1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2022 Intel Corporation 4 */ 5 6 #include "xe_exec.h" 7 8 #include <drm/drm_device.h> 9 #include <drm/drm_exec.h> 10 #include <drm/drm_file.h> 11 #include <uapi/drm/xe_drm.h> 12 #include <linux/delay.h> 13 14 #include "xe_bo.h" 15 #include "xe_device.h" 16 #include "xe_exec_queue.h" 17 #include "xe_hw_engine_group.h" 18 #include "xe_macros.h" 19 #include "xe_pm.h" 20 #include "xe_ring_ops_types.h" 21 #include "xe_sched_job.h" 22 #include "xe_sync.h" 23 #include "xe_svm.h" 24 #include "xe_trace.h" 25 #include "xe_vm.h" 26 27 /** 28 * DOC: Execbuf (User GPU command submission) 29 * 30 * Execs have historically been rather complicated in DRM drivers (at least in 31 * the i915) because a few things: 32 * 33 * - Passing in a list BO which are read / written to creating implicit syncs 34 * - Binding at exec time 35 * - Flow controlling the ring at exec time 36 * 37 * In Xe we avoid all of this complication by not allowing a BO list to be 38 * passed into an exec, using the dma-buf implicit sync uAPI, have binds as 39 * separate operations, and using the DRM scheduler to flow control the ring. 40 * Let's deep dive on each of these. 41 * 42 * We can get away from a BO list by forcing the user to use in / out fences on 43 * every exec rather than the kernel tracking dependencies of BO (e.g. if the 44 * user knows an exec writes to a BO and reads from the BO in the next exec, it 45 * is the user's responsibility to pass in / out fence between the two execs). 46 * 47 * We do not allow a user to trigger a bind at exec time rather we have a VM 48 * bind IOCTL which uses the same in / out fence interface as exec. In that 49 * sense, a VM bind is basically the same operation as an exec from the user 50 * perspective. e.g. If an exec depends on a VM bind use the in / out fence 51 * interface (struct drm_xe_sync) to synchronize like syncing between two 52 * dependent execs. 53 * 54 * Although a user cannot trigger a bind, we still have to rebind userptrs in 55 * the VM that have been invalidated since the last exec, likewise we also have 56 * to rebind BOs that have been evicted by the kernel. We schedule these rebinds 57 * behind any pending kernel operations on any external BOs in VM or any BOs 58 * private to the VM. This is accomplished by the rebinds waiting on BOs 59 * DMA_RESV_USAGE_KERNEL slot (kernel ops) and kernel ops waiting on all BOs 60 * slots (inflight execs are in the DMA_RESV_USAGE_BOOKKEEP for private BOs and 61 * for external BOs). 62 * 63 * Rebinds / dma-resv usage applies to non-compute mode VMs only as for compute 64 * mode VMs we use preempt fences and a rebind worker (TODO: add link). 65 * 66 * There is no need to flow control the ring in the exec as we write the ring at 67 * submission time and set the DRM scheduler max job limit SIZE_OF_RING / 68 * MAX_JOB_SIZE. The DRM scheduler will then hold all jobs until space in the 69 * ring is available. 70 * 71 * All of this results in a rather simple exec implementation. 72 * 73 * Flow 74 * ~~~~ 75 * 76 * .. code-block:: 77 * 78 * Parse input arguments 79 * Wait for any async VM bind passed as in-fences to start 80 * <----------------------------------------------------------------------| 81 * Lock global VM lock in read mode | 82 * Pin userptrs (also finds userptr invalidated since last exec) | 83 * Lock exec (VM dma-resv lock, external BOs dma-resv locks) | 84 * Validate BOs that have been evicted | 85 * Create job | 86 * Rebind invalidated userptrs + evicted BOs (non-compute-mode) | 87 * Add rebind fence dependency to job | 88 * Add job VM dma-resv bookkeeping slot (non-compute mode) | 89 * Add job to external BOs dma-resv write slots (non-compute mode) | 90 * Check if any userptrs invalidated since pin ------ Drop locks ---------| 91 * Install in / out fences for job 92 * Submit job 93 * Unlock all 94 */ 95 96 /* 97 * Add validation and rebinding to the drm_exec locking loop, since both can 98 * trigger eviction which may require sleeping dma_resv locks. 99 */ 100 static int xe_exec_fn(struct drm_gpuvm_exec *vm_exec) 101 { 102 struct xe_vm *vm = container_of(vm_exec->vm, struct xe_vm, gpuvm); 103 int ret; 104 105 /* The fence slot added here is intended for the exec sched job. */ 106 xe_vm_set_validation_exec(vm, &vm_exec->exec); 107 ret = xe_vm_validate_rebind(vm, &vm_exec->exec, 1); 108 xe_vm_set_validation_exec(vm, NULL); 109 return ret; 110 } 111 112 int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file) 113 { 114 struct xe_device *xe = to_xe_device(dev); 115 struct xe_file *xef = to_xe_file(file); 116 struct drm_xe_exec *args = data; 117 struct drm_xe_sync __user *syncs_user = u64_to_user_ptr(args->syncs); 118 u64 __user *addresses_user = u64_to_user_ptr(args->address); 119 struct xe_exec_queue *q; 120 struct xe_sync_entry *syncs = NULL; 121 u64 addresses[XE_HW_ENGINE_MAX_INSTANCE]; 122 struct drm_gpuvm_exec vm_exec = {.extra.fn = xe_exec_fn}; 123 struct drm_exec *exec = &vm_exec.exec; 124 u32 i, num_syncs, num_ufence = 0; 125 struct xe_validation_ctx ctx; 126 struct xe_sched_job *job; 127 struct xe_vm *vm; 128 bool write_locked; 129 int err = 0; 130 struct xe_hw_engine_group *group; 131 enum xe_hw_engine_group_execution_mode mode, previous_mode; 132 133 if (XE_IOCTL_DBG(xe, args->extensions) || 134 XE_IOCTL_DBG(xe, args->pad[0] || args->pad[1] || args->pad[2]) || 135 XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1])) 136 return -EINVAL; 137 138 q = xe_exec_queue_lookup(xef, args->exec_queue_id); 139 if (XE_IOCTL_DBG(xe, !q)) 140 return -ENOENT; 141 142 if (XE_IOCTL_DBG(xe, q->flags & EXEC_QUEUE_FLAG_VM)) { 143 err = -EINVAL; 144 goto err_exec_queue; 145 } 146 147 if (XE_IOCTL_DBG(xe, args->num_batch_buffer && 148 q->width != args->num_batch_buffer)) { 149 err = -EINVAL; 150 goto err_exec_queue; 151 } 152 153 if (XE_IOCTL_DBG(xe, q->ops->reset_status(q))) { 154 err = -ECANCELED; 155 goto err_exec_queue; 156 } 157 158 if (atomic_read(&q->job_cnt) >= XE_MAX_JOB_COUNT_PER_EXEC_QUEUE) { 159 trace_xe_exec_queue_reach_max_job_count(q, XE_MAX_JOB_COUNT_PER_EXEC_QUEUE); 160 err = -EAGAIN; 161 goto err_exec_queue; 162 } 163 164 if (args->num_syncs) { 165 syncs = kcalloc(args->num_syncs, sizeof(*syncs), GFP_KERNEL); 166 if (!syncs) { 167 err = -ENOMEM; 168 goto err_exec_queue; 169 } 170 } 171 172 vm = q->vm; 173 174 for (num_syncs = 0; num_syncs < args->num_syncs; num_syncs++) { 175 err = xe_sync_entry_parse(xe, xef, &syncs[num_syncs], 176 &syncs_user[num_syncs], NULL, 0, 177 SYNC_PARSE_FLAG_EXEC | 178 (xe_vm_in_lr_mode(vm) ? 179 SYNC_PARSE_FLAG_LR_MODE : 0)); 180 if (err) 181 goto err_syncs; 182 183 if (xe_sync_is_ufence(&syncs[num_syncs])) 184 num_ufence++; 185 } 186 187 if (XE_IOCTL_DBG(xe, num_ufence > 1)) { 188 err = -EINVAL; 189 goto err_syncs; 190 } 191 192 if (xe_exec_queue_is_parallel(q)) { 193 err = copy_from_user(addresses, addresses_user, sizeof(u64) * 194 q->width); 195 if (err) { 196 err = -EFAULT; 197 goto err_syncs; 198 } 199 } 200 201 group = q->hwe->hw_engine_group; 202 mode = xe_hw_engine_group_find_exec_mode(q); 203 204 if (mode == EXEC_MODE_DMA_FENCE) { 205 err = xe_hw_engine_group_get_mode(group, mode, &previous_mode); 206 if (err) 207 goto err_syncs; 208 } 209 210 retry: 211 if (!xe_vm_in_lr_mode(vm) && xe_vm_userptr_check_repin(vm)) { 212 err = down_write_killable(&vm->lock); 213 write_locked = true; 214 } else { 215 /* We don't allow execs while the VM is in error state */ 216 err = down_read_interruptible(&vm->lock); 217 write_locked = false; 218 } 219 if (err) 220 goto err_hw_exec_mode; 221 222 if (write_locked) { 223 err = xe_vm_userptr_pin(vm); 224 downgrade_write(&vm->lock); 225 write_locked = false; 226 if (err) 227 goto err_unlock_list; 228 } 229 230 if (!args->num_batch_buffer) { 231 err = xe_vm_lock(vm, true); 232 if (err) 233 goto err_unlock_list; 234 235 if (!xe_vm_in_lr_mode(vm)) { 236 struct dma_fence *fence; 237 238 fence = xe_sync_in_fence_get(syncs, num_syncs, q, vm); 239 if (IS_ERR(fence)) { 240 err = PTR_ERR(fence); 241 xe_vm_unlock(vm); 242 goto err_unlock_list; 243 } 244 for (i = 0; i < num_syncs; i++) 245 xe_sync_entry_signal(&syncs[i], fence); 246 xe_exec_queue_last_fence_set(q, vm, fence); 247 dma_fence_put(fence); 248 } 249 250 xe_vm_unlock(vm); 251 goto err_unlock_list; 252 } 253 254 /* 255 * It's OK to block interruptible here with the vm lock held, since 256 * on task freezing during suspend / hibernate, the call will 257 * return -ERESTARTSYS and the IOCTL will be rerun. 258 */ 259 err = xe_pm_block_on_suspend(xe); 260 if (err) 261 goto err_unlock_list; 262 263 if (!xe_vm_in_lr_mode(vm)) { 264 vm_exec.vm = &vm->gpuvm; 265 vm_exec.flags = DRM_EXEC_INTERRUPTIBLE_WAIT; 266 err = xe_validation_exec_lock(&ctx, &vm_exec, &xe->val); 267 if (err) 268 goto err_unlock_list; 269 } 270 271 if (xe_vm_is_closed_or_banned(q->vm)) { 272 drm_warn(&xe->drm, "Trying to schedule after vm is closed or banned\n"); 273 err = -ECANCELED; 274 goto err_exec; 275 } 276 277 if (xe_exec_queue_uses_pxp(q)) { 278 err = xe_vm_validate_protected(q->vm); 279 if (err) 280 goto err_exec; 281 } 282 283 job = xe_sched_job_create(q, xe_exec_queue_is_parallel(q) ? 284 addresses : &args->address); 285 if (IS_ERR(job)) { 286 err = PTR_ERR(job); 287 goto err_exec; 288 } 289 290 /* Wait behind rebinds */ 291 if (!xe_vm_in_lr_mode(vm)) { 292 err = xe_sched_job_add_deps(job, 293 xe_vm_resv(vm), 294 DMA_RESV_USAGE_KERNEL); 295 if (err) 296 goto err_put_job; 297 } 298 299 for (i = 0; i < num_syncs && !err; i++) 300 err = xe_sync_entry_add_deps(&syncs[i], job); 301 if (err) 302 goto err_put_job; 303 304 if (!xe_vm_in_lr_mode(vm)) { 305 err = xe_svm_notifier_lock_interruptible(vm); 306 if (err) 307 goto err_put_job; 308 309 err = __xe_vm_userptr_needs_repin(vm); 310 if (err) 311 goto err_repin; 312 } 313 314 /* 315 * Point of no return, if we error after this point just set an error on 316 * the job and let the DRM scheduler / backend clean up the job. 317 */ 318 xe_sched_job_arm(job); 319 if (!xe_vm_in_lr_mode(vm)) 320 drm_gpuvm_resv_add_fence(&vm->gpuvm, exec, &job->drm.s_fence->finished, 321 DMA_RESV_USAGE_BOOKKEEP, 322 DMA_RESV_USAGE_BOOKKEEP); 323 324 for (i = 0; i < num_syncs; i++) { 325 xe_sync_entry_signal(&syncs[i], &job->drm.s_fence->finished); 326 xe_sched_job_init_user_fence(job, &syncs[i]); 327 } 328 329 if (!xe_vm_in_lr_mode(vm)) 330 xe_exec_queue_last_fence_set(q, vm, &job->drm.s_fence->finished); 331 xe_sched_job_push(job); 332 xe_vm_reactivate_rebind(vm); 333 334 if (!err && !xe_vm_in_lr_mode(vm)) { 335 spin_lock(&xe->ttm.lru_lock); 336 ttm_lru_bulk_move_tail(&vm->lru_bulk_move); 337 spin_unlock(&xe->ttm.lru_lock); 338 } 339 340 if (mode == EXEC_MODE_LR) 341 xe_hw_engine_group_resume_faulting_lr_jobs(group); 342 343 err_repin: 344 if (!xe_vm_in_lr_mode(vm)) 345 xe_svm_notifier_unlock(vm); 346 err_put_job: 347 if (err) 348 xe_sched_job_put(job); 349 err_exec: 350 if (!xe_vm_in_lr_mode(vm)) 351 xe_validation_ctx_fini(&ctx); 352 err_unlock_list: 353 up_read(&vm->lock); 354 if (err == -EAGAIN) 355 goto retry; 356 err_hw_exec_mode: 357 if (mode == EXEC_MODE_DMA_FENCE) 358 xe_hw_engine_group_put(group); 359 err_syncs: 360 while (num_syncs--) 361 xe_sync_entry_cleanup(&syncs[num_syncs]); 362 kfree(syncs); 363 err_exec_queue: 364 xe_exec_queue_put(q); 365 366 return err; 367 } 368