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 #include <drm/ttm/ttm_execbuf_util.h> 29 #include <drm/ttm/ttm_bo_driver.h> 30 #include <drm/ttm/ttm_placement.h> 31 #include <linux/wait.h> 32 #include <linux/sched.h> 33 #include <linux/module.h> 34 35 static void ttm_eu_backoff_reservation_reverse(struct list_head *list, 36 struct ttm_validate_buffer *entry) 37 { 38 list_for_each_entry_continue_reverse(entry, list, head) { 39 struct ttm_buffer_object *bo = entry->bo; 40 41 __ttm_bo_unreserve(bo); 42 } 43 } 44 45 static void ttm_eu_del_from_lru_locked(struct list_head *list) 46 { 47 struct ttm_validate_buffer *entry; 48 49 list_for_each_entry(entry, list, head) { 50 struct ttm_buffer_object *bo = entry->bo; 51 unsigned put_count = ttm_bo_del_from_lru(bo); 52 53 ttm_bo_list_ref_sub(bo, put_count, true); 54 } 55 } 56 57 void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket, 58 struct list_head *list) 59 { 60 struct ttm_validate_buffer *entry; 61 struct ttm_bo_global *glob; 62 63 if (list_empty(list)) 64 return; 65 66 entry = list_first_entry(list, struct ttm_validate_buffer, head); 67 glob = entry->bo->glob; 68 69 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 70 list_for_each_entry(entry, list, head) { 71 struct ttm_buffer_object *bo = entry->bo; 72 73 ttm_bo_add_to_lru(bo); 74 __ttm_bo_unreserve(bo); 75 } 76 lockmgr(&glob->lru_lock, LK_RELEASE); 77 78 if (ticket) 79 ww_acquire_fini(ticket); 80 } 81 EXPORT_SYMBOL(ttm_eu_backoff_reservation); 82 83 /* 84 * Reserve buffers for validation. 85 * 86 * If a buffer in the list is marked for CPU access, we back off and 87 * wait for that buffer to become free for GPU access. 88 * 89 * If a buffer is reserved for another validation, the validator with 90 * the highest validation sequence backs off and waits for that buffer 91 * to become unreserved. This prevents deadlocks when validating multiple 92 * buffers in different orders. 93 */ 94 95 int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket, 96 struct list_head *list, bool intr) 97 { 98 struct ttm_bo_global *glob; 99 struct ttm_validate_buffer *entry; 100 int ret; 101 102 if (list_empty(list)) 103 return 0; 104 105 entry = list_first_entry(list, struct ttm_validate_buffer, head); 106 glob = entry->bo->glob; 107 108 if (ticket) 109 ww_acquire_init(ticket, &reservation_ww_class); 110 111 list_for_each_entry(entry, list, head) { 112 struct ttm_buffer_object *bo = entry->bo; 113 114 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), true, 115 ticket); 116 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { 117 __ttm_bo_unreserve(bo); 118 119 ret = -EBUSY; 120 } 121 122 if (!ret) { 123 if (!entry->shared) 124 continue; 125 126 ret = reservation_object_reserve_shared(bo->resv); 127 if (!ret) 128 continue; 129 } 130 131 /* uh oh, we lost out, drop every reservation and try 132 * to only reserve this buffer, then start over if 133 * this succeeds. 134 */ 135 ttm_eu_backoff_reservation_reverse(list, entry); 136 137 if (ret == -EDEADLK && intr) { 138 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, 139 ticket); 140 } else if (ret == -EDEADLK) { 141 ww_mutex_lock_slow(&bo->resv->lock, ticket); 142 ret = 0; 143 } 144 145 if (!ret && entry->shared) 146 ret = reservation_object_reserve_shared(bo->resv); 147 148 if (unlikely(ret != 0)) { 149 if (ret == -EINTR) 150 ret = -ERESTARTSYS; 151 if (ticket) { 152 ww_acquire_done(ticket); 153 ww_acquire_fini(ticket); 154 } 155 return ret; 156 } 157 158 /* move this item to the front of the list, 159 * forces correct iteration of the loop without keeping track 160 */ 161 list_del(&entry->head); 162 list_add(&entry->head, list); 163 } 164 165 if (ticket) 166 ww_acquire_done(ticket); 167 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 168 ttm_eu_del_from_lru_locked(list); 169 lockmgr(&glob->lru_lock, LK_RELEASE); 170 return 0; 171 } 172 EXPORT_SYMBOL(ttm_eu_reserve_buffers); 173 174 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, 175 struct list_head *list, struct fence *fence) 176 { 177 struct ttm_validate_buffer *entry; 178 struct ttm_buffer_object *bo; 179 struct ttm_bo_global *glob; 180 struct ttm_bo_device *bdev; 181 struct ttm_bo_driver *driver; 182 183 if (list_empty(list)) 184 return; 185 186 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; 187 bdev = bo->bdev; 188 driver = bdev->driver; 189 glob = bo->glob; 190 191 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 192 193 list_for_each_entry(entry, list, head) { 194 bo = entry->bo; 195 if (entry->shared) 196 reservation_object_add_shared_fence(bo->resv, fence); 197 else 198 reservation_object_add_excl_fence(bo->resv, fence); 199 ttm_bo_add_to_lru(bo); 200 __ttm_bo_unreserve(bo); 201 } 202 lockmgr(&glob->lru_lock, LK_RELEASE); 203 if (ticket) 204 ww_acquire_fini(ticket); 205 } 206 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects); 207