From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 19DA7C433ED for ; Mon, 10 May 2021 09:40:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAA2D6144F for ; Mon, 10 May 2021 09:40:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230431AbhEJJl5 (ORCPT ); Mon, 10 May 2021 05:41:57 -0400 Received: from foss.arm.com ([217.140.110.172]:51108 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230229AbhEJJl4 (ORCPT ); Mon, 10 May 2021 05:41:56 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 61E151509; Mon, 10 May 2021 02:40:52 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 381F03F73B; Mon, 10 May 2021 02:40:48 -0700 (PDT) From: Mark Rutland To: linux-kernel@vger.kernel.org, will@kernel.org, boqun.feng@gmail.com, peterz@infradead.org Cc: aou@eecs.berkeley.edu, arnd@arndb.de, bcain@codeaurora.org, benh@kernel.crashing.org, chris@zankel.net, dalias@libc.org, davem@davemloft.net, deanbo422@gmail.com, deller@gmx.de, geert@linux-m68k.org, green.hu@gmail.com, guoren@kernel.org, ink@jurassic.park.msu.ru, James.Bottomley@HansenPartnership.com, jcmvbkbc@gmail.com, jonas@southpole.se, ley.foon.tan@intel.com, linux@armlinux.org.uk, mark.rutland@arm.com, mattst88@gmail.com, monstr@monstr.eu, mpe@ellerman.id.au, nickhu@andestech.com, palmer@dabbelt.com, paulus@samba.org, paul.walmsley@sifive.com, rth@twiddle.net, shorne@gmail.com, stefan.kristiansson@saunalahti.fi, tsbogend@alpha.franken.de, vgupta@synopsys.com, ysato@users.sourceforge.jp Subject: [PATCH 12/33] locking/atomic: cmpxchg: support ARCH_ATOMIC Date: Mon, 10 May 2021 10:37:32 +0100 Message-Id: <20210510093753.40683-13-mark.rutland@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20210510093753.40683-1-mark.rutland@arm.com> References: <20210510093753.40683-1-mark.rutland@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We'd like all architectures to convert to ARCH_ATOMIC, as this will enable functionality, and once all architectures are converted it will be possible to make significant cleanups to the atomic headers. A number of architectures use asm-generic/cmpxchg.h or asm-generic/cmpxhg-local.h, and it's impractical to convert the headers and all these architectures in one go. To make it possible to convert them one-by-one, let's make the asm-generic implementation function as either cmpxchg*() or arch_cmpxchg*() depending on whether ARCH_ATOMIC is selected. To do this, the generic implementations are prefixed as generic_cmpxchg_*(), and preprocessor definitions map cmpxchg_*()/arch_cmpxchg_*() onto these as appropriate. Once all users are moved over to ARCH_ATOMIC the ifdeffery in the header can be simplified and/or removed entirely. For existing users (none of which select ARCH_ATOMIC), there should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Arnd Bergmann Cc: Boqun Feng Cc: Peter Zijlstra Cc: Will Deacon --- include/asm-generic/cmpxchg.h | 61 +++++++++++++++++++++++++++++++------------ 1 file changed, 44 insertions(+), 17 deletions(-) diff --git a/include/asm-generic/cmpxchg.h b/include/asm-generic/cmpxchg.h index b9d54c7afc52..98c931199089 100644 --- a/include/asm-generic/cmpxchg.h +++ b/include/asm-generic/cmpxchg.h @@ -14,16 +14,14 @@ #include #include -#ifndef xchg - /* * This function doesn't exist, so you'll get a linker error if * something tries to do an invalidly-sized xchg(). */ -extern void __xchg_called_with_bad_pointer(void); +extern void __generic_xchg_called_with_bad_pointer(void); static inline -unsigned long __xchg(unsigned long x, volatile void *ptr, int size) +unsigned long __generic_xchg(unsigned long x, volatile void *ptr, int size) { unsigned long ret, flags; @@ -75,35 +73,64 @@ unsigned long __xchg(unsigned long x, volatile void *ptr, int size) #endif /* CONFIG_64BIT */ default: - __xchg_called_with_bad_pointer(); + __generic_xchg_called_with_bad_pointer(); return x; } } -#define xchg(ptr, x) ({ \ - ((__typeof__(*(ptr))) \ - __xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))); \ +#define generic_xchg(ptr, x) ({ \ + ((__typeof__(*(ptr))) \ + __generic_xchg((unsigned long)(x), (ptr), sizeof(*(ptr)))); \ }) -#endif /* xchg */ - /* * Atomic compare and exchange. */ #include -#ifndef cmpxchg_local -#define cmpxchg_local(ptr, o, n) ({ \ - ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o),\ - (unsigned long)(n), sizeof(*(ptr)))); \ +#define generic_cmpxchg_local(ptr, o, n) ({ \ + ((__typeof__(*(ptr)))__generic_cmpxchg_local((ptr), (unsigned long)(o), \ + (unsigned long)(n), sizeof(*(ptr)))); \ }) + +#define generic_cmpxchg64_local(ptr, o, n) \ + __generic_cmpxchg64_local((ptr), (o), (n)) + + +#ifdef CONFIG_ARCH_ATOMIC + +#ifndef arch_xchg +#define arch_xchg generic_xchg +#endif + +#ifndef arch_cmpxchg_local +#define arch_cmpxchg_local generic_cmpxchg_local +#endif + +#ifndef arch_cmpxchg64_local +#define arch_cmpxchg64_local generic_cmpxchg64_local +#endif + +#define arch_cmpxchg arch_cmpxchg_local +#define arch_cmpxchg64 arch_cmpxchg64_local + +#else /* CONFIG_ARCH_ATOMIC */ + +#ifndef xchg +#define xchg generic_xchg +#endif + +#ifndef cmpxchg_local +#define cmpxchg_local generic_cmpxchg_local #endif #ifndef cmpxchg64_local -#define cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n)) +#define cmpxchg64_local generic_cmpxchg64_local #endif -#define cmpxchg(ptr, o, n) cmpxchg_local((ptr), (o), (n)) -#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n)) +#define cmpxchg cmpxchg_local +#define cmpxchg64 cmpxchg64_local + +#endif /* CONFIG_ARCH_ATOMIC */ #endif /* __ASM_GENERIC_CMPXCHG_H */ -- 2.11.0