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2 *
3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
4 * All Rights Reserved.
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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
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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 struct ww_acquire_ctx;
37 struct dma_fence;
38 struct ttm_buffer_object;
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 * 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 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
64 struct list_head *list);
65
66 /**
67 * ttm_eu_reserve_buffers
68 *
69 * @ticket: [out] ww_acquire_ctx filled in by call, or NULL if only
70 * non-blocking reserves should be tried.
71 * @list: thread private list of ttm_validate_buffer structs.
72 * @intr: should the wait be interruptible
73 * @dups: [out] optional list of duplicates.
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 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
100 struct list_head *list, bool intr,
101 struct list_head *dups);
102
103 /**
104 * ttm_eu_fence_buffer_objects
105 *
106 * @ticket: ww_acquire_ctx from reserve call
107 * @list: thread private list of ttm_validate_buffer structs.
108 * @fence: The new exclusive fence for the buffers.
109 *
110 * This function should be called when command submission is complete, and
111 * it will add a new sync object to bos pointed to by entries on @list.
112 * It also unreserves all buffers, putting them on lru lists.
113 *
114 */
115 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
116 struct list_head *list,
117 struct dma_fence *fence);
118
119 #endif
120
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