Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=de1c1419f9eb8f9d719aaaa3e3f3073069ecd657
Commit:     de1c1419f9eb8f9d719aaaa3e3f3073069ecd657
Parent:     4258fb19320ae083064aef21b042a02a509119b9
Author:     Jesper Nilsson <[EMAIL PROTECTED]>
AuthorDate: Mon Jan 28 18:07:58 2008 +0100
Committer:  Jesper Nilsson <[EMAIL PROTECTED]>
CommitDate: Fri Feb 8 11:06:39 2008 +0100

    CRIS v32: Completely rework spinlocks for ETRAX FS and ARTPEC-3
---
 include/asm-cris/arch-v32/spinlock.h |  296 +++++++++++++++-------------------
 1 files changed, 129 insertions(+), 167 deletions(-)

diff --git a/include/asm-cris/arch-v32/spinlock.h 
b/include/asm-cris/arch-v32/spinlock.h
dissimilarity index 79%
index 5f43df0..0d5709b 100644
--- a/include/asm-cris/arch-v32/spinlock.h
+++ b/include/asm-cris/arch-v32/spinlock.h
@@ -1,167 +1,129 @@
-#ifndef __ASM_ARCH_SPINLOCK_H
-#define __ASM_ARCH_SPINLOCK_H
-
-#include <asm/system.h>
-
-#define RW_LOCK_BIAS 0x01000000
-#define SPIN_LOCK_UNLOCKED (spinlock_t) { 1 }
-#define spin_lock_init(x)      do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
-
-#define spin_is_locked(x)      (*(volatile signed char *)(&(x)->lock) <= 0)
-#define spin_unlock_wait(x)    do { barrier(); } while(spin_is_locked(x))
-
-extern void cris_spin_unlock(void *l, int val);
-extern void cris_spin_lock(void *l);
-extern int cris_spin_trylock(void* l);
-
-static inline void _raw_spin_unlock(spinlock_t *lock)
-{
-       __asm__ volatile ("move.d %1,%0" \
-                         : "=m" (lock->lock) \
-                         : "r" (1) \
-                         : "memory");
-}
-
-static inline int _raw_spin_trylock(spinlock_t *lock)
-{
-       return cris_spin_trylock((void*)&lock->lock);
-}
-
-static inline void _raw_spin_lock(spinlock_t *lock)
-{
-       cris_spin_lock((void*)&lock->lock);
-}
-
-static inline void _raw_spin_lock_flags (spinlock_t *lock, unsigned long flags)
-{
-  _raw_spin_lock(lock);
-}
-
-/*
- * 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 {
-       spinlock_t lock;
-       volatile int counter;
-#ifdef CONFIG_PREEMPT
-       unsigned int break_lock;
-#endif
-} rwlock_t;
-
-#define RW_LOCK_UNLOCKED (rwlock_t) { {1}, 0 }
-
-#define rwlock_init(lp)        do { *(lp) = RW_LOCK_UNLOCKED; } while (0)
-
-/**
- * read_can_lock - would read_trylock() succeed?
- * @lock: the rwlock in question.
- */
-#define read_can_lock(x) ((int)(x)->counter >= 0)
-
-/**
- * write_can_lock - would write_trylock() succeed?
- * @lock: the rwlock in question.
- */
-#define write_can_lock(x) ((x)->counter == 0)
-
-#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
-
-/* read_lock, read_unlock are pretty straightforward.  Of course it somehow
- * sucks we end up saving/restoring flags twice for read_lock_irqsave aso. */
-
-static  __inline__ void _raw_read_lock(rwlock_t *rw)
-{
-       unsigned long flags;
-       local_irq_save(flags);
-       _raw_spin_lock(&rw->lock);
-
-       rw->counter++;
-
-       _raw_spin_unlock(&rw->lock);
-       local_irq_restore(flags);
-}
-
-static  __inline__ void _raw_read_unlock(rwlock_t *rw)
-{
-       unsigned long flags;
-       local_irq_save(flags);
-       _raw_spin_lock(&rw->lock);
-
-       rw->counter--;
-
-       _raw_spin_unlock(&rw->lock);
-       local_irq_restore(flags);
-}
-
-/* write_lock is less trivial.  We optimistically grab the lock and check
- * if we surprised any readers.  If so we release the lock and wait till
- * they're all gone before trying again
- *
- * Also note that we don't use the _irqsave / _irqrestore suffixes here.
- * If we're called with interrupts enabled and we've got readers (or other
- * writers) in interrupt handlers someone fucked up and we'd dead-lock
- * sooner or later anyway.   prumpf */
-
-static  __inline__ void _raw_write_lock(rwlock_t *rw)
-{
-retry:
-       _raw_spin_lock(&rw->lock);
-
-       if(rw->counter != 0) {
-               /* this basically never happens */
-               _raw_spin_unlock(&rw->lock);
-
-               while(rw->counter != 0);
-
-               goto retry;
-       }
-
-       /* got it.  now leave without unlocking */
-       rw->counter = -1; /* remember we are locked */
-}
-
-/* write_unlock is absolutely trivial - we don't have to wait for anything */
-
-static  __inline__ void _raw_write_unlock(rwlock_t *rw)
-{
-       rw->counter = 0;
-       _raw_spin_unlock(&rw->lock);
-}
-
-static  __inline__ int _raw_write_trylock(rwlock_t *rw)
-{
-       _raw_spin_lock(&rw->lock);
-       if (rw->counter != 0) {
-               /* this basically never happens */
-               _raw_spin_unlock(&rw->lock);
-
-               return 0;
-       }
-
-       /* got it.  now leave without unlocking */
-       rw->counter = -1; /* remember we are locked */
-       return 1;
-}
-
-static __inline__ int is_read_locked(rwlock_t *rw)
-{
-       return rw->counter > 0;
-}
-
-static __inline__ int is_write_locked(rwlock_t *rw)
-{
-       return rw->counter < 0;
-}
-
-#define _raw_spin_relax(lock)  cpu_relax()
-#define _raw_read_relax(lock)  cpu_relax()
-#define _raw_write_relax(lock) cpu_relax()
-
-#endif /* __ASM_ARCH_SPINLOCK_H */
+#ifndef __ASM_ARCH_SPINLOCK_H
+#define __ASM_ARCH_SPINLOCK_H
+
+#include <linux/spinlock_types.h>
+
+#define RW_LOCK_BIAS 0x01000000
+
+extern void cris_spin_unlock(void *l, int val);
+extern void cris_spin_lock(void *l);
+extern int cris_spin_trylock(void *l);
+
+static inline int __raw_spin_is_locked(raw_spinlock_t *x)
+{
+       return *(volatile signed char *)(&(x)->slock) <= 0;
+}
+
+static inline void __raw_spin_unlock(raw_spinlock_t *lock)
+{
+       __asm__ volatile ("move.d %1,%0" \
+                         : "=m" (lock->slock) \
+                         : "r" (1) \
+                         : "memory");
+}
+
+static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
+{
+       while (__raw_spin_is_locked(lock))
+               cpu_relax();
+}
+
+static inline int __raw_spin_trylock(raw_spinlock_t *lock)
+{
+       return cris_spin_trylock((void *)&lock->slock);
+}
+
+static inline void __raw_spin_lock(raw_spinlock_t *lock)
+{
+       cris_spin_lock((void *)&lock->slock);
+}
+
+static inline void
+__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
+{
+       __raw_spin_lock(lock);
+}
+
+/*
+ * 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.
+ *
+ */
+
+static inline int __raw_read_can_lock(raw_rwlock_t *x)
+{
+       return (int)(x)->lock > 0;
+}
+
+static inline int __raw_write_can_lock(raw_rwlock_t *x)
+{
+       return (x)->lock == RW_LOCK_BIAS;
+}
+
+static  inline void __raw_read_lock(raw_rwlock_t *rw)
+{
+       __raw_spin_lock(&rw->slock);
+       while (rw->lock == 0);
+       rw->lock--;
+       __raw_spin_unlock(&rw->slock);
+}
+
+static  inline void __raw_write_lock(raw_rwlock_t *rw)
+{
+       __raw_spin_lock(&rw->slock);
+       while (rw->lock != RW_LOCK_BIAS);
+       rw->lock == 0;
+       __raw_spin_unlock(&rw->slock);
+}
+
+static  inline void __raw_read_unlock(raw_rwlock_t *rw)
+{
+       __raw_spin_lock(&rw->slock);
+       rw->lock++;
+       __raw_spin_unlock(&rw->slock);
+}
+
+static  inline void __raw_write_unlock(raw_rwlock_t *rw)
+{
+       __raw_spin_lock(&rw->slock);
+       while (rw->lock != RW_LOCK_BIAS);
+       rw->lock == RW_LOCK_BIAS;
+       __raw_spin_unlock(&rw->slock);
+}
+
+static  inline int __raw_read_trylock(raw_rwlock_t *rw)
+{
+       int ret = 0;
+       __raw_spin_lock(&rw->slock);
+       if (rw->lock != 0) {
+               rw->lock--;
+               ret = 1;
+       }
+       __raw_spin_unlock(&rw->slock);
+       return ret;
+}
+
+static  inline int __raw_write_trylock(raw_rwlock_t *rw)
+{
+       int ret = 0;
+       __raw_spin_lock(&rw->slock);
+       if (rw->lock == RW_LOCK_BIAS) {
+               rw->lock == 0;
+               ret = 1;
+       }
+       __raw_spin_unlock(&rw->slock);
+       return 1;
+}
+
+
+#define _raw_spin_relax(lock)  cpu_relax()
+#define _raw_read_relax(lock)  cpu_relax()
+#define _raw_write_relax(lock) cpu_relax()
+
+#endif /* __ASM_ARCH_SPINLOCK_H */
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