ARM: 7858/1: mm: make UACCESS_WITH_MEMCPY huge page aware

The memory pinning code in uaccess_with_memcpy.c does not check
for HugeTLB or THP pmds, and will enter an infinite loop should
a __copy_to_user or __clear_user occur against a huge page.

This patch adds detection code for huge pages to pin_page_for_write.
As this code can be executed in a fast path it refers to the actual
pmds rather than the vma. If a HugeTLB or THP is found (they have
the same pmd representation on ARM), the page table spinlock is
taken to prevent modification whilst the page is pinned.

On ARM, huge pages are only represented as pmds, thus no huge pud
checks are performed. (For huge puds one would lock the page table
in a similar manner as in the pmd case).

Two helper functions are introduced; pmd_thp_or_huge will check
whether or not a page is huge or transparent huge (which have the
same pmd layout on ARM), and pmd_hugewillfault will detect whether
or not a page fault will occur on write to the page.

Running the following test (with the chunking from read_zero
removed):
 $ dd if=/dev/zero of=/dev/null bs=10M count=1024
Gave:  2.3 GB/s backed by normal pages,
       2.9 GB/s backed by huge pages,
       5.1 GB/s backed by huge pages, with page mask=HPAGE_MASK.

After some discussion, it was decided not to adopt the HPAGE_MASK,
as this would have a significant detrimental effect on the overall
system latency due to page_table_lock being held for too long.
This could be revisited if split huge page locks are adopted.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Conflicts:
	arch/arm/include/asm/pgtable-2level.h
	arch/arm/include/asm/pgtable-3level.h
ARM: 7666/1: decompressor: add -mno-single-pic-base for building the decompressor

Before jumping to (position independent) C-code from the decompressor's
assembler world we set-up the C environment. This setup currently does not
set r9, which for arm-none-uclinux-uclibceabi toolchains is by default
expected to be the PIC offset base register (IE should point to the
beginning of the GOT).

Currently, therefore, in order to build working kernels that use the
decompressor it is necessary to use an arm-linux-gnueabi toolchain, or
similar. uClinux toolchains cause a prefetch abort to occur at the beginning
of the decompress_kernel function.

This patch allows uClinux toolchains to build bootable zImages by forcing
the -mno-single-pic-base option, which ensures that the location of the GOT
is re-derived each time it is required, and r9 becomes free for use as a
general purpose register.

This has a small (4% in instruction terms) advantage over the alternative of
setting r9 to point to the GOT before calling into the C-world.

Signed-off-by: Jonathan Austin <jonathan.austin@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: 8011/1: ARM hibernation / suspend-to-disk

Enable hibernation for ARM architectures and provide ARM
architecture specific calls used during hibernation.

The swsusp hibernation framework depends on the
platform first having functional suspend/resume.

Then, in order to enable hibernation on a given platform, a
platform_hibernation_ops structure may need to be registered with
the system in order to save/restore any SoC-specific / cpu specific
state needing (re)init over a suspend-to-disk/resume-from-disk cycle.

For example:

     - "secure" SoCs that have different sets of control registers
       and/or different CR reg access patterns.

     - SoCs with L2 caches as the activation sequence there is
       SoC-dependent; a full off-on cycle for L2 is not done
       by the hibernation support code.

     - SoCs requiring steps on wakeup _before_ the "generic" parts
       done by cpu_suspend / cpu_resume can work correctly.

     - SoCs having persistent state which is maintained during suspend
       and resume, but will be lost during the power off cycle after
       suspend-to-disk.

This is a rebase/rework of Frank Hofmann's v5 hibernation patchset.

Acked-by: Russ Dill <Russ.Dill@ti.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Sebastian Capella <sebastian.capella@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[fixed duplicate virt_to_pfn() definition --rmk]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Conflicts:
	arch/arm/kernel/Makefile
	include/linux/suspend.h
Cpufreq: interactive: Check actual freq before setting new freq

In case Actual freq is not updated till next timer interrupt
and new target freq comes same as actual freq.
Don't go for setting same frequency again.

Bug 1316765

Reviewed-on: http://git-master/r/249103
(cherry picked from commit d5a4d9622c27db40334ba2df3503c2d2e7457bcb)

Change-Id: If81786911fd85adb8469b49c59f2ab70ae12f96a
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Puneet Saxena <puneets@nvidia.com>
Reviewed-on: http://git-master/r/254352
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
Cpufreq: hellsactive: Check actual freq before setting new freq

In case Actual freq is not updated till next timer interrupt
and new target freq comes same as actual freq.
Don't go for setting same frequency again.

Bug 1316765

Reviewed-on: http://git-master/r/249103
(cherry picked from commit d5a4d9622c27db40334ba2df3503c2d2e7457bcb)

Change-Id: If81786911fd85adb8469b49c59f2ab70ae12f96a
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Signed-off-by: Puneet Saxena <puneets@nvidia.com>
Reviewed-on: http://git-master/r/254352
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Sachin Nikam <snikam@nvidia.com>
hells_defconfig: hC-b6.8