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 spin_lock(&glob->lru_lock); 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 spin_unlock(&glob->lru_lock); 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), true, 116 ticket); 117 if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) { 118 __ttm_bo_unreserve(bo); 119 120 ret = -EBUSY; 121 122 } else if (ret == -EALREADY && dups) { 123 struct ttm_validate_buffer *safe = entry; 124 entry = list_prev_entry(entry, head); 125 list_del(&safe->head); 126 list_add(&safe->head, dups); 127 continue; 128 } 129 130 if (!ret) { 131 if (!entry->shared) 132 continue; 133 134 ret = reservation_object_reserve_shared(bo->resv); 135 if (!ret) 136 continue; 137 } 138 139 /* uh oh, we lost out, drop every reservation and try 140 * to only reserve this buffer, then start over if 141 * this succeeds. 142 */ 143 ttm_eu_backoff_reservation_reverse(list, entry); 144 145 if (ret == -EDEADLK && intr) { 146 ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock, 147 ticket); 148 } else if (ret == -EDEADLK) { 149 ww_mutex_lock_slow(&bo->resv->lock, ticket); 150 ret = 0; 151 } 152 153 if (!ret && entry->shared) 154 ret = reservation_object_reserve_shared(bo->resv); 155 156 if (unlikely(ret != 0)) { 157 if (ret == -EINTR) 158 ret = -ERESTARTSYS; 159 if (ticket) { 160 ww_acquire_done(ticket); 161 ww_acquire_fini(ticket); 162 } 163 return ret; 164 } 165 166 /* move this item to the front of the list, 167 * forces correct iteration of the loop without keeping track 168 */ 169 list_del(&entry->head); 170 list_add(&entry->head, list); 171 } 172 173 if (ticket) 174 ww_acquire_done(ticket); 175 spin_lock(&glob->lru_lock); 176 ttm_eu_del_from_lru_locked(list); 177 spin_unlock(&glob->lru_lock); 178 return 0; 179 } 180 EXPORT_SYMBOL(ttm_eu_reserve_buffers); 181 182 void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket, 183 struct list_head *list, struct fence *fence) 184 { 185 struct ttm_validate_buffer *entry; 186 struct ttm_buffer_object *bo; 187 struct ttm_bo_global *glob; 188 struct ttm_bo_device *bdev; 189 struct ttm_bo_driver *driver; 190 191 if (list_empty(list)) 192 return; 193 194 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; 195 bdev = bo->bdev; 196 driver = bdev->driver; 197 glob = bo->glob; 198 199 spin_lock(&glob->lru_lock); 200 201 list_for_each_entry(entry, list, head) { 202 bo = entry->bo; 203 if (entry->shared) 204 reservation_object_add_shared_fence(bo->resv, fence); 205 else 206 reservation_object_add_excl_fence(bo->resv, fence); 207 ttm_bo_add_to_lru(bo); 208 __ttm_bo_unreserve(bo); 209 } 210 spin_unlock(&glob->lru_lock); 211 if (ticket) 212 ww_acquire_fini(ticket); 213 } 214 EXPORT_SYMBOL(ttm_eu_fence_buffer_objects); 215