xref: /freebsd/sys/compat/linuxkpi/common/src/linux_compat.c (revision 2dd94b045e8c069c1a748d40d30d979e30e02fc9)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2018 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_stack.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/kernel.h>
39 #include <sys/sysctl.h>
40 #include <sys/proc.h>
41 #include <sys/sglist.h>
42 #include <sys/sleepqueue.h>
43 #include <sys/refcount.h>
44 #include <sys/lock.h>
45 #include <sys/mutex.h>
46 #include <sys/bus.h>
47 #include <sys/eventhandler.h>
48 #include <sys/fcntl.h>
49 #include <sys/file.h>
50 #include <sys/filio.h>
51 #include <sys/rwlock.h>
52 #include <sys/mman.h>
53 #include <sys/stack.h>
54 #include <sys/user.h>
55 
56 #include <vm/vm.h>
57 #include <vm/pmap.h>
58 #include <vm/vm_object.h>
59 #include <vm/vm_page.h>
60 #include <vm/vm_pager.h>
61 
62 #include <machine/stdarg.h>
63 
64 #if defined(__i386__) || defined(__amd64__)
65 #include <machine/md_var.h>
66 #endif
67 
68 #include <linux/kobject.h>
69 #include <linux/device.h>
70 #include <linux/slab.h>
71 #include <linux/module.h>
72 #include <linux/moduleparam.h>
73 #include <linux/cdev.h>
74 #include <linux/file.h>
75 #include <linux/sysfs.h>
76 #include <linux/mm.h>
77 #include <linux/io.h>
78 #include <linux/vmalloc.h>
79 #include <linux/netdevice.h>
80 #include <linux/timer.h>
81 #include <linux/interrupt.h>
82 #include <linux/uaccess.h>
83 #include <linux/list.h>
84 #include <linux/kthread.h>
85 #include <linux/kernel.h>
86 #include <linux/compat.h>
87 #include <linux/poll.h>
88 #include <linux/smp.h>
89 
90 #if defined(__i386__) || defined(__amd64__)
91 #include <asm/smp.h>
92 #endif
93 
94 SYSCTL_NODE(_compat, OID_AUTO, linuxkpi, CTLFLAG_RW, 0, "LinuxKPI parameters");
95 
96 int linuxkpi_debug;
97 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, debug, CTLFLAG_RWTUN,
98     &linuxkpi_debug, 0, "Set to enable pr_debug() prints. Clear to disable.");
99 
100 MALLOC_DEFINE(M_KMALLOC, "linux", "Linux kmalloc compat");
101 
102 #include <linux/rbtree.h>
103 /* Undo Linux compat changes. */
104 #undef RB_ROOT
105 #undef file
106 #undef cdev
107 #define	RB_ROOT(head)	(head)->rbh_root
108 
109 static void linux_cdev_deref(struct linux_cdev *ldev);
110 static struct vm_area_struct *linux_cdev_handle_find(void *handle);
111 
112 struct kobject linux_class_root;
113 struct device linux_root_device;
114 struct class linux_class_misc;
115 struct list_head pci_drivers;
116 struct list_head pci_devices;
117 spinlock_t pci_lock;
118 
119 unsigned long linux_timer_hz_mask;
120 
121 int
122 panic_cmp(struct rb_node *one, struct rb_node *two)
123 {
124 	panic("no cmp");
125 }
126 
127 RB_GENERATE(linux_root, rb_node, __entry, panic_cmp);
128 
129 int
130 kobject_set_name_vargs(struct kobject *kobj, const char *fmt, va_list args)
131 {
132 	va_list tmp_va;
133 	int len;
134 	char *old;
135 	char *name;
136 	char dummy;
137 
138 	old = kobj->name;
139 
140 	if (old && fmt == NULL)
141 		return (0);
142 
143 	/* compute length of string */
144 	va_copy(tmp_va, args);
145 	len = vsnprintf(&dummy, 0, fmt, tmp_va);
146 	va_end(tmp_va);
147 
148 	/* account for zero termination */
149 	len++;
150 
151 	/* check for error */
152 	if (len < 1)
153 		return (-EINVAL);
154 
155 	/* allocate memory for string */
156 	name = kzalloc(len, GFP_KERNEL);
157 	if (name == NULL)
158 		return (-ENOMEM);
159 	vsnprintf(name, len, fmt, args);
160 	kobj->name = name;
161 
162 	/* free old string */
163 	kfree(old);
164 
165 	/* filter new string */
166 	for (; *name != '\0'; name++)
167 		if (*name == '/')
168 			*name = '!';
169 	return (0);
170 }
171 
172 int
173 kobject_set_name(struct kobject *kobj, const char *fmt, ...)
174 {
175 	va_list args;
176 	int error;
177 
178 	va_start(args, fmt);
179 	error = kobject_set_name_vargs(kobj, fmt, args);
180 	va_end(args);
181 
182 	return (error);
183 }
184 
185 static int
186 kobject_add_complete(struct kobject *kobj, struct kobject *parent)
187 {
188 	const struct kobj_type *t;
189 	int error;
190 
191 	kobj->parent = parent;
192 	error = sysfs_create_dir(kobj);
193 	if (error == 0 && kobj->ktype && kobj->ktype->default_attrs) {
194 		struct attribute **attr;
195 		t = kobj->ktype;
196 
197 		for (attr = t->default_attrs; *attr != NULL; attr++) {
198 			error = sysfs_create_file(kobj, *attr);
199 			if (error)
200 				break;
201 		}
202 		if (error)
203 			sysfs_remove_dir(kobj);
204 
205 	}
206 	return (error);
207 }
208 
209 int
210 kobject_add(struct kobject *kobj, struct kobject *parent, const char *fmt, ...)
211 {
212 	va_list args;
213 	int error;
214 
215 	va_start(args, fmt);
216 	error = kobject_set_name_vargs(kobj, fmt, args);
217 	va_end(args);
218 	if (error)
219 		return (error);
220 
221 	return kobject_add_complete(kobj, parent);
222 }
223 
224 void
225 linux_kobject_release(struct kref *kref)
226 {
227 	struct kobject *kobj;
228 	char *name;
229 
230 	kobj = container_of(kref, struct kobject, kref);
231 	sysfs_remove_dir(kobj);
232 	name = kobj->name;
233 	if (kobj->ktype && kobj->ktype->release)
234 		kobj->ktype->release(kobj);
235 	kfree(name);
236 }
237 
238 static void
239 linux_kobject_kfree(struct kobject *kobj)
240 {
241 	kfree(kobj);
242 }
243 
244 static void
245 linux_kobject_kfree_name(struct kobject *kobj)
246 {
247 	if (kobj) {
248 		kfree(kobj->name);
249 	}
250 }
251 
252 const struct kobj_type linux_kfree_type = {
253 	.release = linux_kobject_kfree
254 };
255 
256 static void
257 linux_device_release(struct device *dev)
258 {
259 	pr_debug("linux_device_release: %s\n", dev_name(dev));
260 	kfree(dev);
261 }
262 
263 static ssize_t
264 linux_class_show(struct kobject *kobj, struct attribute *attr, char *buf)
265 {
266 	struct class_attribute *dattr;
267 	ssize_t error;
268 
269 	dattr = container_of(attr, struct class_attribute, attr);
270 	error = -EIO;
271 	if (dattr->show)
272 		error = dattr->show(container_of(kobj, struct class, kobj),
273 		    dattr, buf);
274 	return (error);
275 }
276 
277 static ssize_t
278 linux_class_store(struct kobject *kobj, struct attribute *attr, const char *buf,
279     size_t count)
280 {
281 	struct class_attribute *dattr;
282 	ssize_t error;
283 
284 	dattr = container_of(attr, struct class_attribute, attr);
285 	error = -EIO;
286 	if (dattr->store)
287 		error = dattr->store(container_of(kobj, struct class, kobj),
288 		    dattr, buf, count);
289 	return (error);
290 }
291 
292 static void
293 linux_class_release(struct kobject *kobj)
294 {
295 	struct class *class;
296 
297 	class = container_of(kobj, struct class, kobj);
298 	if (class->class_release)
299 		class->class_release(class);
300 }
301 
302 static const struct sysfs_ops linux_class_sysfs = {
303 	.show  = linux_class_show,
304 	.store = linux_class_store,
305 };
306 
307 const struct kobj_type linux_class_ktype = {
308 	.release = linux_class_release,
309 	.sysfs_ops = &linux_class_sysfs
310 };
311 
312 static void
313 linux_dev_release(struct kobject *kobj)
314 {
315 	struct device *dev;
316 
317 	dev = container_of(kobj, struct device, kobj);
318 	/* This is the precedence defined by linux. */
319 	if (dev->release)
320 		dev->release(dev);
321 	else if (dev->class && dev->class->dev_release)
322 		dev->class->dev_release(dev);
323 }
324 
325 static ssize_t
326 linux_dev_show(struct kobject *kobj, struct attribute *attr, char *buf)
327 {
328 	struct device_attribute *dattr;
329 	ssize_t error;
330 
331 	dattr = container_of(attr, struct device_attribute, attr);
332 	error = -EIO;
333 	if (dattr->show)
334 		error = dattr->show(container_of(kobj, struct device, kobj),
335 		    dattr, buf);
336 	return (error);
337 }
338 
339 static ssize_t
340 linux_dev_store(struct kobject *kobj, struct attribute *attr, const char *buf,
341     size_t count)
342 {
343 	struct device_attribute *dattr;
344 	ssize_t error;
345 
346 	dattr = container_of(attr, struct device_attribute, attr);
347 	error = -EIO;
348 	if (dattr->store)
349 		error = dattr->store(container_of(kobj, struct device, kobj),
350 		    dattr, buf, count);
351 	return (error);
352 }
353 
354 static const struct sysfs_ops linux_dev_sysfs = {
355 	.show  = linux_dev_show,
356 	.store = linux_dev_store,
357 };
358 
359 const struct kobj_type linux_dev_ktype = {
360 	.release = linux_dev_release,
361 	.sysfs_ops = &linux_dev_sysfs
362 };
363 
364 struct device *
365 device_create(struct class *class, struct device *parent, dev_t devt,
366     void *drvdata, const char *fmt, ...)
367 {
368 	struct device *dev;
369 	va_list args;
370 
371 	dev = kzalloc(sizeof(*dev), M_WAITOK);
372 	dev->parent = parent;
373 	dev->class = class;
374 	dev->devt = devt;
375 	dev->driver_data = drvdata;
376 	dev->release = linux_device_release;
377 	va_start(args, fmt);
378 	kobject_set_name_vargs(&dev->kobj, fmt, args);
379 	va_end(args);
380 	device_register(dev);
381 
382 	return (dev);
383 }
384 
385 int
386 kobject_init_and_add(struct kobject *kobj, const struct kobj_type *ktype,
387     struct kobject *parent, const char *fmt, ...)
388 {
389 	va_list args;
390 	int error;
391 
392 	kobject_init(kobj, ktype);
393 	kobj->ktype = ktype;
394 	kobj->parent = parent;
395 	kobj->name = NULL;
396 
397 	va_start(args, fmt);
398 	error = kobject_set_name_vargs(kobj, fmt, args);
399 	va_end(args);
400 	if (error)
401 		return (error);
402 	return kobject_add_complete(kobj, parent);
403 }
404 
405 static void
406 linux_kq_lock(void *arg)
407 {
408 	spinlock_t *s = arg;
409 
410 	spin_lock(s);
411 }
412 static void
413 linux_kq_unlock(void *arg)
414 {
415 	spinlock_t *s = arg;
416 
417 	spin_unlock(s);
418 }
419 
420 static void
421 linux_kq_lock_owned(void *arg)
422 {
423 #ifdef INVARIANTS
424 	spinlock_t *s = arg;
425 
426 	mtx_assert(&s->m, MA_OWNED);
427 #endif
428 }
429 
430 static void
431 linux_kq_lock_unowned(void *arg)
432 {
433 #ifdef INVARIANTS
434 	spinlock_t *s = arg;
435 
436 	mtx_assert(&s->m, MA_NOTOWNED);
437 #endif
438 }
439 
440 static void
441 linux_file_kqfilter_poll(struct linux_file *, int);
442 
443 struct linux_file *
444 linux_file_alloc(void)
445 {
446 	struct linux_file *filp;
447 
448 	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
449 
450 	/* set initial refcount */
451 	filp->f_count = 1;
452 
453 	/* setup fields needed by kqueue support */
454 	spin_lock_init(&filp->f_kqlock);
455 	knlist_init(&filp->f_selinfo.si_note, &filp->f_kqlock,
456 	    linux_kq_lock, linux_kq_unlock,
457 	    linux_kq_lock_owned, linux_kq_lock_unowned);
458 
459 	return (filp);
460 }
461 
462 void
463 linux_file_free(struct linux_file *filp)
464 {
465 	if (filp->_file == NULL) {
466 		if (filp->f_shmem != NULL)
467 			vm_object_deallocate(filp->f_shmem);
468 		kfree(filp);
469 	} else {
470 		/*
471 		 * The close method of the character device or file
472 		 * will free the linux_file structure:
473 		 */
474 		_fdrop(filp->_file, curthread);
475 	}
476 }
477 
478 static int
479 linux_cdev_pager_fault(vm_object_t vm_obj, vm_ooffset_t offset, int prot,
480     vm_page_t *mres)
481 {
482 	struct vm_area_struct *vmap;
483 
484 	vmap = linux_cdev_handle_find(vm_obj->handle);
485 
486 	MPASS(vmap != NULL);
487 	MPASS(vmap->vm_private_data == vm_obj->handle);
488 
489 	if (likely(vmap->vm_ops != NULL && offset < vmap->vm_len)) {
490 		vm_paddr_t paddr = IDX_TO_OFF(vmap->vm_pfn) + offset;
491 		vm_page_t page;
492 
493 		if (((*mres)->flags & PG_FICTITIOUS) != 0) {
494 			/*
495 			 * If the passed in result page is a fake
496 			 * page, update it with the new physical
497 			 * address.
498 			 */
499 			page = *mres;
500 			vm_page_updatefake(page, paddr, vm_obj->memattr);
501 		} else {
502 			/*
503 			 * Replace the passed in "mres" page with our
504 			 * own fake page and free up the all of the
505 			 * original pages.
506 			 */
507 			VM_OBJECT_WUNLOCK(vm_obj);
508 			page = vm_page_getfake(paddr, vm_obj->memattr);
509 			VM_OBJECT_WLOCK(vm_obj);
510 
511 			vm_page_replace(page, vm_obj, (*mres)->pindex, *mres);
512 			*mres = page;
513 		}
514 		vm_page_valid(page);
515 		return (VM_PAGER_OK);
516 	}
517 	return (VM_PAGER_FAIL);
518 }
519 
520 static int
521 linux_cdev_pager_populate(vm_object_t vm_obj, vm_pindex_t pidx, int fault_type,
522     vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
523 {
524 	struct vm_area_struct *vmap;
525 	int err;
526 
527 	linux_set_current(curthread);
528 
529 	/* get VM area structure */
530 	vmap = linux_cdev_handle_find(vm_obj->handle);
531 	MPASS(vmap != NULL);
532 	MPASS(vmap->vm_private_data == vm_obj->handle);
533 
534 	VM_OBJECT_WUNLOCK(vm_obj);
535 
536 	down_write(&vmap->vm_mm->mmap_sem);
537 	if (unlikely(vmap->vm_ops == NULL)) {
538 		err = VM_FAULT_SIGBUS;
539 	} else {
540 		struct vm_fault vmf;
541 
542 		/* fill out VM fault structure */
543 		vmf.virtual_address = (void *)(uintptr_t)IDX_TO_OFF(pidx);
544 		vmf.flags = (fault_type & VM_PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
545 		vmf.pgoff = 0;
546 		vmf.page = NULL;
547 		vmf.vma = vmap;
548 
549 		vmap->vm_pfn_count = 0;
550 		vmap->vm_pfn_pcount = &vmap->vm_pfn_count;
551 		vmap->vm_obj = vm_obj;
552 
553 		err = vmap->vm_ops->fault(vmap, &vmf);
554 
555 		while (vmap->vm_pfn_count == 0 && err == VM_FAULT_NOPAGE) {
556 			kern_yield(PRI_USER);
557 			err = vmap->vm_ops->fault(vmap, &vmf);
558 		}
559 	}
560 
561 	/* translate return code */
562 	switch (err) {
563 	case VM_FAULT_OOM:
564 		err = VM_PAGER_AGAIN;
565 		break;
566 	case VM_FAULT_SIGBUS:
567 		err = VM_PAGER_BAD;
568 		break;
569 	case VM_FAULT_NOPAGE:
570 		/*
571 		 * By contract the fault handler will return having
572 		 * busied all the pages itself. If pidx is already
573 		 * found in the object, it will simply xbusy the first
574 		 * page and return with vm_pfn_count set to 1.
575 		 */
576 		*first = vmap->vm_pfn_first;
577 		*last = *first + vmap->vm_pfn_count - 1;
578 		err = VM_PAGER_OK;
579 		break;
580 	default:
581 		err = VM_PAGER_ERROR;
582 		break;
583 	}
584 	up_write(&vmap->vm_mm->mmap_sem);
585 	VM_OBJECT_WLOCK(vm_obj);
586 	return (err);
587 }
588 
589 static struct rwlock linux_vma_lock;
590 static TAILQ_HEAD(, vm_area_struct) linux_vma_head =
591     TAILQ_HEAD_INITIALIZER(linux_vma_head);
592 
593 static void
594 linux_cdev_handle_free(struct vm_area_struct *vmap)
595 {
596 	/* Drop reference on vm_file */
597 	if (vmap->vm_file != NULL)
598 		fput(vmap->vm_file);
599 
600 	/* Drop reference on mm_struct */
601 	mmput(vmap->vm_mm);
602 
603 	kfree(vmap);
604 }
605 
606 static void
607 linux_cdev_handle_remove(struct vm_area_struct *vmap)
608 {
609 	rw_wlock(&linux_vma_lock);
610 	TAILQ_REMOVE(&linux_vma_head, vmap, vm_entry);
611 	rw_wunlock(&linux_vma_lock);
612 }
613 
614 static struct vm_area_struct *
615 linux_cdev_handle_find(void *handle)
616 {
617 	struct vm_area_struct *vmap;
618 
619 	rw_rlock(&linux_vma_lock);
620 	TAILQ_FOREACH(vmap, &linux_vma_head, vm_entry) {
621 		if (vmap->vm_private_data == handle)
622 			break;
623 	}
624 	rw_runlock(&linux_vma_lock);
625 	return (vmap);
626 }
627 
628 static int
629 linux_cdev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
630 		      vm_ooffset_t foff, struct ucred *cred, u_short *color)
631 {
632 
633 	MPASS(linux_cdev_handle_find(handle) != NULL);
634 	*color = 0;
635 	return (0);
636 }
637 
638 static void
639 linux_cdev_pager_dtor(void *handle)
640 {
641 	const struct vm_operations_struct *vm_ops;
642 	struct vm_area_struct *vmap;
643 
644 	vmap = linux_cdev_handle_find(handle);
645 	MPASS(vmap != NULL);
646 
647 	/*
648 	 * Remove handle before calling close operation to prevent
649 	 * other threads from reusing the handle pointer.
650 	 */
651 	linux_cdev_handle_remove(vmap);
652 
653 	down_write(&vmap->vm_mm->mmap_sem);
654 	vm_ops = vmap->vm_ops;
655 	if (likely(vm_ops != NULL))
656 		vm_ops->close(vmap);
657 	up_write(&vmap->vm_mm->mmap_sem);
658 
659 	linux_cdev_handle_free(vmap);
660 }
661 
662 static struct cdev_pager_ops linux_cdev_pager_ops[2] = {
663   {
664 	/* OBJT_MGTDEVICE */
665 	.cdev_pg_populate	= linux_cdev_pager_populate,
666 	.cdev_pg_ctor	= linux_cdev_pager_ctor,
667 	.cdev_pg_dtor	= linux_cdev_pager_dtor
668   },
669   {
670 	/* OBJT_DEVICE */
671 	.cdev_pg_fault	= linux_cdev_pager_fault,
672 	.cdev_pg_ctor	= linux_cdev_pager_ctor,
673 	.cdev_pg_dtor	= linux_cdev_pager_dtor
674   },
675 };
676 
677 int
678 zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
679     unsigned long size)
680 {
681 	vm_object_t obj;
682 	vm_page_t m;
683 
684 	obj = vma->vm_obj;
685 	if (obj == NULL || (obj->flags & OBJ_UNMANAGED) != 0)
686 		return (-ENOTSUP);
687 	VM_OBJECT_RLOCK(obj);
688 	for (m = vm_page_find_least(obj, OFF_TO_IDX(address));
689 	    m != NULL && m->pindex < OFF_TO_IDX(address + size);
690 	    m = TAILQ_NEXT(m, listq))
691 		pmap_remove_all(m);
692 	VM_OBJECT_RUNLOCK(obj);
693 	return (0);
694 }
695 
696 static struct file_operations dummy_ldev_ops = {
697 	/* XXXKIB */
698 };
699 
700 static struct linux_cdev dummy_ldev = {
701 	.ops = &dummy_ldev_ops,
702 };
703 
704 #define	LDEV_SI_DTR	0x0001
705 #define	LDEV_SI_REF	0x0002
706 
707 static void
708 linux_get_fop(struct linux_file *filp, const struct file_operations **fop,
709     struct linux_cdev **dev)
710 {
711 	struct linux_cdev *ldev;
712 	u_int siref;
713 
714 	ldev = filp->f_cdev;
715 	*fop = filp->f_op;
716 	if (ldev != NULL) {
717 		for (siref = ldev->siref;;) {
718 			if ((siref & LDEV_SI_DTR) != 0) {
719 				ldev = &dummy_ldev;
720 				siref = ldev->siref;
721 				*fop = ldev->ops;
722 				MPASS((ldev->siref & LDEV_SI_DTR) == 0);
723 			} else if (atomic_fcmpset_int(&ldev->siref, &siref,
724 			    siref + LDEV_SI_REF)) {
725 				break;
726 			}
727 		}
728 	}
729 	*dev = ldev;
730 }
731 
732 static void
733 linux_drop_fop(struct linux_cdev *ldev)
734 {
735 
736 	if (ldev == NULL)
737 		return;
738 	MPASS((ldev->siref & ~LDEV_SI_DTR) != 0);
739 	atomic_subtract_int(&ldev->siref, LDEV_SI_REF);
740 }
741 
742 #define	OPW(fp,td,code) ({			\
743 	struct file *__fpop;			\
744 	__typeof(code) __retval;		\
745 						\
746 	__fpop = (td)->td_fpop;			\
747 	(td)->td_fpop = (fp);			\
748 	__retval = (code);			\
749 	(td)->td_fpop = __fpop;			\
750 	__retval;				\
751 })
752 
753 static int
754 linux_dev_fdopen(struct cdev *dev, int fflags, struct thread *td,
755     struct file *file)
756 {
757 	struct linux_cdev *ldev;
758 	struct linux_file *filp;
759 	const struct file_operations *fop;
760 	int error;
761 
762 	ldev = dev->si_drv1;
763 
764 	filp = linux_file_alloc();
765 	filp->f_dentry = &filp->f_dentry_store;
766 	filp->f_op = ldev->ops;
767 	filp->f_mode = file->f_flag;
768 	filp->f_flags = file->f_flag;
769 	filp->f_vnode = file->f_vnode;
770 	filp->_file = file;
771 	refcount_acquire(&ldev->refs);
772 	filp->f_cdev = ldev;
773 
774 	linux_set_current(td);
775 	linux_get_fop(filp, &fop, &ldev);
776 
777 	if (fop->open != NULL) {
778 		error = -fop->open(file->f_vnode, filp);
779 		if (error != 0) {
780 			linux_drop_fop(ldev);
781 			linux_cdev_deref(filp->f_cdev);
782 			kfree(filp);
783 			return (error);
784 		}
785 	}
786 
787 	/* hold on to the vnode - used for fstat() */
788 	vhold(filp->f_vnode);
789 
790 	/* release the file from devfs */
791 	finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
792 	linux_drop_fop(ldev);
793 	return (ENXIO);
794 }
795 
796 #define	LINUX_IOCTL_MIN_PTR 0x10000UL
797 #define	LINUX_IOCTL_MAX_PTR (LINUX_IOCTL_MIN_PTR + IOCPARM_MAX)
798 
799 static inline int
800 linux_remap_address(void **uaddr, size_t len)
801 {
802 	uintptr_t uaddr_val = (uintptr_t)(*uaddr);
803 
804 	if (unlikely(uaddr_val >= LINUX_IOCTL_MIN_PTR &&
805 	    uaddr_val < LINUX_IOCTL_MAX_PTR)) {
806 		struct task_struct *pts = current;
807 		if (pts == NULL) {
808 			*uaddr = NULL;
809 			return (1);
810 		}
811 
812 		/* compute data offset */
813 		uaddr_val -= LINUX_IOCTL_MIN_PTR;
814 
815 		/* check that length is within bounds */
816 		if ((len > IOCPARM_MAX) ||
817 		    (uaddr_val + len) > pts->bsd_ioctl_len) {
818 			*uaddr = NULL;
819 			return (1);
820 		}
821 
822 		/* re-add kernel buffer address */
823 		uaddr_val += (uintptr_t)pts->bsd_ioctl_data;
824 
825 		/* update address location */
826 		*uaddr = (void *)uaddr_val;
827 		return (1);
828 	}
829 	return (0);
830 }
831 
832 int
833 linux_copyin(const void *uaddr, void *kaddr, size_t len)
834 {
835 	if (linux_remap_address(__DECONST(void **, &uaddr), len)) {
836 		if (uaddr == NULL)
837 			return (-EFAULT);
838 		memcpy(kaddr, uaddr, len);
839 		return (0);
840 	}
841 	return (-copyin(uaddr, kaddr, len));
842 }
843 
844 int
845 linux_copyout(const void *kaddr, void *uaddr, size_t len)
846 {
847 	if (linux_remap_address(&uaddr, len)) {
848 		if (uaddr == NULL)
849 			return (-EFAULT);
850 		memcpy(uaddr, kaddr, len);
851 		return (0);
852 	}
853 	return (-copyout(kaddr, uaddr, len));
854 }
855 
856 size_t
857 linux_clear_user(void *_uaddr, size_t _len)
858 {
859 	uint8_t *uaddr = _uaddr;
860 	size_t len = _len;
861 
862 	/* make sure uaddr is aligned before going into the fast loop */
863 	while (((uintptr_t)uaddr & 7) != 0 && len > 7) {
864 		if (subyte(uaddr, 0))
865 			return (_len);
866 		uaddr++;
867 		len--;
868 	}
869 
870 	/* zero 8 bytes at a time */
871 	while (len > 7) {
872 #ifdef __LP64__
873 		if (suword64(uaddr, 0))
874 			return (_len);
875 #else
876 		if (suword32(uaddr, 0))
877 			return (_len);
878 		if (suword32(uaddr + 4, 0))
879 			return (_len);
880 #endif
881 		uaddr += 8;
882 		len -= 8;
883 	}
884 
885 	/* zero fill end, if any */
886 	while (len > 0) {
887 		if (subyte(uaddr, 0))
888 			return (_len);
889 		uaddr++;
890 		len--;
891 	}
892 	return (0);
893 }
894 
895 int
896 linux_access_ok(const void *uaddr, size_t len)
897 {
898 	uintptr_t saddr;
899 	uintptr_t eaddr;
900 
901 	/* get start and end address */
902 	saddr = (uintptr_t)uaddr;
903 	eaddr = (uintptr_t)uaddr + len;
904 
905 	/* verify addresses are valid for userspace */
906 	return ((saddr == eaddr) ||
907 	    (eaddr > saddr && eaddr <= VM_MAXUSER_ADDRESS));
908 }
909 
910 /*
911  * This function should return either EINTR or ERESTART depending on
912  * the signal type sent to this thread:
913  */
914 static int
915 linux_get_error(struct task_struct *task, int error)
916 {
917 	/* check for signal type interrupt code */
918 	if (error == EINTR || error == ERESTARTSYS || error == ERESTART) {
919 		error = -linux_schedule_get_interrupt_value(task);
920 		if (error == 0)
921 			error = EINTR;
922 	}
923 	return (error);
924 }
925 
926 static int
927 linux_file_ioctl_sub(struct file *fp, struct linux_file *filp,
928     const struct file_operations *fop, u_long cmd, caddr_t data,
929     struct thread *td)
930 {
931 	struct task_struct *task = current;
932 	unsigned size;
933 	int error;
934 
935 	size = IOCPARM_LEN(cmd);
936 	/* refer to logic in sys_ioctl() */
937 	if (size > 0) {
938 		/*
939 		 * Setup hint for linux_copyin() and linux_copyout().
940 		 *
941 		 * Background: Linux code expects a user-space address
942 		 * while FreeBSD supplies a kernel-space address.
943 		 */
944 		task->bsd_ioctl_data = data;
945 		task->bsd_ioctl_len = size;
946 		data = (void *)LINUX_IOCTL_MIN_PTR;
947 	} else {
948 		/* fetch user-space pointer */
949 		data = *(void **)data;
950 	}
951 #if defined(__amd64__)
952 	if (td->td_proc->p_elf_machine == EM_386) {
953 		/* try the compat IOCTL handler first */
954 		if (fop->compat_ioctl != NULL) {
955 			error = -OPW(fp, td, fop->compat_ioctl(filp,
956 			    cmd, (u_long)data));
957 		} else {
958 			error = ENOTTY;
959 		}
960 
961 		/* fallback to the regular IOCTL handler, if any */
962 		if (error == ENOTTY && fop->unlocked_ioctl != NULL) {
963 			error = -OPW(fp, td, fop->unlocked_ioctl(filp,
964 			    cmd, (u_long)data));
965 		}
966 	} else
967 #endif
968 	{
969 		if (fop->unlocked_ioctl != NULL) {
970 			error = -OPW(fp, td, fop->unlocked_ioctl(filp,
971 			    cmd, (u_long)data));
972 		} else {
973 			error = ENOTTY;
974 		}
975 	}
976 	if (size > 0) {
977 		task->bsd_ioctl_data = NULL;
978 		task->bsd_ioctl_len = 0;
979 	}
980 
981 	if (error == EWOULDBLOCK) {
982 		/* update kqfilter status, if any */
983 		linux_file_kqfilter_poll(filp,
984 		    LINUX_KQ_FLAG_HAS_READ | LINUX_KQ_FLAG_HAS_WRITE);
985 	} else {
986 		error = linux_get_error(task, error);
987 	}
988 	return (error);
989 }
990 
991 #define	LINUX_POLL_TABLE_NORMAL ((poll_table *)1)
992 
993 /*
994  * This function atomically updates the poll wakeup state and returns
995  * the previous state at the time of update.
996  */
997 static uint8_t
998 linux_poll_wakeup_state(atomic_t *v, const uint8_t *pstate)
999 {
1000 	int c, old;
1001 
1002 	c = v->counter;
1003 
1004 	while ((old = atomic_cmpxchg(v, c, pstate[c])) != c)
1005 		c = old;
1006 
1007 	return (c);
1008 }
1009 
1010 
1011 static int
1012 linux_poll_wakeup_callback(wait_queue_t *wq, unsigned int wq_state, int flags, void *key)
1013 {
1014 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1015 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_INIT, /* NOP */
1016 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_NOT_READY, /* NOP */
1017 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_READY,
1018 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_READY, /* NOP */
1019 	};
1020 	struct linux_file *filp = container_of(wq, struct linux_file, f_wait_queue.wq);
1021 
1022 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1023 	case LINUX_FWQ_STATE_QUEUED:
1024 		linux_poll_wakeup(filp);
1025 		return (1);
1026 	default:
1027 		return (0);
1028 	}
1029 }
1030 
1031 void
1032 linux_poll_wait(struct linux_file *filp, wait_queue_head_t *wqh, poll_table *p)
1033 {
1034 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1035 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_NOT_READY,
1036 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_NOT_READY, /* NOP */
1037 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_QUEUED, /* NOP */
1038 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_QUEUED,
1039 	};
1040 
1041 	/* check if we are called inside the select system call */
1042 	if (p == LINUX_POLL_TABLE_NORMAL)
1043 		selrecord(curthread, &filp->f_selinfo);
1044 
1045 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1046 	case LINUX_FWQ_STATE_INIT:
1047 		/* NOTE: file handles can only belong to one wait-queue */
1048 		filp->f_wait_queue.wqh = wqh;
1049 		filp->f_wait_queue.wq.func = &linux_poll_wakeup_callback;
1050 		add_wait_queue(wqh, &filp->f_wait_queue.wq);
1051 		atomic_set(&filp->f_wait_queue.state, LINUX_FWQ_STATE_QUEUED);
1052 		break;
1053 	default:
1054 		break;
1055 	}
1056 }
1057 
1058 static void
1059 linux_poll_wait_dequeue(struct linux_file *filp)
1060 {
1061 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1062 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_INIT,	/* NOP */
1063 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_INIT,
1064 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_INIT,
1065 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_INIT,
1066 	};
1067 
1068 	seldrain(&filp->f_selinfo);
1069 
1070 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1071 	case LINUX_FWQ_STATE_NOT_READY:
1072 	case LINUX_FWQ_STATE_QUEUED:
1073 	case LINUX_FWQ_STATE_READY:
1074 		remove_wait_queue(filp->f_wait_queue.wqh, &filp->f_wait_queue.wq);
1075 		break;
1076 	default:
1077 		break;
1078 	}
1079 }
1080 
1081 void
1082 linux_poll_wakeup(struct linux_file *filp)
1083 {
1084 	/* this function should be NULL-safe */
1085 	if (filp == NULL)
1086 		return;
1087 
1088 	selwakeup(&filp->f_selinfo);
1089 
1090 	spin_lock(&filp->f_kqlock);
1091 	filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ |
1092 	    LINUX_KQ_FLAG_NEED_WRITE;
1093 
1094 	/* make sure the "knote" gets woken up */
1095 	KNOTE_LOCKED(&filp->f_selinfo.si_note, 1);
1096 	spin_unlock(&filp->f_kqlock);
1097 }
1098 
1099 static void
1100 linux_file_kqfilter_detach(struct knote *kn)
1101 {
1102 	struct linux_file *filp = kn->kn_hook;
1103 
1104 	spin_lock(&filp->f_kqlock);
1105 	knlist_remove(&filp->f_selinfo.si_note, kn, 1);
1106 	spin_unlock(&filp->f_kqlock);
1107 }
1108 
1109 static int
1110 linux_file_kqfilter_read_event(struct knote *kn, long hint)
1111 {
1112 	struct linux_file *filp = kn->kn_hook;
1113 
1114 	mtx_assert(&filp->f_kqlock.m, MA_OWNED);
1115 
1116 	return ((filp->f_kqflags & LINUX_KQ_FLAG_NEED_READ) ? 1 : 0);
1117 }
1118 
1119 static int
1120 linux_file_kqfilter_write_event(struct knote *kn, long hint)
1121 {
1122 	struct linux_file *filp = kn->kn_hook;
1123 
1124 	mtx_assert(&filp->f_kqlock.m, MA_OWNED);
1125 
1126 	return ((filp->f_kqflags & LINUX_KQ_FLAG_NEED_WRITE) ? 1 : 0);
1127 }
1128 
1129 static struct filterops linux_dev_kqfiltops_read = {
1130 	.f_isfd = 1,
1131 	.f_detach = linux_file_kqfilter_detach,
1132 	.f_event = linux_file_kqfilter_read_event,
1133 };
1134 
1135 static struct filterops linux_dev_kqfiltops_write = {
1136 	.f_isfd = 1,
1137 	.f_detach = linux_file_kqfilter_detach,
1138 	.f_event = linux_file_kqfilter_write_event,
1139 };
1140 
1141 static void
1142 linux_file_kqfilter_poll(struct linux_file *filp, int kqflags)
1143 {
1144 	struct thread *td;
1145 	const struct file_operations *fop;
1146 	struct linux_cdev *ldev;
1147 	int temp;
1148 
1149 	if ((filp->f_kqflags & kqflags) == 0)
1150 		return;
1151 
1152 	td = curthread;
1153 
1154 	linux_get_fop(filp, &fop, &ldev);
1155 	/* get the latest polling state */
1156 	temp = OPW(filp->_file, td, fop->poll(filp, NULL));
1157 	linux_drop_fop(ldev);
1158 
1159 	spin_lock(&filp->f_kqlock);
1160 	/* clear kqflags */
1161 	filp->f_kqflags &= ~(LINUX_KQ_FLAG_NEED_READ |
1162 	    LINUX_KQ_FLAG_NEED_WRITE);
1163 	/* update kqflags */
1164 	if ((temp & (POLLIN | POLLOUT)) != 0) {
1165 		if ((temp & POLLIN) != 0)
1166 			filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ;
1167 		if ((temp & POLLOUT) != 0)
1168 			filp->f_kqflags |= LINUX_KQ_FLAG_NEED_WRITE;
1169 
1170 		/* make sure the "knote" gets woken up */
1171 		KNOTE_LOCKED(&filp->f_selinfo.si_note, 0);
1172 	}
1173 	spin_unlock(&filp->f_kqlock);
1174 }
1175 
1176 static int
1177 linux_file_kqfilter(struct file *file, struct knote *kn)
1178 {
1179 	struct linux_file *filp;
1180 	struct thread *td;
1181 	int error;
1182 
1183 	td = curthread;
1184 	filp = (struct linux_file *)file->f_data;
1185 	filp->f_flags = file->f_flag;
1186 	if (filp->f_op->poll == NULL)
1187 		return (EINVAL);
1188 
1189 	spin_lock(&filp->f_kqlock);
1190 	switch (kn->kn_filter) {
1191 	case EVFILT_READ:
1192 		filp->f_kqflags |= LINUX_KQ_FLAG_HAS_READ;
1193 		kn->kn_fop = &linux_dev_kqfiltops_read;
1194 		kn->kn_hook = filp;
1195 		knlist_add(&filp->f_selinfo.si_note, kn, 1);
1196 		error = 0;
1197 		break;
1198 	case EVFILT_WRITE:
1199 		filp->f_kqflags |= LINUX_KQ_FLAG_HAS_WRITE;
1200 		kn->kn_fop = &linux_dev_kqfiltops_write;
1201 		kn->kn_hook = filp;
1202 		knlist_add(&filp->f_selinfo.si_note, kn, 1);
1203 		error = 0;
1204 		break;
1205 	default:
1206 		error = EINVAL;
1207 		break;
1208 	}
1209 	spin_unlock(&filp->f_kqlock);
1210 
1211 	if (error == 0) {
1212 		linux_set_current(td);
1213 
1214 		/* update kqfilter status, if any */
1215 		linux_file_kqfilter_poll(filp,
1216 		    LINUX_KQ_FLAG_HAS_READ | LINUX_KQ_FLAG_HAS_WRITE);
1217 	}
1218 	return (error);
1219 }
1220 
1221 static int
1222 linux_file_mmap_single(struct file *fp, const struct file_operations *fop,
1223     vm_ooffset_t *offset, vm_size_t size, struct vm_object **object,
1224     int nprot, struct thread *td)
1225 {
1226 	struct task_struct *task;
1227 	struct vm_area_struct *vmap;
1228 	struct mm_struct *mm;
1229 	struct linux_file *filp;
1230 	vm_memattr_t attr;
1231 	int error;
1232 
1233 	filp = (struct linux_file *)fp->f_data;
1234 	filp->f_flags = fp->f_flag;
1235 
1236 	if (fop->mmap == NULL)
1237 		return (EOPNOTSUPP);
1238 
1239 	linux_set_current(td);
1240 
1241 	/*
1242 	 * The same VM object might be shared by multiple processes
1243 	 * and the mm_struct is usually freed when a process exits.
1244 	 *
1245 	 * The atomic reference below makes sure the mm_struct is
1246 	 * available as long as the vmap is in the linux_vma_head.
1247 	 */
1248 	task = current;
1249 	mm = task->mm;
1250 	if (atomic_inc_not_zero(&mm->mm_users) == 0)
1251 		return (EINVAL);
1252 
1253 	vmap = kzalloc(sizeof(*vmap), GFP_KERNEL);
1254 	vmap->vm_start = 0;
1255 	vmap->vm_end = size;
1256 	vmap->vm_pgoff = *offset / PAGE_SIZE;
1257 	vmap->vm_pfn = 0;
1258 	vmap->vm_flags = vmap->vm_page_prot = (nprot & VM_PROT_ALL);
1259 	vmap->vm_ops = NULL;
1260 	vmap->vm_file = get_file(filp);
1261 	vmap->vm_mm = mm;
1262 
1263 	if (unlikely(down_write_killable(&vmap->vm_mm->mmap_sem))) {
1264 		error = linux_get_error(task, EINTR);
1265 	} else {
1266 		error = -OPW(fp, td, fop->mmap(filp, vmap));
1267 		error = linux_get_error(task, error);
1268 		up_write(&vmap->vm_mm->mmap_sem);
1269 	}
1270 
1271 	if (error != 0) {
1272 		linux_cdev_handle_free(vmap);
1273 		return (error);
1274 	}
1275 
1276 	attr = pgprot2cachemode(vmap->vm_page_prot);
1277 
1278 	if (vmap->vm_ops != NULL) {
1279 		struct vm_area_struct *ptr;
1280 		void *vm_private_data;
1281 		bool vm_no_fault;
1282 
1283 		if (vmap->vm_ops->open == NULL ||
1284 		    vmap->vm_ops->close == NULL ||
1285 		    vmap->vm_private_data == NULL) {
1286 			/* free allocated VM area struct */
1287 			linux_cdev_handle_free(vmap);
1288 			return (EINVAL);
1289 		}
1290 
1291 		vm_private_data = vmap->vm_private_data;
1292 
1293 		rw_wlock(&linux_vma_lock);
1294 		TAILQ_FOREACH(ptr, &linux_vma_head, vm_entry) {
1295 			if (ptr->vm_private_data == vm_private_data)
1296 				break;
1297 		}
1298 		/* check if there is an existing VM area struct */
1299 		if (ptr != NULL) {
1300 			/* check if the VM area structure is invalid */
1301 			if (ptr->vm_ops == NULL ||
1302 			    ptr->vm_ops->open == NULL ||
1303 			    ptr->vm_ops->close == NULL) {
1304 				error = ESTALE;
1305 				vm_no_fault = 1;
1306 			} else {
1307 				error = EEXIST;
1308 				vm_no_fault = (ptr->vm_ops->fault == NULL);
1309 			}
1310 		} else {
1311 			/* insert VM area structure into list */
1312 			TAILQ_INSERT_TAIL(&linux_vma_head, vmap, vm_entry);
1313 			error = 0;
1314 			vm_no_fault = (vmap->vm_ops->fault == NULL);
1315 		}
1316 		rw_wunlock(&linux_vma_lock);
1317 
1318 		if (error != 0) {
1319 			/* free allocated VM area struct */
1320 			linux_cdev_handle_free(vmap);
1321 			/* check for stale VM area struct */
1322 			if (error != EEXIST)
1323 				return (error);
1324 		}
1325 
1326 		/* check if there is no fault handler */
1327 		if (vm_no_fault) {
1328 			*object = cdev_pager_allocate(vm_private_data, OBJT_DEVICE,
1329 			    &linux_cdev_pager_ops[1], size, nprot, *offset,
1330 			    td->td_ucred);
1331 		} else {
1332 			*object = cdev_pager_allocate(vm_private_data, OBJT_MGTDEVICE,
1333 			    &linux_cdev_pager_ops[0], size, nprot, *offset,
1334 			    td->td_ucred);
1335 		}
1336 
1337 		/* check if allocating the VM object failed */
1338 		if (*object == NULL) {
1339 			if (error == 0) {
1340 				/* remove VM area struct from list */
1341 				linux_cdev_handle_remove(vmap);
1342 				/* free allocated VM area struct */
1343 				linux_cdev_handle_free(vmap);
1344 			}
1345 			return (EINVAL);
1346 		}
1347 	} else {
1348 		struct sglist *sg;
1349 
1350 		sg = sglist_alloc(1, M_WAITOK);
1351 		sglist_append_phys(sg,
1352 		    (vm_paddr_t)vmap->vm_pfn << PAGE_SHIFT, vmap->vm_len);
1353 
1354 		*object = vm_pager_allocate(OBJT_SG, sg, vmap->vm_len,
1355 		    nprot, 0, td->td_ucred);
1356 
1357 		linux_cdev_handle_free(vmap);
1358 
1359 		if (*object == NULL) {
1360 			sglist_free(sg);
1361 			return (EINVAL);
1362 		}
1363 	}
1364 
1365 	if (attr != VM_MEMATTR_DEFAULT) {
1366 		VM_OBJECT_WLOCK(*object);
1367 		vm_object_set_memattr(*object, attr);
1368 		VM_OBJECT_WUNLOCK(*object);
1369 	}
1370 	*offset = 0;
1371 	return (0);
1372 }
1373 
1374 struct cdevsw linuxcdevsw = {
1375 	.d_version = D_VERSION,
1376 	.d_fdopen = linux_dev_fdopen,
1377 	.d_name = "lkpidev",
1378 };
1379 
1380 static int
1381 linux_file_read(struct file *file, struct uio *uio, struct ucred *active_cred,
1382     int flags, struct thread *td)
1383 {
1384 	struct linux_file *filp;
1385 	const struct file_operations *fop;
1386 	struct linux_cdev *ldev;
1387 	ssize_t bytes;
1388 	int error;
1389 
1390 	error = 0;
1391 	filp = (struct linux_file *)file->f_data;
1392 	filp->f_flags = file->f_flag;
1393 	/* XXX no support for I/O vectors currently */
1394 	if (uio->uio_iovcnt != 1)
1395 		return (EOPNOTSUPP);
1396 	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1397 		return (EINVAL);
1398 	linux_set_current(td);
1399 	linux_get_fop(filp, &fop, &ldev);
1400 	if (fop->read != NULL) {
1401 		bytes = OPW(file, td, fop->read(filp,
1402 		    uio->uio_iov->iov_base,
1403 		    uio->uio_iov->iov_len, &uio->uio_offset));
1404 		if (bytes >= 0) {
1405 			uio->uio_iov->iov_base =
1406 			    ((uint8_t *)uio->uio_iov->iov_base) + bytes;
1407 			uio->uio_iov->iov_len -= bytes;
1408 			uio->uio_resid -= bytes;
1409 		} else {
1410 			error = linux_get_error(current, -bytes);
1411 		}
1412 	} else
1413 		error = ENXIO;
1414 
1415 	/* update kqfilter status, if any */
1416 	linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_READ);
1417 	linux_drop_fop(ldev);
1418 
1419 	return (error);
1420 }
1421 
1422 static int
1423 linux_file_write(struct file *file, struct uio *uio, struct ucred *active_cred,
1424     int flags, struct thread *td)
1425 {
1426 	struct linux_file *filp;
1427 	const struct file_operations *fop;
1428 	struct linux_cdev *ldev;
1429 	ssize_t bytes;
1430 	int error;
1431 
1432 	filp = (struct linux_file *)file->f_data;
1433 	filp->f_flags = file->f_flag;
1434 	/* XXX no support for I/O vectors currently */
1435 	if (uio->uio_iovcnt != 1)
1436 		return (EOPNOTSUPP);
1437 	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1438 		return (EINVAL);
1439 	linux_set_current(td);
1440 	linux_get_fop(filp, &fop, &ldev);
1441 	if (fop->write != NULL) {
1442 		bytes = OPW(file, td, fop->write(filp,
1443 		    uio->uio_iov->iov_base,
1444 		    uio->uio_iov->iov_len, &uio->uio_offset));
1445 		if (bytes >= 0) {
1446 			uio->uio_iov->iov_base =
1447 			    ((uint8_t *)uio->uio_iov->iov_base) + bytes;
1448 			uio->uio_iov->iov_len -= bytes;
1449 			uio->uio_resid -= bytes;
1450 			error = 0;
1451 		} else {
1452 			error = linux_get_error(current, -bytes);
1453 		}
1454 	} else
1455 		error = ENXIO;
1456 
1457 	/* update kqfilter status, if any */
1458 	linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_WRITE);
1459 
1460 	linux_drop_fop(ldev);
1461 
1462 	return (error);
1463 }
1464 
1465 static int
1466 linux_file_poll(struct file *file, int events, struct ucred *active_cred,
1467     struct thread *td)
1468 {
1469 	struct linux_file *filp;
1470 	const struct file_operations *fop;
1471 	struct linux_cdev *ldev;
1472 	int revents;
1473 
1474 	filp = (struct linux_file *)file->f_data;
1475 	filp->f_flags = file->f_flag;
1476 	linux_set_current(td);
1477 	linux_get_fop(filp, &fop, &ldev);
1478 	if (fop->poll != NULL) {
1479 		revents = OPW(file, td, fop->poll(filp,
1480 		    LINUX_POLL_TABLE_NORMAL)) & events;
1481 	} else {
1482 		revents = 0;
1483 	}
1484 	linux_drop_fop(ldev);
1485 	return (revents);
1486 }
1487 
1488 static int
1489 linux_file_close(struct file *file, struct thread *td)
1490 {
1491 	struct linux_file *filp;
1492 	const struct file_operations *fop;
1493 	struct linux_cdev *ldev;
1494 	int error;
1495 
1496 	filp = (struct linux_file *)file->f_data;
1497 
1498 	KASSERT(file_count(filp) == 0,
1499 	    ("File refcount(%d) is not zero", file_count(filp)));
1500 
1501 	if (td == NULL)
1502 		td = curthread;
1503 
1504 	error = 0;
1505 	filp->f_flags = file->f_flag;
1506 	linux_set_current(td);
1507 	linux_poll_wait_dequeue(filp);
1508 	linux_get_fop(filp, &fop, &ldev);
1509 	if (fop->release != NULL)
1510 		error = -OPW(file, td, fop->release(filp->f_vnode, filp));
1511 	funsetown(&filp->f_sigio);
1512 	if (filp->f_vnode != NULL)
1513 		vdrop(filp->f_vnode);
1514 	linux_drop_fop(ldev);
1515 	if (filp->f_cdev != NULL)
1516 		linux_cdev_deref(filp->f_cdev);
1517 	kfree(filp);
1518 
1519 	return (error);
1520 }
1521 
1522 static int
1523 linux_file_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *cred,
1524     struct thread *td)
1525 {
1526 	struct linux_file *filp;
1527 	const struct file_operations *fop;
1528 	struct linux_cdev *ldev;
1529 	int error;
1530 
1531 	error = 0;
1532 	filp = (struct linux_file *)fp->f_data;
1533 	filp->f_flags = fp->f_flag;
1534 	linux_get_fop(filp, &fop, &ldev);
1535 
1536 	linux_set_current(td);
1537 	switch (cmd) {
1538 	case FIONBIO:
1539 		break;
1540 	case FIOASYNC:
1541 		if (fop->fasync == NULL)
1542 			break;
1543 		error = -OPW(fp, td, fop->fasync(0, filp, fp->f_flag & FASYNC));
1544 		break;
1545 	case FIOSETOWN:
1546 		error = fsetown(*(int *)data, &filp->f_sigio);
1547 		if (error == 0) {
1548 			if (fop->fasync == NULL)
1549 				break;
1550 			error = -OPW(fp, td, fop->fasync(0, filp,
1551 			    fp->f_flag & FASYNC));
1552 		}
1553 		break;
1554 	case FIOGETOWN:
1555 		*(int *)data = fgetown(&filp->f_sigio);
1556 		break;
1557 	default:
1558 		error = linux_file_ioctl_sub(fp, filp, fop, cmd, data, td);
1559 		break;
1560 	}
1561 	linux_drop_fop(ldev);
1562 	return (error);
1563 }
1564 
1565 static int
1566 linux_file_mmap_sub(struct thread *td, vm_size_t objsize, vm_prot_t prot,
1567     vm_prot_t *maxprotp, int *flagsp, struct file *fp,
1568     vm_ooffset_t *foff, const struct file_operations *fop, vm_object_t *objp)
1569 {
1570 	/*
1571 	 * Character devices do not provide private mappings
1572 	 * of any kind:
1573 	 */
1574 	if ((*maxprotp & VM_PROT_WRITE) == 0 &&
1575 	    (prot & VM_PROT_WRITE) != 0)
1576 		return (EACCES);
1577 	if ((*flagsp & (MAP_PRIVATE | MAP_COPY)) != 0)
1578 		return (EINVAL);
1579 
1580 	return (linux_file_mmap_single(fp, fop, foff, objsize, objp,
1581 	    (int)prot, td));
1582 }
1583 
1584 static int
1585 linux_file_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
1586     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
1587     struct thread *td)
1588 {
1589 	struct linux_file *filp;
1590 	const struct file_operations *fop;
1591 	struct linux_cdev *ldev;
1592 	struct mount *mp;
1593 	struct vnode *vp;
1594 	vm_object_t object;
1595 	vm_prot_t maxprot;
1596 	int error;
1597 
1598 	filp = (struct linux_file *)fp->f_data;
1599 
1600 	vp = filp->f_vnode;
1601 	if (vp == NULL)
1602 		return (EOPNOTSUPP);
1603 
1604 	/*
1605 	 * Ensure that file and memory protections are
1606 	 * compatible.
1607 	 */
1608 	mp = vp->v_mount;
1609 	if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
1610 		maxprot = VM_PROT_NONE;
1611 		if ((prot & VM_PROT_EXECUTE) != 0)
1612 			return (EACCES);
1613 	} else
1614 		maxprot = VM_PROT_EXECUTE;
1615 	if ((fp->f_flag & FREAD) != 0)
1616 		maxprot |= VM_PROT_READ;
1617 	else if ((prot & VM_PROT_READ) != 0)
1618 		return (EACCES);
1619 
1620 	/*
1621 	 * If we are sharing potential changes via MAP_SHARED and we
1622 	 * are trying to get write permission although we opened it
1623 	 * without asking for it, bail out.
1624 	 *
1625 	 * Note that most character devices always share mappings.
1626 	 *
1627 	 * Rely on linux_file_mmap_sub() to fail invalid MAP_PRIVATE
1628 	 * requests rather than doing it here.
1629 	 */
1630 	if ((flags & MAP_SHARED) != 0) {
1631 		if ((fp->f_flag & FWRITE) != 0)
1632 			maxprot |= VM_PROT_WRITE;
1633 		else if ((prot & VM_PROT_WRITE) != 0)
1634 			return (EACCES);
1635 	}
1636 	maxprot &= cap_maxprot;
1637 
1638 	linux_get_fop(filp, &fop, &ldev);
1639 	error = linux_file_mmap_sub(td, size, prot, &maxprot, &flags, fp,
1640 	    &foff, fop, &object);
1641 	if (error != 0)
1642 		goto out;
1643 
1644 	error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
1645 	    foff, FALSE, td);
1646 	if (error != 0)
1647 		vm_object_deallocate(object);
1648 out:
1649 	linux_drop_fop(ldev);
1650 	return (error);
1651 }
1652 
1653 static int
1654 linux_file_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
1655     struct thread *td)
1656 {
1657 	struct linux_file *filp;
1658 	struct vnode *vp;
1659 	int error;
1660 
1661 	filp = (struct linux_file *)fp->f_data;
1662 	if (filp->f_vnode == NULL)
1663 		return (EOPNOTSUPP);
1664 
1665 	vp = filp->f_vnode;
1666 
1667 	vn_lock(vp, LK_SHARED | LK_RETRY);
1668 	error = vn_stat(vp, sb, td->td_ucred, NOCRED, td);
1669 	VOP_UNLOCK(vp);
1670 
1671 	return (error);
1672 }
1673 
1674 static int
1675 linux_file_fill_kinfo(struct file *fp, struct kinfo_file *kif,
1676     struct filedesc *fdp)
1677 {
1678 	struct linux_file *filp;
1679 	struct vnode *vp;
1680 	int error;
1681 
1682 	filp = fp->f_data;
1683 	vp = filp->f_vnode;
1684 	if (vp == NULL) {
1685 		error = 0;
1686 		kif->kf_type = KF_TYPE_DEV;
1687 	} else {
1688 		vref(vp);
1689 		FILEDESC_SUNLOCK(fdp);
1690 		error = vn_fill_kinfo_vnode(vp, kif);
1691 		vrele(vp);
1692 		kif->kf_type = KF_TYPE_VNODE;
1693 		FILEDESC_SLOCK(fdp);
1694 	}
1695 	return (error);
1696 }
1697 
1698 unsigned int
1699 linux_iminor(struct inode *inode)
1700 {
1701 	struct linux_cdev *ldev;
1702 
1703 	if (inode == NULL || inode->v_rdev == NULL ||
1704 	    inode->v_rdev->si_devsw != &linuxcdevsw)
1705 		return (-1U);
1706 	ldev = inode->v_rdev->si_drv1;
1707 	if (ldev == NULL)
1708 		return (-1U);
1709 
1710 	return (minor(ldev->dev));
1711 }
1712 
1713 struct fileops linuxfileops = {
1714 	.fo_read = linux_file_read,
1715 	.fo_write = linux_file_write,
1716 	.fo_truncate = invfo_truncate,
1717 	.fo_kqfilter = linux_file_kqfilter,
1718 	.fo_stat = linux_file_stat,
1719 	.fo_fill_kinfo = linux_file_fill_kinfo,
1720 	.fo_poll = linux_file_poll,
1721 	.fo_close = linux_file_close,
1722 	.fo_ioctl = linux_file_ioctl,
1723 	.fo_mmap = linux_file_mmap,
1724 	.fo_chmod = invfo_chmod,
1725 	.fo_chown = invfo_chown,
1726 	.fo_sendfile = invfo_sendfile,
1727 	.fo_flags = DFLAG_PASSABLE,
1728 };
1729 
1730 /*
1731  * Hash of vmmap addresses.  This is infrequently accessed and does not
1732  * need to be particularly large.  This is done because we must store the
1733  * caller's idea of the map size to properly unmap.
1734  */
1735 struct vmmap {
1736 	LIST_ENTRY(vmmap)	vm_next;
1737 	void 			*vm_addr;
1738 	unsigned long		vm_size;
1739 };
1740 
1741 struct vmmaphd {
1742 	struct vmmap *lh_first;
1743 };
1744 #define	VMMAP_HASH_SIZE	64
1745 #define	VMMAP_HASH_MASK	(VMMAP_HASH_SIZE - 1)
1746 #define	VM_HASH(addr)	((uintptr_t)(addr) >> PAGE_SHIFT) & VMMAP_HASH_MASK
1747 static struct vmmaphd vmmaphead[VMMAP_HASH_SIZE];
1748 static struct mtx vmmaplock;
1749 
1750 static void
1751 vmmap_add(void *addr, unsigned long size)
1752 {
1753 	struct vmmap *vmmap;
1754 
1755 	vmmap = kmalloc(sizeof(*vmmap), GFP_KERNEL);
1756 	mtx_lock(&vmmaplock);
1757 	vmmap->vm_size = size;
1758 	vmmap->vm_addr = addr;
1759 	LIST_INSERT_HEAD(&vmmaphead[VM_HASH(addr)], vmmap, vm_next);
1760 	mtx_unlock(&vmmaplock);
1761 }
1762 
1763 static struct vmmap *
1764 vmmap_remove(void *addr)
1765 {
1766 	struct vmmap *vmmap;
1767 
1768 	mtx_lock(&vmmaplock);
1769 	LIST_FOREACH(vmmap, &vmmaphead[VM_HASH(addr)], vm_next)
1770 		if (vmmap->vm_addr == addr)
1771 			break;
1772 	if (vmmap)
1773 		LIST_REMOVE(vmmap, vm_next);
1774 	mtx_unlock(&vmmaplock);
1775 
1776 	return (vmmap);
1777 }
1778 
1779 #if defined(__i386__) || defined(__amd64__) || defined(__powerpc__) || defined(__aarch64__)
1780 void *
1781 _ioremap_attr(vm_paddr_t phys_addr, unsigned long size, int attr)
1782 {
1783 	void *addr;
1784 
1785 	addr = pmap_mapdev_attr(phys_addr, size, attr);
1786 	if (addr == NULL)
1787 		return (NULL);
1788 	vmmap_add(addr, size);
1789 
1790 	return (addr);
1791 }
1792 #endif
1793 
1794 void
1795 iounmap(void *addr)
1796 {
1797 	struct vmmap *vmmap;
1798 
1799 	vmmap = vmmap_remove(addr);
1800 	if (vmmap == NULL)
1801 		return;
1802 #if defined(__i386__) || defined(__amd64__) || defined(__powerpc__) || defined(__aarch64__)
1803 	pmap_unmapdev((vm_offset_t)addr, vmmap->vm_size);
1804 #endif
1805 	kfree(vmmap);
1806 }
1807 
1808 
1809 void *
1810 vmap(struct page **pages, unsigned int count, unsigned long flags, int prot)
1811 {
1812 	vm_offset_t off;
1813 	size_t size;
1814 
1815 	size = count * PAGE_SIZE;
1816 	off = kva_alloc(size);
1817 	if (off == 0)
1818 		return (NULL);
1819 	vmmap_add((void *)off, size);
1820 	pmap_qenter(off, pages, count);
1821 
1822 	return ((void *)off);
1823 }
1824 
1825 void
1826 vunmap(void *addr)
1827 {
1828 	struct vmmap *vmmap;
1829 
1830 	vmmap = vmmap_remove(addr);
1831 	if (vmmap == NULL)
1832 		return;
1833 	pmap_qremove((vm_offset_t)addr, vmmap->vm_size / PAGE_SIZE);
1834 	kva_free((vm_offset_t)addr, vmmap->vm_size);
1835 	kfree(vmmap);
1836 }
1837 
1838 char *
1839 kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
1840 {
1841 	unsigned int len;
1842 	char *p;
1843 	va_list aq;
1844 
1845 	va_copy(aq, ap);
1846 	len = vsnprintf(NULL, 0, fmt, aq);
1847 	va_end(aq);
1848 
1849 	p = kmalloc(len + 1, gfp);
1850 	if (p != NULL)
1851 		vsnprintf(p, len + 1, fmt, ap);
1852 
1853 	return (p);
1854 }
1855 
1856 char *
1857 kasprintf(gfp_t gfp, const char *fmt, ...)
1858 {
1859 	va_list ap;
1860 	char *p;
1861 
1862 	va_start(ap, fmt);
1863 	p = kvasprintf(gfp, fmt, ap);
1864 	va_end(ap);
1865 
1866 	return (p);
1867 }
1868 
1869 static void
1870 linux_timer_callback_wrapper(void *context)
1871 {
1872 	struct timer_list *timer;
1873 
1874 	linux_set_current(curthread);
1875 
1876 	timer = context;
1877 	timer->function(timer->data);
1878 }
1879 
1880 void
1881 mod_timer(struct timer_list *timer, int expires)
1882 {
1883 
1884 	timer->expires = expires;
1885 	callout_reset(&timer->callout,
1886 	    linux_timer_jiffies_until(expires),
1887 	    &linux_timer_callback_wrapper, timer);
1888 }
1889 
1890 void
1891 add_timer(struct timer_list *timer)
1892 {
1893 
1894 	callout_reset(&timer->callout,
1895 	    linux_timer_jiffies_until(timer->expires),
1896 	    &linux_timer_callback_wrapper, timer);
1897 }
1898 
1899 void
1900 add_timer_on(struct timer_list *timer, int cpu)
1901 {
1902 
1903 	callout_reset_on(&timer->callout,
1904 	    linux_timer_jiffies_until(timer->expires),
1905 	    &linux_timer_callback_wrapper, timer, cpu);
1906 }
1907 
1908 int
1909 del_timer(struct timer_list *timer)
1910 {
1911 
1912 	if (callout_stop(&(timer)->callout) == -1)
1913 		return (0);
1914 	return (1);
1915 }
1916 
1917 static void
1918 linux_timer_init(void *arg)
1919 {
1920 
1921 	/*
1922 	 * Compute an internal HZ value which can divide 2**32 to
1923 	 * avoid timer rounding problems when the tick value wraps
1924 	 * around 2**32:
1925 	 */
1926 	linux_timer_hz_mask = 1;
1927 	while (linux_timer_hz_mask < (unsigned long)hz)
1928 		linux_timer_hz_mask *= 2;
1929 	linux_timer_hz_mask--;
1930 }
1931 SYSINIT(linux_timer, SI_SUB_DRIVERS, SI_ORDER_FIRST, linux_timer_init, NULL);
1932 
1933 void
1934 linux_complete_common(struct completion *c, int all)
1935 {
1936 	int wakeup_swapper;
1937 
1938 	sleepq_lock(c);
1939 	if (all) {
1940 		c->done = UINT_MAX;
1941 		wakeup_swapper = sleepq_broadcast(c, SLEEPQ_SLEEP, 0, 0);
1942 	} else {
1943 		if (c->done != UINT_MAX)
1944 			c->done++;
1945 		wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);
1946 	}
1947 	sleepq_release(c);
1948 	if (wakeup_swapper)
1949 		kick_proc0();
1950 }
1951 
1952 /*
1953  * Indefinite wait for done != 0 with or without signals.
1954  */
1955 int
1956 linux_wait_for_common(struct completion *c, int flags)
1957 {
1958 	struct task_struct *task;
1959 	int error;
1960 
1961 	if (SCHEDULER_STOPPED())
1962 		return (0);
1963 
1964 	task = current;
1965 
1966 	if (flags != 0)
1967 		flags = SLEEPQ_INTERRUPTIBLE | SLEEPQ_SLEEP;
1968 	else
1969 		flags = SLEEPQ_SLEEP;
1970 	error = 0;
1971 	for (;;) {
1972 		sleepq_lock(c);
1973 		if (c->done)
1974 			break;
1975 		sleepq_add(c, NULL, "completion", flags, 0);
1976 		if (flags & SLEEPQ_INTERRUPTIBLE) {
1977 			DROP_GIANT();
1978 			error = -sleepq_wait_sig(c, 0);
1979 			PICKUP_GIANT();
1980 			if (error != 0) {
1981 				linux_schedule_save_interrupt_value(task, error);
1982 				error = -ERESTARTSYS;
1983 				goto intr;
1984 			}
1985 		} else {
1986 			DROP_GIANT();
1987 			sleepq_wait(c, 0);
1988 			PICKUP_GIANT();
1989 		}
1990 	}
1991 	if (c->done != UINT_MAX)
1992 		c->done--;
1993 	sleepq_release(c);
1994 
1995 intr:
1996 	return (error);
1997 }
1998 
1999 /*
2000  * Time limited wait for done != 0 with or without signals.
2001  */
2002 int
2003 linux_wait_for_timeout_common(struct completion *c, int timeout, int flags)
2004 {
2005 	struct task_struct *task;
2006 	int end = jiffies + timeout;
2007 	int error;
2008 
2009 	if (SCHEDULER_STOPPED())
2010 		return (0);
2011 
2012 	task = current;
2013 
2014 	if (flags != 0)
2015 		flags = SLEEPQ_INTERRUPTIBLE | SLEEPQ_SLEEP;
2016 	else
2017 		flags = SLEEPQ_SLEEP;
2018 
2019 	for (;;) {
2020 		sleepq_lock(c);
2021 		if (c->done)
2022 			break;
2023 		sleepq_add(c, NULL, "completion", flags, 0);
2024 		sleepq_set_timeout(c, linux_timer_jiffies_until(end));
2025 
2026 		DROP_GIANT();
2027 		if (flags & SLEEPQ_INTERRUPTIBLE)
2028 			error = -sleepq_timedwait_sig(c, 0);
2029 		else
2030 			error = -sleepq_timedwait(c, 0);
2031 		PICKUP_GIANT();
2032 
2033 		if (error != 0) {
2034 			/* check for timeout */
2035 			if (error == -EWOULDBLOCK) {
2036 				error = 0;	/* timeout */
2037 			} else {
2038 				/* signal happened */
2039 				linux_schedule_save_interrupt_value(task, error);
2040 				error = -ERESTARTSYS;
2041 			}
2042 			goto done;
2043 		}
2044 	}
2045 	if (c->done != UINT_MAX)
2046 		c->done--;
2047 	sleepq_release(c);
2048 
2049 	/* return how many jiffies are left */
2050 	error = linux_timer_jiffies_until(end);
2051 done:
2052 	return (error);
2053 }
2054 
2055 int
2056 linux_try_wait_for_completion(struct completion *c)
2057 {
2058 	int isdone;
2059 
2060 	sleepq_lock(c);
2061 	isdone = (c->done != 0);
2062 	if (c->done != 0 && c->done != UINT_MAX)
2063 		c->done--;
2064 	sleepq_release(c);
2065 	return (isdone);
2066 }
2067 
2068 int
2069 linux_completion_done(struct completion *c)
2070 {
2071 	int isdone;
2072 
2073 	sleepq_lock(c);
2074 	isdone = (c->done != 0);
2075 	sleepq_release(c);
2076 	return (isdone);
2077 }
2078 
2079 static void
2080 linux_cdev_deref(struct linux_cdev *ldev)
2081 {
2082 
2083 	if (refcount_release(&ldev->refs))
2084 		kfree(ldev);
2085 }
2086 
2087 static void
2088 linux_cdev_release(struct kobject *kobj)
2089 {
2090 	struct linux_cdev *cdev;
2091 	struct kobject *parent;
2092 
2093 	cdev = container_of(kobj, struct linux_cdev, kobj);
2094 	parent = kobj->parent;
2095 	linux_destroy_dev(cdev);
2096 	linux_cdev_deref(cdev);
2097 	kobject_put(parent);
2098 }
2099 
2100 static void
2101 linux_cdev_static_release(struct kobject *kobj)
2102 {
2103 	struct linux_cdev *cdev;
2104 	struct kobject *parent;
2105 
2106 	cdev = container_of(kobj, struct linux_cdev, kobj);
2107 	parent = kobj->parent;
2108 	linux_destroy_dev(cdev);
2109 	kobject_put(parent);
2110 }
2111 
2112 void
2113 linux_destroy_dev(struct linux_cdev *ldev)
2114 {
2115 
2116 	if (ldev->cdev == NULL)
2117 		return;
2118 
2119 	MPASS((ldev->siref & LDEV_SI_DTR) == 0);
2120 	atomic_set_int(&ldev->siref, LDEV_SI_DTR);
2121 	while ((atomic_load_int(&ldev->siref) & ~LDEV_SI_DTR) != 0)
2122 		pause("ldevdtr", hz / 4);
2123 
2124 	destroy_dev(ldev->cdev);
2125 	ldev->cdev = NULL;
2126 }
2127 
2128 const struct kobj_type linux_cdev_ktype = {
2129 	.release = linux_cdev_release,
2130 };
2131 
2132 const struct kobj_type linux_cdev_static_ktype = {
2133 	.release = linux_cdev_static_release,
2134 };
2135 
2136 static void
2137 linux_handle_ifnet_link_event(void *arg, struct ifnet *ifp, int linkstate)
2138 {
2139 	struct notifier_block *nb;
2140 
2141 	nb = arg;
2142 	if (linkstate == LINK_STATE_UP)
2143 		nb->notifier_call(nb, NETDEV_UP, ifp);
2144 	else
2145 		nb->notifier_call(nb, NETDEV_DOWN, ifp);
2146 }
2147 
2148 static void
2149 linux_handle_ifnet_arrival_event(void *arg, struct ifnet *ifp)
2150 {
2151 	struct notifier_block *nb;
2152 
2153 	nb = arg;
2154 	nb->notifier_call(nb, NETDEV_REGISTER, ifp);
2155 }
2156 
2157 static void
2158 linux_handle_ifnet_departure_event(void *arg, struct ifnet *ifp)
2159 {
2160 	struct notifier_block *nb;
2161 
2162 	nb = arg;
2163 	nb->notifier_call(nb, NETDEV_UNREGISTER, ifp);
2164 }
2165 
2166 static void
2167 linux_handle_iflladdr_event(void *arg, struct ifnet *ifp)
2168 {
2169 	struct notifier_block *nb;
2170 
2171 	nb = arg;
2172 	nb->notifier_call(nb, NETDEV_CHANGEADDR, ifp);
2173 }
2174 
2175 static void
2176 linux_handle_ifaddr_event(void *arg, struct ifnet *ifp)
2177 {
2178 	struct notifier_block *nb;
2179 
2180 	nb = arg;
2181 	nb->notifier_call(nb, NETDEV_CHANGEIFADDR, ifp);
2182 }
2183 
2184 int
2185 register_netdevice_notifier(struct notifier_block *nb)
2186 {
2187 
2188 	nb->tags[NETDEV_UP] = EVENTHANDLER_REGISTER(
2189 	    ifnet_link_event, linux_handle_ifnet_link_event, nb, 0);
2190 	nb->tags[NETDEV_REGISTER] = EVENTHANDLER_REGISTER(
2191 	    ifnet_arrival_event, linux_handle_ifnet_arrival_event, nb, 0);
2192 	nb->tags[NETDEV_UNREGISTER] = EVENTHANDLER_REGISTER(
2193 	    ifnet_departure_event, linux_handle_ifnet_departure_event, nb, 0);
2194 	nb->tags[NETDEV_CHANGEADDR] = EVENTHANDLER_REGISTER(
2195 	    iflladdr_event, linux_handle_iflladdr_event, nb, 0);
2196 
2197 	return (0);
2198 }
2199 
2200 int
2201 register_inetaddr_notifier(struct notifier_block *nb)
2202 {
2203 
2204 	nb->tags[NETDEV_CHANGEIFADDR] = EVENTHANDLER_REGISTER(
2205 	    ifaddr_event, linux_handle_ifaddr_event, nb, 0);
2206 	return (0);
2207 }
2208 
2209 int
2210 unregister_netdevice_notifier(struct notifier_block *nb)
2211 {
2212 
2213 	EVENTHANDLER_DEREGISTER(ifnet_link_event,
2214 	    nb->tags[NETDEV_UP]);
2215 	EVENTHANDLER_DEREGISTER(ifnet_arrival_event,
2216 	    nb->tags[NETDEV_REGISTER]);
2217 	EVENTHANDLER_DEREGISTER(ifnet_departure_event,
2218 	    nb->tags[NETDEV_UNREGISTER]);
2219 	EVENTHANDLER_DEREGISTER(iflladdr_event,
2220 	    nb->tags[NETDEV_CHANGEADDR]);
2221 
2222 	return (0);
2223 }
2224 
2225 int
2226 unregister_inetaddr_notifier(struct notifier_block *nb)
2227 {
2228 
2229 	EVENTHANDLER_DEREGISTER(ifaddr_event,
2230 	    nb->tags[NETDEV_CHANGEIFADDR]);
2231 
2232 	return (0);
2233 }
2234 
2235 struct list_sort_thunk {
2236 	int (*cmp)(void *, struct list_head *, struct list_head *);
2237 	void *priv;
2238 };
2239 
2240 static inline int
2241 linux_le_cmp(void *priv, const void *d1, const void *d2)
2242 {
2243 	struct list_head *le1, *le2;
2244 	struct list_sort_thunk *thunk;
2245 
2246 	thunk = priv;
2247 	le1 = *(__DECONST(struct list_head **, d1));
2248 	le2 = *(__DECONST(struct list_head **, d2));
2249 	return ((thunk->cmp)(thunk->priv, le1, le2));
2250 }
2251 
2252 void
2253 list_sort(void *priv, struct list_head *head, int (*cmp)(void *priv,
2254     struct list_head *a, struct list_head *b))
2255 {
2256 	struct list_sort_thunk thunk;
2257 	struct list_head **ar, *le;
2258 	size_t count, i;
2259 
2260 	count = 0;
2261 	list_for_each(le, head)
2262 		count++;
2263 	ar = malloc(sizeof(struct list_head *) * count, M_KMALLOC, M_WAITOK);
2264 	i = 0;
2265 	list_for_each(le, head)
2266 		ar[i++] = le;
2267 	thunk.cmp = cmp;
2268 	thunk.priv = priv;
2269 	qsort_r(ar, count, sizeof(struct list_head *), &thunk, linux_le_cmp);
2270 	INIT_LIST_HEAD(head);
2271 	for (i = 0; i < count; i++)
2272 		list_add_tail(ar[i], head);
2273 	free(ar, M_KMALLOC);
2274 }
2275 
2276 void
2277 linux_irq_handler(void *ent)
2278 {
2279 	struct irq_ent *irqe;
2280 
2281 	linux_set_current(curthread);
2282 
2283 	irqe = ent;
2284 	irqe->handler(irqe->irq, irqe->arg);
2285 }
2286 
2287 #if defined(__i386__) || defined(__amd64__)
2288 int
2289 linux_wbinvd_on_all_cpus(void)
2290 {
2291 
2292 	pmap_invalidate_cache();
2293 	return (0);
2294 }
2295 #endif
2296 
2297 int
2298 linux_on_each_cpu(void callback(void *), void *data)
2299 {
2300 
2301 	smp_rendezvous(smp_no_rendezvous_barrier, callback,
2302 	    smp_no_rendezvous_barrier, data);
2303 	return (0);
2304 }
2305 
2306 int
2307 linux_in_atomic(void)
2308 {
2309 
2310 	return ((curthread->td_pflags & TDP_NOFAULTING) != 0);
2311 }
2312 
2313 struct linux_cdev *
2314 linux_find_cdev(const char *name, unsigned major, unsigned minor)
2315 {
2316 	dev_t dev = MKDEV(major, minor);
2317 	struct cdev *cdev;
2318 
2319 	dev_lock();
2320 	LIST_FOREACH(cdev, &linuxcdevsw.d_devs, si_list) {
2321 		struct linux_cdev *ldev = cdev->si_drv1;
2322 		if (ldev->dev == dev &&
2323 		    strcmp(kobject_name(&ldev->kobj), name) == 0) {
2324 			break;
2325 		}
2326 	}
2327 	dev_unlock();
2328 
2329 	return (cdev != NULL ? cdev->si_drv1 : NULL);
2330 }
2331 
2332 int
2333 __register_chrdev(unsigned int major, unsigned int baseminor,
2334     unsigned int count, const char *name,
2335     const struct file_operations *fops)
2336 {
2337 	struct linux_cdev *cdev;
2338 	int ret = 0;
2339 	int i;
2340 
2341 	for (i = baseminor; i < baseminor + count; i++) {
2342 		cdev = cdev_alloc();
2343 		cdev->ops = fops;
2344 		kobject_set_name(&cdev->kobj, name);
2345 
2346 		ret = cdev_add(cdev, makedev(major, i), 1);
2347 		if (ret != 0)
2348 			break;
2349 	}
2350 	return (ret);
2351 }
2352 
2353 int
2354 __register_chrdev_p(unsigned int major, unsigned int baseminor,
2355     unsigned int count, const char *name,
2356     const struct file_operations *fops, uid_t uid,
2357     gid_t gid, int mode)
2358 {
2359 	struct linux_cdev *cdev;
2360 	int ret = 0;
2361 	int i;
2362 
2363 	for (i = baseminor; i < baseminor + count; i++) {
2364 		cdev = cdev_alloc();
2365 		cdev->ops = fops;
2366 		kobject_set_name(&cdev->kobj, name);
2367 
2368 		ret = cdev_add_ext(cdev, makedev(major, i), uid, gid, mode);
2369 		if (ret != 0)
2370 			break;
2371 	}
2372 	return (ret);
2373 }
2374 
2375 void
2376 __unregister_chrdev(unsigned int major, unsigned int baseminor,
2377     unsigned int count, const char *name)
2378 {
2379 	struct linux_cdev *cdevp;
2380 	int i;
2381 
2382 	for (i = baseminor; i < baseminor + count; i++) {
2383 		cdevp = linux_find_cdev(name, major, i);
2384 		if (cdevp != NULL)
2385 			cdev_del(cdevp);
2386 	}
2387 }
2388 
2389 void
2390 linux_dump_stack(void)
2391 {
2392 #ifdef STACK
2393 	struct stack st;
2394 
2395 	stack_zero(&st);
2396 	stack_save(&st);
2397 	stack_print(&st);
2398 #endif
2399 }
2400 
2401 #if defined(__i386__) || defined(__amd64__)
2402 bool linux_cpu_has_clflush;
2403 #endif
2404 
2405 static void
2406 linux_compat_init(void *arg)
2407 {
2408 	struct sysctl_oid *rootoid;
2409 	int i;
2410 
2411 #if defined(__i386__) || defined(__amd64__)
2412 	linux_cpu_has_clflush = (cpu_feature & CPUID_CLFSH);
2413 #endif
2414 	rw_init(&linux_vma_lock, "lkpi-vma-lock");
2415 
2416 	rootoid = SYSCTL_ADD_ROOT_NODE(NULL,
2417 	    OID_AUTO, "sys", CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, "sys");
2418 	kobject_init(&linux_class_root, &linux_class_ktype);
2419 	kobject_set_name(&linux_class_root, "class");
2420 	linux_class_root.oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(rootoid),
2421 	    OID_AUTO, "class", CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, "class");
2422 	kobject_init(&linux_root_device.kobj, &linux_dev_ktype);
2423 	kobject_set_name(&linux_root_device.kobj, "device");
2424 	linux_root_device.kobj.oidp = SYSCTL_ADD_NODE(NULL,
2425 	    SYSCTL_CHILDREN(rootoid), OID_AUTO, "device", CTLFLAG_RD, NULL,
2426 	    "device");
2427 	linux_root_device.bsddev = root_bus;
2428 	linux_class_misc.name = "misc";
2429 	class_register(&linux_class_misc);
2430 	INIT_LIST_HEAD(&pci_drivers);
2431 	INIT_LIST_HEAD(&pci_devices);
2432 	spin_lock_init(&pci_lock);
2433 	mtx_init(&vmmaplock, "IO Map lock", NULL, MTX_DEF);
2434 	for (i = 0; i < VMMAP_HASH_SIZE; i++)
2435 		LIST_INIT(&vmmaphead[i]);
2436 }
2437 SYSINIT(linux_compat, SI_SUB_DRIVERS, SI_ORDER_SECOND, linux_compat_init, NULL);
2438 
2439 static void
2440 linux_compat_uninit(void *arg)
2441 {
2442 	linux_kobject_kfree_name(&linux_class_root);
2443 	linux_kobject_kfree_name(&linux_root_device.kobj);
2444 	linux_kobject_kfree_name(&linux_class_misc.kobj);
2445 
2446 	mtx_destroy(&vmmaplock);
2447 	spin_lock_destroy(&pci_lock);
2448 	rw_destroy(&linux_vma_lock);
2449 }
2450 SYSUNINIT(linux_compat, SI_SUB_DRIVERS, SI_ORDER_SECOND, linux_compat_uninit, NULL);
2451 
2452 /*
2453  * NOTE: Linux frequently uses "unsigned long" for pointer to integer
2454  * conversion and vice versa, where in FreeBSD "uintptr_t" would be
2455  * used. Assert these types have the same size, else some parts of the
2456  * LinuxKPI may not work like expected:
2457  */
2458 CTASSERT(sizeof(unsigned long) == sizeof(uintptr_t));
2459