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 <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 * @reserved: Indicates whether @bo has been reserved for validation. 43 * @removed: Indicates whether @bo has been removed from lru lists. 44 * @put_count: Number of outstanding references on bo::list_kref. 45 * @old_sync_obj: Pointer to a sync object about to be unreferenced 46 */ 47 48 struct ttm_validate_buffer { 49 struct list_head head; 50 struct ttm_buffer_object *bo; 51 bool reserved; 52 bool removed; 53 int put_count; 54 void *old_sync_obj; 55 }; 56 57 /** 58 * function ttm_eu_backoff_reservation 59 * 60 * @list: thread private list of ttm_validate_buffer structs. 61 * 62 * Undoes all buffer validation reservations for bos pointed to by 63 * the list entries. 64 */ 65 66 extern void ttm_eu_backoff_reservation(struct list_head *list); 67 68 /** 69 * function ttm_eu_reserve_buffers 70 * 71 * @list: thread private list of ttm_validate_buffer structs. 72 * 73 * Tries to reserve bos pointed to by the list entries for validation. 74 * If the function returns 0, all buffers are marked as "unfenced", 75 * taken off the lru lists and are not synced for write CPU usage. 76 * 77 * If the function detects a deadlock due to multiple threads trying to 78 * reserve the same buffers in reverse order, all threads except one will 79 * back off and retry. This function may sleep while waiting for 80 * CPU write reservations to be cleared, and for other threads to 81 * unreserve their buffers. 82 * 83 * This function may return -ERESTART or -EAGAIN if the calling process 84 * receives a signal while waiting. In that case, no buffers on the list 85 * will be reserved upon return. 86 * 87 * Buffers reserved by this function should be unreserved by 88 * a call to either ttm_eu_backoff_reservation() or 89 * ttm_eu_fence_buffer_objects() when command submission is complete or 90 * has failed. 91 */ 92 93 extern int ttm_eu_reserve_buffers(struct list_head *list); 94 95 /** 96 * function ttm_eu_fence_buffer_objects. 97 * 98 * @list: thread private list of ttm_validate_buffer structs. 99 * @sync_obj: The new sync object for the buffers. 100 * 101 * This function should be called when command submission is complete, and 102 * it will add a new sync object to bos pointed to by entries on @list. 103 * It also unreserves all buffers, putting them on lru lists. 104 * 105 */ 106 107 extern void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj); 108 109 #endif 110