1 files changed, 163 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/spinlock.h b/arch/alpha/include/asm/spinlock.h
new file mode 100644
index 0000000000..1221cbb86a
--- /dev/null
+++ b/arch/alpha/include/asm/spinlock.h
@@ -0,0 +1,163 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ALPHA_SPINLOCK_H
+#define _ALPHA_SPINLOCK_H
+
+#include <linux/kernel.h>
+#include <asm/current.h>
+#include <asm/barrier.h>
+#include <asm/processor.h>
+
+/*
+ * Simple spin lock operations.  There are two variants, one clears IRQ's
+ * on the local processor, one does not.
+ *
+ * We make no fairness assumptions. They have a cost.
+ */
+
+#define arch_spin_is_locked(x)	((x)->lock != 0)
+
+static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
+{
+        return lock.lock == 0;
+}
+
+static inline void arch_spin_unlock(arch_spinlock_t * lock)
+{
+	mb();
+	lock->lock = 0;
+}
+
+static inline void arch_spin_lock(arch_spinlock_t * lock)
+{
+	long tmp;
+
+	__asm__ __volatile__(
+	"1:	ldl_l	%0,%1\n"
+	"	bne	%0,2f\n"
+	"	lda	%0,1\n"
+	"	stl_c	%0,%1\n"
+	"	beq	%0,2f\n"
+	"	mb\n"
+	".subsection 2\n"
+	"2:	ldl	%0,%1\n"
+	"	bne	%0,2b\n"
+	"	br	1b\n"
+	".previous"
+	: "=&r" (tmp), "=m" (lock->lock)
+	: "m"(lock->lock) : "memory");
+}
+
+static inline int arch_spin_trylock(arch_spinlock_t *lock)
+{
+	return !test_and_set_bit(0, &lock->lock);
+}
+
+/***********************************************************/
+
+static inline void arch_read_lock(arch_rwlock_t *lock)
+{
+	long regx;
+
+	__asm__ __volatile__(
+	"1:	ldl_l	%1,%0\n"
+	"	blbs	%1,6f\n"
+	"	subl	%1,2,%1\n"
+	"	stl_c	%1,%0\n"
+	"	beq	%1,6f\n"
+	"	mb\n"
+	".subsection 2\n"
+	"6:	ldl	%1,%0\n"
+	"	blbs	%1,6b\n"
+	"	br	1b\n"
+	".previous"
+	: "=m" (*lock), "=&r" (regx)
+	: "m" (*lock) : "memory");
+}
+
+static inline void arch_write_lock(arch_rwlock_t *lock)
+{
+	long regx;
+
+	__asm__ __volatile__(
+	"1:	ldl_l	%1,%0\n"
+	"	bne	%1,6f\n"
+	"	lda	%1,1\n"
+	"	stl_c	%1,%0\n"
+	"	beq	%1,6f\n"
+	"	mb\n"
+	".subsection 2\n"
+	"6:	ldl	%1,%0\n"
+	"	bne	%1,6b\n"
+	"	br	1b\n"
+	".previous"
+	: "=m" (*lock), "=&r" (regx)
+	: "m" (*lock) : "memory");
+}
+
+static inline int arch_read_trylock(arch_rwlock_t * lock)
+{
+	long regx;
+	int success;
+
+	__asm__ __volatile__(
+	"1:	ldl_l	%1,%0\n"
+	"	lda	%2,0\n"
+	"	blbs	%1,2f\n"
+	"	subl	%1,2,%2\n"
+	"	stl_c	%2,%0\n"
+	"	beq	%2,6f\n"
+	"2:	mb\n"
+	".subsection 2\n"
+	"6:	br	1b\n"
+	".previous"
+	: "=m" (*lock), "=&r" (regx), "=&r" (success)
+	: "m" (*lock) : "memory");
+
+	return success;
+}
+
+static inline int arch_write_trylock(arch_rwlock_t * lock)
+{
+	long regx;
+	int success;
+
+	__asm__ __volatile__(
+	"1:	ldl_l	%1,%0\n"
+	"	lda	%2,0\n"
+	"	bne	%1,2f\n"
+	"	lda	%2,1\n"
+	"	stl_c	%2,%0\n"
+	"	beq	%2,6f\n"
+	"2:	mb\n"
+	".subsection 2\n"
+	"6:	br	1b\n"
+	".previous"
+	: "=m" (*lock), "=&r" (regx), "=&r" (success)
+	: "m" (*lock) : "memory");
+
+	return success;
+}
+
+static inline void arch_read_unlock(arch_rwlock_t * lock)
+{
+	long regx;
+	__asm__ __volatile__(
+	"	mb\n"
+	"1:	ldl_l	%1,%0\n"
+	"	addl	%1,2,%1\n"
+	"	stl_c	%1,%0\n"
+	"	beq	%1,6f\n"
+	".subsection 2\n"
+	"6:	br	1b\n"
+	".previous"
+	: "=m" (*lock), "=&r" (regx)
+	: "m" (*lock) : "memory");
+}
+
+static inline void arch_write_unlock(arch_rwlock_t * lock)
+{
+	mb();
+	lock->lock = 0;
+}
+
+#endif /* _ALPHA_SPINLOCK_H */