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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-alpha/spinlock.h
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'include/asm-alpha/spinlock.h')
-rw-r--r--include/asm-alpha/spinlock.h212
1 files changed, 212 insertions, 0 deletions
diff --git a/include/asm-alpha/spinlock.h b/include/asm-alpha/spinlock.h
new file mode 100644
index 000000000000..80780dba9986
--- /dev/null
+++ b/include/asm-alpha/spinlock.h
@@ -0,0 +1,212 @@
+#ifndef _ALPHA_SPINLOCK_H
+#define _ALPHA_SPINLOCK_H
+
+#include <linux/config.h>
+#include <asm/system.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.
+ */
+
+typedef struct {
+ volatile unsigned int lock;
+#ifdef CONFIG_DEBUG_SPINLOCK
+ int on_cpu;
+ int line_no;
+ void *previous;
+ struct task_struct * task;
+ const char *base_file;
+#endif
+} spinlock_t;
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0, -1, 0, NULL, NULL, NULL }
+#else
+#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0 }
+#endif
+
+#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
+#define spin_is_locked(x) ((x)->lock != 0)
+#define spin_unlock_wait(x) do { barrier(); } while ((x)->lock)
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+extern void _raw_spin_unlock(spinlock_t * lock);
+extern void debug_spin_lock(spinlock_t * lock, const char *, int);
+extern int debug_spin_trylock(spinlock_t * lock, const char *, int);
+#define _raw_spin_lock(LOCK) \
+ debug_spin_lock(LOCK, __BASE_FILE__, __LINE__)
+#define _raw_spin_trylock(LOCK) \
+ debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__)
+#else
+static inline void _raw_spin_unlock(spinlock_t * lock)
+{
+ mb();
+ lock->lock = 0;
+}
+
+static inline void _raw_spin_lock(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 _raw_spin_trylock(spinlock_t *lock)
+{
+ return !test_and_set_bit(0, &lock->lock);
+}
+#endif /* CONFIG_DEBUG_SPINLOCK */
+
+#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+
+/***********************************************************/
+
+typedef struct {
+ volatile unsigned int lock;
+} rwlock_t;
+
+#define RW_LOCK_UNLOCKED (rwlock_t){ 0 }
+
+#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
+
+static inline int read_can_lock(rwlock_t *lock)
+{
+ return (lock->lock & 1) == 0;
+}
+
+static inline int write_can_lock(rwlock_t *lock)
+{
+ return lock->lock == 0;
+}
+
+#ifdef CONFIG_DEBUG_RWLOCK
+extern void _raw_write_lock(rwlock_t * lock);
+extern void _raw_read_lock(rwlock_t * lock);
+#else
+static inline void _raw_write_lock(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 void _raw_read_lock(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");
+}
+#endif /* CONFIG_DEBUG_RWLOCK */
+
+static inline int _raw_read_trylock(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 _raw_write_trylock(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 _raw_write_unlock(rwlock_t * lock)
+{
+ mb();
+ lock->lock = 0;
+}
+
+static inline void _raw_read_unlock(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");
+}
+
+#endif /* _ALPHA_SPINLOCK_H */