1/* SPDX-License-Identifier: MIT */
2/*
3 * Copyright �� 2016 Intel Corporation
4 */
5
6#ifndef __I915_TIMELINE_TYPES_H__
7#define __I915_TIMELINE_TYPES_H__
8
9#include <linux/list.h>
10#include <linux/kref.h>
11#include <linux/mutex.h>
12#include <linux/rcupdate.h>
13#include <linux/types.h>
14
15#include "i915_active_types.h"
16
17struct i915_vma;
18struct i915_syncmap;
19struct intel_gt;
20
21struct intel_timeline {
22	u64 fence_context;
23	u32 seqno;
24
25	struct mutex mutex; /* protects the flow of requests */
26
27	/*
28	 * pin_count and active_count track essentially the same thing:
29	 * How many requests are in flight or may be under construction.
30	 *
31	 * We need two distinct counters so that we can assign different
32	 * lifetimes to the events for different use-cases. For example,
33	 * we want to permanently keep the timeline pinned for the kernel
34	 * context so that we can issue requests at any time without having
35	 * to acquire space in the GGTT. However, we want to keep tracking
36	 * the activity (to be able to detect when we become idle) along that
37	 * permanently pinned timeline and so end up requiring two counters.
38	 *
39	 * Note that the active_count is protected by the intel_timeline.mutex,
40	 * but the pin_count is protected by a combination of serialisation
41	 * from the intel_context caller plus internal atomicity.
42	 */
43	atomic_t pin_count;
44	atomic_t active_count;
45
46	void *hwsp_map;
47	const u32 *hwsp_seqno;
48	struct i915_vma *hwsp_ggtt;
49	u32 hwsp_offset;
50
51	bool has_initial_breadcrumb;
52
53	/**
54	 * List of breadcrumbs associated with GPU requests currently
55	 * outstanding.
56	 */
57	struct list_head requests;
58
59	/*
60	 * Contains an RCU guarded pointer to the last request. No reference is
61	 * held to the request, users must carefully acquire a reference to
62	 * the request using i915_active_fence_get(), or manage the RCU
63	 * protection themselves (cf the i915_active_fence API).
64	 */
65	struct i915_active_fence last_request;
66
67	struct i915_active active;
68
69	/** A chain of completed timelines ready for early retirement. */
70	struct intel_timeline *retire;
71
72	/**
73	 * We track the most recent seqno that we wait on in every context so
74	 * that we only have to emit a new await and dependency on a more
75	 * recent sync point. As the contexts may be executed out-of-order, we
76	 * have to track each individually and can not rely on an absolute
77	 * global_seqno. When we know that all tracked fences are completed
78	 * (i.e. when the driver is idle), we know that the syncmap is
79	 * redundant and we can discard it without loss of generality.
80	 */
81	struct i915_syncmap *sync;
82
83	struct list_head link;
84	struct intel_gt *gt;
85
86	struct list_head engine_link;
87
88	struct kref kref;
89	struct rcu_head rcu;
90};
91
92#endif /* __I915_TIMELINE_TYPES_H__ */
93