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.
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19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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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 <ttm/ttm_bo_api.h>
35 #include <linux/list.h>
36 
37 /**
38  * struct ttm_validate_buffer
39  *
40  * @head:           list head for thread-private list.
41  * @bo:             refcounted buffer object pointer.
42  */
43 
44 struct ttm_validate_buffer {
45 	struct list_head head;
46 	struct ttm_buffer_object *bo;
47 };
48 
49 /**
50  * function ttm_eu_backoff_reservation
51  *
52  * @ticket:   ww_acquire_ctx from reserve call
53  * @list:     thread private list of ttm_validate_buffer structs.
54  *
55  * Undoes all buffer validation reservations for bos pointed to by
56  * the list entries.
57  */
58 
59 extern void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
60 				       struct list_head *list);
61 
62 /**
63  * function ttm_eu_reserve_buffers
64  *
65  * @ticket:  [out] ww_acquire_ctx filled in by call, or NULL if only
66  *           non-blocking reserves should be tried.
67  * @list:    thread private list of ttm_validate_buffer structs.
68  * @intr:    should the wait be interruptible
69  *
70  * Tries to reserve bos pointed to by the list entries for validation.
71  * If the function returns 0, all buffers are marked as "unfenced",
72  * taken off the lru lists and are not synced for write CPU usage.
73  *
74  * If the function detects a deadlock due to multiple threads trying to
75  * reserve the same buffers in reverse order, all threads except one will
76  * back off and retry. This function may sleep while waiting for
77  * CPU write reservations to be cleared, and for other threads to
78  * unreserve their buffers.
79  *
80  * If intr is set to true, this function may return -ERESTARTSYS if the
81  * calling process receives a signal while waiting. In that case, no
82  * buffers on the list will be reserved upon return.
83  *
84  * Buffers reserved by this function should be unreserved by
85  * a call to either ttm_eu_backoff_reservation() or
86  * ttm_eu_fence_buffer_objects() when command submission is complete or
87  * has failed.
88  */
89 
90 extern int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
91 				  struct list_head *list, bool intr);
92 
93 /**
94  * function ttm_eu_fence_buffer_objects.
95  *
96  * @ticket:      ww_acquire_ctx from reserve call
97  * @list:        thread private list of ttm_validate_buffer structs.
98  * @fence:       The new exclusive fence for the buffers.
99  *
100  * This function should be called when command submission is complete, and
101  * it will add a new sync object to bos pointed to by entries on @list.
102  * It also unreserves all buffers, putting them on lru lists.
103  *
104  */
105 
106 extern void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
107 					struct list_head *list,
108 					struct fence *fence);
109 
110 #endif
111