s390/spinlock: use atomic primitives for spinlocks

Add a couple more __atomic_xxx function to atomic_ops.h and use them
to replace the compare-and-swap inlines in the spinlock code. This
changes the type of the lock value from unsigned int to int.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 35 insertions, 38 deletions

diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index ba427eb6f14c..3f4d0c69bbfe 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -32,23 +32,22 @@ static int __init spin_retry_setup(char *str)
 }
 __setup("spin_retry=", spin_retry_setup);
 
-static inline void _raw_compare_and_delay(unsigned int *lock, unsigned int old)
+static inline void compare_and_delay(int *lock, int old)
 {
 	asm(".insn rsy,0xeb0000000022,%0,0,%1" : : "d" (old), "Q" (*lock));
 }
 
 void arch_spin_lock_wait(arch_spinlock_t *lp)
 {
-	unsigned int cpu = SPINLOCK_LOCKVAL;
-	unsigned int owner;
-	int count, first_diag;
+	int cpu = SPINLOCK_LOCKVAL;
+	int owner, count, first_diag;
 
 	first_diag = 1;
 	while (1) {
 		owner = ACCESS_ONCE(lp->lock);
 		/* Try to get the lock if it is free. */
 		if (!owner) {
-			if (_raw_compare_and_swap(&lp->lock, 0, cpu))
+			if (__atomic_cmpxchg_bool(&lp->lock, 0, cpu))
 				return;
 			continue;
 		}
@@ -62,7 +61,7 @@ void arch_spin_lock_wait(arch_spinlock_t *lp)
 		count = spin_retry;
 		do {
 			if (MACHINE_HAS_CAD)
-				_raw_compare_and_delay(&lp->lock, owner);
+				compare_and_delay(&lp->lock, owner);
 			owner = ACCESS_ONCE(lp->lock);
 		} while (owner && count-- > 0);
 		if (!owner)
@@ -82,9 +81,8 @@ EXPORT_SYMBOL(arch_spin_lock_wait);
 
 void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
 {
-	unsigned int cpu = SPINLOCK_LOCKVAL;
-	unsigned int owner;
-	int count, first_diag;
+	int cpu = SPINLOCK_LOCKVAL;
+	int owner, count, first_diag;
 
 	local_irq_restore(flags);
 	first_diag = 1;
@@ -93,7 +91,7 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
 		/* Try to get the lock if it is free. */
 		if (!owner) {
 			local_irq_disable();
-			if (_raw_compare_and_swap(&lp->lock, 0, cpu))
+			if (__atomic_cmpxchg_bool(&lp->lock, 0, cpu))
 				return;
 			local_irq_restore(flags);
 			continue;
@@ -108,7 +106,7 @@ void arch_spin_lock_wait_flags(arch_spinlock_t *lp, unsigned long flags)
 		count = spin_retry;
 		do {
 			if (MACHINE_HAS_CAD)
-				_raw_compare_and_delay(&lp->lock, owner);
+				compare_and_delay(&lp->lock, owner);
 			owner = ACCESS_ONCE(lp->lock);
 		} while (owner && count-- > 0);
 		if (!owner)
@@ -128,18 +126,17 @@ EXPORT_SYMBOL(arch_spin_lock_wait_flags);
 
 int arch_spin_trylock_retry(arch_spinlock_t *lp)
 {
-	unsigned int cpu = SPINLOCK_LOCKVAL;
-	unsigned int owner;
-	int count;
+	int cpu = SPINLOCK_LOCKVAL;
+	int owner, count;
 
 	for (count = spin_retry; count > 0; count--) {
 		owner = READ_ONCE(lp->lock);
 		/* Try to get the lock if it is free. */
 		if (!owner) {
-			if (_raw_compare_and_swap(&lp->lock, 0, cpu))
+			if (__atomic_cmpxchg_bool(&lp->lock, 0, cpu))
 				return 1;
 		} else if (MACHINE_HAS_CAD)
-			_raw_compare_and_delay(&lp->lock, owner);
+			compare_and_delay(&lp->lock, owner);
 	}
 	return 0;
 }
@@ -147,8 +144,8 @@ EXPORT_SYMBOL(arch_spin_trylock_retry);
 
 void _raw_read_lock_wait(arch_rwlock_t *rw)
 {
-	unsigned int owner, old;
 	int count = spin_retry;
+	int owner, old;
 
 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 	__RAW_LOCK(&rw->lock, -1, __RAW_OP_ADD);
@@ -162,12 +159,12 @@ void _raw_read_lock_wait(arch_rwlock_t *rw)
 		}
 		old = ACCESS_ONCE(rw->lock);
 		owner = ACCESS_ONCE(rw->owner);
-		if ((int) old < 0) {
+		if (old < 0) {
 			if (MACHINE_HAS_CAD)
-				_raw_compare_and_delay(&rw->lock, old);
+				compare_and_delay(&rw->lock, old);
 			continue;
 		}
-		if (_raw_compare_and_swap(&rw->lock, old, old + 1))
+		if (__atomic_cmpxchg_bool(&rw->lock, old, old + 1))
 			return;
 	}
 }
@@ -175,17 +172,17 @@ EXPORT_SYMBOL(_raw_read_lock_wait);
 
 int _raw_read_trylock_retry(arch_rwlock_t *rw)
 {
-	unsigned int old;
 	int count = spin_retry;
+	int old;
 
 	while (count-- > 0) {
 		old = ACCESS_ONCE(rw->lock);
-		if ((int) old < 0) {
+		if (old < 0) {
 			if (MACHINE_HAS_CAD)
-				_raw_compare_and_delay(&rw->lock, old);
+				compare_and_delay(&rw->lock, old);
 			continue;
 		}
-		if (_raw_compare_and_swap(&rw->lock, old, old + 1))
+		if (__atomic_cmpxchg_bool(&rw->lock, old, old + 1))
 			return 1;
 	}
 	return 0;
@@ -194,10 +191,10 @@ EXPORT_SYMBOL(_raw_read_trylock_retry);
 
 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
 
-void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev)
+void _raw_write_lock_wait(arch_rwlock_t *rw, int prev)
 {
-	unsigned int owner, old;
 	int count = spin_retry;
+	int owner, old;
 
 	owner = 0;
 	while (1) {
@@ -209,14 +206,14 @@ void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev)
 		old = ACCESS_ONCE(rw->lock);
 		owner = ACCESS_ONCE(rw->owner);
 		smp_mb();
-		if ((int) old >= 0) {
+		if (old >= 0) {
 			prev = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR);
 			old = prev;
 		}
-		if ((old & 0x7fffffff) == 0 && (int) prev >= 0)
+		if ((old & 0x7fffffff) == 0 && prev >= 0)
 			break;
 		if (MACHINE_HAS_CAD)
-			_raw_compare_and_delay(&rw->lock, old);
+			compare_and_delay(&rw->lock, old);
 	}
 }
 EXPORT_SYMBOL(_raw_write_lock_wait);
@@ -225,8 +222,8 @@ EXPORT_SYMBOL(_raw_write_lock_wait);
 
 void _raw_write_lock_wait(arch_rwlock_t *rw)
 {
-	unsigned int owner, old, prev;
 	int count = spin_retry;
+	int owner, old, prev;
 
 	prev = 0x80000000;
 	owner = 0;
@@ -238,15 +235,15 @@ void _raw_write_lock_wait(arch_rwlock_t *rw)
 		}
 		old = ACCESS_ONCE(rw->lock);
 		owner = ACCESS_ONCE(rw->owner);
-		if ((int) old >= 0 &&
-		    _raw_compare_and_swap(&rw->lock, old, old | 0x80000000))
+		if (old >= 0 &&
+		    __atomic_cmpxchg_bool(&rw->lock, old, old | 0x80000000))
 			prev = old;
 		else
 			smp_mb();
-		if ((old & 0x7fffffff) == 0 && (int) prev >= 0)
+		if ((old & 0x7fffffff) == 0 && prev >= 0)
 			break;
 		if (MACHINE_HAS_CAD)
-			_raw_compare_and_delay(&rw->lock, old);
+			compare_and_delay(&rw->lock, old);
 	}
 }
 EXPORT_SYMBOL(_raw_write_lock_wait);
@@ -255,24 +252,24 @@ EXPORT_SYMBOL(_raw_write_lock_wait);
 
 int _raw_write_trylock_retry(arch_rwlock_t *rw)
 {
-	unsigned int old;
 	int count = spin_retry;
+	int old;
 
 	while (count-- > 0) {
 		old = ACCESS_ONCE(rw->lock);
 		if (old) {
 			if (MACHINE_HAS_CAD)
-				_raw_compare_and_delay(&rw->lock, old);
+				compare_and_delay(&rw->lock, old);
 			continue;
 		}
-		if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000))
+		if (__atomic_cmpxchg_bool(&rw->lock, 0, 0x80000000))
 			return 1;
 	}
 	return 0;
 }
 EXPORT_SYMBOL(_raw_write_trylock_retry);
 
-void arch_lock_relax(unsigned int cpu)
+void arch_lock_relax(int cpu)
 {
 	if (!cpu)
 		return;