[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;