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  2 *
  3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
  4 * All Rights Reserved.
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  6 * Permission is hereby granted, free of charge, to any person obtaining a
  7 * copy of this software and associated documentation files (the
  8 * "Software"), to deal in the Software without restriction, including
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 10 * distribute, sub license, and/or sell copies of the Software, and to
 11 * permit persons to whom the Software is furnished to do so, subject to
 12 * the following conditions:
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 14 * The above copyright notice and this permission notice (including the
 15 * next paragraph) shall be included in all copies or substantial portions
 16 * of the Software.
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 26 **************************************************************************/
 27/*
 28 * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
 29 */
 30
 31#ifndef _TTM_EXECBUF_UTIL_H_
 32#define _TTM_EXECBUF_UTIL_H_
 33
 34#include <linux/list.h>
 35
 36struct ww_acquire_ctx;
 37struct dma_fence;
 38struct ttm_buffer_object;
 39
 40/**
 41 * struct ttm_validate_buffer
 42 *
 43 * @head:           list head for thread-private list.
 44 * @bo:             refcounted buffer object pointer.
 45 * @num_shared:     How many shared fences we want to add.
 46 */
 47
 48struct ttm_validate_buffer {
 49	struct list_head head;
 50	struct ttm_buffer_object *bo;
 51	unsigned int num_shared;
 52};
 53
 54/**
 55 * function ttm_eu_backoff_reservation
 56 *
 57 * @ticket:   ww_acquire_ctx from reserve call
 58 * @list:     thread private list of ttm_validate_buffer structs.
 59 *
 60 * Undoes all buffer validation reservations for bos pointed to by
 61 * the list entries.
 62 */
 63void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
 64				struct list_head *list);
 65
 66/**
 67 * function ttm_eu_reserve_buffers
 68 *
 69 * @ticket:  [out] ww_acquire_ctx filled in by call, or NULL if only
 70 *           non-blocking reserves should be tried.
 71 * @list:    thread private list of ttm_validate_buffer structs.
 72 * @intr:    should the wait be interruptible
 73 * @dups:    [out] optional list of duplicates.
 74 * @del_lru: true if BOs should be removed from the LRU.
 75 *
 76 * Tries to reserve bos pointed to by the list entries for validation.
 77 * If the function returns 0, all buffers are marked as "unfenced",
 78 * taken off the lru lists and are not synced for write CPU usage.
 79 *
 80 * If the function detects a deadlock due to multiple threads trying to
 81 * reserve the same buffers in reverse order, all threads except one will
 82 * back off and retry. This function may sleep while waiting for
 83 * CPU write reservations to be cleared, and for other threads to
 84 * unreserve their buffers.
 85 *
 86 * If intr is set to true, this function may return -ERESTARTSYS if the
 87 * calling process receives a signal while waiting. In that case, no
 88 * buffers on the list will be reserved upon return.
 89 *
 90 * If dups is non NULL all buffers already reserved by the current thread
 91 * (e.g. duplicates) are added to this list, otherwise -EALREADY is returned
 92 * on the first already reserved buffer and all buffers from the list are
 93 * unreserved again.
 94 *
 95 * Buffers reserved by this function should be unreserved by
 96 * a call to either ttm_eu_backoff_reservation() or
 97 * ttm_eu_fence_buffer_objects() when command submission is complete or
 98 * has failed.
 99 */
100int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
101			   struct list_head *list, bool intr,
102			   struct list_head *dups);
103
104/**
105 * function ttm_eu_fence_buffer_objects.
106 *
107 * @ticket:      ww_acquire_ctx from reserve call
108 * @list:        thread private list of ttm_validate_buffer structs.
109 * @fence:       The new exclusive fence for the buffers.
110 *
111 * This function should be called when command submission is complete, and
112 * it will add a new sync object to bos pointed to by entries on @list.
113 * It also unreserves all buffers, putting them on lru lists.
114 *
115 */
116void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
117				 struct list_head *list,
118				 struct dma_fence *fence);
119
120#endif