1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2016 Intel Corporation
5  */
6 
7 #ifndef __I915_TIMELINE_TYPES_H__
8 #define __I915_TIMELINE_TYPES_H__
9 
10 #include <linux/list.h>
11 #include <linux/kref.h>
12 #include <linux/mutex.h>
13 #include <linux/types.h>
14 
15 #include "i915_active_types.h"
16 
17 struct drm_i915_private;
18 struct i915_vma;
19 struct intel_timeline_cacheline;
20 struct i915_syncmap;
21 
22 struct intel_timeline {
23 	u64 fence_context;
24 	u32 seqno;
25 
26 	struct mutex mutex; /* protects the flow of requests */
27 
28 	/*
29 	 * pin_count and active_count track essentially the same thing:
30 	 * How many requests are in flight or may be under construction.
31 	 *
32 	 * We need two distinct counters so that we can assign different
33 	 * lifetimes to the events for different use-cases. For example,
34 	 * we want to permanently keep the timeline pinned for the kernel
35 	 * context so that we can issue requests at any time without having
36 	 * to acquire space in the GGTT. However, we want to keep tracking
37 	 * the activity (to be able to detect when we become idle) along that
38 	 * permanently pinned timeline and so end up requiring two counters.
39 	 *
40 	 * Note that the active_count is protected by the intel_timeline.mutex,
41 	 * but the pin_count is protected by a combination of serialisation
42 	 * from the intel_context caller plus internal atomicity.
43 	 */
44 	atomic_t pin_count;
45 	unsigned int active_count;
46 
47 	const u32 *hwsp_seqno;
48 	struct i915_vma *hwsp_ggtt;
49 	u32 hwsp_offset;
50 
51 	struct intel_timeline_cacheline *hwsp_cacheline;
52 
53 	bool has_initial_breadcrumb;
54 
55 	/**
56 	 * List of breadcrumbs associated with GPU requests currently
57 	 * outstanding.
58 	 */
59 	struct list_head requests;
60 
61 	/* Contains an RCU guarded pointer to the last request. No reference is
62 	 * held to the request, users must carefully acquire a reference to
63 	 * the request using i915_active_request_get_request_rcu(), or hold the
64 	 * struct_mutex.
65 	 */
66 	struct i915_active_request last_request;
67 
68 	/**
69 	 * We track the most recent seqno that we wait on in every context so
70 	 * that we only have to emit a new await and dependency on a more
71 	 * recent sync point. As the contexts may be executed out-of-order, we
72 	 * have to track each individually and can not rely on an absolute
73 	 * global_seqno. When we know that all tracked fences are completed
74 	 * (i.e. when the driver is idle), we know that the syncmap is
75 	 * redundant and we can discard it without loss of generality.
76 	 */
77 	struct i915_syncmap *sync;
78 
79 	struct list_head link;
80 	struct intel_gt *gt;
81 
82 	struct kref kref;
83 };
84 
85 #endif /* __I915_TIMELINE_TYPES_H__ */
86