Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751587AbaKCW3J (ORCPT ); Mon, 3 Nov 2014 17:29:09 -0500 Received: from g4t3427.houston.hp.com ([15.201.208.55]:35362 "EHLO g4t3427.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751237AbaKCW3G (ORCPT ); Mon, 3 Nov 2014 17:29:06 -0500 Message-ID: <1415052905.10958.39.camel@misato.fc.hp.com> Subject: Re: [PATCH v4 4/7] x86, mm, pat: Add pgprot_writethrough() for WT From: Toshi Kani To: "Elliott, Robert (Server Storage)" Cc: "hpa@zytor.com" , "tglx@linutronix.de" , "mingo@redhat.com" , "akpm@linux-foundation.org" , "arnd@arndb.de" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "jgross@suse.com" , "stefan.bader@canonical.com" , "luto@amacapital.net" , "hmh@hmh.eng.br" , "yigal@plexistor.com" , "konrad.wilk@oracle.com" Date: Mon, 03 Nov 2014 15:15:05 -0700 In-Reply-To: <94D0CD8314A33A4D9D801C0FE68B4029593578ED@G9W0745.americas.hpqcorp.net> References: <1414450545-14028-1-git-send-email-toshi.kani@hp.com> <1414450545-14028-5-git-send-email-toshi.kani@hp.com> <94D0CD8314A33A4D9D801C0FE68B4029593578ED@G9W0745.americas.hpqcorp.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4 (3.10.4-4.fc20) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2014-11-03 at 22:10 +0000, Elliott, Robert (Server Storage) wrote: : > > Subject: [PATCH v4 4/7] x86, mm, pat: Add pgprot_writethrough() for > > WT > > > > This patch adds pgprot_writethrough() for setting WT to a given > > pgprot_t. > > > > Signed-off-by: Toshi Kani > > Reviewed-by: Konrad Rzeszutek Wilk > ... > > diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c > > index a214f5a..a0264d3 100644 > > --- a/arch/x86/mm/pat.c > > +++ b/arch/x86/mm/pat.c > > @@ -896,6 +896,16 @@ pgprot_t pgprot_writecombine(pgprot_t prot) > > } > > EXPORT_SYMBOL_GPL(pgprot_writecombine); > > > > +pgprot_t pgprot_writethrough(pgprot_t prot) > > +{ > > + if (pat_enabled) > > + return __pgprot(pgprot_val(prot) | > > + cachemode2protval(_PAGE_CACHE_MODE_WT)); > > + else > > + return pgprot_noncached(prot); > > +} > > +EXPORT_SYMBOL_GPL(pgprot_writethrough); > ... > > Would you be willing to use EXPORT_SYMBOL for the new > pgprot_writethrough function to provide more flexibility > for modules to utilize the new feature? In x86/mm, 18 of 60 > current exports are GPL and 42 are not GPL. I simply used EXPORT_SYMBOL_GPL() since pgprot_writecombine() used it. :-) This interface is intended to be used along with remap_pfn_range() and ioremap_prot(), which are both exported with EXPORT_SYMBOL(). So, it seems reasonable to export it with EXPORT_SYMBOL() as well. I will make this change. Thanks, -Toshi -- 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/