1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2021 Intel Corporation 4 */ 5 6 #include "xe_sync.h" 7 8 #include <linux/dma-fence-array.h> 9 #include <linux/kthread.h> 10 #include <linux/sched/mm.h> 11 #include <linux/uaccess.h> 12 13 #include <drm/drm_print.h> 14 #include <drm/drm_syncobj.h> 15 #include <uapi/drm/xe_drm.h> 16 17 #include "xe_device_types.h" 18 #include "xe_exec_queue.h" 19 #include "xe_macros.h" 20 #include "xe_sched_job_types.h" 21 22 struct xe_user_fence { 23 struct xe_device *xe; 24 struct kref refcount; 25 struct dma_fence_cb cb; 26 struct work_struct worker; 27 struct mm_struct *mm; 28 u64 __user *addr; 29 u64 value; 30 int signalled; 31 }; 32 33 static void user_fence_destroy(struct kref *kref) 34 { 35 struct xe_user_fence *ufence = container_of(kref, struct xe_user_fence, 36 refcount); 37 38 mmdrop(ufence->mm); 39 kfree(ufence); 40 } 41 42 static void user_fence_get(struct xe_user_fence *ufence) 43 { 44 kref_get(&ufence->refcount); 45 } 46 47 static void user_fence_put(struct xe_user_fence *ufence) 48 { 49 kref_put(&ufence->refcount, user_fence_destroy); 50 } 51 52 static struct xe_user_fence *user_fence_create(struct xe_device *xe, u64 addr, 53 u64 value) 54 { 55 struct xe_user_fence *ufence; 56 u64 __user *ptr = u64_to_user_ptr(addr); 57 u64 __maybe_unused prefetch_val; 58 59 if (get_user(prefetch_val, ptr)) 60 return ERR_PTR(-EFAULT); 61 62 ufence = kzalloc(sizeof(*ufence), GFP_KERNEL); 63 if (!ufence) 64 return ERR_PTR(-ENOMEM); 65 66 ufence->xe = xe; 67 kref_init(&ufence->refcount); 68 ufence->addr = ptr; 69 ufence->value = value; 70 ufence->mm = current->mm; 71 mmgrab(ufence->mm); 72 73 return ufence; 74 } 75 76 static void user_fence_worker(struct work_struct *w) 77 { 78 struct xe_user_fence *ufence = container_of(w, struct xe_user_fence, worker); 79 80 if (mmget_not_zero(ufence->mm)) { 81 kthread_use_mm(ufence->mm); 82 if (copy_to_user(ufence->addr, &ufence->value, sizeof(ufence->value))) 83 XE_WARN_ON("Copy to user failed"); 84 kthread_unuse_mm(ufence->mm); 85 mmput(ufence->mm); 86 } else { 87 drm_dbg(&ufence->xe->drm, "mmget_not_zero() failed, ufence wasn't signaled\n"); 88 } 89 90 /* 91 * Wake up waiters only after updating the ufence state, allowing the UMD 92 * to safely reuse the same ufence without encountering -EBUSY errors. 93 */ 94 WRITE_ONCE(ufence->signalled, 1); 95 wake_up_all(&ufence->xe->ufence_wq); 96 user_fence_put(ufence); 97 } 98 99 static void kick_ufence(struct xe_user_fence *ufence, struct dma_fence *fence) 100 { 101 INIT_WORK(&ufence->worker, user_fence_worker); 102 queue_work(ufence->xe->ordered_wq, &ufence->worker); 103 dma_fence_put(fence); 104 } 105 106 static void user_fence_cb(struct dma_fence *fence, struct dma_fence_cb *cb) 107 { 108 struct xe_user_fence *ufence = container_of(cb, struct xe_user_fence, cb); 109 110 kick_ufence(ufence, fence); 111 } 112 113 int xe_sync_entry_parse(struct xe_device *xe, struct xe_file *xef, 114 struct xe_sync_entry *sync, 115 struct drm_xe_sync __user *sync_user, 116 unsigned int flags) 117 { 118 struct drm_xe_sync sync_in; 119 int err; 120 bool exec = flags & SYNC_PARSE_FLAG_EXEC; 121 bool in_lr_mode = flags & SYNC_PARSE_FLAG_LR_MODE; 122 bool disallow_user_fence = flags & SYNC_PARSE_FLAG_DISALLOW_USER_FENCE; 123 bool signal; 124 125 if (copy_from_user(&sync_in, sync_user, sizeof(*sync_user))) 126 return -EFAULT; 127 128 if (XE_IOCTL_DBG(xe, sync_in.flags & ~DRM_XE_SYNC_FLAG_SIGNAL) || 129 XE_IOCTL_DBG(xe, sync_in.reserved[0] || sync_in.reserved[1])) 130 return -EINVAL; 131 132 signal = sync_in.flags & DRM_XE_SYNC_FLAG_SIGNAL; 133 switch (sync_in.type) { 134 case DRM_XE_SYNC_TYPE_SYNCOBJ: 135 if (XE_IOCTL_DBG(xe, in_lr_mode && signal)) 136 return -EOPNOTSUPP; 137 138 if (XE_IOCTL_DBG(xe, upper_32_bits(sync_in.addr))) 139 return -EINVAL; 140 141 sync->syncobj = drm_syncobj_find(xef->drm, sync_in.handle); 142 if (XE_IOCTL_DBG(xe, !sync->syncobj)) 143 return -ENOENT; 144 145 if (!signal) { 146 sync->fence = drm_syncobj_fence_get(sync->syncobj); 147 if (XE_IOCTL_DBG(xe, !sync->fence)) 148 return -EINVAL; 149 } 150 break; 151 152 case DRM_XE_SYNC_TYPE_TIMELINE_SYNCOBJ: 153 if (XE_IOCTL_DBG(xe, in_lr_mode && signal)) 154 return -EOPNOTSUPP; 155 156 if (XE_IOCTL_DBG(xe, upper_32_bits(sync_in.addr))) 157 return -EINVAL; 158 159 if (XE_IOCTL_DBG(xe, sync_in.timeline_value == 0)) 160 return -EINVAL; 161 162 sync->syncobj = drm_syncobj_find(xef->drm, sync_in.handle); 163 if (XE_IOCTL_DBG(xe, !sync->syncobj)) 164 return -ENOENT; 165 166 if (signal) { 167 sync->chain_fence = dma_fence_chain_alloc(); 168 if (!sync->chain_fence) 169 return -ENOMEM; 170 } else { 171 sync->fence = drm_syncobj_fence_get(sync->syncobj); 172 if (XE_IOCTL_DBG(xe, !sync->fence)) 173 return -EINVAL; 174 175 err = dma_fence_chain_find_seqno(&sync->fence, 176 sync_in.timeline_value); 177 if (err) 178 return err; 179 } 180 break; 181 182 case DRM_XE_SYNC_TYPE_USER_FENCE: 183 if (XE_IOCTL_DBG(xe, disallow_user_fence)) 184 return -EOPNOTSUPP; 185 186 if (XE_IOCTL_DBG(xe, !signal)) 187 return -EOPNOTSUPP; 188 189 if (XE_IOCTL_DBG(xe, sync_in.addr & 0x7)) 190 return -EINVAL; 191 192 if (exec) { 193 sync->addr = sync_in.addr; 194 } else { 195 sync->ufence = user_fence_create(xe, sync_in.addr, 196 sync_in.timeline_value); 197 if (XE_IOCTL_DBG(xe, IS_ERR(sync->ufence))) 198 return PTR_ERR(sync->ufence); 199 } 200 201 break; 202 203 default: 204 return -EINVAL; 205 } 206 207 sync->type = sync_in.type; 208 sync->flags = sync_in.flags; 209 sync->timeline_value = sync_in.timeline_value; 210 211 return 0; 212 } 213 214 int xe_sync_entry_add_deps(struct xe_sync_entry *sync, struct xe_sched_job *job) 215 { 216 if (sync->fence) 217 return drm_sched_job_add_dependency(&job->drm, 218 dma_fence_get(sync->fence)); 219 220 return 0; 221 } 222 223 void xe_sync_entry_signal(struct xe_sync_entry *sync, struct dma_fence *fence) 224 { 225 if (!(sync->flags & DRM_XE_SYNC_FLAG_SIGNAL)) 226 return; 227 228 if (sync->chain_fence) { 229 drm_syncobj_add_point(sync->syncobj, sync->chain_fence, 230 fence, sync->timeline_value); 231 /* 232 * The chain's ownership is transferred to the 233 * timeline. 234 */ 235 sync->chain_fence = NULL; 236 } else if (sync->syncobj) { 237 drm_syncobj_replace_fence(sync->syncobj, fence); 238 } else if (sync->ufence) { 239 int err; 240 241 dma_fence_get(fence); 242 user_fence_get(sync->ufence); 243 err = dma_fence_add_callback(fence, &sync->ufence->cb, 244 user_fence_cb); 245 if (err == -ENOENT) { 246 kick_ufence(sync->ufence, fence); 247 } else if (err) { 248 XE_WARN_ON("failed to add user fence"); 249 user_fence_put(sync->ufence); 250 dma_fence_put(fence); 251 } 252 } 253 } 254 255 void xe_sync_entry_cleanup(struct xe_sync_entry *sync) 256 { 257 if (sync->syncobj) 258 drm_syncobj_put(sync->syncobj); 259 dma_fence_put(sync->fence); 260 dma_fence_chain_free(sync->chain_fence); 261 if (sync->ufence) 262 user_fence_put(sync->ufence); 263 } 264 265 /** 266 * xe_sync_in_fence_get() - Get a fence from syncs, exec queue, and VM 267 * @sync: input syncs 268 * @num_sync: number of syncs 269 * @q: exec queue 270 * @vm: VM 271 * 272 * Get a fence from syncs, exec queue, and VM. If syncs contain in-fences create 273 * and return a composite fence of all in-fences + last fence. If no in-fences 274 * return last fence on input exec queue. Caller must drop reference to 275 * returned fence. 276 * 277 * Return: fence on success, ERR_PTR(-ENOMEM) on failure 278 */ 279 struct dma_fence * 280 xe_sync_in_fence_get(struct xe_sync_entry *sync, int num_sync, 281 struct xe_exec_queue *q, struct xe_vm *vm) 282 { 283 struct dma_fence **fences = NULL; 284 struct dma_fence_array *cf = NULL; 285 struct dma_fence *fence; 286 int i, num_in_fence = 0, current_fence = 0; 287 288 lockdep_assert_held(&vm->lock); 289 290 /* Count in-fences */ 291 for (i = 0; i < num_sync; ++i) { 292 if (sync[i].fence) { 293 ++num_in_fence; 294 fence = sync[i].fence; 295 } 296 } 297 298 /* Easy case... */ 299 if (!num_in_fence) { 300 fence = xe_exec_queue_last_fence_get(q, vm); 301 return fence; 302 } 303 304 /* Create composite fence */ 305 fences = kmalloc_array(num_in_fence + 1, sizeof(*fences), GFP_KERNEL); 306 if (!fences) 307 return ERR_PTR(-ENOMEM); 308 for (i = 0; i < num_sync; ++i) { 309 if (sync[i].fence) { 310 dma_fence_get(sync[i].fence); 311 fences[current_fence++] = sync[i].fence; 312 } 313 } 314 fences[current_fence++] = xe_exec_queue_last_fence_get(q, vm); 315 cf = dma_fence_array_create(num_in_fence, fences, 316 vm->composite_fence_ctx, 317 vm->composite_fence_seqno++, 318 false); 319 if (!cf) { 320 --vm->composite_fence_seqno; 321 goto err_out; 322 } 323 324 return &cf->base; 325 326 err_out: 327 while (current_fence) 328 dma_fence_put(fences[--current_fence]); 329 kfree(fences); 330 kfree(cf); 331 332 return ERR_PTR(-ENOMEM); 333 } 334 335 /** 336 * __xe_sync_ufence_get() - Get user fence from user fence 337 * @ufence: input user fence 338 * 339 * Get a user fence reference from user fence 340 * 341 * Return: xe_user_fence pointer with reference 342 */ 343 struct xe_user_fence *__xe_sync_ufence_get(struct xe_user_fence *ufence) 344 { 345 user_fence_get(ufence); 346 347 return ufence; 348 } 349 350 /** 351 * xe_sync_ufence_get() - Get user fence from sync 352 * @sync: input sync 353 * 354 * Get a user fence reference from sync. 355 * 356 * Return: xe_user_fence pointer with reference 357 */ 358 struct xe_user_fence *xe_sync_ufence_get(struct xe_sync_entry *sync) 359 { 360 user_fence_get(sync->ufence); 361 362 return sync->ufence; 363 } 364 365 /** 366 * xe_sync_ufence_put() - Put user fence reference 367 * @ufence: user fence reference 368 * 369 */ 370 void xe_sync_ufence_put(struct xe_user_fence *ufence) 371 { 372 user_fence_put(ufence); 373 } 374 375 /** 376 * xe_sync_ufence_get_status() - Get user fence status 377 * @ufence: user fence 378 * 379 * Return: 1 if signalled, 0 not signalled, <0 on error 380 */ 381 int xe_sync_ufence_get_status(struct xe_user_fence *ufence) 382 { 383 return READ_ONCE(ufence->signalled); 384 } 385