1 /**************************************************************************
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
9  * without limitation the rights to use, copy, modify, merge, publish,
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:
13  *
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.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
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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 
36 #include "ttm_bo_api.h"
37 
38 /**
39  * struct ttm_validate_buffer
40  *
41  * @head:           list head for thread-private list.
42  * @bo:             refcounted buffer object pointer.
43  * @num_shared:     How many shared fences we want to add.
44  */
45 
46 struct ttm_validate_buffer {
47 	struct list_head head;
48 	struct ttm_buffer_object *bo;
49 	unsigned int num_shared;
50 };
51 
52 /**
53  * function ttm_eu_backoff_reservation
54  *
55  * @ticket:   ww_acquire_ctx from reserve call
56  * @list:     thread private list of ttm_validate_buffer structs.
57  *
58  * Undoes all buffer validation reservations for bos pointed to by
59  * the list entries.
60  */
61 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
62 				struct list_head *list);
63 
64 /**
65  * function ttm_eu_reserve_buffers
66  *
67  * @ticket:  [out] ww_acquire_ctx filled in by call, or NULL if only
68  *           non-blocking reserves should be tried.
69  * @list:    thread private list of ttm_validate_buffer structs.
70  * @intr:    should the wait be interruptible
71  * @dups:    [out] optional list of duplicates.
72  * @del_lru: true if BOs should be removed from the LRU.
73  *
74  * Tries to reserve bos pointed to by the list entries for validation.
75  * If the function returns 0, all buffers are marked as "unfenced",
76  * taken off the lru lists and are not synced for write CPU usage.
77  *
78  * If the function detects a deadlock due to multiple threads trying to
79  * reserve the same buffers in reverse order, all threads except one will
80  * back off and retry. This function may sleep while waiting for
81  * CPU write reservations to be cleared, and for other threads to
82  * unreserve their buffers.
83  *
84  * If intr is set to true, this function may return -ERESTARTSYS if the
85  * calling process receives a signal while waiting. In that case, no
86  * buffers on the list will be reserved upon return.
87  *
88  * If dups is non NULL all buffers already reserved by the current thread
89  * (e.g. duplicates) are added to this list, otherwise -EALREADY is returned
90  * on the first already reserved buffer and all buffers from the list are
91  * unreserved again.
92  *
93  * Buffers reserved by this function should be unreserved by
94  * a call to either ttm_eu_backoff_reservation() or
95  * ttm_eu_fence_buffer_objects() when command submission is complete or
96  * has failed.
97  */
98 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
99 			   struct list_head *list, bool intr,
100 			   struct list_head *dups);
101 
102 /**
103  * function ttm_eu_fence_buffer_objects.
104  *
105  * @ticket:      ww_acquire_ctx from reserve call
106  * @list:        thread private list of ttm_validate_buffer structs.
107  * @fence:       The new exclusive fence for the buffers.
108  *
109  * This function should be called when command submission is complete, and
110  * it will add a new sync object to bos pointed to by entries on @list.
111  * It also unreserves all buffers, putting them on lru lists.
112  *
113  */
114 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
115 				 struct list_head *list,
116 				 struct dma_fence *fence);
117 
118 #endif
119