drivers/gpu/drm/i915/display/intel_frontbuffer.h

   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/kref.h>
  29
  30 #include "gem/i915_gem_object_types.h"
  31 #include "i915_active.h"
  32
  33 struct drm_i915_private;
  34
  35 enum fb_op_origin {
  36         ORIGIN_GTT,
  37         ORIGIN_CPU,
  38         ORIGIN_CS,
  39         ORIGIN_FLIP,
  40         ORIGIN_DIRTYFB,
  41 };
  42
  43 struct intel_frontbuffer {
  44         struct kref ref;
  45         atomic_t bits;
  46         struct i915_active write;
  47         struct drm_i915_gem_object *obj;
  48         struct rcu_head rcu;
  49 };
  50
  51 void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
  52                                     unsigned frontbuffer_bits);
  53 void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
  54                                      unsigned frontbuffer_bits);
  55 void intel_frontbuffer_flip(struct drm_i915_private *i915,
  56                             unsigned frontbuffer_bits);
  57
  58 void intel_frontbuffer_put(struct intel_frontbuffer *front);
  59
  60 static inline struct intel_frontbuffer *
  61 __intel_frontbuffer_get(const struct drm_i915_gem_object *obj)
  62 {
  63         struct intel_frontbuffer *front;
  64
  65         if (likely(!rcu_access_pointer(obj->frontbuffer)))
  66                 return NULL;
  67
  68         rcu_read_lock();
  69         do {
  70                 front = rcu_dereference(obj->frontbuffer);
  71                 if (!front)
  72                         break;
  73
  74                 if (unlikely(!kref_get_unless_zero(&front->ref)))
  75                         continue;
  76
  77                 if (likely(front == rcu_access_pointer(obj->frontbuffer)))
  78                         break;
  79
  80                 intel_frontbuffer_put(front);
  81         } while (1);
  82         rcu_read_unlock();
  83
  84         return front;
  85 }
  86
  87 struct intel_frontbuffer *
  88 intel_frontbuffer_get(struct drm_i915_gem_object *obj);
  89
  90 void __intel_fb_invalidate(struct intel_frontbuffer *front,
  91                            enum fb_op_origin origin,
  92                            unsigned int frontbuffer_bits);
  93
  94 /**
  95  * intel_frontbuffer_invalidate - invalidate frontbuffer object
  96  * @front: GEM object to invalidate
  97  * @origin: which operation caused the invalidation
  98  *
  99  * This function gets called every time rendering on the given object starts and
 100  * frontbuffer caching (fbc, low refresh rate for DRRS, panel self refresh) must
 101  * be invalidated. For ORIGIN_CS any subsequent invalidation will be delayed
 102  * until the rendering completes or a flip on this frontbuffer plane is
 103  * scheduled.
 104  */
 105 static inline bool intel_frontbuffer_invalidate(struct intel_frontbuffer *front,
 106                                                 enum fb_op_origin origin)
 107 {
 108         unsigned int frontbuffer_bits;
 109
 110         if (!front)
 111                 return false;
 112
 113         frontbuffer_bits = atomic_read(&front->bits);
 114         if (!frontbuffer_bits)
 115                 return false;
 116
 117         __intel_fb_invalidate(front, origin, frontbuffer_bits);
 118         return true;
 119 }
 120
 121 void __intel_fb_flush(struct intel_frontbuffer *front,
 122                       enum fb_op_origin origin,
 123                       unsigned int frontbuffer_bits);
 124
 125 /**
 126  * intel_frontbuffer_flush - flush frontbuffer object
 127  * @front: GEM object to flush
 128  * @origin: which operation caused the flush
 129  *
 130  * This function gets called every time rendering on the given object has
 131  * completed and frontbuffer caching can be started again.
 132  */
 133 static inline void intel_frontbuffer_flush(struct intel_frontbuffer *front,
 134                                            enum fb_op_origin origin)
 135 {
 136         unsigned int frontbuffer_bits;
 137
 138         if (!front)
 139                 return;
 140
 141         frontbuffer_bits = atomic_read(&front->bits);
 142         if (!frontbuffer_bits)
 143                 return;
 144
 145         __intel_fb_flush(front, origin, frontbuffer_bits);
 146 }
 147
 148 void intel_frontbuffer_track(struct intel_frontbuffer *old,
 149                              struct intel_frontbuffer *new,
 150                              unsigned int frontbuffer_bits);
 151
 152 #endif /* __INTEL_FRONTBUFFER_H__ */