Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / alpha / include / asm / spinlock.h

diff --git a/kernel/arch/alpha/include/asm/spinlock.h b/kernel/arch/alpha/include/asm/spinlock.h
new file mode 100644 (file)
index 0000000..37b570d
--- /dev/null
+++ b/kernel/arch/alpha/include/asm/spinlock.h
@@ -0,0 +1,171 @@
+#ifndef _ALPHA_SPINLOCK_H
+#define _ALPHA_SPINLOCK_H
+
+#include <linux/kernel.h>
+#include <asm/current.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_lock_flags(lock, flags) arch_spin_lock(lock)
+#define arch_spin_is_locked(x) ((x)->lock != 0)
+#define arch_spin_unlock_wait(x) \
+               do { cpu_relax(); } while ((x)->lock)
+
+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 int arch_read_can_lock(arch_rwlock_t *lock)
+{
+       return (lock->lock & 1) == 0;
+}
+
+static inline int arch_write_can_lock(arch_rwlock_t *lock)
+{
+       return lock->lock == 0;
+}
+
+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;
+}
+
+#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
+#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
+
+#endif /* _ALPHA_SPINLOCK_H */