X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fs390%2Flib%2Fspinlock.c;h=8d76403fcf89b5900f02f6084312049791b8dc4e;hb=0f166396e7e8931bb4acfd1a6ea1bd4f0b43f1dd;hp=2dc14e9c83276818f95afa4d054e1f836fec4774;hpb=38a9a621aba953ddb8051547e98c10ec3c741312;p=linux-2.6

diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index 2dc14e9c83..8d76403fcf 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -2,8 +2,7 @@
  *  arch/s390/lib/spinlock.c
  *    Out of line spinlock code.
  *
- *  S390 version
- *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Copyright (C) IBM Corp. 2004, 2006
  *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
  */
 
@@ -13,7 +12,6 @@
 #include <linux/init.h>
 #include <asm/io.h>
 
-atomic_t spin_retry_counter;
 int spin_retry = 1000;
 
 /**
@@ -26,58 +24,80 @@ static int __init spin_retry_setup(char *str)
 }
 __setup("spin_retry=", spin_retry_setup);
 
-static inline void
-_diag44(void)
+static inline void _raw_yield(void)
 {
-#ifdef __s390x__
 	if (MACHINE_HAS_DIAG44)
-#endif
 		asm volatile("diag 0,0,0x44");
 }
 
-void
-_raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc)
+static inline void _raw_yield_cpu(int cpu)
+{
+	if (MACHINE_HAS_DIAG9C)
+		asm volatile("diag %0,0,0x9c"
+			     : : "d" (__cpu_logical_map[cpu]));
+	else
+		_raw_yield();
+}
+
+void _raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc)
 {
 	int count = spin_retry;
+	unsigned int cpu = ~smp_processor_id();
 
 	while (1) {
 		if (count-- <= 0) {
-			_diag44();
+			unsigned int owner = lp->owner_cpu;
+			if (owner != 0)
+				_raw_yield_cpu(~owner);
 			count = spin_retry;
 		}
-		atomic_inc(&spin_retry_counter);
-		if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0)
+		if (__raw_spin_is_locked(lp))
+			continue;
+		if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) {
+			lp->owner_pc = pc;
 			return;
+		}
 	}
 }
 EXPORT_SYMBOL(_raw_spin_lock_wait);
 
-int
-_raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc)
+int _raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc)
 {
-	int count = spin_retry;
-
-	while (count-- > 0) {
-		atomic_inc(&spin_retry_counter);
-		if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0)
+	unsigned int cpu = ~smp_processor_id();
+	int count;
+
+	for (count = spin_retry; count > 0; count--) {
+		if (__raw_spin_is_locked(lp))
+			continue;
+		if (_raw_compare_and_swap(&lp->owner_cpu, 0, cpu) == 0) {
+			lp->owner_pc = pc;
 			return 1;
+		}
 	}
 	return 0;
 }
 EXPORT_SYMBOL(_raw_spin_trylock_retry);
 
-void
-_raw_read_lock_wait(raw_rwlock_t *rw)
+void _raw_spin_relax(raw_spinlock_t *lock)
+{
+	unsigned int cpu = lock->owner_cpu;
+	if (cpu != 0)
+		_raw_yield_cpu(~cpu);
+}
+EXPORT_SYMBOL(_raw_spin_relax);
+
+void _raw_read_lock_wait(raw_rwlock_t *rw)
 {
 	unsigned int old;
 	int count = spin_retry;
 
 	while (1) {
 		if (count-- <= 0) {
-			_diag44();
+			_raw_yield();
 			count = spin_retry;
 		}
-		atomic_inc(&spin_retry_counter);
+		if (!__raw_read_can_lock(rw))
+			continue;
 		old = rw->lock & 0x7fffffffU;
 		if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
 			return;
@@ -85,14 +105,14 @@ _raw_read_lock_wait(raw_rwlock_t *rw)
 }
 EXPORT_SYMBOL(_raw_read_lock_wait);
 
-int
-_raw_read_trylock_retry(raw_rwlock_t *rw)
+int _raw_read_trylock_retry(raw_rwlock_t *rw)
 {
 	unsigned int old;
 	int count = spin_retry;
 
 	while (count-- > 0) {
-		atomic_inc(&spin_retry_counter);
+		if (!__raw_read_can_lock(rw))
+			continue;
 		old = rw->lock & 0x7fffffffU;
 		if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
 			return 1;
@@ -101,30 +121,30 @@ _raw_read_trylock_retry(raw_rwlock_t *rw)
 }
 EXPORT_SYMBOL(_raw_read_trylock_retry);
 
-void
-_raw_write_lock_wait(raw_rwlock_t *rw)
+void _raw_write_lock_wait(raw_rwlock_t *rw)
 {
 	int count = spin_retry;
 
 	while (1) {
 		if (count-- <= 0) {
-			_diag44();
+			_raw_yield();
 			count = spin_retry;
 		}
-		atomic_inc(&spin_retry_counter);
+		if (!__raw_write_can_lock(rw))
+			continue;
 		if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
 			return;
 	}
 }
 EXPORT_SYMBOL(_raw_write_lock_wait);
 
-int
-_raw_write_trylock_retry(raw_rwlock_t *rw)
+int _raw_write_trylock_retry(raw_rwlock_t *rw)
 {
 	int count = spin_retry;
 
 	while (count-- > 0) {
-		atomic_inc(&spin_retry_counter);
+		if (!__raw_write_can_lock(rw))
+			continue;
 		if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
 			return 1;
 	}