Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752502AbbD3Riw (ORCPT ); Thu, 30 Apr 2015 13:38:52 -0400 Received: from mail-ig0-f176.google.com ([209.85.213.176]:35097 "EHLO mail-ig0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752437AbbD3Rit (ORCPT ); Thu, 30 Apr 2015 13:38:49 -0400 MIME-Version: 1.0 In-Reply-To: <1429647230-16870-1-git-send-email-mcgrof@do-not-panic.com> References: <1429647230-16870-1-git-send-email-mcgrof@do-not-panic.com> From: "Luis R. Rodriguez" Date: Thu, 30 Apr 2015 10:38:27 -0700 X-Google-Sender-Auth: PM2xLThh1qvubyfkgG37ckYevqU Message-ID: Subject: Re: [PATCH v3] staging: sm750fb: use arch_phys_wc_add() and ioremap_wc() To: arnaud.patard@rtp-net.org, aaro.koskinen@iki.fi, Greg Kroah-Hartman Cc: "devel@driverdev.osuosl.org" , Andy Lutomirski , "cocci@systeme.lip6.fr" , "Luis R. Rodriguez" , Sudip Mukherjee , Teddy Wang , Suresh Siddha , Ingo Molnar , Thomas Gleixner , Juergen Gross , Daniel Vetter , Dave Airlie , Antonino Daplas , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , linux-fbdev , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3431 Lines: 103 On Tue, Apr 21, 2015 at 1:13 PM, Luis R. Rodriguez wrote: > From: "Luis R. Rodriguez" > > The same area used for ioremap() is used for the MTRR area. > Convert the driver from using the x86 specific MTRR code to > the architecture agnostic arch_phys_wc_add(). arch_phys_wc_add() > will avoid MTRR if write-combining is available, in order to > take advantage of that also ensure the ioremap'd area is requested > as write-combining. > > There are a few motivations for this: > > a) Take advantage of PAT when available > > b) Help bury MTRR code away, MTRR is architecture specific and on > x86 its replaced by PAT > > c) Help with the goal of eventually using _PAGE_CACHE_UC over > _PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache() (see commit > de33c442e titled "x86 PAT: fix performance drop for glx, > use UC minus for ioremap(), ioremap_nocache() and > pci_mmap_page_range()") > > The conversion done is expressed by the following Coccinelle > SmPL patch, it additionally required manual intervention to > address all the #ifdery and removal of redundant things which > arch_phys_wc_add() already addresses such as verbose message > about when MTRR fails and doing nothing when we didn't get > an MTRR. > > @ mtrr_found @ > expression index, base, size; > @@ > > -index = mtrr_add(base, size, MTRR_TYPE_WRCOMB, 1); > +index = arch_phys_wc_add(base, size); > > @ mtrr_rm depends on mtrr_found @ > expression mtrr_found.index, mtrr_found.base, mtrr_found.size; > @@ > > -mtrr_del(index, base, size); > +arch_phys_wc_del(index); > > @ mtrr_rm_zero_arg depends on mtrr_found @ > expression mtrr_found.index; > @@ > > -mtrr_del(index, 0, 0); > +arch_phys_wc_del(index); > > @ mtrr_rm_fb_info depends on mtrr_found @ > struct fb_info *info; > expression mtrr_found.index; > @@ > > -mtrr_del(index, info->fix.smem_start, info->fix.smem_len); > +arch_phys_wc_del(index); > > @ ioremap_replace_nocache depends on mtrr_found @ > struct fb_info *info; > expression base, size; > @@ > > -info->screen_base = ioremap_nocache(base, size); > +info->screen_base = ioremap_wc(base, size); > > @ ioremap_replace_default depends on mtrr_found @ > struct fb_info *info; > expression base, size; > @@ > > -info->screen_base = ioremap(base, size); > +info->screen_base = ioremap_wc(base, size); > > Generated-by: Coccinelle SmPL > Cc: Sudip Mukherjee > Cc: Teddy Wang > Cc: Greg Kroah-Hartman > Cc: Suresh Siddha > 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: devel@driverdev.osuosl.org > Cc: linux-fbdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Luis R. Rodriguez Hey folks, just a follow up. Can this be considered to be merged? Luis -- 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/