1 /**************************************************************************
2  *
3  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4  * All Rights Reserved.
5  *
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
21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
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 
62 extern void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
63 				       struct list_head *list);
64 
65 /**
66  * function ttm_eu_reserve_buffers
67  *
68  * @ticket:  [out] ww_acquire_ctx filled in by call, or NULL if only
69  *           non-blocking reserves should be tried.
70  * @list:    thread private list of ttm_validate_buffer structs.
71  * @intr:    should the wait be interruptible
72  * @dups:    [out] optional list of duplicates.
73  * @del_lru: true if BOs should be removed from the LRU.
74  *
75  * Tries to reserve bos pointed to by the list entries for validation.
76  * If the function returns 0, all buffers are marked as "unfenced",
77  * taken off the lru lists and are not synced for write CPU usage.
78  *
79  * If the function detects a deadlock due to multiple threads trying to
80  * reserve the same buffers in reverse order, all threads except one will
81  * back off and retry. This function may sleep while waiting for
82  * CPU write reservations to be cleared, and for other threads to
83  * unreserve their buffers.
84  *
85  * If intr is set to true, this function may return -ERESTARTSYS if the
86  * calling process receives a signal while waiting. In that case, no
87  * buffers on the list will be reserved upon return.
88  *
89  * If dups is non NULL all buffers already reserved by the current thread
90  * (e.g. duplicates) are added to this list, otherwise -EALREADY is returned
91  * on the first already reserved buffer and all buffers from the list are
92  * unreserved again.
93  *
94  * Buffers reserved by this function should be unreserved by
95  * a call to either ttm_eu_backoff_reservation() or
96  * ttm_eu_fence_buffer_objects() when command submission is complete or
97  * has failed.
98  */
99 
100 extern int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
101 				  struct list_head *list, bool intr,
102 				  struct list_head *dups, bool del_lru);
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  */
116 
117 extern void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
118 					struct list_head *list,
119 					struct dma_fence *fence);
120 
121 #endif
122