ARC700 MMU provides for tagging TLB entries with a 8-bit ASID to avoid
having to flush the TLB every task switch.

It also allows for a quick way to invalidate all the TLB entries for
task useful for:
* COW sementics during fork()
* task exit()ing
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

* ARC700 has VIPT L1 Caches
* Caches don't snoop and are not coherent
* Given the PAGE_SIZE and Cache associativity, we don't support aliasing
  D$ configurations (yet), but do allow aliasing I$ configs
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Per Al Viro's "signals for dummies" https://lkml.org/lkml/2012/12/6/366
there are 3 golden rules for (not) restarting syscalls:

"	What we need to guarantee is
* restarts do not happen on signals caught in interrupts or exceptions
* restarts do not happen on signals caught in sigreturn()
* restart should happen only once, even if we get through do_signal()
  many times."

ARC Port already handled #1, this patch fixes #2 and #3.

We use the additional state in pt_regs->orig_r8 to ckh if restarting
has already been done once.

Thanks to Al Viro for spotting this.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>

To avoid multiple syscall restarts (multiple signals) or no restart at
all (sigreturn), we need just an extra bit of state "literally 1 bit" in
struct pt_regs. orig_r8 is the best place to do this, however given the
way it is encoded currently, we can't add anything simplistically.

Current orig_r8:
* syscalls   -> 1 to NR_SYSCALLS
* Exceptions -> NR_SYSCALLS + 1
* Break-point-> NR_SYSCALLS + 2

In new scheme it is a bit-field
* lower short word contains the  exact event type (and a new bit to represent
   restart semantics : if syscall was already / can't be restarted)
* upper short word optionally containing the syscall num - needed by
  likes of tracehooks etc

This patch only changes how orig_r8 is organised and nothing should
change behaviourily.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>

Includes following fixes courtesy review by Al-Viro

* Tracer poke to Callee-regs were lost

  Before going off into do_signal( ) we save the user-mode callee regs
  (as they are not saved by default as part of pt_regs). This is to make
  sure that that a Tracer (if tracing related signal) is able to do likes
  of PEEKUSR(callee-reg).

  However in return path we were simply discarding the user-mode callee
  regs, which would break a POKEUSR(callee-reg) from a tracer.

* Issue related to multiple syscall restarts are addressed in next patch
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: NJonas Bonn <jonas@southpole.se>

ARC700 includes 2 in-core 32bit timers TIMER0 and TIMER1.
Both have exactly same capabilies.

* programmable to count from TIMER<n>_CNT to TIMER<n>_LIMIT
* for count 0 and LIMIT ~1, provides a free-running counter by
    auto-wrapping when limit is reached.
* optionally interrupt when LIMIT is reached (oneshot event semantics)
* rearming the interrupt provides periodic semantics
* run at CPU clk

ARC Linux uses TIMER0 for clockevent (periodic/oneshot) and TIMER1 for
clocksource (free-running clock).

Newer cores provide RTSC insn which gives a 64bit cpu clk snapshot hence
is more apt for clocksource when available.

SMP poses a bit of challenge for global timekeeping clocksource /
sched_clock() backend:
 -TIMER1 based local clocks are out-of-sync hence can't be used
  (thus we default to jiffies based cs as well as sched_clock() one/both
  of which platform can override with it's specific hardware assist)
 -RTSC is only allowed in SMP if it's cross-core-sync (Kconfig glue
  ensures that) and thus usable for both requirements.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>

This includes support for generic clone/for/vfork/execve
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This contains:
-bootup arch IRQ init: init_IRQ(), arc_init_IRQ()
-generic IRQ subsystem glue: arch_do_IRQ()
-basic IRQ chip setup for in-core intc
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>

Hand optimised asm code for ARC700 pipeline.
Originally written/optimized by Joern Rennecke
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Joern Rennecke <joern.rennecke@embecosm.com>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

* L1_CACHE_SHIFT
* PAGE_SIZE, PAGE_OFFSET
* struct pt_regs, struct user_regs_struct
* struct thread_struct, cpu_relax(), task_pt_regs(), start_thread(), ...
* struct thread_info, THREAD_SIZE, INIT_THREAD_INFO(), TIF_*, ...
* BUG()
* ELF_*
* Elf_*

To disallow user-space visibility into some of the core kernel data-types
such as struct pt_regs, #ifdef __KERNEL__ which also makes the UAPI header
spit (further patch in the series) to NOT export it to asm/uapi/ptrace.h
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Jonas Bonn <jonas.bonn@gmail.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Acked-by: NArnd Bergmann <arnd@arndb.de>

TBD: do_csum still needs to be written in asm
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

arches can have more efficient implementation of these routines
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Override asm-generic implementations. We basically gain on 2 fronts

* checks for alignment no longer needed as we are only doing "unit"
  sized copies.

  (Careful observer could argue that While the kernel buffers are aligned,
   the user buffer in theory might not be - however in that case the
   user space is already broken when it tries to deref a hword/word
   straddling word boundary - so we are not making it any worse).

* __copy_{to,from}_user( ) returns bytes that couldn't be copied,
  whereas get_user() returns 0 for success or -EFAULT (not size). Thus
  the code to do leftover bytes calculation can be avoided as well.

The savings were significant: ~17k of code.

bloat-o-meter vmlinux_uaccess_pre vmlinux_uaccess_post
add/remove: 0/4 grow/shrink: 8/118 up/down: 1262/-18758 (-17496)
							^^^^^^^^^
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

As of now these default to calling the arch provided __copy_{to,from}_user()
routines which being general purpose (w.r.t buffer alignment and lengths)
would lead to alignment checks in generated code (for arches which don't
support unaligned load/stores).

Given that in this case we already know that data involved is "unit"
sized and aligned, using the vanilla copy backend is a bit wasteful.

This change thus allows arches to over-ride the aforementioned routines.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This is because mm_segment_t is exported by arch code, while seqment_eq
assumes it will have .seg element.
Acked-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

This covers the UP / SMP (with no hardware assist for atomic r-m-w) as
well as ARC700 LLOCK/SCOND insns based.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

ARC700 has an in-core intc which provides 2 priorities (a.k.a.) "levels"
of interrupts (per IRQ) hencforth referred to as L1/L2 interrupts.

CPU flags register STATUS32 has Interrupt Enable bits per level (E1/E2)
to globally enable (or disable) all IRQs at a level. Hence the
implementation of arch_local_irq_{save,restore,enable,disable}( )

The STATUS32 reg can be r/w only using the AUX Interface of ARC, hence
the use of LR/SR instructions. Further, E1/E2 bits in there can only be
updated using the FLAG insn.

The intc supports 32 interrupts - and per IRQ enabling is controlled by
a bit in the AUX_IENABLE register, hence the implmentation of
arch_{,un}mask_irq( ) routines.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>

Arnd in his review pointed out that arch Kconfig organisation has several
deficiencies:

* Build time entries for things which can be runtime extracted from DT
  (e.g. SDRAM size, core clk frequency..)
* Not multi-platform-image-build friendly (choice .. endchoice constructs)
* cpu variants support (750/770) is exclusive.

The first 2 have been fixed in subsequent patches.
Due to the nature of the 750 and 770, it is not possible to build for
both together, w/o special runtime glue code which would hurt
performance.
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: NSam Ravnborg <sam@ravnborg.org>

Signed-off-by: NVineet Gupta <vgupta@synopsys.com>

Pull btrfs fixes from Chris Mason:
 "It turns out that we had two crc bugs when running fsx-linux in a
  loop.  Many thanks to Josef, Miao Xie, and Dave Sterba for nailing it
  all down.  Miao also has a new OOM fix in this v2 pull as well.

  Ilya fixed a regression Liu Bo found in the balance ioctls for pausing
  and resuming a running balance across drives.

  Josef's orphan truncate patch fixes an obscure corruption we'd see
  during xfstests.

  Arne's patches address problems with subvolume quotas.  If the user
  destroys quota groups incorrectly the FS will refuse to mount.

  The rest are smaller fixes and plugs for memory leaks."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (30 commits)
  Btrfs: fix repeated delalloc work allocation
  Btrfs: fix wrong max device number for single profile
  Btrfs: fix missed transaction->aborted check
  Btrfs: Add ACCESS_ONCE() to transaction->abort accesses
  Btrfs: put csums on the right ordered extent
  Btrfs: use right range to find checksum for compressed extents
  Btrfs: fix panic when recovering tree log
  Btrfs: do not allow logged extents to be merged or removed
  Btrfs: fix a regression in balance usage filter
  Btrfs: prevent qgroup destroy when there are still relations
  Btrfs: ignore orphan qgroup relations
  Btrfs: reorder locks and sanity checks in btrfs_ioctl_defrag
  Btrfs: fix unlock order in btrfs_ioctl_rm_dev
  Btrfs: fix unlock order in btrfs_ioctl_resize
  Btrfs: fix "mutually exclusive op is running" error code
  Btrfs: bring back balance pause/resume logic
  btrfs: update timestamps on truncate()
  btrfs: fix btrfs_cont_expand() freeing IS_ERR em
  Btrfs: fix a bug when llseek for delalloc bytes behind prealloc extents
  Btrfs: fix off-by-one in lseek
  ...

Pull cifs fixes from Steve French:
 "Two small cifs fixes"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  fs/cifs/cifs_dfs_ref.c: fix potential memory leakage
  cifs: fix srcip_matches() for ipv6

Pull kvm fixlet from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: PPC: Emulate dcbf

Pull ARM fixes from Russell King:
 "A number of fixes:

  Patrik found a problem with preempt counting in the VFP assembly
  functions which can cause the preempt count to be upset.

  Nicolas fixed a problem with the parsing of the DT when it straddles a
  1MB boundary.

  Subhash Jadavani reported a problem with sparsemem and our highmem
  support for cache maintanence for DMA areas, and TI found a bug in
  their strongly ordered memory mapping type.

  Also, three fixes by way of Will Deacon's tree from Dave Martin for
  instruction compatibility and Marc Zyngier to fix hypervisor boot mode
  issues."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7629/1: mm: Fix missing XN flag for for MT_MEMORY_SO
  ARM: DMA: Fix struct page iterator in dma_cache_maint() to work with sparsemem
  ARM: 7628/1: head.S: map one extra section for the ATAG/DTB area
  ARM: 7627/1: Predicate preempt logic on PREEMP_COUNT not PREEMPT alone
  ARM: virt: simplify __hyp_stub_install epilog
  ARM: virt: boot secondary CPUs through the right entry point
  ARM: virt: Avoid bx instruction for compatibility with <=ARMv4

Pull ARM SoC fixes from Olof Johansson:
 "Here's a long-pending fixes pull request for arm-soc (I didn't send
  one in the -rc4 cycle).

  The larger deltas are from:

   - A fixup of error paths in the mvsdio driver

   - Header file move for a driver that hadn't been properly converted
     to multiplatform on i.MX, which was causing build failures when
     included

   - Device tree updates for at91 dealing mostly with their new pinctrl
     setup merged in 3.8 and mistakes in those initial configs

  The rest are the normal mix of small fixes all over the place; sunxi,
  omap, imx, mvebu, etc, etc."

* tag 'fixes-for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (40 commits)
  mfd: vexpress-sysreg: Don't skip initialization on probe
  ARM: vexpress: Enable A7 cores in V2P-CA15_A7's Device Tree
  ARM: vexpress: extend the MPIDR range used for pen release check
  ARM: at91/dts: correct comment in at91sam9x5.dtsi for mii
  ARM: at91/at91_dt_defconfig: add at91sam9n12 SoC to DT defconfig
  ARM: at91/at91_dt_defconfig: remove memory specification to cmdline
  ARM: at91/dts: add macb mii pinctrl config for kizbox
  ARM: at91: rm9200: remake the BGA as default version
  ARM: at91: fix gpios on i2c-gpio for RM9200 DT
  ARM: at91/at91sam9x5 DTS: add SCK USART pins
  ARM: at91/at91sam9x5 DTS: correct wrong PIO BANK values on u(s)arts
  ARM: at91/at91-pinctrl documentation: fix typo and add some details
  ARM: kirkwood: fix missing #interrupt-cells property
  mmc: mvsdio: use devm_ API to simplify/correct error paths.
  clk: mvebu/clk-cpu.c: fix memory leakage
  ARM: OMAP2+: omap4-panda: add UART2 muxing for WiLink shared transport
  ARM: OMAP2+: DT node Timer iteration fix
  ARM: OMAP2+: Fix section warning for omap_init_ocp2scp()
  ARM: OMAP2+: fix build break for omapdrm
  ARM: OMAP2: Fix missing omap2xxx_clkt_vps_late_init function calls
  ...

Pull ACPI and power management fixes from Rafael Wysocki:

 - Two cpuidle initialization fixes from Konrad Rzeszutek Wilk.

 - cpufreq regression fixes for AMD processors from Borislav Petkov,
   Stefan Bader, and Matthew Garrett.

 - ACPI cpufreq fix from Thomas Schlichter.

 - cpufreq and devfreq fixes related to incorrect usage of operating
   performance points (OPP) framework and RCU from Nishanth Menon.

 - APEI workaround for incorrect BIOS information from Lans Zhang.

* tag 'pm+acpi-for-3.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: Add module aliases for acpi-cpufreq
  ACPI: Check MSR valid bit before using P-state frequencies
  PM / devfreq: exynos4_bus: honor RCU lock usage
  PM / devfreq: add locking documentation for recommended_opp
  cpufreq: cpufreq-cpu0: use RCU locks around usage of OPP
  cpufreq: OMAP: use RCU locks around usage of OPP
  ACPI, APEI: Fixup incorrect 64-bit access width firmware bug
  ACPI / processor: Get power info before updating the C-states
  powernow-k8: Add a kconfig dependency on acpi-cpufreq
  ACPI / cpuidle: Fix NULL pointer issues when cpuidle is disabled
  intel_idle: Don't register CPU notifier if we are not running.

Pull regmap fixes from Mark Brown:
 "One more oversight in the debugfs code was reported and fixed, plus a
  documentation fix."

* tag 'regmap-fix-3.8-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: fix small typo in regmap_bulk_write comment
  regmap: debugfs: Fix seeking from the cache

Pull slave-dmaengine fixes from Vinod Koul:
 "A few fixes on slave dmanengine.  There are trivial fixes in imx-dma,
  tegra-dma & ioat driver"

* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
  dma: tegra: implement flags parameters for cyclic transfer
  dmaengine: imx-dma: Disable use of hw_chain to fix sg_dma transfers.
  ioat: Fix DMA memory sync direction correct flag

Pill i2c fixes from Wolfram Sang:
 "Here are a few, typical driver fixes for the I2C subsystem"

* 'i2c-embedded/for-current' of git://git.pengutronix.de/git/wsa/linux:
  i2c-designware: add missing MODULE_LICENSE
  i2c: omap: fix draining irq handling
  i2c: omap: errata i462: fix incorrect ack for arbitration lost interrupt
  i2c: muxes: fix wrong use of sizeof(ptr)
  i2c: sirf: register i2c_client from dt child-nodes in probe entry
  i2c: mxs: Fix type of error code
  i2c: mxs: Fix misuse init_completion

btrfs_start_delalloc_inodes() locks the delalloc_inodes list, fetches the
first inode, unlocks the list, triggers btrfs_alloc_delalloc_work/
btrfs_queue_worker for this inode, and then it locks the list, checks the
head of the list again. But because we don't delete the first inode that it
deals with before, it will fetch the same inode. As a result, this function
allocates a huge amount of btrfs_delalloc_work structures, and OOM happens.

Fix this problem by splice this delalloc list.
Reported-by: NAlex Lyakas <alex.btrfs@zadarastorage.com>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

The max device number of single profile is 1, not 0 (0 means 'as many as
possible'). Fix it.

Cc: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

First, though the current transaction->aborted check can stop the commit early
and avoid unnecessary operations, it is too early, and some transaction handles
don't end, those handles may set transaction->aborted after the check.

Second, when we commit the transaction, we will wake up some worker threads to
flush the space cache and inode cache. Those threads also allocate some transaction
handles and may set transaction->aborted if some serious error happens.

So we need more check for ->aborted when committing the transaction. Fix it.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

We may access and update transaction->aborted on the different CPUs without
lock, so we need ACCESS_ONCE() wrapper to prevent the compiler from creating
unsolicited accesses and make sure we can get the right value.
Signed-off-by: NMiao Xie <miaox@cn.fujitsu.com>
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>

I noticed a WARN_ON going off when adding csums because we were going over
the amount of csum bytes that should have been allowed for an ordered
extent.  This is a leftover from when we used to hold the csums privately
for direct io, but now we use the normal ordered sum stuff so we need to
make sure and check if we've moved on to another extent so that the csums
are added to the right extent.  Without this we could end up with csums for
bytenrs that don't have extents to cover them yet.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>