From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Fri, 12 Jun 2015 09:04:14 +0000 Subject: Re: [PATCH v4 3/3] video: fbdev: vesafb: use arch_phys_wc_add() Message-Id: <557AA08E.6050606@ti.com> MIME-Version: 1 Content-Type: multipart/mixed; boundary="xp6FBBjTRexLOb0hHjnk0l0MG0AWonsoW" List-Id: References: <1433436288-16792-1-git-send-email-mcgrof@do-not-panic.com> <1433436288-16792-4-git-send-email-mcgrof@do-not-panic.com> In-Reply-To: <1433436288-16792-4-git-send-email-mcgrof@do-not-panic.com> To: "Luis R. Rodriguez" Cc: plagnioj@jcrosoft.com, bp@suse.de, hpa@zytor.com, linux-fbdev@vger.kernel.org, luto@amacapital.net, toshi.kani@hp.com, sbsiddha@gmail.com, mingo@elte.hu, tglx@linutronix.de, jgross@suse.com, daniel.vetter@ffwll.ch, airlied@redhat.com, adaplas@gmail.com, robdclark@gmail.com, jg1.han@samsung.com, wsa@the-dreams.de, linux-kernel@vger.kernel.org, "Luis R. Rodriguez" --xp6FBBjTRexLOb0hHjnk0l0MG0AWonsoW Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 04/06/15 19:44, Luis R. Rodriguez wrote: > From: "Luis R. Rodriguez" >=20 > This driver uses the same area for MTRR as for the ioremap_wc(), if > anything it just uses a smaller size in case MTRR reservation fails. > ioremap_wc() API is already used to take advantage of architecture > write-combining when available. >=20 > 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. >=20 > There are a few motivations for this: >=20 > a) Take advantage of PAT when available >=20 > b) Help bury MTRR code away, MTRR is architecture specific and on > x86 its replaced by PAT >=20 > 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()") >=20 > 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. >=20 > @ mtrr_found @ > expression index, base, size; > @@ >=20 > -index =3D mtrr_add(base, size, MTRR_TYPE_WRCOMB, 1); > +index =3D arch_phys_wc_add(base, size); >=20 > @ mtrr_rm depends on mtrr_found @ > expression mtrr_found.index, mtrr_found.base, mtrr_found.size; > @@ >=20 > -mtrr_del(index, base, size); > +arch_phys_wc_del(index); >=20 > @ mtrr_rm_zero_arg depends on mtrr_found @ > expression mtrr_found.index; > @@ >=20 > -mtrr_del(index, 0, 0); > +arch_phys_wc_del(index); >=20 > @ mtrr_rm_fb_info depends on mtrr_found @ > struct fb_info *info; > expression mtrr_found.index; > @@ >=20 > -mtrr_del(index, info->fix.smem_start, info->fix.smem_len); > +arch_phys_wc_del(index); >=20 > @ ioremap_replace_nocache depends on mtrr_found @ > struct fb_info *info; > expression base, size; > @@ >=20 > -info->screen_base =3D ioremap_nocache(base, size); > +info->screen_base =3D ioremap_wc(base, size); >=20 > @ ioremap_replace_default depends on mtrr_found @ > struct fb_info *info; > expression base, size; > @@ >=20 > -info->screen_base =3D ioremap(base, size); > +info->screen_base =3D ioremap_wc(base, size); >=20 > Generated-by: Coccinelle SmPL > Cc: Toshi Kani > 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: Rob Clark > Cc: Jingoo Han > Cc: Wolfram Sang > Cc: Tomi Valkeinen > Cc: linux-fbdev@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Luis R. Rodriguez > --- > drivers/video/fbdev/vesafb.c | 29 ++++++++--------------------- > 1 file changed, 8 insertions(+), 21 deletions(-) >=20 > diff --git a/drivers/video/fbdev/vesafb.c b/drivers/video/fbdev/vesafb.= c > index 3db3908..528fe91 100644 > --- a/drivers/video/fbdev/vesafb.c > +++ b/drivers/video/fbdev/vesafb.c > @@ -19,10 +19,9 @@ > #include > #include > #include > +#include > =20 > #include