local_t: x86_64 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>

diff --git a/include/asm-x86_64/local.h b/include/asm-x86_64/local.h
index e769e620022530c751a244f1b83e301d683d1d2a..e87492bb0693eeb8d533db17c34067a45a5bd92a 100644 (file)
--- a/include/asm-x86_64/local.h
+++ b/include/asm-x86_64/local.h
@@ -2,49 +2,183 @@
 #define _ARCH_X8664_LOCAL_H
 
 #include <linux/percpu.h>
+#include <asm/atomic.h>
 
 typedef struct
 {
-       volatile long counter;
+       atomic_long_t a;
 } local_t;
 
-#define LOCAL_INIT(i)  { (i) }
+#define LOCAL_INIT(i)  { ATOMIC_LONG_INIT(i) }
 
-#define local_read(v)  ((v)->counter)
-#define local_set(v,i) (((v)->counter) = (i))
+#define local_read(l)  atomic_long_read(&(l)->a)
+#define local_set(l,i) atomic_long_set(&(l)->a, (i))
 
-static inline void local_inc(local_t *v)
+static inline void local_inc(local_t *l)
 {
        __asm__ __volatile__(
                "incq %0"
-               :"=m" (v->counter)
-               :"m" (v->counter));
+               :"=m" (l->a.counter)
+               :"m" (l->a.counter));
 }
 
-static inline void local_dec(local_t *v)
+static inline void local_dec(local_t *l)
 {
        __asm__ __volatile__(
                "decq %0"
-               :"=m" (v->counter)
-               :"m" (v->counter));
+               :"=m" (l->a.counter)
+               :"m" (l->a.counter));
 }
 
-static inline void local_add(long i, local_t *v)
+static inline void local_add(long i, local_t *l)
 {
        __asm__ __volatile__(
                "addq %1,%0"
-               :"=m" (v->counter)
-               :"ir" (i), "m" (v->counter));
+               :"=m" (l->a.counter)
+               :"ir" (i), "m" (l->a.counter));
 }
 
-static inline void local_sub(long i, local_t *v)
+static inline void local_sub(long i, local_t *l)
 {
        __asm__ __volatile__(
                "subq %1,%0"
-               :"=m" (v->counter)
-               :"ir" (i), "m" (v->counter));
+               :"=m" (l->a.counter)
+               :"ir" (i), "m" (l->a.counter));
 }
 
+/**
+ * local_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @l: pointer to type local_t
+ *
+ * Atomically subtracts @i from @l and returns
+ * true if the result is zero, or false for all
+ * other cases.
+ */
+static __inline__ int local_sub_and_test(long i, local_t *l)
+{
+       unsigned char c;
+
+       __asm__ __volatile__(
+               "subq %2,%0; sete %1"
+               :"=m" (l->a.counter), "=qm" (c)
+               :"ir" (i), "m" (l->a.counter) : "memory");
+       return c;
+}
+
+/**
+ * local_dec_and_test - decrement and test
+ * @l: pointer to type local_t
+ *
+ * Atomically decrements @l by 1 and
+ * returns true if the result is 0, or false for all other
+ * cases.
+ */
+static __inline__ int local_dec_and_test(local_t *l)
+{
+       unsigned char c;
+
+       __asm__ __volatile__(
+               "decq %0; sete %1"
+               :"=m" (l->a.counter), "=qm" (c)
+               :"m" (l->a.counter) : "memory");
+       return c != 0;
+}
+
+/**
+ * local_inc_and_test - increment and test
+ * @l: pointer to type local_t
+ *
+ * Atomically increments @l by 1
+ * and returns true if the result is zero, or false for all
+ * other cases.
+ */
+static __inline__ int local_inc_and_test(local_t *l)
+{
+       unsigned char c;
+
+       __asm__ __volatile__(
+               "incq %0; sete %1"
+               :"=m" (l->a.counter), "=qm" (c)
+               :"m" (l->a.counter) : "memory");
+       return c != 0;
+}
+
+/**
+ * local_add_negative - add and test if negative
+ * @i: integer value to add
+ * @l: pointer to type local_t
+ *
+ * Atomically adds @i to @l and returns true
+ * if the result is negative, or false when
+ * result is greater than or equal to zero.
+ */
+static __inline__ int local_add_negative(long i, local_t *l)
+{
+       unsigned char c;
+
+       __asm__ __volatile__(
+               "addq %2,%0; sets %1"
+               :"=m" (l->a.counter), "=qm" (c)
+               :"ir" (i), "m" (l->a.counter) : "memory");
+       return c;
+}
+
+/**
+ * local_add_return - add and return
+ * @i: integer value to add
+ * @l: pointer to type local_t
+ *
+ * Atomically adds @i to @l and returns @i + @l
+ */
+static __inline__ long local_add_return(long i, local_t *l)
+{
+       long __i = i;
+       __asm__ __volatile__(
+               "xaddq %0, %1;"
+               :"+r" (i), "+m" (l->a.counter)
+               : : "memory");
+       return i + __i;
+}
+
+static __inline__ long local_sub_return(long i, local_t *l)
+{
+       return local_add_return(-i,l);
+}
+
+#define local_inc_return(l)  (local_add_return(1,l))
+#define local_dec_return(l)  (local_sub_return(1,l))
+
+#define local_cmpxchg(l, o, n) \
+       (cmpxchg_local(&((l)->a.counter), (o), (n)))
+/* Always has a lock prefix */
+#define local_xchg(l, n) (xchg(&((l)->a.counter), (n)))
+
+/**
+ * atomic_up_add_unless - add unless the number is a given value
+ * @l: pointer of type local_t
+ * @a: the amount to add to l...
+ * @u: ...unless l is equal to u.
+ *
+ * Atomically adds @a to @l, so long as it was not @u.
+ * Returns non-zero if @l was not @u, and zero otherwise.
+ */
+#define local_add_unless(l, a, u)                              \
+({                                                             \
+       long c, old;                                            \
+       c = local_read(l);                                      \
+       for (;;) {                                              \
+               if (unlikely(c == (u)))                         \
+                       break;                                  \
+               old = local_cmpxchg((l), c, c + (a));   \
+               if (likely(old == c))                           \
+                       break;                                  \
+               c = old;                                        \
+       }                                                       \
+       c != (u);                                               \
+})
+#define local_inc_not_zero(l) local_add_unless((l), 1, 0)
+
 /* On x86-64 these are better than the atomic variants on SMP kernels
    because they dont use a lock prefix. */
 #define __local_inc(l)         local_inc(l)
@@ -62,27 +196,27 @@ static inline void local_sub(long i, local_t *v)
 
 /* Need to disable preemption for the cpu local counters otherwise we could
    still access a variable of a previous CPU in a non atomic way. */
-#define cpu_local_wrap_v(v)            \
+#define cpu_local_wrap_v(l)            \
        ({ local_t res__;               \
           preempt_disable();           \
-          res__ = (v);                 \
+          res__ = (l);                 \
           preempt_enable();            \
           res__; })
-#define cpu_local_wrap(v)              \
+#define cpu_local_wrap(l)              \
        ({ preempt_disable();           \
-          v;                           \
+          l;                           \
           preempt_enable(); })         \
 
-#define cpu_local_read(v)    cpu_local_wrap_v(local_read(&__get_cpu_var(v)))
-#define cpu_local_set(v, i)  cpu_local_wrap(local_set(&__get_cpu_var(v), (i)))
-#define cpu_local_inc(v)     cpu_local_wrap(local_inc(&__get_cpu_var(v)))
-#define cpu_local_dec(v)     cpu_local_wrap(local_dec(&__get_cpu_var(v)))
-#define cpu_local_add(i, v)  cpu_local_wrap(local_add((i), &__get_cpu_var(v)))
-#define cpu_local_sub(i, v)  cpu_local_wrap(local_sub((i), &__get_cpu_var(v)))
+#define cpu_local_read(l)    cpu_local_wrap_v(local_read(&__get_cpu_var(l)))
+#define cpu_local_set(l, i)  cpu_local_wrap(local_set(&__get_cpu_var(l), (i)))
+#define cpu_local_inc(l)     cpu_local_wrap(local_inc(&__get_cpu_var(l)))
+#define cpu_local_dec(l)     cpu_local_wrap(local_dec(&__get_cpu_var(l)))
+#define cpu_local_add(i, l)  cpu_local_wrap(local_add((i), &__get_cpu_var(l)))
+#define cpu_local_sub(i, l)  cpu_local_wrap(local_sub((i), &__get_cpu_var(l)))
 
-#define __cpu_local_inc(v)     cpu_local_inc(v)
-#define __cpu_local_dec(v)     cpu_local_dec(v)
-#define __cpu_local_add(i, v)  cpu_local_add((i), (v))
-#define __cpu_local_sub(i, v)  cpu_local_sub((i), (v))
+#define __cpu_local_inc(l)     cpu_local_inc(l)
+#define __cpu_local_dec(l)     cpu_local_dec(l)
+#define __cpu_local_add(i, l)  cpu_local_add((i), (l))
+#define __cpu_local_sub(i, l)  cpu_local_sub((i), (l))
 
-#endif /* _ARCH_I386_LOCAL_H */
+#endif /* _ARCH_X8664_LOCAL_H */

diff --git a/include/asm-x86_64/system.h b/include/asm-x86_64/system.h
index 213b7fe5d998235c5e1d99266c5b358655ac0b41..1f1c0bf4a5df9d361a72a4bc3a99f26b545be5ea 100644 (file)
--- a/include/asm-x86_64/system.h
+++ b/include/asm-x86_64/system.h
@@ -214,9 +214,45 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
        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 %k1,%2"
+                                    : "=a"(prev)
+                                    : "r"(new), "m"(*__xg(ptr)), "0"(old)
+                                    : "memory");
+               return prev;
+       case 8:
+               __asm__ __volatile__("cmpxchgq %1,%2"
+                                    : "=a"(prev)
+                                    : "r"(new), "m"(*__xg(ptr)), "0"(old)
+                                    : "memory");
+               return prev;
+       }
+       return old;
+}
+
 #define cmpxchg(ptr,o,n)\
        ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
                                        (unsigned long)(n),sizeof(*(ptr))))
+#define cmpxchg_local(ptr,o,n)\
+       ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
+                                       (unsigned long)(n),sizeof(*(ptr))))
 
 #ifdef CONFIG_SMP
 #define smp_mb()       mb()