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 <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 */
intel_fb_obj_invalidate(struct drm_i915_gem_object * obj,enum fb_op_origin origin)79 void intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
80 enum fb_op_origin origin)
81 {
82 struct drm_device *dev = obj->base.dev;
83 struct drm_i915_private *dev_priv = to_i915(dev);
84
85 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
86
87 if (!obj->frontbuffer_bits)
88 return;
89
90 if (origin == ORIGIN_CS) {
91 mutex_lock(&dev_priv->fb_tracking.lock);
92 dev_priv->fb_tracking.busy_bits
93 |= obj->frontbuffer_bits;
94 dev_priv->fb_tracking.flip_bits
95 &= ~obj->frontbuffer_bits;
96 mutex_unlock(&dev_priv->fb_tracking.lock);
97 }
98
99 intel_psr_invalidate(dev, obj->frontbuffer_bits);
100 intel_edp_drrs_invalidate(dev, obj->frontbuffer_bits);
101 intel_fbc_invalidate(dev_priv, obj->frontbuffer_bits, origin);
102 }
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 */
intel_frontbuffer_flush(struct drm_device * dev,unsigned frontbuffer_bits,enum fb_op_origin origin)116 static void intel_frontbuffer_flush(struct drm_device *dev,
117 unsigned frontbuffer_bits,
118 enum fb_op_origin origin)
119 {
120 struct drm_i915_private *dev_priv = to_i915(dev);
121
122 /* Delay flushing when rings are still busy.*/
123 mutex_lock(&dev_priv->fb_tracking.lock);
124 frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits;
125 mutex_unlock(&dev_priv->fb_tracking.lock);
126
127 if (!frontbuffer_bits)
128 return;
129
130 intel_edp_drrs_flush(dev, frontbuffer_bits);
131 intel_psr_flush(dev, frontbuffer_bits, origin);
132 intel_fbc_flush(dev_priv, frontbuffer_bits, origin);
133 }
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 */
intel_fb_obj_flush(struct drm_i915_gem_object * obj,bool retire,enum fb_op_origin origin)145 void intel_fb_obj_flush(struct drm_i915_gem_object *obj,
146 bool retire, enum fb_op_origin origin)
147 {
148 struct drm_device *dev = obj->base.dev;
149 struct drm_i915_private *dev_priv = to_i915(dev);
150 unsigned frontbuffer_bits;
151
152 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
153
154 if (!obj->frontbuffer_bits)
155 return;
156
157 frontbuffer_bits = obj->frontbuffer_bits;
158
159 if (retire) {
160 mutex_lock(&dev_priv->fb_tracking.lock);
161 /* Filter out new bits since rendering started. */
162 frontbuffer_bits &= dev_priv->fb_tracking.busy_bits;
163
164 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
165 mutex_unlock(&dev_priv->fb_tracking.lock);
166 }
167
168 intel_frontbuffer_flush(dev, frontbuffer_bits, origin);
169 }
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 */
intel_frontbuffer_flip_prepare(struct drm_device * dev,unsigned frontbuffer_bits)183 void intel_frontbuffer_flip_prepare(struct drm_device *dev,
184 unsigned frontbuffer_bits)
185 {
186 struct drm_i915_private *dev_priv = to_i915(dev);
187
188 mutex_lock(&dev_priv->fb_tracking.lock);
189 dev_priv->fb_tracking.flip_bits |= frontbuffer_bits;
190 /* Remove stale busy bits due to the old buffer. */
191 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
192 mutex_unlock(&dev_priv->fb_tracking.lock);
193
194 intel_psr_single_frame_update(dev, frontbuffer_bits);
195 }
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 */
intel_frontbuffer_flip_complete(struct drm_device * dev,unsigned frontbuffer_bits)207 void intel_frontbuffer_flip_complete(struct drm_device *dev,
208 unsigned frontbuffer_bits)
209 {
210 struct drm_i915_private *dev_priv = to_i915(dev);
211
212 mutex_lock(&dev_priv->fb_tracking.lock);
213 /* Mask any cancelled flips. */
214 frontbuffer_bits &= dev_priv->fb_tracking.flip_bits;
215 dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
216 mutex_unlock(&dev_priv->fb_tracking.lock);
217
218 intel_frontbuffer_flush(dev, frontbuffer_bits, ORIGIN_FLIP);
219 }
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 */
intel_frontbuffer_flip(struct drm_device * dev,unsigned frontbuffer_bits)232 void intel_frontbuffer_flip(struct drm_device *dev,
233 unsigned frontbuffer_bits)
234 {
235 struct drm_i915_private *dev_priv = to_i915(dev);
236
237 mutex_lock(&dev_priv->fb_tracking.lock);
238 /* Remove stale busy bits due to the old buffer. */
239 dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
240 mutex_unlock(&dev_priv->fb_tracking.lock);
241
242 intel_frontbuffer_flush(dev, frontbuffer_bits, ORIGIN_FLIP);
243 }
244