xref: /freebsd/sys/compat/linuxkpi/common/src/linux_compat.c (revision 9c9d7fdd9f0041783955c5f540ac55a900877c0c)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2021 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 #include "opt_stack.h"
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/malloc.h>
36 #include <sys/kernel.h>
37 #include <sys/sysctl.h>
38 #include <sys/proc.h>
39 #include <sys/sglist.h>
40 #include <sys/sleepqueue.h>
41 #include <sys/refcount.h>
42 #include <sys/lock.h>
43 #include <sys/mutex.h>
44 #include <sys/bus.h>
45 #include <sys/eventhandler.h>
46 #include <sys/fcntl.h>
47 #include <sys/file.h>
48 #include <sys/filio.h>
49 #include <sys/rwlock.h>
50 #include <sys/mman.h>
51 #include <sys/stack.h>
52 #include <sys/sysent.h>
53 #include <sys/time.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/cpu.h>
70 #include <linux/device.h>
71 #include <linux/slab.h>
72 #include <linux/module.h>
73 #include <linux/moduleparam.h>
74 #include <linux/cdev.h>
75 #include <linux/file.h>
76 #include <linux/sysfs.h>
77 #include <linux/mm.h>
78 #include <linux/io.h>
79 #include <linux/vmalloc.h>
80 #include <linux/netdevice.h>
81 #include <linux/timer.h>
82 #include <linux/interrupt.h>
83 #include <linux/uaccess.h>
84 #include <linux/utsname.h>
85 #include <linux/list.h>
86 #include <linux/kthread.h>
87 #include <linux/kernel.h>
88 #include <linux/compat.h>
89 #include <linux/io-mapping.h>
90 #include <linux/poll.h>
91 #include <linux/smp.h>
92 #include <linux/wait_bit.h>
93 #include <linux/rcupdate.h>
94 #include <linux/interval_tree.h>
95 #include <linux/interval_tree_generic.h>
96 
97 #if defined(__i386__) || defined(__amd64__)
98 #include <asm/smp.h>
99 #include <asm/processor.h>
100 #endif
101 
102 SYSCTL_NODE(_compat, OID_AUTO, linuxkpi, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
103     "LinuxKPI parameters");
104 
105 int linuxkpi_debug;
106 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, debug, CTLFLAG_RWTUN,
107     &linuxkpi_debug, 0, "Set to enable pr_debug() prints. Clear to disable.");
108 
109 int linuxkpi_warn_dump_stack = 0;
110 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, warn_dump_stack, CTLFLAG_RWTUN,
111     &linuxkpi_warn_dump_stack, 0,
112     "Set to enable stack traces from WARN_ON(). Clear to disable.");
113 
114 static struct timeval lkpi_net_lastlog;
115 static int lkpi_net_curpps;
116 static int lkpi_net_maxpps = 99;
117 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, net_ratelimit, CTLFLAG_RWTUN,
118     &lkpi_net_maxpps, 0, "Limit number of LinuxKPI net messages per second.");
119 
120 MALLOC_DEFINE(M_KMALLOC, "lkpikmalloc", "Linux kmalloc compat");
121 
122 #include <linux/rbtree.h>
123 /* Undo Linux compat changes. */
124 #undef RB_ROOT
125 #undef file
126 #undef cdev
127 #define	RB_ROOT(head)	(head)->rbh_root
128 
129 static void linux_destroy_dev(struct linux_cdev *);
130 static void linux_cdev_deref(struct linux_cdev *ldev);
131 static struct vm_area_struct *linux_cdev_handle_find(void *handle);
132 
133 cpumask_t cpu_online_mask;
134 static cpumask_t **static_single_cpu_mask;
135 static cpumask_t *static_single_cpu_mask_lcs;
136 struct kobject linux_class_root;
137 struct device linux_root_device;
138 struct class linux_class_misc;
139 struct list_head pci_drivers;
140 struct list_head pci_devices;
141 spinlock_t pci_lock;
142 struct uts_namespace init_uts_ns;
143 
144 unsigned long linux_timer_hz_mask;
145 
146 wait_queue_head_t linux_bit_waitq;
147 wait_queue_head_t linux_var_waitq;
148 
149 int
150 panic_cmp(struct rb_node *one, struct rb_node *two)
151 {
152 	panic("no cmp");
153 }
154 
155 RB_GENERATE(linux_root, rb_node, __entry, panic_cmp);
156 
157 #define	START(node)	((node)->start)
158 #define	LAST(node)	((node)->last)
159 
160 INTERVAL_TREE_DEFINE(struct interval_tree_node, rb, unsigned long,, START,
161     LAST,, lkpi_interval_tree)
162 
163 static void
164 linux_device_release(struct device *dev)
165 {
166 	pr_debug("linux_device_release: %s\n", dev_name(dev));
167 	kfree(dev);
168 }
169 
170 static ssize_t
171 linux_class_show(struct kobject *kobj, struct attribute *attr, char *buf)
172 {
173 	struct class_attribute *dattr;
174 	ssize_t error;
175 
176 	dattr = container_of(attr, struct class_attribute, attr);
177 	error = -EIO;
178 	if (dattr->show)
179 		error = dattr->show(container_of(kobj, struct class, kobj),
180 		    dattr, buf);
181 	return (error);
182 }
183 
184 static ssize_t
185 linux_class_store(struct kobject *kobj, struct attribute *attr, const char *buf,
186     size_t count)
187 {
188 	struct class_attribute *dattr;
189 	ssize_t error;
190 
191 	dattr = container_of(attr, struct class_attribute, attr);
192 	error = -EIO;
193 	if (dattr->store)
194 		error = dattr->store(container_of(kobj, struct class, kobj),
195 		    dattr, buf, count);
196 	return (error);
197 }
198 
199 static void
200 linux_class_release(struct kobject *kobj)
201 {
202 	struct class *class;
203 
204 	class = container_of(kobj, struct class, kobj);
205 	if (class->class_release)
206 		class->class_release(class);
207 }
208 
209 static const struct sysfs_ops linux_class_sysfs = {
210 	.show  = linux_class_show,
211 	.store = linux_class_store,
212 };
213 
214 const struct kobj_type linux_class_ktype = {
215 	.release = linux_class_release,
216 	.sysfs_ops = &linux_class_sysfs
217 };
218 
219 static void
220 linux_dev_release(struct kobject *kobj)
221 {
222 	struct device *dev;
223 
224 	dev = container_of(kobj, struct device, kobj);
225 	/* This is the precedence defined by linux. */
226 	if (dev->release)
227 		dev->release(dev);
228 	else if (dev->class && dev->class->dev_release)
229 		dev->class->dev_release(dev);
230 }
231 
232 static ssize_t
233 linux_dev_show(struct kobject *kobj, struct attribute *attr, char *buf)
234 {
235 	struct device_attribute *dattr;
236 	ssize_t error;
237 
238 	dattr = container_of(attr, struct device_attribute, attr);
239 	error = -EIO;
240 	if (dattr->show)
241 		error = dattr->show(container_of(kobj, struct device, kobj),
242 		    dattr, buf);
243 	return (error);
244 }
245 
246 static ssize_t
247 linux_dev_store(struct kobject *kobj, struct attribute *attr, const char *buf,
248     size_t count)
249 {
250 	struct device_attribute *dattr;
251 	ssize_t error;
252 
253 	dattr = container_of(attr, struct device_attribute, attr);
254 	error = -EIO;
255 	if (dattr->store)
256 		error = dattr->store(container_of(kobj, struct device, kobj),
257 		    dattr, buf, count);
258 	return (error);
259 }
260 
261 static const struct sysfs_ops linux_dev_sysfs = {
262 	.show  = linux_dev_show,
263 	.store = linux_dev_store,
264 };
265 
266 const struct kobj_type linux_dev_ktype = {
267 	.release = linux_dev_release,
268 	.sysfs_ops = &linux_dev_sysfs
269 };
270 
271 struct device *
272 device_create(struct class *class, struct device *parent, dev_t devt,
273     void *drvdata, const char *fmt, ...)
274 {
275 	struct device *dev;
276 	va_list args;
277 
278 	dev = kzalloc(sizeof(*dev), M_WAITOK);
279 	dev->parent = parent;
280 	dev->class = class;
281 	dev->devt = devt;
282 	dev->driver_data = drvdata;
283 	dev->release = linux_device_release;
284 	va_start(args, fmt);
285 	kobject_set_name_vargs(&dev->kobj, fmt, args);
286 	va_end(args);
287 	device_register(dev);
288 
289 	return (dev);
290 }
291 
292 struct device *
293 device_create_groups_vargs(struct class *class, struct device *parent,
294     dev_t devt, void *drvdata, const struct attribute_group **groups,
295     const char *fmt, va_list args)
296 {
297 	struct device *dev = NULL;
298 	int retval = -ENODEV;
299 
300 	if (class == NULL || IS_ERR(class))
301 		goto error;
302 
303 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
304 	if (!dev) {
305 		retval = -ENOMEM;
306 		goto error;
307 	}
308 
309 	dev->devt = devt;
310 	dev->class = class;
311 	dev->parent = parent;
312 	dev->groups = groups;
313 	dev->release = device_create_release;
314 	/* device_initialize() needs the class and parent to be set */
315 	device_initialize(dev);
316 	dev_set_drvdata(dev, drvdata);
317 
318 	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
319 	if (retval)
320 		goto error;
321 
322 	retval = device_add(dev);
323 	if (retval)
324 		goto error;
325 
326 	return dev;
327 
328 error:
329 	put_device(dev);
330 	return ERR_PTR(retval);
331 }
332 
333 struct class *
334 class_create(struct module *owner, const char *name)
335 {
336 	struct class *class;
337 	int error;
338 
339 	class = kzalloc(sizeof(*class), M_WAITOK);
340 	class->owner = owner;
341 	class->name = name;
342 	class->class_release = linux_class_kfree;
343 	error = class_register(class);
344 	if (error) {
345 		kfree(class);
346 		return (NULL);
347 	}
348 
349 	return (class);
350 }
351 
352 static void
353 linux_kq_lock(void *arg)
354 {
355 	spinlock_t *s = arg;
356 
357 	spin_lock(s);
358 }
359 static void
360 linux_kq_unlock(void *arg)
361 {
362 	spinlock_t *s = arg;
363 
364 	spin_unlock(s);
365 }
366 
367 static void
368 linux_kq_assert_lock(void *arg, int what)
369 {
370 #ifdef INVARIANTS
371 	spinlock_t *s = arg;
372 
373 	if (what == LA_LOCKED)
374 		mtx_assert(&s->m, MA_OWNED);
375 	else
376 		mtx_assert(&s->m, MA_NOTOWNED);
377 #endif
378 }
379 
380 static void
381 linux_file_kqfilter_poll(struct linux_file *, int);
382 
383 struct linux_file *
384 linux_file_alloc(void)
385 {
386 	struct linux_file *filp;
387 
388 	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
389 
390 	/* set initial refcount */
391 	filp->f_count = 1;
392 
393 	/* setup fields needed by kqueue support */
394 	spin_lock_init(&filp->f_kqlock);
395 	knlist_init(&filp->f_selinfo.si_note, &filp->f_kqlock,
396 	    linux_kq_lock, linux_kq_unlock, linux_kq_assert_lock);
397 
398 	return (filp);
399 }
400 
401 void
402 linux_file_free(struct linux_file *filp)
403 {
404 	if (filp->_file == NULL) {
405 		if (filp->f_op != NULL && filp->f_op->release != NULL)
406 			filp->f_op->release(filp->f_vnode, filp);
407 		if (filp->f_shmem != NULL)
408 			vm_object_deallocate(filp->f_shmem);
409 		kfree_rcu(filp, rcu);
410 	} else {
411 		/*
412 		 * The close method of the character device or file
413 		 * will free the linux_file structure:
414 		 */
415 		_fdrop(filp->_file, curthread);
416 	}
417 }
418 
419 struct linux_cdev *
420 cdev_alloc(void)
421 {
422 	struct linux_cdev *cdev;
423 
424 	cdev = kzalloc(sizeof(struct linux_cdev), M_WAITOK);
425 	kobject_init(&cdev->kobj, &linux_cdev_ktype);
426 	cdev->refs = 1;
427 	return (cdev);
428 }
429 
430 static int
431 linux_cdev_pager_fault(vm_object_t vm_obj, vm_ooffset_t offset, int prot,
432     vm_page_t *mres)
433 {
434 	struct vm_area_struct *vmap;
435 
436 	vmap = linux_cdev_handle_find(vm_obj->handle);
437 
438 	MPASS(vmap != NULL);
439 	MPASS(vmap->vm_private_data == vm_obj->handle);
440 
441 	if (likely(vmap->vm_ops != NULL && offset < vmap->vm_len)) {
442 		vm_paddr_t paddr = IDX_TO_OFF(vmap->vm_pfn) + offset;
443 		vm_page_t page;
444 
445 		if (((*mres)->flags & PG_FICTITIOUS) != 0) {
446 			/*
447 			 * If the passed in result page is a fake
448 			 * page, update it with the new physical
449 			 * address.
450 			 */
451 			page = *mres;
452 			vm_page_updatefake(page, paddr, vm_obj->memattr);
453 		} else {
454 			/*
455 			 * Replace the passed in "mres" page with our
456 			 * own fake page and free up the all of the
457 			 * original pages.
458 			 */
459 			VM_OBJECT_WUNLOCK(vm_obj);
460 			page = vm_page_getfake(paddr, vm_obj->memattr);
461 			VM_OBJECT_WLOCK(vm_obj);
462 
463 			vm_page_replace(page, vm_obj, (*mres)->pindex, *mres);
464 			*mres = page;
465 		}
466 		vm_page_valid(page);
467 		return (VM_PAGER_OK);
468 	}
469 	return (VM_PAGER_FAIL);
470 }
471 
472 static int
473 linux_cdev_pager_populate(vm_object_t vm_obj, vm_pindex_t pidx, int fault_type,
474     vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
475 {
476 	struct vm_area_struct *vmap;
477 	int err;
478 
479 	/* get VM area structure */
480 	vmap = linux_cdev_handle_find(vm_obj->handle);
481 	MPASS(vmap != NULL);
482 	MPASS(vmap->vm_private_data == vm_obj->handle);
483 
484 	VM_OBJECT_WUNLOCK(vm_obj);
485 
486 	linux_set_current(curthread);
487 
488 	down_write(&vmap->vm_mm->mmap_sem);
489 	if (unlikely(vmap->vm_ops == NULL)) {
490 		err = VM_FAULT_SIGBUS;
491 	} else {
492 		struct vm_fault vmf;
493 
494 		/* fill out VM fault structure */
495 		vmf.virtual_address = (void *)(uintptr_t)IDX_TO_OFF(pidx);
496 		vmf.flags = (fault_type & VM_PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
497 		vmf.pgoff = 0;
498 		vmf.page = NULL;
499 		vmf.vma = vmap;
500 
501 		vmap->vm_pfn_count = 0;
502 		vmap->vm_pfn_pcount = &vmap->vm_pfn_count;
503 		vmap->vm_obj = vm_obj;
504 
505 		err = vmap->vm_ops->fault(&vmf);
506 
507 		while (vmap->vm_pfn_count == 0 && err == VM_FAULT_NOPAGE) {
508 			kern_yield(PRI_USER);
509 			err = vmap->vm_ops->fault(&vmf);
510 		}
511 	}
512 
513 	/* translate return code */
514 	switch (err) {
515 	case VM_FAULT_OOM:
516 		err = VM_PAGER_AGAIN;
517 		break;
518 	case VM_FAULT_SIGBUS:
519 		err = VM_PAGER_BAD;
520 		break;
521 	case VM_FAULT_NOPAGE:
522 		/*
523 		 * By contract the fault handler will return having
524 		 * busied all the pages itself. If pidx is already
525 		 * found in the object, it will simply xbusy the first
526 		 * page and return with vm_pfn_count set to 1.
527 		 */
528 		*first = vmap->vm_pfn_first;
529 		*last = *first + vmap->vm_pfn_count - 1;
530 		err = VM_PAGER_OK;
531 		break;
532 	default:
533 		err = VM_PAGER_ERROR;
534 		break;
535 	}
536 	up_write(&vmap->vm_mm->mmap_sem);
537 	VM_OBJECT_WLOCK(vm_obj);
538 	return (err);
539 }
540 
541 static struct rwlock linux_vma_lock;
542 static TAILQ_HEAD(, vm_area_struct) linux_vma_head =
543     TAILQ_HEAD_INITIALIZER(linux_vma_head);
544 
545 static void
546 linux_cdev_handle_free(struct vm_area_struct *vmap)
547 {
548 	/* Drop reference on vm_file */
549 	if (vmap->vm_file != NULL)
550 		fput(vmap->vm_file);
551 
552 	/* Drop reference on mm_struct */
553 	mmput(vmap->vm_mm);
554 
555 	kfree(vmap);
556 }
557 
558 static void
559 linux_cdev_handle_remove(struct vm_area_struct *vmap)
560 {
561 	rw_wlock(&linux_vma_lock);
562 	TAILQ_REMOVE(&linux_vma_head, vmap, vm_entry);
563 	rw_wunlock(&linux_vma_lock);
564 }
565 
566 static struct vm_area_struct *
567 linux_cdev_handle_find(void *handle)
568 {
569 	struct vm_area_struct *vmap;
570 
571 	rw_rlock(&linux_vma_lock);
572 	TAILQ_FOREACH(vmap, &linux_vma_head, vm_entry) {
573 		if (vmap->vm_private_data == handle)
574 			break;
575 	}
576 	rw_runlock(&linux_vma_lock);
577 	return (vmap);
578 }
579 
580 static int
581 linux_cdev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
582 		      vm_ooffset_t foff, struct ucred *cred, u_short *color)
583 {
584 
585 	MPASS(linux_cdev_handle_find(handle) != NULL);
586 	*color = 0;
587 	return (0);
588 }
589 
590 static void
591 linux_cdev_pager_dtor(void *handle)
592 {
593 	const struct vm_operations_struct *vm_ops;
594 	struct vm_area_struct *vmap;
595 
596 	vmap = linux_cdev_handle_find(handle);
597 	MPASS(vmap != NULL);
598 
599 	/*
600 	 * Remove handle before calling close operation to prevent
601 	 * other threads from reusing the handle pointer.
602 	 */
603 	linux_cdev_handle_remove(vmap);
604 
605 	down_write(&vmap->vm_mm->mmap_sem);
606 	vm_ops = vmap->vm_ops;
607 	if (likely(vm_ops != NULL))
608 		vm_ops->close(vmap);
609 	up_write(&vmap->vm_mm->mmap_sem);
610 
611 	linux_cdev_handle_free(vmap);
612 }
613 
614 static struct cdev_pager_ops linux_cdev_pager_ops[2] = {
615   {
616 	/* OBJT_MGTDEVICE */
617 	.cdev_pg_populate	= linux_cdev_pager_populate,
618 	.cdev_pg_ctor	= linux_cdev_pager_ctor,
619 	.cdev_pg_dtor	= linux_cdev_pager_dtor
620   },
621   {
622 	/* OBJT_DEVICE */
623 	.cdev_pg_fault	= linux_cdev_pager_fault,
624 	.cdev_pg_ctor	= linux_cdev_pager_ctor,
625 	.cdev_pg_dtor	= linux_cdev_pager_dtor
626   },
627 };
628 
629 int
630 zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
631     unsigned long size)
632 {
633 	vm_object_t obj;
634 	vm_page_t m;
635 
636 	obj = vma->vm_obj;
637 	if (obj == NULL || (obj->flags & OBJ_UNMANAGED) != 0)
638 		return (-ENOTSUP);
639 	VM_OBJECT_RLOCK(obj);
640 	for (m = vm_page_find_least(obj, OFF_TO_IDX(address));
641 	    m != NULL && m->pindex < OFF_TO_IDX(address + size);
642 	    m = TAILQ_NEXT(m, listq))
643 		pmap_remove_all(m);
644 	VM_OBJECT_RUNLOCK(obj);
645 	return (0);
646 }
647 
648 void
649 vma_set_file(struct vm_area_struct *vma, struct linux_file *file)
650 {
651 	struct linux_file *tmp;
652 
653 	/* Changing an anonymous vma with this is illegal */
654 	get_file(file);
655 	tmp = vma->vm_file;
656 	vma->vm_file = file;
657 	fput(tmp);
658 }
659 
660 static struct file_operations dummy_ldev_ops = {
661 	/* XXXKIB */
662 };
663 
664 static struct linux_cdev dummy_ldev = {
665 	.ops = &dummy_ldev_ops,
666 };
667 
668 #define	LDEV_SI_DTR	0x0001
669 #define	LDEV_SI_REF	0x0002
670 
671 static void
672 linux_get_fop(struct linux_file *filp, const struct file_operations **fop,
673     struct linux_cdev **dev)
674 {
675 	struct linux_cdev *ldev;
676 	u_int siref;
677 
678 	ldev = filp->f_cdev;
679 	*fop = filp->f_op;
680 	if (ldev != NULL) {
681 		if (ldev->kobj.ktype == &linux_cdev_static_ktype) {
682 			refcount_acquire(&ldev->refs);
683 		} else {
684 			for (siref = ldev->siref;;) {
685 				if ((siref & LDEV_SI_DTR) != 0) {
686 					ldev = &dummy_ldev;
687 					*fop = ldev->ops;
688 					siref = ldev->siref;
689 					MPASS((ldev->siref & LDEV_SI_DTR) == 0);
690 				} else if (atomic_fcmpset_int(&ldev->siref,
691 				    &siref, siref + LDEV_SI_REF)) {
692 					break;
693 				}
694 			}
695 		}
696 	}
697 	*dev = ldev;
698 }
699 
700 static void
701 linux_drop_fop(struct linux_cdev *ldev)
702 {
703 
704 	if (ldev == NULL)
705 		return;
706 	if (ldev->kobj.ktype == &linux_cdev_static_ktype) {
707 		linux_cdev_deref(ldev);
708 	} else {
709 		MPASS(ldev->kobj.ktype == &linux_cdev_ktype);
710 		MPASS((ldev->siref & ~LDEV_SI_DTR) != 0);
711 		atomic_subtract_int(&ldev->siref, LDEV_SI_REF);
712 	}
713 }
714 
715 #define	OPW(fp,td,code) ({			\
716 	struct file *__fpop;			\
717 	__typeof(code) __retval;		\
718 						\
719 	__fpop = (td)->td_fpop;			\
720 	(td)->td_fpop = (fp);			\
721 	__retval = (code);			\
722 	(td)->td_fpop = __fpop;			\
723 	__retval;				\
724 })
725 
726 static int
727 linux_dev_fdopen(struct cdev *dev, int fflags, struct thread *td,
728     struct file *file)
729 {
730 	struct linux_cdev *ldev;
731 	struct linux_file *filp;
732 	const struct file_operations *fop;
733 	int error;
734 
735 	ldev = dev->si_drv1;
736 
737 	filp = linux_file_alloc();
738 	filp->f_dentry = &filp->f_dentry_store;
739 	filp->f_op = ldev->ops;
740 	filp->f_mode = file->f_flag;
741 	filp->f_flags = file->f_flag;
742 	filp->f_vnode = file->f_vnode;
743 	filp->_file = file;
744 	refcount_acquire(&ldev->refs);
745 	filp->f_cdev = ldev;
746 
747 	linux_set_current(td);
748 	linux_get_fop(filp, &fop, &ldev);
749 
750 	if (fop->open != NULL) {
751 		error = -fop->open(file->f_vnode, filp);
752 		if (error != 0) {
753 			linux_drop_fop(ldev);
754 			linux_cdev_deref(filp->f_cdev);
755 			kfree(filp);
756 			return (error);
757 		}
758 	}
759 
760 	/* hold on to the vnode - used for fstat() */
761 	vhold(filp->f_vnode);
762 
763 	/* release the file from devfs */
764 	finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
765 	linux_drop_fop(ldev);
766 	return (ENXIO);
767 }
768 
769 #define	LINUX_IOCTL_MIN_PTR 0x10000UL
770 #define	LINUX_IOCTL_MAX_PTR (LINUX_IOCTL_MIN_PTR + IOCPARM_MAX)
771 
772 static inline int
773 linux_remap_address(void **uaddr, size_t len)
774 {
775 	uintptr_t uaddr_val = (uintptr_t)(*uaddr);
776 
777 	if (unlikely(uaddr_val >= LINUX_IOCTL_MIN_PTR &&
778 	    uaddr_val < LINUX_IOCTL_MAX_PTR)) {
779 		struct task_struct *pts = current;
780 		if (pts == NULL) {
781 			*uaddr = NULL;
782 			return (1);
783 		}
784 
785 		/* compute data offset */
786 		uaddr_val -= LINUX_IOCTL_MIN_PTR;
787 
788 		/* check that length is within bounds */
789 		if ((len > IOCPARM_MAX) ||
790 		    (uaddr_val + len) > pts->bsd_ioctl_len) {
791 			*uaddr = NULL;
792 			return (1);
793 		}
794 
795 		/* re-add kernel buffer address */
796 		uaddr_val += (uintptr_t)pts->bsd_ioctl_data;
797 
798 		/* update address location */
799 		*uaddr = (void *)uaddr_val;
800 		return (1);
801 	}
802 	return (0);
803 }
804 
805 int
806 linux_copyin(const void *uaddr, void *kaddr, size_t len)
807 {
808 	if (linux_remap_address(__DECONST(void **, &uaddr), len)) {
809 		if (uaddr == NULL)
810 			return (-EFAULT);
811 		memcpy(kaddr, uaddr, len);
812 		return (0);
813 	}
814 	return (-copyin(uaddr, kaddr, len));
815 }
816 
817 int
818 linux_copyout(const void *kaddr, void *uaddr, size_t len)
819 {
820 	if (linux_remap_address(&uaddr, len)) {
821 		if (uaddr == NULL)
822 			return (-EFAULT);
823 		memcpy(uaddr, kaddr, len);
824 		return (0);
825 	}
826 	return (-copyout(kaddr, uaddr, len));
827 }
828 
829 size_t
830 linux_clear_user(void *_uaddr, size_t _len)
831 {
832 	uint8_t *uaddr = _uaddr;
833 	size_t len = _len;
834 
835 	/* make sure uaddr is aligned before going into the fast loop */
836 	while (((uintptr_t)uaddr & 7) != 0 && len > 7) {
837 		if (subyte(uaddr, 0))
838 			return (_len);
839 		uaddr++;
840 		len--;
841 	}
842 
843 	/* zero 8 bytes at a time */
844 	while (len > 7) {
845 #ifdef __LP64__
846 		if (suword64(uaddr, 0))
847 			return (_len);
848 #else
849 		if (suword32(uaddr, 0))
850 			return (_len);
851 		if (suword32(uaddr + 4, 0))
852 			return (_len);
853 #endif
854 		uaddr += 8;
855 		len -= 8;
856 	}
857 
858 	/* zero fill end, if any */
859 	while (len > 0) {
860 		if (subyte(uaddr, 0))
861 			return (_len);
862 		uaddr++;
863 		len--;
864 	}
865 	return (0);
866 }
867 
868 int
869 linux_access_ok(const void *uaddr, size_t len)
870 {
871 	uintptr_t saddr;
872 	uintptr_t eaddr;
873 
874 	/* get start and end address */
875 	saddr = (uintptr_t)uaddr;
876 	eaddr = (uintptr_t)uaddr + len;
877 
878 	/* verify addresses are valid for userspace */
879 	return ((saddr == eaddr) ||
880 	    (eaddr > saddr && eaddr <= VM_MAXUSER_ADDRESS));
881 }
882 
883 /*
884  * This function should return either EINTR or ERESTART depending on
885  * the signal type sent to this thread:
886  */
887 static int
888 linux_get_error(struct task_struct *task, int error)
889 {
890 	/* check for signal type interrupt code */
891 	if (error == EINTR || error == ERESTARTSYS || error == ERESTART) {
892 		error = -linux_schedule_get_interrupt_value(task);
893 		if (error == 0)
894 			error = EINTR;
895 	}
896 	return (error);
897 }
898 
899 static int
900 linux_file_ioctl_sub(struct file *fp, struct linux_file *filp,
901     const struct file_operations *fop, u_long cmd, caddr_t data,
902     struct thread *td)
903 {
904 	struct task_struct *task = current;
905 	unsigned size;
906 	int error;
907 
908 	size = IOCPARM_LEN(cmd);
909 	/* refer to logic in sys_ioctl() */
910 	if (size > 0) {
911 		/*
912 		 * Setup hint for linux_copyin() and linux_copyout().
913 		 *
914 		 * Background: Linux code expects a user-space address
915 		 * while FreeBSD supplies a kernel-space address.
916 		 */
917 		task->bsd_ioctl_data = data;
918 		task->bsd_ioctl_len = size;
919 		data = (void *)LINUX_IOCTL_MIN_PTR;
920 	} else {
921 		/* fetch user-space pointer */
922 		data = *(void **)data;
923 	}
924 #ifdef COMPAT_FREEBSD32
925 	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
926 		/* try the compat IOCTL handler first */
927 		if (fop->compat_ioctl != NULL) {
928 			error = -OPW(fp, td, fop->compat_ioctl(filp,
929 			    cmd, (u_long)data));
930 		} else {
931 			error = ENOTTY;
932 		}
933 
934 		/* fallback to the regular IOCTL handler, if any */
935 		if (error == ENOTTY && fop->unlocked_ioctl != NULL) {
936 			error = -OPW(fp, td, fop->unlocked_ioctl(filp,
937 			    cmd, (u_long)data));
938 		}
939 	} else
940 #endif
941 	{
942 		if (fop->unlocked_ioctl != NULL) {
943 			error = -OPW(fp, td, fop->unlocked_ioctl(filp,
944 			    cmd, (u_long)data));
945 		} else {
946 			error = ENOTTY;
947 		}
948 	}
949 	if (size > 0) {
950 		task->bsd_ioctl_data = NULL;
951 		task->bsd_ioctl_len = 0;
952 	}
953 
954 	if (error == EWOULDBLOCK) {
955 		/* update kqfilter status, if any */
956 		linux_file_kqfilter_poll(filp,
957 		    LINUX_KQ_FLAG_HAS_READ | LINUX_KQ_FLAG_HAS_WRITE);
958 	} else {
959 		error = linux_get_error(task, error);
960 	}
961 	return (error);
962 }
963 
964 #define	LINUX_POLL_TABLE_NORMAL ((poll_table *)1)
965 
966 /*
967  * This function atomically updates the poll wakeup state and returns
968  * the previous state at the time of update.
969  */
970 static uint8_t
971 linux_poll_wakeup_state(atomic_t *v, const uint8_t *pstate)
972 {
973 	int c, old;
974 
975 	c = v->counter;
976 
977 	while ((old = atomic_cmpxchg(v, c, pstate[c])) != c)
978 		c = old;
979 
980 	return (c);
981 }
982 
983 static int
984 linux_poll_wakeup_callback(wait_queue_t *wq, unsigned int wq_state, int flags, void *key)
985 {
986 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
987 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_INIT, /* NOP */
988 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_NOT_READY, /* NOP */
989 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_READY,
990 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_READY, /* NOP */
991 	};
992 	struct linux_file *filp = container_of(wq, struct linux_file, f_wait_queue.wq);
993 
994 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
995 	case LINUX_FWQ_STATE_QUEUED:
996 		linux_poll_wakeup(filp);
997 		return (1);
998 	default:
999 		return (0);
1000 	}
1001 }
1002 
1003 void
1004 linux_poll_wait(struct linux_file *filp, wait_queue_head_t *wqh, poll_table *p)
1005 {
1006 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1007 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_NOT_READY,
1008 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_NOT_READY, /* NOP */
1009 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_QUEUED, /* NOP */
1010 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_QUEUED,
1011 	};
1012 
1013 	/* check if we are called inside the select system call */
1014 	if (p == LINUX_POLL_TABLE_NORMAL)
1015 		selrecord(curthread, &filp->f_selinfo);
1016 
1017 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1018 	case LINUX_FWQ_STATE_INIT:
1019 		/* NOTE: file handles can only belong to one wait-queue */
1020 		filp->f_wait_queue.wqh = wqh;
1021 		filp->f_wait_queue.wq.func = &linux_poll_wakeup_callback;
1022 		add_wait_queue(wqh, &filp->f_wait_queue.wq);
1023 		atomic_set(&filp->f_wait_queue.state, LINUX_FWQ_STATE_QUEUED);
1024 		break;
1025 	default:
1026 		break;
1027 	}
1028 }
1029 
1030 static void
1031 linux_poll_wait_dequeue(struct linux_file *filp)
1032 {
1033 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1034 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_INIT,	/* NOP */
1035 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_INIT,
1036 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_INIT,
1037 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_INIT,
1038 	};
1039 
1040 	seldrain(&filp->f_selinfo);
1041 
1042 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1043 	case LINUX_FWQ_STATE_NOT_READY:
1044 	case LINUX_FWQ_STATE_QUEUED:
1045 	case LINUX_FWQ_STATE_READY:
1046 		remove_wait_queue(filp->f_wait_queue.wqh, &filp->f_wait_queue.wq);
1047 		break;
1048 	default:
1049 		break;
1050 	}
1051 }
1052 
1053 void
1054 linux_poll_wakeup(struct linux_file *filp)
1055 {
1056 	/* this function should be NULL-safe */
1057 	if (filp == NULL)
1058 		return;
1059 
1060 	selwakeup(&filp->f_selinfo);
1061 
1062 	spin_lock(&filp->f_kqlock);
1063 	filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ |
1064 	    LINUX_KQ_FLAG_NEED_WRITE;
1065 
1066 	/* make sure the "knote" gets woken up */
1067 	KNOTE_LOCKED(&filp->f_selinfo.si_note, 1);
1068 	spin_unlock(&filp->f_kqlock);
1069 }
1070 
1071 static void
1072 linux_file_kqfilter_detach(struct knote *kn)
1073 {
1074 	struct linux_file *filp = kn->kn_hook;
1075 
1076 	spin_lock(&filp->f_kqlock);
1077 	knlist_remove(&filp->f_selinfo.si_note, kn, 1);
1078 	spin_unlock(&filp->f_kqlock);
1079 }
1080 
1081 static int
1082 linux_file_kqfilter_read_event(struct knote *kn, long hint)
1083 {
1084 	struct linux_file *filp = kn->kn_hook;
1085 
1086 	mtx_assert(&filp->f_kqlock.m, MA_OWNED);
1087 
1088 	return ((filp->f_kqflags & LINUX_KQ_FLAG_NEED_READ) ? 1 : 0);
1089 }
1090 
1091 static int
1092 linux_file_kqfilter_write_event(struct knote *kn, long hint)
1093 {
1094 	struct linux_file *filp = kn->kn_hook;
1095 
1096 	mtx_assert(&filp->f_kqlock.m, MA_OWNED);
1097 
1098 	return ((filp->f_kqflags & LINUX_KQ_FLAG_NEED_WRITE) ? 1 : 0);
1099 }
1100 
1101 static struct filterops linux_dev_kqfiltops_read = {
1102 	.f_isfd = 1,
1103 	.f_detach = linux_file_kqfilter_detach,
1104 	.f_event = linux_file_kqfilter_read_event,
1105 };
1106 
1107 static struct filterops linux_dev_kqfiltops_write = {
1108 	.f_isfd = 1,
1109 	.f_detach = linux_file_kqfilter_detach,
1110 	.f_event = linux_file_kqfilter_write_event,
1111 };
1112 
1113 static void
1114 linux_file_kqfilter_poll(struct linux_file *filp, int kqflags)
1115 {
1116 	struct thread *td;
1117 	const struct file_operations *fop;
1118 	struct linux_cdev *ldev;
1119 	int temp;
1120 
1121 	if ((filp->f_kqflags & kqflags) == 0)
1122 		return;
1123 
1124 	td = curthread;
1125 
1126 	linux_get_fop(filp, &fop, &ldev);
1127 	/* get the latest polling state */
1128 	temp = OPW(filp->_file, td, fop->poll(filp, NULL));
1129 	linux_drop_fop(ldev);
1130 
1131 	spin_lock(&filp->f_kqlock);
1132 	/* clear kqflags */
1133 	filp->f_kqflags &= ~(LINUX_KQ_FLAG_NEED_READ |
1134 	    LINUX_KQ_FLAG_NEED_WRITE);
1135 	/* update kqflags */
1136 	if ((temp & (POLLIN | POLLOUT)) != 0) {
1137 		if ((temp & POLLIN) != 0)
1138 			filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ;
1139 		if ((temp & POLLOUT) != 0)
1140 			filp->f_kqflags |= LINUX_KQ_FLAG_NEED_WRITE;
1141 
1142 		/* make sure the "knote" gets woken up */
1143 		KNOTE_LOCKED(&filp->f_selinfo.si_note, 0);
1144 	}
1145 	spin_unlock(&filp->f_kqlock);
1146 }
1147 
1148 static int
1149 linux_file_kqfilter(struct file *file, struct knote *kn)
1150 {
1151 	struct linux_file *filp;
1152 	struct thread *td;
1153 	int error;
1154 
1155 	td = curthread;
1156 	filp = (struct linux_file *)file->f_data;
1157 	filp->f_flags = file->f_flag;
1158 	if (filp->f_op->poll == NULL)
1159 		return (EINVAL);
1160 
1161 	spin_lock(&filp->f_kqlock);
1162 	switch (kn->kn_filter) {
1163 	case EVFILT_READ:
1164 		filp->f_kqflags |= LINUX_KQ_FLAG_HAS_READ;
1165 		kn->kn_fop = &linux_dev_kqfiltops_read;
1166 		kn->kn_hook = filp;
1167 		knlist_add(&filp->f_selinfo.si_note, kn, 1);
1168 		error = 0;
1169 		break;
1170 	case EVFILT_WRITE:
1171 		filp->f_kqflags |= LINUX_KQ_FLAG_HAS_WRITE;
1172 		kn->kn_fop = &linux_dev_kqfiltops_write;
1173 		kn->kn_hook = filp;
1174 		knlist_add(&filp->f_selinfo.si_note, kn, 1);
1175 		error = 0;
1176 		break;
1177 	default:
1178 		error = EINVAL;
1179 		break;
1180 	}
1181 	spin_unlock(&filp->f_kqlock);
1182 
1183 	if (error == 0) {
1184 		linux_set_current(td);
1185 
1186 		/* update kqfilter status, if any */
1187 		linux_file_kqfilter_poll(filp,
1188 		    LINUX_KQ_FLAG_HAS_READ | LINUX_KQ_FLAG_HAS_WRITE);
1189 	}
1190 	return (error);
1191 }
1192 
1193 static int
1194 linux_file_mmap_single(struct file *fp, const struct file_operations *fop,
1195     vm_ooffset_t *offset, vm_size_t size, struct vm_object **object,
1196     int nprot, bool is_shared, struct thread *td)
1197 {
1198 	struct task_struct *task;
1199 	struct vm_area_struct *vmap;
1200 	struct mm_struct *mm;
1201 	struct linux_file *filp;
1202 	vm_memattr_t attr;
1203 	int error;
1204 
1205 	filp = (struct linux_file *)fp->f_data;
1206 	filp->f_flags = fp->f_flag;
1207 
1208 	if (fop->mmap == NULL)
1209 		return (EOPNOTSUPP);
1210 
1211 	linux_set_current(td);
1212 
1213 	/*
1214 	 * The same VM object might be shared by multiple processes
1215 	 * and the mm_struct is usually freed when a process exits.
1216 	 *
1217 	 * The atomic reference below makes sure the mm_struct is
1218 	 * available as long as the vmap is in the linux_vma_head.
1219 	 */
1220 	task = current;
1221 	mm = task->mm;
1222 	if (atomic_inc_not_zero(&mm->mm_users) == 0)
1223 		return (EINVAL);
1224 
1225 	vmap = kzalloc(sizeof(*vmap), GFP_KERNEL);
1226 	vmap->vm_start = 0;
1227 	vmap->vm_end = size;
1228 	vmap->vm_pgoff = *offset / PAGE_SIZE;
1229 	vmap->vm_pfn = 0;
1230 	vmap->vm_flags = vmap->vm_page_prot = (nprot & VM_PROT_ALL);
1231 	if (is_shared)
1232 		vmap->vm_flags |= VM_SHARED;
1233 	vmap->vm_ops = NULL;
1234 	vmap->vm_file = get_file(filp);
1235 	vmap->vm_mm = mm;
1236 
1237 	if (unlikely(down_write_killable(&vmap->vm_mm->mmap_sem))) {
1238 		error = linux_get_error(task, EINTR);
1239 	} else {
1240 		error = -OPW(fp, td, fop->mmap(filp, vmap));
1241 		error = linux_get_error(task, error);
1242 		up_write(&vmap->vm_mm->mmap_sem);
1243 	}
1244 
1245 	if (error != 0) {
1246 		linux_cdev_handle_free(vmap);
1247 		return (error);
1248 	}
1249 
1250 	attr = pgprot2cachemode(vmap->vm_page_prot);
1251 
1252 	if (vmap->vm_ops != NULL) {
1253 		struct vm_area_struct *ptr;
1254 		void *vm_private_data;
1255 		bool vm_no_fault;
1256 
1257 		if (vmap->vm_ops->open == NULL ||
1258 		    vmap->vm_ops->close == NULL ||
1259 		    vmap->vm_private_data == NULL) {
1260 			/* free allocated VM area struct */
1261 			linux_cdev_handle_free(vmap);
1262 			return (EINVAL);
1263 		}
1264 
1265 		vm_private_data = vmap->vm_private_data;
1266 
1267 		rw_wlock(&linux_vma_lock);
1268 		TAILQ_FOREACH(ptr, &linux_vma_head, vm_entry) {
1269 			if (ptr->vm_private_data == vm_private_data)
1270 				break;
1271 		}
1272 		/* check if there is an existing VM area struct */
1273 		if (ptr != NULL) {
1274 			/* check if the VM area structure is invalid */
1275 			if (ptr->vm_ops == NULL ||
1276 			    ptr->vm_ops->open == NULL ||
1277 			    ptr->vm_ops->close == NULL) {
1278 				error = ESTALE;
1279 				vm_no_fault = 1;
1280 			} else {
1281 				error = EEXIST;
1282 				vm_no_fault = (ptr->vm_ops->fault == NULL);
1283 			}
1284 		} else {
1285 			/* insert VM area structure into list */
1286 			TAILQ_INSERT_TAIL(&linux_vma_head, vmap, vm_entry);
1287 			error = 0;
1288 			vm_no_fault = (vmap->vm_ops->fault == NULL);
1289 		}
1290 		rw_wunlock(&linux_vma_lock);
1291 
1292 		if (error != 0) {
1293 			/* free allocated VM area struct */
1294 			linux_cdev_handle_free(vmap);
1295 			/* check for stale VM area struct */
1296 			if (error != EEXIST)
1297 				return (error);
1298 		}
1299 
1300 		/* check if there is no fault handler */
1301 		if (vm_no_fault) {
1302 			*object = cdev_pager_allocate(vm_private_data, OBJT_DEVICE,
1303 			    &linux_cdev_pager_ops[1], size, nprot, *offset,
1304 			    td->td_ucred);
1305 		} else {
1306 			*object = cdev_pager_allocate(vm_private_data, OBJT_MGTDEVICE,
1307 			    &linux_cdev_pager_ops[0], size, nprot, *offset,
1308 			    td->td_ucred);
1309 		}
1310 
1311 		/* check if allocating the VM object failed */
1312 		if (*object == NULL) {
1313 			if (error == 0) {
1314 				/* remove VM area struct from list */
1315 				linux_cdev_handle_remove(vmap);
1316 				/* free allocated VM area struct */
1317 				linux_cdev_handle_free(vmap);
1318 			}
1319 			return (EINVAL);
1320 		}
1321 	} else {
1322 		struct sglist *sg;
1323 
1324 		sg = sglist_alloc(1, M_WAITOK);
1325 		sglist_append_phys(sg,
1326 		    (vm_paddr_t)vmap->vm_pfn << PAGE_SHIFT, vmap->vm_len);
1327 
1328 		*object = vm_pager_allocate(OBJT_SG, sg, vmap->vm_len,
1329 		    nprot, 0, td->td_ucred);
1330 
1331 		linux_cdev_handle_free(vmap);
1332 
1333 		if (*object == NULL) {
1334 			sglist_free(sg);
1335 			return (EINVAL);
1336 		}
1337 	}
1338 
1339 	if (attr != VM_MEMATTR_DEFAULT) {
1340 		VM_OBJECT_WLOCK(*object);
1341 		vm_object_set_memattr(*object, attr);
1342 		VM_OBJECT_WUNLOCK(*object);
1343 	}
1344 	*offset = 0;
1345 	return (0);
1346 }
1347 
1348 struct cdevsw linuxcdevsw = {
1349 	.d_version = D_VERSION,
1350 	.d_fdopen = linux_dev_fdopen,
1351 	.d_name = "lkpidev",
1352 };
1353 
1354 static int
1355 linux_file_read(struct file *file, struct uio *uio, struct ucred *active_cred,
1356     int flags, struct thread *td)
1357 {
1358 	struct linux_file *filp;
1359 	const struct file_operations *fop;
1360 	struct linux_cdev *ldev;
1361 	ssize_t bytes;
1362 	int error;
1363 
1364 	error = 0;
1365 	filp = (struct linux_file *)file->f_data;
1366 	filp->f_flags = file->f_flag;
1367 	/* XXX no support for I/O vectors currently */
1368 	if (uio->uio_iovcnt != 1)
1369 		return (EOPNOTSUPP);
1370 	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1371 		return (EINVAL);
1372 	linux_set_current(td);
1373 	linux_get_fop(filp, &fop, &ldev);
1374 	if (fop->read != NULL) {
1375 		bytes = OPW(file, td, fop->read(filp,
1376 		    uio->uio_iov->iov_base,
1377 		    uio->uio_iov->iov_len, &uio->uio_offset));
1378 		if (bytes >= 0) {
1379 			uio->uio_iov->iov_base =
1380 			    ((uint8_t *)uio->uio_iov->iov_base) + bytes;
1381 			uio->uio_iov->iov_len -= bytes;
1382 			uio->uio_resid -= bytes;
1383 		} else {
1384 			error = linux_get_error(current, -bytes);
1385 		}
1386 	} else
1387 		error = ENXIO;
1388 
1389 	/* update kqfilter status, if any */
1390 	linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_READ);
1391 	linux_drop_fop(ldev);
1392 
1393 	return (error);
1394 }
1395 
1396 static int
1397 linux_file_write(struct file *file, struct uio *uio, struct ucred *active_cred,
1398     int flags, struct thread *td)
1399 {
1400 	struct linux_file *filp;
1401 	const struct file_operations *fop;
1402 	struct linux_cdev *ldev;
1403 	ssize_t bytes;
1404 	int error;
1405 
1406 	filp = (struct linux_file *)file->f_data;
1407 	filp->f_flags = file->f_flag;
1408 	/* XXX no support for I/O vectors currently */
1409 	if (uio->uio_iovcnt != 1)
1410 		return (EOPNOTSUPP);
1411 	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1412 		return (EINVAL);
1413 	linux_set_current(td);
1414 	linux_get_fop(filp, &fop, &ldev);
1415 	if (fop->write != NULL) {
1416 		bytes = OPW(file, td, fop->write(filp,
1417 		    uio->uio_iov->iov_base,
1418 		    uio->uio_iov->iov_len, &uio->uio_offset));
1419 		if (bytes >= 0) {
1420 			uio->uio_iov->iov_base =
1421 			    ((uint8_t *)uio->uio_iov->iov_base) + bytes;
1422 			uio->uio_iov->iov_len -= bytes;
1423 			uio->uio_resid -= bytes;
1424 			error = 0;
1425 		} else {
1426 			error = linux_get_error(current, -bytes);
1427 		}
1428 	} else
1429 		error = ENXIO;
1430 
1431 	/* update kqfilter status, if any */
1432 	linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_WRITE);
1433 
1434 	linux_drop_fop(ldev);
1435 
1436 	return (error);
1437 }
1438 
1439 static int
1440 linux_file_poll(struct file *file, int events, struct ucred *active_cred,
1441     struct thread *td)
1442 {
1443 	struct linux_file *filp;
1444 	const struct file_operations *fop;
1445 	struct linux_cdev *ldev;
1446 	int revents;
1447 
1448 	filp = (struct linux_file *)file->f_data;
1449 	filp->f_flags = file->f_flag;
1450 	linux_set_current(td);
1451 	linux_get_fop(filp, &fop, &ldev);
1452 	if (fop->poll != NULL) {
1453 		revents = OPW(file, td, fop->poll(filp,
1454 		    LINUX_POLL_TABLE_NORMAL)) & events;
1455 	} else {
1456 		revents = 0;
1457 	}
1458 	linux_drop_fop(ldev);
1459 	return (revents);
1460 }
1461 
1462 static int
1463 linux_file_close(struct file *file, struct thread *td)
1464 {
1465 	struct linux_file *filp;
1466 	int (*release)(struct inode *, struct linux_file *);
1467 	const struct file_operations *fop;
1468 	struct linux_cdev *ldev;
1469 	int error;
1470 
1471 	filp = (struct linux_file *)file->f_data;
1472 
1473 	KASSERT(file_count(filp) == 0,
1474 	    ("File refcount(%d) is not zero", file_count(filp)));
1475 
1476 	if (td == NULL)
1477 		td = curthread;
1478 
1479 	error = 0;
1480 	filp->f_flags = file->f_flag;
1481 	linux_set_current(td);
1482 	linux_poll_wait_dequeue(filp);
1483 	linux_get_fop(filp, &fop, &ldev);
1484 	/*
1485 	 * Always use the real release function, if any, to avoid
1486 	 * leaking device resources:
1487 	 */
1488 	release = filp->f_op->release;
1489 	if (release != NULL)
1490 		error = -OPW(file, td, release(filp->f_vnode, filp));
1491 	funsetown(&filp->f_sigio);
1492 	if (filp->f_vnode != NULL)
1493 		vdrop(filp->f_vnode);
1494 	linux_drop_fop(ldev);
1495 	ldev = filp->f_cdev;
1496 	if (ldev != NULL)
1497 		linux_cdev_deref(ldev);
1498 	linux_synchronize_rcu(RCU_TYPE_REGULAR);
1499 	kfree(filp);
1500 
1501 	return (error);
1502 }
1503 
1504 static int
1505 linux_file_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *cred,
1506     struct thread *td)
1507 {
1508 	struct linux_file *filp;
1509 	const struct file_operations *fop;
1510 	struct linux_cdev *ldev;
1511 	struct fiodgname_arg *fgn;
1512 	const char *p;
1513 	int error, i;
1514 
1515 	error = 0;
1516 	filp = (struct linux_file *)fp->f_data;
1517 	filp->f_flags = fp->f_flag;
1518 	linux_get_fop(filp, &fop, &ldev);
1519 
1520 	linux_set_current(td);
1521 	switch (cmd) {
1522 	case FIONBIO:
1523 		break;
1524 	case FIOASYNC:
1525 		if (fop->fasync == NULL)
1526 			break;
1527 		error = -OPW(fp, td, fop->fasync(0, filp, fp->f_flag & FASYNC));
1528 		break;
1529 	case FIOSETOWN:
1530 		error = fsetown(*(int *)data, &filp->f_sigio);
1531 		if (error == 0) {
1532 			if (fop->fasync == NULL)
1533 				break;
1534 			error = -OPW(fp, td, fop->fasync(0, filp,
1535 			    fp->f_flag & FASYNC));
1536 		}
1537 		break;
1538 	case FIOGETOWN:
1539 		*(int *)data = fgetown(&filp->f_sigio);
1540 		break;
1541 	case FIODGNAME:
1542 #ifdef	COMPAT_FREEBSD32
1543 	case FIODGNAME_32:
1544 #endif
1545 		if (filp->f_cdev == NULL || filp->f_cdev->cdev == NULL) {
1546 			error = ENXIO;
1547 			break;
1548 		}
1549 		fgn = data;
1550 		p = devtoname(filp->f_cdev->cdev);
1551 		i = strlen(p) + 1;
1552 		if (i > fgn->len) {
1553 			error = EINVAL;
1554 			break;
1555 		}
1556 		error = copyout(p, fiodgname_buf_get_ptr(fgn, cmd), i);
1557 		break;
1558 	default:
1559 		error = linux_file_ioctl_sub(fp, filp, fop, cmd, data, td);
1560 		break;
1561 	}
1562 	linux_drop_fop(ldev);
1563 	return (error);
1564 }
1565 
1566 static int
1567 linux_file_mmap_sub(struct thread *td, vm_size_t objsize, vm_prot_t prot,
1568     vm_prot_t maxprot, int flags, struct file *fp,
1569     vm_ooffset_t *foff, const struct file_operations *fop, vm_object_t *objp)
1570 {
1571 	/*
1572 	 * Character devices do not provide private mappings
1573 	 * of any kind:
1574 	 */
1575 	if ((maxprot & VM_PROT_WRITE) == 0 &&
1576 	    (prot & VM_PROT_WRITE) != 0)
1577 		return (EACCES);
1578 	if ((flags & (MAP_PRIVATE | MAP_COPY)) != 0)
1579 		return (EINVAL);
1580 
1581 	return (linux_file_mmap_single(fp, fop, foff, objsize, objp,
1582 	    (int)prot, (flags & MAP_SHARED) ? true : false, td));
1583 }
1584 
1585 static int
1586 linux_file_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
1587     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
1588     struct thread *td)
1589 {
1590 	struct linux_file *filp;
1591 	const struct file_operations *fop;
1592 	struct linux_cdev *ldev;
1593 	struct mount *mp;
1594 	struct vnode *vp;
1595 	vm_object_t object;
1596 	vm_prot_t maxprot;
1597 	int error;
1598 
1599 	filp = (struct linux_file *)fp->f_data;
1600 
1601 	vp = filp->f_vnode;
1602 	if (vp == NULL)
1603 		return (EOPNOTSUPP);
1604 
1605 	/*
1606 	 * Ensure that file and memory protections are
1607 	 * compatible.
1608 	 */
1609 	mp = vp->v_mount;
1610 	if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
1611 		maxprot = VM_PROT_NONE;
1612 		if ((prot & VM_PROT_EXECUTE) != 0)
1613 			return (EACCES);
1614 	} else
1615 		maxprot = VM_PROT_EXECUTE;
1616 	if ((fp->f_flag & FREAD) != 0)
1617 		maxprot |= VM_PROT_READ;
1618 	else if ((prot & VM_PROT_READ) != 0)
1619 		return (EACCES);
1620 
1621 	/*
1622 	 * If we are sharing potential changes via MAP_SHARED and we
1623 	 * are trying to get write permission although we opened it
1624 	 * without asking for it, bail out.
1625 	 *
1626 	 * Note that most character devices always share mappings.
1627 	 *
1628 	 * Rely on linux_file_mmap_sub() to fail invalid MAP_PRIVATE
1629 	 * requests rather than doing it here.
1630 	 */
1631 	if ((flags & MAP_SHARED) != 0) {
1632 		if ((fp->f_flag & FWRITE) != 0)
1633 			maxprot |= VM_PROT_WRITE;
1634 		else if ((prot & VM_PROT_WRITE) != 0)
1635 			return (EACCES);
1636 	}
1637 	maxprot &= cap_maxprot;
1638 
1639 	linux_get_fop(filp, &fop, &ldev);
1640 	error = linux_file_mmap_sub(td, size, prot, maxprot, flags, fp,
1641 	    &foff, fop, &object);
1642 	if (error != 0)
1643 		goto out;
1644 
1645 	error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
1646 	    foff, FALSE, td);
1647 	if (error != 0)
1648 		vm_object_deallocate(object);
1649 out:
1650 	linux_drop_fop(ldev);
1651 	return (error);
1652 }
1653 
1654 static int
1655 linux_file_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
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 = VOP_STAT(vp, sb, curthread->td_ucred, NOCRED);
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__) || defined(__riscv)
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__) || defined(__riscv)
1803 	pmap_unmapdev(addr, vmmap->vm_size);
1804 #endif
1805 	kfree(vmmap);
1806 }
1807 
1808 void *
1809 vmap(struct page **pages, unsigned int count, unsigned long flags, int prot)
1810 {
1811 	vm_offset_t off;
1812 	size_t size;
1813 
1814 	size = count * PAGE_SIZE;
1815 	off = kva_alloc(size);
1816 	if (off == 0)
1817 		return (NULL);
1818 	vmmap_add((void *)off, size);
1819 	pmap_qenter(off, pages, count);
1820 
1821 	return ((void *)off);
1822 }
1823 
1824 void
1825 vunmap(void *addr)
1826 {
1827 	struct vmmap *vmmap;
1828 
1829 	vmmap = vmmap_remove(addr);
1830 	if (vmmap == NULL)
1831 		return;
1832 	pmap_qremove((vm_offset_t)addr, vmmap->vm_size / PAGE_SIZE);
1833 	kva_free((vm_offset_t)addr, vmmap->vm_size);
1834 	kfree(vmmap);
1835 }
1836 
1837 static char *
1838 devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt, va_list ap)
1839 {
1840 	unsigned int len;
1841 	char *p;
1842 	va_list aq;
1843 
1844 	va_copy(aq, ap);
1845 	len = vsnprintf(NULL, 0, fmt, aq);
1846 	va_end(aq);
1847 
1848 	if (dev != NULL)
1849 		p = devm_kmalloc(dev, len + 1, gfp);
1850 	else
1851 		p = kmalloc(len + 1, gfp);
1852 	if (p != NULL)
1853 		vsnprintf(p, len + 1, fmt, ap);
1854 
1855 	return (p);
1856 }
1857 
1858 char *
1859 kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
1860 {
1861 
1862 	return (devm_kvasprintf(NULL, gfp, fmt, ap));
1863 }
1864 
1865 char *
1866 lkpi_devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
1867 {
1868 	va_list ap;
1869 	char *p;
1870 
1871 	va_start(ap, fmt);
1872 	p = devm_kvasprintf(dev, gfp, fmt, ap);
1873 	va_end(ap);
1874 
1875 	return (p);
1876 }
1877 
1878 char *
1879 kasprintf(gfp_t gfp, const char *fmt, ...)
1880 {
1881 	va_list ap;
1882 	char *p;
1883 
1884 	va_start(ap, fmt);
1885 	p = kvasprintf(gfp, fmt, ap);
1886 	va_end(ap);
1887 
1888 	return (p);
1889 }
1890 
1891 static void
1892 linux_timer_callback_wrapper(void *context)
1893 {
1894 	struct timer_list *timer;
1895 
1896 	timer = context;
1897 
1898 	if (linux_set_current_flags(curthread, M_NOWAIT)) {
1899 		/* try again later */
1900 		callout_reset(&timer->callout, 1,
1901 		    &linux_timer_callback_wrapper, timer);
1902 		return;
1903 	}
1904 
1905 	timer->function(timer->data);
1906 }
1907 
1908 int
1909 mod_timer(struct timer_list *timer, int expires)
1910 {
1911 	int ret;
1912 
1913 	timer->expires = expires;
1914 	ret = callout_reset(&timer->callout,
1915 	    linux_timer_jiffies_until(expires),
1916 	    &linux_timer_callback_wrapper, timer);
1917 
1918 	MPASS(ret == 0 || ret == 1);
1919 
1920 	return (ret == 1);
1921 }
1922 
1923 void
1924 add_timer(struct timer_list *timer)
1925 {
1926 
1927 	callout_reset(&timer->callout,
1928 	    linux_timer_jiffies_until(timer->expires),
1929 	    &linux_timer_callback_wrapper, timer);
1930 }
1931 
1932 void
1933 add_timer_on(struct timer_list *timer, int cpu)
1934 {
1935 
1936 	callout_reset_on(&timer->callout,
1937 	    linux_timer_jiffies_until(timer->expires),
1938 	    &linux_timer_callback_wrapper, timer, cpu);
1939 }
1940 
1941 int
1942 del_timer(struct timer_list *timer)
1943 {
1944 
1945 	if (callout_stop(&(timer)->callout) == -1)
1946 		return (0);
1947 	return (1);
1948 }
1949 
1950 int
1951 del_timer_sync(struct timer_list *timer)
1952 {
1953 
1954 	if (callout_drain(&(timer)->callout) == -1)
1955 		return (0);
1956 	return (1);
1957 }
1958 
1959 int
1960 timer_delete_sync(struct timer_list *timer)
1961 {
1962 
1963 	return (del_timer_sync(timer));
1964 }
1965 
1966 int
1967 timer_shutdown_sync(struct timer_list *timer)
1968 {
1969 
1970 	return (del_timer_sync(timer));
1971 }
1972 
1973 /* greatest common divisor, Euclid equation */
1974 static uint64_t
1975 lkpi_gcd_64(uint64_t a, uint64_t b)
1976 {
1977 	uint64_t an;
1978 	uint64_t bn;
1979 
1980 	while (b != 0) {
1981 		an = b;
1982 		bn = a % b;
1983 		a = an;
1984 		b = bn;
1985 	}
1986 	return (a);
1987 }
1988 
1989 uint64_t lkpi_nsec2hz_rem;
1990 uint64_t lkpi_nsec2hz_div = 1000000000ULL;
1991 uint64_t lkpi_nsec2hz_max;
1992 
1993 uint64_t lkpi_usec2hz_rem;
1994 uint64_t lkpi_usec2hz_div = 1000000ULL;
1995 uint64_t lkpi_usec2hz_max;
1996 
1997 uint64_t lkpi_msec2hz_rem;
1998 uint64_t lkpi_msec2hz_div = 1000ULL;
1999 uint64_t lkpi_msec2hz_max;
2000 
2001 static void
2002 linux_timer_init(void *arg)
2003 {
2004 	uint64_t gcd;
2005 
2006 	/*
2007 	 * Compute an internal HZ value which can divide 2**32 to
2008 	 * avoid timer rounding problems when the tick value wraps
2009 	 * around 2**32:
2010 	 */
2011 	linux_timer_hz_mask = 1;
2012 	while (linux_timer_hz_mask < (unsigned long)hz)
2013 		linux_timer_hz_mask *= 2;
2014 	linux_timer_hz_mask--;
2015 
2016 	/* compute some internal constants */
2017 
2018 	lkpi_nsec2hz_rem = hz;
2019 	lkpi_usec2hz_rem = hz;
2020 	lkpi_msec2hz_rem = hz;
2021 
2022 	gcd = lkpi_gcd_64(lkpi_nsec2hz_rem, lkpi_nsec2hz_div);
2023 	lkpi_nsec2hz_rem /= gcd;
2024 	lkpi_nsec2hz_div /= gcd;
2025 	lkpi_nsec2hz_max = -1ULL / lkpi_nsec2hz_rem;
2026 
2027 	gcd = lkpi_gcd_64(lkpi_usec2hz_rem, lkpi_usec2hz_div);
2028 	lkpi_usec2hz_rem /= gcd;
2029 	lkpi_usec2hz_div /= gcd;
2030 	lkpi_usec2hz_max = -1ULL / lkpi_usec2hz_rem;
2031 
2032 	gcd = lkpi_gcd_64(lkpi_msec2hz_rem, lkpi_msec2hz_div);
2033 	lkpi_msec2hz_rem /= gcd;
2034 	lkpi_msec2hz_div /= gcd;
2035 	lkpi_msec2hz_max = -1ULL / lkpi_msec2hz_rem;
2036 }
2037 SYSINIT(linux_timer, SI_SUB_DRIVERS, SI_ORDER_FIRST, linux_timer_init, NULL);
2038 
2039 void
2040 linux_complete_common(struct completion *c, int all)
2041 {
2042 	int wakeup_swapper;
2043 
2044 	sleepq_lock(c);
2045 	if (all) {
2046 		c->done = UINT_MAX;
2047 		wakeup_swapper = sleepq_broadcast(c, SLEEPQ_SLEEP, 0, 0);
2048 	} else {
2049 		if (c->done != UINT_MAX)
2050 			c->done++;
2051 		wakeup_swapper = sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);
2052 	}
2053 	sleepq_release(c);
2054 	if (wakeup_swapper)
2055 		kick_proc0();
2056 }
2057 
2058 /*
2059  * Indefinite wait for done != 0 with or without signals.
2060  */
2061 int
2062 linux_wait_for_common(struct completion *c, int flags)
2063 {
2064 	struct task_struct *task;
2065 	int error;
2066 
2067 	if (SCHEDULER_STOPPED())
2068 		return (0);
2069 
2070 	task = current;
2071 
2072 	if (flags != 0)
2073 		flags = SLEEPQ_INTERRUPTIBLE | SLEEPQ_SLEEP;
2074 	else
2075 		flags = SLEEPQ_SLEEP;
2076 	error = 0;
2077 	for (;;) {
2078 		sleepq_lock(c);
2079 		if (c->done)
2080 			break;
2081 		sleepq_add(c, NULL, "completion", flags, 0);
2082 		if (flags & SLEEPQ_INTERRUPTIBLE) {
2083 			DROP_GIANT();
2084 			error = -sleepq_wait_sig(c, 0);
2085 			PICKUP_GIANT();
2086 			if (error != 0) {
2087 				linux_schedule_save_interrupt_value(task, error);
2088 				error = -ERESTARTSYS;
2089 				goto intr;
2090 			}
2091 		} else {
2092 			DROP_GIANT();
2093 			sleepq_wait(c, 0);
2094 			PICKUP_GIANT();
2095 		}
2096 	}
2097 	if (c->done != UINT_MAX)
2098 		c->done--;
2099 	sleepq_release(c);
2100 
2101 intr:
2102 	return (error);
2103 }
2104 
2105 /*
2106  * Time limited wait for done != 0 with or without signals.
2107  */
2108 int
2109 linux_wait_for_timeout_common(struct completion *c, int timeout, int flags)
2110 {
2111 	struct task_struct *task;
2112 	int end = jiffies + timeout;
2113 	int error;
2114 
2115 	if (SCHEDULER_STOPPED())
2116 		return (0);
2117 
2118 	task = current;
2119 
2120 	if (flags != 0)
2121 		flags = SLEEPQ_INTERRUPTIBLE | SLEEPQ_SLEEP;
2122 	else
2123 		flags = SLEEPQ_SLEEP;
2124 
2125 	for (;;) {
2126 		sleepq_lock(c);
2127 		if (c->done)
2128 			break;
2129 		sleepq_add(c, NULL, "completion", flags, 0);
2130 		sleepq_set_timeout(c, linux_timer_jiffies_until(end));
2131 
2132 		DROP_GIANT();
2133 		if (flags & SLEEPQ_INTERRUPTIBLE)
2134 			error = -sleepq_timedwait_sig(c, 0);
2135 		else
2136 			error = -sleepq_timedwait(c, 0);
2137 		PICKUP_GIANT();
2138 
2139 		if (error != 0) {
2140 			/* check for timeout */
2141 			if (error == -EWOULDBLOCK) {
2142 				error = 0;	/* timeout */
2143 			} else {
2144 				/* signal happened */
2145 				linux_schedule_save_interrupt_value(task, error);
2146 				error = -ERESTARTSYS;
2147 			}
2148 			goto done;
2149 		}
2150 	}
2151 	if (c->done != UINT_MAX)
2152 		c->done--;
2153 	sleepq_release(c);
2154 
2155 	/* return how many jiffies are left */
2156 	error = linux_timer_jiffies_until(end);
2157 done:
2158 	return (error);
2159 }
2160 
2161 int
2162 linux_try_wait_for_completion(struct completion *c)
2163 {
2164 	int isdone;
2165 
2166 	sleepq_lock(c);
2167 	isdone = (c->done != 0);
2168 	if (c->done != 0 && c->done != UINT_MAX)
2169 		c->done--;
2170 	sleepq_release(c);
2171 	return (isdone);
2172 }
2173 
2174 int
2175 linux_completion_done(struct completion *c)
2176 {
2177 	int isdone;
2178 
2179 	sleepq_lock(c);
2180 	isdone = (c->done != 0);
2181 	sleepq_release(c);
2182 	return (isdone);
2183 }
2184 
2185 static void
2186 linux_cdev_deref(struct linux_cdev *ldev)
2187 {
2188 	if (refcount_release(&ldev->refs) &&
2189 	    ldev->kobj.ktype == &linux_cdev_ktype)
2190 		kfree(ldev);
2191 }
2192 
2193 static void
2194 linux_cdev_release(struct kobject *kobj)
2195 {
2196 	struct linux_cdev *cdev;
2197 	struct kobject *parent;
2198 
2199 	cdev = container_of(kobj, struct linux_cdev, kobj);
2200 	parent = kobj->parent;
2201 	linux_destroy_dev(cdev);
2202 	linux_cdev_deref(cdev);
2203 	kobject_put(parent);
2204 }
2205 
2206 static void
2207 linux_cdev_static_release(struct kobject *kobj)
2208 {
2209 	struct cdev *cdev;
2210 	struct linux_cdev *ldev;
2211 
2212 	ldev = container_of(kobj, struct linux_cdev, kobj);
2213 	cdev = ldev->cdev;
2214 	if (cdev != NULL) {
2215 		destroy_dev(cdev);
2216 		ldev->cdev = NULL;
2217 	}
2218 	kobject_put(kobj->parent);
2219 }
2220 
2221 int
2222 linux_cdev_device_add(struct linux_cdev *ldev, struct device *dev)
2223 {
2224 	int ret;
2225 
2226 	if (dev->devt != 0) {
2227 		/* Set parent kernel object. */
2228 		ldev->kobj.parent = &dev->kobj;
2229 
2230 		/*
2231 		 * Unlike Linux we require the kobject of the
2232 		 * character device structure to have a valid name
2233 		 * before calling this function:
2234 		 */
2235 		if (ldev->kobj.name == NULL)
2236 			return (-EINVAL);
2237 
2238 		ret = cdev_add(ldev, dev->devt, 1);
2239 		if (ret)
2240 			return (ret);
2241 	}
2242 	ret = device_add(dev);
2243 	if (ret != 0 && dev->devt != 0)
2244 		cdev_del(ldev);
2245 	return (ret);
2246 }
2247 
2248 void
2249 linux_cdev_device_del(struct linux_cdev *ldev, struct device *dev)
2250 {
2251 	device_del(dev);
2252 
2253 	if (dev->devt != 0)
2254 		cdev_del(ldev);
2255 }
2256 
2257 static void
2258 linux_destroy_dev(struct linux_cdev *ldev)
2259 {
2260 
2261 	if (ldev->cdev == NULL)
2262 		return;
2263 
2264 	MPASS((ldev->siref & LDEV_SI_DTR) == 0);
2265 	MPASS(ldev->kobj.ktype == &linux_cdev_ktype);
2266 
2267 	atomic_set_int(&ldev->siref, LDEV_SI_DTR);
2268 	while ((atomic_load_int(&ldev->siref) & ~LDEV_SI_DTR) != 0)
2269 		pause("ldevdtr", hz / 4);
2270 
2271 	destroy_dev(ldev->cdev);
2272 	ldev->cdev = NULL;
2273 }
2274 
2275 const struct kobj_type linux_cdev_ktype = {
2276 	.release = linux_cdev_release,
2277 };
2278 
2279 const struct kobj_type linux_cdev_static_ktype = {
2280 	.release = linux_cdev_static_release,
2281 };
2282 
2283 static void
2284 linux_handle_ifnet_link_event(void *arg, struct ifnet *ifp, int linkstate)
2285 {
2286 	struct notifier_block *nb;
2287 	struct netdev_notifier_info ni;
2288 
2289 	nb = arg;
2290 	ni.ifp = ifp;
2291 	ni.dev = (struct net_device *)ifp;
2292 	if (linkstate == LINK_STATE_UP)
2293 		nb->notifier_call(nb, NETDEV_UP, &ni);
2294 	else
2295 		nb->notifier_call(nb, NETDEV_DOWN, &ni);
2296 }
2297 
2298 static void
2299 linux_handle_ifnet_arrival_event(void *arg, struct ifnet *ifp)
2300 {
2301 	struct notifier_block *nb;
2302 	struct netdev_notifier_info ni;
2303 
2304 	nb = arg;
2305 	ni.ifp = ifp;
2306 	ni.dev = (struct net_device *)ifp;
2307 	nb->notifier_call(nb, NETDEV_REGISTER, &ni);
2308 }
2309 
2310 static void
2311 linux_handle_ifnet_departure_event(void *arg, struct ifnet *ifp)
2312 {
2313 	struct notifier_block *nb;
2314 	struct netdev_notifier_info ni;
2315 
2316 	nb = arg;
2317 	ni.ifp = ifp;
2318 	ni.dev = (struct net_device *)ifp;
2319 	nb->notifier_call(nb, NETDEV_UNREGISTER, &ni);
2320 }
2321 
2322 static void
2323 linux_handle_iflladdr_event(void *arg, struct ifnet *ifp)
2324 {
2325 	struct notifier_block *nb;
2326 	struct netdev_notifier_info ni;
2327 
2328 	nb = arg;
2329 	ni.ifp = ifp;
2330 	ni.dev = (struct net_device *)ifp;
2331 	nb->notifier_call(nb, NETDEV_CHANGEADDR, &ni);
2332 }
2333 
2334 static void
2335 linux_handle_ifaddr_event(void *arg, struct ifnet *ifp)
2336 {
2337 	struct notifier_block *nb;
2338 	struct netdev_notifier_info ni;
2339 
2340 	nb = arg;
2341 	ni.ifp = ifp;
2342 	ni.dev = (struct net_device *)ifp;
2343 	nb->notifier_call(nb, NETDEV_CHANGEIFADDR, &ni);
2344 }
2345 
2346 int
2347 register_netdevice_notifier(struct notifier_block *nb)
2348 {
2349 
2350 	nb->tags[NETDEV_UP] = EVENTHANDLER_REGISTER(
2351 	    ifnet_link_event, linux_handle_ifnet_link_event, nb, 0);
2352 	nb->tags[NETDEV_REGISTER] = EVENTHANDLER_REGISTER(
2353 	    ifnet_arrival_event, linux_handle_ifnet_arrival_event, nb, 0);
2354 	nb->tags[NETDEV_UNREGISTER] = EVENTHANDLER_REGISTER(
2355 	    ifnet_departure_event, linux_handle_ifnet_departure_event, nb, 0);
2356 	nb->tags[NETDEV_CHANGEADDR] = EVENTHANDLER_REGISTER(
2357 	    iflladdr_event, linux_handle_iflladdr_event, nb, 0);
2358 
2359 	return (0);
2360 }
2361 
2362 int
2363 register_inetaddr_notifier(struct notifier_block *nb)
2364 {
2365 
2366 	nb->tags[NETDEV_CHANGEIFADDR] = EVENTHANDLER_REGISTER(
2367 	    ifaddr_event, linux_handle_ifaddr_event, nb, 0);
2368 	return (0);
2369 }
2370 
2371 int
2372 unregister_netdevice_notifier(struct notifier_block *nb)
2373 {
2374 
2375 	EVENTHANDLER_DEREGISTER(ifnet_link_event,
2376 	    nb->tags[NETDEV_UP]);
2377 	EVENTHANDLER_DEREGISTER(ifnet_arrival_event,
2378 	    nb->tags[NETDEV_REGISTER]);
2379 	EVENTHANDLER_DEREGISTER(ifnet_departure_event,
2380 	    nb->tags[NETDEV_UNREGISTER]);
2381 	EVENTHANDLER_DEREGISTER(iflladdr_event,
2382 	    nb->tags[NETDEV_CHANGEADDR]);
2383 
2384 	return (0);
2385 }
2386 
2387 int
2388 unregister_inetaddr_notifier(struct notifier_block *nb)
2389 {
2390 
2391 	EVENTHANDLER_DEREGISTER(ifaddr_event,
2392 	    nb->tags[NETDEV_CHANGEIFADDR]);
2393 
2394 	return (0);
2395 }
2396 
2397 struct list_sort_thunk {
2398 	int (*cmp)(void *, struct list_head *, struct list_head *);
2399 	void *priv;
2400 };
2401 
2402 static inline int
2403 linux_le_cmp(const void *d1, const void *d2, void *priv)
2404 {
2405 	struct list_head *le1, *le2;
2406 	struct list_sort_thunk *thunk;
2407 
2408 	thunk = priv;
2409 	le1 = *(__DECONST(struct list_head **, d1));
2410 	le2 = *(__DECONST(struct list_head **, d2));
2411 	return ((thunk->cmp)(thunk->priv, le1, le2));
2412 }
2413 
2414 void
2415 list_sort(void *priv, struct list_head *head, int (*cmp)(void *priv,
2416     struct list_head *a, struct list_head *b))
2417 {
2418 	struct list_sort_thunk thunk;
2419 	struct list_head **ar, *le;
2420 	size_t count, i;
2421 
2422 	count = 0;
2423 	list_for_each(le, head)
2424 		count++;
2425 	ar = malloc(sizeof(struct list_head *) * count, M_KMALLOC, M_WAITOK);
2426 	i = 0;
2427 	list_for_each(le, head)
2428 		ar[i++] = le;
2429 	thunk.cmp = cmp;
2430 	thunk.priv = priv;
2431 	qsort_r(ar, count, sizeof(struct list_head *), linux_le_cmp, &thunk);
2432 	INIT_LIST_HEAD(head);
2433 	for (i = 0; i < count; i++)
2434 		list_add_tail(ar[i], head);
2435 	free(ar, M_KMALLOC);
2436 }
2437 
2438 #if defined(__i386__) || defined(__amd64__)
2439 int
2440 linux_wbinvd_on_all_cpus(void)
2441 {
2442 
2443 	pmap_invalidate_cache();
2444 	return (0);
2445 }
2446 #endif
2447 
2448 int
2449 linux_on_each_cpu(void callback(void *), void *data)
2450 {
2451 
2452 	smp_rendezvous(smp_no_rendezvous_barrier, callback,
2453 	    smp_no_rendezvous_barrier, data);
2454 	return (0);
2455 }
2456 
2457 int
2458 linux_in_atomic(void)
2459 {
2460 
2461 	return ((curthread->td_pflags & TDP_NOFAULTING) != 0);
2462 }
2463 
2464 struct linux_cdev *
2465 linux_find_cdev(const char *name, unsigned major, unsigned minor)
2466 {
2467 	dev_t dev = MKDEV(major, minor);
2468 	struct cdev *cdev;
2469 
2470 	dev_lock();
2471 	LIST_FOREACH(cdev, &linuxcdevsw.d_devs, si_list) {
2472 		struct linux_cdev *ldev = cdev->si_drv1;
2473 		if (ldev->dev == dev &&
2474 		    strcmp(kobject_name(&ldev->kobj), name) == 0) {
2475 			break;
2476 		}
2477 	}
2478 	dev_unlock();
2479 
2480 	return (cdev != NULL ? cdev->si_drv1 : NULL);
2481 }
2482 
2483 int
2484 __register_chrdev(unsigned int major, unsigned int baseminor,
2485     unsigned int count, const char *name,
2486     const struct file_operations *fops)
2487 {
2488 	struct linux_cdev *cdev;
2489 	int ret = 0;
2490 	int i;
2491 
2492 	for (i = baseminor; i < baseminor + count; i++) {
2493 		cdev = cdev_alloc();
2494 		cdev->ops = fops;
2495 		kobject_set_name(&cdev->kobj, name);
2496 
2497 		ret = cdev_add(cdev, makedev(major, i), 1);
2498 		if (ret != 0)
2499 			break;
2500 	}
2501 	return (ret);
2502 }
2503 
2504 int
2505 __register_chrdev_p(unsigned int major, unsigned int baseminor,
2506     unsigned int count, const char *name,
2507     const struct file_operations *fops, uid_t uid,
2508     gid_t gid, int mode)
2509 {
2510 	struct linux_cdev *cdev;
2511 	int ret = 0;
2512 	int i;
2513 
2514 	for (i = baseminor; i < baseminor + count; i++) {
2515 		cdev = cdev_alloc();
2516 		cdev->ops = fops;
2517 		kobject_set_name(&cdev->kobj, name);
2518 
2519 		ret = cdev_add_ext(cdev, makedev(major, i), uid, gid, mode);
2520 		if (ret != 0)
2521 			break;
2522 	}
2523 	return (ret);
2524 }
2525 
2526 void
2527 __unregister_chrdev(unsigned int major, unsigned int baseminor,
2528     unsigned int count, const char *name)
2529 {
2530 	struct linux_cdev *cdevp;
2531 	int i;
2532 
2533 	for (i = baseminor; i < baseminor + count; i++) {
2534 		cdevp = linux_find_cdev(name, major, i);
2535 		if (cdevp != NULL)
2536 			cdev_del(cdevp);
2537 	}
2538 }
2539 
2540 void
2541 linux_dump_stack(void)
2542 {
2543 #ifdef STACK
2544 	struct stack st;
2545 
2546 	stack_save(&st);
2547 	stack_print(&st);
2548 #endif
2549 }
2550 
2551 int
2552 linuxkpi_net_ratelimit(void)
2553 {
2554 
2555 	return (ppsratecheck(&lkpi_net_lastlog, &lkpi_net_curpps,
2556 	   lkpi_net_maxpps));
2557 }
2558 
2559 struct io_mapping *
2560 io_mapping_create_wc(resource_size_t base, unsigned long size)
2561 {
2562 	struct io_mapping *mapping;
2563 
2564 	mapping = kmalloc(sizeof(*mapping), GFP_KERNEL);
2565 	if (mapping == NULL)
2566 		return (NULL);
2567 	return (io_mapping_init_wc(mapping, base, size));
2568 }
2569 
2570 #if defined(__i386__) || defined(__amd64__)
2571 bool linux_cpu_has_clflush;
2572 struct cpuinfo_x86 boot_cpu_data;
2573 struct cpuinfo_x86 *__cpu_data;
2574 #endif
2575 
2576 cpumask_t *
2577 lkpi_get_static_single_cpu_mask(int cpuid)
2578 {
2579 
2580 	KASSERT((cpuid >= 0 && cpuid <= mp_maxid), ("%s: invalid cpuid %d\n",
2581 	    __func__, cpuid));
2582 	KASSERT(!CPU_ABSENT(cpuid), ("%s: cpu with cpuid %d is absent\n",
2583 	    __func__, cpuid));
2584 
2585 	return (static_single_cpu_mask[cpuid]);
2586 }
2587 
2588 static void
2589 linux_compat_init(void *arg)
2590 {
2591 	struct sysctl_oid *rootoid;
2592 	int i;
2593 
2594 #if defined(__i386__) || defined(__amd64__)
2595 	linux_cpu_has_clflush = (cpu_feature & CPUID_CLFSH);
2596 	boot_cpu_data.x86_clflush_size = cpu_clflush_line_size;
2597 	boot_cpu_data.x86_max_cores = mp_ncpus;
2598 	boot_cpu_data.x86 = CPUID_TO_FAMILY(cpu_id);
2599 	boot_cpu_data.x86_model = CPUID_TO_MODEL(cpu_id);
2600 
2601 	__cpu_data = mallocarray(mp_maxid + 1,
2602 	    sizeof(*__cpu_data), M_KMALLOC, M_WAITOK | M_ZERO);
2603 	CPU_FOREACH(i) {
2604 		__cpu_data[i].x86_clflush_size = cpu_clflush_line_size;
2605 		__cpu_data[i].x86_max_cores = mp_ncpus;
2606 		__cpu_data[i].x86 = CPUID_TO_FAMILY(cpu_id);
2607 		__cpu_data[i].x86_model = CPUID_TO_MODEL(cpu_id);
2608 	}
2609 #endif
2610 	rw_init(&linux_vma_lock, "lkpi-vma-lock");
2611 
2612 	rootoid = SYSCTL_ADD_ROOT_NODE(NULL,
2613 	    OID_AUTO, "sys", CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, "sys");
2614 	kobject_init(&linux_class_root, &linux_class_ktype);
2615 	kobject_set_name(&linux_class_root, "class");
2616 	linux_class_root.oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(rootoid),
2617 	    OID_AUTO, "class", CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, "class");
2618 	kobject_init(&linux_root_device.kobj, &linux_dev_ktype);
2619 	kobject_set_name(&linux_root_device.kobj, "device");
2620 	linux_root_device.kobj.oidp = SYSCTL_ADD_NODE(NULL,
2621 	    SYSCTL_CHILDREN(rootoid), OID_AUTO, "device",
2622 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "device");
2623 	linux_root_device.bsddev = root_bus;
2624 	linux_class_misc.name = "misc";
2625 	class_register(&linux_class_misc);
2626 	INIT_LIST_HEAD(&pci_drivers);
2627 	INIT_LIST_HEAD(&pci_devices);
2628 	spin_lock_init(&pci_lock);
2629 	mtx_init(&vmmaplock, "IO Map lock", NULL, MTX_DEF);
2630 	for (i = 0; i < VMMAP_HASH_SIZE; i++)
2631 		LIST_INIT(&vmmaphead[i]);
2632 	init_waitqueue_head(&linux_bit_waitq);
2633 	init_waitqueue_head(&linux_var_waitq);
2634 
2635 	CPU_COPY(&all_cpus, &cpu_online_mask);
2636 	/*
2637 	 * Generate a single-CPU cpumask_t for each CPU (possibly) in the system.
2638 	 * CPUs are indexed from 0..(mp_maxid).  The entry for cpuid 0 will only
2639 	 * have itself in the cpumask, cupid 1 only itself on entry 1, and so on.
2640 	 * This is used by cpumask_of() (and possibly others in the future) for,
2641 	 * e.g., drivers to pass hints to irq_set_affinity_hint().
2642 	 */
2643 	static_single_cpu_mask = mallocarray(mp_maxid + 1,
2644 	    sizeof(static_single_cpu_mask), M_KMALLOC, M_WAITOK | M_ZERO);
2645 
2646 	/*
2647 	 * When the number of CPUs reach a threshold, we start to save memory
2648 	 * given the sets are static by overlapping those having their single
2649 	 * bit set at same position in a bitset word.  Asymptotically, this
2650 	 * regular scheme is in O(n²) whereas the overlapping one is in O(n)
2651 	 * only with n being the maximum number of CPUs, so the gain will become
2652 	 * huge quite quickly.  The threshold for 64-bit architectures is 128
2653 	 * CPUs.
2654 	 */
2655 	if (mp_ncpus < (2 * _BITSET_BITS)) {
2656 		cpumask_t *sscm_ptr;
2657 
2658 		/*
2659 		 * This represents 'mp_ncpus * __bitset_words(CPU_SETSIZE) *
2660 		 * (_BITSET_BITS / 8)' bytes (for comparison with the
2661 		 * overlapping scheme).
2662 		 */
2663 		static_single_cpu_mask_lcs = mallocarray(mp_ncpus,
2664 		    sizeof(*static_single_cpu_mask_lcs),
2665 		    M_KMALLOC, M_WAITOK | M_ZERO);
2666 
2667 		sscm_ptr = static_single_cpu_mask_lcs;
2668 		CPU_FOREACH(i) {
2669 			static_single_cpu_mask[i] = sscm_ptr++;
2670 			CPU_SET(i, static_single_cpu_mask[i]);
2671 		}
2672 	} else {
2673 		/* Pointer to a bitset word. */
2674 		__typeof(((cpuset_t *)NULL)->__bits[0]) *bwp;
2675 
2676 		/*
2677 		 * Allocate memory for (static) spans of 'cpumask_t' ('cpuset_t'
2678 		 * really) with a single bit set that can be reused for all
2679 		 * single CPU masks by making them start at different offsets.
2680 		 * We need '__bitset_words(CPU_SETSIZE) - 1' bitset words before
2681 		 * the word having its single bit set, and the same amount
2682 		 * after.
2683 		 */
2684 		static_single_cpu_mask_lcs = mallocarray(_BITSET_BITS,
2685 		    (2 * __bitset_words(CPU_SETSIZE) - 1) * (_BITSET_BITS / 8),
2686 		    M_KMALLOC, M_WAITOK | M_ZERO);
2687 
2688 		/*
2689 		 * We rely below on cpuset_t and the bitset generic
2690 		 * implementation assigning words in the '__bits' array in the
2691 		 * same order of bits (i.e., little-endian ordering, not to be
2692 		 * confused with machine endianness, which concerns bits in
2693 		 * words and other integers).  This is an imperfect test, but it
2694 		 * will detect a change to big-endian ordering.
2695 		 */
2696 		_Static_assert(
2697 		    __bitset_word(_BITSET_BITS + 1, _BITSET_BITS) == 1,
2698 		    "Assumes a bitset implementation that is little-endian "
2699 		    "on its words");
2700 
2701 		/* Initialize the single bit of each static span. */
2702 		bwp = (__typeof(bwp))static_single_cpu_mask_lcs +
2703 		    (__bitset_words(CPU_SETSIZE) - 1);
2704 		for (i = 0; i < _BITSET_BITS; i++) {
2705 			CPU_SET(i, (cpuset_t *)bwp);
2706 			bwp += (2 * __bitset_words(CPU_SETSIZE) - 1);
2707 		}
2708 
2709 		/*
2710 		 * Finally set all CPU masks to the proper word in their
2711 		 * relevant span.
2712 		 */
2713 		CPU_FOREACH(i) {
2714 			bwp = (__typeof(bwp))static_single_cpu_mask_lcs;
2715 			/* Find the non-zero word of the relevant span. */
2716 			bwp += (2 * __bitset_words(CPU_SETSIZE) - 1) *
2717 			    (i % _BITSET_BITS) +
2718 			    __bitset_words(CPU_SETSIZE) - 1;
2719 			/* Shift to find the CPU mask start. */
2720 			bwp -= (i / _BITSET_BITS);
2721 			static_single_cpu_mask[i] = (cpuset_t *)bwp;
2722 		}
2723 	}
2724 
2725 	strlcpy(init_uts_ns.name.release, osrelease, sizeof(init_uts_ns.name.release));
2726 }
2727 SYSINIT(linux_compat, SI_SUB_DRIVERS, SI_ORDER_SECOND, linux_compat_init, NULL);
2728 
2729 static void
2730 linux_compat_uninit(void *arg)
2731 {
2732 	linux_kobject_kfree_name(&linux_class_root);
2733 	linux_kobject_kfree_name(&linux_root_device.kobj);
2734 	linux_kobject_kfree_name(&linux_class_misc.kobj);
2735 
2736 	free(static_single_cpu_mask_lcs, M_KMALLOC);
2737 	free(static_single_cpu_mask, M_KMALLOC);
2738 #if defined(__i386__) || defined(__amd64__)
2739 	free(__cpu_data, M_KMALLOC);
2740 #endif
2741 
2742 	mtx_destroy(&vmmaplock);
2743 	spin_lock_destroy(&pci_lock);
2744 	rw_destroy(&linux_vma_lock);
2745 }
2746 SYSUNINIT(linux_compat, SI_SUB_DRIVERS, SI_ORDER_SECOND, linux_compat_uninit, NULL);
2747 
2748 /*
2749  * NOTE: Linux frequently uses "unsigned long" for pointer to integer
2750  * conversion and vice versa, where in FreeBSD "uintptr_t" would be
2751  * used. Assert these types have the same size, else some parts of the
2752  * LinuxKPI may not work like expected:
2753  */
2754 CTASSERT(sizeof(unsigned long) == sizeof(uintptr_t));
2755