1 files changed, 133 insertions, 0 deletions
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
new file mode 100644
index 00000000000..888b5596c19
--- /dev/null
+++ b/arch/s390/lib/spinlock.c
@@ -0,0 +1,133 @@
+/*
+ *  arch/s390/lib/spinlock.c
+ *    Out of line spinlock code.
+ *
+ *  S390 version
+ *    Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ */
+
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <asm/io.h>
+
+atomic_t spin_retry_counter;
+int spin_retry = 1000;
+
+/**
+ * spin_retry= parameter
+ */
+static int __init spin_retry_setup(char *str)
+{
+	spin_retry = simple_strtoul(str, &str, 0);
+	return 1;
+}
+__setup("spin_retry=", spin_retry_setup);
+
+static inline void
+_diag44(void)
+{
+#ifdef __s390x__
+	if (MACHINE_HAS_DIAG44)
+#endif
+		asm volatile("diag 0,0,0x44");
+}
+
+void
+_raw_spin_lock_wait(spinlock_t *lp, unsigned int pc)
+{
+	int count = spin_retry;
+
+	while (1) {
+		if (count-- <= 0) {
+			_diag44();
+			count = spin_retry;
+		}
+		atomic_inc(&spin_retry_counter);
+		if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0)
+			return;
+	}
+}
+EXPORT_SYMBOL(_raw_spin_lock_wait);
+
+int
+_raw_spin_trylock_retry(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)
+			return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(_raw_spin_trylock_retry);
+
+void
+_raw_read_lock_wait(rwlock_t *rw)
+{
+	unsigned int old;
+	int count = spin_retry;
+
+	while (1) {
+		if (count-- <= 0) {
+			_diag44();
+			count = spin_retry;
+		}
+		atomic_inc(&spin_retry_counter);
+		old = rw->lock & 0x7fffffffU;
+		if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
+			return;
+	}
+}
+EXPORT_SYMBOL(_raw_read_lock_wait);
+
+int
+_raw_read_trylock_retry(rwlock_t *rw)
+{
+	unsigned int old;
+	int count = spin_retry;
+
+	while (count-- > 0) {
+		atomic_inc(&spin_retry_counter);
+		old = rw->lock & 0x7fffffffU;
+		if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old)
+			return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(_raw_read_trylock_retry);
+
+void
+_raw_write_lock_wait(rwlock_t *rw)
+{
+	int count = spin_retry;
+
+	while (1) {
+		if (count-- <= 0) {
+			_diag44();
+			count = spin_retry;
+		}
+		atomic_inc(&spin_retry_counter);
+		if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
+			return;
+	}
+}
+EXPORT_SYMBOL(_raw_write_lock_wait);
+
+int
+_raw_write_trylock_retry(rwlock_t *rw)
+{
+	int count = spin_retry;
+
+	while (count-- > 0) {
+		atomic_inc(&spin_retry_counter);
+		if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0)
+			return 1;
+	}
+	return 0;
+}
+EXPORT_SYMBOL(_raw_write_trylock_retry);