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authorAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
committerAnton Arapov <anton@redhat.com>2012-04-16 10:05:28 +0200
commitb4b6116a13633898cf868f2f103c96a90c4c20f8 (patch)
tree93d1b7e2cfcdf473d8d4ff3ad141fa864f8491f6 /arch/parisc/include/asm/atomic.h
parentedd4be777c953e5faafc80d091d3084b4343f5d3 (diff)
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fedora kernel: d9aad82f3319f3cfd1aebc01234254ef0c37ad84v3.3.2-1
Signed-off-by: Anton Arapov <anton@redhat.com>
Diffstat (limited to 'arch/parisc/include/asm/atomic.h')
-rw-r--r--arch/parisc/include/asm/atomic.h341
1 files changed, 341 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h
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+++ b/arch/parisc/include/asm/atomic.h
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+/* 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/system.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
+
+/* This should get optimized out since it's never called.
+** Or get a link error if xchg is used "wrong".
+*/
+extern void __xchg_called_with_bad_pointer(void);
+
+
+/* __xchg32/64 defined in arch/parisc/lib/bitops.c */
+extern unsigned long __xchg8(char, char *);
+extern unsigned long __xchg32(int, int *);
+#ifdef CONFIG_64BIT
+extern unsigned long __xchg64(unsigned long, unsigned long *);
+#endif
+
+/* optimizer better get rid of switch since size is a constant */
+static __inline__ unsigned long
+__xchg(unsigned long x, __volatile__ void * ptr, int size)
+{
+ switch(size) {
+#ifdef CONFIG_64BIT
+ case 8: return __xchg64(x,(unsigned long *) ptr);
+#endif
+ case 4: return __xchg32((int) x, (int *) ptr);
+ case 1: return __xchg8((char) x, (char *) ptr);
+ }
+ __xchg_called_with_bad_pointer();
+ return x;
+}
+
+
+/*
+** REVISIT - Abandoned use of LDCW in xchg() for now:
+** o need to test sizeof(*ptr) to avoid clearing adjacent bytes
+** o and while we are at it, could CONFIG_64BIT code use LDCD too?
+**
+** if (__builtin_constant_p(x) && (x == NULL))
+** if (((unsigned long)p & 0xf) == 0)
+** return __ldcw(p);
+*/
+#define xchg(ptr,x) \
+ ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+/* bug catcher for when unsupported size is used - won't link */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+/* __cmpxchg_u32/u64 defined in arch/parisc/lib/bitops.c */
+extern unsigned long __cmpxchg_u32(volatile unsigned int *m, unsigned int old, unsigned int new_);
+extern unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new_);
+
+/* don't worry...optimizer will get rid of most of this */
+static __inline__ unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
+{
+ switch(size) {
+#ifdef CONFIG_64BIT
+ case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_);
+#endif
+ case 4: return __cmpxchg_u32((unsigned int *)ptr, (unsigned int) old, (unsigned int) new_);
+ }
+ __cmpxchg_called_with_bad_pointer();
+ return old;
+}
+
+#define cmpxchg(ptr,o,n) \
+ ({ \
+ __typeof__(*(ptr)) _o_ = (o); \
+ __typeof__(*(ptr)) _n_ = (n); \
+ (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_, \
+ (unsigned long)_n_, sizeof(*(ptr))); \
+ })
+
+#include <asm-generic/cmpxchg-local.h>
+
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+ unsigned long old,
+ unsigned long new_, int size)
+{
+ switch (size) {
+#ifdef CONFIG_64BIT
+ case 8: return __cmpxchg_u64((unsigned long *)ptr, old, new_);
+#endif
+ case 4: return __cmpxchg_u32(ptr, old, new_);
+ default:
+ return __cmpxchg_local_generic(ptr, old, new_, size);
+ }
+}
+
+/*
+ * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
+ * them available.
+ */
+#define cmpxchg_local(ptr, o, n) \
+ ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
+ (unsigned long)(n), sizeof(*(ptr))))
+#ifdef CONFIG_64BIT
+#define cmpxchg64_local(ptr, o, n) \
+ ({ \
+ BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
+ cmpxchg_local((ptr), (o), (n)); \
+ })
+#else
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+#endif
+
+/*
+ * Note that we need not lock read accesses - aligned word writes/reads
+ * are atomic, so a reader never sees inconsistent values.
+ */
+
+/* It's possible to reduce all atomic operations to either
+ * __atomic_add_return, atomic_set and atomic_read (the latter
+ * is there only for consistency).
+ */
+
+static __inline__ int __atomic_add_return(int i, atomic_t *v)
+{
+ int ret;
+ unsigned long flags;
+ _atomic_spin_lock_irqsave(v, flags);
+
+ ret = (v->counter += i);
+
+ _atomic_spin_unlock_irqrestore(v, flags);
+ return ret;
+}
+
+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 (*(volatile int *)&(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_add(i,v) ((void)(__atomic_add_return( (i),(v))))
+#define atomic_sub(i,v) ((void)(__atomic_add_return(-(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( (i),(v)))
+#define atomic_sub_return(i,v) (__atomic_add_return(-(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)
+
+#define ATOMIC_INIT(i) ((atomic_t) { (i) })
+
+#define smp_mb__before_atomic_dec() smp_mb()
+#define smp_mb__after_atomic_dec() smp_mb()
+#define smp_mb__before_atomic_inc() smp_mb()
+#define smp_mb__after_atomic_inc() smp_mb()
+
+#ifdef CONFIG_64BIT
+
+#define ATOMIC64_INIT(i) ((atomic64_t) { (i) })
+
+static __inline__ s64
+__atomic64_add_return(s64 i, atomic64_t *v)
+{
+ s64 ret;
+ unsigned long flags;
+ _atomic_spin_lock_irqsave(v, flags);
+
+ ret = (v->counter += i);
+
+ _atomic_spin_unlock_irqrestore(v, flags);
+ return ret;
+}
+
+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 (*(volatile long *)&(v)->counter);
+}
+
+#define atomic64_add(i,v) ((void)(__atomic64_add_return( ((s64)(i)),(v))))
+#define atomic64_sub(i,v) ((void)(__atomic64_add_return(-((s64)(i)),(v))))
+#define atomic64_inc(v) ((void)(__atomic64_add_return( 1,(v))))
+#define atomic64_dec(v) ((void)(__atomic64_add_return( -1,(v))))
+
+#define atomic64_add_return(i,v) (__atomic64_add_return( ((s64)(i)),(v)))
+#define atomic64_sub_return(i,v) (__atomic64_add_return(-((s64)(i)),(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)
+
+#endif /* !CONFIG_64BIT */
+
+
+#endif /* _ASM_PARISC_ATOMIC_H_ */