3 files changed, 101 insertions, 173 deletions
diff --git a/include/linux/local_lock.h b/include/linux/local_lock.h
index 1a0bc35839e3..16a2ee4f8310 100644
--- a/include/linux/local_lock.h
+++ b/include/linux/local_lock.h
@@ -52,44 +52,23 @@
 	__local_unlock_irqrestore(lock, flags)
 
 /**
- * localtry_lock_init - Runtime initialize a lock instance
- */
-#define localtry_lock_init(lock)		__localtry_lock_init(lock)
-
-/**
- * localtry_lock - Acquire a per CPU local lock
- * @lock:	The lock variable
- */
-#define localtry_lock(lock)		__localtry_lock(lock)
-
-/**
- * localtry_lock_irq - Acquire a per CPU local lock and disable interrupts
- * @lock:	The lock variable
- */
-#define localtry_lock_irq(lock)		__localtry_lock_irq(lock)
-
-/**
- * localtry_lock_irqsave - Acquire a per CPU local lock, save and disable
- *			 interrupts
- * @lock:	The lock variable
- * @flags:	Storage for interrupt flags
+ * local_lock_init - Runtime initialize a lock instance
  */
-#define localtry_lock_irqsave(lock, flags)				\
-	__localtry_lock_irqsave(lock, flags)
+#define local_trylock_init(lock)	__local_trylock_init(lock)
 
 /**
- * localtry_trylock - Try to acquire a per CPU local lock.
+ * local_trylock - Try to acquire a per CPU local lock
  * @lock:	The lock variable
  *
  * The function can be used in any context such as NMI or HARDIRQ. Due to
  * locking constrains it will _always_ fail to acquire the lock in NMI or
  * HARDIRQ context on PREEMPT_RT.
  */
-#define localtry_trylock(lock)		__localtry_trylock(lock)
+#define local_trylock(lock)		__local_trylock(lock)
 
 /**
- * localtry_trylock_irqsave - Try to acquire a per CPU local lock, save and disable
- *			      interrupts if acquired
+ * local_trylock_irqsave - Try to acquire a per CPU local lock, save and disable
+ *			   interrupts if acquired
  * @lock:	The lock variable
  * @flags:	Storage for interrupt flags
  *
@@ -97,29 +76,8 @@
  * locking constrains it will _always_ fail to acquire the lock in NMI or
  * HARDIRQ context on PREEMPT_RT.
  */
-#define localtry_trylock_irqsave(lock, flags)				\
-	__localtry_trylock_irqsave(lock, flags)
-
-/**
- * local_unlock - Release a per CPU local lock
- * @lock:	The lock variable
- */
-#define localtry_unlock(lock)		__localtry_unlock(lock)
-
-/**
- * local_unlock_irq - Release a per CPU local lock and enable interrupts
- * @lock:	The lock variable
- */
-#define localtry_unlock_irq(lock)		__localtry_unlock_irq(lock)
-
-/**
- * localtry_unlock_irqrestore - Release a per CPU local lock and restore
- *			      interrupt flags
- * @lock:	The lock variable
- * @flags:      Interrupt flags to restore
- */
-#define localtry_unlock_irqrestore(lock, flags)			\
-	__localtry_unlock_irqrestore(lock, flags)
+#define local_trylock_irqsave(lock, flags)			\
+	__local_trylock_irqsave(lock, flags)
 
 DEFINE_GUARD(local_lock, local_lock_t __percpu*,
 	     local_lock(_T),
diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h
index 67bd13d142fa..bf2bf40d7b18 100644
--- a/include/linux/local_lock_internal.h
+++ b/include/linux/local_lock_internal.h
@@ -15,10 +15,11 @@ typedef struct {
 #endif
 } local_lock_t;
 
+/* local_trylock() and local_trylock_irqsave() only work with local_trylock_t */
 typedef struct {
 	local_lock_t	llock;
-	unsigned int	acquired;
-} localtry_lock_t;
+	u8		acquired;
+} local_trylock_t;
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 # define LOCAL_LOCK_DEBUG_INIT(lockname)		\
@@ -29,6 +30,9 @@ typedef struct {
 	},						\
 	.owner = NULL,
 
+# define LOCAL_TRYLOCK_DEBUG_INIT(lockname)		\
+	.llock = { LOCAL_LOCK_DEBUG_INIT((lockname).llock) },
+
 static inline void local_lock_acquire(local_lock_t *l)
 {
 	lock_map_acquire(&l->dep_map);
@@ -56,6 +60,7 @@ static inline void local_lock_debug_init(local_lock_t *l)
 }
 #else /* CONFIG_DEBUG_LOCK_ALLOC */
 # define LOCAL_LOCK_DEBUG_INIT(lockname)
+# define LOCAL_TRYLOCK_DEBUG_INIT(lockname)
 static inline void local_lock_acquire(local_lock_t *l) { }
 static inline void local_trylock_acquire(local_lock_t *l) { }
 static inline void local_lock_release(local_lock_t *l) { }
@@ -63,7 +68,7 @@ static inline void local_lock_debug_init(local_lock_t *l) { }
 #endif /* !CONFIG_DEBUG_LOCK_ALLOC */
 
 #define INIT_LOCAL_LOCK(lockname)	{ LOCAL_LOCK_DEBUG_INIT(lockname) }
-#define INIT_LOCALTRY_LOCK(lockname)	{ .llock = { LOCAL_LOCK_DEBUG_INIT(lockname.llock) }}
+#define INIT_LOCAL_TRYLOCK(lockname)	{ LOCAL_TRYLOCK_DEBUG_INIT(lockname) }
 
 #define __local_lock_init(lock)					\
 do {								\
@@ -76,6 +81,8 @@ do {								\
 	local_lock_debug_init(lock);				\
 } while (0)
 
+#define __local_trylock_init(lock) __local_lock_init(lock.llock)
+
 #define __spinlock_nested_bh_init(lock)				\
 do {								\
 	static struct lock_class_key __key;			\
@@ -87,149 +94,117 @@ do {								\
 	local_lock_debug_init(lock);				\
 } while (0)
 
+#define __local_lock_acquire(lock)					\
+	do {								\
+		local_trylock_t *tl;					\
+		local_lock_t *l;					\
+									\
+		l = (local_lock_t *)this_cpu_ptr(lock);			\
+		tl = (local_trylock_t *)l;				\
+		_Generic((lock),					\
+			local_trylock_t *: ({				\
+				lockdep_assert(tl->acquired == 0);	\
+				WRITE_ONCE(tl->acquired, 1);		\
+			}),						\
+			default:(void)0);				\
+		local_lock_acquire(l);					\
+	} while (0)
+
 #define __local_lock(lock)					\
 	do {							\
 		preempt_disable();				\
-		local_lock_acquire(this_cpu_ptr(lock));		\
+		__local_lock_acquire(lock);			\
 	} while (0)
 
 #define __local_lock_irq(lock)					\
 	do {							\
 		local_irq_disable();				\
-		local_lock_acquire(this_cpu_ptr(lock));		\
+		__local_lock_acquire(lock);			\
 	} while (0)
 
 #define __local_lock_irqsave(lock, flags)			\
 	do {							\
 		local_irq_save(flags);				\
-		local_lock_acquire(this_cpu_ptr(lock));		\
-	} while (0)
-
-#define __local_unlock(lock)					\
-	do {							\
-		local_lock_release(this_cpu_ptr(lock));		\
-		preempt_enable();				\
+		__local_lock_acquire(lock);			\
 	} while (0)
 
-#define __local_unlock_irq(lock)				\
-	do {							\
-		local_lock_release(this_cpu_ptr(lock));		\
-		local_irq_enable();				\
-	} while (0)
-
-#define __local_unlock_irqrestore(lock, flags)			\
-	do {							\
-		local_lock_release(this_cpu_ptr(lock));		\
-		local_irq_restore(flags);			\
-	} while (0)
-
-#define __local_lock_nested_bh(lock)				\
-	do {							\
-		lockdep_assert_in_softirq();			\
-		local_lock_acquire(this_cpu_ptr(lock));	\
-	} while (0)
-
-#define __local_unlock_nested_bh(lock)				\
-	local_lock_release(this_cpu_ptr(lock))
-
-/* localtry_lock_t variants */
-
-#define __localtry_lock_init(lock)				\
-do {								\
-	__local_lock_init(&(lock)->llock);			\
-	WRITE_ONCE((lock)->acquired, 0);			\
-} while (0)
-
-#define __localtry_lock(lock)					\
-	do {							\
-		localtry_lock_t *lt;				\
-		preempt_disable();				\
-		lt = this_cpu_ptr(lock);			\
-		local_lock_acquire(&lt->llock);			\
-		WRITE_ONCE(lt->acquired, 1);			\
-	} while (0)
-
-#define __localtry_lock_irq(lock)				\
-	do {							\
-		localtry_lock_t *lt;				\
-		local_irq_disable();				\
-		lt = this_cpu_ptr(lock);			\
-		local_lock_acquire(&lt->llock);			\
-		WRITE_ONCE(lt->acquired, 1);			\
-	} while (0)
-
-#define __localtry_lock_irqsave(lock, flags)			\
-	do {							\
-		localtry_lock_t *lt;				\
-		local_irq_save(flags);				\
-		lt = this_cpu_ptr(lock);			\
-		local_lock_acquire(&lt->llock);			\
-		WRITE_ONCE(lt->acquired, 1);			\
-	} while (0)
-
-#define __localtry_trylock(lock)				\
+#define __local_trylock(lock)					\
 	({							\
-		localtry_lock_t *lt;				\
-		bool _ret;					\
+		local_trylock_t *tl;				\
 								\
 		preempt_disable();				\
-		lt = this_cpu_ptr(lock);			\
-		if (!READ_ONCE(lt->acquired)) {			\
-			WRITE_ONCE(lt->acquired, 1);		\
-			local_trylock_acquire(&lt->llock);	\
-			_ret = true;				\
-		} else {					\
-			_ret = false;				\
+		tl = this_cpu_ptr(lock);			\
+		if (READ_ONCE(tl->acquired)) {			\
 			preempt_enable();			\
+			tl = NULL;				\
+		} else {					\
+			WRITE_ONCE(tl->acquired, 1);		\
+			local_trylock_acquire(			\
+				(local_lock_t *)tl);		\
 		}						\
-		_ret;						\
+		!!tl;						\
 	})
 
-#define __localtry_trylock_irqsave(lock, flags)			\
+#define __local_trylock_irqsave(lock, flags)			\
 	({							\
-		localtry_lock_t *lt;				\
-		bool _ret;					\
+		local_trylock_t *tl;				\
 								\
 		local_irq_save(flags);				\
-		lt = this_cpu_ptr(lock);			\
-		if (!READ_ONCE(lt->acquired)) {			\
-			WRITE_ONCE(lt->acquired, 1);		\
-			local_trylock_acquire(&lt->llock);	\
-			_ret = true;				\
-		} else {					\
-			_ret = false;				\
+		tl = this_cpu_ptr(lock);			\
+		if (READ_ONCE(tl->acquired)) {			\
 			local_irq_restore(flags);		\
+			tl = NULL;				\
+		} else {					\
+			WRITE_ONCE(tl->acquired, 1);		\
+			local_trylock_acquire(			\
+				(local_lock_t *)tl);		\
 		}						\
-		_ret;						\
+		!!tl;						\
 	})
 
-#define __localtry_unlock(lock)					\
+#define __local_lock_release(lock)					\
+	do {								\
+		local_trylock_t *tl;					\
+		local_lock_t *l;					\
+									\
+		l = (local_lock_t *)this_cpu_ptr(lock);			\
+		tl = (local_trylock_t *)l;				\
+		local_lock_release(l);					\
+		_Generic((lock),					\
+			local_trylock_t *: ({				\
+				lockdep_assert(tl->acquired == 1);	\
+				WRITE_ONCE(tl->acquired, 0);		\
+			}),						\
+			default:(void)0);				\
+	} while (0)
+
+#define __local_unlock(lock)					\
 	do {							\
-		localtry_lock_t *lt;				\
-		lt = this_cpu_ptr(lock);			\
-		WRITE_ONCE(lt->acquired, 0);			\
-		local_lock_release(&lt->llock);			\
+		__local_lock_release(lock);			\
 		preempt_enable();				\
 	} while (0)
 
-#define __localtry_unlock_irq(lock)				\
+#define __local_unlock_irq(lock)				\
 	do {							\
-		localtry_lock_t *lt;				\
-		lt = this_cpu_ptr(lock);			\
-		WRITE_ONCE(lt->acquired, 0);			\
-		local_lock_release(&lt->llock);			\
+		__local_lock_release(lock);			\
 		local_irq_enable();				\
 	} while (0)
 
-#define __localtry_unlock_irqrestore(lock, flags)		\
+#define __local_unlock_irqrestore(lock, flags)			\
 	do {							\
-		localtry_lock_t *lt;				\
-		lt = this_cpu_ptr(lock);			\
-		WRITE_ONCE(lt->acquired, 0);			\
-		local_lock_release(&lt->llock);			\
+		__local_lock_release(lock);			\
 		local_irq_restore(flags);			\
 	} while (0)
 
+#define __local_lock_nested_bh(lock)				\
+	do {							\
+		lockdep_assert_in_softirq();			\
+		local_lock_acquire(this_cpu_ptr(lock));	\
+	} while (0)
+
+#define __local_unlock_nested_bh(lock)				\
+	local_lock_release(this_cpu_ptr(lock))
+
 #else /* !CONFIG_PREEMPT_RT */
 
 /*
@@ -237,16 +212,18 @@ do {								\
  * critical section while staying preemptible.
  */
 typedef spinlock_t local_lock_t;
-typedef spinlock_t localtry_lock_t;
+typedef spinlock_t local_trylock_t;
 
 #define INIT_LOCAL_LOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname))
-#define INIT_LOCALTRY_LOCK(lockname) INIT_LOCAL_LOCK(lockname)
+#define INIT_LOCAL_TRYLOCK(lockname) __LOCAL_SPIN_LOCK_UNLOCKED((lockname))
 
 #define __local_lock_init(l)					\
 	do {							\
 		local_spin_lock_init((l));			\
 	} while (0)
 
+#define __local_trylock_init(l)			__local_lock_init(l)
+
 #define __local_lock(__lock)					\
 	do {							\
 		migrate_disable();				\
@@ -283,17 +260,7 @@ do {								\
 	spin_unlock(this_cpu_ptr((lock)));			\
 } while (0)
 
-/* localtry_lock_t variants */
-
-#define __localtry_lock_init(lock)			__local_lock_init(lock)
-#define __localtry_lock(lock)				__local_lock(lock)
-#define __localtry_lock_irq(lock)			__local_lock(lock)
-#define __localtry_lock_irqsave(lock, flags)		__local_lock_irqsave(lock, flags)
-#define __localtry_unlock(lock)				__local_unlock(lock)
-#define __localtry_unlock_irq(lock)			__local_unlock(lock)
-#define __localtry_unlock_irqrestore(lock, flags)	__local_unlock_irqrestore(lock, flags)
-
-#define __localtry_trylock(lock)				\
+#define __local_trylock(lock)					\
 	({							\
 		int __locked;					\
 								\
@@ -308,11 +275,11 @@ do {								\
 		__locked;					\
 	})
 
-#define __localtry_trylock_irqsave(lock, flags)			\
+#define __local_trylock_irqsave(lock, flags)			\
 	({							\
 		typecheck(unsigned long, flags);		\
 		flags = 0;					\
-		__localtry_trylock(lock);			\
+		__local_trylock(lock);				\
 	})
 
 #endif /* CONFIG_PREEMPT_RT */
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index e2b705c14945..b50447ef1c92 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1511,8 +1511,9 @@ static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
 
 /*
  * track_pfn_copy is called when a VM_PFNMAP VMA is about to get the page
- * tables copied during copy_page_range(). On success, stores the pfn to be
- * passed to untrack_pfn_copy().
+ * tables copied during copy_page_range(). Will store the pfn to be
+ * passed to untrack_pfn_copy() only if there is something to be untracked.
+ * Callers should initialize the pfn to 0.
  */
 static inline int track_pfn_copy(struct vm_area_struct *dst_vma,
 		struct vm_area_struct *src_vma, unsigned long *pfn)
@@ -1522,7 +1523,9 @@ static inline int track_pfn_copy(struct vm_area_struct *dst_vma,
 
 /*
  * untrack_pfn_copy is called when a VM_PFNMAP VMA failed to copy during
- * copy_page_range(), but after track_pfn_copy() was already called.
+ * copy_page_range(), but after track_pfn_copy() was already called. Can
+ * be called even if track_pfn_copy() did not actually track anything:
+ * handled internally.
  */
 static inline void untrack_pfn_copy(struct vm_area_struct *dst_vma,
 		unsigned long pfn)