xref: /freebsd/sys/dev/drm2/ttm/ttm_execbuf_util.h (revision 2a63c3be158216222d89a073dcbd6a72ee4aab5a)
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 <dev/drm2/ttm/ttm_bo_api.h>
35 
36 /**
37  * struct ttm_validate_buffer
38  *
39  * @head:           list head for thread-private list.
40  * @bo:             refcounted buffer object pointer.
41  * @reserved:       Indicates whether @bo has been reserved for validation.
42  * @removed:        Indicates whether @bo has been removed from lru lists.
43  * @put_count:      Number of outstanding references on bo::list_kref.
44  * @old_sync_obj:   Pointer to a sync object about to be unreferenced
45  */
46 
47 struct ttm_validate_buffer {
48 	struct list_head head;
49 	struct ttm_buffer_object *bo;
50 	bool reserved;
51 	bool removed;
52 	int put_count;
53 	void *old_sync_obj;
54 };
55 
56 /**
57  * function ttm_eu_backoff_reservation
58  *
59  * @list:     thread private list of ttm_validate_buffer structs.
60  *
61  * Undoes all buffer validation reservations for bos pointed to by
62  * the list entries.
63  */
64 
65 extern void ttm_eu_backoff_reservation(struct list_head *list);
66 
67 /**
68  * function ttm_eu_reserve_buffers
69  *
70  * @list:    thread private list of ttm_validate_buffer structs.
71  *
72  * Tries to reserve bos pointed to by the list entries for validation.
73  * If the function returns 0, all buffers are marked as "unfenced",
74  * taken off the lru lists and are not synced for write CPU usage.
75  *
76  * If the function detects a deadlock due to multiple threads trying to
77  * reserve the same buffers in reverse order, all threads except one will
78  * back off and retry. This function may sleep while waiting for
79  * CPU write reservations to be cleared, and for other threads to
80  * unreserve their buffers.
81  *
82  * This function may return -ERESTART or -EAGAIN if the calling process
83  * receives a signal while waiting. In that case, no buffers on the list
84  * will be reserved upon return.
85  *
86  * Buffers reserved by this function should be unreserved by
87  * a call to either ttm_eu_backoff_reservation() or
88  * ttm_eu_fence_buffer_objects() when command submission is complete or
89  * has failed.
90  */
91 
92 extern int ttm_eu_reserve_buffers(struct list_head *list);
93 
94 /**
95  * function ttm_eu_fence_buffer_objects.
96  *
97  * @list:        thread private list of ttm_validate_buffer structs.
98  * @sync_obj:    The new sync object 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 list_head *list, void *sync_obj);
107 
108 #endif
109