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
 33struct drm_i915_private;
 34
 35enum fb_op_origin {
 36	ORIGIN_GTT,
 37	ORIGIN_CPU,
 38	ORIGIN_CS,
 39	ORIGIN_FLIP,
 40	ORIGIN_DIRTYFB,
 41};
 42
 43struct 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
 51void intel_frontbuffer_flip_prepare(struct drm_i915_private *i915,
 52				    unsigned frontbuffer_bits);
 53void intel_frontbuffer_flip_complete(struct drm_i915_private *i915,
 54				     unsigned frontbuffer_bits);
 55void intel_frontbuffer_flip(struct drm_i915_private *i915,
 56			    unsigned frontbuffer_bits);
 57
 58void intel_frontbuffer_put(struct intel_frontbuffer *front);
 59
 60static 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
 87struct intel_frontbuffer *
 88intel_frontbuffer_get(struct drm_i915_gem_object *obj);
 89
 90void __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 */
105static 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
121void __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 */
133static 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
148void intel_frontbuffer_track(struct intel_frontbuffer *old,
149			     struct intel_frontbuffer *new,
150			     unsigned int frontbuffer_bits);
151
152#endif /* __INTEL_FRONTBUFFER_H__ */