[S390] implement interrupt-enabling rwlocks

arch backend for f5f7eac41db827a47b2163330eecd7bb55ae9f12
"Allow rwlocks to re-enable interrupts".

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 40 insertions, 0 deletions

diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index e41f4008afc5..f7e0d30250b7 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -124,6 +124,27 @@ void _raw_read_lock_wait(raw_rwlock_t *rw)
 }
 EXPORT_SYMBOL(_raw_read_lock_wait);
 
+void _raw_read_lock_wait_flags(raw_rwlock_t *rw, unsigned long flags)
+{
+	unsigned int old;
+	int count = spin_retry;
+
+	local_irq_restore(flags);
+	while (1) {
+		if (count-- <= 0) {
+			_raw_yield();
+			count = spin_retry;
+		}
+		if (!__raw_read_can_lock(rw))
+			continue;
+		old = rw->lock & 0x7fffffffU;
+		local_irq_disable();
+		if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
+			return;
+	}
+}
+EXPORT_SYMBOL(_raw_read_lock_wait_flags);
+
 int _raw_read_trylock_retry(raw_rwlock_t *rw)
 {
 	unsigned int old;
@@ -157,6 +178,25 @@ void _raw_write_lock_wait(raw_rwlock_t *rw)
 }
 EXPORT_SYMBOL(_raw_write_lock_wait);
 
+void _raw_write_lock_wait_flags(raw_rwlock_t *rw, unsigned long flags)
+{
+	int count = spin_retry;
+
+	local_irq_restore(flags);
+	while (1) {
+		if (count-- <= 0) {
+			_raw_yield();
+			count = spin_retry;
+		}
+		if (!__raw_write_can_lock(rw))
+			continue;
+		local_irq_disable();
+		if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
+			return;
+	}
+}
+EXPORT_SYMBOL(_raw_write_lock_wait_flags);
+
 int _raw_write_trylock_retry(raw_rwlock_t *rw)
 {
 	int count = spin_retry;