Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / arch / powerpc / include / asm / cmpxchg.h
diff --git a/kernel/arch/powerpc/include/asm/cmpxchg.h b/kernel/arch/powerpc/include/asm/cmpxchg.h
new file mode 100644 (file)
index 0000000..d463c68
--- /dev/null
@@ -0,0 +1,310 @@
+#ifndef _ASM_POWERPC_CMPXCHG_H_
+#define _ASM_POWERPC_CMPXCHG_H_
+
+#ifdef __KERNEL__
+#include <linux/compiler.h>
+#include <asm/synch.h>
+#include <asm/asm-compat.h>
+
+/*
+ * Atomic exchange
+ *
+ * Changes the memory location '*ptr' to be val and returns
+ * the previous value stored there.
+ */
+static __always_inline unsigned long
+__xchg_u32(volatile void *p, unsigned long val)
+{
+       unsigned long prev;
+
+       __asm__ __volatile__(
+       PPC_RELEASE_BARRIER
+"1:    lwarx   %0,0,%2 \n"
+       PPC405_ERR77(0,%2)
+"      stwcx.  %3,0,%2 \n\
+       bne-    1b"
+       PPC_ACQUIRE_BARRIER
+       : "=&r" (prev), "+m" (*(volatile unsigned int *)p)
+       : "r" (p), "r" (val)
+       : "cc", "memory");
+
+       return prev;
+}
+
+/*
+ * Atomic exchange
+ *
+ * Changes the memory location '*ptr' to be val and returns
+ * the previous value stored there.
+ */
+static __always_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 __always_inline unsigned long
+__xchg_u64(volatile void *p, unsigned long val)
+{
+       unsigned long prev;
+
+       __asm__ __volatile__(
+       PPC_RELEASE_BARRIER
+"1:    ldarx   %0,0,%2 \n"
+       PPC405_ERR77(0,%2)
+"      stdcx.  %3,0,%2 \n\
+       bne-    1b"
+       PPC_ACQUIRE_BARRIER
+       : "=&r" (prev), "+m" (*(volatile unsigned long *)p)
+       : "r" (p), "r" (val)
+       : "cc", "memory");
+
+       return prev;
+}
+
+static __always_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
+
+/*
+ * This function doesn't exist, so you'll get a linker error
+ * if something tries to do an invalid xchg().
+ */
+extern void __xchg_called_with_bad_pointer(void);
+
+static __always_inline unsigned long
+__xchg(volatile void *ptr, unsigned long x, unsigned int size)
+{
+       switch (size) {
+       case 4:
+               return __xchg_u32(ptr, x);
+#ifdef CONFIG_PPC64
+       case 8:
+               return __xchg_u64(ptr, x);
+#endif
+       }
+       __xchg_called_with_bad_pointer();
+       return x;
+}
+
+static __always_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)));                         \
+  })
+
+/*
+ * Compare and exchange - if *p == old, set it to new,
+ * and return the old value of *p.
+ */
+#define __HAVE_ARCH_CMPXCHG    1
+
+static __always_inline unsigned long
+__cmpxchg_u32(volatile unsigned int *p, unsigned long old, unsigned long new)
+{
+       unsigned int prev;
+
+       __asm__ __volatile__ (
+       PPC_RELEASE_BARRIER
+"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"
+       PPC_ACQUIRE_BARRIER
+       "\n\
+2:"
+       : "=&r" (prev), "+m" (*p)
+       : "r" (p), "r" (old), "r" (new)
+       : "cc", "memory");
+
+       return prev;
+}
+
+static __always_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 __always_inline unsigned long
+__cmpxchg_u64(volatile unsigned long *p, unsigned long old, unsigned long new)
+{
+       unsigned long prev;
+
+       __asm__ __volatile__ (
+       PPC_RELEASE_BARRIER
+"1:    ldarx   %0,0,%2         # __cmpxchg_u64\n\
+       cmpd    0,%0,%3\n\
+       bne-    2f\n\
+       stdcx.  %4,0,%2\n\
+       bne-    1b"
+       PPC_ACQUIRE_BARRIER
+       "\n\
+2:"
+       : "=&r" (prev), "+m" (*p)
+       : "r" (p), "r" (old), "r" (new)
+       : "cc", "memory");
+
+       return prev;
+}
+
+static __always_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
+   if something tries to do an invalid cmpxchg().  */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+static __always_inline unsigned long
+__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new,
+         unsigned int size)
+{
+       switch (size) {
+       case 4:
+               return __cmpxchg_u32(ptr, old, new);
+#ifdef CONFIG_PPC64
+       case 8:
+               return __cmpxchg_u64(ptr, old, new);
+#endif
+       }
+       __cmpxchg_called_with_bad_pointer();
+       return old;
+}
+
+static __always_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);                                      \
+     __typeof__(*(ptr)) _n_ = (n);                                      \
+     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,          \
+                                   (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
+#define cmpxchg64(ptr, o, n)                                           \
+  ({                                                                   \
+       BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
+       cmpxchg((ptr), (o), (n));                                       \
+  })
+#define cmpxchg64_local(ptr, o, n)                                     \
+  ({                                                                   \
+       BUILD_BUG_ON(sizeof(*(ptr)) != 8);                              \
+       cmpxchg_local((ptr), (o), (n));                                 \
+  })
+#define cmpxchg64_relaxed      cmpxchg64_local
+#else
+#include <asm-generic/cmpxchg-local.h>
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+#endif
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_CMPXCHG_H_ */