Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752007AbbEEAOV (ORCPT ); Mon, 4 May 2015 20:14:21 -0400 Received: from cantor2.suse.de ([195.135.220.15]:55113 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751270AbbEEAOJ (ORCPT ); Mon, 4 May 2015 20:14:09 -0400 Date: Tue, 5 May 2015 02:14:04 +0200 From: "Luis R. Rodriguez" To: Greg KH Cc: "Luis R. Rodriguez" , sudipm.mukherjee@gmail.com, teddy.wang@siliconmotion.com, devel@driverdev.osuosl.org, luto@amacapital.net, cocci@systeme.lip6.fr, Suresh Siddha , Ingo Molnar , Thomas Gleixner , Juergen Gross , Daniel Vetter , Dave Airlie , Antonino Daplas , Jean-Christophe Plagniol-Villard , Tomi Valkeinen , linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] staging: sm750fb: use arch_phys_wc_add() and ioremap_wc() Message-ID: <20150505001404.GD5622@wotan.suse.de> References: <1429647123-16777-1-git-send-email-mcgrof@do-not-panic.com> <20150503192459.GA19486@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150503192459.GA19486@kroah.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3932 Lines: 110 On Sun, May 03, 2015 at 09:24:59PM +0200, Greg KH wrote: > On Tue, Apr 21, 2015 at 01:12:03PM -0700, 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 > > --- > > drivers/staging/sm750fb/sm750.c | 36 ++++-------------------------------- > > drivers/staging/sm750fb/sm750.h | 3 --- > > drivers/staging/sm750fb/sm750_hw.c | 3 +-- > > 3 files changed, 5 insertions(+), 37 deletions(-) > > This doesn't apply to my staging-next branch :( OK I'll resend a v4 now. 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/