This commit fixes the regression on Armada 370 (the kernal hang during
boot) introduced by the commit: "ARM: 7691/1: mm: kill unused
TLB_CAN_READ_FROM_L1_CACHE and use ALT_SMP instead".

When coming out of either a Wait for Interrupt (WFI) or a Wait for
Event (WFE) IDLE states, a specific timing sensitivity exists between
the retiring WFI/WFE instructions and the newly issued subsequent
instructions. This sensitivity can result in a CPU hang scenario.  The
workaround is to insert either a Data Synchronization Barrier (DSB) or
Data Memory Barrier (DMB) command immediately after the WFI/WFE
instruction.

This commit was based on the work of Lior Amsalem, but heavily
modified to apply the errata fix dynamically according to the
processor type thanks to the suggestions of Russell King and Nicolas
Pitre.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Willy Tarreau <w@1wt.eu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

The __cpu_logical_map array is statically initialized to 0, which is a valid
MPIDR value. To prevent issues with the current implementation, this patch
defines an MPIDR_INVALID value, and statically initializes the
__cpu_logical_map[] array to it. Entries in the arm_dt_init_cpu_maps()
tmp_map array used to stash DT reg properties while parsing DT are initialized
with the MPIDR_INVALID value as well for consistency.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull ARM fixes from Russell King:
 "The larger changes this time are

   - "ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page"
     which fixes more data corruption problems with O_DIRECT

   - "ARM: 7759/1: decouple CPU offlining from reboot/shutdown" which
     gets us back to working shutdown/reboot on SMP platforms

   - "ARM: 7752/1: errata: LoUIS bit field in CLIDR register is incorrect"
     which fixes a shutdown regression found in v3.10 on Versatile
     Express platforms.

  The remainder are the quite small, maybe one or two line changes"

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7759/1: decouple CPU offlining from reboot/shutdown
  ARM: 7756/1: zImage/virt: remove hyp-stub.S during distclean
  ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page
  ARM: 7754/1: Fix the CPU ID and the mask associated to the PJ4B
  ARM: 7753/1: map_init_section flushes incorrect pmd
  ARM: 7752/1: errata: LoUIS bit field in CLIDR register is incorrect

Commit f8b63c1 made flush_kernel_dcache_page a no-op assuming that
the pages it needs to handle are kernel mapped only.  However, for
example when doing direct I/O, pages with user space mappings may
occur.

Thus, continue to do lazy flushing if there are no user space
mappings.  Otherwise, flush the kernel cache lines directly.

Signed-off-by: Simon Baatz <gmbnomis@gmail.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: <stable@vger.kernel.org> # 3.2+
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull ARM fixes from Russell King:
 "The biggest two fixes are fixing a compilation error with the
  decompressor, and a problem with our __my_cpu_offset implementation.

  Other changes are very trivial and small, which seems to be the way
  for most -rc stuff."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7747/1: pcpu: ensure __my_cpu_offset cannot be re-ordered across barrier()
  ARM: 7750/1: update legacy CPU ID in decompressor cache support jump table
  ARM: 7743/1: compressed/head.S: work around new binutils warning
  ARM: 7742/1: topology: export cpu_topology
  ARM: 7737/1: fix kernel decompressor compilation error with CONFIG_DEBUG_SEMIHOSTING

Since the introduction of preemptible mmu_gather TLB fast mode has been
broken. TLB fast mode relies on there being absolutely no concurrency;
it frees pages first and invalidates TLBs later.

However now we can get concurrency and stuff goes *bang*.

This patch removes all tlb_fast_mode() code; it was found the better
option vs trying to patch the hole by entangling tlb invalidation with
the scheduler.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Reported-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

__my_cpu_offset is non-volatile, since we want its value to be cached
when we access several per-cpu variables in a row with preemption
disabled. This means that we rely on preempt_{en,dis}able to hazard
with the operation via the barrier() macro, so that we can't end up
migrating CPUs without reloading the per-cpu offset.

Unfortunately, GCC doesn't treat a "memory" clobber on a non-volatile
asm block as a side-effect, and will happily re-order it before other
memory clobbers (including those in prempt_disable()) and cache the
value. This has been observed to break the cmpxchg logic in the slub
allocator, leading to livelock in kmem_cache_alloc in mainline kernels.

This patch adds a dummy memory input operand to __my_cpu_offset,
forcing it to be ordered with respect to the barrier() macro.

Cc: <stable@vger.kernel.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull ARM fixes from Russell King:
 "A small number of fixes for stuff from the last merge window, and in
  one case (IRQ time accounting) the previous merge window."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: 7720/1: ARM v6/v7 cmpxchg64 shouldn't clear upper 32 bits of the old/new value
  ARM: 7715/1: MCPM: adapt to GIC changes after upstream merge
  ARM: 7714/1: mmc: mmci: Ensure return value of regulator_enable() is checked
  ARM: 7712/1: Remove trailing whitespace in arch/arm/Makefile
  ARM: 7711/1: dove: fix Dove cpu type from V7 to PJ4
  ARM: finally enable IRQ time accounting config

The implementation of cmpxchg64() for the ARM v6 and v7 architecture
casts parameter 2 and 3 (the old and new 64bit values) to an unsigned
long before calling the atomic_cmpxchg64() function. This clears
the top 32 bits of the old and new values, resulting in the wrong
values being compare-exchanged. Luckily, this only appears to be used
for 64-bit sched_clock, which we don't (yet) have on ARM.

This bug was introduced by commit 3e0f5a15f500 ("ARM: 7404/1: cmpxchg64:
use atomic64 and local64 routines for cmpxchg64").

Cc: <stable@vger.kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jaccon Bastiaansen <jaccon.bastiaansen@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Pull ARM Xen SMP updates from Stefano Stabellini:
 "This contains a bunch of Xen/ARM specific changes, including some
  fixes, SMP support for Xen on ARM, and moving the xenvm machine from
  mach-vexpress to mach-virt.

  The non-Xen files that are touched are arch/arm/Kconfig, to select
  ARM_PSCI on XEN, and arch/arm/boot/dts/Makefile, to build the xenvm
  DTB if CONFIG_ARCH_VIRT.

  Highlights:

   - Move xenvm to mach-virt.

   - Implement SMP support in Xen on ARM.

   - Add support for machine reboot and power off via Xen hypercalls"

* tag '3.9-rc3-smp-6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/sstabellini/xen:
  xen/arm: remove duplicated include from enlighten.c
  xen/arm: use sched_op hypercalls for machine reboot and power off
  xenvm: add a simple PSCI node and a second cpu
  xen/arm: XEN selects ARM_PSCI
  xen: move the xenvm machine to mach-virt
  xen/arm: SMP support
  xen/arm: implement HYPERVISOR_vcpu_op
  xen/arm: actually pass a non-NULL percpu pointer to request_percpu_irq