Line data Source code
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 : #include <dev/pci/drm/drmP.h>
64 :
65 : #include "intel_drv.h"
66 : #include "i915_drv.h"
67 :
68 : /**
69 : * intel_fb_obj_invalidate - invalidate frontbuffer object
70 : * @obj: GEM object to invalidate
71 : * @origin: which operation caused the invalidation
72 : *
73 : * This function gets called every time rendering on the given object starts and
74 : * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must
75 : * be invalidated. For ORIGIN_CS any subsequent invalidation will be delayed
76 : * until the rendering completes or a flip on this frontbuffer plane is
77 : * scheduled.
78 : */
79 0 : void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
80 : enum fb_op_origin origin)
81 : {
82 0 : struct drm_device *dev = obj->base.dev;
83 0 : struct drm_i915_private *dev_priv = to_i915(dev);
84 :
85 0 : WARN_ON(!mutex_is_locked(&dev->struct_mutex));
86 :
87 0 : if (!obj->frontbuffer_bits)
88 0 : return;
89 :
90 0 : if (origin == ORIGIN_CS) {
91 0 : mutex_lock(&dev_priv->fb_tracking.lock);
92 0 : dev_priv->fb_tracking.busy_bits
93 0 : |= obj->frontbuffer_bits;
94 0 : dev_priv->fb_tracking.flip_bits
95 0 : &= ~obj->frontbuffer_bits;
96 0 : mutex_unlock(&dev_priv->fb_tracking.lock);
97 0 : }
98 :
99 0 : intel_psr_invalidate(dev, obj->frontbuffer_bits);
100 0 : intel_edp_drrs_invalidate(dev, obj->frontbuffer_bits);
101 0 : intel_fbc_invalidate(dev_priv, obj->frontbuffer_bits, origin);
102 0 : }
103 :
104 : /**
105 : * intel_frontbuffer_flush - flush frontbuffer
106 : * @dev: DRM device
107 : * @frontbuffer_bits: frontbuffer plane tracking bits
108 : * @origin: which operation caused the flush
109 : *
110 : * This function gets called every time rendering on the given planes has
111 : * completed and frontbuffer caching can be started again. Flushes will get
112 : * delayed if they're blocked by some outstanding asynchronous rendering.
113 : *
114 : * Can be called without any locks held.
115 : */
116 0 : static void intel_frontbuffer_flush(struct drm_device *dev,
117 : unsigned frontbuffer_bits,
118 : enum fb_op_origin origin)
119 : {
120 0 : struct drm_i915_private *dev_priv = to_i915(dev);
121 :
122 : /* Delay flushing when rings are still busy.*/
123 0 : mutex_lock(&dev_priv->fb_tracking.lock);
124 0 : frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits;
125 0 : mutex_unlock(&dev_priv->fb_tracking.lock);
126 :
127 0 : if (!frontbuffer_bits)
128 0 : return;
129 :
130 0 : intel_edp_drrs_flush(dev, frontbuffer_bits);
131 0 : intel_psr_flush(dev, frontbuffer_bits, origin);
132 0 : intel_fbc_flush(dev_priv, frontbuffer_bits, origin);
133 0 : }
134 :
135 : /**
136 : * intel_fb_obj_flush - flush frontbuffer object
137 : * @obj: GEM object to flush
138 : * @retire: set when retiring asynchronous rendering
139 : * @origin: which operation caused the flush
140 : *
141 : * This function gets called every time rendering on the given object has
142 : * completed and frontbuffer caching can be started again. If @retire is true
143 : * then any delayed flushes will be unblocked.
144 : */
145 0 : void intel_fb_obj_flush(struct drm_i915_gem_object *obj,
146 : bool retire, enum fb_op_origin origin)
147 : {
148 0 : struct drm_device *dev = obj->base.dev;
149 0 : struct drm_i915_private *dev_priv = to_i915(dev);
150 : unsigned frontbuffer_bits;
151 :
152 0 : WARN_ON(!mutex_is_locked(&dev->struct_mutex));
153 :
154 0 : if (!obj->frontbuffer_bits)
155 0 : return;
156 :
157 : frontbuffer_bits = obj->frontbuffer_bits;
158 :
159 0 : if (retire) {
160 0 : mutex_lock(&dev_priv->fb_tracking.lock);
161 : /* Filter out new bits since rendering started. */
162 0 : frontbuffer_bits &= dev_priv->fb_tracking.busy_bits;
163 :
164 0 : dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
165 0 : mutex_unlock(&dev_priv->fb_tracking.lock);
166 0 : }
167 :
168 0 : intel_frontbuffer_flush(dev, frontbuffer_bits, origin);
169 0 : }
170 :
171 : /**
172 : * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip
173 : * @dev: DRM device
174 : * @frontbuffer_bits: frontbuffer plane tracking bits
175 : *
176 : * This function gets called after scheduling a flip on @obj. The actual
177 : * frontbuffer flushing will be delayed until completion is signalled with
178 : * intel_frontbuffer_flip_complete. If an invalidate happens in between this
179 : * flush will be cancelled.
180 : *
181 : * Can be called without any locks held.
182 : */
183 0 : void intel_frontbuffer_flip_prepare(struct drm_device *dev,
184 : unsigned frontbuffer_bits)
185 : {
186 0 : struct drm_i915_private *dev_priv = to_i915(dev);
187 :
188 0 : mutex_lock(&dev_priv->fb_tracking.lock);
189 0 : dev_priv->fb_tracking.flip_bits |= frontbuffer_bits;
190 : /* Remove stale busy bits due to the old buffer. */
191 0 : dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
192 0 : mutex_unlock(&dev_priv->fb_tracking.lock);
193 :
194 0 : intel_psr_single_frame_update(dev, frontbuffer_bits);
195 0 : }
196 :
197 : /**
198 : * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip
199 : * @dev: DRM device
200 : * @frontbuffer_bits: frontbuffer plane tracking bits
201 : *
202 : * This function gets called after the flip has been latched and will complete
203 : * on the next vblank. It will execute the flush if it hasn't been cancelled yet.
204 : *
205 : * Can be called without any locks held.
206 : */
207 0 : void intel_frontbuffer_flip_complete(struct drm_device *dev,
208 : unsigned frontbuffer_bits)
209 : {
210 0 : struct drm_i915_private *dev_priv = to_i915(dev);
211 :
212 0 : mutex_lock(&dev_priv->fb_tracking.lock);
213 : /* Mask any cancelled flips. */
214 0 : frontbuffer_bits &= dev_priv->fb_tracking.flip_bits;
215 0 : dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
216 0 : mutex_unlock(&dev_priv->fb_tracking.lock);
217 :
218 0 : intel_frontbuffer_flush(dev, frontbuffer_bits, ORIGIN_FLIP);
219 0 : }
220 :
221 : /**
222 : * intel_frontbuffer_flip - synchronous frontbuffer flip
223 : * @dev: DRM device
224 : * @frontbuffer_bits: frontbuffer plane tracking bits
225 : *
226 : * This function gets called after scheduling a flip on @obj. This is for
227 : * synchronous plane updates which will happen on the next vblank and which will
228 : * not get delayed by pending gpu rendering.
229 : *
230 : * Can be called without any locks held.
231 : */
232 0 : void intel_frontbuffer_flip(struct drm_device *dev,
233 : unsigned frontbuffer_bits)
234 : {
235 0 : struct drm_i915_private *dev_priv = to_i915(dev);
236 :
237 0 : mutex_lock(&dev_priv->fb_tracking.lock);
238 : /* Remove stale busy bits due to the old buffer. */
239 0 : dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
240 0 : mutex_unlock(&dev_priv->fb_tracking.lock);
241 :
242 0 : intel_frontbuffer_flush(dev, frontbuffer_bits, ORIGIN_FLIP);
243 0 : }
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