• Luis R. Rodriguez's avatar
    drivers/video/fbdev/kyrofb: Use arch_phys_wc_add() and pci_ioremap_wc_bar() · 9e517ac8
    Luis R. Rodriguez authored
    Convert the driver from using the x86-specific MTRR code to the
    architecture-agnostic arch_phys_wc_add(). It will avoid MTRR if
    write-combining is available, in order to take advantage of that
    also ensure the ioremapped 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 it is being 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
       de33c442 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 ifdeffery 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);
    Signed-off-by: 's avatarLuis R. Rodriguez <mcgrof@suse.com>
    Signed-off-by: 's avatarBorislav Petkov <bp@suse.de>
    Acked-by: 's avatarTomi Valkeinen <tomi.valkeinen@ti.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Cc: Andy Lutomirski <luto@amacapital.net>
    Cc: Antonino Daplas <adaplas@gmail.com>
    Cc: Arnd Bergmann <arnd@arndb.de>
    Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
    Cc: Dave Airlie <airlied@redhat.com>
    Cc: Geert Uytterhoeven <geert@linux-m68k.org>
    Cc: H. Peter Anvin <hpa@zytor.com>
    Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
    Cc: Jingoo Han <jg1.han@samsung.com>
    Cc: Juergen Gross <jgross@suse.com>
    Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Suresh Siddha <sbsiddha@gmail.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: airlied@linux.ie
    Cc: benh@kernel.crashing.org
    Cc: bhelgaas@google.com
    Cc: dan.j.williams@intel.com
    Cc: konrad.wilk@oracle.com
    Cc: linux-fbdev@vger.kernel.org
    Cc: linux-pci@vger.kernel.org
    Cc: mst@redhat.com
    Cc: toshi.kani@hp.com
    Cc: vinod.koul@intel.com
    Cc: xen-devel@lists.xensource.com
    Link: http://lkml.kernel.org/r/1440443613-13696-4-git-send-email-mcgrof@do-not-panic.comSigned-off-by: 's avatarIngo Molnar <mingo@kernel.org>
    9e517ac8
kyro.h 2.36 KB