1 // SPDX-License-Identifier: MIT
2 
3 #include <drm/drm_exec.h>
4 
5 #include "nouveau_drv.h"
6 #include "nouveau_gem.h"
7 #include "nouveau_mem.h"
8 #include "nouveau_dma.h"
9 #include "nouveau_exec.h"
10 #include "nouveau_abi16.h"
11 #include "nouveau_chan.h"
12 #include "nouveau_sched.h"
13 #include "nouveau_uvmm.h"
14 
15 /**
16  * DOC: Overview
17  *
18  * Nouveau's VM_BIND / EXEC UAPI consists of three ioctls: DRM_NOUVEAU_VM_INIT,
19  * DRM_NOUVEAU_VM_BIND and DRM_NOUVEAU_EXEC.
20  *
21  * In order to use the UAPI firstly a user client must initialize the VA space
22  * using the DRM_NOUVEAU_VM_INIT ioctl specifying which region of the VA space
23  * should be managed by the kernel and which by the UMD.
24  *
25  * The DRM_NOUVEAU_VM_BIND ioctl provides clients an interface to manage the
26  * userspace-managable portion of the VA space. It provides operations to map
27  * and unmap memory. Mappings may be flagged as sparse. Sparse mappings are not
28  * backed by a GEM object and the kernel will ignore GEM handles provided
29  * alongside a sparse mapping.
30  *
31  * Userspace may request memory backed mappings either within or outside of the
32  * bounds (but not crossing those bounds) of a previously mapped sparse
33  * mapping. Subsequently requested memory backed mappings within a sparse
34  * mapping will take precedence over the corresponding range of the sparse
35  * mapping. If such memory backed mappings are unmapped the kernel will make
36  * sure that the corresponding sparse mapping will take their place again.
37  * Requests to unmap a sparse mapping that still contains memory backed mappings
38  * will result in those memory backed mappings being unmapped first.
39  *
40  * Unmap requests are not bound to the range of existing mappings and can even
41  * overlap the bounds of sparse mappings. For such a request the kernel will
42  * make sure to unmap all memory backed mappings within the given range,
43  * splitting up memory backed mappings which are only partially contained
44  * within the given range. Unmap requests with the sparse flag set must match
45  * the range of a previously mapped sparse mapping exactly though.
46  *
47  * While the kernel generally permits arbitrary sequences and ranges of memory
48  * backed mappings being mapped and unmapped, either within a single or multiple
49  * VM_BIND ioctl calls, there are some restrictions for sparse mappings.
50  *
51  * The kernel does not permit to:
52  *   - unmap non-existent sparse mappings
53  *   - unmap a sparse mapping and map a new sparse mapping overlapping the range
54  *     of the previously unmapped sparse mapping within the same VM_BIND ioctl
55  *   - unmap a sparse mapping and map new memory backed mappings overlapping the
56  *     range of the previously unmapped sparse mapping within the same VM_BIND
57  *     ioctl
58  *
59  * When using the VM_BIND ioctl to request the kernel to map memory to a given
60  * virtual address in the GPU's VA space there is no guarantee that the actual
61  * mappings are created in the GPU's MMU. If the given memory is swapped out
62  * at the time the bind operation is executed the kernel will stash the mapping
63  * details into it's internal alloctor and create the actual MMU mappings once
64  * the memory is swapped back in. While this is transparent for userspace, it is
65  * guaranteed that all the backing memory is swapped back in and all the memory
66  * mappings, as requested by userspace previously, are actually mapped once the
67  * DRM_NOUVEAU_EXEC ioctl is called to submit an exec job.
68  *
69  * A VM_BIND job can be executed either synchronously or asynchronously. If
70  * exectued asynchronously, userspace may provide a list of syncobjs this job
71  * will wait for and/or a list of syncobj the kernel will signal once the
72  * VM_BIND job finished execution. If executed synchronously the ioctl will
73  * block until the bind job is finished. For synchronous jobs the kernel will
74  * not permit any syncobjs submitted to the kernel.
75  *
76  * To execute a push buffer the UAPI provides the DRM_NOUVEAU_EXEC ioctl. EXEC
77  * jobs are always executed asynchronously, and, equal to VM_BIND jobs, provide
78  * the option to synchronize them with syncobjs.
79  *
80  * Besides that, EXEC jobs can be scheduled for a specified channel to execute on.
81  *
82  * Since VM_BIND jobs update the GPU's VA space on job submit, EXEC jobs do have
83  * an up to date view of the VA space. However, the actual mappings might still
84  * be pending. Hence, EXEC jobs require to have the particular fences - of
85  * the corresponding VM_BIND jobs they depent on - attached to them.
86  */
87 
88 static int
89 nouveau_exec_job_submit(struct nouveau_job *job)
90 {
91 	struct nouveau_exec_job *exec_job = to_nouveau_exec_job(job);
92 	struct nouveau_cli *cli = job->cli;
93 	struct nouveau_uvmm *uvmm = nouveau_cli_uvmm(cli);
94 	struct drm_exec *exec = &job->exec;
95 	struct drm_gem_object *obj;
96 	unsigned long index;
97 	int ret;
98 
99 	/* Create a new fence, but do not emit yet. */
100 	ret = nouveau_fence_create(&exec_job->fence, exec_job->chan);
101 	if (ret)
102 		return ret;
103 
104 	nouveau_uvmm_lock(uvmm);
105 	drm_exec_init(exec, DRM_EXEC_INTERRUPTIBLE_WAIT |
106 			    DRM_EXEC_IGNORE_DUPLICATES);
107 	drm_exec_until_all_locked(exec) {
108 		struct drm_gpuva *va;
109 
110 		drm_gpuva_for_each_va(va, &uvmm->umgr) {
111 			if (unlikely(va == &uvmm->umgr.kernel_alloc_node))
112 				continue;
113 
114 			ret = drm_exec_prepare_obj(exec, va->gem.obj, 1);
115 			drm_exec_retry_on_contention(exec);
116 			if (ret)
117 				goto err_uvmm_unlock;
118 		}
119 	}
120 	nouveau_uvmm_unlock(uvmm);
121 
122 	drm_exec_for_each_locked_object(exec, index, obj) {
123 		struct nouveau_bo *nvbo = nouveau_gem_object(obj);
124 
125 		ret = nouveau_bo_validate(nvbo, true, false);
126 		if (ret)
127 			goto err_exec_fini;
128 	}
129 
130 	return 0;
131 
132 err_uvmm_unlock:
133 	nouveau_uvmm_unlock(uvmm);
134 err_exec_fini:
135 	drm_exec_fini(exec);
136 	return ret;
137 
138 }
139 
140 static void
141 nouveau_exec_job_armed_submit(struct nouveau_job *job)
142 {
143 	struct drm_exec *exec = &job->exec;
144 	struct drm_gem_object *obj;
145 	unsigned long index;
146 
147 	drm_exec_for_each_locked_object(exec, index, obj)
148 		dma_resv_add_fence(obj->resv, job->done_fence, job->resv_usage);
149 
150 	drm_exec_fini(exec);
151 }
152 
153 static struct dma_fence *
154 nouveau_exec_job_run(struct nouveau_job *job)
155 {
156 	struct nouveau_exec_job *exec_job = to_nouveau_exec_job(job);
157 	struct nouveau_channel *chan = exec_job->chan;
158 	struct nouveau_fence *fence = exec_job->fence;
159 	int i, ret;
160 
161 	ret = nouveau_dma_wait(chan, exec_job->push.count + 1, 16);
162 	if (ret) {
163 		NV_PRINTK(err, job->cli, "nv50cal_space: %d\n", ret);
164 		return ERR_PTR(ret);
165 	}
166 
167 	for (i = 0; i < exec_job->push.count; i++) {
168 		struct drm_nouveau_exec_push *p = &exec_job->push.s[i];
169 		bool no_prefetch = p->flags & DRM_NOUVEAU_EXEC_PUSH_NO_PREFETCH;
170 
171 		nv50_dma_push(chan, p->va, p->va_len, no_prefetch);
172 	}
173 
174 	ret = nouveau_fence_emit(fence);
175 	if (ret) {
176 		nouveau_fence_unref(&exec_job->fence);
177 		NV_PRINTK(err, job->cli, "error fencing pushbuf: %d\n", ret);
178 		WIND_RING(chan);
179 		return ERR_PTR(ret);
180 	}
181 
182 	/* The fence was emitted successfully, set the job's fence pointer to
183 	 * NULL in order to avoid freeing it up when the job is cleaned up.
184 	 */
185 	exec_job->fence = NULL;
186 
187 	return &fence->base;
188 }
189 
190 static void
191 nouveau_exec_job_free(struct nouveau_job *job)
192 {
193 	struct nouveau_exec_job *exec_job = to_nouveau_exec_job(job);
194 
195 	nouveau_job_free(job);
196 
197 	kfree(exec_job->fence);
198 	kfree(exec_job->push.s);
199 	kfree(exec_job);
200 }
201 
202 static enum drm_gpu_sched_stat
203 nouveau_exec_job_timeout(struct nouveau_job *job)
204 {
205 	struct nouveau_exec_job *exec_job = to_nouveau_exec_job(job);
206 	struct nouveau_channel *chan = exec_job->chan;
207 
208 	if (unlikely(!atomic_read(&chan->killed)))
209 		nouveau_channel_kill(chan);
210 
211 	NV_PRINTK(warn, job->cli, "job timeout, channel %d killed!\n",
212 		  chan->chid);
213 
214 	nouveau_sched_entity_fini(job->entity);
215 
216 	return DRM_GPU_SCHED_STAT_NOMINAL;
217 }
218 
219 static struct nouveau_job_ops nouveau_exec_job_ops = {
220 	.submit = nouveau_exec_job_submit,
221 	.armed_submit = nouveau_exec_job_armed_submit,
222 	.run = nouveau_exec_job_run,
223 	.free = nouveau_exec_job_free,
224 	.timeout = nouveau_exec_job_timeout,
225 };
226 
227 int
228 nouveau_exec_job_init(struct nouveau_exec_job **pjob,
229 		      struct nouveau_exec_job_args *__args)
230 {
231 	struct nouveau_exec_job *job;
232 	struct nouveau_job_args args = {};
233 	int i, ret;
234 
235 	for (i = 0; i < __args->push.count; i++) {
236 		struct drm_nouveau_exec_push *p = &__args->push.s[i];
237 
238 		if (unlikely(p->va_len > NV50_DMA_PUSH_MAX_LENGTH)) {
239 			NV_PRINTK(err, nouveau_cli(__args->file_priv),
240 				  "pushbuf size exceeds limit: 0x%x max 0x%x\n",
241 				  p->va_len, NV50_DMA_PUSH_MAX_LENGTH);
242 			return -EINVAL;
243 		}
244 	}
245 
246 	job = *pjob = kzalloc(sizeof(*job), GFP_KERNEL);
247 	if (!job)
248 		return -ENOMEM;
249 
250 	job->push.count = __args->push.count;
251 	if (__args->push.count) {
252 		job->push.s = kmemdup(__args->push.s,
253 				      sizeof(*__args->push.s) *
254 				      __args->push.count,
255 				      GFP_KERNEL);
256 		if (!job->push.s) {
257 			ret = -ENOMEM;
258 			goto err_free_job;
259 		}
260 	}
261 
262 	job->chan = __args->chan;
263 
264 	args.sched_entity = __args->sched_entity;
265 	args.file_priv = __args->file_priv;
266 
267 	args.in_sync.count = __args->in_sync.count;
268 	args.in_sync.s = __args->in_sync.s;
269 
270 	args.out_sync.count = __args->out_sync.count;
271 	args.out_sync.s = __args->out_sync.s;
272 
273 	args.ops = &nouveau_exec_job_ops;
274 	args.resv_usage = DMA_RESV_USAGE_WRITE;
275 
276 	ret = nouveau_job_init(&job->base, &args);
277 	if (ret)
278 		goto err_free_pushs;
279 
280 	return 0;
281 
282 err_free_pushs:
283 	kfree(job->push.s);
284 err_free_job:
285 	kfree(job);
286 	*pjob = NULL;
287 
288 	return ret;
289 }
290 
291 static int
292 nouveau_exec(struct nouveau_exec_job_args *args)
293 {
294 	struct nouveau_exec_job *job;
295 	int ret;
296 
297 	ret = nouveau_exec_job_init(&job, args);
298 	if (ret)
299 		return ret;
300 
301 	ret = nouveau_job_submit(&job->base);
302 	if (ret)
303 		goto err_job_fini;
304 
305 	return 0;
306 
307 err_job_fini:
308 	nouveau_job_fini(&job->base);
309 	return ret;
310 }
311 
312 static int
313 nouveau_exec_ucopy(struct nouveau_exec_job_args *args,
314 		   struct drm_nouveau_exec *req)
315 {
316 	struct drm_nouveau_sync **s;
317 	u32 inc = req->wait_count;
318 	u64 ins = req->wait_ptr;
319 	u32 outc = req->sig_count;
320 	u64 outs = req->sig_ptr;
321 	u32 pushc = req->push_count;
322 	u64 pushs = req->push_ptr;
323 	int ret;
324 
325 	if (pushc) {
326 		args->push.count = pushc;
327 		args->push.s = u_memcpya(pushs, pushc, sizeof(*args->push.s));
328 		if (IS_ERR(args->push.s))
329 			return PTR_ERR(args->push.s);
330 	}
331 
332 	if (inc) {
333 		s = &args->in_sync.s;
334 
335 		args->in_sync.count = inc;
336 		*s = u_memcpya(ins, inc, sizeof(**s));
337 		if (IS_ERR(*s)) {
338 			ret = PTR_ERR(*s);
339 			goto err_free_pushs;
340 		}
341 	}
342 
343 	if (outc) {
344 		s = &args->out_sync.s;
345 
346 		args->out_sync.count = outc;
347 		*s = u_memcpya(outs, outc, sizeof(**s));
348 		if (IS_ERR(*s)) {
349 			ret = PTR_ERR(*s);
350 			goto err_free_ins;
351 		}
352 	}
353 
354 	return 0;
355 
356 err_free_pushs:
357 	u_free(args->push.s);
358 err_free_ins:
359 	u_free(args->in_sync.s);
360 	return ret;
361 }
362 
363 static void
364 nouveau_exec_ufree(struct nouveau_exec_job_args *args)
365 {
366 	u_free(args->push.s);
367 	u_free(args->in_sync.s);
368 	u_free(args->out_sync.s);
369 }
370 
371 int
372 nouveau_exec_ioctl_exec(struct drm_device *dev,
373 			void *data,
374 			struct drm_file *file_priv)
375 {
376 	struct nouveau_abi16 *abi16 = nouveau_abi16_get(file_priv);
377 	struct nouveau_cli *cli = nouveau_cli(file_priv);
378 	struct nouveau_abi16_chan *chan16;
379 	struct nouveau_channel *chan = NULL;
380 	struct nouveau_exec_job_args args = {};
381 	struct drm_nouveau_exec *req = data;
382 	int push_max, ret = 0;
383 
384 	if (unlikely(!abi16))
385 		return -ENOMEM;
386 
387 	/* abi16 locks already */
388 	if (unlikely(!nouveau_cli_uvmm(cli)))
389 		return nouveau_abi16_put(abi16, -ENOSYS);
390 
391 	list_for_each_entry(chan16, &abi16->channels, head) {
392 		if (chan16->chan->chid == req->channel) {
393 			chan = chan16->chan;
394 			break;
395 		}
396 	}
397 
398 	if (!chan)
399 		return nouveau_abi16_put(abi16, -ENOENT);
400 
401 	if (unlikely(atomic_read(&chan->killed)))
402 		return nouveau_abi16_put(abi16, -ENODEV);
403 
404 	if (!chan->dma.ib_max)
405 		return nouveau_abi16_put(abi16, -ENOSYS);
406 
407 	push_max = nouveau_exec_push_max_from_ib_max(chan->dma.ib_max);
408 	if (unlikely(req->push_count > push_max)) {
409 		NV_PRINTK(err, cli, "pushbuf push count exceeds limit: %d max %d\n",
410 			  req->push_count, push_max);
411 		return nouveau_abi16_put(abi16, -EINVAL);
412 	}
413 
414 	ret = nouveau_exec_ucopy(&args, req);
415 	if (ret)
416 		goto out;
417 
418 	args.sched_entity = &chan16->sched_entity;
419 	args.file_priv = file_priv;
420 	args.chan = chan;
421 
422 	ret = nouveau_exec(&args);
423 	if (ret)
424 		goto out_free_args;
425 
426 out_free_args:
427 	nouveau_exec_ufree(&args);
428 out:
429 	return nouveau_abi16_put(abi16, ret);
430 }
431