Index: sys/compat/linuxkpi/common/include/asm/atomic.h
===================================================================
--- sys/compat/linuxkpi/common/include/asm/atomic.h
+++ sys/compat/linuxkpi/common/include/asm/atomic.h
@@ -159,6 +159,23 @@
 	return (ret);
 }
 
+static inline int
+atomic_dec_if_positive(atomic_t *v) {
+	int c, old, dec;
+
+	c = atomic_read(v);
+	for (;;) {
+		dec = c - 1;
+		if (unlikely(dec < 0))
+			break;
+		old = atomic_cmpxchg((v), c, dec);
+		if (likely(old == c))
+			break;
+		c = old;
+	}
+	return dec;
+}
+
 #define	cmpxchg(ptr, old, new) ({					\
 	union {								\
 		__typeof(*(ptr)) val;					\
Index: sys/compat/linuxkpi/common/include/asm/msr.h
===================================================================
--- sys/compat/linuxkpi/common/include/asm/msr.h
+++ sys/compat/linuxkpi/common/include/asm/msr.h
@@ -32,5 +32,6 @@
 #include <machine/cpufunc.h>
 
 #define	rdmsrl(msr, val)	((val) = rdmsr(msr))
+#define	rdmsrl_safe(msr, val)	rdmsr_safe((msr), (val))
 
 #endif /* _ASM_MSR_H_ */
Index: sys/compat/linuxkpi/common/include/asm/uaccess.h
===================================================================
--- sys/compat/linuxkpi/common/include/asm/uaccess.h
+++ sys/compat/linuxkpi/common/include/asm/uaccess.h
@@ -31,25 +31,32 @@
 #ifndef _ASM_UACCESS_H_
 #define _ASM_UACCESS_H_
 
-#include <linux/uaccess.h>
+/*
 
-static inline long
-copy_to_user(void *to, const void *from, unsigned long n)
-{
-	if (linux_copyout(from, to, n) != 0)
-		return n;
-	return 0;
-}
-#define	__copy_to_user(...)	copy_to_user(__VA_ARGS__)
+Disable. Need __{get,put}_user_size() functions...
+Use defaults in linux/uaccess.h for now.
 
-static inline long
-copy_from_user(void *to, const void *from, unsigned long n)
-{
-	if (linux_copyin(from, to, n) != 0)
-		return n;
-	return 0;
-}
-#define	__copy_from_user(...)	copy_from_user(__VA_ARGS__)
-#define	__copy_in_user(...)	copy_from_user(__VA_ARGS__)
+#define	user_access_begin() stac()
+#define	user_access_end()   clac()
+
+#define	unsafe_put_user(x, ptr, err_label)				\
+	do {								\
+		int __error;						\
+		__typeof__(*(ptr)) __x = (x);				\
+		__put_user_size(__x, (ptr), sizeof(*(ptr)),		\
+		    __error, -EFAULT);					\
+		if (unlikely(__error)) goto err_label;			\
+	} while (0)
+
+#define	unsafe_get_user(x, ptr, err_label)				\
+	do {								\
+		int __error;						\
+		__inttype(*(ptr)) __x;					\
+		__get_user_size(__x, (ptr), sizeof(*(ptr)),		\
+		    __error, -EFAULT);					\
+		(x) = (__force __typeof__(*(ptr)))__x;			\
+		if (unlikely(__error)) goto err_label;			\
+	} while (0)
+*/
 
 #endif	/* _ASM_UACCESS_H_ */
Index: sys/compat/linuxkpi/common/include/linux/compiler.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/compiler.h
+++ sys/compat/linuxkpi/common/include/linux/compiler.h
@@ -34,6 +34,10 @@
 
 #include <sys/cdefs.h>
 
+#ifndef __LinuxKPI_version
+#define	__LinuxKPI_version 40009
+#endif
+
 #define __user
 #define __kernel
 #define __safe
Index: sys/compat/linuxkpi/common/include/linux/device.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/device.h
+++ sys/compat/linuxkpi/common/include/linux/device.h
@@ -461,6 +461,12 @@
 		device_unregister(device_get_softc(bsddev));
 }
 
+static inline void
+dev_pm_set_driver_flags(struct device *dev, u32 flags)
+{
+	printf("%s: missing implementation\n", __func__);
+}
+
 static inline void
 linux_class_kfree(struct class *class)
 {
Index: sys/compat/linuxkpi/common/include/linux/export.h
===================================================================
--- /dev/null
+++ sys/compat/linuxkpi/common/include/linux/export.h
@@ -0,0 +1,8 @@
+#ifndef _LINUX_EXPORT_H
+#define _LINUX_EXPORT_H
+
+#define	NR_IRQS 512	/* XXX Need correct value */
+#define	EXPORT_SYMBOL(name)
+#define	EXPORT_SYMBOL_GPL(name)
+
+#endif
Index: sys/compat/linuxkpi/common/include/linux/kernel.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/kernel.h
+++ sys/compat/linuxkpi/common/include/linux/kernel.h
@@ -88,7 +88,9 @@
 
 #define	BUILD_BUG()			do { CTASSERT(0); } while (0)
 #define	BUILD_BUG_ON(x)			CTASSERT(!(x))
+#ifndef BUILD_BUG_ON_MSG
 #define	BUILD_BUG_ON_MSG(x, msg)	BUILD_BUG_ON(x)
+#endif
 #define	BUILD_BUG_ON_NOT_POWER_OF_2(x)	BUILD_BUG_ON(!powerof2(x))
 #define	BUILD_BUG_ON_INVALID(expr)	while (0) { (void)(expr); }
 
@@ -372,6 +374,56 @@
 	return (0);
 }
 
+static inline int
+kstrtobool(const char *s, bool *res)
+{
+	if (!s)
+		return -EINVAL;
+
+	switch (s[0]) {
+	case 'y':
+	case 'Y':
+	case '1':
+		*res = true;
+		return 0;
+	case 'n':
+	case 'N':
+	case '0':
+		*res = false;
+		return 0;
+	case 'o':
+	case 'O':
+		switch (s[1]) {
+		case 'n':
+		case 'N':
+			*res = true;
+			return 0;
+		case 'f':
+		case 'F':
+			*res = false;
+			return 0;
+		default:
+			break;
+		}
+	default:
+		break;
+	}
+
+	return -EINVAL;
+}
+
+static inline int
+kstrtobool_from_user(const char __user *s, size_t count, bool *res)
+{
+	char buf[4];
+
+	count = min(count, sizeof(buf) - 1);
+	if (copy_from_user(buf, s, count))
+		return -EFAULT;
+	buf[count] = '\0';
+	return kstrtobool(buf, res);
+}
+
 #define min(x, y)	((x) < (y) ? (x) : (y))
 #define max(x, y)	((x) > (y) ? (x) : (y))
 
Index: sys/compat/linuxkpi/common/include/linux/ktime.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/ktime.h
+++ sys/compat/linuxkpi/common/include/linux/ktime.h
@@ -127,6 +127,22 @@
 	return (lhs + rhs);
 }
 
+static inline int
+ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
+{
+	if (cmp1 < cmp2)
+		return -1;
+	if (cmp1 > cmp2)
+		return 1;
+	return 0;
+}
+
+static inline bool
+ktime_after(const ktime_t cmp1, const ktime_t cmp2)
+{
+	return ktime_compare(cmp1, cmp2) > 0;
+}
+
 static inline ktime_t
 timespec_to_ktime(struct timespec ts)
 {
@@ -140,6 +156,7 @@
 }
 
 #define	ktime_to_timespec(kt)		ns_to_timespec(kt)
+#define	ktime_to_timespec64(kt)		ns_to_timespec(kt)
 #define	ktime_to_timeval(kt)		ns_to_timeval(kt)
 #define	ktime_to_ns(kt)			(kt)
 
Index: sys/compat/linuxkpi/common/include/linux/list.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/list.h
+++ sys/compat/linuxkpi/common/include/linux/list.h
@@ -337,16 +337,23 @@
 hlist_empty(const struct hlist_head *h)
 {
 
-	return !h->first;
+	return !READ_ONCE(h->first);
+}
+
+static inline void
+__hlist_del(struct hlist_node *n)
+{
+
+	WRITE_ONCE(*(n->pprev), n->next);
+        if (n->next)
+                n->next->pprev = n->pprev;
 }
 
 static inline void
 hlist_del(struct hlist_node *n)
 {
 
-	if (n->next)
-		n->next->pprev = n->pprev;
-	*n->pprev = n->next;
+	__hlist_del(n);
 }
 
 static inline void
@@ -366,7 +373,7 @@
 	n->next = h->first;
 	if (h->first)
 		h->first->pprev = &n->next;
-	h->first = n;
+	WRITE_ONCE(h->first, n);
 	n->pprev = &h->first;
 }
 
@@ -377,18 +384,19 @@
 	n->pprev = next->pprev;
 	n->next = next;
 	next->pprev = &n->next;
-	*(n->pprev) = n;
+	WRITE_ONCE(*(n->pprev), n);
 }
 
 static inline void
-hlist_add_after(struct hlist_node *n, struct hlist_node *next)
+hlist_add_behind(struct hlist_node *n, struct hlist_node *prev)
 {
 
-	next->next = n->next;
-	n->next = next;
-	next->pprev = &n->next;
-	if (next->next)
-		next->next->pprev = &next->next;
+	n->next = prev->next;
+	WRITE_ONCE(prev->next, n);
+	n->pprev = &prev->next;
+
+	if (n->next)
+		n->next->pprev  = &n->next;
 }
 
 static inline void
Index: sys/compat/linuxkpi/common/include/linux/mmu_context.h
===================================================================
--- /dev/null
+++ sys/compat/linuxkpi/common/include/linux/mmu_context.h
@@ -0,0 +1,20 @@
+#ifndef _LINUX_MMU_CONTEXT_H
+#define _LINUX_MMU_CONTEXT_H
+
+struct mm_struct;
+
+static inline void
+use_mm(struct mm_struct *mm)
+{
+
+	printf("%s: missing implementation!\n", __func__);
+}
+
+static inline void
+unuse_mm(struct mm_struct *mm)
+{
+
+	printf("%s: missing implementation!\n", __func__);
+}
+
+#endif
Index: sys/compat/linuxkpi/common/include/linux/module.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/module.h
+++ sys/compat/linuxkpi/common/include/linux/module.h
@@ -42,6 +42,7 @@
 #include <linux/sysfs.h>
 #include <linux/moduleparam.h>
 #include <linux/slab.h>
+#include <linux/export.h>
 
 #define MODULE_AUTHOR(name)
 #define MODULE_DESCRIPTION(name)
@@ -51,8 +52,6 @@
 
 #define	THIS_MODULE	((struct module *)0)
 
-#define	EXPORT_SYMBOL(name)
-#define	EXPORT_SYMBOL_GPL(name)
 #define	__MODULE_STRING(x) __stringify(x)
 
 /* OFED pre-module initialization */
Index: sys/compat/linuxkpi/common/include/linux/slab.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/slab.h
+++ sys/compat/linuxkpi/common/include/linux/slab.h
@@ -85,6 +85,8 @@
 #define	SLAB_DESTROY_BY_RCU \
 	SLAB_TYPESAFE_BY_RCU
 
+#define	ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
+
 static inline gfp_t
 linux_check_m_flags(gfp_t flags)
 {
Index: sys/compat/linuxkpi/common/include/linux/time.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/time.h
+++ sys/compat/linuxkpi/common/include/linux/time.h
@@ -38,6 +38,8 @@
 #include <sys/time.h>
 #include <sys/stdint.h>
 
+#define	timespec64	timespec
+
 static inline struct timeval
 ns_to_timeval(const int64_t nsec)
 {
Index: sys/compat/linuxkpi/common/include/linux/timer.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/timer.h
+++ sys/compat/linuxkpi/common/include/linux/timer.h
@@ -64,7 +64,7 @@
 #define	setup_timer(timer, func, dat) do {				\
 	(timer)->function = (func);					\
 	(timer)->data = (dat);						\
-	callout_init(&(timer)->callout, 1);			\
+	callout_init(&(timer)->callout, 1);				\
 } while (0)
 
 #define	__setup_timer(timer, func, dat, flags) do {			\
@@ -75,7 +75,7 @@
 #define	init_timer(timer) do {						\
 	(timer)->function = NULL;					\
 	(timer)->data = 0;						\
-	callout_init(&(timer)->callout, 1);			\
+	callout_init(&(timer)->callout, 1);				\
 } while (0)
 
 extern void mod_timer(struct timer_list *, int);
Index: sys/compat/linuxkpi/common/include/linux/uaccess.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/uaccess.h
+++ sys/compat/linuxkpi/common/include/linux/uaccess.h
@@ -42,6 +42,8 @@
 
 #include <linux/compiler.h>
 
+#include <asm/uaccess.h>
+
 #define	VERIFY_READ	VM_PROT_READ
 #define	VERIFY_WRITE	VM_PROT_WRITE
 
@@ -67,6 +69,25 @@
 extern size_t linux_clear_user(void *uaddr, size_t len);
 extern int linux_access_ok(int rw, const void *uaddr, size_t len);
 
+static inline long
+copy_to_user(void *to, const void *from, unsigned long n)
+{
+	if (linux_copyout(from, to, n) != 0)
+		return n;
+	return 0;
+}
+#define	__copy_to_user(...)	copy_to_user(__VA_ARGS__)
+
+static inline long
+copy_from_user(void *to, const void *from, unsigned long n)
+{
+	if (linux_copyin(from, to, n) != 0)
+		return n;
+	return 0;
+}
+#define	__copy_from_user(...)	copy_from_user(__VA_ARGS__)
+#define	__copy_in_user(...)	copy_from_user(__VA_ARGS__)
+
 /*
  * NOTE: Each pagefault_disable() call must have a corresponding
  * pagefault_enable() call in the same scope. The former creates a new
@@ -88,4 +109,20 @@
 	return ((curthread->td_pflags & TDP_NOFAULTING) != 0);
 }
 
+#ifndef	user_access_begin
+#define	user_access_begin() do { } while (0)
+#define	user_access_end() do { } while (0)
+
+#define	unsafe_get_user(x, ptr, err) do {		\
+		if (unlikely(__get_user(x, ptr)))	\
+			goto err;			\
+	} while (0)
+
+#define	unsafe_put_user(x, ptr, err) do {		\
+		if (unlikely(__put_user(x, ptr)))	\
+			goto err;			\
+	} while (0)
+
+#endif
+
 #endif					/* _LINUX_UACCESS_H_ */
Index: sys/compat/linuxkpi/common/include/linux/wait.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/wait.h
+++ sys/compat/linuxkpi/common/include/linux/wait.h
@@ -47,12 +47,19 @@
 #define	might_sleep()							\
 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "might_sleep()")
 
+#define	might_sleep_if(cond) do { if (cond) might_sleep(); } while (0)
+
+#if __LinuxKPI_version >= 40013
+#define	__add_wait_queue_entry_tail(wqh,wq) __add_wait_queue_tail((wqh),(wq))
+#define	wait_queue_entry wait_queue
+#define	wait_queue_entry_t wait_queue_t
+#endif
+
 struct wait_queue;
 struct wait_queue_head;
 
 typedef struct wait_queue wait_queue_t;
 typedef struct wait_queue_head wait_queue_head_t;
-
 typedef int wait_queue_func_t(wait_queue_t *, unsigned int, int, void *);
 
 /*
@@ -63,12 +70,23 @@
 	unsigned int flags;	/* always 0 */
 	void *private;
 	wait_queue_func_t *func;
-	struct list_head task_list;
+	union {
+		/*
+		 * Changes in Linux v4.13.
+		 * Remove deprecated code when we
+		 * don't depend on < 4.13 any more.
+		 */
+		struct list_head task_list; /* < v.4.13 */
+		struct list_head entry; /* >= v4.13 */
+	};
 };
 
 struct wait_queue_head {
 	spinlock_t lock;
-	struct list_head task_list;
+	union {
+		struct list_head task_list; /* < v.4.13 */
+		struct list_head head; /* >= v4.13 */
+	};
 };
 
 /*
@@ -106,8 +124,12 @@
 	INIT_LIST_HEAD(&(wqh)->task_list);				\
 } while (0)
 
+void linux_init_wait_entry(wait_queue_t *wait, int flags);
 void linux_wake_up(wait_queue_head_t *, unsigned int, int, bool);
 
+#define	init_wait_entry(w, f)						\
+	linux_init_wait_entry(w, f)
+
 #define	wake_up(wqh)							\
 	linux_wake_up(wqh, TASK_NORMAL, 1, false)
 #define	wake_up_all(wqh)						\
Index: sys/compat/linuxkpi/common/include/linux/ww_mutex.h
===================================================================
--- sys/compat/linuxkpi/common/include/linux/ww_mutex.h
+++ sys/compat/linuxkpi/common/include/linux/ww_mutex.h
@@ -35,6 +35,8 @@
 
 #include <linux/mutex.h>
 
+struct task_struct;
+
 struct ww_class {
 	const char *mutex_name;
 };
@@ -44,6 +46,7 @@
 
 struct ww_mutex {
 	struct mutex base;
+	struct ww_acquire_ctx *ctx;
 	struct cv condvar;
 };
 
@@ -111,32 +114,35 @@
 }
 
 static inline void
-ww_mutex_destroy(struct ww_mutex *lock)
+ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class)
 {
-	cv_destroy(&lock->condvar);
-	mutex_destroy(&lock->base);
+	linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS);
+	cv_init(&lock->condvar, "lkpi-ww");
 }
 
 static inline void
-ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class)
+ww_mutex_destroy(struct ww_mutex *lock)
 {
+	cv_destroy(&lock->condvar);
+	mutex_destroy(&lock->base);
 }
 
 static inline void
-ww_mutex_init(struct ww_mutex *lock, struct ww_class *ww_class)
+ww_acquire_init(struct ww_acquire_ctx *ctx, struct ww_class *ww_class)
 {
-	linux_mutex_init(&lock->base, ww_class->mutex_name, SX_NOWITNESS);
-	cv_init(&lock->condvar, "lkpi-ww");
+	// NOP is deliberate
 }
 
 static inline void
 ww_acquire_fini(struct ww_acquire_ctx *ctx)
 {
+	// NOP is deliberate
 }
 
 static inline void
 ww_acquire_done(struct ww_acquire_ctx *ctx)
 {
+	// NOP is deliberate
 }
 
 #endif					/* _LINUX_WW_MUTEX_H_ */
Index: sys/compat/linuxkpi/common/src/linux_schedule.c
===================================================================
--- sys/compat/linuxkpi/common/src/linux_schedule.c
+++ sys/compat/linuxkpi/common/src/linux_schedule.c
@@ -187,6 +187,15 @@
 	return (wake_up_task(wq->private, state));
 }
 
+void
+linux_init_wait_entry(wait_queue_t *wait, int flags)
+{
+	wait->flags = flags;
+	wait->private = current;
+	wait->func = autoremove_wake_function;
+	INIT_LIST_HEAD(&wait->task_list);
+}
+
 void
 linux_wake_up(wait_queue_head_t *wqh, unsigned int state, int nr, bool locked)
 {