Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752114AbaKCWyP (ORCPT ); Mon, 3 Nov 2014 17:54:15 -0500 Received: from www.linutronix.de ([62.245.132.108]:55857 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbaKCWyO (ORCPT ); Mon, 3 Nov 2014 17:54:14 -0500 Date: Mon, 3 Nov 2014 23:53:59 +0100 (CET) From: Thomas Gleixner To: Toshi Kani cc: "Elliott, Robert (Server Storage)" , "hpa@zytor.com" , "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" Subject: Re: [PATCH v4 4/7] x86, mm, pat: Add pgprot_writethrough() for WT In-Reply-To: <1415052905.10958.39.camel@misato.fc.hp.com> Message-ID: 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> <1415052905.10958.39.camel@misato.fc.hp.com> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 3 Nov 2014, Toshi Kani wrote: > 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. NAK. This is new functionality and we really have no reason to give the GPL circumventors access to it. Thanks, tglx -- 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/