--- /dev/null
+/* Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
+ * Copyright (C) 2006 Kyle McMartin <kyle@parisc-linux.org>
+ */
+
+#ifndef _ASM_PARISC_ATOMIC_H_
+#define _ASM_PARISC_ATOMIC_H_
+
+#include <linux/types.h>
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+/*
+ * Atomic operations that C can't guarantee us. Useful for
+ * resource counting etc..
+ *
+ * And probably incredibly slow on parisc. OTOH, we don't
+ * have to write any serious assembly. prumpf
+ */
+
+#ifdef CONFIG_SMP
+#include <asm/spinlock.h>
+#include <asm/cache.h> /* we use L1_CACHE_BYTES */
+
+/* Use an array of spinlocks for our atomic_ts.
+ * Hash function to index into a different SPINLOCK.
+ * Since "a" is usually an address, use one spinlock per cacheline.
+ */
+# define ATOMIC_HASH_SIZE 4
+# define ATOMIC_HASH(a) (&(__atomic_hash[ (((unsigned long) (a))/L1_CACHE_BYTES) & (ATOMIC_HASH_SIZE-1) ]))
+
+extern arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned;
+
+/* Can't use raw_spin_lock_irq because of #include problems, so
+ * this is the substitute */
+#define _atomic_spin_lock_irqsave(l,f) do { \
+ arch_spinlock_t *s = ATOMIC_HASH(l); \
+ local_irq_save(f); \
+ arch_spin_lock(s); \
+} while(0)
+
+#define _atomic_spin_unlock_irqrestore(l,f) do { \
+ arch_spinlock_t *s = ATOMIC_HASH(l); \
+ arch_spin_unlock(s); \
+ local_irq_restore(f); \
+} while(0)
+
+
+#else
+# define _atomic_spin_lock_irqsave(l,f) do { local_irq_save(f); } while (0)
+# define _atomic_spin_unlock_irqrestore(l,f) do { local_irq_restore(f); } while (0)
+#endif
+
+/*
+ * Note that we need not lock read accesses - aligned word writes/reads
+ * are atomic, so a reader never sees inconsistent values.
+ */
+
+static __inline__ void atomic_set(atomic_t *v, int i)
+{
+ unsigned long flags;
+ _atomic_spin_lock_irqsave(v, flags);
+
+ v->counter = i;
+
+ _atomic_spin_unlock_irqrestore(v, flags);
+}
+
+static __inline__ int atomic_read(const atomic_t *v)
+{
+ return ACCESS_ONCE((v)->counter);
+}
+
+/* exported interface */
+#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+/**
+ * __atomic_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns the old value of @v.
+ */
+static __inline__ int __atomic_add_unless(atomic_t *v, int a, int u)
+{
+ int c, old;
+ c = atomic_read(v);
+ for (;;) {
+ if (unlikely(c == (u)))
+ break;
+ old = atomic_cmpxchg((v), c, c + (a));
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+ return c;
+}
+
+#define ATOMIC_OP(op, c_op) \
+static __inline__ void atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ \
+ _atomic_spin_lock_irqsave(v, flags); \
+ v->counter c_op i; \
+ _atomic_spin_unlock_irqrestore(v, flags); \
+} \
+
+#define ATOMIC_OP_RETURN(op, c_op) \
+static __inline__ int atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ unsigned long flags; \
+ int ret; \
+ \
+ _atomic_spin_lock_irqsave(v, flags); \
+ ret = (v->counter c_op i); \
+ _atomic_spin_unlock_irqrestore(v, flags); \
+ \
+ return ret; \
+}
+
+#define ATOMIC_OPS(op, c_op) ATOMIC_OP(op, c_op) ATOMIC_OP_RETURN(op, c_op)
+
+ATOMIC_OPS(add, +=)
+ATOMIC_OPS(sub, -=)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define atomic_inc(v) (atomic_add( 1,(v)))
+#define atomic_dec(v) (atomic_add( -1,(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)
+
+#define ATOMIC_INIT(i) { (i) }
+
+#ifdef CONFIG_64BIT
+
+#define ATOMIC64_INIT(i) { (i) }
+
+#define ATOMIC64_OP(op, c_op) \
+static __inline__ void atomic64_##op(s64 i, atomic64_t *v) \
+{ \
+ unsigned long flags; \
+ \
+ _atomic_spin_lock_irqsave(v, flags); \
+ v->counter c_op i; \
+ _atomic_spin_unlock_irqrestore(v, flags); \
+} \
+
+#define ATOMIC64_OP_RETURN(op, c_op) \
+static __inline__ s64 atomic64_##op##_return(s64 i, atomic64_t *v) \
+{ \
+ unsigned long flags; \
+ s64 ret; \
+ \
+ _atomic_spin_lock_irqsave(v, flags); \
+ ret = (v->counter c_op i); \
+ _atomic_spin_unlock_irqrestore(v, flags); \
+ \
+ return ret; \
+}
+
+#define ATOMIC64_OPS(op, c_op) ATOMIC64_OP(op, c_op) ATOMIC64_OP_RETURN(op, c_op)
+
+ATOMIC64_OPS(add, +=)
+ATOMIC64_OPS(sub, -=)
+
+#undef ATOMIC64_OPS
+#undef ATOMIC64_OP_RETURN
+#undef ATOMIC64_OP
+
+static __inline__ void
+atomic64_set(atomic64_t *v, s64 i)
+{
+ unsigned long flags;
+ _atomic_spin_lock_irqsave(v, flags);
+
+ v->counter = i;
+
+ _atomic_spin_unlock_irqrestore(v, flags);
+}
+
+static __inline__ s64
+atomic64_read(const atomic64_t *v)
+{
+ return ACCESS_ONCE((v)->counter);
+}
+
+#define atomic64_inc(v) (atomic64_add( 1,(v)))
+#define atomic64_dec(v) (atomic64_add( -1,(v)))
+
+#define atomic64_inc_return(v) (atomic64_add_return( 1,(v)))
+#define atomic64_dec_return(v) (atomic64_add_return( -1,(v)))
+
+#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
+
+#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
+#define atomic64_dec_and_test(v) (atomic64_dec_return(v) == 0)
+#define atomic64_sub_and_test(i,v) (atomic64_sub_return((i),(v)) == 0)
+
+/* exported interface */
+#define atomic64_cmpxchg(v, o, n) \
+ ((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
+#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
+
+/**
+ * atomic64_add_unless - add unless the number is a given value
+ * @v: pointer of type atomic64_t
+ * @a: the amount to add to v...
+ * @u: ...unless v is equal to u.
+ *
+ * Atomically adds @a to @v, so long as it was not @u.
+ * Returns the old value of @v.
+ */
+static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
+{
+ long c, old;
+ c = atomic64_read(v);
+ for (;;) {
+ if (unlikely(c == (u)))
+ break;
+ old = atomic64_cmpxchg((v), c, c + (a));
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+ return c != (u);
+}
+
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+
+/*
+ * atomic64_dec_if_positive - decrement by 1 if old value positive
+ * @v: pointer of type atomic_t
+ *
+ * The function returns the old value of *v minus 1, even if
+ * the atomic variable, v, was not decremented.
+ */
+static inline long atomic64_dec_if_positive(atomic64_t *v)
+{
+ long c, old, dec;
+ c = atomic64_read(v);
+ for (;;) {
+ dec = c - 1;
+ if (unlikely(dec < 0))
+ break;
+ old = atomic64_cmpxchg((v), c, dec);
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+ return dec;
+}
+
+#endif /* !CONFIG_64BIT */
+
+
+#endif /* _ASM_PARISC_ATOMIC_H_ */
Code Review / kvmfornfv.git / blobdiff