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[PATCH v4 00/11] x86/dma: RIP MTRR and dma write-combine API rename

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  [PATCH v4 00/11] x86/dma: RIP MTRR and dma write-combine API rename "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:20 +0200
    [PATCH v4 01/11] PCI: Add pci_ioremap_wc_bar() "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:20 +0200
      [tip:x86/mm] PCI: Add pci_ioremap_wc_bar() "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 02/11] drivers/video/fbdev/i740fb: Use arch_phys_wc_add() and pci_ioremap_wc_bar() "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:20 +0200
      [tip:x86/mm] drivers/video/fbdev/i740fb: Use arch_phys_wc_add()   and pci_ioremap_wc_bar() "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 03/11] drivers/video/fbdev/kyrofb: Use arch_phys_wc_add() and pci_ioremap_wc_bar() "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] drivers/video/fbdev/kyrofb: Use arch_phys_wc_add()   and pci_ioremap_wc_bar() "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 05/11] PCI: Add pci_iomap_wc() variants "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] PCI: Add pci_iomap_wc() variants "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 08/11] drivers/video/fbdev/vt8623fb: Use arch_phys_wc_add() and pci_iomap_wc() "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] drivers/video/fbdev/vt8623fb: Use arch_phys_wc_add()   and pci_iomap_wc() "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 11/11] mtrr: bury MTRR - unexport mtrr_add() and mtrr_del() "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] x86/mm/mtrr: Remove kernel internal MTRR interfaces:   unexport mtrr_add() and mtrr_del() "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-28 10:20 +0200
    [PATCH v4 09/11] drivers/dma/iop-adma: Use dma_alloc_writecombine() kernel-style "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] drivers/dma/iop-adma: Use dma_alloc_writecombine()   kernel-style "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 04/11] drivers/video/fbdev/gxt4500: Use pci_ioremap_wc_bar() to map framebuffer "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] drivers/video/fbdev/gxt4500: Use pci_ioremap_wc_bar(  ) to map framebuffer "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 07/11] drivers/video/fbdev/s3fb: Use arch_phys_wc_add() and pci_iomap_wc() "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] drivers/video/fbdev/s3fb: Use arch_phys_wc_add()   and pci_iomap_wc() "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    [PATCH v4 06/11] drivers/video/fbdev/arkfb.c: Use arch_phys_wc_add() and pci_iomap_wc() "Luis R. Rodriguez" <mcgrof@do-not-panic.com> - 2015-08-24 21:30 +0200
      [tip:x86/mm] drivers/video/fbdev/arkfb.c: Use arch_phys_wc_add()   and pci_iomap_wc() "tip-bot for Luis R. Rodriguez" <tipbot@zytor.com> - 2015-08-25 10:30 +0200
    Re: [PATCH v4 10/11] dma: rename dma_*_writecombine() to dma_*_wc() Ingo Molnar <mingo@kernel.org> - 2015-08-25 10:20 +0200
      Re: [PATCH v4 10/11] dma: rename dma_*_writecombine() to dma_*_wc() "Luis R. Rodriguez" <mcgrof@suse.com> - 2015-08-25 17:50 +0200
        Re: [PATCH v4 10/11] dma: rename dma_*_writecombine() to dma_*_wc() Andrew Morton <akpm@linux-foundation.org> - 2015-08-25 22:50 +0200
          Re: [PATCH v4 10/11] dma: rename dma_*_writecombine() to dma_*_wc() "Luis R. Rodriguez" <mcgrof@suse.com> - 2015-08-26 01:20 +0200
            Re: [PATCH v4 10/11] dma: rename dma_*_writecombine() to dma_*_wc() Andrew Morton <akpm@linux-foundation.org> - 2015-08-26 01:30 +0200
              Re: [PATCH v4 10/11] dma: rename dma_*_writecombine() to dma_*_wc() Ingo Molnar <mingo@kernel.org> - 2015-08-26 06:30 +0200

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#1212436 — [PATCH v4 00/11] x86/dma: RIP MTRR and dma write-combine API rename

From: "Luis R. Rodriguez" <mcgrof@suse.com>

Ingo,

This is my pending series of patches for both write-combining and moving
Linux' use of MTRR into the grave. It combines three set of straggler patch
series which have been pending integration for a while now. The rename patches
do not depend in any way with the MTRR patches but I've combined them here as
they are all pending and relating to write-combining. I explain why integration
of such patches has been delayed but also provide reasoning for why I believe
its time to merge them.

1) The DMA API rename for write-combining goes with the old naming convention
   defines added as suggested by you for any possible stragglers which may come
   up as this goes through and gets merged. We can remove the old define
   mappings after a release once this gets sucked in and things settle. These
   patches have been in Boris tree for a while but I keep having to refresh
   them as the kernel moves on, the addition of the old mapping should allow
   us to merge this without any collateral.

2) The PCI driver changes go with Tomi Valkeinen's Acks as well as
   Arnd Bergmann's own Acks for the PCI and asm-generic changes. This series
   was technically acknowledged by Bjorn to be correct and acceptable but his
   preference was for this to not use EXPORT_SYMBOL_GPL() as not *all*
   write-combine APIs are using EXPORT_SYMBOL_GPL(). Our goal on x86 though
   is to not deal with bug reports for new PAT APIs [0] and since its now clear
   through documentation that its up to the maintainers / developers if they
   decide to use EXPORT_SYMBOL_GPL() for new *features* [1] I keep that
   practice in alignment with our own x86 goals to avoid bug reports and
   issues with proprietary drivers on new PAT interfaces. Bjorn was happy for
   this to go through someone else's tree, in particular Arnd's. Arnd Acked
   the series [2] but is unable to take these patches in at this time as he's
   out on paternal leave so sending these through you with the respective Acks.
   Boris has been hugely instrumental on helping review all MTRR related 
   series, these were sitting on his queue for a while, but he's also
   unavailable now as he's on vacation.

3) Unexporting direct MTRR access. This is last patch, I had posted this first
   on March 2015 when [3] I originally had meshed up all the MTRR work into one
   giant series. I ending up splitting up all the work into *over* 12 series.
   Now that all the work is merged except these few patches I've combined that
   patch as the last part of this series. I've amended an obituary note for
   MTRR regarding platform firmware access to MTRR based on recent discussions
   [4] and updated the documentation to reflect the status quo for Linux.

All of these patches have been tested by the 0-day bot machine. The only thing
*new* here is just my obituary amended documentation note for platform firmware
access to MTRRs on the last patch based hugely on review with Toshi.

[0] http://lkml.kernel.org/r/1424961893.17007.139.camel@misato.fc.hp.com
[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=582ed8d51e2b6cb8a168c94852bca482685c2509
[2] http://lkml.kernel.org/r/2962702.QXZzP3RbKY@wuerfel
[3] http://lkml.kernel.org/r/1426893517-2511-48-git-send-email-mcgrof@do-not-panic.com
[4] http://lkml.kernel.org/r/1438991330.3109.196.camel@hp.com

Luis R. Rodriguez (11):
  PCI: Add pci_ioremap_wc_bar()
  drivers/video/fbdev/i740fb: Use arch_phys_wc_add() and
    pci_ioremap_wc_bar()
  drivers/video/fbdev/kyrofb: Use arch_phys_wc_add() and
    pci_ioremap_wc_bar()
  drivers/video/fbdev/gxt4500: Use pci_ioremap_wc_bar() to map
    framebuffer
  PCI: Add pci_iomap_wc() variants
  drivers/video/fbdev/arkfb.c: Use arch_phys_wc_add() and pci_iomap_wc()
  drivers/video/fbdev/s3fb: Use arch_phys_wc_add() and pci_iomap_wc()
  drivers/video/fbdev/vt8623fb: Use arch_phys_wc_add() and
    pci_iomap_wc()
  drivers/dma/iop-adma: Use dma_alloc_writecombine() kernel-style
  dma: rename dma_*_writecombine() to dma_*_wc()
  mtrr: bury MTRR - unexport mtrr_add() and mtrr_del()

 Documentation/x86/mtrr.txt                | 20 ++++++++--
 arch/arm/mach-lpc32xx/phy3250.c           | 13 +++---
 arch/arm/mach-netx/fb.c                   | 14 +++----
 arch/arm/mach-nspire/clcd.c               | 13 +++---
 arch/avr32/include/asm/dma-mapping.h      | 20 +++++-----
 arch/avr32/mm/dma-coherent.c              | 12 +++---
 arch/metag/include/asm/dma-mapping.h      |  4 +-
 arch/metag/kernel/dma.c                   |  6 +--
 arch/x86/kernel/cpu/mtrr/main.c           |  2 -
 drivers/dma/iop-adma.c                    |  9 +++--
 drivers/dma/mv_xor.c                      |  4 +-
 drivers/dma/qcom_bam_dma.c                | 14 +++----
 drivers/gpu/drm/drm_gem_cma_helper.c      | 13 +++---
 drivers/gpu/drm/omapdrm/omap_dmm_tiler.c  | 13 +++---
 drivers/gpu/drm/omapdrm/omap_gem.c        |  8 ++--
 drivers/gpu/drm/sti/sti_cursor.c          | 13 +++---
 drivers/gpu/drm/sti/sti_gdp.c             |  3 +-
 drivers/gpu/drm/sti/sti_hqvdp.c           |  6 +--
 drivers/gpu/drm/tegra/gem.c               | 11 +++---
 drivers/gpu/host1x/cdma.c                 |  8 ++--
 drivers/gpu/host1x/job.c                  | 10 ++---
 drivers/media/platform/coda/coda-bit.c    | 10 ++---
 drivers/pci/pci.c                         | 14 +++++++
 drivers/video/fbdev/acornfb.c             |  4 +-
 drivers/video/fbdev/amba-clcd-versatile.c | 14 +++----
 drivers/video/fbdev/amba-clcd.c           |  4 +-
 drivers/video/fbdev/arkfb.c               | 36 +++--------------
 drivers/video/fbdev/atmel_lcdfb.c         |  9 +++--
 drivers/video/fbdev/ep93xx-fb.c           |  9 ++---
 drivers/video/fbdev/gbefb.c               |  8 ++--
 drivers/video/fbdev/gxt4500.c             |  2 +-
 drivers/video/fbdev/i740fb.c              | 35 +++-------------
 drivers/video/fbdev/imxfb.c               | 12 +++---
 drivers/video/fbdev/kyro/fbdev.c          | 33 ++++++----------
 drivers/video/fbdev/mx3fb.c               |  9 ++---
 drivers/video/fbdev/nuc900fb.c            |  8 ++--
 drivers/video/fbdev/omap/lcdc.c           | 16 ++++----
 drivers/video/fbdev/pxa168fb.c            |  8 ++--
 drivers/video/fbdev/pxafb.c               |  4 +-
 drivers/video/fbdev/s3c-fb.c              |  7 ++--
 drivers/video/fbdev/s3c2410fb.c           |  8 ++--
 drivers/video/fbdev/s3fb.c                | 35 +++-------------
 drivers/video/fbdev/sa1100fb.c            |  8 ++--
 drivers/video/fbdev/vt8623fb.c            | 31 +++------------
 include/asm-generic/pci_iomap.h           | 14 +++++++
 include/linux/dma-mapping.h               | 16 ++++----
 include/linux/pci.h                       |  1 +
 include/video/kyro.h                      |  4 +-
 lib/pci_iomap.c                           | 66 +++++++++++++++++++++++++++++++
 sound/arm/pxa2xx-pcm-lib.c                | 20 ++++------
 sound/soc/fsl/imx-pcm-fiq.c               | 10 ++---
 sound/soc/nuc900/nuc900-pcm.c             |  6 +--
 sound/soc/omap/omap-pcm.c                 | 12 ++----
 53 files changed, 331 insertions(+), 358 deletions(-)

-- 
2.4.3

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#1212437 — [PATCH v4 01/11] PCI: Add pci_ioremap_wc_bar()

From: "Luis R. Rodriguez" <mcgrof@suse.com>

This lets drivers take advantage of PAT when available. It should help
with the transition of converting video drivers over to ioremap_wc()
to help with the goal of eventually using _PAGE_CACHE_UC over
_PAGE_CACHE_UC_MINUS on x86 on ioremap_nocache(), see:

  de33c442ed2a ("x86 PAT: fix performance drop for glx, use UC minus for ioremap(),
		ioremap_nocache() and pci_mmap_page_range()")

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: benh@kernel.crashing.org
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: Mel Gorman <mgorman@suse.de>
Cc: mst@redhat.com
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/1435195342-26879-2-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/pci/pci.c   | 14 ++++++++++++++
 include/linux/pci.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8037c27beb05..33867b8a4bc9 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -138,6 +138,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
 	return ioremap_nocache(res->start, resource_size(res));
 }
 EXPORT_SYMBOL_GPL(pci_ioremap_bar);
+
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
+{
+	/*
+	 * Make sure the BAR is actually a memory resource, not an IO resource
+	 */
+	if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
+		WARN_ON(1);
+		return NULL;
+	}
+	return ioremap_wc(pci_resource_start(pdev, bar),
+			  pci_resource_len(pdev, bar));
+}
+EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
 #endif
 
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 88bee285b93d..2b2d7d44c21a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1701,6 +1701,7 @@ static inline void pci_mmcfg_late_init(void) { }
 int pci_ext_cfg_avail(void);
 
 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
 
 #ifdef CONFIG_PCI_IOV
 int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
-- 
2.4.3

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#1212825 — [tip:x86/mm] PCI: Add pci_ioremap_wc_bar()

Commit-ID:  c43996f4001de629af4a4d6713782e883677e5b9
Gitweb:     http://git.kernel.org/tip/c43996f4001de629af4a4d6713782e883677e5b9
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:23 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:43 +0200

PCI: Add pci_ioremap_wc_bar()

This lets drivers take advantage of PAT when available. It
should help with the transition of converting video drivers over
to ioremap_wc() to help with the goal of eventually using
_PAGE_CACHE_UC over _PAGE_CACHE_UC_MINUS on x86 on
ioremap_nocache(), see:

  de33c442ed2a ("x86 PAT: fix performance drop for glx, use UC minus for ioremap(), ioremap_nocache() and pci_mmap_page_range()")

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: <syrjala@sci.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: airlied@linux.ie
Cc: benh@kernel.crashing.org
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: vinod.koul@intel.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1440443613-13696-2-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/pci/pci.c   | 14 ++++++++++++++
 include/linux/pci.h |  1 +
 2 files changed, 15 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 0008c95..fdae37b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -138,6 +138,20 @@ void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar)
 	return ioremap_nocache(res->start, resource_size(res));
 }
 EXPORT_SYMBOL_GPL(pci_ioremap_bar);
+
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar)
+{
+	/*
+	 * Make sure the BAR is actually a memory resource, not an IO resource
+	 */
+	if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) {
+		WARN_ON(1);
+		return NULL;
+	}
+	return ioremap_wc(pci_resource_start(pdev, bar),
+			  pci_resource_len(pdev, bar));
+}
+EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar);
 #endif
 
 #define PCI_FIND_CAP_TTL	48
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 8a0321a..985dd39 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1661,6 +1661,7 @@ static inline void pci_mmcfg_late_init(void) { }
 int pci_ext_cfg_avail(void);
 
 void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
+void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar);
 
 #ifdef CONFIG_PCI_IOV
 int pci_iov_virtfn_bus(struct pci_dev *dev, int id);
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#1212438 — [PATCH v4 02/11] drivers/video/fbdev/i740fb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()

From: "Luis R. Rodriguez" <mcgrof@suse.com>

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
   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
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: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Tomi 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: benh@kernel.crashing.org
Cc: Benoit Taine <benoit.taine@lip6.fr>
Cc: Bjorn Helgaas <bhelgaas@google.com>
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: Ingo Molnar <mingo@kernel.org>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: mst@redhat.com
Cc: Rob Clark <robdclark@gmail.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1435195342-26879-3-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/video/fbdev/i740fb.c | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/drivers/video/fbdev/i740fb.c b/drivers/video/fbdev/i740fb.c
index a2b4204b42bb..452e1163ad02 100644
--- a/drivers/video/fbdev/i740fb.c
+++ b/drivers/video/fbdev/i740fb.c
@@ -27,24 +27,15 @@
 #include <linux/console.h>
 #include <video/vga.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 #include "i740_reg.h"
 
 static char *mode_option;
-
-#ifdef CONFIG_MTRR
 static int mtrr = 1;
-#endif
 
 struct i740fb_par {
 	unsigned char __iomem *regs;
 	bool has_sgram;
-#ifdef CONFIG_MTRR
-	int mtrr_reg;
-#endif
+	int wc_cookie;
 	bool ddc_registered;
 	struct i2c_adapter ddc_adapter;
 	struct i2c_algo_bit_data ddc_algo;
@@ -1040,7 +1031,7 @@ static int i740fb_probe(struct pci_dev *dev, const struct pci_device_id *ent)
 		goto err_request_regions;
 	}
 
-	info->screen_base = pci_ioremap_bar(dev, 0);
+	info->screen_base = pci_ioremap_wc_bar(dev, 0);
 	if (!info->screen_base) {
 		dev_err(info->device, "error remapping base\n");
 		ret = -ENOMEM;
@@ -1144,13 +1135,9 @@ static int i740fb_probe(struct pci_dev *dev, const struct pci_device_id *ent)
 
 	fb_info(info, "%s frame buffer device\n", info->fix.id);
 	pci_set_drvdata(dev, info);
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		par->mtrr_reg = -1;
-		par->mtrr_reg = mtrr_add(info->fix.smem_start,
-				info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
-	}
-#endif
+	if (mtrr)
+		par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+						  info->fix.smem_len);
 	return 0;
 
 err_reg_framebuffer:
@@ -1177,13 +1164,7 @@ static void i740fb_remove(struct pci_dev *dev)
 
 	if (info) {
 		struct i740fb_par *par = info->par;
-
-#ifdef CONFIG_MTRR
-		if (par->mtrr_reg >= 0) {
-			mtrr_del(par->mtrr_reg, 0, 0);
-			par->mtrr_reg = -1;
-		}
-#endif
+		arch_phys_wc_del(par->wc_cookie);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);
 		if (par->ddc_registered)
@@ -1287,10 +1268,8 @@ static int  __init i740fb_setup(char *options)
 	while ((opt = strsep(&options, ",")) != NULL) {
 		if (!*opt)
 			continue;
-#ifdef CONFIG_MTRR
 		else if (!strncmp(opt, "mtrr:", 5))
 			mtrr = simple_strtoul(opt + 5, NULL, 0);
-#endif
 		else
 			mode_option = opt;
 	}
@@ -1327,7 +1306,5 @@ MODULE_DESCRIPTION("fbdev driver for Intel740");
 module_param(mode_option, charp, 0444);
 MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
 
-#ifdef CONFIG_MTRR
 module_param(mtrr, int, 0444);
 MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
-#endif
-- 
2.4.3

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#1212822 — [tip:x86/mm] drivers/video/fbdev/i740fb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()

Commit-ID:  c112709809b2ca1e8ff2841a1958503e548b81e4
Gitweb:     http://git.kernel.org/tip/c112709809b2ca1e8ff2841a1958503e548b81e4
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:24 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:44 +0200

drivers/video/fbdev/i740fb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()

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
   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 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: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tomi 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: Benoit Taine <benoit.taine@lip6.fr>
Cc: Bjorn Helgaas <bhelgaas@google.com>
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: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: benh@kernel.crashing.org
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/1440443613-13696-3-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/video/fbdev/i740fb.c | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/drivers/video/fbdev/i740fb.c b/drivers/video/fbdev/i740fb.c
index a2b4204..452e116 100644
--- a/drivers/video/fbdev/i740fb.c
+++ b/drivers/video/fbdev/i740fb.c
@@ -27,24 +27,15 @@
 #include <linux/console.h>
 #include <video/vga.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 #include "i740_reg.h"
 
 static char *mode_option;
-
-#ifdef CONFIG_MTRR
 static int mtrr = 1;
-#endif
 
 struct i740fb_par {
 	unsigned char __iomem *regs;
 	bool has_sgram;
-#ifdef CONFIG_MTRR
-	int mtrr_reg;
-#endif
+	int wc_cookie;
 	bool ddc_registered;
 	struct i2c_adapter ddc_adapter;
 	struct i2c_algo_bit_data ddc_algo;
@@ -1040,7 +1031,7 @@ static int i740fb_probe(struct pci_dev *dev, const struct pci_device_id *ent)
 		goto err_request_regions;
 	}
 
-	info->screen_base = pci_ioremap_bar(dev, 0);
+	info->screen_base = pci_ioremap_wc_bar(dev, 0);
 	if (!info->screen_base) {
 		dev_err(info->device, "error remapping base\n");
 		ret = -ENOMEM;
@@ -1144,13 +1135,9 @@ static int i740fb_probe(struct pci_dev *dev, const struct pci_device_id *ent)
 
 	fb_info(info, "%s frame buffer device\n", info->fix.id);
 	pci_set_drvdata(dev, info);
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		par->mtrr_reg = -1;
-		par->mtrr_reg = mtrr_add(info->fix.smem_start,
-				info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
-	}
-#endif
+	if (mtrr)
+		par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+						  info->fix.smem_len);
 	return 0;
 
 err_reg_framebuffer:
@@ -1177,13 +1164,7 @@ static void i740fb_remove(struct pci_dev *dev)
 
 	if (info) {
 		struct i740fb_par *par = info->par;
-
-#ifdef CONFIG_MTRR
-		if (par->mtrr_reg >= 0) {
-			mtrr_del(par->mtrr_reg, 0, 0);
-			par->mtrr_reg = -1;
-		}
-#endif
+		arch_phys_wc_del(par->wc_cookie);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);
 		if (par->ddc_registered)
@@ -1287,10 +1268,8 @@ static int  __init i740fb_setup(char *options)
 	while ((opt = strsep(&options, ",")) != NULL) {
 		if (!*opt)
 			continue;
-#ifdef CONFIG_MTRR
 		else if (!strncmp(opt, "mtrr:", 5))
 			mtrr = simple_strtoul(opt + 5, NULL, 0);
-#endif
 		else
 			mode_option = opt;
 	}
@@ -1327,7 +1306,5 @@ MODULE_DESCRIPTION("fbdev driver for Intel740");
 module_param(mode_option, charp, 0444);
 MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
 
-#ifdef CONFIG_MTRR
 module_param(mtrr, int, 0444);
 MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
-#endif
--
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#1212439 — [PATCH v4 03/11] drivers/video/fbdev/kyrofb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()

From: "Luis R. Rodriguez" <mcgrof@suse.com>

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
   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
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: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Tomi 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: benh@kernel.crashing.org
Cc: bhelgaas@google.com
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: Ingo Molnar <mingo@kernel.org>
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: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: mst@redhat.com
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1435195342-26879-4-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/video/fbdev/kyro/fbdev.c | 33 +++++++++++----------------------
 include/video/kyro.h             |  4 +---
 2 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c
index 65041e15fd59..5bb01533271e 100644
--- a/drivers/video/fbdev/kyro/fbdev.c
+++ b/drivers/video/fbdev/kyro/fbdev.c
@@ -22,9 +22,6 @@
 #include <linux/pci.h>
 #include <asm/io.h>
 #include <linux/uaccess.h>
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
 
 #include <video/kyro.h>
 
@@ -84,9 +81,7 @@ static device_info_t deviceInfo;
 static char *mode_option = NULL;
 static int nopan = 0;
 static int nowrap = 1;
-#ifdef CONFIG_MTRR
 static int nomtrr = 0;
-#endif
 
 /* PCI driver prototypes */
 static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
@@ -570,10 +565,8 @@ static int __init kyrofb_setup(char *options)
 			nopan = 1;
 		} else if (strcmp(this_opt, "nowrap") == 0) {
 			nowrap = 1;
-#ifdef CONFIG_MTRR
 		} else if (strcmp(this_opt, "nomtrr") == 0) {
 			nomtrr = 1;
-#endif
 		} else {
 			mode_option = this_opt;
 		}
@@ -691,17 +684,16 @@ static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	currentpar->regbase = deviceInfo.pSTGReg =
 		ioremap_nocache(kyro_fix.mmio_start, kyro_fix.mmio_len);
+	if (!currentpar->regbase)
+		goto out_free_fb;
 
-	info->screen_base = ioremap_nocache(kyro_fix.smem_start,
-					    kyro_fix.smem_len);
+	info->screen_base = pci_ioremap_wc_bar(pdev, 0);
+	if (!info->screen_base)
+		goto out_unmap_regs;
 
-#ifdef CONFIG_MTRR
 	if (!nomtrr)
-		currentpar->mtrr_handle =
-			mtrr_add(kyro_fix.smem_start,
-				 kyro_fix.smem_len,
-				 MTRR_TYPE_WRCOMB, 1);
-#endif
+		currentpar->wc_cookie = arch_phys_wc_add(kyro_fix.smem_start,
+							 kyro_fix.smem_len);
 
 	kyro_fix.ypanstep	= nopan ? 0 : 1;
 	kyro_fix.ywrapstep	= nowrap ? 0 : 1;
@@ -745,8 +737,10 @@ static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	return 0;
 
 out_unmap:
-	iounmap(currentpar->regbase);
 	iounmap(info->screen_base);
+out_unmap_regs:
+	iounmap(currentpar->regbase);
+out_free_fb:
 	framebuffer_release(info);
 
 	return -EINVAL;
@@ -770,12 +764,7 @@ static void kyrofb_remove(struct pci_dev *pdev)
 	iounmap(info->screen_base);
 	iounmap(par->regbase);
 
-#ifdef CONFIG_MTRR
-	if (par->mtrr_handle)
-		mtrr_del(par->mtrr_handle,
-			 info->fix.smem_start,
-			 info->fix.smem_len);
-#endif
+	arch_phys_wc_del(par->wc_cookie);
 
 	unregister_framebuffer(info);
 	framebuffer_release(info);
diff --git a/include/video/kyro.h b/include/video/kyro.h
index c563968e926c..b958c2e9c915 100644
--- a/include/video/kyro.h
+++ b/include/video/kyro.h
@@ -35,9 +35,7 @@ struct kyrofb_info {
 	/* Useful to hold depth here for Linux */
 	u8 PIXDEPTH;
 
-#ifdef CONFIG_MTRR
-	int mtrr_handle;
-#endif
+	int wc_cookie;
 };
 
 extern int kyro_dev_init(void);
-- 
2.4.3

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#1212828 — [tip:x86/mm] drivers/video/fbdev/kyrofb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()

Commit-ID:  9e517ac88b2443bebc0499c0b477b155d63648a7
Gitweb:     http://git.kernel.org/tip/9e517ac88b2443bebc0499c0b477b155d63648a7
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:25 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:44 +0200

drivers/video/fbdev/kyrofb: Use arch_phys_wc_add() and pci_ioremap_wc_bar()

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
   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 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: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tomi 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.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/video/fbdev/kyro/fbdev.c | 33 +++++++++++----------------------
 include/video/kyro.h             |  4 +---
 2 files changed, 12 insertions(+), 25 deletions(-)

diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c
index 65041e1..5bb0153 100644
--- a/drivers/video/fbdev/kyro/fbdev.c
+++ b/drivers/video/fbdev/kyro/fbdev.c
@@ -22,9 +22,6 @@
 #include <linux/pci.h>
 #include <asm/io.h>
 #include <linux/uaccess.h>
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
 
 #include <video/kyro.h>
 
@@ -84,9 +81,7 @@ static device_info_t deviceInfo;
 static char *mode_option = NULL;
 static int nopan = 0;
 static int nowrap = 1;
-#ifdef CONFIG_MTRR
 static int nomtrr = 0;
-#endif
 
 /* PCI driver prototypes */
 static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
@@ -570,10 +565,8 @@ static int __init kyrofb_setup(char *options)
 			nopan = 1;
 		} else if (strcmp(this_opt, "nowrap") == 0) {
 			nowrap = 1;
-#ifdef CONFIG_MTRR
 		} else if (strcmp(this_opt, "nomtrr") == 0) {
 			nomtrr = 1;
-#endif
 		} else {
 			mode_option = this_opt;
 		}
@@ -691,17 +684,16 @@ static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	currentpar->regbase = deviceInfo.pSTGReg =
 		ioremap_nocache(kyro_fix.mmio_start, kyro_fix.mmio_len);
+	if (!currentpar->regbase)
+		goto out_free_fb;
 
-	info->screen_base = ioremap_nocache(kyro_fix.smem_start,
-					    kyro_fix.smem_len);
+	info->screen_base = pci_ioremap_wc_bar(pdev, 0);
+	if (!info->screen_base)
+		goto out_unmap_regs;
 
-#ifdef CONFIG_MTRR
 	if (!nomtrr)
-		currentpar->mtrr_handle =
-			mtrr_add(kyro_fix.smem_start,
-				 kyro_fix.smem_len,
-				 MTRR_TYPE_WRCOMB, 1);
-#endif
+		currentpar->wc_cookie = arch_phys_wc_add(kyro_fix.smem_start,
+							 kyro_fix.smem_len);
 
 	kyro_fix.ypanstep	= nopan ? 0 : 1;
 	kyro_fix.ywrapstep	= nowrap ? 0 : 1;
@@ -745,8 +737,10 @@ static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	return 0;
 
 out_unmap:
-	iounmap(currentpar->regbase);
 	iounmap(info->screen_base);
+out_unmap_regs:
+	iounmap(currentpar->regbase);
+out_free_fb:
 	framebuffer_release(info);
 
 	return -EINVAL;
@@ -770,12 +764,7 @@ static void kyrofb_remove(struct pci_dev *pdev)
 	iounmap(info->screen_base);
 	iounmap(par->regbase);
 
-#ifdef CONFIG_MTRR
-	if (par->mtrr_handle)
-		mtrr_del(par->mtrr_handle,
-			 info->fix.smem_start,
-			 info->fix.smem_len);
-#endif
+	arch_phys_wc_del(par->wc_cookie);
 
 	unregister_framebuffer(info);
 	framebuffer_release(info);
diff --git a/include/video/kyro.h b/include/video/kyro.h
index c563968..b958c2e 100644
--- a/include/video/kyro.h
+++ b/include/video/kyro.h
@@ -35,9 +35,7 @@ struct kyrofb_info {
 	/* Useful to hold depth here for Linux */
 	u8 PIXDEPTH;
 
-#ifdef CONFIG_MTRR
-	int mtrr_handle;
-#endif
+	int wc_cookie;
 };
 
 extern int kyro_dev_init(void);
--
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#1212440 — [PATCH v4 05/11] PCI: Add pci_iomap_wc() variants

From: "Luis R. Rodriguez" <mcgrof@suse.com>

PCI BARs tell us whether prefetching is safe, but they don't say
anything about write combining (WC). WC changes ordering rules and
allows writes to be collapsed, so it's not safe in general to use it on
a prefetchable region.

Add pci_iomap_wc() and pci_iomap_wc_range() so drivers can take advantage
of write combining when they know it's safe.

On architectures that don't fully support WC, e.g., x86 without PAT,
drivers for legacy framebuffers may get some of the benefit by using
arch_phys_wc_add() in addition to pci_iomap_wc().  But arch_phys_wc_add()
is unreliable and should be avoided in general.  On x86, it uses MTRRs,
which are limited in number and size, so the results will vary based on
driver loading order.

The goals of adding pci_iomap_wc() are to:

- Give drivers an architecture-independent way to use WC so they can stop
  using interfaces like mtrr_add() (on x86, pci_iomap_wc() uses
  PAT when available).

- Move toward using _PAGE_CACHE_MODE_UC, not _PAGE_CACHE_MODE_UC_MINUS,
  on x86 on ioremap_nocache() (see de33c442ed2a ("x86 PAT: fix
  performance drop for glx, use UC minus for ioremap(), ioremap_nocache()
  and pci_mmap_page_range()").

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
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: benh@kernel.crashing.org
Cc: bhelgaas@google.com
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: david.vrabel@citrix.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: jbeulich@suse.com
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: konrad.wilk@oracle.com
Cc: linux-arch@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: Mel Gorman <mgorman@suse.de>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: venkatesh.pallipadi@intel.com
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Link: http://lkml.kernel.org/r/1426893517-2511-6-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1435195342-26879-6-git-send-email-mcgrof@do-not-panic.com
[ Move IORESOURCE_IO check up, space out statements for better readability. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 include/asm-generic/pci_iomap.h | 14 +++++++++
 lib/pci_iomap.c                 | 66 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/include/asm-generic/pci_iomap.h b/include/asm-generic/pci_iomap.h
index 7389c87116a0..b1e17fcee2d0 100644
--- a/include/asm-generic/pci_iomap.h
+++ b/include/asm-generic/pci_iomap.h
@@ -15,9 +15,13 @@ struct pci_dev;
 #ifdef CONFIG_PCI
 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
 extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+extern void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long max);
 extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
 				     unsigned long offset,
 				     unsigned long maxlen);
+extern void __iomem *pci_iomap_wc_range(struct pci_dev *dev, int bar,
+					unsigned long offset,
+					unsigned long maxlen);
 /* Create a virtual mapping cookie for a port on a given PCI device.
  * Do not call this directly, it exists to make it easier for architectures
  * to override */
@@ -34,12 +38,22 @@ static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned lon
 	return NULL;
 }
 
+static inline void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long max)
+{
+	return NULL;
+}
 static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
 					    unsigned long offset,
 					    unsigned long maxlen)
 {
 	return NULL;
 }
+static inline void __iomem *pci_iomap_wc_range(struct pci_dev *dev, int bar,
+					       unsigned long offset,
+					       unsigned long maxlen)
+{
+	return NULL;
+}
 #endif
 
 #endif /* __ASM_GENERIC_IO_H */
diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c
index e1930dbab2da..c10fba461454 100644
--- a/lib/pci_iomap.c
+++ b/lib/pci_iomap.c
@@ -49,6 +49,51 @@ void __iomem *pci_iomap_range(struct pci_dev *dev,
 EXPORT_SYMBOL(pci_iomap_range);
 
 /**
+ * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @offset: map memory at the given offset in BAR
+ * @maxlen: max length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way. When possible write combining
+ * is used.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR from offset to the end, pass %0 here.
+ * */
+void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
+				 int bar,
+				 unsigned long offset,
+				 unsigned long maxlen)
+{
+	resource_size_t start = pci_resource_start(dev, bar);
+	resource_size_t len = pci_resource_len(dev, bar);
+	unsigned long flags = pci_resource_flags(dev, bar);
+
+
+	if (flags & IORESOURCE_IO)
+		return NULL;
+
+	if (len <= offset || !start)
+		return NULL;
+
+	len -= offset;
+	start += offset;
+	if (maxlen && len > maxlen)
+		len = maxlen;
+
+	if (flags & IORESOURCE_MEM)
+		return ioremap_wc(start, len);
+
+	/* What? */
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pci_iomap_wc_range);
+
+/**
  * pci_iomap - create a virtual mapping cookie for a PCI BAR
  * @dev: PCI device that owns the BAR
  * @bar: BAR number
@@ -67,4 +112,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 	return pci_iomap_range(dev, bar, 0, maxlen);
 }
 EXPORT_SYMBOL(pci_iomap);
+
+/**
+ * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @maxlen: length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way. When possible write combining
+ * is used.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR without checking for its length first, pass %0 here.
+ * */
+void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+	return pci_iomap_wc_range(dev, bar, 0, maxlen);
+}
+EXPORT_SYMBOL_GPL(pci_iomap_wc);
 #endif /* CONFIG_PCI */
-- 
2.4.3

--
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#1212831 — [tip:x86/mm] PCI: Add pci_iomap_wc() variants

Commit-ID:  1b3d4200c1e00a3fb5e0aea428de5b07079a37e3
Gitweb:     http://git.kernel.org/tip/1b3d4200c1e00a3fb5e0aea428de5b07079a37e3
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:27 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:45 +0200

PCI: Add pci_iomap_wc() variants

PCI BARs tell us whether prefetching is safe, but they don't say
anything about write combining (WC). WC changes ordering rules
and allows writes to be collapsed, so it's not safe in general
to use it on a prefetchable region.

Add pci_iomap_wc() and pci_iomap_wc_range() so drivers can take
advantage of write combining when they know it's safe.

On architectures that don't fully support WC, e.g., x86 without
PAT, drivers for legacy framebuffers may get some of the benefit
by using arch_phys_wc_add() in addition to pci_iomap_wc().  But
arch_phys_wc_add() is unreliable and should be avoided in
general.  On x86, it uses MTRRs, which are limited in number and
size, so the results will vary based on driver loading order.

The goals of adding pci_iomap_wc() are to:

- Give drivers an architecture-independent way to use WC so they can stop
  using interfaces like mtrr_add() (on x86, pci_iomap_wc() uses
  PAT when available).

- Move toward using _PAGE_CACHE_MODE_UC, not _PAGE_CACHE_MODE_UC_MINUS,
  on x86 on ioremap_nocache() (see de33c442ed2a ("x86 PAT: fix
  performance drop for glx, use UC minus for ioremap(), ioremap_nocache()
  and pci_mmap_page_range()").

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
[ Move IORESOURCE_IO check up, space out statements for better readability. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: <roger.pau@citrix.com>
Cc: <syrjala@sci.fi>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roger Pau Monné <roger.pau@citrix.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Stefan Bader <stefan.bader@canonical.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: airlied@linux.ie
Cc: benh@kernel.crashing.org
Cc: dan.j.williams@intel.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-arch@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: venkatesh.pallipadi@intel.com
Cc: vinod.koul@intel.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1440443613-13696-6-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 include/asm-generic/pci_iomap.h | 14 +++++++++
 lib/pci_iomap.c                 | 66 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 80 insertions(+)

diff --git a/include/asm-generic/pci_iomap.h b/include/asm-generic/pci_iomap.h
index 7389c87..b1e17fc 100644
--- a/include/asm-generic/pci_iomap.h
+++ b/include/asm-generic/pci_iomap.h
@@ -15,9 +15,13 @@ struct pci_dev;
 #ifdef CONFIG_PCI
 /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
 extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
+extern void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long max);
 extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
 				     unsigned long offset,
 				     unsigned long maxlen);
+extern void __iomem *pci_iomap_wc_range(struct pci_dev *dev, int bar,
+					unsigned long offset,
+					unsigned long maxlen);
 /* Create a virtual mapping cookie for a port on a given PCI device.
  * Do not call this directly, it exists to make it easier for architectures
  * to override */
@@ -34,12 +38,22 @@ static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned lon
 	return NULL;
 }
 
+static inline void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long max)
+{
+	return NULL;
+}
 static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
 					    unsigned long offset,
 					    unsigned long maxlen)
 {
 	return NULL;
 }
+static inline void __iomem *pci_iomap_wc_range(struct pci_dev *dev, int bar,
+					       unsigned long offset,
+					       unsigned long maxlen)
+{
+	return NULL;
+}
 #endif
 
 #endif /* __ASM_GENERIC_IO_H */
diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c
index bcce5f1..5f5d24d 100644
--- a/lib/pci_iomap.c
+++ b/lib/pci_iomap.c
@@ -52,6 +52,51 @@ void __iomem *pci_iomap_range(struct pci_dev *dev,
 EXPORT_SYMBOL(pci_iomap_range);
 
 /**
+ * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @offset: map memory at the given offset in BAR
+ * @maxlen: max length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way. When possible write combining
+ * is used.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR from offset to the end, pass %0 here.
+ * */
+void __iomem *pci_iomap_wc_range(struct pci_dev *dev,
+				 int bar,
+				 unsigned long offset,
+				 unsigned long maxlen)
+{
+	resource_size_t start = pci_resource_start(dev, bar);
+	resource_size_t len = pci_resource_len(dev, bar);
+	unsigned long flags = pci_resource_flags(dev, bar);
+
+
+	if (flags & IORESOURCE_IO)
+		return NULL;
+
+	if (len <= offset || !start)
+		return NULL;
+
+	len -= offset;
+	start += offset;
+	if (maxlen && len > maxlen)
+		len = maxlen;
+
+	if (flags & IORESOURCE_MEM)
+		return ioremap_wc(start, len);
+
+	/* What? */
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(pci_iomap_wc_range);
+
+/**
  * pci_iomap - create a virtual mapping cookie for a PCI BAR
  * @dev: PCI device that owns the BAR
  * @bar: BAR number
@@ -70,4 +115,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
 	return pci_iomap_range(dev, bar, 0, maxlen);
 }
 EXPORT_SYMBOL(pci_iomap);
+
+/**
+ * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @maxlen: length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way. When possible write combining
+ * is used.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR without checking for its length first, pass %0 here.
+ * */
+void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+	return pci_iomap_wc_range(dev, bar, 0, maxlen);
+}
+EXPORT_SYMBOL_GPL(pci_iomap_wc);
 #endif /* CONFIG_PCI */
--
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#1212441 — [PATCH v4 08/11] drivers/video/fbdev/vt8623fb: Use arch_phys_wc_add() and pci_iomap_wc()

From: "Luis R. Rodriguez" <mcgrof@suse.com>

This driver uses the same area for MTRR as for the ioremap().

Convert the driver from using the x86-specific MTRR code to the
architecture-agnostic arch_phys_wc_add(). It will avoid MTRRs 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
   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 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: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Tomi 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: benh@kernel.crashing.org
Cc: bhelgaas@google.com
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: mst@redhat.com
Cc: Rob Clark <robdclark@gmail.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1435195342-26879-10-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/video/fbdev/vt8623fb.c | 31 ++++++-------------------------
 1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/drivers/video/fbdev/vt8623fb.c b/drivers/video/fbdev/vt8623fb.c
index 8bac309c24b9..dd0f18e42d3e 100644
--- a/drivers/video/fbdev/vt8623fb.c
+++ b/drivers/video/fbdev/vt8623fb.c
@@ -26,13 +26,9 @@
 #include <linux/console.h> /* Why should fb driver call console functions? because console_lock() */
 #include <video/vga.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 struct vt8623fb_info {
 	char __iomem *mmio_base;
-	int mtrr_reg;
+	int wc_cookie;
 	struct vgastate state;
 	struct mutex open_lock;
 	unsigned int ref_count;
@@ -99,10 +95,7 @@ static struct svga_timing_regs vt8623_timing_regs     = {
 /* Module parameters */
 
 static char *mode_option = "640x480-8@60";
-
-#ifdef CONFIG_MTRR
 static int mtrr = 1;
-#endif
 
 MODULE_AUTHOR("(c) 2006 Ondrej Zajicek <santiago@crfreenet.org>");
 MODULE_LICENSE("GPL");
@@ -112,11 +105,8 @@ module_param(mode_option, charp, 0644);
 MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
 module_param_named(mode, mode_option, charp, 0);
 MODULE_PARM_DESC(mode, "Default video mode e.g. '648x480-8@60' (deprecated)");
-
-#ifdef CONFIG_MTRR
 module_param(mtrr, int, 0444);
 MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
-#endif
 
 
 /* ------------------------------------------------------------------------- */
@@ -710,7 +700,7 @@ static int vt8623_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	info->fix.mmio_len = pci_resource_len(dev, 1);
 
 	/* Map physical IO memory address into kernel space */
-	info->screen_base = pci_iomap(dev, 0, 0);
+	info->screen_base = pci_iomap_wc(dev, 0, 0);
 	if (! info->screen_base) {
 		rc = -ENOMEM;
 		dev_err(info->device, "iomap for framebuffer failed\n");
@@ -781,12 +771,9 @@ static int vt8623_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	/* Record a reference to the driver data */
 	pci_set_drvdata(dev, info);
 
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		par->mtrr_reg = -1;
-		par->mtrr_reg = mtrr_add(info->fix.smem_start, info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
-	}
-#endif
+	if (mtrr)
+		par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+						  info->fix.smem_len);
 
 	return 0;
 
@@ -816,13 +803,7 @@ static void vt8623_pci_remove(struct pci_dev *dev)
 	if (info) {
 		struct vt8623fb_info *par = info->par;
 
-#ifdef CONFIG_MTRR
-		if (par->mtrr_reg >= 0) {
-			mtrr_del(par->mtrr_reg, 0, 0);
-			par->mtrr_reg = -1;
-		}
-#endif
-
+		arch_phys_wc_del(par->wc_cookie);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);
 
-- 
2.4.3

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#1212815 — [tip:x86/mm] drivers/video/fbdev/vt8623fb: Use arch_phys_wc_add() and pci_iomap_wc()

Commit-ID:  81bdef04d3bc76fc516ca613fa96061ff27bced9
Gitweb:     http://git.kernel.org/tip/81bdef04d3bc76fc516ca613fa96061ff27bced9
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:30 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:45 +0200

drivers/video/fbdev/vt8623fb: Use arch_phys_wc_add() and pci_iomap_wc()

This driver uses the same area for MTRR as for the ioremap().

Convert the driver from using the x86-specific MTRR code to the
architecture-agnostic arch_phys_wc_add(). It will avoid MTRRs 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
   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 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: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tomi 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: 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: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Clark <robdclark@gmail.com>
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/1440443613-13696-9-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/video/fbdev/vt8623fb.c | 31 ++++++-------------------------
 1 file changed, 6 insertions(+), 25 deletions(-)

diff --git a/drivers/video/fbdev/vt8623fb.c b/drivers/video/fbdev/vt8623fb.c
index 8bac309..dd0f18e 100644
--- a/drivers/video/fbdev/vt8623fb.c
+++ b/drivers/video/fbdev/vt8623fb.c
@@ -26,13 +26,9 @@
 #include <linux/console.h> /* Why should fb driver call console functions? because console_lock() */
 #include <video/vga.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 struct vt8623fb_info {
 	char __iomem *mmio_base;
-	int mtrr_reg;
+	int wc_cookie;
 	struct vgastate state;
 	struct mutex open_lock;
 	unsigned int ref_count;
@@ -99,10 +95,7 @@ static struct svga_timing_regs vt8623_timing_regs     = {
 /* Module parameters */
 
 static char *mode_option = "640x480-8@60";
-
-#ifdef CONFIG_MTRR
 static int mtrr = 1;
-#endif
 
 MODULE_AUTHOR("(c) 2006 Ondrej Zajicek <santiago@crfreenet.org>");
 MODULE_LICENSE("GPL");
@@ -112,11 +105,8 @@ module_param(mode_option, charp, 0644);
 MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
 module_param_named(mode, mode_option, charp, 0);
 MODULE_PARM_DESC(mode, "Default video mode e.g. '648x480-8@60' (deprecated)");
-
-#ifdef CONFIG_MTRR
 module_param(mtrr, int, 0444);
 MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
-#endif
 
 
 /* ------------------------------------------------------------------------- */
@@ -710,7 +700,7 @@ static int vt8623_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	info->fix.mmio_len = pci_resource_len(dev, 1);
 
 	/* Map physical IO memory address into kernel space */
-	info->screen_base = pci_iomap(dev, 0, 0);
+	info->screen_base = pci_iomap_wc(dev, 0, 0);
 	if (! info->screen_base) {
 		rc = -ENOMEM;
 		dev_err(info->device, "iomap for framebuffer failed\n");
@@ -781,12 +771,9 @@ static int vt8623_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	/* Record a reference to the driver data */
 	pci_set_drvdata(dev, info);
 
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		par->mtrr_reg = -1;
-		par->mtrr_reg = mtrr_add(info->fix.smem_start, info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
-	}
-#endif
+	if (mtrr)
+		par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+						  info->fix.smem_len);
 
 	return 0;
 
@@ -816,13 +803,7 @@ static void vt8623_pci_remove(struct pci_dev *dev)
 	if (info) {
 		struct vt8623fb_info *par = info->par;
 
-#ifdef CONFIG_MTRR
-		if (par->mtrr_reg >= 0) {
-			mtrr_del(par->mtrr_reg, 0, 0);
-			par->mtrr_reg = -1;
-		}
-#endif
-
+		arch_phys_wc_del(par->wc_cookie);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);
 
--
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#1212442 — [PATCH v4 11/11] mtrr: bury MTRR - unexport mtrr_add() and mtrr_del()

From: "Luis R. Rodriguez" <mcgrof@suse.com>

The crusade to replace mtrr_add() with architecture agnostic
arch_phys_wc_add() is complete, this will ensure write-combining
implementations (PAT on x86) is taken advantage instead of using
MTRR. With the crusade done now, hide direct MTRR access for
drivers.

Update x86 documentation on MTRR to reflect the completion of the
phasing out of direct access to MTRR, also add a note on platform
firmware code use of MTRRs based on the obituary discussion of
MTRRs on Linux [0].

[0] http://lkml.kernel.org/r/1438991330.3109.196.camel@hp.com

Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Juergen Gross <jgross@suse.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: x86@kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
---
 Documentation/x86/mtrr.txt      | 20 ++++++++++++++++----
 arch/x86/kernel/cpu/mtrr/main.c |  2 --
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/Documentation/x86/mtrr.txt b/Documentation/x86/mtrr.txt
index 860bc3adc223..8a0bdb6e7370 100644
--- a/Documentation/x86/mtrr.txt
+++ b/Documentation/x86/mtrr.txt
@@ -6,10 +6,22 @@ Luis R. Rodriguez <mcgrof@do-not-panic.com> - April 9, 2015
 ===============================================================================
 Phasing out MTRR use
 
-MTRR use is replaced on modern x86 hardware with PAT. Over time the only type
-of effective MTRR that is expected to be supported will be for write-combining.
-As MTRR use is phased out device drivers should use arch_phys_wc_add() to make
-MTRR effective on non-PAT systems while a no-op on PAT enabled systems.
+MTRR use is replaced on modern x86 hardware with PAT. Direct MTRR use by
+drivers on Linux is now completely phased out, device drivers should use
+arch_phys_wc_add() in combination with ioremap_wc() to make MTRR effective on
+non-PAT systems while a no-op but equally effective on PAT enabled systems.
+
+Even if Linux does not use MTRR directly some x86 platform firmware may still
+set up MTRRs early before booting the OS, they do this as some platform
+firmware may still have implemented access to MTRRs which would be controlled
+and handled by the platform firmware directly. An example of platform use of
+MTRR is through the use of SMI handlers, one case could be for fan control,
+the platform code would need uncachable access to some of its fan control
+registers. Such platform access does not need any Operating System MTRR code in
+place other than mtrr_type_lookup() to ensure any OS specific mapping requests
+are aligned with platform MTRR setup. If MTRRs are only set up by the platform
+firmware code though and the OS does not make any specific MTRR mapping
+requests mtrr_type_lookup() should always return MTRR_TYPE_INVALID.
 
 For details refer to Documentation/x86/pat.txt.
 
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index e7ed0d8ebacb..f891b4750f04 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -448,7 +448,6 @@ int mtrr_add(unsigned long base, unsigned long size, unsigned int type,
 	return mtrr_add_page(base >> PAGE_SHIFT, size >> PAGE_SHIFT, type,
 			     increment);
 }
-EXPORT_SYMBOL(mtrr_add);
 
 /**
  * mtrr_del_page - delete a memory type region
@@ -537,7 +536,6 @@ int mtrr_del(int reg, unsigned long base, unsigned long size)
 		return -EINVAL;
 	return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT);
 }
-EXPORT_SYMBOL(mtrr_del);
 
 /**
  * arch_phys_wc_add - add a WC MTRR and handle errors if PAT is unavailable
-- 
2.4.3

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#1215213 — [tip:x86/mm] x86/mm/mtrr: Remove kernel internal MTRR interfaces: unexport mtrr_add() and mtrr_del()

Commit-ID:  2baa891e42d84159b693eadd44f6fe1486285bdc
Gitweb:     http://git.kernel.org/tip/2baa891e42d84159b693eadd44f6fe1486285bdc
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:33 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Fri, 28 Aug 2015 10:09:28 +0200

x86/mm/mtrr: Remove kernel internal MTRR interfaces: unexport mtrr_add() and mtrr_del()

The effort to replace mtrr_add() with architecture agnostic
arch_phys_wc_add() is complete, this will ensure write-combining
implementations (PAT on x86) is taken advantage instead of using
MTRR. With the effort done now, hide direct MTRR access for
drivers.

The legacy user-space /proc/mtrr ABI is not affected.

Update x86 documentation on MTRR to reflect the completion of
the phasing out of direct access to MTRR, also add a note on
platform firmware code use of MTRRs based on the obituary
discussion of MTRRs on Linux [0].

  [0] http://lkml.kernel.org/r/1438991330.3109.196.camel@hp.com

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Cc: <syrjala@sci.fi>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Walls <awalls@md.metrocast.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Doug Ledford <dledford@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Ville Syrjälä <syrjala@sci.fi>
Cc: Vlastimil Babka <vbabka@suse.cz>
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-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: mst@redhat.com
Cc: netdev@vger.kernel.org
Cc: vinod.koul@intel.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1440443613-13696-12-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 Documentation/x86/mtrr.txt      | 20 ++++++++++++++++----
 arch/x86/kernel/cpu/mtrr/main.c |  2 --
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/Documentation/x86/mtrr.txt b/Documentation/x86/mtrr.txt
index 860bc3a..dc3e703 100644
--- a/Documentation/x86/mtrr.txt
+++ b/Documentation/x86/mtrr.txt
@@ -6,10 +6,22 @@ Luis R. Rodriguez <mcgrof@do-not-panic.com> - April 9, 2015
 ===============================================================================
 Phasing out MTRR use
 
-MTRR use is replaced on modern x86 hardware with PAT. Over time the only type
-of effective MTRR that is expected to be supported will be for write-combining.
-As MTRR use is phased out device drivers should use arch_phys_wc_add() to make
-MTRR effective on non-PAT systems while a no-op on PAT enabled systems.
+MTRR use is replaced on modern x86 hardware with PAT. Direct MTRR use by
+drivers on Linux is now completely phased out, device drivers should use
+arch_phys_wc_add() in combination with ioremap_wc() to make MTRR effective on
+non-PAT systems while a no-op but equally effective on PAT enabled systems.
+
+Even if Linux does not use MTRRs directly, some x86 platform firmware may still
+set up MTRRs early before booting the OS. They do this as some platform
+firmware may still have implemented access to MTRRs which would be controlled
+and handled by the platform firmware directly. An example of platform use of
+MTRRs is through the use of SMI handlers, one case could be for fan control,
+the platform code would need uncachable access to some of its fan control
+registers. Such platform access does not need any Operating System MTRR code in
+place other than mtrr_type_lookup() to ensure any OS specific mapping requests
+are aligned with platform MTRR setup. If MTRRs are only set up by the platform
+firmware code though and the OS does not make any specific MTRR mapping
+requests mtrr_type_lookup() should always return MTRR_TYPE_INVALID.
 
 For details refer to Documentation/x86/pat.txt.
 
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index e7ed0d8..f891b47 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -448,7 +448,6 @@ int mtrr_add(unsigned long base, unsigned long size, unsigned int type,
 	return mtrr_add_page(base >> PAGE_SHIFT, size >> PAGE_SHIFT, type,
 			     increment);
 }
-EXPORT_SYMBOL(mtrr_add);
 
 /**
  * mtrr_del_page - delete a memory type region
@@ -537,7 +536,6 @@ int mtrr_del(int reg, unsigned long base, unsigned long size)
 		return -EINVAL;
 	return mtrr_del_page(reg, base >> PAGE_SHIFT, size >> PAGE_SHIFT);
 }
-EXPORT_SYMBOL(mtrr_del);
 
 /**
  * arch_phys_wc_add - add a WC MTRR and handle errors if PAT is unavailable
--
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#1212443 — [PATCH v4 09/11] drivers/dma/iop-adma: Use dma_alloc_writecombine() kernel-style

From: "Luis R. Rodriguez" <mcgrof@suse.com>

dma_alloc_writecombine()'s call and return value check is tangled in all
in one call. Untangle both calls according to kernel coding style.

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: dmaengine@vger.kernel.org
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/1435258191-543-2-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/dma/iop-adma.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c
index 998826854fdd..e4f43125e0fb 100644
--- a/drivers/dma/iop-adma.c
+++ b/drivers/dma/iop-adma.c
@@ -1300,10 +1300,11 @@ static int iop_adma_probe(struct platform_device *pdev)
 	 * note: writecombine gives slightly better performance, but
 	 * requires that we explicitly flush the writes
 	 */
-	if ((adev->dma_desc_pool_virt = dma_alloc_writecombine(&pdev->dev,
-					plat_data->pool_size,
-					&adev->dma_desc_pool,
-					GFP_KERNEL)) == NULL) {
+	adev->dma_desc_pool_virt = dma_alloc_writecombine(&pdev->dev,
+							  plat_data->pool_size,
+							  &adev->dma_desc_pool,
+							  GFP_KERNEL);
+	if (!adev->dma_desc_pool_virt) {
 		ret = -ENOMEM;
 		goto err_free_adev;
 	}
-- 
2.4.3

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#1212824 — [tip:x86/mm] drivers/dma/iop-adma: Use dma_alloc_writecombine() kernel-style

Commit-ID:  39c33704420b147fb7e193a9f406cc8420a1d610
Gitweb:     http://git.kernel.org/tip/39c33704420b147fb7e193a9f406cc8420a1d610
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:31 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:46 +0200

drivers/dma/iop-adma: Use dma_alloc_writecombine() kernel-style

dma_alloc_writecombine()'s call and return value check is
tangled in all in one call. Untangle both calls according to
kernel coding style.

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: benh@kernel.crashing.org
Cc: bhelgaas@google.com
Cc: daniel.vetter@ffwll.ch
Cc: dmaengine@vger.kernel.org
Cc: konrad.wilk@oracle.com
Cc: luto@amacapital.net
Cc: mst@redhat.com
Cc: tomi.valkeinen@ti.com
Cc: toshi.kani@hp.com
Cc: xen-devel@lists.xensource.com
Link: http://lkml.kernel.org/r/1440443613-13696-10-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/dma/iop-adma.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c
index 9988268..e4f4312 100644
--- a/drivers/dma/iop-adma.c
+++ b/drivers/dma/iop-adma.c
@@ -1300,10 +1300,11 @@ static int iop_adma_probe(struct platform_device *pdev)
 	 * note: writecombine gives slightly better performance, but
 	 * requires that we explicitly flush the writes
 	 */
-	if ((adev->dma_desc_pool_virt = dma_alloc_writecombine(&pdev->dev,
-					plat_data->pool_size,
-					&adev->dma_desc_pool,
-					GFP_KERNEL)) == NULL) {
+	adev->dma_desc_pool_virt = dma_alloc_writecombine(&pdev->dev,
+							  plat_data->pool_size,
+							  &adev->dma_desc_pool,
+							  GFP_KERNEL);
+	if (!adev->dma_desc_pool_virt) {
 		ret = -ENOMEM;
 		goto err_free_adev;
 	}
--
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#1212444 — [PATCH v4 04/11] drivers/video/fbdev/gxt4500: Use pci_ioremap_wc_bar() to map framebuffer

From: "Luis R. Rodriguez" <mcgrof@suse.com>

The driver doesn't use mtrr_add() or arch_phys_wc_add() but since we
know the framebuffer is isolated already on an ioremap() we can take
advantage of write combining for performance where possible.

In this case there are a few motivations for this:

a) Take advantage of PAT when available.

b) 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()").

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Tomi 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: benh@kernel.crashing.org
Cc: bhelgaas@google.com
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: Ingo Molnar <mingo@kernel.org>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: mst@redhat.com
Cc: Rob Clark <robdclark@gmail.com>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1435195342-26879-5-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/video/fbdev/gxt4500.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/gxt4500.c b/drivers/video/fbdev/gxt4500.c
index 135d78a02588..f19133a80e8c 100644
--- a/drivers/video/fbdev/gxt4500.c
+++ b/drivers/video/fbdev/gxt4500.c
@@ -662,7 +662,7 @@ static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	info->fix.smem_start = fb_phys;
 	info->fix.smem_len = pci_resource_len(pdev, 1);
-	info->screen_base = pci_ioremap_bar(pdev, 1);
+	info->screen_base = pci_ioremap_wc_bar(pdev, 1);
 	if (!info->screen_base) {
 		dev_err(&pdev->dev, "gxt4500: cannot map framebuffer\n");
 		goto err_unmap_regs;
-- 
2.4.3

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#1212823 — [tip:x86/mm] drivers/video/fbdev/gxt4500: Use pci_ioremap_wc_bar( ) to map framebuffer

Commit-ID:  f3adccbd75831f3651ca6e2cbb83f27cd68a27c9
Gitweb:     http://git.kernel.org/tip/f3adccbd75831f3651ca6e2cbb83f27cd68a27c9
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:26 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:44 +0200

drivers/video/fbdev/gxt4500: Use pci_ioremap_wc_bar() to map framebuffer

The driver doesn't use mtrr_add() or arch_phys_wc_add() but
since we know the framebuffer is isolated already on an
ioremap() we can take advantage of write combining for
performance where possible.

In this case there are a few motivations for this:

a) Take advantage of PAT when available.

b) 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()").

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tomi 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: 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: Rob Clark <robdclark@gmail.com>
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/1440443613-13696-5-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/video/fbdev/gxt4500.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/gxt4500.c b/drivers/video/fbdev/gxt4500.c
index 135d78a..f19133a 100644
--- a/drivers/video/fbdev/gxt4500.c
+++ b/drivers/video/fbdev/gxt4500.c
@@ -662,7 +662,7 @@ static int gxt4500_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	info->fix.smem_start = fb_phys;
 	info->fix.smem_len = pci_resource_len(pdev, 1);
-	info->screen_base = pci_ioremap_bar(pdev, 1);
+	info->screen_base = pci_ioremap_wc_bar(pdev, 1);
 	if (!info->screen_base) {
 		dev_err(&pdev->dev, "gxt4500: cannot map framebuffer\n");
 		goto err_unmap_regs;
--
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#1212445 — [PATCH v4 07/11] drivers/video/fbdev/s3fb: Use arch_phys_wc_add() and pci_iomap_wc()

From: "Luis R. Rodriguez" <mcgrof@suse.com>

This driver uses the same area for MTRR as for the ioremap().

Convert the driver from using the x86-specific MTRR code to the
architecture-agnostic arch_phys_wc_add(). It will avoid MTRRs 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
   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 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: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Tomi 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: benh@kernel.crashing.org
Cc: bhelgaas@google.com
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: Ingo Molnar <mingo@kernel.org>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: mst@redhat.com
Cc: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1435195342-26879-9-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/video/fbdev/s3fb.c | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/drivers/video/fbdev/s3fb.c b/drivers/video/fbdev/s3fb.c
index f0ae61a37f04..13b109073c63 100644
--- a/drivers/video/fbdev/s3fb.c
+++ b/drivers/video/fbdev/s3fb.c
@@ -28,13 +28,9 @@
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 struct s3fb_info {
 	int chip, rev, mclk_freq;
-	int mtrr_reg;
+	int wc_cookie;
 	struct vgastate state;
 	struct mutex open_lock;
 	unsigned int ref_count;
@@ -154,11 +150,7 @@ static const struct svga_timing_regs s3_timing_regs     = {
 
 
 static char *mode_option;
-
-#ifdef CONFIG_MTRR
 static int mtrr = 1;
-#endif
-
 static int fasttext = 1;
 
 
@@ -170,11 +162,8 @@ module_param(mode_option, charp, 0444);
 MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
 module_param_named(mode, mode_option, charp, 0444);
 MODULE_PARM_DESC(mode, "Default video mode ('640x480-8@60', etc) (deprecated)");
-
-#ifdef CONFIG_MTRR
 module_param(mtrr, int, 0444);
 MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
-#endif
 
 module_param(fasttext, int, 0644);
 MODULE_PARM_DESC(fasttext, "Enable S3 fast text mode (1=enable, 0=disable, default=1)");
@@ -1168,7 +1157,7 @@ static int s3_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	info->fix.smem_len = pci_resource_len(dev, 0);
 
 	/* Map physical IO memory address into kernel space */
-	info->screen_base = pci_iomap(dev, 0, 0);
+	info->screen_base = pci_iomap_wc(dev, 0, 0);
 	if (! info->screen_base) {
 		rc = -ENOMEM;
 		dev_err(info->device, "iomap for framebuffer failed\n");
@@ -1365,12 +1354,9 @@ static int s3_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	/* Record a reference to the driver data */
 	pci_set_drvdata(dev, info);
 
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		par->mtrr_reg = -1;
-		par->mtrr_reg = mtrr_add(info->fix.smem_start, info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
-	}
-#endif
+	if (mtrr)
+		par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+						  info->fix.smem_len);
 
 	return 0;
 
@@ -1405,14 +1391,7 @@ static void s3_pci_remove(struct pci_dev *dev)
 
 	if (info) {
 		par = info->par;
-
-#ifdef CONFIG_MTRR
-		if (par->mtrr_reg >= 0) {
-			mtrr_del(par->mtrr_reg, 0, 0);
-			par->mtrr_reg = -1;
-		}
-#endif
-
+		arch_phys_wc_del(par->wc_cookie);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);
 
@@ -1551,10 +1530,8 @@ static int  __init s3fb_setup(char *options)
 
 		if (!*opt)
 			continue;
-#ifdef CONFIG_MTRR
 		else if (!strncmp(opt, "mtrr:", 5))
 			mtrr = simple_strtoul(opt + 5, NULL, 0);
-#endif
 		else if (!strncmp(opt, "fasttext:", 9))
 			fasttext = simple_strtoul(opt + 9, NULL, 0);
 		else
-- 
2.4.3

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#1212821 — [tip:x86/mm] drivers/video/fbdev/s3fb: Use arch_phys_wc_add() and pci_iomap_wc()

Commit-ID:  4edcd2ab125506516c7de038f6e0a6d19dcc411d
Gitweb:     http://git.kernel.org/tip/4edcd2ab125506516c7de038f6e0a6d19dcc411d
Author:     Luis R. Rodriguez <mcgrof@suse.com>
AuthorDate: Mon, 24 Aug 2015 12:13:29 -0700
Committer:  Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 25 Aug 2015 09:59:45 +0200

drivers/video/fbdev/s3fb: Use arch_phys_wc_add() and pci_iomap_wc()

This driver uses the same area for MTRR as for the ioremap().

Convert the driver from using the x86-specific MTRR code to the
architecture-agnostic arch_phys_wc_add(). It will avoid MTRRs 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
   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 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: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tomi 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: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rickard Strandqvist <rickard_strandqvist@spectrumdigital.se>
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/1440443613-13696-8-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 drivers/video/fbdev/s3fb.c | 35 ++++++-----------------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/drivers/video/fbdev/s3fb.c b/drivers/video/fbdev/s3fb.c
index f0ae61a..13b1090 100644
--- a/drivers/video/fbdev/s3fb.c
+++ b/drivers/video/fbdev/s3fb.c
@@ -28,13 +28,9 @@
 #include <linux/i2c.h>
 #include <linux/i2c-algo-bit.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 struct s3fb_info {
 	int chip, rev, mclk_freq;
-	int mtrr_reg;
+	int wc_cookie;
 	struct vgastate state;
 	struct mutex open_lock;
 	unsigned int ref_count;
@@ -154,11 +150,7 @@ static const struct svga_timing_regs s3_timing_regs     = {
 
 
 static char *mode_option;
-
-#ifdef CONFIG_MTRR
 static int mtrr = 1;
-#endif
-
 static int fasttext = 1;
 
 
@@ -170,11 +162,8 @@ module_param(mode_option, charp, 0444);
 MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
 module_param_named(mode, mode_option, charp, 0444);
 MODULE_PARM_DESC(mode, "Default video mode ('640x480-8@60', etc) (deprecated)");
-
-#ifdef CONFIG_MTRR
 module_param(mtrr, int, 0444);
 MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
-#endif
 
 module_param(fasttext, int, 0644);
 MODULE_PARM_DESC(fasttext, "Enable S3 fast text mode (1=enable, 0=disable, default=1)");
@@ -1168,7 +1157,7 @@ static int s3_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	info->fix.smem_len = pci_resource_len(dev, 0);
 
 	/* Map physical IO memory address into kernel space */
-	info->screen_base = pci_iomap(dev, 0, 0);
+	info->screen_base = pci_iomap_wc(dev, 0, 0);
 	if (! info->screen_base) {
 		rc = -ENOMEM;
 		dev_err(info->device, "iomap for framebuffer failed\n");
@@ -1365,12 +1354,9 @@ static int s3_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	/* Record a reference to the driver data */
 	pci_set_drvdata(dev, info);
 
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		par->mtrr_reg = -1;
-		par->mtrr_reg = mtrr_add(info->fix.smem_start, info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
-	}
-#endif
+	if (mtrr)
+		par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+						  info->fix.smem_len);
 
 	return 0;
 
@@ -1405,14 +1391,7 @@ static void s3_pci_remove(struct pci_dev *dev)
 
 	if (info) {
 		par = info->par;
-
-#ifdef CONFIG_MTRR
-		if (par->mtrr_reg >= 0) {
-			mtrr_del(par->mtrr_reg, 0, 0);
-			par->mtrr_reg = -1;
-		}
-#endif
-
+		arch_phys_wc_del(par->wc_cookie);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);
 
@@ -1551,10 +1530,8 @@ static int  __init s3fb_setup(char *options)
 
 		if (!*opt)
 			continue;
-#ifdef CONFIG_MTRR
 		else if (!strncmp(opt, "mtrr:", 5))
 			mtrr = simple_strtoul(opt + 5, NULL, 0);
-#endif
 		else if (!strncmp(opt, "fasttext:", 9))
 			fasttext = simple_strtoul(opt + 9, NULL, 0);
 		else
--
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#1212447 — [PATCH v4 06/11] drivers/video/fbdev/arkfb.c: Use arch_phys_wc_add() and pci_iomap_wc()

From: "Luis R. Rodriguez" <mcgrof@suse.com>

Convert the driver from using the x86-specific MTRR code to the
architecture-agnostic arch_phys_wc_add(). It will avoid MTRRs 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
   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 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: Luis R. Rodriguez <mcgrof@suse.com>
Acked-by: Tomi 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: benh@kernel.crashing.org
Cc: bhelgaas@google.com
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: Ingo Molnar <mingo@kernel.org>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: linux-fbdev@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: mst@redhat.com
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1435195342-26879-8-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/video/fbdev/arkfb.c | 36 +++++-------------------------------
 1 file changed, 5 insertions(+), 31 deletions(-)

diff --git a/drivers/video/fbdev/arkfb.c b/drivers/video/fbdev/arkfb.c
index b305a1e7cc76..6a317de7082c 100644
--- a/drivers/video/fbdev/arkfb.c
+++ b/drivers/video/fbdev/arkfb.c
@@ -26,13 +26,9 @@
 #include <linux/console.h> /* Why should fb driver call console functions? because console_lock() */
 #include <video/vga.h>
 
-#ifdef CONFIG_MTRR
-#include <asm/mtrr.h>
-#endif
-
 struct arkfb_info {
 	int mclk_freq;
-	int mtrr_reg;
+	int wc_cookie;
 
 	struct dac_info *dac;
 	struct vgastate state;
@@ -102,10 +98,6 @@ static const struct svga_timing_regs ark_timing_regs     = {
 
 static char *mode_option = "640x480-8@60";
 
-#ifdef CONFIG_MTRR
-static int mtrr = 1;
-#endif
-
 MODULE_AUTHOR("(c) 2007 Ondrej Zajicek <santiago@crfreenet.org>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("fbdev driver for ARK 2000PV");
@@ -115,11 +107,6 @@ MODULE_PARM_DESC(mode_option, "Default video mode ('640x480-8@60', etc)");
 module_param_named(mode, mode_option, charp, 0444);
 MODULE_PARM_DESC(mode, "Default video mode ('640x480-8@60', etc) (deprecated)");
 
-#ifdef CONFIG_MTRR
-module_param(mtrr, int, 0444);
-MODULE_PARM_DESC(mtrr, "Enable write-combining with MTRR (1=enable, 0=disable, default=1)");
-#endif
-
 static int threshold = 4;
 
 module_param(threshold, int, 0644);
@@ -1002,7 +989,7 @@ static int ark_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	info->fix.smem_len = pci_resource_len(dev, 0);
 
 	/* Map physical IO memory address into kernel space */
-	info->screen_base = pci_iomap(dev, 0, 0);
+	info->screen_base = pci_iomap_wc(dev, 0, 0);
 	if (! info->screen_base) {
 		rc = -ENOMEM;
 		dev_err(info->device, "iomap for framebuffer failed\n");
@@ -1057,14 +1044,8 @@ static int ark_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 
 	/* Record a reference to the driver data */
 	pci_set_drvdata(dev, info);
-
-#ifdef CONFIG_MTRR
-	if (mtrr) {
-		par->mtrr_reg = -1;
-		par->mtrr_reg = mtrr_add(info->fix.smem_start, info->fix.smem_len, MTRR_TYPE_WRCOMB, 1);
-	}
-#endif
-
+	par->wc_cookie = arch_phys_wc_add(info->fix.smem_start,
+					  info->fix.smem_len);
 	return 0;
 
 	/* Error handling */
@@ -1092,14 +1073,7 @@ static void ark_pci_remove(struct pci_dev *dev)
 
 	if (info) {
 		struct arkfb_info *par = info->par;
-
-#ifdef CONFIG_MTRR
-		if (par->mtrr_reg >= 0) {
-			mtrr_del(par->mtrr_reg, 0, 0);
-			par->mtrr_reg = -1;
-		}
-#endif
-
+		arch_phys_wc_del(par->wc_cookie);
 		dac_release(par->dac);
 		unregister_framebuffer(info);
 		fb_dealloc_cmap(&info->cmap);
-- 
2.4.3

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