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[Xen-devel] [PATCH 1/2] asm/atomic.h: common prototyping (add xen/atomic.h)

From: Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx>

Date: Wed, 13 Jul 2016 14:23:08 +0300

Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>, Julien Grall <julien.grall@xxxxxxx>, Stefano Stabellini <sstabellini@xxxxxxxxxx>, Jan Beulich <jbeulich@xxxxxxxx>

Delivery-date: Wed, 13 Jul 2016 11:23:51 +0000

List-id: Xen developer discussion <xen-devel.lists.xen.org>

Following Andrew Cooper's suggestion, create a common-side <xen/atomic.h> to establish, among others, prototypes of atomic functions called from common-code. Done to avoid introducing inconsistencies between arch-side <asm/atomic.h> headers when we make subtle changes to one of them. Some arm-side macros had to be turned into inline functions in the process. Also includes a minor adjustment asm-x86/atomic.h: reorder atomic_inc_and_test() to follow after atomic_inc(). Signed-off-by: Corneliu ZUZU <czuzu@xxxxxxxxxxxxxxx> --- xen/include/asm-arm/arm32/atomic.h | 11 --- xen/include/asm-arm/arm64/atomic.h | 11 --- xen/include/asm-arm/atomic.h | 89 ++++++++++++++++++--- xen/include/asm-x86/atomic.h | 49 +++++------- xen/include/xen/atomic.h | 155 +++++++++++++++++++++++++++++++++++++ 5 files changed, 255 insertions(+), 60 deletions(-) create mode 100644 xen/include/xen/atomic.h diff --git a/xen/include/asm-arm/arm32/atomic.h b/xen/include/asm-arm/arm32/atomic.h index 7ec712f..be08ff1 100644 --- a/xen/include/asm-arm/arm32/atomic.h +++ b/xen/include/asm-arm/arm32/atomic.h @@ -149,17 +149,6 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) -#define atomic_inc(v) atomic_add(1, v) -#define atomic_dec(v) atomic_sub(1, v) - -#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) -#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) -#define atomic_inc_return(v) (atomic_add_return(1, v)) -#define atomic_dec_return(v) (atomic_sub_return(1, v)) -#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) - -#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0) - #endif /* __ARCH_ARM_ARM32_ATOMIC__ */ /* * Local variables: diff --git a/xen/include/asm-arm/arm64/atomic.h b/xen/include/asm-arm/arm64/atomic.h index b49219e..80d07bf 100644 --- a/xen/include/asm-arm/arm64/atomic.h +++ b/xen/include/asm-arm/arm64/atomic.h @@ -125,17 +125,6 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) return c; } -#define atomic_inc(v) atomic_add(1, v) -#define atomic_dec(v) atomic_sub(1, v) - -#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0) -#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0) -#define atomic_inc_return(v) (atomic_add_return(1, v)) -#define atomic_dec_return(v) (atomic_sub_return(1, v)) -#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0) - -#define atomic_add_negative(i,v) (atomic_add_return(i, v) < 0) - #endif /* * Local variables: diff --git a/xen/include/asm-arm/atomic.h b/xen/include/asm-arm/atomic.h index 29ab265..8e8c5d1 100644 --- a/xen/include/asm-arm/atomic.h +++ b/xen/include/asm-arm/atomic.h @@ -2,6 +2,7 @@ #define __ARCH_ARM_ATOMIC__ #include <xen/config.h> +#include <xen/atomic.h> #include <xen/prefetch.h> #include <asm/system.h> @@ -95,15 +96,6 @@ void __bad_atomic_size(void); default: __bad_atomic_size(); break; \ } \ }) - -/* - * NB. I've pushed the volatile qualifier into the operations. This allows - * fast accessors such as _atomic_read() and _atomic_set() which don't give - * the compiler a fit. - */ -typedef struct { int counter; } atomic_t; - -#define ATOMIC_INIT(i) { (i) } /* * On ARM, ordinary assignment (str instruction) doesn't clear the local @@ -138,6 +130,85 @@ static inline void _atomic_set(atomic_t *v, int i) # error "unknown ARM variant" #endif +#define atomic_inc_return(v) (atomic_add_return(1, v)) +#define atomic_dec_return(v) (atomic_sub_return(1, v)) + +/** + * atomic_sub_and_test - subtract value from variable and test result + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v and returns + * true if the result is zero, or false for all + * other cases. + */ +static inline int atomic_sub_and_test(int i, atomic_t *v) +{ + return 0 == atomic_sub_return(i, v); +} + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +static inline void atomic_inc(atomic_t *v) +{ + atomic_add(1, v); +} + +/** + * atomic_inc_and_test - increment and test + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +static inline int atomic_inc_and_test(atomic_t *v) +{ + return 0 == atomic_add_return(1, v); +} + +/** + * atomic_dec - decrement atomic variable + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1. + */ +static inline void atomic_dec(atomic_t *v) +{ + atomic_sub(1, v); +} + +/** + * atomic_dec_and_test - decrement and test + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +static inline int atomic_dec_and_test(atomic_t *v) +{ + return 0 == atomic_sub_return(1, v); +} + +/** + * atomic_add_negative - add and test if negative + * @v: pointer of type atomic_t + * @i: integer value to add + * + * Atomically adds @i to @v and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +static inline int atomic_add_negative(int i, atomic_t *v) +{ + return atomic_add_return(i, v) < 0; +} + #endif /* __ARCH_ARM_ATOMIC__ */ /* * Local variables: diff --git a/xen/include/asm-x86/atomic.h b/xen/include/asm-x86/atomic.h index d246b70..9bf4bc1 100644 --- a/xen/include/asm-x86/atomic.h +++ b/xen/include/asm-x86/atomic.h @@ -2,6 +2,7 @@ #define __ARCH_X86_ATOMIC__ #include <xen/config.h> +#include <xen/atomic.h> #include <asm/system.h> #define build_read_atomic(name, size, type, reg, barrier) \ @@ -79,15 +80,6 @@ void __bad_atomic_size(void); } \ }) -/* - * NB. I've pushed the volatile qualifier into the operations. This allows - * fast accessors such as _atomic_read() and _atomic_set() which don't give - * the compiler a fit. - */ -typedef struct { int counter; } atomic_t; - -#define ATOMIC_INIT(i) { (i) } - /** * atomic_read - read atomic variable * @v: pointer of type atomic_t @@ -110,7 +102,6 @@ static inline int _atomic_read(atomic_t v) return v.counter; } - /** * atomic_set - set atomic variable * @v: pointer of type atomic_t @@ -217,6 +208,25 @@ static inline void atomic_inc(atomic_t *v) } /** + * atomic_inc_and_test - increment and test + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +static inline int atomic_inc_and_test(atomic_t *v) +{ + unsigned char c; + + asm volatile ( + "lock; incl %0; sete %1" + : "=m" (*(volatile int *)&v->counter), "=qm" (c) + : "m" (*(volatile int *)&v->counter) : "memory" ); + return c != 0; +} + +/** * atomic_dec - decrement atomic variable * @v: pointer of type atomic_t * @@ -250,25 +260,6 @@ static inline int atomic_dec_and_test(atomic_t *v) } /** - * atomic_inc_and_test - increment and test - * @v: pointer of type atomic_t - * - * Atomically increments @v by 1 - * and returns true if the result is zero, or false for all - * other cases. - */ -static inline int atomic_inc_and_test(atomic_t *v) -{ - unsigned char c; - - asm volatile ( - "lock; incl %0; sete %1" - : "=m" (*(volatile int *)&v->counter), "=qm" (c) - : "m" (*(volatile int *)&v->counter) : "memory" ); - return c != 0; -} - -/** * atomic_add_negative - add and test if negative * @v: pointer of type atomic_t * @i: integer value to add diff --git a/xen/include/xen/atomic.h b/xen/include/xen/atomic.h new file mode 100644 index 0000000..5d5c051 --- /dev/null +++ b/xen/include/xen/atomic.h @@ -0,0 +1,155 @@ +/* + * include/xen/atomic.h + * + * Common atomic operations entities (atomic_t, function prototypes). + * Include _from_ arch-side <asm/atomic.h>. + * + * Copyright (c) 2016 Bitdefender S.R.L. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; If not, see <http://www.gnu.org/licenses/>. + */ + +#ifndef __XEN_ATOMIC_H__ +#define __XEN_ATOMIC_H__ + +/* + * NB. I've pushed the volatile qualifier into the operations. This allows + * fast accessors such as _atomic_read() and _atomic_set() which don't give + * the compiler a fit. + */ +typedef struct { int counter; } atomic_t; + +#define ATOMIC_INIT(i) { (i) } + +/** + * atomic_read - read atomic variable + * @v: pointer of type atomic_t + * + * Atomically reads the value of @v. + */ +static inline int atomic_read(atomic_t *v); + +/** + * _atomic_read - read atomic variable non-atomically + * @v atomic_t + * + * Non-atomically reads the value of @v + */ +static inline int _atomic_read(atomic_t v); + +/** + * atomic_set - set atomic variable + * @v: pointer of type atomic_t + * @i: required value + * + * Atomically sets the value of @v to @i. + */ +static inline void atomic_set(atomic_t *v, int i); + +/** + * _atomic_set - set atomic variable non-atomically + * @v: pointer of type atomic_t + * @i: required value + * + * Non-atomically sets the value of @v to @i. + */ +static inline void _atomic_set(atomic_t *v, int i); + +static inline int atomic_cmpxchg(atomic_t *v, int old, int new); + +/** + * atomic_add - add integer to atomic variable + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v. + */ +static inline void atomic_add(int i, atomic_t *v); + +/** + * atomic_add_return - add integer and return + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v and returns @i + @v + */ +static inline int atomic_add_return(int i, atomic_t *v); + +/** + * atomic_sub - subtract the atomic variable + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v. + */ +static inline void atomic_sub(int i, atomic_t *v); + +/** + * atomic_sub_and_test - subtract value from variable and test result + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v and returns + * true if the result is zero, or false for all + * other cases. + */ +static inline int atomic_sub_and_test(int i, atomic_t *v); + +/** + * atomic_inc - increment atomic variable + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1. + */ +static inline void atomic_inc(atomic_t *v); + +/** + * atomic_inc_and_test - increment and test + * @v: pointer of type atomic_t + * + * Atomically increments @v by 1 + * and returns true if the result is zero, or false for all + * other cases. + */ +static inline int atomic_inc_and_test(atomic_t *v); + +/** + * atomic_dec - decrement atomic variable + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1. + */ +static inline void atomic_dec(atomic_t *v); + +/** + * atomic_dec_and_test - decrement and test + * @v: pointer of type atomic_t + * + * Atomically decrements @v by 1 and + * returns true if the result is 0, or false for all other + * cases. + */ +static inline int atomic_dec_and_test(atomic_t *v); + +/** + * atomic_add_negative - add and test if negative + * @v: pointer of type atomic_t + * @i: integer value to add + * + * Atomically adds @i to @v and returns true + * if the result is negative, or false when + * result is greater than or equal to zero. + */ +static inline int atomic_add_negative(int i, atomic_t *v); + +#endif /* __XEN_ATOMIC_H__ */ -- 2.5.0 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel

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