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Автор SHA1 Сообщение Дата
Jonathan Corbet f58576666c x86/mm: Improve documentation for low-level device I/O functions
Add kerneldoc comments for memcpy_{to,from}io() and memset_io().  The
existing documentation for ioremap() was distant from the definition,
causing kernel-doc to miss it; move it appropriately.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170127161752.0b95e95b@lwn.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-01-28 09:37:51 +01:00
Dave Airlie 8ef4227615 x86/io: add interface to reserve io memtype for a resource range. (v1.1)
A recent change to the mm code in:
87744ab383 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: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2016-10-26 15:45:38 +10:00
Linus Torvalds 12f03ee606 libnvdimm for 4.3:
1/ Introduce ZONE_DEVICE and devm_memremap_pages() as a generic
    mechanism for adding device-driver-discovered memory regions to the
    kernel's direct map.  This facility is used by the pmem driver to
    enable pfn_to_page() operations on the page frames returned by DAX
    ('direct_access' in 'struct block_device_operations'). For now, the
    'memmap' allocation for these "device" pages comes from "System
    RAM".  Support for allocating the memmap from device memory will
    arrive in a later kernel.
 
 2/ Introduce memremap() to replace usages of ioremap_cache() and
    ioremap_wt().  memremap() drops the __iomem annotation for these
    mappings to memory that do not have i/o side effects.  The
    replacement of ioremap_cache() with memremap() is limited to the
    pmem driver to ease merging the api change in v4.3.  Completion of
    the conversion is targeted for v4.4.
 
 3/ Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem
    driver, update the VFS DAX implementation and PMEM api to provide
    persistence guarantees for kernel operations on a DAX mapping.
 
 4/ Convert the ACPI NFIT 'BLK' driver to map the block apertures as
    cacheable to improve performance.
 
 5/ Miscellaneous updates and fixes to libnvdimm including support
    for issuing "address range scrub" commands, clarifying the optimal
    'sector size' of pmem devices, a clarification of the usage of the
    ACPI '_STA' (status) property for DIMM devices, and other minor
    fixes.
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Merge tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "This update has successfully completed a 0day-kbuild run and has
  appeared in a linux-next release.  The changes outside of the typical
  drivers/nvdimm/ and drivers/acpi/nfit.[ch] paths are related to the
  removal of IORESOURCE_CACHEABLE, the introduction of memremap(), and
  the introduction of ZONE_DEVICE + devm_memremap_pages().

  Summary:

   - Introduce ZONE_DEVICE and devm_memremap_pages() as a generic
     mechanism for adding device-driver-discovered memory regions to the
     kernel's direct map.

     This facility is used by the pmem driver to enable pfn_to_page()
     operations on the page frames returned by DAX ('direct_access' in
     'struct block_device_operations').

     For now, the 'memmap' allocation for these "device" pages comes
     from "System RAM".  Support for allocating the memmap from device
     memory will arrive in a later kernel.

   - Introduce memremap() to replace usages of ioremap_cache() and
     ioremap_wt().  memremap() drops the __iomem annotation for these
     mappings to memory that do not have i/o side effects.  The
     replacement of ioremap_cache() with memremap() is limited to the
     pmem driver to ease merging the api change in v4.3.

     Completion of the conversion is targeted for v4.4.

   - Similar to the usage of memcpy_to_pmem() + wmb_pmem() in the pmem
     driver, update the VFS DAX implementation and PMEM api to provide
     persistence guarantees for kernel operations on a DAX mapping.

   - Convert the ACPI NFIT 'BLK' driver to map the block apertures as
     cacheable to improve performance.

   - Miscellaneous updates and fixes to libnvdimm including support for
     issuing "address range scrub" commands, clarifying the optimal
     'sector size' of pmem devices, a clarification of the usage of the
     ACPI '_STA' (status) property for DIMM devices, and other minor
     fixes"

* tag 'libnvdimm-for-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (34 commits)
  libnvdimm, pmem: direct map legacy pmem by default
  libnvdimm, pmem: 'struct page' for pmem
  libnvdimm, pfn: 'struct page' provider infrastructure
  x86, pmem: clarify that ARCH_HAS_PMEM_API implies PMEM mapped WB
  add devm_memremap_pages
  mm: ZONE_DEVICE for "device memory"
  mm: move __phys_to_pfn and __pfn_to_phys to asm/generic/memory_model.h
  dax: drop size parameter to ->direct_access()
  nd_blk: change aperture mapping from WC to WB
  nvdimm: change to use generic kvfree()
  pmem, dax: have direct_access use __pmem annotation
  dax: update I/O path to do proper PMEM flushing
  pmem: add copy_from_iter_pmem() and clear_pmem()
  pmem, x86: clean up conditional pmem includes
  pmem: remove layer when calling arch_has_wmb_pmem()
  pmem, x86: move x86 PMEM API to new pmem.h header
  libnvdimm, e820: make CONFIG_X86_PMEM_LEGACY a tristate option
  pmem: switch to devm_ allocations
  devres: add devm_memremap
  libnvdimm, btt: write and validate parent_uuid
  ...
2015-09-08 14:35:59 -07:00
Ross Zwisler 67a3e8fe90 nd_blk: change aperture mapping from WC to WB
This should result in a pretty sizeable performance gain for reads.  For
rough comparison I did some simple read testing using PMEM to compare
reads of write combining (WC) mappings vs write-back (WB).  This was
done on a random lab machine.

PMEM reads from a write combining mapping:
	# dd of=/dev/null if=/dev/pmem0 bs=4096 count=100000
	100000+0 records in
	100000+0 records out
	409600000 bytes (410 MB) copied, 9.2855 s, 44.1 MB/s

PMEM reads from a write-back mapping:
	# dd of=/dev/null if=/dev/pmem0 bs=4096 count=1000000
	1000000+0 records in
	1000000+0 records out
	4096000000 bytes (4.1 GB) copied, 3.44034 s, 1.2 GB/s

To be able to safely support a write-back aperture I needed to add
support for the "read flush" _DSM flag, as outlined in the DSM spec:

http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

This flag tells the ND BLK driver that it needs to flush the cache lines
associated with the aperture after the aperture is moved but before any
new data is read.  This ensures that any stale cache lines from the
previous contents of the aperture will be discarded from the processor
cache, and the new data will be read properly from the DIMM.  We know
that the cache lines are clean and will be discarded without any
writeback because either a) the previous aperture operation was a read,
and we never modified the contents of the aperture, or b) the previous
aperture operation was a write and we must have written back the dirtied
contents of the aperture to the DIMM before the I/O was completed.

In order to add support for the "read flush" flag I needed to add a
generic routine to invalidate cache lines, mmio_flush_range().  This is
protected by the ARCH_HAS_MMIO_FLUSH Kconfig variable, and is currently
only supported on x86.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-27 19:38:28 -04:00
Ingo Molnar 8d58b66ed2 Linux 4.2-rc8
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Merge tag 'v4.2-rc8' into x86/mm, before applying new changes

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-08-25 09:59:19 +02:00
Dan Williams e836a256e8 pmem: convert to generic memremap
Kill arch_memremap_pmem() and just let the architecture specify the
flags to be passed to memremap().  Default to writethrough by default.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-08-14 13:23:28 -04:00
Luis R. Rodriguez 8c7ea50c01 x86/mm, asm-generic: Add IOMMU ioremap_uc() variant default
We currently have no safe way of currently defining architecture
agnostic IOMMU ioremap_*() variants. The trend is for folks to
*assume* that ioremap_nocache() should be the default everywhere
and then add this mapping on each architectures -- this is not
correct today for a variety of reasons.

We have two options:

  1) Sit and wait for every architecture in Linux to get a
     an ioremap_*() variant defined before including it upstream.

  2) Gather consensus on a safe architecture agnostic ioremap_*()
     default.

Approach 1) introduces development latencies, and since 2) will
take time and work on clarifying semantics the only remaining
sensible thing to do to avoid issues is returning NULL on
ioremap_*() variants.

In order for this to work we must have all architectures declare
their own ioremap_*() variants as defined. This will take some
work, do this for ioremp_uc() to set the example as its only
currently implemented on x86. Document all this.

We only provide implementation support for ioremap_uc() as the
other ioremap_*() variants are well defined all over the kernel
for other architectures already.

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: benh@kernel.crashing.org
Cc: bp@suse.de
Cc: dan.j.williams@intel.com
Cc: geert@linux-m68k.org
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: linux-mm@kvack.org
Cc: luto@amacapital.net
Cc: mpe@ellerman.id.au
Cc: mst@redhat.com
Cc: ralf@linux-mips.org
Cc: ross.zwisler@linux.intel.com
Cc: stefan.bader@canonical.com
Cc: tj@kernel.org
Cc: tomi.valkeinen@ti.com
Cc: toshi.kani@hp.com
Link: http://lkml.kernel.org/r/1436488096-3165-1-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-07-21 10:47:03 +02:00
Linus Torvalds 88793e5c77 The libnvdimm sub-system introduces, in addition to the libnvdimm-core,
4 drivers / enabling modules:
 
 NFIT:
 Instantiates an "nvdimm bus" with the core and registers memory devices
 (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware Interface
 table).  After registering NVDIMMs the NFIT driver then registers
 "region" devices.  A libnvdimm-region defines an access mode and the
 boundaries of persistent memory media.  A region may span multiple
 NVDIMMs that are interleaved by the hardware memory controller.  In
 turn, a libnvdimm-region can be carved into a "namespace" device and
 bound to the PMEM or BLK driver which will attach a Linux block device
 (disk) interface to the memory.
 
 PMEM:
 Initially merged in v4.1 this driver for contiguous spans of persistent
 memory address ranges is re-worked to drive PMEM-namespaces emitted by
 the libnvdimm-core.  In this update the PMEM driver, on x86, gains the
 ability to assert that writes to persistent memory have been flushed all
 the way through the caches and buffers in the platform to persistent
 media.  See memcpy_to_pmem() and wmb_pmem().
 
 BLK:
 This new driver enables access to persistent memory media through "Block
 Data Windows" as defined by the NFIT.  The primary difference of this
 driver to PMEM is that only a small window of persistent memory is
 mapped into system address space at any given point in time.  Per-NVDIMM
 windows are reprogrammed at run time, per-I/O, to access different
 portions of the media.  BLK-mode, by definition, does not support DAX.
 
 BTT:
 This is a library, optionally consumed by either PMEM or BLK, that
 converts a byte-accessible namespace into a disk with atomic sector
 update semantics (prevents sector tearing on crash or power loss).  The
 sinister aspect of sector tearing is that most applications do not know
 they have a atomic sector dependency.  At least today's disk's rarely
 ever tear sectors and if they do one almost certainly gets a CRC error
 on access.  NVDIMMs will always tear and always silently.  Until an
 application is audited to be robust in the presence of sector-tearing
 the usage of BTT is recommended.
 
 Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig,
 Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox,
 Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael
 Wysocki, and Bob Moore.
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Merge tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm

Pull libnvdimm subsystem from Dan Williams:
 "The libnvdimm sub-system introduces, in addition to the
  libnvdimm-core, 4 drivers / enabling modules:

  NFIT:
    Instantiates an "nvdimm bus" with the core and registers memory
    devices (NVDIMMs) enumerated by the ACPI 6.0 NFIT (NVDIMM Firmware
    Interface table).

    After registering NVDIMMs the NFIT driver then registers "region"
    devices.  A libnvdimm-region defines an access mode and the
    boundaries of persistent memory media.  A region may span multiple
    NVDIMMs that are interleaved by the hardware memory controller.  In
    turn, a libnvdimm-region can be carved into a "namespace" device and
    bound to the PMEM or BLK driver which will attach a Linux block
    device (disk) interface to the memory.

  PMEM:
    Initially merged in v4.1 this driver for contiguous spans of
    persistent memory address ranges is re-worked to drive
    PMEM-namespaces emitted by the libnvdimm-core.

    In this update the PMEM driver, on x86, gains the ability to assert
    that writes to persistent memory have been flushed all the way
    through the caches and buffers in the platform to persistent media.
    See memcpy_to_pmem() and wmb_pmem().

  BLK:
    This new driver enables access to persistent memory media through
    "Block Data Windows" as defined by the NFIT.  The primary difference
    of this driver to PMEM is that only a small window of persistent
    memory is mapped into system address space at any given point in
    time.

    Per-NVDIMM windows are reprogrammed at run time, per-I/O, to access
    different portions of the media.  BLK-mode, by definition, does not
    support DAX.

  BTT:
    This is a library, optionally consumed by either PMEM or BLK, that
    converts a byte-accessible namespace into a disk with atomic sector
    update semantics (prevents sector tearing on crash or power loss).

    The sinister aspect of sector tearing is that most applications do
    not know they have a atomic sector dependency.  At least today's
    disk's rarely ever tear sectors and if they do one almost certainly
    gets a CRC error on access.  NVDIMMs will always tear and always
    silently.  Until an application is audited to be robust in the
    presence of sector-tearing the usage of BTT is recommended.

  Thanks to: Ross Zwisler, Jeff Moyer, Vishal Verma, Christoph Hellwig,
  Ingo Molnar, Neil Brown, Boaz Harrosh, Robert Elliott, Matthew Wilcox,
  Andy Rudoff, Linda Knippers, Toshi Kani, Nicholas Moulin, Rafael
  Wysocki, and Bob Moore"

* tag 'libnvdimm-for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/nvdimm: (33 commits)
  arch, x86: pmem api for ensuring durability of persistent memory updates
  libnvdimm: Add sysfs numa_node to NVDIMM devices
  libnvdimm: Set numa_node to NVDIMM devices
  acpi: Add acpi_map_pxm_to_online_node()
  libnvdimm, nfit: handle unarmed dimms, mark namespaces read-only
  pmem: flag pmem block devices as non-rotational
  libnvdimm: enable iostat
  pmem: make_request cleanups
  libnvdimm, pmem: fix up max_hw_sectors
  libnvdimm, blk: add support for blk integrity
  libnvdimm, btt: add support for blk integrity
  fs/block_dev.c: skip rw_page if bdev has integrity
  libnvdimm: Non-Volatile Devices
  tools/testing/nvdimm: libnvdimm unit test infrastructure
  libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory
  nd_btt: atomic sector updates
  libnvdimm: infrastructure for btt devices
  libnvdimm: write blk label set
  libnvdimm: write pmem label set
  libnvdimm: blk labels and namespace instantiation
  ...
2015-06-29 10:34:42 -07:00
Ross Zwisler 61031952f4 arch, x86: pmem api for ensuring durability of persistent memory updates
Based on an original patch by Ross Zwisler [1].

Writes to persistent memory have the potential to be posted to cpu
cache, cpu write buffers, and platform write buffers (memory controller)
before being committed to persistent media.  Provide apis,
memcpy_to_pmem(), wmb_pmem(), and memremap_pmem(), to write data to
pmem and assert that it is durable in PMEM (a persistent linear address
range).  A '__pmem' attribute is added so sparse can track proper usage
of pointers to pmem.

This continues the status quo of pmem being x86 only for 4.2, but
reworks to ioremap, and wider implementation of memremap() will enable
other archs in 4.3.

[1]: https://lists.01.org/pipermail/linux-nvdimm/2015-May/000932.html

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
[djbw: various reworks]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2015-06-26 11:23:38 -04:00
Toshi Kani d838270e25 x86/mm, asm-generic: Add ioremap_wt() for creating Write-Through mappings
Add ioremap_wt() for creating Write-Through mappings on x86. It
follows the same model as ioremap_wc() for multi-arch support.
Define ARCH_HAS_IOREMAP_WT in the x86 version of io.h to
indicate that ioremap_wt() is implemented on x86.

Also update the PAT documentation file to cover ioremap_wt().

Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Elliott@hp.com
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: arnd@arndb.de
Cc: hch@lst.de
Cc: hmh@hmh.eng.br
Cc: jgross@suse.com
Cc: konrad.wilk@oracle.com
Cc: linux-mm <linux-mm@kvack.org>
Cc: linux-nvdimm@lists.01.org
Cc: stefan.bader@canonical.com
Cc: yigal@plexistor.com
Link: http://lkml.kernel.org/r/1433436928-31903-8-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-06-07 15:28:56 +02:00
Stephen Rothwell d6472302f2 x86/mm: Decouple <linux/vmalloc.h> from <asm/io.h>
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: David Miller <davem@davemloft.net>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
[ Tidied up the changelog. ]
Acked-by: David Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Vinod 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: Ingo Molnar <mingo@kernel.org>
2015-06-03 12:02:00 +02:00
Luis R. Rodriguez 7d010fdf29 x86/mm/mtrr: Avoid #ifdeffery with phys_wc_to_mtrr_index()
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: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav 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.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-27 14:41:00 +02:00
Luis R. Rodriguez e4b6be33c2 x86/mm: Add ioremap_uc() helper to map memory uncacheable (not UC-)
ioremap_nocache() currently uses UC- by default. Our goal is to
eventually make UC the default. Linux maps UC- to PCD=1, PWT=0
page attributes on non-PAT systems. Linux maps UC to PCD=1,
PWT=1 page attributes on non-PAT systems. On non-PAT and PAT
systems a WC MTRR has different effects on pages with either of
these attributes. In order to help with a smooth transition its
best to enable use of UC (PCD,1, PWT=1) on a region as that
ensures a WC MTRR will have no effect on a region, this however
requires us to have an way to declare a region as UC and we
currently do not have a way to do this.

  WC MTRR on non-PAT system with PCD=1, PWT=0 (UC-) yields WC.
  WC MTRR on non-PAT system with PCD=1, PWT=1 (UC)  yields UC.

  WC MTRR on PAT system with PCD=1, PWT=0 (UC-) yields WC.
  WC MTRR on PAT system with PCD=1, PWT=1 (UC)  yields UC.

A flip of the default ioremap_nocache() behaviour from UC- to UC
can therefore regress a memory region from effective memory type
WC to UC if MTRRs are used. Use of MTRRs should be phased out
and in the best case only arch_phys_wc_add() use will remain,
even if this happens arch_phys_wc_add() will have an effect on
non-PAT systems and changes to default ioremap_nocache()
behaviour could regress drivers.

Now, ideally we'd use ioremap_nocache() on the regions in which
we'd need uncachable memory types and avoid any MTRRs on those
regions. There are however some restrictions on MTRRs use, such
as the requirement of having the base and size of variable sized
MTRRs to be powers of two, which could mean having to use a WC
MTRR over a large area which includes a region in which
write-combining effects are undesirable.

Add ioremap_uc() to help with the both phasing out of MTRR use
and also provide a way to blacklist small WC undesirable regions
in devices with mixed regions which are size-implicated to use
large WC MTRRs. Use of ioremap_uc() helps phase out MTRR use by
avoiding regressions with an eventual flip of default behaviour
or ioremap_nocache() from UC- to UC.

Drivers working with WC MTRRs can use the below table to review
and consider the use of ioremap*() and similar helpers to ensure
appropriate behaviour long term even if default
ioremap_nocache() behaviour changes from UC- to UC.

Although ioremap_uc() is being added we leave set_memory_uc() to
use UC- as only initial memory type setup is required to be able
to accommodate existing device drivers and phase out MTRR use.
It should also be clarified that set_memory_uc() cannot be used
with IO memory, even though its use will not return any errors,
it really has no effect.

  ----------------------------------------------------------------------
  MTRR Non-PAT   PAT    Linux ioremap value        Effective memory type
  ----------------------------------------------------------------------
                                                    Non-PAT |  PAT
       PAT
       |PCD
       ||PWT
       |||
  WC   000      WB      _PAGE_CACHE_MODE_WB            WC   |   WC
  WC   001      WC      _PAGE_CACHE_MODE_WC            WC*  |   WC
  WC   010      UC-     _PAGE_CACHE_MODE_UC_MINUS      WC*  |   WC
  WC   011      UC      _PAGE_CACHE_MODE_UC            UC   |   UC
  ----------------------------------------------------------------------

Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Antonino Daplas <adaplas@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Denys Vlasenko <dvlasenk@redhat.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: Mike Travis <travis@sgi.com>
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: linux-fbdev@vger.kernel.org
Link: http://lkml.kernel.org/r/1430343851-967-2-git-send-email-mcgrof@do-not-panic.com
Link: http://lkml.kernel.org/r/1431332153-18566-9-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-11 10:38:45 +02:00
Linus Torvalds a023748d53 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm tree changes from Ingo Molnar:
 "The biggest change is full PAT support from Jürgen Gross:

     The x86 architecture offers via the PAT (Page Attribute Table) a
     way to specify different caching modes in page table entries.  The
     PAT MSR contains 8 entries each specifying one of 6 possible cache
     modes.  A pte references one of those entries via 3 bits:
     _PAGE_PAT, _PAGE_PWT and _PAGE_PCD.

     The Linux kernel currently supports only 4 different cache modes.
     The PAT MSR is set up in a way that the setting of _PAGE_PAT in a
     pte doesn't matter: the top 4 entries in the PAT MSR are the same
     as the 4 lower entries.

     This results in the kernel not supporting e.g. write-through mode.
     Especially this cache mode would speed up drivers of video cards
     which now have to use uncached accesses.

     OTOH some old processors (Pentium) don't support PAT correctly and
     the Xen hypervisor has been using a different PAT MSR configuration
     for some time now and can't change that as this setting is part of
     the ABI.

     This patch set abstracts the cache mode from the pte and introduces
     tables to translate between cache mode and pte bits (the default
     cache mode "write back" is hard-wired to PAT entry 0).  The tables
     are statically initialized with values being compatible to old
     processors and current usage.  As soon as the PAT MSR is changed
     (or - in case of Xen - is read at boot time) the tables are changed
     accordingly.  Requests of mappings with special cache modes are
     always possible now, in case they are not supported there will be a
     fallback to a compatible but slower mode.

     Summing it up, this patch set adds the following features:

      - capability to support WT and WP cache modes on processors with
        full PAT support

      - processors with no or uncorrect PAT support are still working as
        today, even if WT or WP cache mode are selected by drivers for
        some pages

      - reduction of Xen special handling regarding cache mode

  Another change is a boot speedup on ridiculously large RAM systems,
  plus other smaller fixes"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  x86: mm: Move PAT only functions to mm/pat.c
  xen: Support Xen pv-domains using PAT
  x86: Enable PAT to use cache mode translation tables
  x86: Respect PAT bit when copying pte values between large and normal pages
  x86: Support PAT bit in pagetable dump for lower levels
  x86: Clean up pgtable_types.h
  x86: Use new cache mode type in memtype related functions
  x86: Use new cache mode type in mm/ioremap.c
  x86: Use new cache mode type in setting page attributes
  x86: Remove looking for setting of _PAGE_PAT_LARGE in pageattr.c
  x86: Use new cache mode type in track_pfn_remap() and track_pfn_insert()
  x86: Use new cache mode type in mm/iomap_32.c
  x86: Use new cache mode type in asm/pgtable.h
  x86: Use new cache mode type in arch/x86/mm/init_64.c
  x86: Use new cache mode type in arch/x86/pci
  x86: Use new cache mode type in drivers/video/fbdev/vermilion
  x86: Use new cache mode type in drivers/video/fbdev/gbefb.c
  x86: Use new cache mode type in include/asm/fb.h
  x86: Make page cache mode a real type
  x86: mm: Use 2GB memory block size on large-memory x86-64 systems
  ...
2014-12-10 13:59:34 -08:00
Juergen Gross b14097bd91 x86: Use new cache mode type in mm/ioremap.c
Instead of directly using the cache mode bits in the pte switch to
using the cache mode type.

Based-on-patch-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stefan.bader@canonical.com
Cc: xen-devel@lists.xensource.com
Cc: konrad.wilk@oracle.com
Cc: ville.syrjala@linux.intel.com
Cc: david.vrabel@citrix.com
Cc: jbeulich@suse.com
Cc: toshi.kani@hp.com
Cc: plagnioj@jcrosoft.com
Cc: tomi.valkeinen@ti.com
Cc: bhelgaas@google.com
Link: http://lkml.kernel.org/r/1415019724-4317-13-git-send-email-jgross@suse.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-16 11:04:26 +01:00
Arnd Bergmann 1c8d29696f Merge branch 'io' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into asm-generic
* 'io' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux:
  documentation: memory-barriers: clarify relaxed io accessor semantics
  x86: io: implement dummy relaxed accessor macros for writes
  tile: io: implement dummy relaxed accessor macros for writes
  sparc: io: implement dummy relaxed accessor macros for writes
  powerpc: io: implement dummy relaxed accessor macros for writes
  parisc: io: implement dummy relaxed accessor macros for writes
  mn10300: io: implement dummy relaxed accessor macros for writes
  m68k: io: implement dummy relaxed accessor macros for writes
  m32r: io: implement dummy relaxed accessor macros for writes
  ia64: io: implement dummy relaxed accessor macros for writes
  cris: io: implement dummy relaxed accessor macros for writes
  frv: io: implement dummy relaxed accessor macros for writes
  xtensa: io: remove dummy relaxed accessor macros for reads
  s390: io: remove dummy relaxed accessor macros for reads
  microblaze: io: remove dummy relaxed accessor macros
  asm-generic: io: implement relaxed accessor macros as conditional wrappers

Conflicts:
	include/asm-generic/io.h

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2014-11-11 19:55:45 +01:00
Thierry Reding 4707a341b4 /dev/mem: Use more consistent data types
The xlate_dev_{kmem,mem}_ptr() functions take either a physical address
or a kernel virtual address, so data types should be phys_addr_t and
void *. They both return a kernel virtual address which is only ever
used in calls to copy_{from,to}_user(), so make variables that store it
void * rather than char * for consistency.

Also only define a weak unxlate_dev_mem_ptr() function if architectures
haven't overridden them in the asm/io.h header file.

Signed-off-by: Thierry Reding <treding@nvidia.com>
2014-11-10 15:59:21 +01:00
Will Deacon cbc908ef8e x86: io: implement dummy relaxed accessor macros for writes
write{b,w,l,q}_relaxed are implemented by some architectures in order to
permit memory-mapped I/O accesses with weaker barrier semantics than the
non-relaxed variants.

This patch adds dummy macros for the write accessors to x86, in the
same vein as the dummy definitions for the relaxed read accessors.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-10-20 18:49:18 +01:00
Mark Salter 5b7c73e009 x86: use generic early_ioremap
Move x86 over to the generic early ioremap implementation.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:15 -07:00
Dave Young 6b550f6f20 x86/mm: sparse warning fix for early_memremap
This patch series takes the common bits from the x86 early ioremap
implementation and creates a generic implementation which may be used by
other architectures.  The early ioremap interfaces are intended for
situations where boot code needs to make temporary virtual mappings
before the normal ioremap interfaces are available.  Typically, this
means before paging_init() has run.

This patch (of 6):

There's a lot of sparse warnings for code like below: void *a =
early_memremap(phys_addr, size);

early_memremap intend to map kernel memory with ioremap facility, the
return pointer should be a kernel ram pointer instead of iomem one.

For making the function clearer and supressing sparse warnings this patch
do below two things:
1. cast to (__force void *) for the return value of early_memremap
2. add early_memunmap function and pass (__force void __iomem *) to iounmap

From Boris:
  "Ingo told me yesterday, it makes sense too.  I'd guess we can try it.
   FWIW, all callers of early_memremap use the memory they get remapped
   as normal memory so we should be safe"

Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <borislav.petkov@amd.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07 16:36:14 -07:00
Dave Jones 09df7c4c80 x86: Remove CONFIG_X86_OOSTORE
This was an optimization that made memcpy type benchmarks a little
faster on ancient (Circa 1998) IDT Winchip CPUs.  In real-life
workloads, it wasn't even noticable, and I doubt anyone is running
benchmarks on 16 year old silicon any more.

Given this code has likely seen very little use over the last decade,
let's just remove it.

Signed-off-by: Dave Jones <davej@fedoraproject.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-03-11 10:16:18 -07:00
Andy Lutomirski d0d98eedee Add arch_phys_wc_{add, del} to manipulate WC MTRRs if needed
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: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-05-31 13:02:52 +10:00
Linus Torvalds 33f35f2a4e x86: don't include xen/xen.h in <asm/io.h> unless XEN is enabled
Dmitry Kasatkin reports:
  "kernel-devel package with kernel headers have no <include/xen>
   directory if XEN is disabled.  Modules which inclide asm/io.h won't
   compile.

   XEN related content is behind the CONFIG_XEN flag in the io.h.  And
   <xen/xen.h> should be also behind CONFIG_XEN flag."

So move the include of <xen/xen.h> down into the section that is
conditional on CONFIG_XEN.

Reported-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-03 22:00:38 -10:00
Roland Dreier dbee8a0aff x86: remove 32-bit versions of readq()/writeq()
The presense of a writeq() implementation on 32-bit x86 that splits the
64-bit write into two 32-bit writes turns out to break the mpt2sas driver
(and in general is risky for drivers as was discussed in
<http://lkml.kernel.org/r/adaab6c1h7c.fsf@cisco.com>).  To fix this,
revert 2c5643b1c5 ("x86: provide readq()/writeq() on 32-bit too") and
follow-on cleanups.

This unfortunately leads to pushing non-atomic definitions of readq() and
write() to various x86-only drivers that in the meantime started using the
definitions in the x86 version of <asm/io.h>.  However as discussed
exhaustively, this is actually the right thing to do, because the right
way to split a 64-bit transaction is hardware dependent and therefore
belongs in the hardware driver (eg mpt2sas needs a spinlock to make sure
no other accesses occur in between the two halves of the access).

Build tested on 32- and 64-bit x86 allmodconfig.

Link: http://lkml.kernel.org/r/x86-32-writeq-is-broken@mdm.bga.com
Acked-by: Hitoshi Mitake <h.mitake@gmail.com>
Cc: Kashyap Desai <Kashyap.Desai@lsi.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Ravi Anand <ravi.anand@qlogic.com>
Cc: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Cc: Matthew Garrett <mjg@redhat.com>
Cc: Jason Uhlenkott <juhlenko@akamai.com>
Acked-by: James Bottomley <James.Bottomley@parallels.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25 08:39:44 -07:00
Linus Torvalds 18cb657ca1 Merge branch 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen
and branch 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm

* 'for-linus' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
  xen: register xen pci notifier
  xen: initialize cpu masks for pv guests in xen_smp_init
  xen: add a missing #include to arch/x86/pci/xen.c
  xen: mask the MTRR feature from the cpuid
  xen: make hvc_xen console work for dom0.
  xen: add the direct mapping area for ISA bus access
  xen: Initialize xenbus for dom0.
  xen: use vcpu_ops to setup cpu masks
  xen: map a dummy page for local apic and ioapic in xen_set_fixmap
  xen: remap MSIs into pirqs when running as initial domain
  xen: remap GSIs as pirqs when running as initial domain
  xen: introduce XEN_DOM0 as a silent option
  xen: map MSIs into pirqs
  xen: support GSI -> pirq remapping in PV on HVM guests
  xen: add xen hvm acpi_register_gsi variant
  acpi: use indirect call to register gsi in different modes
  xen: implement xen_hvm_register_pirq
  xen: get the maximum number of pirqs from xen
  xen: support pirq != irq

* 'stable/xen-pcifront-0.8.2' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen: (27 commits)
  X86/PCI: Remove the dependency on isapnp_disable.
  xen: Update Makefile with CONFIG_BLOCK dependency for biomerge.c
  MAINTAINERS: Add myself to the Xen Hypervisor Interface and remove Chris Wright.
  x86: xen: Sanitse irq handling (part two)
  swiotlb-xen: On x86-32 builts, select SWIOTLB instead of depending on it.
  MAINTAINERS: Add myself for Xen PCI and Xen SWIOTLB maintainer.
  xen/pci: Request ACS when Xen-SWIOTLB is activated.
  xen-pcifront: Xen PCI frontend driver.
  xenbus: prevent warnings on unhandled enumeration values
  xenbus: Xen paravirtualised PCI hotplug support.
  xen/x86/PCI: Add support for the Xen PCI subsystem
  x86: Introduce x86_msi_ops
  msi: Introduce default_[teardown|setup]_msi_irqs with fallback.
  x86/PCI: Export pci_walk_bus function.
  x86/PCI: make sure _PAGE_IOMAP it set on pci mappings
  x86/PCI: Clean up pci_cache_line_size
  xen: fix shared irq device passthrough
  xen: Provide a variant of xen_poll_irq with timeout.
  xen: Find an unbound irq number in reverse order (high to low).
  xen: statically initialize cpu_evtchn_mask_p
  ...

Fix up trivial conflicts in drivers/pci/Makefile
2010-10-28 17:11:17 -07:00
Linus Torvalds 3044100e58 Merge branch 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits)
  x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S
  xen: Cope with unmapped pages when initializing kernel pagetable
  memblock, bootmem: Round pfn properly for memory and reserved regions
  memblock: Annotate memblock functions with __init_memblock
  memblock: Allow memblock_init to be called early
  memblock/arm: Fix memblock_region_is_memory() typo
  x86, memblock: Remove __memblock_x86_find_in_range_size()
  memblock: Fix wraparound in find_region()
  x86-32, memblock: Make add_highpages honor early reserved ranges
  x86, memblock: Fix crashkernel allocation
  arm, memblock: Fix the sparsemem build
  memblock: Fix section mismatch warnings
  powerpc, memblock: Fix memblock API change fallout
  memblock, microblaze: Fix memblock API change fallout
  x86: Remove old bootmem code
  x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve
  x86: Remove not used early_res code
  x86, memblock: Replace e820_/_early string with memblock_
  x86: Use memblock to replace early_res
  x86, memblock: Use memblock_debug to control debug message print out
  ...

Fix up trivial conflicts in arch/x86/kernel/setup.c and kernel/Makefile
2010-10-21 18:52:11 -07:00
Jeremy Fitzhardinge d8e0420603 xen: define BIOVEC_PHYS_MERGEABLE()
Impact: allow Xen control of bio merging

When running in Xen domain with device access, we need to make sure
the block subsystem doesn't merge requests across pages which aren't
machine physically contiguous.  To do this, we define our own
BIOVEC_PHYS_MERGEABLE.  When CONFIG_XEN isn't enabled, or we're not
running in a Xen domain, this has identical behaviour to the normal
implementation.  When running under Xen, we also make sure the
underlying machine pages are the same or adjacent.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2010-10-18 10:40:28 -04:00
Jeremy Fitzhardinge fef5ba7979 xen: Cope with unmapped pages when initializing kernel pagetable
Xen requires that all pages containing pagetable entries to be mapped
read-only.  If pages used for the initial pagetable are already mapped
then we can change the mapping to RO.  However, if they are initially
unmapped, we need to make sure that when they are later mapped, they
are also mapped RO.

We do this by knowing that the kernel pagetable memory is pre-allocated
in the range e820_table_start - e820_table_end, so any pfn within this
range should be mapped read-only.  However, the pagetable setup code
early_ioremaps the pages to write their entries, so we must make sure
that mappings created in the early_ioremap fixmap area are mapped RW.
(Those mappings are removed before the pages are presented to Xen
as pagetable pages.)

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
LKML-Reference: <4CB63A80.8060702@goop.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-10-13 16:07:13 -07:00
Cliff Wickman 3ee48b6af4 mm, x86: Saving vmcore with non-lazy freeing of vmas
During the reading of /proc/vmcore the kernel is doing
ioremap()/iounmap() repeatedly. And the buildup of un-flushed
vm_area_struct's is causing a great deal of overhead. (rb_next()
is chewing up most of that time).

This solution is to provide function set_iounmap_nonlazy(). It
causes a subsequent call to iounmap() to immediately purge the
vma area (with try_purge_vmap_area_lazy()).

With this patch we have seen the time for writing a 250MB
compressed dump drop from 71 seconds to 44 seconds.

Signed-off-by: Cliff Wickman <cpw@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: kexec@lists.infradead.org
Cc: <stable@kernel.org>
LKML-Reference: <E1OwHZ4-0005WK-Tw@eag09.americas.sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-17 09:11:56 +02:00
Liang Li e67a807f3d x86: Fix 'reservetop=' functionality
When specifying the 'reservetop=0xbadc0de' kernel parameter,
the kernel will stop booting due to a early_ioremap bug that
relates to commit 8827247ff.

The root cause of boot failure problem is the value of
'slot_virt[i]' was initialized in setup_arch->early_ioremap_init().
But later in setup_arch, the function 'parse_early_param' will
modify 'FIXADDR_TOP' when 'reservetop=0xbadc0de' being specified.

The simplest fix might be use __fix_to_virt(idx0) to get updated
value of 'FIXADDR_TOP' in '__early_ioremap' instead of reference
old value from slot_virt[slot] directly.

Changelog since v0:

-v1: When reservetop being handled then FIXADDR_TOP get
     adjusted, Hence check prev_map then re-initialize slot_virt and
     PMD based on new FIXADDR_TOP.

-v2: place fixup_early_ioremap hence call early_ioremap_init in
     reserve_top_address  to re-initialize slot_virt and
     corresponding PMD when parse_reservertop

-v3: move fixup_early_ioremap out of reserve_top_address to make
     sure other clients of reserve_top_address like xen/lguest won't
     broken

Signed-off-by: Liang Li <liang.li@windriver.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Wang Chen <wangchen@cn.fujitsu.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <1272621711-8683-1-git-send-email-liang.li@windriver.com>
[ fixed three small cleanliness details in fixup_early_ioremap() ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-30 12:19:53 +02:00
Brian Gerst 1c5b9069e1 x86: Merge io.h
io_32.h and io_64.h are now identical.  Merge them into io.h.

Signed-off-by: Brian Gerst <brgerst@gmail.com>
LKML-Reference: <1265380629-3212-8-git-send-email-brgerst@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-05 13:57:40 -08:00
Masami Hiramatsu 9b987aeb4a x86: fix set_fixmap to use phys_addr_t
Impact: fix kprobes crash on 32-bit with RAM above 4G

Use phys_addr_t for receiving a physical address argument
instead of unsigned long. This allows fixmap to handle
pages higher than 4GB on x86-32.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: systemtap-ml <systemtap@sources.redhat.com>
Cc: Gary Hade <garyhade@us.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <49DE3695.6040800@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-10 20:27:13 +02:00
Jeremy Fitzhardinge 4e8304758c x86: remove vestigial fix_ioremap prototypes
The function seems to have disappeared at some point, leaving
some vestigial prototypes behind...

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-04 02:29:32 +01:00
H. Peter Anvin a7eb518998 x86: truncate ISA addresses to unsigned int
Impact: Cleanup; fix inappropriate macro use

ISA addresses on x86 are mapped 1:1 with the physical address space.
Since the ISA address space is only 24 bits (32 for VLB or LPC) it
will always fit in an unsigned int, and at least in the aha1542 driver
using a wider type would cause an undesirable promotion.  Hence
explicitly cast the ISA bus addresses to unsigned int.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: James Bottomley <James.Bottomley@hansenpartnership.com>
2009-02-17 13:01:51 -08:00
James Bottomley bf33a70a73 x86: fix "__udivdi3" [drivers/scsi/aha1542.ko] undefined
Commit 976e8f677e ("x86: asm/io.h: unify
virt_to_phys/phys_to_virt") changed the return of virt_to_phys from long
to phys_addr_t which is unsigned long long on a PAE platform.

So, I could suggest a fix below since isa addresses may never be above
32 bits.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-13 21:02:02 +01:00
Ingo Molnar a56cdcb662 Merge branches 'x86/acpi', 'x86/asm', 'x86/cpudetect', 'x86/crashdump', 'x86/debug', 'x86/defconfig', 'x86/doc', 'x86/header-fixes', 'x86/headers' and 'x86/minor-fixes' into x86/core 2009-02-13 09:46:36 +01:00
Ingo Molnar 881c47760b Merge branch 'x86/cleanups' into x86/core 2009-02-13 09:45:42 +01:00
Ingo Molnar 891393745a Merge commit 'v2.6.29-rc4' into x86/cleanups 2009-02-11 11:38:55 +01:00
Jeremy Fitzhardinge 133822c5c0 x86: asm/io.h: unify ioremap prototypes
Impact: unify identical code

asm/io_32.h and _64.h have identical prototypes for the ioremap family
of functions.  The 32-bit header had a more descriptive comment.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-02-06 13:29:52 -08:00
Jeremy Fitzhardinge 976e8f677e x86: asm/io.h: unify virt_to_phys/phys_to_virt
Impact: unify identical code

asm/io_32.h and _64.h has functionally identical definitions for
virt_to_phys, phys_to_virt, page_to_phys, and the isa_* variants, so
just unify them.

The only slightly functional change is using phys_addr_t for the
physical address argument and return val.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
2009-02-06 13:29:44 -08:00
Jeremy Fitzhardinge a448720ca3 x86: unify asm/io.h: IO_SPACE_LIMIT
Impact: Cleanup (trivial unification)

Move common define IO_SPACE_LIMIT from <asm/io_*.h> to <asm/io.h>.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-01-28 22:34:17 -08:00
Ingo Molnar 74b6eb6b93 Merge branches 'x86/asm', 'x86/cleanups', 'x86/cpudetect', 'x86/debug', 'x86/doc', 'x86/header-fixes', 'x86/mm', 'x86/paravirt', 'x86/pat', 'x86/setup-v2', 'x86/subarch', 'x86/uaccess' and 'x86/urgent' into x86/core 2009-01-28 23:13:53 +01:00
venkatesh.pallipadi@intel.com d639bab8da x86 PAT: ioremap_wc should take resource_size_t parameter
Impact: fix/extend ioremap_wc() beyond 4GB aperture on 32-bit

ioremap_wc() was taking in unsigned long parameter, where as it should take
64-bit resource_size_t parameter like other ioremap variants.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-22 11:53:42 +01:00
Jan Beulich a3c6018e56 x86: fix assumed to be contiguous leaf page tables for kmap_atomic region (take 2)
Debugging and original patch from Nick Piggin <npiggin@suse.de>

The early fixmap pmd entry inserted at the very top of the KVA is causing the
subsequent fixmap mapping code to not provide physically linear pte pages over
the kmap atomic portion of the fixmap (which relies on said property to
calculate pte addresses).

This has caused weird boot failures in kmap_atomic much later in the boot
process (initial userspace faults) on a 32-bit PAE system with a larger number
of CPUs (smaller CPU counts tend not to run over into the next page so don't
show up the problem).

Solve this by attempting to clear out the page table, and copy any of its
entries to the new one. Also, add a bug if a nonlinear condition is encountered
and can't be resolved, which might save some hours of debugging if this fragile
scheme ever breaks again...

Once we have such logic, we can also use it to eliminate the early ioremap
trickery around the page table setup for the fixmap area. This also fixes
potential issues with FIX_* entries sharing the leaf page table with the early
ioremap ones getting discarded by early_ioremap_clear() and not restored by
early_ioremap_reset(). It at once eliminates the temporary (and configuration,
namely NR_CPUS, dependent) unavailability of early fixed mappings during the
time the fixmap area page tables get constructed.

Finally, also replace the hard coded calculation of the initial table space
needed for the fixmap area with a proper one, allowing kernels configured for
large CPU counts to actually boot.

Based-on: Nick Piggin <npiggin@suse.de>
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-01-16 13:47:04 +01:00
FUJITA Tomonori 181de82ee3 x86: remove dead BIO_VMERGE_BOUNDARY definition
Impact: cleanup, remove dead code

The block layer dropped the virtual merge feature
(b8b3e16cfe).

BIO_VMERGE_BOUNDARY definition is meaningless now.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-12-03 08:26:40 +01:00
Ingo Molnar 93093d099e x86: provide readq()/writeq() on 32-bit too, complete
if HAVE_READQ/HAVE_WRITEQ are defined, the full range of readq/writeq
APIs has to be provided to drivers:

 drivers/infiniband/hw/amso1100/c2.c: In function 'c2_tx_ring_alloc':
 drivers/infiniband/hw/amso1100/c2.c:133: error: implicit declaration of function '__raw_writeq'

So provide them on 32-bit as well. Also, map all the APIs to the
strongest ordering variant. It's way too easy to mess such details
up in drivers and the difference between "memory" and "" constrained
asm() constructs is in the noise range.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-30 10:26:18 +01:00
Ingo Molnar a0b1131e47 x86: provide readq()/writeq() on 32-bit too, cleanup
Impact: cleanup

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-30 09:38:19 +01:00
Hitoshi Mitake 2c5643b1c5 x86: provide readq()/writeq() on 32-bit too
Impact: add new API for drivers

Add implementation of readq/writeq to x86_32, and add config value to
the x86 architecture to determine existence of readq/writeq.

Signed-off-by: Hitoshi Mitake <h.mitake@gmail.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-30 09:38:16 +01:00
Harvey Harrison 1d6cf1feb8 x86: start annotating early ioremap pointers with __iomem
Impact: some new sparse warnings in e820.c etc, but no functional change.

As with regular ioremap, iounmap etc, annotate with __iomem.

Fixes the following sparse warnings, will produce some new ones
elsewhere in arch/x86 that will get worked out over time.

arch/x86/mm/ioremap.c:402:9: warning: cast removes address space of expression
arch/x86/mm/ioremap.c:406:10: warning: cast adds address space to expression (<asn:2>)
arch/x86/mm/ioremap.c:782:19: warning: Using plain integer as NULL pointer

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-29 08:05:14 +01:00
H. Peter Anvin 1965aae3c9 x86: Fix ASM_X86__ header guards
Change header guards named "ASM_X86__*" to "_ASM_X86_*" since:

a. the double underscore is ugly and pointless.
b. no leading underscore violates namespace constraints.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:23 -07:00