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authorMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>2007-05-08 00:34:44 -0700
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-05-08 11:15:20 -0700
commita075227948636e10aa2cc2d8725fbbab27681d4a (patch)
tree6b459363916c4db4cc62a293f122f4c9172b1d6a /include/asm-i386/local.h
parentf43f7b46eb101f50950cfcead0cb0b7a9c4f6823 (diff)
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>
Diffstat (limited to 'include/asm-i386/local.h')
-rw-r--r--include/asm-i386/local.h205
1 files changed, 178 insertions, 27 deletions
diff --git a/include/asm-i386/local.h b/include/asm-i386/local.h
index 12060e22f7e..e13d3e98823 100644
--- a/include/asm-i386/local.h
+++ b/include/asm-i386/local.h
@@ -2,47 +2,198 @@
#define _ARCH_I386_LOCAL_H
#include <linux/percpu.h>
+#include <asm/system.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__(
"incl %0"
- :"+m" (v->counter));
+ :"+m" (l->a.counter));
}
-static __inline__ void local_dec(local_t *v)
+static __inline__ void local_dec(local_t *l)
{
__asm__ __volatile__(
"decl %0"
- :"+m" (v->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__(
"addl %1,%0"
- :"+m" (v->counter)
+ :"+m" (l->a.counter)
:"ir" (i));
}
-static __inline__ void local_sub(long i, local_t *v)
+static __inline__ void local_sub(long i, local_t *l)
{
__asm__ __volatile__(
"subl %1,%0"
- :"+m" (v->counter)
+ :"+m" (l->a.counter)
:"ir" (i));
}
+/**
+ * local_sub_and_test - subtract value from variable and test result
+ * @i: integer value to subtract
+ * @l: pointer of 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__(
+ "subl %2,%0; sete %1"
+ :"+m" (l->a.counter), "=qm" (c)
+ :"ir" (i) : "memory");
+ return c;
+}
+
+/**
+ * local_dec_and_test - decrement and test
+ * @l: pointer of 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__(
+ "decl %0; sete %1"
+ :"+m" (l->a.counter), "=qm" (c)
+ : : "memory");
+ return c != 0;
+}
+
+/**
+ * local_inc_and_test - increment and test
+ * @l: pointer of 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__(
+ "incl %0; sete %1"
+ :"+m" (l->a.counter), "=qm" (c)
+ : : "memory");
+ return c != 0;
+}
+
+/**
+ * local_add_negative - add and test if negative
+ * @l: pointer of type local_t
+ * @i: integer value to add
+ *
+ * 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__(
+ "addl %2,%0; sets %1"
+ :"+m" (l->a.counter), "=qm" (c)
+ :"ir" (i) : "memory");
+ return c;
+}
+
+/**
+ * local_add_return - add and return
+ * @l: pointer of type local_t
+ * @i: integer value to add
+ *
+ * Atomically adds @i to @l and returns @i + @l
+ */
+static __inline__ long local_add_return(long i, local_t *l)
+{
+ long __i;
+#ifdef CONFIG_M386
+ unsigned long flags;
+ if(unlikely(boot_cpu_data.x86==3))
+ goto no_xadd;
+#endif
+ /* Modern 486+ processor */
+ __i = i;
+ __asm__ __volatile__(
+ "xaddl %0, %1;"
+ :"+r" (i), "+m" (l->a.counter)
+ : : "memory");
+ return i + __i;
+
+#ifdef CONFIG_M386
+no_xadd: /* Legacy 386 processor */
+ local_irq_save(flags);
+ __i = local_read(l);
+ local_set(l, i + __i);
+ local_irq_restore(flags);
+ return i + __i;
+#endif
+}
+
+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)))
+
+/**
+ * local_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, these are no better than the atomic variants. */
#define __local_inc(l) local_inc(l)
#define __local_dec(l) local_dec(l)
@@ -56,27 +207,27 @@ 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_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_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(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 */