xref: /netbsd-src/sys/external/bsd/drm2/dist/include/drm/ttm/ttm_execbuf_util.h (revision 41ec02673d281bbb3d38e6c78504ce6e30c228c1)
1 /*	$NetBSD: ttm_execbuf_util.h,v 1.3 2021/12/18 23:45:46 riastradh Exp $	*/
2 
3 /**************************************************************************
4  *
5  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
6  * All Rights Reserved.
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a
9  * copy of this software and associated documentation files (the
10  * "Software"), to deal in the Software without restriction, including
11  * without limitation the rights to use, copy, modify, merge, publish,
12  * distribute, sub license, and/or sell copies of the Software, and to
13  * permit persons to whom the Software is furnished to do so, subject to
14  * the following conditions:
15  *
16  * The above copyright notice and this permission notice (including the
17  * next paragraph) shall be included in all copies or substantial portions
18  * of the Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
23  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
24  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
25  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
26  * USE OR OTHER DEALINGS IN THE SOFTWARE.
27  *
28  **************************************************************************/
29 /*
30  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
31  */
32 
33 #ifndef _TTM_EXECBUF_UTIL_H_
34 #define _TTM_EXECBUF_UTIL_H_
35 
36 #include <linux/list.h>
37 
38 #include "ttm_bo_api.h"
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 
48 struct 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  */
63 
64 extern void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
65 				       struct list_head *list);
66 
67 /**
68  * function ttm_eu_reserve_buffers
69  *
70  * @ticket:  [out] ww_acquire_ctx filled in by call, or NULL if only
71  *           non-blocking reserves should be tried.
72  * @list:    thread private list of ttm_validate_buffer structs.
73  * @intr:    should the wait be interruptible
74  * @dups:    [out] optional list of duplicates.
75  * @del_lru: true if BOs should be removed from the LRU.
76  *
77  * Tries to reserve bos pointed to by the list entries for validation.
78  * If the function returns 0, all buffers are marked as "unfenced",
79  * taken off the lru lists and are not synced for write CPU usage.
80  *
81  * If the function detects a deadlock due to multiple threads trying to
82  * reserve the same buffers in reverse order, all threads except one will
83  * back off and retry. This function may sleep while waiting for
84  * CPU write reservations to be cleared, and for other threads to
85  * unreserve their buffers.
86  *
87  * If intr is set to true, this function may return -ERESTARTSYS if the
88  * calling process receives a signal while waiting. In that case, no
89  * buffers on the list will be reserved upon return.
90  *
91  * If dups is non NULL all buffers already reserved by the current thread
92  * (e.g. duplicates) are added to this list, otherwise -EALREADY is returned
93  * on the first already reserved buffer and all buffers from the list are
94  * unreserved again.
95  *
96  * Buffers reserved by this function should be unreserved by
97  * a call to either ttm_eu_backoff_reservation() or
98  * ttm_eu_fence_buffer_objects() when command submission is complete or
99  * has failed.
100  */
101 
102 extern int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
103 				  struct list_head *list, bool intr,
104 				  struct list_head *dups);
105 
106 /**
107  * function ttm_eu_fence_buffer_objects.
108  *
109  * @ticket:      ww_acquire_ctx from reserve call
110  * @list:        thread private list of ttm_validate_buffer structs.
111  * @fence:       The new exclusive fence for the buffers.
112  *
113  * This function should be called when command submission is complete, and
114  * it will add a new sync object to bos pointed to by entries on @list.
115  * It also unreserves all buffers, putting them on lru lists.
116  *
117  */
118 
119 extern void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
120 					struct list_head *list,
121 					struct dma_fence *fence);
122 
123 #endif
124