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__ */