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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-cris/atomic.h
Linux-2.6.12-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-cris/atomic.h')
-rw-r--r--include/asm-cris/atomic.h150
1 files changed, 150 insertions, 0 deletions
diff --git a/include/asm-cris/atomic.h b/include/asm-cris/atomic.h
new file mode 100644
index 000000000000..b3dfea5a71e4
--- /dev/null
+++ b/include/asm-cris/atomic.h
@@ -0,0 +1,150 @@
+/* $Id: atomic.h,v 1.3 2001/07/25 16:15:19 bjornw Exp $ */
+
+#ifndef __ASM_CRIS_ATOMIC__
+#define __ASM_CRIS_ATOMIC__
+
+#include <asm/system.h>
+
+/*
+ * Atomic operations that C can't guarantee us. Useful for
+ * resource counting etc..
+ */
+
+/*
+ * Make sure gcc doesn't try to be clever and move things around
+ * on us. We need to use _exactly_ the address the user gave us,
+ * not some alias that contains the same information.
+ */
+
+#define __atomic_fool_gcc(x) (*(struct { int a[100]; } *)x)
+
+typedef struct { int counter; } atomic_t;
+
+#define ATOMIC_INIT(i) { (i) }
+
+#define atomic_read(v) ((v)->counter)
+#define atomic_set(v,i) (((v)->counter) = (i))
+
+/* These should be written in asm but we do it in C for now. */
+
+extern __inline__ void atomic_add(int i, volatile atomic_t *v)
+{
+ unsigned long flags;
+ local_save_flags(flags);
+ local_irq_disable();
+ v->counter += i;
+ local_irq_restore(flags);
+}
+
+extern __inline__ void atomic_sub(int i, volatile atomic_t *v)
+{
+ unsigned long flags;
+ local_save_flags(flags);
+ local_irq_disable();
+ v->counter -= i;
+ local_irq_restore(flags);
+}
+
+extern __inline__ int atomic_add_return(int i, volatile atomic_t *v)
+{
+ unsigned long flags;
+ int retval;
+ local_save_flags(flags);
+ local_irq_disable();
+ retval = (v->counter += i);
+ local_irq_restore(flags);
+ return retval;
+}
+
+#define atomic_add_negative(a, v) (atomic_add_return((a), (v)) < 0)
+
+extern __inline__ int atomic_sub_return(int i, volatile atomic_t *v)
+{
+ unsigned long flags;
+ int retval;
+ local_save_flags(flags);
+ local_irq_disable();
+ retval = (v->counter -= i);
+ local_irq_restore(flags);
+ return retval;
+}
+
+extern __inline__ int atomic_sub_and_test(int i, volatile atomic_t *v)
+{
+ int retval;
+ unsigned long flags;
+ local_save_flags(flags);
+ local_irq_disable();
+ retval = (v->counter -= i) == 0;
+ local_irq_restore(flags);
+ return retval;
+}
+
+extern __inline__ void atomic_inc(volatile atomic_t *v)
+{
+ unsigned long flags;
+ local_save_flags(flags);
+ local_irq_disable();
+ (v->counter)++;
+ local_irq_restore(flags);
+}
+
+extern __inline__ void atomic_dec(volatile atomic_t *v)
+{
+ unsigned long flags;
+ local_save_flags(flags);
+ local_irq_disable();
+ (v->counter)--;
+ local_irq_restore(flags);
+}
+
+extern __inline__ int atomic_inc_return(volatile atomic_t *v)
+{
+ unsigned long flags;
+ int retval;
+ local_save_flags(flags);
+ local_irq_disable();
+ retval = (v->counter)++;
+ local_irq_restore(flags);
+ return retval;
+}
+
+extern __inline__ int atomic_dec_return(volatile atomic_t *v)
+{
+ unsigned long flags;
+ int retval;
+ local_save_flags(flags);
+ local_irq_disable();
+ retval = (v->counter)--;
+ local_irq_restore(flags);
+ return retval;
+}
+extern __inline__ int atomic_dec_and_test(volatile atomic_t *v)
+{
+ int retval;
+ unsigned long flags;
+ local_save_flags(flags);
+ local_irq_disable();
+ retval = --(v->counter) == 0;
+ local_irq_restore(flags);
+ return retval;
+}
+
+extern __inline__ int atomic_inc_and_test(volatile atomic_t *v)
+{
+ int retval;
+ unsigned long flags;
+ local_save_flags(flags);
+ local_irq_disable();
+ retval = ++(v->counter) == 0;
+ local_irq_restore(flags);
+ return retval;
+}
+
+/* Atomic operations are already serializing */
+#define smp_mb__before_atomic_dec() barrier()
+#define smp_mb__after_atomic_dec() barrier()
+#define smp_mb__before_atomic_inc() barrier()
+#define smp_mb__after_atomic_inc() barrier()
+
+#endif