local_t: i386 extension

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 58 insertions, 1 deletions

diff --git a/include/asm-i386/system.h b/include/asm-i386/system.h
index c3a58c08c495..e0454afb950f 100644
--- a/include/asm-i386/system.h
+++ b/include/asm-i386/system.h
@@ -305,6 +305,9 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
 #define sync_cmpxchg(ptr,o,n)\
         ((__typeof__(*(ptr)))__sync_cmpxchg((ptr),(unsigned long)(o),\
                                         (unsigned long)(n),sizeof(*(ptr))))
+#define cmpxchg_local(ptr,o,n)\
+        ((__typeof__(*(ptr)))__cmpxchg_local((ptr),(unsigned long)(o),\
+                                        (unsigned long)(n),sizeof(*(ptr))))
 #endif
 
 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
@@ -367,6 +370,33 @@ static inline unsigned long __sync_cmpxchg(volatile void *ptr,
         return old;
 }
 
+static inline unsigned long __cmpxchg_local(volatile void *ptr,
+                        unsigned long old, unsigned long new, int size)
+{
+        unsigned long prev;
+        switch (size) {
+        case 1:
+                __asm__ __volatile__("cmpxchgb %b1,%2"
+                                     : "=a"(prev)
+                                     : "q"(new), "m"(*__xg(ptr)), "0"(old)
+                                     : "memory");
+                return prev;
+        case 2:
+                __asm__ __volatile__("cmpxchgw %w1,%2"
+                                     : "=a"(prev)
+                                     : "r"(new), "m"(*__xg(ptr)), "0"(old)
+                                     : "memory");
+                return prev;
+        case 4:
+                __asm__ __volatile__("cmpxchgl %1,%2"
+                                     : "=a"(prev)
+                                     : "r"(new), "m"(*__xg(ptr)), "0"(old)
+                                     : "memory");
+                return prev;
+        }
+        return old;
+}
+
 #ifndef CONFIG_X86_CMPXCHG
 /*
  * Building a kernel capable running on 80386. It may be necessary to
@@ -403,6 +433,17 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
                                         (unsigned long)(n), sizeof(*(ptr))); \
         __ret;                                                          \
 })
+#define cmpxchg_local(ptr,o,n)                                          \
+({                                                                      \
+        __typeof__(*(ptr)) __ret;                                       \
+        if (likely(boot_cpu_data.x86 > 3))                              \
+                __ret = __cmpxchg_local((ptr), (unsigned long)(o),      \
+                                        (unsigned long)(n), sizeof(*(ptr))); \
+        else                                                            \
+                __ret = cmpxchg_386((ptr), (unsigned long)(o),          \
+                                        (unsigned long)(n), sizeof(*(ptr))); \
+        __ret;                                                          \
+})
 #endif
 
 #ifdef CONFIG_X86_CMPXCHG64
@@ -421,10 +462,26 @@ static inline unsigned long long __cmpxchg64(volatile void *ptr, unsigned long l
         return prev;
 }
 
+static inline unsigned long long __cmpxchg64_local(volatile void *ptr,
+                        unsigned long long old, unsigned long long new)
+{
+        unsigned long long prev;
+        __asm__ __volatile__("cmpxchg8b %3"
+                             : "=A"(prev)
+                             : "b"((unsigned long)new),
+                               "c"((unsigned long)(new >> 32)),
+                               "m"(*__xg(ptr)),
+                               "0"(old)
+                             : "memory");
+        return prev;
+}
+
 #define cmpxchg64(ptr,o,n)\
         ((__typeof__(*(ptr)))__cmpxchg64((ptr),(unsigned long long)(o),\
                                         (unsigned long long)(n)))
-
+#define cmpxchg64_local(ptr,o,n)\
+        ((__typeof__(*(ptr)))__cmpxchg64_local((ptr),(unsigned long long)(o),\
+                                        (unsigned long long)(n)))
 #endif
     
 /*