From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Luis R. Rodriguez" Subject: Re: [PATCH v1 04/47] pci: add pci_ioremap_wc_bar() Date: Wed, 25 Mar 2015 21:06:36 +0100 Message-ID: <20150325200636.GC12247__36762.2993457646$1427314110$gmane$org@wotan.suse.de> References: <1426893517-2511-1-git-send-email-mcgrof@do-not-panic.com> <1426893517-2511-5-git-send-email-mcgrof@do-not-panic.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1YarZX-00087V-Qi for xen-devel@lists.xenproject.org; Wed, 25 Mar 2015 20:06:39 +0000 Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andy Lutomirski Cc: Juergen Gross , Linux Fbdev development list , X86 ML , Suresh Siddha , Antonino Daplas , "Luis R. Rodriguez" , Daniel Vetter , Tomi Valkeinen , venkatesh.pallipadi@intel.com, "linux-kernel@vger.kernel.org" , "xen-devel@lists.xenproject.org" , Ingo Molnar , Jan Beulich , "H. Peter Anvin" , Dave Airlie , Thomas Gleixner , Borislav Petkov , Jean-Christophe Plagniol-Villard , Ingo Molnar List-Id: xen-devel@lists.xenproject.org On Fri, Mar 20, 2015 at 04:50:32PM -0700, Andy Lutomirski wrote: > On Fri, Mar 20, 2015 at 4:17 PM, Luis R. Rodriguez > wrote: > > From: "Luis R. Rodriguez" > > > > This lets drivers take advanate of PAT when available. This > > should help with the transition of converting video drivers over > > to ioremap_wc() to help with the goal of eventually using > > _PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on > > ioremap_nocache() (de33c442e) > > > > Cc: Suresh Siddha > > Cc: Venkatesh Pallipadi > > Cc: Ingo Molnar > > Cc: Thomas Gleixner > > Cc: Juergen Gross > > Cc: Daniel Vetter > > Cc: Andy Lutomirski > > Cc: Dave Airlie > > Cc: Antonino Daplas > > Cc: Jean-Christophe Plagniol-Villard > > Cc: Tomi Valkeinen > > Cc: linux-fbdev@vger.kernel.org > > Cc: linux-kernel@vger.kernel.org > > Signed-off-by: Luis R. Rodriguez > > --- > > drivers/pci/pci.c | 14 ++++++++++++++ > > include/linux/pci.h | 1 + > > 2 files changed, 15 insertions(+) > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index 81f06e8..6afd507 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -137,6 +137,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) > > pci_resource_len(pdev, bar)); > > } > > EXPORT_SYMBOL_GPL(pci_ioremap_bar); > > + > > +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar) > > +{ > > + /* > > + * Make sure the BAR is actually a memory resource, not an IO resource > > + */ > > + if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) { > > + WARN_ON(1); > > + return NULL; > > + } > > if (WARN_ON(...))? Sure, they are equivalent however this follows the same exact style as pci_ioremap_bar() so if we change this one might as well change the style of pci_ioremap_bar() as well. Let me know if there is any preference. I personally don't mind the extra line as it shortens the check. Luis