Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754028AbbLOOnx (ORCPT ); Tue, 15 Dec 2015 09:43:53 -0500 Received: from mail-pf0-f193.google.com ([209.85.192.193]:34931 "EHLO mail-pf0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751996AbbLOOnw (ORCPT ); Tue, 15 Dec 2015 09:43:52 -0500 X-Greylist: delayed 1126 seconds by postgrey-1.27 at vger.kernel.org; Tue, 15 Dec 2015 09:43:52 EST From: Boqun Feng To: linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: Peter Zijlstra , Ingo Molnar , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Will Deacon , "Paul E. McKenney" , Waiman Long , Davidlohr Bueso , Boqun Feng Subject: [PATCH v6 3/4] powerpc: atomic: Implement acquire/release/relaxed variants for xchg Date: Tue, 15 Dec 2015 22:24:16 +0800 Message-Id: <1450189457-10589-4-git-send-email-boqun.feng@gmail.com> X-Mailer: git-send-email 2.6.4 In-Reply-To: <1450189457-10589-1-git-send-email-boqun.feng@gmail.com> References: <1450189457-10589-1-git-send-email-boqun.feng@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6019 Lines: 207 Implement xchg{,64}_relaxed and atomic{,64}_xchg_relaxed, based on these _relaxed variants, release/acquire variants and fully ordered versions can be built. Note that xchg{,64}_relaxed and atomic_{,64}_xchg_relaxed are not compiler barriers. Signed-off-by: Boqun Feng --- arch/powerpc/include/asm/atomic.h | 2 ++ arch/powerpc/include/asm/cmpxchg.h | 69 +++++++++++++++++--------------------- 2 files changed, 32 insertions(+), 39 deletions(-) diff --git a/arch/powerpc/include/asm/atomic.h b/arch/powerpc/include/asm/atomic.h index aac9e0b..409d3cf 100644 --- a/arch/powerpc/include/asm/atomic.h +++ b/arch/powerpc/include/asm/atomic.h @@ -177,6 +177,7 @@ static __inline__ int atomic_dec_return_relaxed(atomic_t *v) #define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) #define atomic_xchg(v, new) (xchg(&((v)->counter), new)) +#define atomic_xchg_relaxed(v, new) xchg_relaxed(&((v)->counter), (new)) /** * __atomic_add_unless - add unless the number is a given value @@ -444,6 +445,7 @@ static __inline__ long atomic64_dec_if_positive(atomic64_t *v) #define atomic64_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n))) #define atomic64_xchg(v, new) (xchg(&((v)->counter), new)) +#define atomic64_xchg_relaxed(v, new) xchg_relaxed(&((v)->counter), (new)) /** * atomic64_add_unless - add unless the number is a given value diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h index d1a8d93..17c7e14 100644 --- a/arch/powerpc/include/asm/cmpxchg.h +++ b/arch/powerpc/include/asm/cmpxchg.h @@ -9,21 +9,20 @@ /* * Atomic exchange * - * Changes the memory location '*ptr' to be val and returns + * Changes the memory location '*p' to be val and returns * the previous value stored there. */ + static __always_inline unsigned long -__xchg_u32(volatile void *p, unsigned long val) +__xchg_u32_local(volatile void *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( - PPC_ATOMIC_ENTRY_BARRIER "1: lwarx %0,0,%2 \n" PPC405_ERR77(0,%2) " stwcx. %3,0,%2 \n\ bne- 1b" - PPC_ATOMIC_EXIT_BARRIER : "=&r" (prev), "+m" (*(volatile unsigned int *)p) : "r" (p), "r" (val) : "cc", "memory"); @@ -31,42 +30,34 @@ __xchg_u32(volatile void *p, unsigned long val) return prev; } -/* - * Atomic exchange - * - * Changes the memory location '*ptr' to be val and returns - * the previous value stored there. - */ static __always_inline unsigned long -__xchg_u32_local(volatile void *p, unsigned long val) +__xchg_u32_relaxed(u32 *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( -"1: lwarx %0,0,%2 \n" - PPC405_ERR77(0,%2) -" stwcx. %3,0,%2 \n\ - bne- 1b" - : "=&r" (prev), "+m" (*(volatile unsigned int *)p) +"1: lwarx %0,0,%2\n" + PPC405_ERR77(0, %2) +" stwcx. %3,0,%2\n" +" bne- 1b" + : "=&r" (prev), "+m" (*p) : "r" (p), "r" (val) - : "cc", "memory"); + : "cc"); return prev; } #ifdef CONFIG_PPC64 static __always_inline unsigned long -__xchg_u64(volatile void *p, unsigned long val) +__xchg_u64_local(volatile void *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( - PPC_ATOMIC_ENTRY_BARRIER "1: ldarx %0,0,%2 \n" PPC405_ERR77(0,%2) " stdcx. %3,0,%2 \n\ bne- 1b" - PPC_ATOMIC_EXIT_BARRIER : "=&r" (prev), "+m" (*(volatile unsigned long *)p) : "r" (p), "r" (val) : "cc", "memory"); @@ -75,18 +66,18 @@ __xchg_u64(volatile void *p, unsigned long val) } static __always_inline unsigned long -__xchg_u64_local(volatile void *p, unsigned long val) +__xchg_u64_relaxed(u64 *p, unsigned long val) { unsigned long prev; __asm__ __volatile__( -"1: ldarx %0,0,%2 \n" - PPC405_ERR77(0,%2) -" stdcx. %3,0,%2 \n\ - bne- 1b" - : "=&r" (prev), "+m" (*(volatile unsigned long *)p) +"1: ldarx %0,0,%2\n" + PPC405_ERR77(0, %2) +" stdcx. %3,0,%2\n" +" bne- 1b" + : "=&r" (prev), "+m" (*p) : "r" (p), "r" (val) - : "cc", "memory"); + : "cc"); return prev; } @@ -99,14 +90,14 @@ __xchg_u64_local(volatile void *p, unsigned long val) extern void __xchg_called_with_bad_pointer(void); static __always_inline unsigned long -__xchg(volatile void *ptr, unsigned long x, unsigned int size) +__xchg_local(volatile void *ptr, unsigned long x, unsigned int size) { switch (size) { case 4: - return __xchg_u32(ptr, x); + return __xchg_u32_local(ptr, x); #ifdef CONFIG_PPC64 case 8: - return __xchg_u64(ptr, x); + return __xchg_u64_local(ptr, x); #endif } __xchg_called_with_bad_pointer(); @@ -114,25 +105,19 @@ __xchg(volatile void *ptr, unsigned long x, unsigned int size) } static __always_inline unsigned long -__xchg_local(volatile void *ptr, unsigned long x, unsigned int size) +__xchg_relaxed(void *ptr, unsigned long x, unsigned int size) { switch (size) { case 4: - return __xchg_u32_local(ptr, x); + return __xchg_u32_relaxed(ptr, x); #ifdef CONFIG_PPC64 case 8: - return __xchg_u64_local(ptr, x); + return __xchg_u64_relaxed(ptr, x); #endif } __xchg_called_with_bad_pointer(); return x; } -#define xchg(ptr,x) \ - ({ \ - __typeof__(*(ptr)) _x_ = (x); \ - (__typeof__(*(ptr))) __xchg((ptr), (unsigned long)_x_, sizeof(*(ptr))); \ - }) - #define xchg_local(ptr,x) \ ({ \ __typeof__(*(ptr)) _x_ = (x); \ @@ -140,6 +125,12 @@ __xchg_local(volatile void *ptr, unsigned long x, unsigned int size) (unsigned long)_x_, sizeof(*(ptr))); \ }) +#define xchg_relaxed(ptr, x) \ +({ \ + __typeof__(*(ptr)) _x_ = (x); \ + (__typeof__(*(ptr))) __xchg_relaxed((ptr), \ + (unsigned long)_x_, sizeof(*(ptr))); \ +}) /* * Compare and exchange - if *p == old, set it to new, * and return the old value of *p. -- 2.6.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/