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 struct list_head *dups) 98 { 99 struct ttm_bo_global *glob; 100 struct ttm_validate_buffer *entry; 101 int ret; 102 103 if (list_empty(list)) 104 return 0; 105 106 entry = list_first_entry(list, struct ttm_validate_buffer, head); 107 glob = entry->bo->glob; 108 109 if (ticket) 110 ww_acquire_init(ticket, &reservation_ww_class); 111 112 list_for_each_entry(entry, list, head) { 113 struct ttm_buffer_object *bo = entry->bo; 114 115 ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket); 116 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { 117 __ttm_bo_unreserve(bo); 118 119 ret = -EBUSY; 120 121 } else if (ret == -EALREADY && dups) { 122 struct ttm_validate_buffer *safe = entry; 123 entry = list_prev_entry(entry, head); 124 list_del(&safe->head); 125 list_add(&safe->head, dups); 126 continue; 127 } 128 129 if (!ret) { 130 if (!entry->shared) 131 continue; 132 133 ret = reservation_object_reserve_shared(bo->resv); 134 if (!ret) 135 continue; 136 } 137 138 /* uh oh, we lost out, drop every reservation and try 139 * to only reserve this buffer, then start over if 140 * this succeeds. 141 */ 142 ttm_eu_backoff_reservation_reverse(list, entry); 143 144 if (ret == -EDEADLK && intr) { 145 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, 146 ticket); 147 } else if (ret == -EDEADLK) { 148 ww_mutex_lock_slow(&bo->resv->lock, ticket); 149 ret = 0; 150 } 151 152 if (!ret && entry->shared) 153 ret = reservation_object_reserve_shared(bo->resv); 154 155 if (unlikely(ret != 0)) { 156 if (ret == -EINTR) 157 ret = -ERESTARTSYS; 158 if (ticket) { 159 ww_acquire_done(ticket); 160 ww_acquire_fini(ticket); 161 } 162 return ret; 163 } 164 165 /* move this item to the front of the list, 166 * forces correct iteration of the loop without keeping track 167 */ 168 list_del(&entry->head); 169 list_add(&entry->head, list); 170 } 171 172 if (ticket) 173 ww_acquire_done(ticket); 174 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 175 ttm_eu_del_from_lru_locked(list); 176 lockmgr(&glob->lru_lock, LK_RELEASE); 177 return 0; 178 } 179 EXPORT_SYMBOL(ttm_eu_reserve_buffers); 180 181 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, 182 struct list_head *list, struct fence *fence) 183 { 184 struct ttm_validate_buffer *entry; 185 struct ttm_buffer_object *bo; 186 struct ttm_bo_global *glob; 187 struct ttm_bo_device *bdev; 188 struct ttm_bo_driver *driver; 189 190 if (list_empty(list)) 191 return; 192 193 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; 194 bdev = bo->bdev; 195 driver = bdev->driver; 196 glob = bo->glob; 197 198 lockmgr(&glob->lru_lock, LK_EXCLUSIVE); 199 200 list_for_each_entry(entry, list, head) { 201 bo = entry->bo; 202 if (entry->shared) 203 reservation_object_add_shared_fence(bo->resv, fence); 204 else 205 reservation_object_add_excl_fence(bo->resv, fence); 206 ttm_bo_add_to_lru(bo); 207 __ttm_bo_unreserve(bo); 208 } 209 lockmgr(&glob->lru_lock, LK_RELEASE); 210 if (ticket) 211 ww_acquire_fini(ticket); 212 } 213 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects); 214