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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-ppc/spinlock.h
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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-ppc/spinlock.h')
-rw-r--r--include/asm-ppc/spinlock.h215
1 files changed, 215 insertions, 0 deletions
diff --git a/include/asm-ppc/spinlock.h b/include/asm-ppc/spinlock.h
new file mode 100644
index 000000000000..909199aae104
--- /dev/null
+++ b/include/asm-ppc/spinlock.h
@@ -0,0 +1,215 @@
+#ifndef __ASM_SPINLOCK_H
+#define __ASM_SPINLOCK_H
+
+#include <asm/system.h>
+
+/*
+ * Simple spin lock operations.
+ */
+
+typedef struct {
+ volatile unsigned long lock;
+#ifdef CONFIG_DEBUG_SPINLOCK
+ volatile unsigned long owner_pc;
+ volatile unsigned long owner_cpu;
+#endif
+#ifdef CONFIG_PREEMPT
+ unsigned int break_lock;
+#endif
+} spinlock_t;
+
+#ifdef __KERNEL__
+#ifdef CONFIG_DEBUG_SPINLOCK
+#define SPINLOCK_DEBUG_INIT , 0, 0
+#else
+#define SPINLOCK_DEBUG_INIT /* */
+#endif
+
+#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 SPINLOCK_DEBUG_INIT }
+
+#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(spin_is_locked(x))
+#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+
+#ifndef CONFIG_DEBUG_SPINLOCK
+
+static inline void _raw_spin_lock(spinlock_t *lock)
+{
+ unsigned long tmp;
+
+ __asm__ __volatile__(
+ "b 1f # spin_lock\n\
+2: lwzx %0,0,%1\n\
+ cmpwi 0,%0,0\n\
+ bne+ 2b\n\
+1: lwarx %0,0,%1\n\
+ cmpwi 0,%0,0\n\
+ bne- 2b\n"
+ PPC405_ERR77(0,%1)
+" stwcx. %2,0,%1\n\
+ bne- 2b\n\
+ isync"
+ : "=&r"(tmp)
+ : "r"(&lock->lock), "r"(1)
+ : "cr0", "memory");
+}
+
+static inline void _raw_spin_unlock(spinlock_t *lock)
+{
+ __asm__ __volatile__("eieio # spin_unlock": : :"memory");
+ lock->lock = 0;
+}
+
+#define _raw_spin_trylock(l) (!test_and_set_bit(0,&(l)->lock))
+
+#else
+
+extern void _raw_spin_lock(spinlock_t *lock);
+extern void _raw_spin_unlock(spinlock_t *lock);
+extern int _raw_spin_trylock(spinlock_t *lock);
+
+#endif
+
+/*
+ * Read-write spinlocks, allowing multiple readers
+ * but only one writer.
+ *
+ * NOTE! it is quite common to have readers in interrupts
+ * but no interrupt writers. For those circumstances we
+ * can "mix" irq-safe locks - any writer needs to get a
+ * irq-safe write-lock, but readers can get non-irqsafe
+ * read-locks.
+ */
+typedef struct {
+ volatile signed int lock;
+#ifdef CONFIG_PREEMPT
+ unsigned int break_lock;
+#endif
+} rwlock_t;
+
+#define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
+#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
+
+#define read_can_lock(rw) ((rw)->lock >= 0)
+#define write_can_lock(rw) (!(rw)->lock)
+
+#ifndef CONFIG_DEBUG_SPINLOCK
+
+static __inline__ int _raw_read_trylock(rwlock_t *rw)
+{
+ signed int tmp;
+
+ __asm__ __volatile__(
+"2: lwarx %0,0,%1 # read_trylock\n\
+ addic. %0,%0,1\n\
+ ble- 1f\n"
+ PPC405_ERR77(0,%1)
+" stwcx. %0,0,%1\n\
+ bne- 2b\n\
+ isync\n\
+1:"
+ : "=&r"(tmp)
+ : "r"(&rw->lock)
+ : "cr0", "memory");
+
+ return tmp > 0;
+}
+
+static __inline__ void _raw_read_lock(rwlock_t *rw)
+{
+ signed int tmp;
+
+ __asm__ __volatile__(
+ "b 2f # read_lock\n\
+1: lwzx %0,0,%1\n\
+ cmpwi 0,%0,0\n\
+ blt+ 1b\n\
+2: lwarx %0,0,%1\n\
+ addic. %0,%0,1\n\
+ ble- 1b\n"
+ PPC405_ERR77(0,%1)
+" stwcx. %0,0,%1\n\
+ bne- 2b\n\
+ isync"
+ : "=&r"(tmp)
+ : "r"(&rw->lock)
+ : "cr0", "memory");
+}
+
+static __inline__ void _raw_read_unlock(rwlock_t *rw)
+{
+ signed int tmp;
+
+ __asm__ __volatile__(
+ "eieio # read_unlock\n\
+1: lwarx %0,0,%1\n\
+ addic %0,%0,-1\n"
+ PPC405_ERR77(0,%1)
+" stwcx. %0,0,%1\n\
+ bne- 1b"
+ : "=&r"(tmp)
+ : "r"(&rw->lock)
+ : "cr0", "memory");
+}
+
+static __inline__ int _raw_write_trylock(rwlock_t *rw)
+{
+ signed int tmp;
+
+ __asm__ __volatile__(
+"2: lwarx %0,0,%1 # write_trylock\n\
+ cmpwi 0,%0,0\n\
+ bne- 1f\n"
+ PPC405_ERR77(0,%1)
+" stwcx. %2,0,%1\n\
+ bne- 2b\n\
+ isync\n\
+1:"
+ : "=&r"(tmp)
+ : "r"(&rw->lock), "r"(-1)
+ : "cr0", "memory");
+
+ return tmp == 0;
+}
+
+static __inline__ void _raw_write_lock(rwlock_t *rw)
+{
+ signed int tmp;
+
+ __asm__ __volatile__(
+ "b 2f # write_lock\n\
+1: lwzx %0,0,%1\n\
+ cmpwi 0,%0,0\n\
+ bne+ 1b\n\
+2: lwarx %0,0,%1\n\
+ cmpwi 0,%0,0\n\
+ bne- 1b\n"
+ PPC405_ERR77(0,%1)
+" stwcx. %2,0,%1\n\
+ bne- 2b\n\
+ isync"
+ : "=&r"(tmp)
+ : "r"(&rw->lock), "r"(-1)
+ : "cr0", "memory");
+}
+
+static __inline__ void _raw_write_unlock(rwlock_t *rw)
+{
+ __asm__ __volatile__("eieio # write_unlock": : :"memory");
+ rw->lock = 0;
+}
+
+#else
+
+extern void _raw_read_lock(rwlock_t *rw);
+extern void _raw_read_unlock(rwlock_t *rw);
+extern void _raw_write_lock(rwlock_t *rw);
+extern void _raw_write_unlock(rwlock_t *rw);
+extern int _raw_read_trylock(rwlock_t *rw);
+extern int _raw_write_trylock(rwlock_t *rw);
+
+#endif
+
+#endif /* __ASM_SPINLOCK_H */
+#endif /* __KERNEL__ */