Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267633AbUIJDYs (ORCPT ); Thu, 9 Sep 2004 23:24:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267649AbUIJDYs (ORCPT ); Thu, 9 Sep 2004 23:24:48 -0400 Received: from TYO201.gate.nec.co.jp ([202.32.8.214]:43650 "EHLO tyo201.gate.nec.co.jp") by vger.kernel.org with ESMTP id S267633AbUIJDYo (ORCPT ); Thu, 9 Sep 2004 23:24:44 -0400 Date: Fri, 10 Sep 2004 12:26:54 +0900 (JST) Message-Id: <200409100326.i8A3QsYV007096@mailsv.bs1.fc.nec.co.jp> To: akpm@osdl.org, hugh@veritas.com, ak@muc.de Cc: wli@holomorphy.com, takata.hirokazu@renesas.com, kaigai@ak.jp.nec.com, linux-kernel@vger.kernel.org Subject: [PATCH] atomic_inc_return() for i386[1/5] (Re: atomic_inc_return) In-Reply-To: Your message of "Thu, 9 Sep 2004 20:48:27 +0100 (BST)". From: kaigai@ak.jp.nec.com (Kaigai Kohei) X-Mailer: mnews [version 1.22PL1] 2000-02/15(Tue) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2263 Lines: 79 [1/5] atomic_inc_return-linux-2.6.9-rc1.i386.patch This patch implements atomic_inc_return() and so on for i386, and includes runtime check whether CPU is legacy 386. It is same as I posted to LKML and Andi Kleen at '04/09/01. Signed-off-by: KaiGai, Kohei -------- Kai Gai diff -rNU4 linux-2.6.9-rc1/include/asm-i386/atomic.h linux-2.6.9-rc1.atomic_inc_return/include/asm-i386/atomic.h --- linux-2.6.9-rc1/include/asm-i386/atomic.h 2004-08-24 16:02:24.000000000 +0900 +++ linux-2.6.9-rc1.atomic_inc_return/include/asm-i386/atomic.h 2004-09-10 10:15:18.000000000 +0900 @@ -1,8 +1,10 @@ #ifndef __ARCH_I386_ATOMIC__ #define __ARCH_I386_ATOMIC__ #include +#include +#include /* * Atomic operations that C can't guarantee us. Useful for * resource counting etc.. @@ -175,8 +177,48 @@ :"ir" (i), "m" (v->counter) : "memory"); return c; } +/** + * atomic_add_return - add and return + * @v: pointer of type atomic_t + * @i: integer value to add + * + * Atomically adds @i to @v and returns @i + @v + */ +static __inline__ int atomic_add_return(int i, atomic_t *v) +{ + int __i; +#ifdef CONFIG_M386 + if(unlikely(boot_cpu_data.x86==3)) + goto no_xadd; +#endif + /* Modern 486+ processor */ + __i = i; + __asm__ __volatile__( + LOCK "xaddl %0, %1;" + :"=r"(i) + :"m"(v->counter), "0"(i)); + return i + __i; + +#ifdef CONFIG_M386 +no_xadd: /* Legacy 386 processor */ + local_irq_disable(); + __i = atomic_read(v); + atomic_set(v, i + __i); + local_irq_enable(); + return i + __i; +#endif +} + +static __inline__ int atomic_sub_return(int i, atomic_t *v) +{ + return atomic_add_return(-i,v); +} + +#define atomic_inc_return(v) (atomic_add_return(1,v)) +#define atomic_dec_return(v) (atomic_sub_return(1,v)) + /* These are x86-specific, used by some header files */ #define atomic_clear_mask(mask, addr) \ __asm__ __volatile__(LOCK "andl %0,%1" \ : : "r" (~(mask)),"m" (*addr) : "memory") - 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/