svn commit: r254617 - in head: share/man/man9 sys/amd64/include sys/i386/include
Jung-uk Kim
jkim at FreeBSD.org
Wed Aug 21 22:03:07 UTC 2013
Author: jkim
Date: Wed Aug 21 22:03:06 2013
New Revision: 254617
URL: http://svnweb.freebsd.org/changeset/base/254617
Log:
Implement atomic_swap() and atomic_testandset().
Reviewed by: arch, bde, jilles, kib
Modified:
head/share/man/man9/atomic.9
head/sys/amd64/include/atomic.h
head/sys/i386/include/atomic.h
Modified: head/share/man/man9/atomic.9
==============================================================================
--- head/share/man/man9/atomic.9 Wed Aug 21 21:47:56 2013 (r254616)
+++ head/share/man/man9/atomic.9 Wed Aug 21 22:03:06 2013 (r254617)
@@ -23,7 +23,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd September 27, 2005
+.Dd August 20, 2013
.Dt ATOMIC 9
.Os
.Sh NAME
@@ -62,6 +62,10 @@
.Fn atomic_subtract_[acq_|rel_]<type> "volatile <type> *p" "<type> v"
.Ft void
.Fn atomic_store_rel_<type> "volatile <type> *p" "<type> v"
+.Ft <type>
+.Fn atomic_swap_<type> "volatile <type> *p" "<type> v"
+.Ft int
+.Fn atomic_testandset_<type> "volatile <type> *p" "u_int v"
.Sh DESCRIPTION
Each of the atomic operations is guaranteed to be atomic in the presence of
interrupts.
@@ -184,9 +188,9 @@ This section describes the semantics of
.Bd -literal -compact
if (*dst == old) {
*dst = new;
- return 1;
+ return (1);
} else
- return 0;
+ return (0);
.Ed
.El
.Pp
@@ -203,7 +207,7 @@ and
.Bd -literal -compact
tmp = *p;
*p += v;
-return tmp;
+return (tmp);
.Ed
.El
.Pp
@@ -216,9 +220,9 @@ and
.Dq Li 32
and do not have any variants with memory barriers at this time.
.Bl -hang
-.It Fn atomic_load addr
+.It Fn atomic_load p
.Bd -literal -compact
-return (*addr)
+return (*p);
.Ed
.El
.Pp
@@ -226,11 +230,11 @@ The
.Fn atomic_load
functions are only provided with acquire memory barriers.
.Bl -hang
-.It Fn atomic_readandclear addr
+.It Fn atomic_readandclear p
.Bd -literal -compact
-temp = *addr;
-*addr = 0;
-return (temp);
+tmp = *p;
+*p = 0;
+return (tmp);
.Ed
.El
.Pp
@@ -243,8 +247,7 @@ functions are not implemented for the ty
.Dq Li 8 ,
and
.Dq Li 16
-and do
-not have any variants with memory barriers at this time.
+and do not have any variants with memory barriers at this time.
.Bl -hang
.It Fn atomic_set p v
.Bd -literal -compact
@@ -264,6 +267,44 @@ The
.Fn atomic_store
functions are only provided with release memory barriers.
.Pp
+.Bl -hang
+.It Fn atomic_swap p v
+.Bd -literal -compact
+tmp = *p;
+*p = v;
+return (tmp);
+.Ed
+.El
+.Pp
+The
+.Fn atomic_swap
+functions are not implemented for the types
+.Dq Li char ,
+.Dq Li short ,
+.Dq Li ptr ,
+.Dq Li 8 ,
+and
+.Dq Li 16
+and do not have any variants with memory barriers at this time.
+.Bl -hang
+.It Fn atomic_testandset p v
+.Bd -literal -compact
+bit = 1 << (v % (sizeof(*p) * NBBY));
+tmp = (*p & bit) != 0;
+*p |= bit;
+return (tmp);
+.Ed
+.El
+.Pp
+The
+.Fn atomic_testandset
+functions are only implemented for the types
+.Dq Li int ,
+.Dq Li long
+and
+.Dq Li 32
+and do not have any variants with memory barriers at this time.
+.Pp
The type
.Dq Li 64
is currently not implemented for any of the atomic operations on the
@@ -275,15 +316,17 @@ architectures.
.Sh RETURN VALUES
The
.Fn atomic_cmpset
-function
-returns the result of the compare operation.
+function returns the result of the compare operation.
The
.Fn atomic_fetchadd ,
.Fn atomic_load ,
+.Fn atomic_readandclear ,
and
-.Fn atomic_readandclear
-functions
-return the value at the specified address.
+.Fn atomic_swap
+functions return the value at the specified address.
+The
+.Fn atomic_testandset
+function returns the result of the test operation.
.Sh EXAMPLES
This example uses the
.Fn atomic_cmpset_acq_ptr
@@ -354,3 +397,9 @@ The
.Fn atomic_fetchadd
operations were added in
.Fx 6.0 .
+The
+.Fn atomic_swap
+and
+.Fn atomic_testandset
+operations were added in
+.Fx 10.0 .
Modified: head/sys/amd64/include/atomic.h
==============================================================================
--- head/sys/amd64/include/atomic.h Wed Aug 21 21:47:56 2013 (r254616)
+++ head/sys/amd64/include/atomic.h Wed Aug 21 22:03:06 2013 (r254617)
@@ -54,12 +54,14 @@
* atomic_clear_int(P, V) (*(u_int *)(P) &= ~(V))
* atomic_add_int(P, V) (*(u_int *)(P) += (V))
* atomic_subtract_int(P, V) (*(u_int *)(P) -= (V))
+ * atomic_swap_int(P, V) (return (*(u_int *)(P)); *(u_int *)(P) = (V);)
* atomic_readandclear_int(P) (return (*(u_int *)(P)); *(u_int *)(P) = 0;)
*
* atomic_set_long(P, V) (*(u_long *)(P) |= (V))
* atomic_clear_long(P, V) (*(u_long *)(P) &= ~(V))
* atomic_add_long(P, V) (*(u_long *)(P) += (V))
* atomic_subtract_long(P, V) (*(u_long *)(P) -= (V))
+ * atomic_swap_long(P, V) (return (*(u_long *)(P)); *(u_long *)(P) = (V);)
* atomic_readandclear_long(P) (return (*(u_long *)(P)); *(u_long *)(P) = 0;)
*/
@@ -80,6 +82,8 @@ int atomic_cmpset_int(volatile u_int *ds
int atomic_cmpset_long(volatile u_long *dst, u_long expect, u_long src);
u_int atomic_fetchadd_int(volatile u_int *p, u_int v);
u_long atomic_fetchadd_long(volatile u_long *p, u_long v);
+int atomic_testandset_int(volatile u_int *p, u_int v);
+int atomic_testandset_long(volatile u_long *p, u_int v);
#define ATOMIC_LOAD(TYPE, LOP) \
u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p)
@@ -205,6 +209,40 @@ atomic_fetchadd_long(volatile u_long *p,
return (v);
}
+static __inline int
+atomic_testandset_int(volatile u_int *p, u_int v)
+{
+ u_char res;
+
+ __asm __volatile(
+ " " MPLOCKED " "
+ " btsl %2,%1 ; "
+ " setc %0 ; "
+ "# atomic_testandset_int"
+ : "=q" (res), /* 0 */
+ "+m" (*p) /* 1 */
+ : "Ir" (v & 0x1f) /* 2 */
+ : "cc");
+ return (res);
+}
+
+static __inline int
+atomic_testandset_long(volatile u_long *p, u_int v)
+{
+ u_char res;
+
+ __asm __volatile(
+ " " MPLOCKED " "
+ " btsq %2,%1 ; "
+ " setc %0 ; "
+ "# atomic_testandset_long"
+ : "=q" (res), /* 0 */
+ "+m" (*p) /* 1 */
+ : "Jr" ((u_long)(v & 0x3f)) /* 2 */
+ : "cc");
+ return (res);
+}
+
/*
* We assume that a = b will do atomic loads and stores. Due to the
* IA32 memory model, a simple store guarantees release semantics.
@@ -296,43 +334,39 @@ ATOMIC_STORE(long);
#ifndef WANT_FUNCTIONS
-/* Read the current value and store a zero in the destination. */
+/* Read the current value and store a new value in the destination. */
#ifdef __GNUCLIKE_ASM
static __inline u_int
-atomic_readandclear_int(volatile u_int *p)
+atomic_swap_int(volatile u_int *p, u_int v)
{
- u_int res;
- res = 0;
__asm __volatile(
" xchgl %1,%0 ; "
- "# atomic_readandclear_int"
- : "+r" (res), /* 0 */
+ "# atomic_swap_int"
+ : "+r" (v), /* 0 */
"+m" (*p)); /* 1 */
- return (res);
+ return (v);
}
static __inline u_long
-atomic_readandclear_long(volatile u_long *p)
+atomic_swap_long(volatile u_long *p, u_long v)
{
- u_long res;
- res = 0;
__asm __volatile(
" xchgq %1,%0 ; "
- "# atomic_readandclear_long"
- : "+r" (res), /* 0 */
+ "# atomic_swap_long"
+ : "+r" (v), /* 0 */
"+m" (*p)); /* 1 */
- return (res);
+ return (v);
}
#else /* !__GNUCLIKE_ASM */
-u_int atomic_readandclear_int(volatile u_int *p);
-u_long atomic_readandclear_long(volatile u_long *p);
+u_int atomic_swap_int(volatile u_int *p, u_int v);
+u_long atomic_swap_long(volatile u_long *p, u_long v);
#endif /* __GNUCLIKE_ASM */
@@ -376,6 +410,9 @@ u_long atomic_readandclear_long(volatile
#define atomic_cmpset_acq_long atomic_cmpset_long
#define atomic_cmpset_rel_long atomic_cmpset_long
+#define atomic_readandclear_int(p) atomic_swap_int(p, 0)
+#define atomic_readandclear_long(p) atomic_swap_long(p, 0)
+
/* Operations on 8-bit bytes. */
#define atomic_set_8 atomic_set_char
#define atomic_set_acq_8 atomic_set_acq_char
@@ -426,8 +463,10 @@ u_long atomic_readandclear_long(volatile
#define atomic_cmpset_32 atomic_cmpset_int
#define atomic_cmpset_acq_32 atomic_cmpset_acq_int
#define atomic_cmpset_rel_32 atomic_cmpset_rel_int
+#define atomic_swap_32 atomic_swap_int
#define atomic_readandclear_32 atomic_readandclear_int
#define atomic_fetchadd_32 atomic_fetchadd_int
+#define atomic_testandset_32 atomic_testandset_int
/* Operations on 64-bit quad words. */
#define atomic_set_64 atomic_set_long
@@ -447,7 +486,9 @@ u_long atomic_readandclear_long(volatile
#define atomic_cmpset_64 atomic_cmpset_long
#define atomic_cmpset_acq_64 atomic_cmpset_acq_long
#define atomic_cmpset_rel_64 atomic_cmpset_rel_long
+#define atomic_swap_64 atomic_swap_long
#define atomic_readandclear_64 atomic_readandclear_long
+#define atomic_testandset_64 atomic_testandset_long
/* Operations on pointers. */
#define atomic_set_ptr atomic_set_long
@@ -467,6 +508,7 @@ u_long atomic_readandclear_long(volatile
#define atomic_cmpset_ptr atomic_cmpset_long
#define atomic_cmpset_acq_ptr atomic_cmpset_acq_long
#define atomic_cmpset_rel_ptr atomic_cmpset_rel_long
+#define atomic_swap_ptr atomic_swap_long
#define atomic_readandclear_ptr atomic_readandclear_long
#endif /* !WANT_FUNCTIONS */
Modified: head/sys/i386/include/atomic.h
==============================================================================
--- head/sys/i386/include/atomic.h Wed Aug 21 21:47:56 2013 (r254616)
+++ head/sys/i386/include/atomic.h Wed Aug 21 22:03:06 2013 (r254617)
@@ -54,12 +54,14 @@
* atomic_clear_int(P, V) (*(u_int *)(P) &= ~(V))
* atomic_add_int(P, V) (*(u_int *)(P) += (V))
* atomic_subtract_int(P, V) (*(u_int *)(P) -= (V))
+ * atomic_swap_int(P, V) (return (*(u_int *)(P)); *(u_int *)(P) = (V);)
* atomic_readandclear_int(P) (return (*(u_int *)(P)); *(u_int *)(P) = 0;)
*
* atomic_set_long(P, V) (*(u_long *)(P) |= (V))
* atomic_clear_long(P, V) (*(u_long *)(P) &= ~(V))
* atomic_add_long(P, V) (*(u_long *)(P) += (V))
* atomic_subtract_long(P, V) (*(u_long *)(P) -= (V))
+ * atomic_swap_long(P, V) (return (*(u_long *)(P)); *(u_long *)(P) = (V);)
* atomic_readandclear_long(P) (return (*(u_long *)(P)); *(u_long *)(P) = 0;)
*/
@@ -78,6 +80,7 @@ void atomic_##NAME##_barr_##TYPE(volatil
int atomic_cmpset_int(volatile u_int *dst, u_int expect, u_int src);
u_int atomic_fetchadd_int(volatile u_int *p, u_int v);
+int atomic_testandset_int(volatile u_int *p, u_int v);
#define ATOMIC_LOAD(TYPE, LOP) \
u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p)
@@ -275,6 +278,23 @@ atomic_fetchadd_int(volatile u_int *p, u
return (v);
}
+static __inline int
+atomic_testandset_int(volatile u_int *p, u_int v)
+{
+ u_char res;
+
+ __asm __volatile(
+ " " MPLOCKED " "
+ " btsl %2,%1 ; "
+ " setc %0 ; "
+ "# atomic_testandset_int"
+ : "=q" (res), /* 0 */
+ "+m" (*p) /* 1 */
+ : "Ir" (v & 0x1f) /* 2 */
+ : "cc");
+ return (res);
+}
+
/*
* We assume that a = b will do atomic loads and stores. Due to the
* IA32 memory model, a simple store guarantees release semantics.
@@ -386,43 +406,40 @@ atomic_fetchadd_long(volatile u_long *p,
return (atomic_fetchadd_int((volatile u_int *)p, (u_int)v));
}
-/* Read the current value and store a zero in the destination. */
+static __inline int
+atomic_testandset_long(volatile u_long *p, u_int v)
+{
+
+ return (atomic_testandset_int((volatile u_int *)p, v));
+}
+
+/* Read the current value and store a new value in the destination. */
#ifdef __GNUCLIKE_ASM
static __inline u_int
-atomic_readandclear_int(volatile u_int *p)
+atomic_swap_int(volatile u_int *p, u_int v)
{
- u_int res;
- res = 0;
__asm __volatile(
" xchgl %1,%0 ; "
- "# atomic_readandclear_int"
- : "+r" (res), /* 0 */
+ "# atomic_swap_int"
+ : "+r" (v), /* 0 */
"+m" (*p)); /* 1 */
- return (res);
+ return (v);
}
static __inline u_long
-atomic_readandclear_long(volatile u_long *p)
+atomic_swap_long(volatile u_long *p, u_long v)
{
- u_long res;
- res = 0;
- __asm __volatile(
- " xchgl %1,%0 ; "
- "# atomic_readandclear_long"
- : "+r" (res), /* 0 */
- "+m" (*p)); /* 1 */
-
- return (res);
+ return (atomic_swap_int((volatile u_int *)p, (u_int)v));
}
#else /* !__GNUCLIKE_ASM */
-u_int atomic_readandclear_int(volatile u_int *p);
-u_long atomic_readandclear_long(volatile u_long *p);
+u_int atomic_swap_int(volatile u_int *p, u_int v);
+u_long atomic_swap_long(volatile u_long *p, u_long v);
#endif /* __GNUCLIKE_ASM */
@@ -466,6 +483,9 @@ u_long atomic_readandclear_long(volatile
#define atomic_cmpset_acq_long atomic_cmpset_long
#define atomic_cmpset_rel_long atomic_cmpset_long
+#define atomic_readandclear_int(p) atomic_swap_int(p, 0)
+#define atomic_readandclear_long(p) atomic_swap_long(p, 0)
+
/* Operations on 8-bit bytes. */
#define atomic_set_8 atomic_set_char
#define atomic_set_acq_8 atomic_set_acq_char
@@ -516,8 +536,10 @@ u_long atomic_readandclear_long(volatile
#define atomic_cmpset_32 atomic_cmpset_int
#define atomic_cmpset_acq_32 atomic_cmpset_acq_int
#define atomic_cmpset_rel_32 atomic_cmpset_rel_int
+#define atomic_swap_32 atomic_swap_int
#define atomic_readandclear_32 atomic_readandclear_int
#define atomic_fetchadd_32 atomic_fetchadd_int
+#define atomic_testandset_32 atomic_testandset_int
/* Operations on pointers. */
#define atomic_set_ptr(p, v) \
@@ -556,6 +578,8 @@ u_long atomic_readandclear_long(volatile
#define atomic_cmpset_rel_ptr(dst, old, new) \
atomic_cmpset_rel_int((volatile u_int *)(dst), (u_int)(old), \
(u_int)(new))
+#define atomic_swap_ptr(p, v) \
+ atomic_swap_int((volatile u_int *)(p), (u_int)(v))
#define atomic_readandclear_ptr(p) \
atomic_readandclear_int((volatile u_int *)(p))
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