1 files changed, 158 insertions, 0 deletions
diff --git a/include/asm-sparc/atomic.h b/include/asm-sparc/atomic.h
new file mode 100644
index 00000000000..37f6ab601c3
--- /dev/null
+++ b/include/asm-sparc/atomic.h
@@ -0,0 +1,158 @@
+/* atomic.h: These still suck, but the I-cache hit rate is higher.
+ *
+ * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
+ * Copyright (C) 2000 Anton Blanchard (anton@linuxcare.com.au)
+ *
+ * Additions by Keith M Wesolowski (wesolows@foobazco.org) based
+ * on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>.
+ */
+
+#ifndef __ARCH_SPARC_ATOMIC__
+#define __ARCH_SPARC_ATOMIC__
+
+#include <linux/config.h>
+
+typedef struct { volatile int counter; } atomic_t;
+
+#ifdef __KERNEL__
+
+#define ATOMIC_INIT(i)  { (i) }
+
+extern int __atomic_add_return(int, atomic_t *);
+extern void atomic_set(atomic_t *, int);
+
+#define atomic_read(v)          ((v)->counter)
+
+#define atomic_add(i, v)	((void)__atomic_add_return( (int)(i), (v)))
+#define atomic_sub(i, v)	((void)__atomic_add_return(-(int)(i), (v)))
+#define atomic_inc(v)		((void)__atomic_add_return(        1, (v)))
+#define atomic_dec(v)		((void)__atomic_add_return(       -1, (v)))
+
+#define atomic_add_return(i, v)	(__atomic_add_return( (int)(i), (v)))
+#define atomic_sub_return(i, v)	(__atomic_add_return(-(int)(i), (v)))
+#define atomic_inc_return(v)	(__atomic_add_return(        1, (v)))
+#define atomic_dec_return(v)	(__atomic_add_return(       -1, (v)))
+
+#define atomic_add_negative(a, v)	(atomic_add_return((a), (v)) < 0)
+
+/*
+ * atomic_inc_and_test - increment and test
+ * @v: pointer of type atomic_t
+ *
+ * Atomically increments @v by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
+
+#define atomic_dec_and_test(v) (atomic_dec_return(v) == 0)
+#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
+
+/* This is the old 24-bit implementation.  It's still used internally
+ * by some sparc-specific code, notably the semaphore implementation.
+ */
+typedef struct { volatile int counter; } atomic24_t;
+
+#ifndef CONFIG_SMP
+
+#define ATOMIC24_INIT(i)  { (i) }
+#define atomic24_read(v)          ((v)->counter)
+#define atomic24_set(v, i)        (((v)->counter) = i)
+
+#else
+/* We do the bulk of the actual work out of line in two common
+ * routines in assembler, see arch/sparc/lib/atomic.S for the
+ * "fun" details.
+ *
+ * For SMP the trick is you embed the spin lock byte within
+ * the word, use the low byte so signedness is easily retained
+ * via a quick arithmetic shift.  It looks like this:
+ *
+ *	----------------------------------------
+ *	| signed 24-bit counter value |  lock  |  atomic_t
+ *	----------------------------------------
+ *	 31                          8 7      0
+ */
+
+#define ATOMIC24_INIT(i)	{ ((i) << 8) }
+
+static inline int atomic24_read(const atomic24_t *v)
+{
+	int ret = v->counter;
+
+	while(ret & 0xff)
+		ret = v->counter;
+
+	return ret >> 8;
+}
+
+#define atomic24_set(v, i)	(((v)->counter) = ((i) << 8))
+#endif
+
+static inline int __atomic24_add(int i, atomic24_t *v)
+{
+	register volatile int *ptr asm("g1");
+	register int increment asm("g2");
+	register int tmp1 asm("g3");
+	register int tmp2 asm("g4");
+	register int tmp3 asm("g7");
+
+	ptr = &v->counter;
+	increment = i;
+
+	__asm__ __volatile__(
+	"mov	%%o7, %%g4\n\t"
+	"call	___atomic24_add\n\t"
+	" add	%%o7, 8, %%o7\n"
+	: "=&r" (increment), "=r" (tmp1), "=r" (tmp2), "=r" (tmp3)
+	: "0" (increment), "r" (ptr)
+	: "memory", "cc");
+
+	return increment;
+}
+
+static inline int __atomic24_sub(int i, atomic24_t *v)
+{
+	register volatile int *ptr asm("g1");
+	register int increment asm("g2");
+	register int tmp1 asm("g3");
+	register int tmp2 asm("g4");
+	register int tmp3 asm("g7");
+
+	ptr = &v->counter;
+	increment = i;
+
+	__asm__ __volatile__(
+	"mov	%%o7, %%g4\n\t"
+	"call	___atomic24_sub\n\t"
+	" add	%%o7, 8, %%o7\n"
+	: "=&r" (increment), "=r" (tmp1), "=r" (tmp2), "=r" (tmp3)
+	: "0" (increment), "r" (ptr)
+	: "memory", "cc");
+
+	return increment;
+}
+
+#define atomic24_add(i, v) ((void)__atomic24_add((i), (v)))
+#define atomic24_sub(i, v) ((void)__atomic24_sub((i), (v)))
+
+#define atomic24_dec_return(v) __atomic24_sub(1, (v))
+#define atomic24_inc_return(v) __atomic24_add(1, (v))
+
+#define atomic24_sub_and_test(i, v) (__atomic24_sub((i), (v)) == 0)
+#define atomic24_dec_and_test(v) (__atomic24_sub(1, (v)) == 0)
+
+#define atomic24_inc(v) ((void)__atomic24_add(1, (v)))
+#define atomic24_dec(v) ((void)__atomic24_sub(1, (v)))
+
+#define atomic24_add_negative(i, v) (__atomic24_add((i), (v)) < 0)
+
+/* 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 /* !(__KERNEL__) */
+
+#endif /* !(__ARCH_SPARC_ATOMIC__) */