On Thu, Apr 30, 2015 at 10:38:27AM -0700, Luis R. Rodriguez wrote: > On Tue, Apr 21, 2015 at 1:13 PM, Luis R. Rodriguez > <mcgrof@xxxxxxxxxxxxxxxx> wrote: > > From: "Luis R. Rodriguez" <mcgrof@xxxxxxxx> > > > > 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 <sudipm.mukherjee@xxxxxxxxx> > > Cc: Teddy Wang <teddy.wang@xxxxxxxxxxxxxxxxx> > > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > Cc: Suresh Siddha <sbsiddha@xxxxxxxxx> > > Cc: Ingo Molnar <mingo@xxxxxxx> > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Cc: Juergen Gross <jgross@xxxxxxxx> > > Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> > > Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx> > > Cc: Dave Airlie <airlied@xxxxxxxxxx> > > Cc: Antonino Daplas <adaplas@xxxxxxxxx> > > Cc: Jean-Christophe Plagniol-Villard <plagnioj@xxxxxxxxxxxx> > > Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx> > > Cc: devel@xxxxxxxxxxxxxxxxxxxx > > Cc: linux-fbdev@xxxxxxxxxxxxxxx > > Cc: linux-kernel@xxxxxxxxxxxxxxx > > Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxx> > > Hey folks, just a follow up. Can this be considered to be merged? > > Luis I'm just starting to get to staging tree patches after the -rc1 window was over. Give me a week or so, they are at the bottom of my list. thanks, greg k-h _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
