A recent change to the mm code in:
87744ab3 mm: fix cache mode tracking in vm_insert_mixed()

started enforcing checking the memory type against the registered list for
amixed pfn insertion mappings. It happens that the drm drivers for a number
of gpus relied on this being broken. Currently the driver only inserted
VRAM mappings into the tracking table when they came from the kernel,
and userspace mappings never landed in the table. This led to a regression
where all the mapping end up as UC instead of WC now.

I've considered a number of solutions but since this needs to be fixed
in fixes and not next, and some of the solutions were going to introduce
overhead that hadn't been there before I didn't consider them viable at
this stage. These mainly concerned hooking into the TTM io reserve APIs,
but these API have a bunch of fast paths I didn't want to unwind to add
this to.

The solution I've decided on is to add a new API like the arch_phys_wc
APIs (these would have worked but wc_del didn't take a range), and
use them from the drivers to add a WC compatible mapping to the table
for all VRAM on those GPUs. This means we can then create userspace
mapping that won't get degraded to UC.

v1.1: use CONFIG_X86_PAT + add some comments in io.h

Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: x86@kernel.org
Cc: mcgrof@suse.com
Cc: Dan Williams <dan.j.williams@intel.com>
Acked-by: NIngo Molnar <mingo@kernel.org>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Add a flag to memremap() for writecombine mappings.  Mappings satisfied
by this flag will not be cached, however writes may be delayed or
combined into more efficient bursts.  This is most suitable for buffers
written sequentially by the CPU for use by other DMA devices.
Signed-off-by: NBrian Starkey <brian.starkey@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some drivers need to read data out of iomem areas 32-bits at a time.
Add an API to do this.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Cc: <zajec5@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are several scenarios where we need to retrieve and update
metadata associated with a given devm_memremap_pages() mapping, and the
only lookup key available is a pfn in the range:

1/ We want to augment vmemmap_populate() (called via arch_add_memory())
   to allocate memmap storage from pre-allocated pages reserved by the
   device driver.  At vmemmap_alloc_block_buf() time it grabs device pages
   rather than page allocator pages.  This is in support of
   devm_memremap_pages() mappings where the memmap is too large to fit in
   main memory (i.e. large persistent memory devices).

2/ Taking a reference against the mapping when inserting device pages
   into the address_space radix of a given inode.  This facilitates
   unmap_mapping_range() and truncate_inode_pages() operations when the
   driver is tearing down the mapping.

3/ get_user_pages() operations on ZONE_DEVICE memory require taking a
   reference against the mapping so that the driver teardown path can
   revoke and drain usage of device pages.
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Tested-by: NLogan Gunthorpe <logang@deltatee.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This behaves like devm_memremap except that it ensures we have page
structures available that can back the region.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
[djbw: catch attempts to remap RAM, drop flags]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Existing users of ioremap_cache() are mapping memory that is known in
advance to not have i/o side effects.  These users are forced to cast
away the __iomem annotation, or otherwise neglect to fix the sparse
errors thrown when dereferencing pointers to this memory.  Provide
memremap() as a non __iomem annotated ioremap_*() in the case when
ioremap is otherwise a pointer to cacheable memory. Empirically,
ioremap_<cacheable-type>() call sites are seeking memory-like semantics
(e.g.  speculative reads, and prefetching permitted).

memremap() is a break from the ioremap implementation pattern of adding
a new memremap_<type>() for each mapping type and having silent
compatibility fall backs.  Instead, the implementation defines flags
that are passed to the central memremap() and if a mapping type is not
supported by an arch memremap returns NULL.

We introduce a memremap prototype as a trivial wrapper of
ioremap_cache() and ioremap_wt().  Later, once all ioremap_cache() and
ioremap_wt() usage has been removed from drivers we teach archs to
implement arch_memremap() with the ability to strictly enforce the
mapping type.

Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Nothing in <asm/io.h> uses anything from <linux/vmalloc.h>, so
remove it from there and fix up the resulting build problems
triggered on x86 {64|32}-bit {def|allmod|allno}configs.

The breakages were triggering in places where x86 builds relied
on vmalloc() facilities but did not include <linux/vmalloc.h>
explicitly and relied on the implicit inclusion via <asm/io.h>.

Also add:

  - <linux/init.h> to <linux/io.h>
  - <asm/pgtable_types> to <asm/io.h>

... which were two other implicit header file dependencies.
Suggested-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
[ Tidied up the changelog. ]
Acked-by: NDavid Miller <davem@davemloft.net>
Acked-by: NTakashi Iwai <tiwai@suse.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NVinod Koul <vinod.koul@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Colin Cross <ccross@android.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Suma Ramars <sramars@cisco.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

There is only one user but since we're going to bury MTRR next
out of access to drivers, expose this last piece of API to
drivers in a general fashion only needing io.h for access to
helpers.
Signed-off-by: NLuis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Abhilash Kesavan <a.kesavan@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Cristian Stoica <cristian.stoica@freescale.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: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Siddha <sbsiddha@gmail.com>
Cc: Thierry Reding <treding@nvidia.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: Will Deacon <will.deacon@arm.com>
Cc: dri-devel@lists.freedesktop.org
Link: http://lkml.kernel.org/r/1429722736-4473-1-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1432628901-18044-11-git-send-email-bp@alien8.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when
I/O mappings with pud/pmd are enabled on the kernel.

ioremap_huge_init() calls arch_ioremap_pud_supported() and
arch_ioremap_pmd_supported() to initialize the capabilities at boot-time.

A new kernel option "nohugeiomap" is also added, so that user can disable
the huge I/O map capabilities when necessary.
Signed-off-by: NToshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Implement a resource managed writecombine ioremap function.
Signed-off-by: NAbhilash Kesavan <a.kesavan@samsung.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As in 4f452e8a, use resource_size_t
to accomodate sizes greater than the size of an unsigned long int on
platforms that have more than 32 bit physical addresses.
Signed-off-by: NCristian Stoica <cristian.stoica@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A call to of_iomap does not request the memory region. This patch adds the
function of_io_request_and_map which requests the memory region before
mapping it.
Signed-off-by: NMatthias Brugger <matthias.bgg@gmail.com>
Suggested-by: NThomas Gleixner <tglx@linutronix.de>
Suggested-by: NRob Herring <robh@kernel.org>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>

If the renamed symbol is defined lib/iomap.c implements ioport_map and
ioport_unmap and currently (nearly) all platforms define the port
accessor functions outb/inb and friend unconditionally.  So
HAS_IOPORT_MAP is the better name for this.

Consequently NO_IOPORT is renamed to NO_IOPORT_MAP.

The motivation for this change is to reintroduce a symbol HAS_IOPORT
that signals if outb/int et al are available.  I will address that at
least one merge window later though to keep surprises to a minimum and
catch new introductions of (HAS|NO)_IOPORT.

The changes in this commit were done using:

	$ git grep -l -E '(NO|HAS)_IOPORT' | xargs perl -p -i -e 's/\b((?:CONFIG_)?(?:NO|HAS)_IOPORT)\b/$1_MAP/'
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a assembler function on x86, so it should be visible.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1391845930-28580-2-git-send-email-ak@linux.intel.comSigned-off-by: NH. Peter Anvin <hpa@linux.intel.com>

Several drivers currently use mtrr_add through various #ifdef guards
and/or drm wrappers.  The vast majority of them want to add WC MTRRs
on x86 systems and don't actually need the MTRR if PAT (i.e.
ioremap_wc, etc) are working.

arch_phys_wc_add and arch_phys_wc_del are new functions, available
on all architectures and configurations, that add WC MTRRs on x86 if
needed (and handle errors) and do nothing at all otherwise.  They're
also easier to use than mtrr_add and mtrr_del, so the call sites can
be simplified.

As an added benefit, this will avoid wasting MTRRs and possibly
warning pointlessly on PAT-supporting systems.
Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Some power systems do not have legacy ISA devices. So, /dev/port is not
a valid interface on these systems. User level tools such as kbdrate is
trying to access the device using this interface which is causing the
system crash.

This patch will fix this issue by not creating this interface on these
powerpc systems.
Signed-off-by: NHaren Myneni <haren@us.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Current x86 ioremap() doesn't handle physical address higher than
32-bit properly in X86_32 PAE mode. When physical address higher than
32-bit is passed to ioremap(), higher 32-bits in physical address is
cleared wrongly. Due to this bug, ioremap() can map wrong address to
linear address space.

In my case, 64-bit MMIO region was assigned to a PCI device (ioat
device) on my system. Because of the ioremap()'s bug, wrong physical
address (instead of MMIO region) was mapped to linear address space.
Because of this, loading ioatdma driver caused unexpected behavior
(kernel panic, kernel hangup, ...).
Signed-off-by: NKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
LKML-Reference: <4C1AE680.7090408@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>

We provide an ioremap_flags, so this provides a corresponding
devm_ioremap_prot.  The slight name difference is at Ben
Herrenschmidt's request as he plans on changing ioremap_flags to
ioremap_prot in the future.
Signed-off-by: NEmil Medve <Emilian.Medve@Freescale.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Acked-by: NTejun Heo <htejun@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Use a resource_size_t instead of unsigned long since some arch's are
capable of having ioremap deal with addresses greater than the size of a
unsigned long.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>
Cc: Tejun Heo <htejun@gmail.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This is a rather bizarre thing to have inlined in io.h.  Stick it in lib/
instead.

While we're there, despaghetti it a bit, and fix its off-by-one behaviour when
passed a zero length.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

lib/ioremap.c is presently only built in if CONFIG_MMU is set.  While this
is reasonable, platforms that support both CONFIG_MMU=y or n need to be
able to call in to this regardless.

As none of the current nommu platforms do anything special with ioremap(),
we assume that it's always successful.

This fixes the SH-4 build with CONFIG_MMU=n.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Provide an dummy implementation of devm_ioport_map() and
devm_ioport_unmap() to allow drivers (eg, pata_platform) to build for
platforms where CONFIG_NO_IOPORT is selected.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* Split the implementation-agnostic stuff in separate files.
* Make sure that targets using non-default request_irq() pull
  kernel/irq/devres.o
* Introduce new symbols (HAS_IOPORT and HAS_IOMEM) defaulting to positive;
  allow architectures to turn them off (we needed these symbols anyway for
  dependencies of quite a few drivers).
* protect the ioport-related parts of lib/devres.o with CONFIG_HAS_IOPORT.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

In file included from drivers/infiniband/hw/ipath/ipath_diag.c:44:
include/linux/io.h:35: warning: 'struct device' declared inside parameter list
include/linux/io.h:35: warning: its scope is only this definition or declaration

Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement pcim_iomap_regions().  This function takes mask of BARs to
request and iomap.  No BAR should have length of zero.  BARs are
iomapped using pcim_iomap_table().
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

Implement device resource management, in short, devres.  A device
driver can allocate arbirary size of devres data which is associated
with a release function.  On driver detach, release function is
invoked on the devres data, then, devres data is freed.

devreses are typed by associated release functions.  Some devreses are
better represented by single instance of the type while others need
multiple instances sharing the same release function.  Both usages are
supported.

devreses can be grouped using devres group such that a device driver
can easily release acquired resources halfway through initialization
or selectively release resources (e.g. resources for port 1 out of 4
ports).

This patch adds devres core including documentation and the following
managed interfaces.

* alloc/free	: devm_kzalloc(), devm_kzfree()
* IO region	: devm_request_region(), devm_release_region()
* IRQ		: devm_request_irq(), devm_free_irq()
* DMA		: dmam_alloc_coherent(), dmam_free_coherent(),
		  dmam_declare_coherent_memory(), dmam_pool_create(),
		  dmam_pool_destroy()
* PCI		: pcim_enable_device(), pcim_pin_device(), pci_is_managed()
* iomap		: devm_ioport_map(), devm_ioport_unmap(), devm_ioremap(),
		  devm_ioremap_nocache(), devm_iounmap(), pcim_iomap_table(),
		  pcim_iomap(), pcim_iounmap()
Signed-off-by: NTejun Heo <htejun@gmail.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

There's nothing arch-specific about check_signature(), so move it to
<linux/io.h>.  Use a cross between the Alpha and i386 implementations as
the generic one.
Signed-off-by: NMatthew Wilcox <willy@parisc-linux.org>
Acked-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch adds a generic implementation of ioremap_page_range() in
lib/ioremap.c based on the i386 implementation. It differs from the
i386 version in the following ways:

  * The PTE flags are passed as a pgprot_t argument and must be
    determined up front by the arch-specific code. No additional
    PTE flags are added.
  * Uses set_pte_at() instead of set_pte()

[bunk@stusta.de: warning fix]
]dhowells@redhat.com: nommu build fix]
Signed-off-by: NHaavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Andi Kleen <ak@suse.de>
Cc: <linux-m32r@ml.linux-m32r.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Introduce __iowrite64_copy.  It will be used by the Myri-10G Ethernet
driver to post requests to the NIC.  This driver will be submitted soon.

__iowrite64_copy copies to I/O memory in units of 64 bits when possible (on
64 bit architectures).  It reverts to __iowrite32_copy on 32 bit
architectures.
Signed-off-by: NBrice Goglin <brice@myri.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This arch-independent routine copies data to a memory-mapped I/O region,
using 32-bit accesses.  The naming is double-underscored to make it clear
that it does not guarantee write ordering, nor does it perform a memory
barrier afterwards; the kernel doc also explicitly states this.  This style
of access is required by some devices.

This change also introduces include/linux/io.h, at Andrew's suggestion.  It
only has one occupant at the moment, but is a logical destination for
oft-replicated contents of include/asm-*/{io,iomap}.h to migrate to.
Signed-off-by: NBryan O'Sullivan <bos@pathscale.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>