diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h
index bd15bf9164c23264e7c6040e9a2a4d4fe3a69451..f9bc6acd36798cc3077861deb95fa4f3089f0125 100644
--- a/include/linux/highmem-internal.h
+++ b/include/linux/highmem-internal.h
@@ -90,7 +90,10 @@ static inline void __kunmap_local(void *vaddr)
 
 static inline void *kmap_atomic(struct page *page)
 {
-	preempt_disable();
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		migrate_disable();
+	else
+		preempt_disable();
 	pagefault_disable();
 	return __kmap_local_page_prot(page, kmap_prot);
 }
@@ -99,7 +102,10 @@ static inline void __kunmap_atomic(void *addr)
 {
 	kunmap_local_indexed(addr);
 	pagefault_enable();
-	preempt_enable();
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		migrate_enable();
+	else
+		preempt_enable();
 }
 
 unsigned int __nr_free_highpages(void);
@@ -172,7 +178,10 @@ static inline void __kunmap_local(void *addr)
 
 static inline void *kmap_atomic(struct page *page)
 {
-	preempt_disable();
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		migrate_disable();
+	else
+		preempt_disable();
 	pagefault_disable();
 	return page_address(page);
 }
@@ -183,7 +192,10 @@ static inline void __kunmap_atomic(void *addr)
 	kunmap_flush_on_unmap(addr);
 #endif
 	pagefault_enable();
-	preempt_enable();
+	if (IS_ENABLED(CONFIG_PREEMPT_RT))
+		migrate_enable();
+	else
+		preempt_enable();
 }
 
 static inline unsigned int nr_free_highpages(void) { return 0; }
diff --git a/lib/test_lockup.c b/lib/test_lockup.c
index 78a630bbd03dfac16a45141953cba13c6a1a7e39..d27a80502204be3eecd20fb79e7c0bdddadc9f85 100644
--- a/lib/test_lockup.c
+++ b/lib/test_lockup.c
@@ -485,6 +485,21 @@ static int __init test_lockup_init(void)
 		return -EINVAL;
 
 #ifdef CONFIG_DEBUG_SPINLOCK
+#ifdef CONFIG_PREEMPT_RT
+	if (test_magic(lock_spinlock_ptr,
+		       offsetof(spinlock_t, lock.wait_lock.magic),
+		       SPINLOCK_MAGIC) ||
+	    test_magic(lock_rwlock_ptr,
+		       offsetof(rwlock_t, rtmutex.wait_lock.magic),
+		       SPINLOCK_MAGIC) ||
+	    test_magic(lock_mutex_ptr,
+		       offsetof(struct mutex, lock.wait_lock.magic),
+		       SPINLOCK_MAGIC) ||
+	    test_magic(lock_rwsem_ptr,
+		       offsetof(struct rw_semaphore, rtmutex.wait_lock.magic),
+		       SPINLOCK_MAGIC))
+		return -EINVAL;
+#else
 	if (test_magic(lock_spinlock_ptr,
 		       offsetof(spinlock_t, rlock.magic),
 		       SPINLOCK_MAGIC) ||
@@ -498,6 +513,7 @@ static int __init test_lockup_init(void)
 		       offsetof(struct rw_semaphore, wait_lock.magic),
 		       SPINLOCK_MAGIC))
 		return -EINVAL;
+#endif
 #endif
 
 	if ((wait_state != TASK_RUNNING ||
diff --git a/mm/highmem.c b/mm/highmem.c
index 8db577e5290cc87f1e2e37e05c37aa7078fac445..72b9a2d95c72ae1fe1e9758e2700a0d6bedc0d5b 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -422,12 +422,15 @@ static inline void *arch_kmap_local_high_get(struct page *page)
 #endif
 
 /* Unmap a local mapping which was obtained by kmap_high_get() */
-static inline void kmap_high_unmap_local(unsigned long vaddr)
+static inline bool kmap_high_unmap_local(unsigned long vaddr)
 {
 #ifdef ARCH_NEEDS_KMAP_HIGH_GET
-	if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP))
+	if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
 		kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
+		return true;
+	}
 #endif
+	return false;
 }
 
 static inline int kmap_local_calc_idx(int idx)
@@ -493,10 +496,14 @@ void kunmap_local_indexed(void *vaddr)
 
 	if (addr < __fix_to_virt(FIX_KMAP_END) ||
 	    addr > __fix_to_virt(FIX_KMAP_BEGIN)) {
-		WARN_ON_ONCE(addr < PAGE_OFFSET);
-
-		/* Handle mappings which were obtained by kmap_high_get() */
-		kmap_high_unmap_local(addr);
+		/*
+		 * Handle mappings which were obtained by kmap_high_get()
+		 * first as the virtual address of such mappings is below
+		 * PAGE_OFFSET. Warn for all other addresses which are in
+		 * the user space part of the virtual address space.
+		 */
+		if (!kmap_high_unmap_local(addr))
+			WARN_ON_ONCE(addr < PAGE_OFFSET);
 		return;
 	}