s390/rwlock: use the interlocked-access facility 1 instructions

[karo-tx-linux.git] / arch / s390 / lib / spinlock.c

diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index 01f29bb9c71b929edb2e74a771291026f8007d7a..034a35a3e9c11a0a5a9b7f2d73ba16cf9adbd314 100644 (file)
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -114,6 +114,9 @@ void _raw_read_lock_wait(arch_rwlock_t *rw)
        unsigned int owner, old;
        int count = spin_retry;
 
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+       __RAW_LOCK(&rw->lock, -1, __RAW_OP_ADD);
+#endif
        owner = 0;
        while (1) {
                if (count-- <= 0) {
@@ -147,6 +150,35 @@ int _raw_read_trylock_retry(arch_rwlock_t *rw)
 }
 EXPORT_SYMBOL(_raw_read_trylock_retry);
 
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+
+void _raw_write_lock_wait(arch_rwlock_t *rw, unsigned int prev)
+{
+       unsigned int owner, old;
+       int count = spin_retry;
+
+       owner = 0;
+       while (1) {
+               if (count-- <= 0) {
+                       if (owner && !smp_vcpu_scheduled(~owner))
+                               smp_yield_cpu(~owner);
+                       count = spin_retry;
+               }
+               old = ACCESS_ONCE(rw->lock);
+               owner = ACCESS_ONCE(rw->owner);
+               smp_rmb();
+               if ((int) old >= 0) {
+                       prev = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR);
+                       old = prev;
+               }
+               if ((old & 0x7fffffff) == 0 && (int) prev >= 0)
+                       break;
+       }
+}
+EXPORT_SYMBOL(_raw_write_lock_wait);
+
+#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+
 void _raw_write_lock_wait(arch_rwlock_t *rw)
 {
        unsigned int owner, old, prev;
@@ -173,6 +205,8 @@ void _raw_write_lock_wait(arch_rwlock_t *rw)
 }
 EXPORT_SYMBOL(_raw_write_lock_wait);
 
+#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+
 int _raw_write_trylock_retry(arch_rwlock_t *rw)
 {
        unsigned int old;