Add cmpxchg_local to parisc

Use the new generic cmpxchg_local (disables interrupt). Also use the generic
cmpxchg as fallback if SMP is not set.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 33 insertions, 0 deletions

diff --git a/include/asm-parisc/atomic.h b/include/asm-parisc/atomic.h
index e894ee35074..57fcc4a5ebb 100644
--- a/include/asm-parisc/atomic.h
+++ b/include/asm-parisc/atomic.h
@@ -122,6 +122,39 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new_, int size)
                                     (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 unconsistent values.
  *