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atomic: Add testandclear on i386/amd64

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Reviewed by:	kib
Sponsored by:	Microsoft OSTC
Differential Revision:	https://reviews.freebsd.org/D6381
This commit is contained in:
Sepherosa Ziehau 2016-05-16 07:19:33 +00:00
parent 95c6a8211c
commit dfdc9a05c6
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=299912
3 changed files with 83 additions and 1 deletions
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20
share/man/man9/atomic.9
View File

@ -23,7 +23,7 @@
.\"
.\" $FreeBSD$
.\"
.Dd August 14, 2015
.Dd May 12, 2016
.Dt ATOMIC 9
.Os
.Sh NAME
@ -65,6 +65,8 @@
.Ft <type>
.Fn atomic_swap_<type> "volatile <type> *p" "<type> v"
.Ft int
.Fn atomic_testandclear_<type> "volatile <type> *p" "u_int 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 across multiple
@ -309,6 +311,15 @@ and
.Dq Li 16
and do not have any variants with memory barriers at this time.
.Bl -hang
.It Fn atomic_testandclear p v
.Bd -literal -compact
bit = 1 << (v % (sizeof(*p) * NBBY));
tmp = (*p & bit) != 0;
*p &= ~bit;
return (tmp);
.Ed
.El
.Bl -hang
.It Fn atomic_testandset p v
.Bd -literal -compact
bit = 1 << (v % (sizeof(*p) * NBBY));
@ -320,6 +331,8 @@ return (tmp);
.Pp
The
.Fn atomic_testandset
and
.Fn atomic_testandclear
functions are only implemented for the types
.Dq Li int ,
.Dq Li long
@ -348,6 +361,8 @@ and
functions return the value at the specified address.
The
.Fn atomic_testandset
and
.Fn atomic_testandclear
function returns the result of the test operation.
.Sh EXAMPLES
This example uses the
@ -425,3 +440,6 @@ and
.Fn atomic_testandset
operations were added in
.Fx 10.0 .
.Fn atomic_testandclear
operation was added in
.Fx 11.0 .

38
sys/amd64/include/atomic.h
View File

@ -103,6 +103,8 @@ 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);
int atomic_testandclear_int(volatile u_int *p, u_int v);
int atomic_testandclear_long(volatile u_long *p, u_int v);
void atomic_thread_fence_acq(void);
void atomic_thread_fence_acq_rel(void);
void atomic_thread_fence_rel(void);
@ -264,6 +266,40 @@ atomic_testandset_long(volatile u_long *p, u_int v)
return (res);
}
static __inline int
atomic_testandclear_int(volatile u_int *p, u_int v)
{
u_char res;
__asm __volatile(
" " MPLOCKED " "
" btrl %2,%1 ; "
" setc %0 ; "
"# atomic_testandclear_int"
: "=q" (res), /* 0 */
"+m" (*p) /* 1 */
: "Ir" (v & 0x1f) /* 2 */
: "cc");
return (res);
}
static __inline int
atomic_testandclear_long(volatile u_long *p, u_int v)
{
u_char res;
__asm __volatile(
" " MPLOCKED " "
" btrq %2,%1 ; "
" setc %0 ; "
"# atomic_testandclear_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.
@ -537,6 +573,7 @@ u_long atomic_swap_long(volatile u_long *p, u_long v);
#define atomic_readandclear_32 atomic_readandclear_int
#define atomic_fetchadd_32 atomic_fetchadd_int
#define atomic_testandset_32 atomic_testandset_int
#define atomic_testandclear_32 atomic_testandclear_int
/* Operations on 64-bit quad words. */
#define atomic_set_64 atomic_set_long
@ -560,6 +597,7 @@ u_long atomic_swap_long(volatile u_long *p, u_long v);
#define atomic_readandclear_64 atomic_readandclear_long
#define atomic_fetchadd_64 atomic_fetchadd_long
#define atomic_testandset_64 atomic_testandset_long
#define atomic_testandclear_64 atomic_testandclear_long
/* Operations on pointers. */
#define atomic_set_ptr atomic_set_long

26
sys/i386/include/atomic.h
View File

@ -108,6 +108,7 @@ void atomic_##NAME##_barr_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
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);
int atomic_testandclear_int(volatile u_int *p, u_int v);
void atomic_thread_fence_acq(void);
void atomic_thread_fence_acq_rel(void);
void atomic_thread_fence_rel(void);
@ -250,6 +251,23 @@ atomic_testandset_int(volatile u_int *p, u_int v)
return (res);
}
static __inline int
atomic_testandclear_int(volatile u_int *p, u_int v)
{
u_char res;
__asm __volatile(
" " MPLOCKED " "
" btrl %2,%1 ; "
" setc %0 ; "
"# atomic_testandclear_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.
@ -602,6 +620,13 @@ atomic_testandset_long(volatile u_long *p, u_int v)
return (atomic_testandset_int((volatile u_int *)p, v));
}
static __inline int
atomic_testandclear_long(volatile u_long *p, u_int v)
{
return (atomic_testandclear_int((volatile u_int *)p, v));
}
/* Read the current value and store a new value in the destination. */
#ifdef __GNUCLIKE_ASM
@ -728,6 +753,7 @@ u_long atomic_swap_long(volatile u_long *p, u_long v);
#define atomic_readandclear_32 atomic_readandclear_int
#define atomic_fetchadd_32 atomic_fetchadd_int
#define atomic_testandset_32 atomic_testandset_int
#define atomic_testandclear_32 atomic_testandclear_int
/* Operations on pointers. */
#define atomic_set_ptr(p, v) \