[PATCH 07/10] atomic.h : Add atomic64 cmpxchg, xchg and add_unless to powerpc

From: Mathieu Desnoyers
Date: Sun Feb 11 2007 - 14:28:51 EST


atomic.h : Add atomic64 cmpxchg, xchg and add_unless to powerpc

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxx>

--- a/include/asm-powerpc/atomic.h
+++ b/include/asm-powerpc/atomic.h
@@ -165,7 +165,7 @@ static __inline__ int atomic_dec_return(atomic_t *v)
return t;
}

-#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
+#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))

/**
@@ -413,6 +413,42 @@ static __inline__ long atomic64_dec_if_positive(atomic64_t *v)
return t;
}

+#define atomic64_cmpxchg(v, o, n) (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 non-zero if @v was not @u, and zero otherwise.
+ */
+static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
+{
+ long t;
+
+ __asm__ __volatile__ (
+ LWSYNC_ON_SMP
+"1: ldarx %0,0,%1 # atomic_add_unless\n\
+ cmpd 0,%0,%3 \n\
+ beq- 2f \n\
+ add %0,%2,%0 \n"
+" stdcx. %0,0,%1 \n\
+ bne- 1b \n"
+ ISYNC_ON_SMP
+" subf %0,%2,%0 \n\
+2:"
+ : "=&r" (t)
+ : "r" (&v->counter), "r" (a), "r" (u)
+ : "cc", "memory");
+
+ return t != u;
+}
+
+#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
+
#endif /* __powerpc64__ */

#include <asm-generic/atomic.h>
--- a/include/asm-powerpc/bitops.h
+++ b/include/asm-powerpc/bitops.h
@@ -39,7 +39,6 @@
#ifdef __KERNEL__

#include <linux/compiler.h>
-#include <asm/atomic.h>
#include <asm/asm-compat.h>
#include <asm/synch.h>

--- a/include/asm-powerpc/system.h
+++ b/include/asm-powerpc/system.h
@@ -7,7 +7,6 @@
#include <linux/kernel.h>

#include <asm/hw_irq.h>
-#include <asm/atomic.h>

/*
* Memory barrier.
@@ -226,6 +225,29 @@ __xchg_u32(volatile void *p, unsigned long val)
return prev;
}

+/*
+ * Atomic exchange
+ *
+ * Changes the memory location '*ptr' to be val and returns
+ * the previous value stored there.
+ */
+static __inline__ unsigned long
+__xchg_u32_local(volatile void *p, unsigned long val)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__(
+"1: lwarx %0,0,%2 \n"
+ PPC405_ERR77(0,%2)
+" stwcx. %3,0,%2 \n\
+ bne- 1b"
+ : "=&r" (prev), "+m" (*(volatile unsigned int *)p)
+ : "r" (p), "r" (val)
+ : "cc", "memory");
+
+ return prev;
+}
+
#ifdef CONFIG_PPC64
static __inline__ unsigned long
__xchg_u64(volatile void *p, unsigned long val)
@@ -245,6 +267,23 @@ __xchg_u64(volatile void *p, unsigned long val)

return prev;
}
+
+static __inline__ unsigned long
+__xchg_u64_local(volatile void *p, unsigned long val)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__(
+"1: ldarx %0,0,%2 \n"
+ PPC405_ERR77(0,%2)
+" stdcx. %3,0,%2 \n\
+ bne- 1b"
+ : "=&r" (prev), "+m" (*(volatile unsigned long *)p)
+ : "r" (p), "r" (val)
+ : "cc", "memory");
+
+ return prev;
+}
#endif

/*
@@ -268,12 +307,33 @@ __xchg(volatile void *ptr, unsigned long x, unsigned int size)
return x;
}

+static __inline__ unsigned long
+__xchg_local(volatile void *ptr, unsigned long x, unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __xchg_u32_local(ptr, x);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __xchg_u64_local(ptr, x);
+#endif
+ }
+ __xchg_called_with_bad_pointer();
+ return x;
+}
#define xchg(ptr,x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \
})

+#define xchg_local(ptr,x) \
+ ({ \
+ __typeof__(*(ptr)) _x_ = (x); \
+ (__typeof__(*(ptr))) __xchg_local((ptr), \
+ (unsigned long)_x_, sizeof(*(ptr))); \
+ })
+
#define tas(ptr) (xchg((ptr),1))

/*
@@ -305,6 +365,28 @@ __cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
return prev;
}

+static __inline__ unsigned long
+__cmpxchg_u32_local(volatile unsigned int *p, unsigned long old,
+ unsigned long new)
+{
+ unsigned int prev;
+
+ __asm__ __volatile__ (
+"1: lwarx %0,0,%2 # __cmpxchg_u32\n\
+ cmpw 0,%0,%3\n\
+ bne- 2f\n"
+ PPC405_ERR77(0,%2)
+" stwcx. %4,0,%2\n\
+ bne- 1b"
+ "\n\
+2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
+
#ifdef CONFIG_PPC64
static __inline__ unsigned long
__cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
@@ -327,6 +409,27 @@ __cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)

return prev;
}
+
+static __inline__ unsigned long
+__cmpxchg_u64_local(volatile unsigned long *p, unsigned long old,
+ unsigned long new)
+{
+ unsigned long prev;
+
+ __asm__ __volatile__ (
+"1: ldarx %0,0,%2 # __cmpxchg_u64\n\
+ cmpd 0,%0,%3\n\
+ bne- 2f\n\
+ stdcx. %4,0,%2\n\
+ bne- 1b"
+ "\n\
+2:"
+ : "=&r" (prev), "+m" (*p)
+ : "r" (p), "r" (old), "r" (new)
+ : "cc", "memory");
+
+ return prev;
+}
#endif

/* This function doesn't exist, so you'll get a linker error
@@ -349,6 +452,22 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
return old;
}

+static __inline__ unsigned long
+__cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new,
+ unsigned int size)
+{
+ switch (size) {
+ case 4:
+ return __cmpxchg_u32_local(ptr, old, new);
+#ifdef CONFIG_PPC64
+ case 8:
+ return __cmpxchg_u64_local(ptr, old, new);
+#endif
+ }
+ __cmpxchg_called_with_bad_pointer();
+ return old;
+}
+
#define cmpxchg(ptr,o,n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
@@ -357,6 +476,15 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
(unsigned long)_n_, sizeof(*(ptr))); \
})

+
+#define cmpxchg_local(ptr,o,n) \
+ ({ \
+ __typeof__(*(ptr)) _o_ = (o); \
+ __typeof__(*(ptr)) _n_ = (n); \
+ (__typeof__(*(ptr))) __cmpxchg_local((ptr), (unsigned long)_o_, \
+ (unsigned long)_n_, sizeof(*(ptr))); \
+ })
+
#ifdef CONFIG_PPC64
/*
* We handle most unaligned accesses in hardware. On the other hand
-
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