xref: /openbmc/linux/drivers/misc/uacce/uacce.c (revision be58f710)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 #include <linux/compat.h>
3 #include <linux/dma-mapping.h>
4 #include <linux/iommu.h>
5 #include <linux/module.h>
6 #include <linux/poll.h>
7 #include <linux/slab.h>
8 #include <linux/uacce.h>
9 
10 static struct class *uacce_class;
11 static dev_t uacce_devt;
12 static DEFINE_MUTEX(uacce_mutex);
13 static DEFINE_XARRAY_ALLOC(uacce_xa);
14 
15 static int uacce_start_queue(struct uacce_queue *q)
16 {
17 	int ret = 0;
18 
19 	mutex_lock(&uacce_mutex);
20 
21 	if (q->state != UACCE_Q_INIT) {
22 		ret = -EINVAL;
23 		goto out_with_lock;
24 	}
25 
26 	if (q->uacce->ops->start_queue) {
27 		ret = q->uacce->ops->start_queue(q);
28 		if (ret < 0)
29 			goto out_with_lock;
30 	}
31 
32 	q->state = UACCE_Q_STARTED;
33 
34 out_with_lock:
35 	mutex_unlock(&uacce_mutex);
36 
37 	return ret;
38 }
39 
40 static int uacce_put_queue(struct uacce_queue *q)
41 {
42 	struct uacce_device *uacce = q->uacce;
43 
44 	mutex_lock(&uacce_mutex);
45 
46 	if (q->state == UACCE_Q_ZOMBIE)
47 		goto out;
48 
49 	if ((q->state == UACCE_Q_STARTED) && uacce->ops->stop_queue)
50 		uacce->ops->stop_queue(q);
51 
52 	if ((q->state == UACCE_Q_INIT || q->state == UACCE_Q_STARTED) &&
53 	     uacce->ops->put_queue)
54 		uacce->ops->put_queue(q);
55 
56 	q->state = UACCE_Q_ZOMBIE;
57 out:
58 	mutex_unlock(&uacce_mutex);
59 
60 	return 0;
61 }
62 
63 static long uacce_fops_unl_ioctl(struct file *filep,
64 				 unsigned int cmd, unsigned long arg)
65 {
66 	struct uacce_queue *q = filep->private_data;
67 	struct uacce_device *uacce = q->uacce;
68 
69 	switch (cmd) {
70 	case UACCE_CMD_START_Q:
71 		return uacce_start_queue(q);
72 
73 	case UACCE_CMD_PUT_Q:
74 		return uacce_put_queue(q);
75 
76 	default:
77 		if (!uacce->ops->ioctl)
78 			return -EINVAL;
79 
80 		return uacce->ops->ioctl(q, cmd, arg);
81 	}
82 }
83 
84 #ifdef CONFIG_COMPAT
85 static long uacce_fops_compat_ioctl(struct file *filep,
86 				   unsigned int cmd, unsigned long arg)
87 {
88 	arg = (unsigned long)compat_ptr(arg);
89 
90 	return uacce_fops_unl_ioctl(filep, cmd, arg);
91 }
92 #endif
93 
94 static int uacce_bind_queue(struct uacce_device *uacce, struct uacce_queue *q)
95 {
96 	u32 pasid;
97 	struct iommu_sva *handle;
98 
99 	if (!(uacce->flags & UACCE_DEV_SVA))
100 		return 0;
101 
102 	handle = iommu_sva_bind_device(uacce->parent, current->mm, NULL);
103 	if (IS_ERR(handle))
104 		return PTR_ERR(handle);
105 
106 	pasid = iommu_sva_get_pasid(handle);
107 	if (pasid == IOMMU_PASID_INVALID) {
108 		iommu_sva_unbind_device(handle);
109 		return -ENODEV;
110 	}
111 
112 	q->handle = handle;
113 	q->pasid = pasid;
114 	return 0;
115 }
116 
117 static void uacce_unbind_queue(struct uacce_queue *q)
118 {
119 	if (!q->handle)
120 		return;
121 	iommu_sva_unbind_device(q->handle);
122 	q->handle = NULL;
123 }
124 
125 static int uacce_fops_open(struct inode *inode, struct file *filep)
126 {
127 	struct uacce_device *uacce;
128 	struct uacce_queue *q;
129 	int ret;
130 
131 	uacce = xa_load(&uacce_xa, iminor(inode));
132 	if (!uacce)
133 		return -ENODEV;
134 
135 	q = kzalloc(sizeof(struct uacce_queue), GFP_KERNEL);
136 	if (!q)
137 		return -ENOMEM;
138 
139 	ret = uacce_bind_queue(uacce, q);
140 	if (ret)
141 		goto out_with_mem;
142 
143 	q->uacce = uacce;
144 
145 	if (uacce->ops->get_queue) {
146 		ret = uacce->ops->get_queue(uacce, q->pasid, q);
147 		if (ret < 0)
148 			goto out_with_bond;
149 	}
150 
151 	init_waitqueue_head(&q->wait);
152 	filep->private_data = q;
153 	uacce->inode = inode;
154 	q->state = UACCE_Q_INIT;
155 
156 	mutex_lock(&uacce->queues_lock);
157 	list_add(&q->list, &uacce->queues);
158 	mutex_unlock(&uacce->queues_lock);
159 
160 	return 0;
161 
162 out_with_bond:
163 	uacce_unbind_queue(q);
164 out_with_mem:
165 	kfree(q);
166 	return ret;
167 }
168 
169 static int uacce_fops_release(struct inode *inode, struct file *filep)
170 {
171 	struct uacce_queue *q = filep->private_data;
172 
173 	mutex_lock(&q->uacce->queues_lock);
174 	list_del(&q->list);
175 	mutex_unlock(&q->uacce->queues_lock);
176 	uacce_put_queue(q);
177 	uacce_unbind_queue(q);
178 	kfree(q);
179 
180 	return 0;
181 }
182 
183 static void uacce_vma_close(struct vm_area_struct *vma)
184 {
185 	struct uacce_queue *q = vma->vm_private_data;
186 	struct uacce_qfile_region *qfr = NULL;
187 
188 	if (vma->vm_pgoff < UACCE_MAX_REGION)
189 		qfr = q->qfrs[vma->vm_pgoff];
190 
191 	kfree(qfr);
192 }
193 
194 static const struct vm_operations_struct uacce_vm_ops = {
195 	.close = uacce_vma_close,
196 };
197 
198 static int uacce_fops_mmap(struct file *filep, struct vm_area_struct *vma)
199 {
200 	struct uacce_queue *q = filep->private_data;
201 	struct uacce_device *uacce = q->uacce;
202 	struct uacce_qfile_region *qfr;
203 	enum uacce_qfrt type = UACCE_MAX_REGION;
204 	int ret = 0;
205 
206 	if (vma->vm_pgoff < UACCE_MAX_REGION)
207 		type = vma->vm_pgoff;
208 	else
209 		return -EINVAL;
210 
211 	qfr = kzalloc(sizeof(*qfr), GFP_KERNEL);
212 	if (!qfr)
213 		return -ENOMEM;
214 
215 	vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND | VM_WIPEONFORK;
216 	vma->vm_ops = &uacce_vm_ops;
217 	vma->vm_private_data = q;
218 	qfr->type = type;
219 
220 	mutex_lock(&uacce_mutex);
221 
222 	if (q->state != UACCE_Q_INIT && q->state != UACCE_Q_STARTED) {
223 		ret = -EINVAL;
224 		goto out_with_lock;
225 	}
226 
227 	if (q->qfrs[type]) {
228 		ret = -EEXIST;
229 		goto out_with_lock;
230 	}
231 
232 	switch (type) {
233 	case UACCE_QFRT_MMIO:
234 	case UACCE_QFRT_DUS:
235 		if (!uacce->ops->mmap) {
236 			ret = -EINVAL;
237 			goto out_with_lock;
238 		}
239 
240 		ret = uacce->ops->mmap(q, vma, qfr);
241 		if (ret)
242 			goto out_with_lock;
243 		break;
244 
245 	default:
246 		ret = -EINVAL;
247 		goto out_with_lock;
248 	}
249 
250 	q->qfrs[type] = qfr;
251 	mutex_unlock(&uacce_mutex);
252 
253 	return ret;
254 
255 out_with_lock:
256 	mutex_unlock(&uacce_mutex);
257 	kfree(qfr);
258 	return ret;
259 }
260 
261 static __poll_t uacce_fops_poll(struct file *file, poll_table *wait)
262 {
263 	struct uacce_queue *q = file->private_data;
264 	struct uacce_device *uacce = q->uacce;
265 
266 	poll_wait(file, &q->wait, wait);
267 	if (uacce->ops->is_q_updated && uacce->ops->is_q_updated(q))
268 		return EPOLLIN | EPOLLRDNORM;
269 
270 	return 0;
271 }
272 
273 static const struct file_operations uacce_fops = {
274 	.owner		= THIS_MODULE,
275 	.open		= uacce_fops_open,
276 	.release	= uacce_fops_release,
277 	.unlocked_ioctl	= uacce_fops_unl_ioctl,
278 #ifdef CONFIG_COMPAT
279 	.compat_ioctl	= uacce_fops_compat_ioctl,
280 #endif
281 	.mmap		= uacce_fops_mmap,
282 	.poll		= uacce_fops_poll,
283 };
284 
285 #define to_uacce_device(dev) container_of(dev, struct uacce_device, dev)
286 
287 static ssize_t api_show(struct device *dev,
288 			struct device_attribute *attr, char *buf)
289 {
290 	struct uacce_device *uacce = to_uacce_device(dev);
291 
292 	return sprintf(buf, "%s\n", uacce->api_ver);
293 }
294 
295 static ssize_t flags_show(struct device *dev,
296 			  struct device_attribute *attr, char *buf)
297 {
298 	struct uacce_device *uacce = to_uacce_device(dev);
299 
300 	return sprintf(buf, "%u\n", uacce->flags);
301 }
302 
303 static ssize_t available_instances_show(struct device *dev,
304 					struct device_attribute *attr,
305 					char *buf)
306 {
307 	struct uacce_device *uacce = to_uacce_device(dev);
308 
309 	if (!uacce->ops->get_available_instances)
310 		return -ENODEV;
311 
312 	return sprintf(buf, "%d\n",
313 		       uacce->ops->get_available_instances(uacce));
314 }
315 
316 static ssize_t algorithms_show(struct device *dev,
317 			       struct device_attribute *attr, char *buf)
318 {
319 	struct uacce_device *uacce = to_uacce_device(dev);
320 
321 	return sprintf(buf, "%s\n", uacce->algs);
322 }
323 
324 static ssize_t region_mmio_size_show(struct device *dev,
325 				     struct device_attribute *attr, char *buf)
326 {
327 	struct uacce_device *uacce = to_uacce_device(dev);
328 
329 	return sprintf(buf, "%lu\n",
330 		       uacce->qf_pg_num[UACCE_QFRT_MMIO] << PAGE_SHIFT);
331 }
332 
333 static ssize_t region_dus_size_show(struct device *dev,
334 				    struct device_attribute *attr, char *buf)
335 {
336 	struct uacce_device *uacce = to_uacce_device(dev);
337 
338 	return sprintf(buf, "%lu\n",
339 		       uacce->qf_pg_num[UACCE_QFRT_DUS] << PAGE_SHIFT);
340 }
341 
342 static DEVICE_ATTR_RO(api);
343 static DEVICE_ATTR_RO(flags);
344 static DEVICE_ATTR_RO(available_instances);
345 static DEVICE_ATTR_RO(algorithms);
346 static DEVICE_ATTR_RO(region_mmio_size);
347 static DEVICE_ATTR_RO(region_dus_size);
348 
349 static struct attribute *uacce_dev_attrs[] = {
350 	&dev_attr_api.attr,
351 	&dev_attr_flags.attr,
352 	&dev_attr_available_instances.attr,
353 	&dev_attr_algorithms.attr,
354 	&dev_attr_region_mmio_size.attr,
355 	&dev_attr_region_dus_size.attr,
356 	NULL,
357 };
358 
359 static umode_t uacce_dev_is_visible(struct kobject *kobj,
360 				    struct attribute *attr, int n)
361 {
362 	struct device *dev = kobj_to_dev(kobj);
363 	struct uacce_device *uacce = to_uacce_device(dev);
364 
365 	if (((attr == &dev_attr_region_mmio_size.attr) &&
366 	    (!uacce->qf_pg_num[UACCE_QFRT_MMIO])) ||
367 	    ((attr == &dev_attr_region_dus_size.attr) &&
368 	    (!uacce->qf_pg_num[UACCE_QFRT_DUS])))
369 		return 0;
370 
371 	return attr->mode;
372 }
373 
374 static struct attribute_group uacce_dev_group = {
375 	.is_visible	= uacce_dev_is_visible,
376 	.attrs		= uacce_dev_attrs,
377 };
378 
379 __ATTRIBUTE_GROUPS(uacce_dev);
380 
381 static void uacce_release(struct device *dev)
382 {
383 	struct uacce_device *uacce = to_uacce_device(dev);
384 
385 	kfree(uacce);
386 }
387 
388 static unsigned int uacce_enable_sva(struct device *parent, unsigned int flags)
389 {
390 	int ret;
391 
392 	if (!(flags & UACCE_DEV_SVA))
393 		return flags;
394 
395 	flags &= ~UACCE_DEV_SVA;
396 
397 	ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_IOPF);
398 	if (ret) {
399 		dev_err(parent, "failed to enable IOPF feature! ret = %pe\n", ERR_PTR(ret));
400 		return flags;
401 	}
402 
403 	ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA);
404 	if (ret) {
405 		dev_err(parent, "failed to enable SVA feature! ret = %pe\n", ERR_PTR(ret));
406 		iommu_dev_disable_feature(parent, IOMMU_DEV_FEAT_IOPF);
407 		return flags;
408 	}
409 
410 	return flags | UACCE_DEV_SVA;
411 }
412 
413 static void uacce_disable_sva(struct uacce_device *uacce)
414 {
415 	if (!(uacce->flags & UACCE_DEV_SVA))
416 		return;
417 
418 	iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA);
419 	iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_IOPF);
420 }
421 
422 /**
423  * uacce_alloc() - alloc an accelerator
424  * @parent: pointer of uacce parent device
425  * @interface: pointer of uacce_interface for register
426  *
427  * Returns uacce pointer if success and ERR_PTR if not
428  * Need check returned negotiated uacce->flags
429  */
430 struct uacce_device *uacce_alloc(struct device *parent,
431 				 struct uacce_interface *interface)
432 {
433 	unsigned int flags = interface->flags;
434 	struct uacce_device *uacce;
435 	int ret;
436 
437 	uacce = kzalloc(sizeof(struct uacce_device), GFP_KERNEL);
438 	if (!uacce)
439 		return ERR_PTR(-ENOMEM);
440 
441 	flags = uacce_enable_sva(parent, flags);
442 
443 	uacce->parent = parent;
444 	uacce->flags = flags;
445 	uacce->ops = interface->ops;
446 
447 	ret = xa_alloc(&uacce_xa, &uacce->dev_id, uacce, xa_limit_32b,
448 		       GFP_KERNEL);
449 	if (ret < 0)
450 		goto err_with_uacce;
451 
452 	INIT_LIST_HEAD(&uacce->queues);
453 	mutex_init(&uacce->queues_lock);
454 	device_initialize(&uacce->dev);
455 	uacce->dev.devt = MKDEV(MAJOR(uacce_devt), uacce->dev_id);
456 	uacce->dev.class = uacce_class;
457 	uacce->dev.groups = uacce_dev_groups;
458 	uacce->dev.parent = uacce->parent;
459 	uacce->dev.release = uacce_release;
460 	dev_set_name(&uacce->dev, "%s-%d", interface->name, uacce->dev_id);
461 
462 	return uacce;
463 
464 err_with_uacce:
465 	uacce_disable_sva(uacce);
466 	kfree(uacce);
467 	return ERR_PTR(ret);
468 }
469 EXPORT_SYMBOL_GPL(uacce_alloc);
470 
471 /**
472  * uacce_register() - add the accelerator to cdev and export to user space
473  * @uacce: The initialized uacce device
474  *
475  * Return 0 if register succeeded, or an error.
476  */
477 int uacce_register(struct uacce_device *uacce)
478 {
479 	if (!uacce)
480 		return -ENODEV;
481 
482 	uacce->cdev = cdev_alloc();
483 	if (!uacce->cdev)
484 		return -ENOMEM;
485 
486 	uacce->cdev->ops = &uacce_fops;
487 	uacce->cdev->owner = THIS_MODULE;
488 
489 	return cdev_device_add(uacce->cdev, &uacce->dev);
490 }
491 EXPORT_SYMBOL_GPL(uacce_register);
492 
493 /**
494  * uacce_remove() - remove the accelerator
495  * @uacce: the accelerator to remove
496  */
497 void uacce_remove(struct uacce_device *uacce)
498 {
499 	struct uacce_queue *q, *next_q;
500 
501 	if (!uacce)
502 		return;
503 	/*
504 	 * unmap remaining mapping from user space, preventing user still
505 	 * access the mmaped area while parent device is already removed
506 	 */
507 	if (uacce->inode)
508 		unmap_mapping_range(uacce->inode->i_mapping, 0, 0, 1);
509 
510 	/* ensure no open queue remains */
511 	mutex_lock(&uacce->queues_lock);
512 	list_for_each_entry_safe(q, next_q, &uacce->queues, list) {
513 		uacce_put_queue(q);
514 		uacce_unbind_queue(q);
515 	}
516 	mutex_unlock(&uacce->queues_lock);
517 
518 	/* disable sva now since no opened queues */
519 	uacce_disable_sva(uacce);
520 
521 	if (uacce->cdev)
522 		cdev_device_del(uacce->cdev, &uacce->dev);
523 	xa_erase(&uacce_xa, uacce->dev_id);
524 	put_device(&uacce->dev);
525 }
526 EXPORT_SYMBOL_GPL(uacce_remove);
527 
528 static int __init uacce_init(void)
529 {
530 	int ret;
531 
532 	uacce_class = class_create(THIS_MODULE, UACCE_NAME);
533 	if (IS_ERR(uacce_class))
534 		return PTR_ERR(uacce_class);
535 
536 	ret = alloc_chrdev_region(&uacce_devt, 0, MINORMASK, UACCE_NAME);
537 	if (ret)
538 		class_destroy(uacce_class);
539 
540 	return ret;
541 }
542 
543 static __exit void uacce_exit(void)
544 {
545 	unregister_chrdev_region(uacce_devt, MINORMASK);
546 	class_destroy(uacce_class);
547 }
548 
549 subsys_initcall(uacce_init);
550 module_exit(uacce_exit);
551 
552 MODULE_LICENSE("GPL");
553 MODULE_AUTHOR("HiSilicon Tech. Co., Ltd.");
554 MODULE_DESCRIPTION("Accelerator interface for Userland applications");
555