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

[akpm@linux-foundation.org: build fixes]
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 129 insertions, 1 deletions

diff --git a/include/asm-powerpc/system.h b/include/asm-powerpc/system.h
index d3e0906ff2bc..77bf5873a013 100644
--- 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.
@@ -227,6 +226,29 @@ __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)
@@ -246,6 +268,23 @@ __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
 
 /*
@@ -269,12 +308,33 @@ __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))
 
 /*
@@ -306,6 +366,28 @@ __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)
@@ -328,6 +410,27 @@ __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
@@ -350,6 +453,22 @@ __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);                                       \
@@ -358,6 +477,15 @@ __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