Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 205 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_scheduler_types.h b/drivers/gpu/drm/i915/i915_scheduler_types.h
new file mode 100644
index 0000000000..b0a1b58c78
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_scheduler_types.h
@@ -0,0 +1,205 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2018 Intel Corporation
+ */
+
+#ifndef _I915_SCHEDULER_TYPES_H_
+#define _I915_SCHEDULER_TYPES_H_
+
+#include <linux/list.h>
+
+#include "gt/intel_engine_types.h"
+#include "i915_priolist_types.h"
+
+struct drm_i915_private;
+struct i915_request;
+struct intel_engine_cs;
+
+struct i915_sched_attr {
+	/**
+	 * @priority: execution and service priority
+	 *
+	 * All clients are equal, but some are more equal than others!
+	 *
+	 * Requests from a context with a greater (more positive) value of
+	 * @priority will be executed before those with a lower @priority
+	 * value, forming a simple QoS.
+	 *
+	 * The &drm_i915_private.kernel_context is assigned the lowest priority.
+	 */
+	int priority;
+};
+
+/*
+ * "People assume that time is a strict progression of cause to effect, but
+ * actually, from a nonlinear, non-subjective viewpoint, it's more like a big
+ * ball of wibbly-wobbly, timey-wimey ... stuff." -The Doctor, 2015
+ *
+ * Requests exist in a complex web of interdependencies. Each request
+ * has to wait for some other request to complete before it is ready to be run
+ * (e.g. we have to wait until the pixels have been rendering into a texture
+ * before we can copy from it). We track the readiness of a request in terms
+ * of fences, but we also need to keep the dependency tree for the lifetime
+ * of the request (beyond the life of an individual fence). We use the tree
+ * at various points to reorder the requests whilst keeping the requests
+ * in order with respect to their various dependencies.
+ *
+ * There is no active component to the "scheduler". As we know the dependency
+ * DAG of each request, we are able to insert it into a sorted queue when it
+ * is ready, and are able to reorder its portion of the graph to accommodate
+ * dynamic priority changes.
+ *
+ * Ok, there is now one active element to the "scheduler" in the backends.
+ * We let a new context run for a small amount of time before re-evaluating
+ * the run order. As we re-evaluate, we maintain the strict ordering of
+ * dependencies, but attempt to rotate the active contexts (the current context
+ * is put to the back of its priority queue, then reshuffling its dependents).
+ * This provides minimal timeslicing and prevents a userspace hog (e.g.
+ * something waiting on a user semaphore [VkEvent]) from denying service to
+ * others.
+ */
+struct i915_sched_node {
+	struct list_head signalers_list; /* those before us, we depend upon */
+	struct list_head waiters_list; /* those after us, they depend upon us */
+	struct list_head link;
+	struct i915_sched_attr attr;
+	unsigned int flags;
+#define I915_SCHED_HAS_EXTERNAL_CHAIN	BIT(0)
+	intel_engine_mask_t semaphores;
+};
+
+struct i915_dependency {
+	struct i915_sched_node *signaler;
+	struct i915_sched_node *waiter;
+	struct list_head signal_link;
+	struct list_head wait_link;
+	struct list_head dfs_link;
+	unsigned long flags;
+#define I915_DEPENDENCY_ALLOC		BIT(0)
+#define I915_DEPENDENCY_EXTERNAL	BIT(1)
+#define I915_DEPENDENCY_WEAK		BIT(2)
+};
+
+#define for_each_waiter(p__, rq__) \
+	list_for_each_entry_lockless(p__, \
+				     &(rq__)->sched.waiters_list, \
+				     wait_link)
+
+#define for_each_signaler(p__, rq__) \
+	list_for_each_entry_rcu(p__, \
+				&(rq__)->sched.signalers_list, \
+				signal_link)
+
+/**
+ * struct i915_sched_engine - scheduler engine
+ *
+ * A schedule engine represents a submission queue with different priority
+ * bands. It contains all the common state (relative to the backend) to queue,
+ * track, and submit a request.
+ *
+ * This object at the moment is quite i915 specific but will transition into a
+ * container for the drm_gpu_scheduler plus a few other variables once the i915
+ * is integrated with the DRM scheduler.
+ */
+struct i915_sched_engine {
+	/**
+	 * @ref: reference count of schedule engine object
+	 */
+	struct kref ref;
+
+	/**
+	 * @lock: protects requests in priority lists, requests, hold and
+	 * tasklet while running
+	 */
+	spinlock_t lock;
+
+	/**
+	 * @requests: list of requests inflight on this schedule engine
+	 */
+	struct list_head requests;
+
+	/**
+	 * @hold: list of ready requests, but on hold
+	 */
+	struct list_head hold;
+
+	/**
+	 * @tasklet: softirq tasklet for submission
+	 */
+	struct tasklet_struct tasklet;
+
+	/**
+	 * @default_priolist: priority list for I915_PRIORITY_NORMAL
+	 */
+	struct i915_priolist default_priolist;
+
+	/**
+	 * @queue_priority_hint: Highest pending priority.
+	 *
+	 * When we add requests into the queue, or adjust the priority of
+	 * executing requests, we compute the maximum priority of those
+	 * pending requests. We can then use this value to determine if
+	 * we need to preempt the executing requests to service the queue.
+	 * However, since the we may have recorded the priority of an inflight
+	 * request we wanted to preempt but since completed, at the time of
+	 * dequeuing the priority hint may no longer may match the highest
+	 * available request priority.
+	 */
+	int queue_priority_hint;
+
+	/**
+	 * @queue: queue of requests, in priority lists
+	 */
+	struct rb_root_cached queue;
+
+	/**
+	 * @no_priolist: priority lists disabled
+	 */
+	bool no_priolist;
+
+	/**
+	 * @private_data: private data of the submission backend
+	 */
+	void *private_data;
+
+	/**
+	 * @destroy: destroy schedule engine / cleanup in backend
+	 */
+	void	(*destroy)(struct kref *kref);
+
+	/**
+	 * @disabled: check if backend has disabled submission
+	 */
+	bool	(*disabled)(struct i915_sched_engine *sched_engine);
+
+	/**
+	 * @kick_backend: kick backend after a request's priority has changed
+	 */
+	void	(*kick_backend)(const struct i915_request *rq,
+				int prio);
+
+	/**
+	 * @bump_inflight_request_prio: update priority of an inflight request
+	 */
+	void	(*bump_inflight_request_prio)(struct i915_request *rq,
+					      int prio);
+
+	/**
+	 * @retire_inflight_request_prio: indicate request is retired to
+	 * priority tracking
+	 */
+	void	(*retire_inflight_request_prio)(struct i915_request *rq);
+
+	/**
+	 * @schedule: adjust priority of request
+	 *
+	 * Call when the priority on a request has changed and it and its
+	 * dependencies may need rescheduling. Note the request itself may
+	 * not be ready to run!
+	 */
+	void	(*schedule)(struct i915_request *request,
+			    const struct i915_sched_attr *attr);
+};
+
+#endif /* _I915_SCHEDULER_TYPES_H_ */