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1/*
2 * Copyright © 2014 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
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Daniel Vetter <daniel.vetter@ffwll.ch>
25 */
26
27/**
28 * DOC: frontbuffer tracking
29 *
30 * Many features require us to track changes to the currently active
31 * frontbuffer, especially rendering targeted at the frontbuffer.
32 *
33 * To be able to do so GEM tracks frontbuffers using a bitmask for all possible
34 * frontbuffer slots through i915_gem_track_fb(). The function in this file are
35 * then called when the contents of the frontbuffer are invalidated, when
36 * frontbuffer rendering has stopped again to flush out all the changes and when
37 * the frontbuffer is exchanged with a flip. Subsystems interested in
38 * frontbuffer changes (e.g. PSR, FBC, DRRS) should directly put their callbacks
39 * into the relevant places and filter for the frontbuffer slots that they are
40 * interested int.
41 *
42 * On a high level there are two types of powersaving features. The first one
43 * work like a special cache (FBC and PSR) and are interested when they should
44 * stop caching and when to restart caching. This is done by placing callbacks
45 * into the invalidate and the flush functions: At invalidate the caching must
46 * be stopped and at flush time it can be restarted. And maybe they need to know
47 * when the frontbuffer changes (e.g. when the hw doesn't initiate an invalidate
48 * and flush on its own) which can be achieved with placing callbacks into the
49 * flip functions.
50 *
51 * The other type of display power saving feature only cares about busyness
52 * (e.g. DRRS). In that case all three (invalidate, flush and flip) indicate
53 * busyness. There is no direct way to detect idleness. Instead an idle timer
54 * work delayed work should be started from the flush and flip functions and
55 * cancelled as soon as busyness is detected.
56 *
57 * Note that there's also an older frontbuffer activity tracking scheme which
58 * just tracks general activity. This is done by the various mark_busy and
59 * mark_idle functions. For display power management features using these
60 * functions is deprecated and should be avoided.
61 */
62
63
64#include "i915_drv.h"
65#include "intel_dp.h"
66#include "intel_drv.h"
67#include "intel_fbc.h"
68#include "intel_frontbuffer.h"
69#include "intel_psr.h"
70
71void __intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
72 enum fb_op_origin origin,
73 unsigned int frontbuffer_bits)
74{
75 struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
76
77 if (origin == ORIGIN_CS) {
78 spin_lock(&dev_priv->fb_tracking.lock);
79 dev_priv->fb_tracking.busy_bits |= frontbuffer_bits;
80 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
81 spin_unlock(&dev_priv->fb_tracking.lock);
82 }
83
84 might_sleep();
85 intel_psr_invalidate(dev_priv, frontbuffer_bits, origin);
86 intel_edp_drrs_invalidate(dev_priv, frontbuffer_bits);
87 intel_fbc_invalidate(dev_priv, frontbuffer_bits, origin);
88}
89
90/**
91 * intel_frontbuffer_flush - flush frontbuffer
92 * @dev_priv: i915 device
93 * @frontbuffer_bits: frontbuffer plane tracking bits
94 * @origin: which operation caused the flush
95 *
96 * This function gets called every time rendering on the given planes has
97 * completed and frontbuffer caching can be started again. Flushes will get
98 * delayed if they're blocked by some outstanding asynchronous rendering.
99 *
100 * Can be called without any locks held.
101 */
102static void intel_frontbuffer_flush(struct drm_i915_private *dev_priv,
103 unsigned frontbuffer_bits,
104 enum fb_op_origin origin)
105{
106 /* Delay flushing when rings are still busy.*/
107 spin_lock(&dev_priv->fb_tracking.lock);
108 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits;
109 spin_unlock(&dev_priv->fb_tracking.lock);
110
111 if (!frontbuffer_bits)
112 return;
113
114 might_sleep();
115 intel_edp_drrs_flush(dev_priv, frontbuffer_bits);
116 intel_psr_flush(dev_priv, frontbuffer_bits, origin);
117 intel_fbc_flush(dev_priv, frontbuffer_bits, origin);
118}
119
120void __intel_fb_obj_flush(struct drm_i915_gem_object *obj,
121 enum fb_op_origin origin,
122 unsigned int frontbuffer_bits)
123{
124 struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
125
126 if (origin == ORIGIN_CS) {
127 spin_lock(&dev_priv->fb_tracking.lock);
128 /* Filter out new bits since rendering started. */
129 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits;
130 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
131 spin_unlock(&dev_priv->fb_tracking.lock);
132 }
133
134 if (frontbuffer_bits)
135 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, origin);
136}
137
138/**
139 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip
140 * @dev_priv: i915 device
141 * @frontbuffer_bits: frontbuffer plane tracking bits
142 *
143 * This function gets called after scheduling a flip on @obj. The actual
144 * frontbuffer flushing will be delayed until completion is signalled with
145 * intel_frontbuffer_flip_complete. If an invalidate happens in between this
146 * flush will be cancelled.
147 *
148 * Can be called without any locks held.
149 */
150void intel_frontbuffer_flip_prepare(struct drm_i915_private *dev_priv,
151 unsigned frontbuffer_bits)
152{
153 spin_lock(&dev_priv->fb_tracking.lock);
154 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits;
155 /* Remove stale busy bits due to the old buffer. */
156 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
157 spin_unlock(&dev_priv->fb_tracking.lock);
158}
159
160/**
161 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip
162 * @dev_priv: i915 device
163 * @frontbuffer_bits: frontbuffer plane tracking bits
164 *
165 * This function gets called after the flip has been latched and will complete
166 * on the next vblank. It will execute the flush if it hasn't been cancelled yet.
167 *
168 * Can be called without any locks held.
169 */
170void intel_frontbuffer_flip_complete(struct drm_i915_private *dev_priv,
171 unsigned frontbuffer_bits)
172{
173 spin_lock(&dev_priv->fb_tracking.lock);
174 /* Mask any cancelled flips. */
175 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits;
176 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
177 spin_unlock(&dev_priv->fb_tracking.lock);
178
179 if (frontbuffer_bits)
180 intel_frontbuffer_flush(dev_priv,
181 frontbuffer_bits, ORIGIN_FLIP);
182}
183
184/**
185 * intel_frontbuffer_flip - synchronous frontbuffer flip
186 * @dev_priv: i915 device
187 * @frontbuffer_bits: frontbuffer plane tracking bits
188 *
189 * This function gets called after scheduling a flip on @obj. This is for
190 * synchronous plane updates which will happen on the next vblank and which will
191 * not get delayed by pending gpu rendering.
192 *
193 * Can be called without any locks held.
194 */
195void intel_frontbuffer_flip(struct drm_i915_private *dev_priv,
196 unsigned frontbuffer_bits)
197{
198 spin_lock(&dev_priv->fb_tracking.lock);
199 /* Remove stale busy bits due to the old buffer. */
200 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
201 spin_unlock(&dev_priv->fb_tracking.lock);
202
203 intel_frontbuffer_flush(dev_priv, frontbuffer_bits, ORIGIN_FLIP);
204}