xref: /linux/drivers/gpu/drm/i915/display/intel_frontbuffer.h (revision 79d2e1919a2728ef49d938eb20ebd5903c14dfb0)
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_gem_object;
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_gem_object *obj;
49 	struct rcu_head rcu;
50 
51 	struct work_struct flush_work;
52 };
53 
54 /*
55  * Frontbuffer tracking bits. Set in obj->frontbuffer_bits while a gem bo is
56  * considered to be the frontbuffer for the given plane interface-wise. This
57  * doesn't mean that the hw necessarily already scans it out, but that any
58  * rendering (by the cpu or gpu) will land in the frontbuffer eventually.
59  *
60  * We have one bit per pipe and per scanout plane type.
61  */
62 #define INTEL_FRONTBUFFER_BITS_PER_PIPE 8
63 #define INTEL_FRONTBUFFER(pipe, plane_id) \
64 	BIT((plane_id) + INTEL_FRONTBUFFER_BITS_PER_PIPE * (pipe));
65 #define INTEL_FRONTBUFFER_OVERLAY(pipe) \
66 	BIT(INTEL_FRONTBUFFER_BITS_PER_PIPE - 1 + INTEL_FRONTBUFFER_BITS_PER_PIPE * (pipe))
67 #define INTEL_FRONTBUFFER_ALL_MASK(pipe) \
68 	GENMASK(INTEL_FRONTBUFFER_BITS_PER_PIPE * ((pipe) + 1) - 1,	\
69 		INTEL_FRONTBUFFER_BITS_PER_PIPE * (pipe))
70 
71 void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
72 				    unsigned frontbuffer_bits);
73 void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
74 				     unsigned frontbuffer_bits);
75 void intel_frontbuffer_flip(struct drm_i915_private *i915,
76 			    unsigned frontbuffer_bits);
77 
78 void intel_frontbuffer_put(struct intel_frontbuffer *front);
79 
80 struct intel_frontbuffer *
81 intel_frontbuffer_get(struct drm_gem_object *obj);
82 
83 void __intel_fb_invalidate(struct intel_frontbuffer *front,
84 			   enum fb_op_origin origin,
85 			   unsigned int frontbuffer_bits);
86 
87 /**
88  * intel_frontbuffer_invalidate - invalidate frontbuffer object
89  * @front: GEM object to invalidate
90  * @origin: which operation caused the invalidation
91  *
92  * This function gets called every time rendering on the given object starts and
93  * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must
94  * be invalidated. For ORIGIN_CS any subsequent invalidation will be delayed
95  * until the rendering completes or a flip on this frontbuffer plane is
96  * scheduled.
97  */
98 static inline bool intel_frontbuffer_invalidate(struct intel_frontbuffer *front,
99 						enum fb_op_origin origin)
100 {
101 	unsigned int frontbuffer_bits;
102 
103 	if (!front)
104 		return false;
105 
106 	frontbuffer_bits = atomic_read(&front->bits);
107 	if (!frontbuffer_bits)
108 		return false;
109 
110 	__intel_fb_invalidate(front, origin, frontbuffer_bits);
111 	return true;
112 }
113 
114 void __intel_fb_flush(struct intel_frontbuffer *front,
115 		      enum fb_op_origin origin,
116 		      unsigned int frontbuffer_bits);
117 
118 /**
119  * intel_frontbuffer_flush - flush frontbuffer object
120  * @front: GEM object to flush
121  * @origin: which operation caused the flush
122  *
123  * This function gets called every time rendering on the given object has
124  * completed and frontbuffer caching can be started again.
125  */
126 static inline void intel_frontbuffer_flush(struct intel_frontbuffer *front,
127 					   enum fb_op_origin origin)
128 {
129 	unsigned int frontbuffer_bits;
130 
131 	if (!front)
132 		return;
133 
134 	frontbuffer_bits = atomic_read(&front->bits);
135 	if (!frontbuffer_bits)
136 		return;
137 
138 	__intel_fb_flush(front, origin, frontbuffer_bits);
139 }
140 
141 void intel_frontbuffer_queue_flush(struct intel_frontbuffer *front);
142 
143 void intel_frontbuffer_track(struct intel_frontbuffer *old,
144 			     struct intel_frontbuffer *new,
145 			     unsigned int frontbuffer_bits);
146 
147 #endif /* __INTEL_FRONTBUFFER_H__ */
148