cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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intel_frontbuffer.h (4452B)

      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_types.h"
     32
     33struct drm_i915_private;
     34
     35enum fb_op_origin {
     36	ORIGIN_CPU = 0,
     37	ORIGIN_CS,
     38	ORIGIN_FLIP,
     39	ORIGIN_DIRTYFB,
     40	ORIGIN_CURSOR_UPDATE,
     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__ */