If Xenstore sends back a XS_ERROR for TRANSACTION_END, the driver BUGs
because it cannot find the matching transaction in the list.  For
TRANSACTION_START, it leaks memory.

Check the message as returned from xenbus_dev_request_and_reply(), and
clean up for TRANSACTION_START or discard the error for
TRANSACTION_END.
Signed-off-by: Jennifer Herbert <Jennifer.Herbert@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

For a PV guest, use the find_special_page op to find the right page.
To handle VMAs being split, remember the start of the original VMA so
the correct index in the pages array can be calculated.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

In an x86 PV guest, get_user_pages_fast() on a userspace address range
containing foreign mappings does not work correctly because the M2P
lookup of the MFN from a userspace PTE may return the wrong page.

Force get_user_pages_fast() to fail on such addresses by marking the PTEs
as special.

If Xen has XENFEAT_gnttab_map_avail_bits (available since at least
4.0), we can do so efficiently in the grant map hypercall.  Otherwise,
it needs to be done afterwards.  This is both inefficient and racy
(the mapping is visible to the task before we fixup the PTEs), but
will be fine for well-behaved applications that do not use the mapping
until after the mmap() system call returns.

Guests with XENFEAT_auto_translated_physmap (ARM and x86 HVM or PVH)
do not need this since get_user_pages() has always worked correctly
for them.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Use gnttab_unmap_refs_async() to wait until the mapped pages are no
longer in use before unmapping them.

This allows blkback to use network storage which may retain refs to
pages in queued skbs after the block I/O has completed.
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Jens Axboe <axboe@kernel.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Use gnttab_unmap_refs_async() to wait until the mapped pages are no
longer in use before unmapping them.

This allows userspace programs to safely use Direct I/O and AIO to a
network filesystem which may retain refs to pages in queued skbs after
the filesystem I/O has completed.
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Unmapping may require sleeping and we unmap while holding priv->lock, so
convert it to a mutex.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Introduce gnttab_unmap_refs_async() that can be used to safely unmap
pages that may be in use (ref count > 1).  If the pages are in use the
unmap is deferred and retried later.  This polling is not very clever
but it should be good enough if the cases where the delay is necessary
are rare.

The initial delay is 5 ms and is increased linearly on each subsequent
retry (to reduce load if the page is in use for a long time).

This is needed to allow block backends using grant mapping to safely
use network storage (block or filesystem based such as iSCSI or NFS).

The network storage driver may complete a block request whilst there
is a queued network packet retry (because the ack from the remote end
races with deciding to queue the retry).  The pages for the retried
packet would be grant unmapped and the network driver (or hardware)
would access the unmapped page.
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Use the foreign page flag in netback to get the domid and grant ref
needed for the grant copy.  This signficiantly simplifies the netback
code and makes netback work with foreign pages from other backends
(e.g., blkback).

This allows blkback to use iSCSI disks provided by domUs running on
the same host.
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Use the "foreign" page flag to mark pages that have a grant map.  Use
page->private to store information of the grant (the granting domain
and the grant reference).
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Add gnttab_alloc_pages() and gnttab_free_pages() to allocate/free pages
suitable to for granted maps.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Ballooned pages are always used for grant maps which means the
original frame does not need to be saved in page->index nor restored
after the grant unmap.

This allows the workaround in netback for the conflicting use of the
(unionized) page->index and page->pfmemalloc to be removed.
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

The scratch frame mappings for ballooned pages and the m2p override
are broken.  Remove them in preparation for replacing them with
simpler mechanisms that works.

The scratch pages did not ensure that the page was not in use.  In
particular, the foreign page could still be in use by hardware.  If
the guest reused the frame the hardware could read or write that
frame.

The m2p override did not handle the same frame being granted by two
different grant references.  Trying an M2P override lookup in this
case is impossible.

With the m2p override removed, the grant map/unmap for the kernel
mappings (for x86 PV) can be easily batched in
set_foreign_p2m_mapping() and clear_foreign_p2m_mapping().
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

When unmapping grants, instead of converting the kernel map ops to
unmap ops on the fly, pre-populate the set of unmap ops.

This allows the grant unmap for the kernel mappings to be trivially
batched in the future.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

The foreign page flag will be used by Xen guests to mark pages that
have grant mappings of frames from other (foreign) guests.

The foreign flag is an alias for the existing (Xen-specific) pinned
flag.  This is safe because pinned is only used on pages used for page
tables and these cannot also be foreign.
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

The optional find_special_page VMA operation is used to lookup the
pages backing a VMA.  This is useful in cases where the normal
mechanisms for finding the page don't work.  This is only called if
the PTE is special.

One use case is a Xen PV guest mapping foreign pages into userspace.

In a Xen PV guest, the PTEs contain MFNs so get_user_pages() (for
example) must do an MFN to PFN (M2P) lookup before it can get the
page.  For foreign pages (those owned by another guest) the M2P lookup
returns the PFN as seen by the foreign guest (which would be
completely the wrong page for the local guest).

This cannot be fixed up improving the M2P lookup since one MFN may be
mapped onto two or more pages so getting the right page is impossible
given just the MFN.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>

Remove a nested ifdef.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

The file arch/x86/xen/mmu.c has some functions that can be annotated
with "__init".
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Some more functions in arch/x86/xen/setup.c can be made "__init".
xen_ignore_unusable() can be made "static".
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

In many places in arch/x86/xen/setup.c wrong types are used for
physical addresses (u64 or unsigned long long). Use phys_addr_t
instead.

Use macros already defined instead of open coding them.

Correct some other type mismatches.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Remove extern declarations in arch/x86/xen/setup.c which are either
not used or redundant. Move needed other extern declarations to
xen-ops.h
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

Call __set_current_state() instead of assigning the new state directly.
These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments,
keeping track of who changed the state.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

As a module_init() function, this should have been this way from the
beginning.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

In Dom0's the use of the TSC clocksource (whenever it is stable enough to
be used) instead of the Xen clocksource should not cause any issues, as
Dom0 VMs never live-migrated.  The TSC clocksource is somewhat more
efficient than the Xen paravirtualised clocksource, thus it should have
higher rating.

This patch decreases the rating of the Xen clocksource in Dom0s to 275.
Which is half-way between the rating of the TSC clocksource (300) and the
hpet clocksource (250).

Cc: Anthony Liguori <aliguori@amazon.com>
Signed-off-by: Imre Palik <imrep@amazon.de>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

With Xen configured into the arm64 kernel, any driver allocating
DMA'able memory for PCI operations, must be GPL compatible, regardless
of its interaction with Xen. This patch relaxes the GPL requirement of
xen_dma_ops and its dependencies to allow open source drivers to be
compiled for the arm64 architecture.
Signed-off-by: Chuck Tuffli <chuck.tuffli@emulex.com>

Pull ARM SoC fixes from Olof Johansson:
 "We've been sitting on our fixes branch for a while, so this batch is
  unfortunately on the large side.

  A lot of these are tweaks and fixes to device trees, fixing various
  bugs around clocks, reg ranges, etc.  There's also a few defconfig
  updates (which are on the late side, no more of those).

  All in all the diffstat is bigger than ideal at this time, but nothing
  in here seems particularly risky"

* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (31 commits)
  reset: sunxi: fix spinlock initialization
  ARM: dts: disable CCI on exynos5420 based arndale-octa
  drivers: bus: check cci device tree node status
  ARM: rockchip: disable jtag/sdmmc autoswitching on rk3288
  ARM: nomadik: fix up leftover device tree pins
  ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree
  ARM: at91/dt: sam9263: Add missing clocks to lcdc node
  ARM: at91: sama5d3: dt: correct the sound route
  ARM: at91/dt: sama5d4: fix the timer reg length
  ARM: exynos_defconfig: Enable LM90 driver
  ARM: exynos_defconfig: Enable options for display panel support
  arm: dts: Use pmu_system_controller phandle for dp phy
  ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances
  ARM: dts: berlin: correct BG2Q's SM GPIO location.
  ARM: dts: berlin: add broken-cd and set bus width for eMMC in Marvell DMP DT
  ARM: dts: berlin: fix io clk and add missing core clk for BG2Q sdhci2 host
  ARM: dts: Revert disabling of smc91x for n900
  ARM: dts: imx51-babbage: Fix ULPI PHY reset modelling
  ARM: dts: dra7-evm: fix qspi device tree partition size
  ARM: omap2plus_defconfig: use CONFIG_CPUFREQ_DT
  ...

Pull clock driver fixes from Mike Turquette:
 "Small number of fixes for clock drivers and a single null pointer
  dereference fix in the framework core code.

  The driver fixes vary from fixing section mismatch warnings to
  preventing machines from hanging (and preventing developers from
  crying)"

* tag 'clk-fixes-for-linus' of git://git.linaro.org/people/mike.turquette/linux:
  clk: fix possible null pointer dereference
  Revert "clk: ppc-corenet: Fix Section mismatch warning"
  clk: rockchip: fix deadlock possibility in cpuclk
  clk: berlin: bg2q: remove non-exist "smemc" gate clock
  clk: at91: keep slow clk enabled to prevent system hang
  clk: rockchip: fix rk3288 cpuclk core dividers
  clk: rockchip: fix rk3066 pll lock bit location
  clk: rockchip: Fix clock gate for rk3188 hclk_emem_peri
  clk: rockchip: add CLK_IGNORE_UNUSED flag to fix rk3066/rk3188 USB Host

Pull SCSI fixes from James Bottomley:
 "This is one fix for a Multiqueue sleeping in invalid context problem
  and a MAINTAINER file update for Qlogic"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: ->queue_rq can't sleep
  MAINTAINERS: Update maintainer list for qla4xxx

The commit 646cafc6 (clk: Change clk_ops->determine_rate to
return a clk_hw as the best parent) opens a possibility for
null pointer dereference, fix this.
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

This reverts commit da788acb.

That commit tried to fix the section mismatch warning by moving the
ppc_corenet_clk_driver struct to init section. This is definitely wrong
because the kernel would free the memories occupied by this struct
after boot while this driver is still registered in the driver core.
The kernel would panic when accessing this driver struct.

Cc: stable@vger.kernel.org # 3.17
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Michael Turquette <mturquette@linaro.org>

Lockdep reported a possible deadlock between the cpuclk lock and for example
the i2c driver.

       CPU0                    CPU1
       ----                    ----
  lock(clk_lock);
                               local_irq_disable();
                               lock(&(&i2c->lock)->rlock);
                               lock(clk_lock);
  <Interrupt>
    lock(&(&i2c->lock)->rlock);

 *** DEADLOCK ***

The generic clock-types of the core ccf already use spin_lock_irqsave when
touching clock registers, so do the same for the cpuclk.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
[mturquette@linaro.org: removed initialization of "flags"]

Pull dmaengine fixes from Vinod Koul:
 "Two patches, the first by Andy to fix dw dmac runtime pm and second
  one by me to fix the dmaengine headers in MAINTAINERS"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dmaengine: dw: balance PM runtime calls
  MAINTAINERS: dmaengine: fix the header file for dmaengine

Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also two PMU driver fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf tools powerpc: Use dwfl_report_elf() instead of offline.
  perf tools: Fix segfault for symbol annotation on TUI
  perf test: Fix dwarf unwind using libunwind.
  perf tools: Avoid build splat for syscall numbers with uclibc
  perf tools: Elide strlcpy warning with uclibc
  perf tools: Fix statfs.f_type data type mismatch build error with uclibc
  tools: Remove bitops/hweight usage of bits in tools/perf
  perf machine: Fix __machine__findnew_thread() error path
  perf tools: Fix building error in x86_64 when dwarf unwind is on
  perf probe: Propagate error code when write(2) failed
  perf/x86/intel: Fix bug for "cycles:p" and "cycles:pp" on SLM
  perf/rapl: Fix sysfs_show() initialization for RAPL PMU

Merge tag 'perf-urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

Pull perf/urgent fixes from Arnaldo Carvalho de Melo:

  - Fix segfault when using both the map symtab viewer and annotation
    in the TUI (Namhyung Kim).

  - uClibc build fixes (Alexey Brodkin, Vineet Gupta).

  - bitops/hweight were moved from tools/perf/ too tools/include, move
    some leftovers (Arnaldo Carvalho de Melo)

  - Fix dwarf unwind x86_64 build error (Namhyung Kim)

  - Fix __machine__findnew_thread() error path (Namhyung Kim)

  - Propagate error code when write(2) failed in 'perf probe' (Namhyung Kim)

  - Use dwfl_report_elf() instead of offline in powerpc bits to
    properly handle non prelinked DSOs (Sukadev Bhattiprolu).

  - Fix dwarf unwind using libunwind in 'perf test' (Wang Nan)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Merge tag 'samsung-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into fixes

Merge "Samsung fixes for v3.19" from Kukjin Kim:

Samsung fixes for v3.19
- exynos_defconfig: enable LM90 driver and display panel support
   - HWMON
   - SENSORS_LM90
   - Direct Rendering Manager (DRM)
   - DRM bridge registration and lookup framework
   - Parade ps8622/ps8625 eDP/LVDS bridge
   - NXP ptn3460 eDP/LVDS bridge
   - Exynos Fully Interactive Mobile Display controller (FIMD)
   - Panel registration and lookup framework
   - Simple panels
   - Backlight & LCD device support

- use pmu_system_controller phandle for dp phy
  : DP PHY requires pmu_system_controller to handle PMU reg. now

* tag 'samsung-fixes-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: exynos_defconfig: Enable LM90 driver
  ARM: exynos_defconfig: Enable options for display panel support
  arm: dts: Use pmu_system_controller phandle for dp phy
Signed-off-by: Olof Johansson <olof@lixom.net>

Call spin_lock_init() before the spinlocks are used, both in early init
and probe functions preventing a lockdep splat.

I have been observing lockdep complaining [1] during boot on my a80 optimus [2]
when CONFIG_PROVE_LOCKING has been enabled. This patch resolves the splat,
and has been tested on a few other sunxi platforms without issue.

[1] http://storage.kernelci.org/next/next-20150107/arm-multi_v7_defconfig+CONFIG_PROVE_LOCKING=y/lab-tbaker/boot-sun9i-a80-optimus.html
[2] http://kernelci.org/boot/?a80-optimusSigned-off-by: Tyler Baker <tyler.baker@linaro.org>
Cc: <stable@vger.kernel.org>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'renesas-soc-fixes-for-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into fixes

Merge "Renesas ARM Based SoC Fixes for v3.19" from Simon Horman:

Renesas ARM Based SoC Fixes for v3.19

This pull request is based on the last round of SoC updates for v3.19,
Fourth Round of Renesas ARM Based SoC Updates for v3.19, tagged as
renesas-soc3-for-v3.19, merged into your next/soc branch and included in
v3.19-rc1.

- ARM: shmobile: r8a7740: Instantiate GIC from C board code in legacy builds

  Set .control_parent for all irqpin instances for sh73a0 SoC when booting
  using legacy C.

- ARM: shmobile: r8a7740: Instantiate GIC from C board code in legacy builds

  This fixes a long standing problem which has been present since
  the sh73a0 SoC started using the INTC External IRQ pin driver.

  The patch that introduced the problem is 341eb546 ("ARM:
  shmobile: INTC External IRQ pin driver on sh73a0") which was included
  in v3.10.

* tag 'renesas-soc-fixes-for-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
  ARM: shmobile: sh73a0 legacy: Set .control_parent for all irqpin instances
  ARM: shmobile: r8a7740: Instantiate GIC from C board code in legacy builds

The arndale-octa board was giving "imprecise external aborts" during
boot-up with MCPM enabled. CCI enablement of the boot cluster was found
to be the cause of these aborts (possibly because the secure f/w was not
allowing it). Hence, disable CCI for the arndale-octa board.
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Tested-by: Tyler Baker <tyler.baker@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

The arm-cci driver completes the probe sequence even if the cci node is
marked as disabled. Add a check in the driver to honour the cci status
in the device tree.
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'at91-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91 into fixes

Merge "at91: fixes for 3.19 #1 (ter)" from Nicolas Ferre:

First fixes batch for AT91 on 3.19:
- fix some DT entries
- correct clock entry for the at91sam9263 LCD
- add a phy_fixup for Eth1 on sama5d4

* tag 'at91-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nferre/linux-at91:
  ARM: at91: board-dt-sama5: add phy_fixup to override NAND_Tree
  ARM: at91/dt: sam9263: Add missing clocks to lcdc node
  ARM: at91: sama5d3: dt: correct the sound route
  ARM: at91/dt: sama5d4: fix the timer reg length
Signed-off-by: Olof Johansson <olof@lixom.net>