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 <sys/cdefs.h> 29 #include <dev/drm2/drmP.h> 30 #include <dev/drm2/ttm/ttm_execbuf_util.h> 31 #include <dev/drm2/ttm/ttm_bo_driver.h> 32 #include <dev/drm2/ttm/ttm_placement.h> 33 34 static void ttm_eu_backoff_reservation_locked(struct list_head *list) 35 { 36 struct ttm_validate_buffer *entry; 37 38 list_for_each_entry(entry, list, head) { 39 struct ttm_buffer_object *bo = entry->bo; 40 if (!entry->reserved) 41 continue; 42 43 if (entry->removed) { 44 ttm_bo_add_to_lru(bo); 45 entry->removed = false; 46 47 } 48 entry->reserved = false; 49 atomic_set(&bo->reserved, 0); 50 wakeup(bo); 51 } 52 } 53 54 static void ttm_eu_del_from_lru_locked(struct list_head *list) 55 { 56 struct ttm_validate_buffer *entry; 57 58 list_for_each_entry(entry, list, head) { 59 struct ttm_buffer_object *bo = entry->bo; 60 if (!entry->reserved) 61 continue; 62 63 if (!entry->removed) { 64 entry->put_count = ttm_bo_del_from_lru(bo); 65 entry->removed = true; 66 } 67 } 68 } 69 70 static void ttm_eu_list_ref_sub(struct list_head *list) 71 { 72 struct ttm_validate_buffer *entry; 73 74 list_for_each_entry(entry, list, head) { 75 struct ttm_buffer_object *bo = entry->bo; 76 77 if (entry->put_count) { 78 ttm_bo_list_ref_sub(bo, entry->put_count, true); 79 entry->put_count = 0; 80 } 81 } 82 } 83 84 void ttm_eu_backoff_reservation(struct list_head *list) 85 { 86 struct ttm_validate_buffer *entry; 87 struct ttm_bo_global *glob; 88 89 if (list_empty(list)) 90 return; 91 92 entry = list_first_entry(list, struct ttm_validate_buffer, head); 93 glob = entry->bo->glob; 94 mtx_lock(&glob->lru_lock); 95 ttm_eu_backoff_reservation_locked(list); 96 mtx_unlock(&glob->lru_lock); 97 } 98 99 /* 100 * Reserve buffers for validation. 101 * 102 * If a buffer in the list is marked for CPU access, we back off and 103 * wait for that buffer to become free for GPU access. 104 * 105 * If a buffer is reserved for another validation, the validator with 106 * the highest validation sequence backs off and waits for that buffer 107 * to become unreserved. This prevents deadlocks when validating multiple 108 * buffers in different orders. 109 */ 110 111 int ttm_eu_reserve_buffers(struct list_head *list) 112 { 113 struct ttm_bo_global *glob; 114 struct ttm_validate_buffer *entry; 115 int ret; 116 uint32_t val_seq; 117 118 if (list_empty(list)) 119 return 0; 120 121 list_for_each_entry(entry, list, head) { 122 entry->reserved = false; 123 entry->put_count = 0; 124 entry->removed = false; 125 } 126 127 entry = list_first_entry(list, struct ttm_validate_buffer, head); 128 glob = entry->bo->glob; 129 130 mtx_lock(&glob->lru_lock); 131 val_seq = entry->bo->bdev->val_seq++; 132 133 retry_locked: 134 list_for_each_entry(entry, list, head) { 135 struct ttm_buffer_object *bo = entry->bo; 136 137 /* already slowpath reserved? */ 138 if (entry->reserved) 139 continue; 140 141 ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq); 142 switch (ret) { 143 case 0: 144 break; 145 case -EBUSY: 146 ttm_eu_del_from_lru_locked(list); 147 ret = ttm_bo_reserve_nolru(bo, true, false, 148 true, val_seq); 149 if (!ret) 150 break; 151 152 if (unlikely(ret != -EAGAIN)) 153 goto err; 154 155 /* fallthrough */ 156 case -EAGAIN: 157 ttm_eu_backoff_reservation_locked(list); 158 159 /* 160 * temporarily increase sequence number every retry, 161 * to prevent us from seeing our old reservation 162 * sequence when someone else reserved the buffer, 163 * but hasn't updated the seq_valid/seqno members yet. 164 */ 165 val_seq = entry->bo->bdev->val_seq++; 166 167 ttm_eu_list_ref_sub(list); 168 ret = ttm_bo_reserve_slowpath_nolru(bo, true, val_seq); 169 if (unlikely(ret != 0)) { 170 mtx_unlock(&glob->lru_lock); 171 return ret; 172 } 173 entry->reserved = true; 174 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) { 175 ret = -EBUSY; 176 goto err; 177 } 178 goto retry_locked; 179 default: 180 goto err; 181 } 182 183 entry->reserved = true; 184 if (unlikely(atomic_read(&bo->cpu_writers) > 0)) { 185 ret = -EBUSY; 186 goto err; 187 } 188 } 189 190 ttm_eu_del_from_lru_locked(list); 191 mtx_unlock(&glob->lru_lock); 192 ttm_eu_list_ref_sub(list); 193 194 return 0; 195 196 err: 197 ttm_eu_backoff_reservation_locked(list); 198 mtx_unlock(&glob->lru_lock); 199 ttm_eu_list_ref_sub(list); 200 return ret; 201 } 202 203 void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj) 204 { 205 struct ttm_validate_buffer *entry; 206 struct ttm_buffer_object *bo; 207 struct ttm_bo_global *glob; 208 struct ttm_bo_device *bdev; 209 struct ttm_bo_driver *driver; 210 211 if (list_empty(list)) 212 return; 213 214 bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo; 215 bdev = bo->bdev; 216 driver = bdev->driver; 217 glob = bo->glob; 218 219 mtx_lock(&glob->lru_lock); 220 mtx_lock(&bdev->fence_lock); 221 222 list_for_each_entry(entry, list, head) { 223 bo = entry->bo; 224 entry->old_sync_obj = bo->sync_obj; 225 bo->sync_obj = driver->sync_obj_ref(sync_obj); 226 ttm_bo_unreserve_locked(bo); 227 entry->reserved = false; 228 } 229 mtx_unlock(&bdev->fence_lock); 230 mtx_unlock(&glob->lru_lock); 231 232 list_for_each_entry(entry, list, head) { 233 if (entry->old_sync_obj) 234 driver->sync_obj_unref(&entry->old_sync_obj); 235 } 236 } 237