xref: /openbmc/linux/drivers/misc/uacce/uacce.c (revision 3a35093a)
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 = 0;
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 /**
389  * uacce_alloc() - alloc an accelerator
390  * @parent: pointer of uacce parent device
391  * @interface: pointer of uacce_interface for register
392  *
393  * Returns uacce pointer if success and ERR_PTR if not
394  * Need check returned negotiated uacce->flags
395  */
396 struct uacce_device *uacce_alloc(struct device *parent,
397 				 struct uacce_interface *interface)
398 {
399 	unsigned int flags = interface->flags;
400 	struct uacce_device *uacce;
401 	int ret;
402 
403 	uacce = kzalloc(sizeof(struct uacce_device), GFP_KERNEL);
404 	if (!uacce)
405 		return ERR_PTR(-ENOMEM);
406 
407 	if (flags & UACCE_DEV_SVA) {
408 		ret = iommu_dev_enable_feature(parent, IOMMU_DEV_FEAT_SVA);
409 		if (ret)
410 			flags &= ~UACCE_DEV_SVA;
411 	}
412 
413 	uacce->parent = parent;
414 	uacce->flags = flags;
415 	uacce->ops = interface->ops;
416 
417 	ret = xa_alloc(&uacce_xa, &uacce->dev_id, uacce, xa_limit_32b,
418 		       GFP_KERNEL);
419 	if (ret < 0)
420 		goto err_with_uacce;
421 
422 	INIT_LIST_HEAD(&uacce->queues);
423 	mutex_init(&uacce->queues_lock);
424 	device_initialize(&uacce->dev);
425 	uacce->dev.devt = MKDEV(MAJOR(uacce_devt), uacce->dev_id);
426 	uacce->dev.class = uacce_class;
427 	uacce->dev.groups = uacce_dev_groups;
428 	uacce->dev.parent = uacce->parent;
429 	uacce->dev.release = uacce_release;
430 	dev_set_name(&uacce->dev, "%s-%d", interface->name, uacce->dev_id);
431 
432 	return uacce;
433 
434 err_with_uacce:
435 	if (flags & UACCE_DEV_SVA)
436 		iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA);
437 	kfree(uacce);
438 	return ERR_PTR(ret);
439 }
440 EXPORT_SYMBOL_GPL(uacce_alloc);
441 
442 /**
443  * uacce_register() - add the accelerator to cdev and export to user space
444  * @uacce: The initialized uacce device
445  *
446  * Return 0 if register succeeded, or an error.
447  */
448 int uacce_register(struct uacce_device *uacce)
449 {
450 	if (!uacce)
451 		return -ENODEV;
452 
453 	uacce->cdev = cdev_alloc();
454 	if (!uacce->cdev)
455 		return -ENOMEM;
456 
457 	uacce->cdev->ops = &uacce_fops;
458 	uacce->cdev->owner = THIS_MODULE;
459 
460 	return cdev_device_add(uacce->cdev, &uacce->dev);
461 }
462 EXPORT_SYMBOL_GPL(uacce_register);
463 
464 /**
465  * uacce_remove() - remove the accelerator
466  * @uacce: the accelerator to remove
467  */
468 void uacce_remove(struct uacce_device *uacce)
469 {
470 	struct uacce_queue *q, *next_q;
471 
472 	if (!uacce)
473 		return;
474 	/*
475 	 * unmap remaining mapping from user space, preventing user still
476 	 * access the mmaped area while parent device is already removed
477 	 */
478 	if (uacce->inode)
479 		unmap_mapping_range(uacce->inode->i_mapping, 0, 0, 1);
480 
481 	/* ensure no open queue remains */
482 	mutex_lock(&uacce->queues_lock);
483 	list_for_each_entry_safe(q, next_q, &uacce->queues, list) {
484 		uacce_put_queue(q);
485 		uacce_unbind_queue(q);
486 	}
487 	mutex_unlock(&uacce->queues_lock);
488 
489 	/* disable sva now since no opened queues */
490 	if (uacce->flags & UACCE_DEV_SVA)
491 		iommu_dev_disable_feature(uacce->parent, IOMMU_DEV_FEAT_SVA);
492 
493 	if (uacce->cdev)
494 		cdev_device_del(uacce->cdev, &uacce->dev);
495 	xa_erase(&uacce_xa, uacce->dev_id);
496 	put_device(&uacce->dev);
497 }
498 EXPORT_SYMBOL_GPL(uacce_remove);
499 
500 static int __init uacce_init(void)
501 {
502 	int ret;
503 
504 	uacce_class = class_create(THIS_MODULE, UACCE_NAME);
505 	if (IS_ERR(uacce_class))
506 		return PTR_ERR(uacce_class);
507 
508 	ret = alloc_chrdev_region(&uacce_devt, 0, MINORMASK, UACCE_NAME);
509 	if (ret)
510 		class_destroy(uacce_class);
511 
512 	return ret;
513 }
514 
515 static __exit void uacce_exit(void)
516 {
517 	unregister_chrdev_region(uacce_devt, MINORMASK);
518 	class_destroy(uacce_class);
519 }
520 
521 subsys_initcall(uacce_init);
522 module_exit(uacce_exit);
523 
524 MODULE_LICENSE("GPL");
525 MODULE_AUTHOR("HiSilicon Tech. Co., Ltd.");
526 MODULE_DESCRIPTION("Accelerator interface for Userland applications");
527