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author | sephe <sephe@FreeBSD.org> | 2016-05-16 07:19:33 +0000 |
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committer | sephe <sephe@FreeBSD.org> | 2016-05-16 07:19:33 +0000 |
commit | 6babf965828710aa3c7eb1948adf394eec4601b1 (patch) | |
tree | 9f6d7e8698ecfb3feae93b6fe79b6d8f9f7ca071 | |
parent | 418cf336012cc2640bff1cb21b871fe144513730 (diff) | |
download | FreeBSD-src-6babf965828710aa3c7eb1948adf394eec4601b1.zip FreeBSD-src-6babf965828710aa3c7eb1948adf394eec4601b1.tar.gz |
atomic: Add testandclear on i386/amd64
Reviewed by: kib
Sponsored by: Microsoft OSTC
Differential Revision: https://reviews.freebsd.org/D6381
-rw-r--r-- | share/man/man9/atomic.9 | 20 | ||||
-rw-r--r-- | sys/amd64/include/atomic.h | 38 | ||||
-rw-r--r-- | sys/i386/include/atomic.h | 26 |
3 files changed, 83 insertions, 1 deletions
diff --git a/share/man/man9/atomic.9 b/share/man/man9/atomic.9 index cee30e6..e085a78 100644 --- a/share/man/man9/atomic.9 +++ b/share/man/man9/atomic.9 @@ -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 . diff --git a/sys/amd64/include/atomic.h b/sys/amd64/include/atomic.h index dd71e92..c9526f4 100644 --- a/sys/amd64/include/atomic.h +++ b/sys/amd64/include/atomic.h @@ -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 diff --git a/sys/i386/include/atomic.h b/sys/i386/include/atomic.h index 3242d76..90fb950 100644 --- a/sys/i386/include/atomic.h +++ b/sys/i386/include/atomic.h @@ -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) \ |