/*
* Simple spin lock operations.
*
- * Copyright (C) 2001 Paul Mackerras <paulus@au.ibm.com>, IBM
+ * Copyright (C) 2001
-2004 Paul Mackerras <paulus@au.ibm.com>, IBM
* Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
*
* Type of int is used as a full 64b word is not necessary.
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
+#include <linux/config.h>
+
typedef struct {
volatile unsigned int lock;
} spinlock_t;
#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
#define spin_is_locked(x) ((x)->lock != 0)
+#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
+
+static __inline__ void _raw_spin_unlock(spinlock_t *lock)
+{
+ __asm__ __volatile__("lwsync # spin_unlock": : :"memory");
+ lock->lock = 0;
+}
+
+/*
+ * Normally we use the spinlock functions in arch/ppc64/lib/locks.c.
+ * For special applications such as profiling, we can have the
+ * spinlock functions inline by defining CONFIG_SPINLINE.
+ * This is not recommended on partitioned systems with shared
+ * processors, since the inline spinlock functions don't include
+ * the code for yielding the CPU to the lock holder.
+ */
+
+#ifndef CONFIG_SPINLINE
+extern int _raw_spin_trylock(spinlock_t *lock);
+extern void _raw_spin_lock(spinlock_t *lock);
+extern void _raw_spin_lock_flags(spinlock_t *lock, unsigned long flags);
+extern void spin_unlock_wait(spinlock_t *lock);
+
+#else
static __inline__ int _raw_spin_trylock(spinlock_t *lock)
{
- unsigned int tmp;
+ unsigned int tmp, tmp2;
__asm__ __volatile__(
-"1: lwarx %0,0,%1 # spin_trylock\n\
+"1: lwarx %0,0,%2 # spin_trylock\n\
cmpwi 0,%0,0\n\
- li %0,0\n\
bne- 2f\n\
- li %0,1\n\
- stwcx. %0,0,%1\n\
+ lwz %1,24(13)\n\
+ stwcx. %1,0,%2\n\
bne- 1b\n\
isync\n\
-2:" : "=&r"(tmp)
+2:" : "=&r"(tmp), "=&r"(tmp2)
: "r"(&lock->lock)
: "cr0", "memory");
- return tmp;
+ return tmp == 0;
}
static __inline__ void _raw_spin_lock(spinlock_t *lock)
"2: lwarx %0,0,%1\n\
cmpwi 0,%0,0\n\
bne- 1b\n\
- stwcx. %2,0,%1\n\
+ lwz %0,24(13)\n\
+ stwcx. %0,0,%1\n\
bne- 2b\n\
isync"
: "=&r"(tmp)
- : "r"(&lock->lock), "r"(1)
+ : "r"(&lock->lock)
: "cr0", "memory");
}
-static __inline__ void _raw_spin_unlock(spinlock_t *lock)
+/*
+ * Note: if we ever want to inline the spinlocks on iSeries,
+ * we will have to change the irq enable/disable stuff in here.
+ */
+static __inline__ void _raw_spin_lock_flags(spinlock_t *lock,
+ unsigned long flags)
{
- __asm__ __volatile__("eieio # spin_unlock": : :"memory");
- lock->lock = 0;
+ unsigned int tmp;
+ unsigned long tmp2;
+
+ __asm__ __volatile__(
+ "b 3f # spin_lock\n\
+1: mfmsr %1\n\
+ mtmsrd %3,1\n\
+2:" HMT_LOW
+" lwzx %0,0,%2\n\
+ cmpwi 0,%0,0\n\
+ bne+ 2b\n"
+ HMT_MEDIUM
+" mtmsrd %1,1\n\
+3: lwarx %0,0,%2\n\
+ cmpwi 0,%0,0\n\
+ bne- 1b\n\
+ lwz %1,24(13)\n\
+ stwcx. %1,0,%2\n\
+ bne- 3b\n\
+ isync"
+ : "=&r"(tmp), "=&r"(tmp2)
+ : "r"(&lock->lock), "r"(flags)
+ : "cr0", "memory");
}
+#define spin_unlock_wait(x) do { cpu_relax(); } while (spin_is_locked(x))
+
+#endif /* CONFIG_SPINLINE */
+
/*
* Read-write spinlocks, allowing multiple readers
* but only one writer.
#define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
+#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
+#define rwlock_is_locked(x) ((x)->lock)
+
+static __inline__ int is_read_locked(rwlock_t *rw)
+{
+ return rw->lock > 0;
+}
+
+static __inline__ int is_write_locked(rwlock_t *rw)
+{
+ return rw->lock < 0;
+}
+
+static __inline__ void _raw_write_unlock(rwlock_t *rw)
+{
+ __asm__ __volatile__("lwsync # write_unlock": : :"memory");
+ rw->lock = 0;
+}
+
+#ifndef CONFIG_SPINLINE
+extern int _raw_read_trylock(rwlock_t *rw);
+extern void _raw_read_lock(rwlock_t *rw);
+extern void _raw_read_unlock(rwlock_t *rw);
+extern int _raw_write_trylock(rwlock_t *rw);
+extern void _raw_write_lock(rwlock_t *rw);
+extern void _raw_write_unlock(rwlock_t *rw);
+
+#else
static __inline__ int _raw_read_trylock(rwlock_t *rw)
{
unsigned int tmp;
unsigned int tmp;
__asm__ __volatile__(
- "eieio # read_unlock\n\
+ "lwsync # read_unlock\n\
1: lwarx %0,0,%1\n\
addic %0,%0,-1\n\
stwcx. %0,0,%1\n\
: "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;
-}
-
-static __inline__ int is_read_locked(rwlock_t *rw)
-{
- return rw->lock > 0;
-}
-
-static __inline__ int is_write_locked(rwlock_t *rw)
-{
- return rw->lock < 0;
-}
-
-#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
-#define spin_unlock_wait(x) do { cpu_relax(); } while(spin_is_locked(x))
-
-#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
-
-#define rwlock_is_locked(x) ((x)->lock)
+#endif /* CONFIG_SPINLINE */
#endif /* __KERNEL__ */
#endif /* __ASM_SPINLOCK_H */
git://git.onelab.eu / linux-2.6.git / blobdiff