LXR linux/drivers/gpu/drm/i915/intel

   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 "intel_frontbuffer.h"
  67#include "i915_drv.h"
  68
  69void __intel_fb_obj_invalidate(struct drm_i915_gem_object *obj,
  70                               enum fb_op_origin origin,
  71                               unsigned int frontbuffer_bits)
  72{
  73        struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
  74
  75        if (origin == ORIGIN_CS) {
  76                spin_lock(&dev_priv->fb_tracking.lock);
  77                dev_priv->fb_tracking.busy_bits |= frontbuffer_bits;
  78                dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
  79                spin_unlock(&dev_priv->fb_tracking.lock);
  80        }
  81
  82        intel_psr_invalidate(dev_priv, frontbuffer_bits);
  83        intel_edp_drrs_invalidate(dev_priv, frontbuffer_bits);
  84        intel_fbc_invalidate(dev_priv, frontbuffer_bits, origin);
  85}
  86
  87/**
  88 * intel_frontbuffer_flush - flush frontbuffer
  89 * @dev_priv: i915 device
  90 * @frontbuffer_bits: frontbuffer plane tracking bits
  91 * @origin: which operation caused the flush
  92 *
  93 * This function gets called every time rendering on the given planes has
  94 * completed and frontbuffer caching can be started again. Flushes will get
  95 * delayed if they're blocked by some outstanding asynchronous rendering.
  96 *
  97 * Can be called without any locks held.
  98 */
  99static void intel_frontbuffer_flush(struct drm_i915_private *dev_priv,
 100                                    unsigned frontbuffer_bits,
 101                                    enum fb_op_origin origin)
 102{
 103        /* Delay flushing when rings are still busy.*/
 104        spin_lock(&dev_priv->fb_tracking.lock);
 105        frontbuffer_bits &= ~dev_priv->fb_tracking.busy_bits;
 106        spin_unlock(&dev_priv->fb_tracking.lock);
 107
 108        if (!frontbuffer_bits)
 109                return;
 110
 111        intel_edp_drrs_flush(dev_priv, frontbuffer_bits);
 112        intel_psr_flush(dev_priv, frontbuffer_bits, origin);
 113        intel_fbc_flush(dev_priv, frontbuffer_bits, origin);
 114}
 115
 116void __intel_fb_obj_flush(struct drm_i915_gem_object *obj,
 117                          enum fb_op_origin origin,
 118                          unsigned int frontbuffer_bits)
 119{
 120        struct drm_i915_private *dev_priv = to_i915(obj->base.dev);
 121
 122        if (origin == ORIGIN_CS) {
 123                spin_lock(&dev_priv->fb_tracking.lock);
 124                /* Filter out new bits since rendering started. */
 125                frontbuffer_bits &= dev_priv->fb_tracking.busy_bits;
 126                dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
 127                spin_unlock(&dev_priv->fb_tracking.lock);
 128        }
 129
 130        if (frontbuffer_bits)
 131                intel_frontbuffer_flush(dev_priv, frontbuffer_bits, origin);
 132}
 133
 134/**
 135 * intel_frontbuffer_flip_prepare - prepare asynchronous frontbuffer flip
 136 * @dev_priv: i915 device
 137 * @frontbuffer_bits: frontbuffer plane tracking bits
 138 *
 139 * This function gets called after scheduling a flip on @obj. The actual
 140 * frontbuffer flushing will be delayed until completion is signalled with
 141 * intel_frontbuffer_flip_complete. If an invalidate happens in between this
 142 * flush will be cancelled.
 143 *
 144 * Can be called without any locks held.
 145 */
 146void intel_frontbuffer_flip_prepare(struct drm_i915_private *dev_priv,
 147                                    unsigned frontbuffer_bits)
 148{
 149        spin_lock(&dev_priv->fb_tracking.lock);
 150        dev_priv->fb_tracking.flip_bits |= frontbuffer_bits;
 151        /* Remove stale busy bits due to the old buffer. */
 152        dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
 153        spin_unlock(&dev_priv->fb_tracking.lock);
 154
 155        intel_psr_single_frame_update(dev_priv, frontbuffer_bits);
 156}
 157
 158/**
 159 * intel_frontbuffer_flip_complete - complete asynchronous frontbuffer flip
 160 * @dev_priv: i915 device
 161 * @frontbuffer_bits: frontbuffer plane tracking bits
 162 *
 163 * This function gets called after the flip has been latched and will complete
 164 * on the next vblank. It will execute the flush if it hasn't been cancelled yet.
 165 *
 166 * Can be called without any locks held.
 167 */
 168void intel_frontbuffer_flip_complete(struct drm_i915_private *dev_priv,
 169                                     unsigned frontbuffer_bits)
 170{
 171        spin_lock(&dev_priv->fb_tracking.lock);
 172        /* Mask any cancelled flips. */
 173        frontbuffer_bits &= dev_priv->fb_tracking.flip_bits;
 174        dev_priv->fb_tracking.flip_bits &= ~frontbuffer_bits;
 175        spin_unlock(&dev_priv->fb_tracking.lock);
 176
 177        if (frontbuffer_bits)
 178                intel_frontbuffer_flush(dev_priv,
 179                                        frontbuffer_bits, ORIGIN_FLIP);
 180}
 181
 182/**
 183 * intel_frontbuffer_flip - synchronous frontbuffer flip
 184 * @dev_priv: i915 device
 185 * @frontbuffer_bits: frontbuffer plane tracking bits
 186 *
 187 * This function gets called after scheduling a flip on @obj. This is for
 188 * synchronous plane updates which will happen on the next vblank and which will
 189 * not get delayed by pending gpu rendering.
 190 *
 191 * Can be called without any locks held.
 192 */
 193void intel_frontbuffer_flip(struct drm_i915_private *dev_priv,
 194                            unsigned frontbuffer_bits)
 195{
 196        spin_lock(&dev_priv->fb_tracking.lock);
 197        /* Remove stale busy bits due to the old buffer. */
 198        dev_priv->fb_tracking.busy_bits &= ~frontbuffer_bits;
 199        spin_unlock(&dev_priv->fb_tracking.lock);
 200
 201        intel_frontbuffer_flush(dev_priv, frontbuffer_bits, ORIGIN_FLIP);
 202}
 203