * it may no longer be running by the time the function returns!
+ */
+static inline bool i915_request_is_running(const struct i915_request *rq)
+{
+	bool result;
+
+	if (!i915_request_is_active(rq))
+		return false;
+
+	rcu_read_lock();
+	result = __i915_request_has_started(rq) && i915_request_is_active(rq);
+	rcu_read_unlock();
+
+	return result;
+}
+
+/**
+ * i915_request_is_ready - check if the request is ready for execution
+ * @rq: the request
+ *
+ * Upon construction, the request is instructed to wait upon various
+ * signals before it is ready to be executed by the HW. That is, we do
+ * not want to start execution and read data before it is written. In practice,
+ * this is controlled with a mixture of interrupts and semaphores. Once
+ * the submit fence is completed, the backend scheduler will place the
+ * request into its queue and from there submit it for execution. So we
+ * can detect when a request is eligible for execution (and is under control
+ * of the scheduler) by querying where it is in any of the scheduler's lists.
+ *
+ * Returns true if the request is ready for execution (it may be inflight),
+ * false otherwise.
+ */
+static inline bool i915_request_is_ready(const struct i915_request *rq)
+{
+	return !list_empty(&rq->sched.link);
+}
+
+static inline bool __i915_request_is_complete(const struct i915_request *rq)
+{
+	return i915_seqno_passed(__hwsp_seqno(rq), rq->fence.seqno);
+}
+
+static inline bool i915_request_completed(const struct i915_request *rq)
+{
+	bool result;
+
+	if (i915_request_signaled(rq))
+		return true;
+
+	result = true;
+	rcu_read_lock(); /* the HWSP may be freed at runtime */
+	if (likely(!i915_request_signaled(rq)))
+		result = __i915_request_is_complete(rq);
+	rcu_read_unlock();
+
+	return result;
+}
+
+static inline void i915_request_mark_complete(struct i915_request *rq)
+{
+	WRITE_ONCE(rq->hwsp_seqno, /* decouple from HWSP */
+		   (u32 *)&rq->fence.seqno);
+}
+
+static inline bool i915_request_has_waitboost(const struct i915_request *rq)
+{
+	return test_bit(I915_FENCE_FLAG_BOOST, &rq->fence.flags);
+}
+
+static inline bool i915_request_has_nopreempt(const struct i915_request *rq)
+{
+	/* Preemption should only be disabled very rarely */
+	return unlikely(test_bit(I915_FENCE_FLAG_NOPREEMPT, &rq->fence.flags));
+}
+
+static inline bool i915_request_has_sentinel(const struct i915_request *rq)
+{
+	return unlikely(test_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags));
+}
+
+static inline bool i915_request_on_hold(const struct i915_request *rq)
+{
+	return unlikely(test_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags));
+}
+
+static inline void i915_request_set_hold(struct i915_request *rq)
+{
+	set_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags);
+}
+
+static inline void i915_request_clear_hold(struct i915_request *rq)
+{
+	clear_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags);
+}
+
+static inline struct intel_timeline *
+i915_request_timeline(const struct i915_request *rq)
+{
+	/* Valid only while the request is being constructed (or retired). */
+	return rcu_dereference_protected(rq->timeline,
+					 lockdep_is_held(&rcu_access_pointer(rq->timeline)->mutex) ||
+					 test_bit(CONTEXT_IS_PARKING, &rq->context->flags));
+}
+
+static inline struct i915_gem_context *
+i915_request_gem_context(const struct i915_request *rq)
+{
+	/* Valid only while the request is being constructed (or retired). */
+	return rcu_dereference_protected(rq->context->gem_context, true);
+}
+
+static inline struct intel_timeline *
+i915_request_active_timeline(const struct i915_request *rq)
+{
+	/*
+	 * When in use during submission, we are protected by a guarantee that
+	 * the context/timeline is pinned and must remain pinned until after
+	 * this submission.
+	 */
+	return rcu_dereference_protected(rq->timeline,
+					 lockdep_is_held(&rq->engine->sched_engine->lock));
+}
+
+static inline u32
+i915_request_active_seqno(const struct i915_request *rq)
+{
+	u32 hwsp_phys_base =
+		page_mask_bits(i915_request_active_timeline(rq)->hwsp_offset);
+	u32 hwsp_relative_offset = offset_in_page(rq->hwsp_seqno);
+
+	/*
+	 * Because of wraparound, we cannot simply take tl->hwsp_offset,
+	 * but instead use the fact that the relative for vaddr is the
+	 * offset as for hwsp_offset. Take the top bits from tl->hwsp_offset
+	 * and combine them with the relative offset in rq->hwsp_seqno.
+	 *
+	 * As rw->hwsp_seqno is rewritten when signaled, this only works
+	 * when the request isn't signaled yet, but at that point you
+	 * no longer need the offset.
+	 */
+
+	return hwsp_phys_base + hwsp_relative_offset;
+}
+
+bool
+i915_request_active_engine(struct i915_request *rq,
+			   struct intel_engine_cs **active);
+
+void i915_request_notify_execute_cb_imm(struct i915_request *rq);
+
+enum i915_request_state {
+	I915_REQUEST_UNKNOWN = 0,
+	I915_REQUEST_COMPLETE,
+	I915_REQUEST_PENDING,
+	I915_REQUEST_QUEUED,
+	I915_REQUEST_ACTIVE,
+};
+
+enum i915_request_state i915_test_request_state(struct i915_request *rq);
+
+void i915_request_module_exit(void);
+int i915_request_module_init(void);
+
+#endif /* I915_REQUEST_H */