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