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/bits.h>
29 #include <linux/kref.h>
30
31 #include "gem/i915_gem_object_types.h"
32 #include "i915_active_types.h"
33
34 struct drm_i915_private;
35
36 enum fb_op_origin {
37 ORIGIN_CPU = 0,
38 ORIGIN_CS,
39 ORIGIN_FLIP,
40 ORIGIN_DIRTYFB,
41 ORIGIN_CURSOR_UPDATE,
42 };
43
44 struct intel_frontbuffer {
45 struct kref ref;
46 atomic_t bits;
47 struct i915_active write;
48 struct drm_i915_gem_object *obj;
49 struct rcu_head rcu;
50 };
51
52 /*
53 * Frontbuffer tracking bits. Set in obj->frontbuffer_bits while a gem bo is
54 * considered to be the frontbuffer for the given plane interface-wise. This
55 * doesn't mean that the hw necessarily already scans it out, but that any
56 * rendering (by the cpu or gpu) will land in the frontbuffer eventually.
57 *
58 * We have one bit per pipe and per scanout plane type.
59 */
60 #define INTEL_FRONTBUFFER_BITS_PER_PIPE 8
61 #define INTEL_FRONTBUFFER(pipe, plane_id) \
62 BIT((plane_id) + INTEL_FRONTBUFFER_BITS_PER_PIPE * (pipe));
63 #define INTEL_FRONTBUFFER_OVERLAY(pipe) \
64 BIT(INTEL_FRONTBUFFER_BITS_PER_PIPE - 1 + INTEL_FRONTBUFFER_BITS_PER_PIPE * (pipe))
65 #define INTEL_FRONTBUFFER_ALL_MASK(pipe) \
66 GENMASK(INTEL_FRONTBUFFER_BITS_PER_PIPE * ((pipe) + 1) - 1, \
67 INTEL_FRONTBUFFER_BITS_PER_PIPE * (pipe))
68
69 void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
70 unsigned frontbuffer_bits);
71 void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
72 unsigned frontbuffer_bits);
73 void intel_frontbuffer_flip(struct drm_i915_private *i915,
74 unsigned frontbuffer_bits);
75
76 void intel_frontbuffer_put(struct intel_frontbuffer *front);
77
78 static inline struct intel_frontbuffer *
__intel_frontbuffer_get(const struct drm_i915_gem_object * obj)79 __intel_frontbuffer_get(const struct drm_i915_gem_object *obj)
80 {
81 struct intel_frontbuffer *front;
82
83 if (likely(!rcu_access_pointer(obj->frontbuffer)))
84 return NULL;
85
86 rcu_read_lock();
87 do {
88 front = rcu_dereference(obj->frontbuffer);
89 if (!front)
90 break;
91
92 if (unlikely(!kref_get_unless_zero(&front->ref)))
93 continue;
94
95 if (likely(front == rcu_access_pointer(obj->frontbuffer)))
96 break;
97
98 intel_frontbuffer_put(front);
99 } while (1);
100 rcu_read_unlock();
101
102 return front;
103 }
104
105 struct intel_frontbuffer *
106 intel_frontbuffer_get(struct drm_i915_gem_object *obj);
107
108 void __intel_fb_invalidate(struct intel_frontbuffer *front,
109 enum fb_op_origin origin,
110 unsigned int frontbuffer_bits);
111
112 /**
113 * intel_frontbuffer_invalidate - invalidate frontbuffer object
114 * @front: GEM object to invalidate
115 * @origin: which operation caused the invalidation
116 *
117 * This function gets called every time rendering on the given object starts and
118 * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must
119 * be invalidated. For ORIGIN_CS any subsequent invalidation will be delayed
120 * until the rendering completes or a flip on this frontbuffer plane is
121 * scheduled.
122 */
intel_frontbuffer_invalidate(struct intel_frontbuffer * front,enum fb_op_origin origin)123 static inline bool intel_frontbuffer_invalidate(struct intel_frontbuffer *front,
124 enum fb_op_origin origin)
125 {
126 unsigned int frontbuffer_bits;
127
128 if (!front)
129 return false;
130
131 frontbuffer_bits = atomic_read(&front->bits);
132 if (!frontbuffer_bits)
133 return false;
134
135 __intel_fb_invalidate(front, origin, frontbuffer_bits);
136 return true;
137 }
138
139 void __intel_fb_flush(struct intel_frontbuffer *front,
140 enum fb_op_origin origin,
141 unsigned int frontbuffer_bits);
142
143 /**
144 * intel_frontbuffer_flush - flush frontbuffer object
145 * @front: GEM object to flush
146 * @origin: which operation caused the flush
147 *
148 * This function gets called every time rendering on the given object has
149 * completed and frontbuffer caching can be started again.
150 */
intel_frontbuffer_flush(struct intel_frontbuffer * front,enum fb_op_origin origin)151 static inline void intel_frontbuffer_flush(struct intel_frontbuffer *front,
152 enum fb_op_origin origin)
153 {
154 unsigned int frontbuffer_bits;
155
156 if (!front)
157 return;
158
159 frontbuffer_bits = atomic_read(&front->bits);
160 if (!frontbuffer_bits)
161 return;
162
163 __intel_fb_flush(front, origin, frontbuffer_bits);
164 }
165
166 void intel_frontbuffer_track(struct intel_frontbuffer *old,
167 struct intel_frontbuffer *new,
168 unsigned int frontbuffer_bits);
169
170 #endif /* __INTEL_FRONTBUFFER_H__ */
171