intel_frontbuffer.h revision 1.1 
1/*
2 * Copyright (c) 2014-2016 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24#ifndef __INTEL_FRONTBUFFER_H__
25#define __INTEL_FRONTBUFFER_H__
26
27#include <linux/atomic.h>
28#include <linux/kref.h>
29
30#include "gem/i915_gem_object_types.h"
31#include "i915_active.h"
32
33struct drm_i915_private;
34
35enum fb_op_origin {
36	ORIGIN_GTT,
37	ORIGIN_CPU,
38	ORIGIN_CS,
39	ORIGIN_FLIP,
40	ORIGIN_DIRTYFB,
41};
42
43struct intel_frontbuffer {
44	struct kref ref;
45	atomic_t bits;
46	struct i915_active write;
47	struct drm_i915_gem_object *obj;
48	struct rcu_head rcu;
49};
50
51void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
52				    unsigned frontbuffer_bits);
53void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
54				     unsigned frontbuffer_bits);
55void intel_frontbuffer_flip(struct drm_i915_private *i915,
56			    unsigned frontbuffer_bits);
57
58void intel_frontbuffer_put(struct intel_frontbuffer *front);
59
60static inline struct intel_frontbuffer *
61__intel_frontbuffer_get(const struct drm_i915_gem_object *obj)
62{
63	struct intel_frontbuffer *front;
64
65	if (likely(!rcu_access_pointer(obj->frontbuffer)))
66		return NULL;
67
68	rcu_read_lock();
69	do {
70		front = rcu_dereference(obj->frontbuffer);
71		if (!front)
72			break;
73
74		if (unlikely(!kref_get_unless_zero(&front->ref)))
75			continue;
76
77		if (likely(front == rcu_access_pointer(obj->frontbuffer)))
78			break;
79
80		intel_frontbuffer_put(front);
81	} while (1);
82	rcu_read_unlock();
83
84	return front;
85}
86
87struct intel_frontbuffer *
88intel_frontbuffer_get(struct drm_i915_gem_object *obj);
89
90void __intel_fb_invalidate(struct intel_frontbuffer *front,
91			   enum fb_op_origin origin,
92			   unsigned int frontbuffer_bits);
93
94/**
95 * intel_frontbuffer_invalidate - invalidate frontbuffer object
96 * @front: GEM object to invalidate
97 * @origin: which operation caused the invalidation
98 *
99 * This function gets called every time rendering on the given object starts and
100 * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must
101 * be invalidated. For ORIGIN_CS any subsequent invalidation will be delayed
102 * until the rendering completes or a flip on this frontbuffer plane is
103 * scheduled.
104 */
105static inline bool intel_frontbuffer_invalidate(struct intel_frontbuffer *front,
106						enum fb_op_origin origin)
107{
108	unsigned int frontbuffer_bits;
109
110	if (!front)
111		return false;
112
113	frontbuffer_bits = atomic_read(&front->bits);
114	if (!frontbuffer_bits)
115		return false;
116
117	__intel_fb_invalidate(front, origin, frontbuffer_bits);
118	return true;
119}
120
121void __intel_fb_flush(struct intel_frontbuffer *front,
122		      enum fb_op_origin origin,
123		      unsigned int frontbuffer_bits);
124
125/**
126 * intel_frontbuffer_flush - flush frontbuffer object
127 * @front: GEM object to flush
128 * @origin: which operation caused the flush
129 *
130 * This function gets called every time rendering on the given object has
131 * completed and frontbuffer caching can be started again.
132 */
133static inline void intel_frontbuffer_flush(struct intel_frontbuffer *front,
134					   enum fb_op_origin origin)
135{
136	unsigned int frontbuffer_bits;
137
138	if (!front)
139		return;
140
141	frontbuffer_bits = atomic_read(&front->bits);
142	if (!frontbuffer_bits)
143		return;
144
145	__intel_fb_flush(front, origin, frontbuffer_bits);
146}
147
148void intel_frontbuffer_track(struct intel_frontbuffer *old,
149			     struct intel_frontbuffer *new,
150			     unsigned int frontbuffer_bits);
151
152#endif /* __INTEL_FRONTBUFFER_H__ */
153