1 /* $NetBSD: intel_frontbuffer.h,v 1.2 2021/12/18 23:45:30 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 2014-2016 Intel Corporation
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
15 * Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
23 * IN THE SOFTWARE.
24 */
25
26 #ifndef __INTEL_FRONTBUFFER_H__
27 #define __INTEL_FRONTBUFFER_H__
28
29 #include <linux/atomic.h>
30 #include <linux/kref.h>
31
32 #include "gem/i915_gem_object_types.h"
33 #include "i915_active.h"
34
35 struct drm_i915_private;
36
37 enum fb_op_origin {
38 ORIGIN_GTT,
39 ORIGIN_CPU,
40 ORIGIN_CS,
41 ORIGIN_FLIP,
42 ORIGIN_DIRTYFB,
43 };
44
45 struct intel_frontbuffer {
46 struct kref ref;
47 atomic_t bits;
48 struct i915_active write;
49 struct drm_i915_gem_object *obj;
50 struct rcu_head rcu;
51 };
52
53 void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
54 unsigned frontbuffer_bits);
55 void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
56 unsigned frontbuffer_bits);
57 void intel_frontbuffer_flip(struct drm_i915_private *i915,
58 unsigned frontbuffer_bits);
59
60 void intel_frontbuffer_put(struct intel_frontbuffer *front);
61
62 static inline struct intel_frontbuffer *
__intel_frontbuffer_get(const struct drm_i915_gem_object * obj)63 __intel_frontbuffer_get(const struct drm_i915_gem_object *obj)
64 {
65 struct intel_frontbuffer *front;
66
67 if (likely(!rcu_access_pointer(obj->frontbuffer)))
68 return NULL;
69
70 rcu_read_lock();
71 do {
72 front = rcu_dereference(obj->frontbuffer);
73 if (!front)
74 break;
75
76 if (unlikely(!kref_get_unless_zero(&front->ref)))
77 continue;
78
79 if (likely(front == rcu_access_pointer(obj->frontbuffer)))
80 break;
81
82 intel_frontbuffer_put(front);
83 } while (1);
84 rcu_read_unlock();
85
86 return front;
87 }
88
89 struct intel_frontbuffer *
90 intel_frontbuffer_get(struct drm_i915_gem_object *obj);
91
92 void __intel_fb_invalidate(struct intel_frontbuffer *front,
93 enum fb_op_origin origin,
94 unsigned int frontbuffer_bits);
95
96 /**
97 * intel_frontbuffer_invalidate - invalidate frontbuffer object
98 * @front: GEM object to invalidate
99 * @origin: which operation caused the invalidation
100 *
101 * This function gets called every time rendering on the given object starts and
102 * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must
103 * be invalidated. For ORIGIN_CS any subsequent invalidation will be delayed
104 * until the rendering completes or a flip on this frontbuffer plane is
105 * scheduled.
106 */
intel_frontbuffer_invalidate(struct intel_frontbuffer * front,enum fb_op_origin origin)107 static inline bool intel_frontbuffer_invalidate(struct intel_frontbuffer *front,
108 enum fb_op_origin origin)
109 {
110 unsigned int frontbuffer_bits;
111
112 if (!front)
113 return false;
114
115 frontbuffer_bits = atomic_read(&front->bits);
116 if (!frontbuffer_bits)
117 return false;
118
119 __intel_fb_invalidate(front, origin, frontbuffer_bits);
120 return true;
121 }
122
123 void __intel_fb_flush(struct intel_frontbuffer *front,
124 enum fb_op_origin origin,
125 unsigned int frontbuffer_bits);
126
127 /**
128 * intel_frontbuffer_flush - flush frontbuffer object
129 * @front: GEM object to flush
130 * @origin: which operation caused the flush
131 *
132 * This function gets called every time rendering on the given object has
133 * completed and frontbuffer caching can be started again.
134 */
intel_frontbuffer_flush(struct intel_frontbuffer * front,enum fb_op_origin origin)135 static inline void intel_frontbuffer_flush(struct intel_frontbuffer *front,
136 enum fb_op_origin origin)
137 {
138 unsigned int frontbuffer_bits;
139
140 if (!front)
141 return;
142
143 frontbuffer_bits = atomic_read(&front->bits);
144 if (!frontbuffer_bits)
145 return;
146
147 __intel_fb_flush(front, origin, frontbuffer_bits);
148 }
149
150 void intel_frontbuffer_track(struct intel_frontbuffer *old,
151 struct intel_frontbuffer *new,
152 unsigned int frontbuffer_bits);
153
154 #endif /* __INTEL_FRONTBUFFER_H__ */
155