From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Tue, 9 Feb 2016 12:36:24 +0100 Subject: [PATCH] ARM: ks8695: fix __initdata annotation In-Reply-To: <18237653.x9qPaNvtCU@wuerfel> References: <1454941509-2773774-1-git-send-email-arnd@arndb.de> <20160209090030.GS13664@pengutronix.de> <18237653.x9qPaNvtCU@wuerfel> Message-ID: <20160209113624.GU13664@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Arnd, On Tue, Feb 09, 2016 at 12:14:15PM +0100, Arnd Bergmann wrote: > On Tuesday 09 February 2016 10:00:30 Uwe Kleine-K?nig wrote: > > > diff --git a/arch/arm/mach-ks8695/board-og.c b/arch/arm/mach-ks8695/board-og.c > > > index 1f4f2f4f25bb..fa1a7c2ca2bb 100644 > > > --- a/arch/arm/mach-ks8695/board-og.c > > > +++ b/arch/arm/mach-ks8695/board-og.c > > > @@ -80,7 +80,7 @@ static void __init og_pci_bus_reset(void) > > > #define S8250_VIRT 0xf4000000 > > > #define S8250_SIZE 0x00100000 > > > > > > -static struct __initdata map_desc og_io_desc[] = { > > > +static struct map_desc __initdata og_io_desc[] = { > > > > I would have expected that > > > > +static struct map_desc og_io_desc[] __initdata = { > > > > is the correct variant? > > > > I think those two mean the exact same thing, and we have tons of examples > for either one in the kernel, unlike the one I removed. I have > verified that the resulting object files are identical. > > Can you point me to some documentation that clarifies which one to use, > and why? Having the attribute list after the declarator isn't recommended as explicit as I remember having read it somewhere in the gcc docs. info gcc "Attribute Syntax" has: An attribute specifier list may appear immediately before a declarator (other than the first) in a comma-separated list of declarators in a declaration of more than one identifier using a single list of specifiers and qualifiers. Such attribute specifiers apply only to the identifier before whose declarator they appear. For example, in __attribute__((noreturn)) void d0 (void), __attribute__((format(printf, 1, 2))) d1 (const char *, ...), d2 (void) the 'noreturn' attribute applies to all the functions declared; the 'format' attribute only applies to 'd1'. (Funny enough, in the example the attribute specifier list doesn't appear *immediately* before the declarator d0.) This might be interpreted as "usually the attribute specifier list appears after the declarator". Other than that I cannot find an explict recommended placement in the docs. The examples in info gcc "Variable Attributes" always have the attribute list after the declarator. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ | From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755967AbcBILg2 (ORCPT ); Tue, 9 Feb 2016 06:36:28 -0500 Received: from metis.ext.4.pengutronix.de ([92.198.50.35]:34137 "EHLO metis.ext.4.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755588AbcBILg0 (ORCPT ); Tue, 9 Feb 2016 06:36:26 -0500 Date: Tue, 9 Feb 2016 12:36:24 +0100 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Arnd Bergmann Cc: Greg Ungerer , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM: ks8695: fix __initdata annotation Message-ID: <20160209113624.GU13664@pengutronix.de> References: <1454941509-2773774-1-git-send-email-arnd@arndb.de> <20160209090030.GS13664@pengutronix.de> <18237653.x9qPaNvtCU@wuerfel> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <18237653.x9qPaNvtCU@wuerfel> User-Agent: Mutt/1.5.23 (2014-03-12) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Arnd, On Tue, Feb 09, 2016 at 12:14:15PM +0100, Arnd Bergmann wrote: > On Tuesday 09 February 2016 10:00:30 Uwe Kleine-König wrote: > > > diff --git a/arch/arm/mach-ks8695/board-og.c b/arch/arm/mach-ks8695/board-og.c > > > index 1f4f2f4f25bb..fa1a7c2ca2bb 100644 > > > --- a/arch/arm/mach-ks8695/board-og.c > > > +++ b/arch/arm/mach-ks8695/board-og.c > > > @@ -80,7 +80,7 @@ static void __init og_pci_bus_reset(void) > > > #define S8250_VIRT 0xf4000000 > > > #define S8250_SIZE 0x00100000 > > > > > > -static struct __initdata map_desc og_io_desc[] = { > > > +static struct map_desc __initdata og_io_desc[] = { > > > > I would have expected that > > > > +static struct map_desc og_io_desc[] __initdata = { > > > > is the correct variant? > > > > I think those two mean the exact same thing, and we have tons of examples > for either one in the kernel, unlike the one I removed. I have > verified that the resulting object files are identical. > > Can you point me to some documentation that clarifies which one to use, > and why? Having the attribute list after the declarator isn't recommended as explicit as I remember having read it somewhere in the gcc docs. info gcc "Attribute Syntax" has: An attribute specifier list may appear immediately before a declarator (other than the first) in a comma-separated list of declarators in a declaration of more than one identifier using a single list of specifiers and qualifiers. Such attribute specifiers apply only to the identifier before whose declarator they appear. For example, in __attribute__((noreturn)) void d0 (void), __attribute__((format(printf, 1, 2))) d1 (const char *, ...), d2 (void) the 'noreturn' attribute applies to all the functions declared; the 'format' attribute only applies to 'd1'. (Funny enough, in the example the attribute specifier list doesn't appear *immediately* before the declarator d0.) This might be interpreted as "usually the attribute specifier list appears after the declarator". Other than that I cannot find an explict recommended placement in the docs. The examples in info gcc "Variable Attributes" always have the attribute list after the declarator. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ |