Merge remote-tracking branch 'lsk/v3.10/topic/arm64-kgdb' into linux-linaro-lsk

Conflicts:
arch/arm64/Kconfig
arch/arm64/include/asm/debug-monitors.h
arch/arm64/kernel/Makefile
arch/arm64/kernel/debug-monitors.c

arm64: KGDB: Add KGDB config

Add HAVE_ARCH_KGDB for arm64 Kconfig

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 9529247db9ecfc5a723e17093614e7437ab0d5bd)
Signed-off-by: Mark Brown <broonie@linaro.org>
Conflicts:
arch/arm64/Kconfig

misc: debug: remove compilation warnings

typecast instruction_pointer macro to unsigned long to
resolve following compiler warnings like
warning: format '%lx' expects argument of type 'long unsigned int',
but argument 2 has type 'u64' [-Wformat]

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 58dcc204f18af2821f683b235bb376f9db2557f5)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: KGDB: Add step debugging support

Add KGDB software step debugging support for EL1 debug
in AArch64 mode.

KGDB registers step debug handler with debug monitor.
On receiving 'step' command from GDB tool, target enables
software step debugging and step address is updated in ELR.

Software Step debugging is disabled when 'continue' command
is received

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 44679a4f142b69ae0c68ed815a48bbd164827281)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: KGDB: Add Basic KGDB support

Add KGDB debug support for kernel debugging.
With this patch, basic KGDB debugging is possible.GDB register
layout is updated and GDB tool can establish connection with
target and can set/clear breakpoints.

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit bcf5763b0d58d20e288ac52f96cbd7788e262cac)
Signed-off-by: Mark Brown <broonie@linaro.org>
Conflicts:
arch/arm64/kernel/Makefile

arm64: Add macros to manage processor debug state

Add macros to enable and disable to manage PSTATE.D
for debugging. The macros local_dbg_save and local_dbg_restore
are moved to irqflags.h file

KGDB boot tests fail because of PSTATE.D is masked.
unmask it for debugging support

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit c7db4ff5d2b459a579d348532a92fd5885520ce6)
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-misc' into linux-linaro-lsk

arm64: mm: fix the function name in comment of cpu_do_switch_mm

Fix the function name of comment of cpu_do_switch_mm,
because cpu_do_switch_mm is the correct name.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 812944e91dbbfeadaeeb4443a5560a7f45648f0b)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: mm: fix the function name in comment of __flush_dcache_area

Fix the function name of comment of __flush_dcache_area,
because __flush_dcache_area is the correct name. Also,
the missing variable 'size' is added to the comment.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 03324e6e6e66ebd171d9b4b90fd6a2655980dc13)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: mm: use ubfm for dcache_line_size

Use 'ubfm' for the bitfield move instruction; thus, single
instruction can be used instead of two instructions, when
getting the minimum D-cache line size from CTR_EL0 register.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit bd5f6dc304a054ccdc8dab43bef5e41d9a575b61)
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-insn' into linux-linaro-lsk

Conflicts:
arch/arm64/kernel/Makefile
arch/arm64/kernel/module.c

arm64, jump label: optimize jump label implementation

Optimize jump label implementation for ARM64 by dynamically patching
kernel text.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 9732cafd9dc0206479be919baf0067239f0a63ca)
Signed-off-by: Mark Brown <broonie@linaro.org>
Conflicts:
arch/arm64/kernel/Makefile

arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functions

Introduce aarch64_insn_gen_{nop|branch_imm}() helper functions, which
will be used to implement jump label on ARM64.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 5c5bf25d4f7a950382f94fc120a5818197b48fe9)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: move encode_insn_immediate() from module.c to insn.c

Function encode_insn_immediate() will be used by other instruction
manipulate related functions, so move it into insn.c and rename it
as aarch64_insn_encode_immediate().

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit c84fced8d990dd86c523233d38b4685a52a4fc3f)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: module: ensure instruction is little-endian before manipulation

Relocations that require an instruction immediate to be re-encoded must
ensure that the instruction pattern is represented in a little-endian
format for the manipulation code to work correctly.

This patch converts the loaded instruction into native-endianess prior
to encoding and then converts back to little-endian byteorder before
updating memory.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 122e2fa0d310d262cb85cf0b003032e5d2bc2ae7)

Signed-off-by: Victor Kamensky <victor.kamensky@linaro.org>
(cherry picked from commit 36bada1e73f23f948283f97caf775f3428e56af8)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: introduce interfaces to hotpatch kernel and module code

Introduce three interfaces to patch kernel and module code:
aarch64_insn_patch_text_nosync():
patch code without synchronization, it's caller's responsibility
to synchronize all CPUs if needed.
aarch64_insn_patch_text_sync():
patch code and always synchronize with stop_machine()
aarch64_insn_patch_text():
patch code and synchronize with stop_machine() if needed

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit ae16480785de1da84f21d1698f304a52f9790c49)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: introduce basic aarch64 instruction decoding helpers

Introduce basic aarch64 instruction decoding helper
aarch64_get_insn_class() and aarch64_insn_hotpatch_safe().

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit b11a64a48ccc7ca0ceb33544206934fbd3cdbb22)
Signed-off-by: Mark Brown <broonie@linaro.org>
Conflicts:
arch/arm64/kernel/Makefile

arm64: arch_timer: Fix mismerge

Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-misc' into linux-linaro-lsk

arm64: Remove unused __data_loc variable

The __data_loc variable is an unused left over from the 32 bit arm implementation.
Remove that variable and adjust the __mmap_switched startup routine accordingly.

Signed-off-by: Geoff Levand <geoff@infradead.org> for Huawei, Linaro
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit b22cf637bbaf99d4caf9908997a32f91cdcfae52)
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-ptrace' into linux-linaro-lsk

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-crypto' into linux-linaro-lsk

Conflicts:
arch/arm64/include/asm/arch_timer.h
arch/arm64/include/asm/hwcap.h
arch/arm64/include/uapi/asm/hwcap.h
arch/arm64/kernel/setup.c

arm64: advertise ARMv8 extensions to 32-bit compat ELF binaries

This adds support for advertising the presence of ARMv8 Crypto
Extensions in the Aarch32 execution state to 32-bit ELF binaries
running in 32-bit compat mode under the arm64 kernel.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 4cf761cdccc3b050f768f25dc36342cdfec4efdd)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: add AT_HWCAP2 support for 32-bit compat

Add support for the ELF auxv entry AT_HWCAP2 when running 32-bit
ELF binaries in compat mode.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 28964d32d495a0753986d464c48c8e1ae73699be)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Add hwcaps for crypto and CRC32 extensions.

Advertise the optional cryptographic and CRC32 instructions to
user space where present. Several hwcap bits [3-7] are allocated.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
[bit 2 is taken now so use bits 3-7 instead]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 4bff28ccda2b7a3fbdf8e80aef7a599284681dc6)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: drop redundant macros from read_cpuid()

asm/cputype.h contains a bunch of #defines for CPU id registers
that essentially map to themselves. Remove the #defines and pass
the tokens directly to the inline asm() that reads the registers.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 148eb0a1db8e37a5966afe98223cefe0c1837c26)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Remove outdated comment

Code referenced in the comment has moved to arch/arm64/kernel/cputable.c

Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 81cac699440fc3707fd80f16bf34a7e506d41487)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: support single-step and breakpoint handler hooks

AArch64 Single Steping and Breakpoint debug exceptions will be
used by multiple debug framworks like kprobes & kgdb.

This patch implements the hooks for those frameworks to register
their own handlers for handling breakpoint and single step events.

Reworked the debug exception handler in entry.S: do_dbg to route
software breakpoint (BRK64) exception to do_debug_exception()

Signed-off-by: Sandeepa Prabhu <sandeepa.prabhu@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit ee6214cec7818867f368c35843ea1f3dffcbb57c)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: debug: consolidate software breakpoint handlers

The software breakpoint handlers are hooked in directly from ptrace,
which makes it difficult to add additional handlers for things like
kprobes and kgdb.

This patch moves the handling code into debug-monitors.c, where we can
dispatch to different debug subsystems more easily.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 1442b6ed249d2b3d2cfcf45b65ac64393495c96c)
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge tag 'v3.10.40' into linux-linaro-lsk

This is the 3.10.40 stable release

Merge remote-tracking branch 'lsk/v3.10/topic/devm' into linux-linaro-lsk

devres: restore zeroing behavior of devres_alloc()

commit 64c862a8 (devres: add kernel standard devm_k.alloc functions) changed
the default behavior of alloc_dr() to no longer zero the allocated memory.  However,
only the devm.k.alloc() function were modified to pass in __GFP_ZERO which leaves
any users of devres_alloc() or __devres_alloc() with potentially wrong assumptions
about memory being zero'd upon allocation.

To fix, add __GFP_ZERO to devres_alloc() calls to preserve previous
behavior of zero'ing memory upon allocation.

Signed-off-by: Kevin Hilman <khilman@linaro.org>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 6fffcfa7c0fc438d3667b4eb2074d94f69c12c7b)
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

devres: add kernel standard devm_k.alloc functions

Currently, devm_ managed memory only supports kzalloc.

Convert the devm_kzalloc implementation to devm_kmalloc and remove the
complete memset to 0 but still set the initial struct devres header and
whatever padding before data to 0.

Add the other normal alloc variants as static inlines with __GFP_ZERO
added to the gfp flag where appropriate:

devm_kzalloc
devm_kcalloc
devm_kmalloc_array

Add gfp.h to device.h for the newly added static inlines.

akpm: the current API forces us to replace kmalloc() with kzalloc() when
performing devm_ conversions.  This adds a relatively minor overhead.
More significantly, it will defeat kmemcheck used-uninitialized checking,
and for a particular driver, losing used-uninitialised checking for their
core controlling data structures will significantly degrade kmemcheck
usefulness.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Sangjung Woo <sangjung.woo@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 64c862a839a8db2c02bbaa88b923d13e1208919d)
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/configs' into linux-linaro-lsk

configs: Make cpufreq not set for RT

Not sure this is going to do the right thing but it fixes errors that
the CI sees.  Why isn't the RT testing just setting the performance
governor anyway?

Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-perf' into linux-linaro-lsk

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-misc' into linux-linaro-lsk

Conflicts:
arch/arm64/Kconfig

arm64: perf: add support for percpu pmu interrupt

Add support for irq registration when pmu interrupt is percpu.

Signed-off-by: Vinayak Kale <vkale@apm.com>
Signed-off-by: Tuan Phan <tphan@apm.com>
[will: tidied up cross-calling to pass &irq]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 66aa8d6a145b6a66566b4fce219cc56c3d0e01c3)
Signed-off-by: Mark Brown <broonie@linaro.org>

genirq: Add an accessor for IRQ_PER_CPU flag

This patch adds an accessor function for IRQ_PER_CPU flag.
The accessor function is useful to determine whether an IRQ is percpu or not.

This patch is based on an older patch posted by Chris Smith here [1].
There is a minor change w.r.t. Chris's original patch: The accessor function
is renamed as 'irq_is_percpu' instead of 'irq_is_per_cpu'.

[1]: http://lkml.indiana.edu/hypermail/linux/kernel/1207.3/02955.html

Signed-off-by: Chris Smith <chris.smith@st.com>
Signed-off-by: Vinayak Kale <vkale@apm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 7f4a8e7b1943c1fc7e4b08509e308197babdcd5b)
Signed-off-by: Mark Brown <broonie@linaro.org>

ARM64: fix framepointer check in unwind_frame

We need at least 24 bytes above frame pointer.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 26920dd2da79a3207803da9453c0e6c82ac968ca)
Signed-off-by: Mark Brown <broonie@linaro.org>

ARM64: check stack pointer in get_wchan

get_wchan() is lockless. Task may wakeup at any time and change its own stack,
thus each next stack frame may be overwritten and filled with random stuff.

Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 408c3658b0d49315974ce8b5aed385c8e1527595)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: kconfig: select HAVE_EFFICIENT_UNALIGNED_ACCESS

ARMv8 CPUs can perform efficient unaligned memory accesses in hardware
and this feature is relied up on by code such as the dcache
word-at-a-time name hashing.

This patch selects HAVE_EFFICIENT_UNALIGNED_ACCESS for arm64.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 50afc33a90e710c02d9bbf2f3673936365f0e690)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: dcache: select DCACHE_WORD_ACCESS for little-endian CPUs

DCACHE_WORD_ACCESS uses the word-at-a-time API for optimised string
comparisons in the vfs layer.

This patch implements support for load_unaligned_zeropad in much the
same way as has been done for ARM, although big-endian systems are also
supported.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 7bc13fd33adb9536bd73965cd46bbf7377df097c)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: futex: ensure .fixup entries are sufficiently aligned

AArch64 instructions must be 4-byte aligned, so make sure this is true
for the futex .fixup section.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 4da7a56c59f28e27e8dcff61b5d7b05f6e203606)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: use generic strnlen_user and strncpy_from_user functions

This patch implements the word-at-a-time interface for arm64 using the
same algorithm as ARM. We use the fls64 macro, which expands to a clz
instruction via a compiler builtin. Big-endian configurations make use
of the implementation from asm-generic.

With this implemented, we can replace our byte-at-a-time strnlen_user
and strncpy_from_user functions with the optimised generic versions.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 12a0ef7b0ac38677bd2d85f33df5ca0a57868819)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: percpu: implement optimised pcpu access using tpidr_el1

This patch implements optimised percpu variable accesses using the
el1 r/w thread register (tpidr_el1) along the same lines as arch/arm/.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 7158627686f02319c50c8d9d78f75d4c8d126ff2)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: ptrace: avoid using HW_BREAKPOINT_EMPTY for disabled events

Commit 8f34a1da35ae ("arm64: ptrace: use HW_BREAKPOINT_EMPTY type for
disabled breakpoints") fixed an issue with GDB trying to zero breakpoint
control registers. The problem there is that the arch hw_breakpoint code
will attempt to create a (disabled), execute breakpoint of length 0.

This will fail validation and report unexpected failure to GDB. To avoid
this, we treated disabled breakpoints as HW_BREAKPOINT_EMPTY, but that
seems to have broken with recent kernels, causing watchpoints to be
treated as TYPE_INST in the core code and returning ENOSPC for any
further breakpoints.

This patch fixes the problem by prioritising the `enable' field of the
breakpoint: if it is cleared, we simply update the perf_event_attr to
indicate that the thing is disabled and don't bother changing either the
type or the length. This reinforces the behaviour that the breakpoint
control register is essentially read-only apart from the enable bit
when disabling a breakpoint.

Cc: <stable@vger.kernel.org>
Reported-by: Aaron Liu <liucy214@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit cdc27c27843248ae7eb0df5fc261dd004eaa5670)
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-cpu' into lsk-v3.10-arm64-misc

Conflicts:
arch/arm64/kernel/smp.c

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-misc' into linux-linaro-lsk

Conflicts:
Documentation/arm64/tagged-pointers.txt
arch/arm64/Kconfig
arch/arm64/boot/dts/Makefile
arch/arm64/include/asm/arch_timer.h
arch/arm64/include/asm/elf.h
arch/arm64/include/asm/spinlock.h
arch/arm64/kernel/smp.c

arm64: make default NR_CPUS 8

Rather than continue to add per platform defaults, make the default a
likely common core count. 8 is also the default for x86.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 62aceb8ff4b3f442575eb7e23629da36020dca77)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: ensure completion of TLB invalidatation

Currently there is no dsb between the tlbi in __cpu_setup and the write
to SCTLR_EL1 which enables the MMU in __turn_mmu_on. This means that the
TLB invalidation is not guaranteed to have completed at the point
address translation is enabled, leading to a number of possible issues
including incorrect translations and TLB conflict faults.

This patch moves the tlbi in __cpu_setup above an existing dsb used to
synchronise I-cache invalidation, ensuring that the TLBs have been
invalidated at the point the MMU is enabled.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 3cea71bc6b470372ae407881b87128aadf0afec0)
Signed-off-by: Mark Brown <broonie@linaro.org>

ARM64: /proc/interrupts: display IPIs of online CPUs only

The non-IPI interrupts are displayed only for the online cpus from
show_interrupts in kernel/irq/proc.c before calling arch_show_interrupts().
As a result, the column headers and the IPI count don't match if any
CPU is offline.

This patch fixes show_ipi_list to display IPIs for online CPUs only.

Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 67317c2689567c24d18e0dd43ab6d409fd42dc6e)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: locks: Remove CONFIG_GENERIC_LOCKBREAK

Commit 52ea2a560a9d (arm64: locks: introduce ticket-based spinlock
implementation) introduces the arch_spin_is_contended() function making
CONFIG_GENERIC_LOCKBREAK unnecessary.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit 61c77e0802719efce8966619cdc4234de7f252c1)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: compat: Clear the IT state independent of the 32-bit ARM or Thumb-2 mode

The ARM architecture reference specifies that the IT state bits in the
PSR must be all zeros in ARM mode or behavior is unspecified. If an ARM
function is registered as a signal handler, and that signal is delivered
inside a block of instructions following an IT instruction, some of the
instructions at the beginning of the signal handler may be skipped if
the IT state bits of the Program Status Register are not cleared by the
kernel.

Signed-off-by: T.J. Purtell <tj@mobisocial.us>
[catalin.marinas@arm.com: code comment and commit log updated]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit aa62c2091129af81a172350b718eb35d5448cebc)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Use 42-bit address space with 64K pages

This patch expands the VA_BITS to 42 when the 64K page configuration is
enabled allowing 2TB kernel linear mapping. Linux still uses 2 levels of
page tables in this configuration with pgd now being a full page.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 847264fb7e73ade5b5e4b6eea3daa243a1f5217e)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: fix access to preempt_count from assembly code

preempt_count is defined as an int. Oddly enough, we access it
as a 64bit value. Things become interesting when running a BE
kernel, and looking at the current CPU number, which is stored
as an int next to preempt_count. Like in a per-cpu interrupt
handler, for example...

Using a 32bit access fixes the issue for good.

Cc: Matthew Leach <matthew.leach@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 717321fcb58ed95169bf344ae47ac6098ba5dfbe)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: use generic RW_DATA_SECTION macro in linker script

The .data section in the arm64 linker script currently lacks a
definition for page-aligned data. This leads to a .page_aligned
section being placed between the end of data and start of bss.
This patch corrects that by using the generic RW_DATA_SECTION
macro which includes support for page-aligned data.

Signed-off-by: Mark Salter <msalter@redhat.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 3c620626c0cd4cfca856d70a846398275b48a768)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: update 32-bit kuser helpers to ARMv8

This patch updates the barrier semantics in the kuser helper functions
to take advantage of the ARMv8 additions to AArch32, which are
guaranteed to be available in situations where these functions will be
called.

Note that this slightly changes the cmpxchg functions in that they are
no longer necessarily full barriers if they return 1. However, the
documentation only states they include their own barriers "as needed",
not that they are obligated to act as a full barrier for the caller.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
CC: Matthew Leach <matthew.leach@arm.com>
CC: Dave Martin <dave.martin@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit d0f38f9130b7683e39611c5a661349e301ee43c8)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Export __copy_in_user() to modules

This function may be called from loadable modules, so it needs
exporting.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Loc Ho <lho@apm.com>
(cherry picked from commit 2a3f912c782f2364f5e5813ab66ca6c92fb43acb)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: cmpxchg: implement cmpxchg64_relaxed

This patch introduces cmpxchg64_relaxed for arm64 using the existing
cmpxchg_local macro, which performs a cmpxchg operation (up to 64 bits)
without barrier semantics.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit cf10b79a7d88edc689479af989b3a88e9adf07ff)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: lockref: add support for lockless lockrefs using cmpxchg

Our spinlocks are only 32-bit (2x16-bit tickets) and our cmpxchg can
deal with 8-bytes (as one would hope!).

This patch wires up the cmpxchg-based lockless lockref implementation
for arm64.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 5686b06cea34e31ec0a549d9b5ac00776e8e8d6d)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: locks: introduce ticket-based spinlock implementation

This patch introduces a ticket lock implementation for arm64, along the
same lines as the implementation for arch/arm/.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 52ea2a560a9dba57fe5fd6b4726b1089751accf2)
Signed-off-by: Mark Brown <broonie@linaro.org>

clk: arm64: Add DTS clock entry for APM X-Gene Storm SoC

clk: arm64: Add DTS clock entry for APM X-Gene Storm SoC with reference to
reference, PCP PLL, SoC PLL, and Ethernet clocks.

Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
Signed-off-by: Vinayak Kale <vkale@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
(cherry picked from commit 3eb15d84e355f4ea1acf0eaba11ca173de342107)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Widen hwcap to be 64 bit

Under arm64 elf_hwcap is a 32 bit quantity, but it is stored in
a 64 bit auxiliary ELF field and glibc reads hwcap as 64 bit.

This patch widens elf_hwcap to be 64 bit.

Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 25804e6a96681d5d2142058948e218999e4f547c)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Correctly report LR and SP for compat tasks

When a task crashes and we print debugging information, ensure that
compat tasks show the actual AArch32 LR and SP registers rather than the
AArch64 ones.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 6ca68e802612c87c31aa83d50c37ed0d88774a46)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Make do_bad_area() function static

This function is only called from arch/arm64/mm/fault.c.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 59f67e16e6b79697241c3fd030e3da300377893e)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: mm: permit use of tagged pointers at EL0

TCR.TBI0 can be used to cause hardware address translation to ignore the
top byte of userspace virtual addresses. Whilst not especially useful in
standard C programs, this can be used by JITs to `tag' pointers with
various pieces of metadata.

This patch enables this bit for AArch64 Linux, and adds a new file to
Documentation/arm64/ which describes some potential caveats when using
tagged virtual addresses.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit d50240a5f6ceaf690a77b0fccb17be51cfa151c2)
Signed-off-by: Mark Brown <broonie@linaro.org>

Move the EM_ARM and EM_AARCH64 definitions to uapi/linux/elf-em.h

Signed-off-by: Dan Aloni <alonid@stratoscale.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 909e3ee4119f87b85c6e1b8534b2287ed1ea3ca2)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: delay: don't bother reporting bogomips in /proc/cpuinfo

We always use a timer-backed delay loop for arm64, so don't bother
reporting a bogomips value which appears to confuse some people.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 326b16db9f69fd0d279be873c6c00f88c0a4aad5)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Fix mapping of memory banks not ending on a PMD_SIZE boundary

The map_mem() function limits the current memblock limit to PGDIR_SIZE
(the initial swapper_pg_dir mapping) to avoid create_mapping()
allocating memory from unmapped areas. However, if the first block is
within PGDIR_SIZE and not ending on a PMD_SIZE boundary, when 4K page
configuration is enabled, create_mapping() will try to allocate a pte
page. Such page may be returned by memblock_alloc() from the end of such
bank (or any subsequent bank within PGDIR_SIZE) which is not mapped yet.

The patch limits the current memblock limit to the aligned end of the
first bank and gradually increases it as more memory is mapped. It also
ensures that the start of the first bank is aligned to PMD_SIZE to avoid
pte page allocation for this mapping.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: "Leizhen (ThunderTown, Euler)" <thunder.leizhen@huawei.com>
Tested-by: "Leizhen (ThunderTown, Euler)" <thunder.leizhen@huawei.com>
(cherry picked from commit e25208f77c2dad5a9f2ab3d3df61252a90b71afa)
Signed-off-by: Mark Brown <broonie@linaro.org>

Merge remote-tracking branch 'lsk/v3.10/topic/arm64-hugepages' into lsk-v3.10-arm64-misc

arm64: move elf notes into readonly segment

The current vmlinux.lds.S places the notes sections between the
end of rw data and start of bss. This means that _edata doesn't
really point to the end of data. Since notes are read-only, this
patch moves them to the read-only segment so that _edata does
point to the end of initialized rw data.

Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit c80b7ee8520606f77fbc8ced870c96659053269e)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Enable interrupts in the EL0 undef handler

do_undefinstr() has to be called with interrupts disabled since it may
read the instruction from the user address space which could lead to a
data abort and subsequent might_sleep() warning in do_page_fault().

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 2600e130b3c90c8d6c13229d3d3a14dcb898a87b)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Expand arm64 image header

Expand the arm64 image header to allow for co-existance with
PE/COFF header required by the EFI stub.  The PE/COFF format
requires the "MZ" header to be at offset 0, and the offset
to the PE/COFF header to be at offset 0x3c.  The image
header is expanded to allow 2 instructions at the beginning
to accommodate a benign intruction at offset 0 that includes
the "MZ" header, a magic number, and the offset to the PE/COFF
header.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 4370eec05a887b0cd4392cd5dc5b2713174745c0)
Signed-off-by: Mark Brown <broonie@linaro.org>

ARM64: include: asm: include "asm/types.h" in "pgtable-2level-types.h" and "pgtable-3level-types.h"

Need include "asm/types.h", just like arm has done, or can not pass
compiling, the related error:

  In file included from arch/arm64/include/asm/page.h:37:0,
                   from drivers/staging/lustre/include/linux/lnet/linux/lib-lnet.h:42,
                   from drivers/staging/lustre/include/linux/lnet/lib-lnet.h:44,
                   from drivers/staging/lustre/lnet/lnet/api-ni.c:38:
  arch/arm64/include/asm/pgtable-2level-types.h:19:1: error: unknown type name ‘u64
  arch/arm64/include/asm/pgtable-2level-types.h:20:1: error: unknown type name ‘u64’

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 360b35a874f130305715b1b854b67dc40826fc91)
Signed-off-by: Mark Brown <broonie@linaro.org>

of: Specify initrd location using 64-bit

On some PAE architectures, the entire range of physical memory could reside
outside the 32-bit limit.  These systems need the ability to specify the
initrd location using 64-bit numbers.

This patch globally modifies the early_init_dt_setup_initrd_arch() function to
use 64-bit numbers instead of the current unsigned long.

There has been quite a bit of debate about whether to use u64 or phys_addr_t.
It was concluded to stick to u64 to be consistent with rest of the device
tree code. As summarized by Geert, "The address to load the initrd is decided
by the bootloader/user and set at that point later in time. The dtb should not
be tied to the kernel you are booting"

More details on the discussion can be found here:
https://lkml.org/lkml/2013/6/20/690
https://lkml.org/lkml/2012/9/13/544

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
(cherry picked from commit 374d5c9964c10373ba39bbe934f4262eb87d7114)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
and it can work independent with 'COMPAT', so remove dummy definition.

The related error:

  arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ‘aarch32_break_handler’
  In file included from arch/arm64/kernel/debug-monitors.c:29:0:
  /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ‘aarch32_break_handler’ was here

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit c783c2815e13bbb0c0b99997cc240bd7e91b6bb8)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Add initial DTS for APM X-Gene Storm SOC and APM Mustang board

This patch adds initial DTS files required for APM Mustang board.

Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit ee877b5321c4dfee9dc9f2a12b19ddcd33149f6a)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Add defines for APM ARMv8 implementation

This patch adds defines for APM CPU implementer ID and APM CPU part numbers in asm/cputype.h

Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 4ad637a452d5683ca7ff9e9eb994ac4b7a517073)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Enable APM X-Gene SOC family in the defconfig

This patch enables APM X-Gene SOC family in the defconfig. It also enables 8250 serial driver needed by X-Gene SOC family.

Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit c1db16dc9e74addba4ef8c954702f13e457f0c7e)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Add Kconfig option for APM X-Gene SOC family

This patch adds arm64/Kconfig option for APM X-Gene SOC family.

Signed-off-by: Kumar Sankaran <ksankaran@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 159428538323188158a6058956c16c199909d844)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64/Makefile: provide vdso_install target

Provide a vdso_install target in the arm64 Makefile, as other architectures
with a vdso do.

Signed-off-by: Kyle McMartin <kyle@redhat.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 3c01742a8ac93a3abf9b099758db970410427afd)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: debug: consolidate software breakpoint handlers

The software breakpoint handlers are hooked in directly from ptrace,
which makes it difficult to add additional handlers for things like
kprobes and kgdb.

This patch moves the handling code into debug-monitors.c, where we can
dispatch to different debug subsystems more easily.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 1442b6ed249d2b3d2cfcf45b65ac64393495c96c)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: extable: sort the exception table at build time

As is done for other architectures, sort the exception table at
build-time rather than during boot.

Since sortextable appears to be a standalone C program relying on the
host elf.h to provide EM_AARCH64, I've had to add a conditional check in
order to allow cross-compilation on machines that aren't running a
bleeding-edge libc-dev.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit adace89562c7a9645b8dc84f6e1ac7ba8756094e)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: device: add iommu pointer to device archdata

When using an IOMMU for device mappings, it is necessary to keep a
pointer between the device and the IOMMU to which it is attached in
order to obtain the correct IOMMU when attaching the device to a domain.

This patch adds an iommu pointer to the dev_archdata structure, in a
similar manner to other architectures (ARM, PowerPC, x86, ...).

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 73150c983ac1f9b7653cfd3823b1ad4a44aad3bf)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: pgtable: use pte_index instead of __pte_index

pte_index is a useful helper outside of arch/arm64, for things like the
ARM SMMU driver, so rename __pte_index to pte_index to be consistent
with both arch/arm/ and also the definitions of pmd_index and pgd_index.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 9ab6d02fddc6831b166812956ff387d7112ff626)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: kernel: compiling issue, need delete read_current_timer()

Under arm64, we will calibrate the delay loop statically using a known
timer frequency, so delete read_current_timer(), or it will cause
compiling issue with allmodconfig.

The related error:
  ERROR: "read_current_timer" [lib/rbtree_test.ko] undefined!
  ERROR: "read_current_timer" [lib/interval_tree_test.ko] undefined!
  ERROR: "read_current_timer" [fs/ext4/ext4.ko] undefined!
  ERROR: "read_current_timer" [crypto/tcrypt.ko] undefined!

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 6916b14ea140ff5c915895eefe9431888a39a84d)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: mm: don't bother invalidating the icache in switch_mm

We don't support software broadcast of cache maintenance operations, so
this flush is not required (__sync_icache_dcache will always affect all
CPUs).

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 737c16dffc458e58ee7840556d43b874cb8e16a0)
Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: Fix build for __PAGE_NONE define

Simple typo.

Signed-off-by: Mark Brown <broonie@linaro.org>

arm64: mm: Add double logical invert to pte accessors

Page table entries on ARM64 are 64 bits, and some pte functions such as
pte_dirty return a bitwise-and of a flag with the pte value. If the
flag to be tested resides in the upper 32 bits of the pte, then we run
into the danger of the result being dropped if downcast.

For example:
gather_stats(page, md, pte_dirty(*pte), 1);
where pte_dirty(*pte) is downcast to an int.

This patch adds a double logical invert to all the pte_ accessors to
ensure predictable downcasting.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: mm: Introduce PTE_WRITE

We have the following means for encoding writable or dirty ptes:

                                PTE_DIRTY       PTE_RDONLY
!pte_dirty && !pte_write        0               1
!pte_dirty && pte_write         0               1
pte_dirty && !pte_write         1               1
pte_dirty && pte_write          1               0

So we can't distinguish between writable clean ptes and read only
ptes. This can cause problems with ptes being incorrectly flagged as
read only when they are writable but not dirty.

This patch introduces a new software bit PTE_WRITE which allows us to
correctly identify writable ptes. PTE_RDONLY is now only clear for
valid ptes where a page is both writable and dirty.

Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Conflicts:
arch/arm64/include/asm/pgtable.h

arm64: mm: Remove PTE_BIT_FUNC macro

Expand out the pte manipulation functions. This makes our life easier
when using things like tags and cscope.

Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

mm/hugetlb.c: call MMU notifiers when copying a hugetlb page range

When copy_hugetlb_page_range() is called to copy a range of hugetlb
mappings, the secondary MMUs are not notified if there is a protection
downgrade, which breaks COW semantics in KVM.

This patch adds the necessary MMU notifier calls.

Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
Acked-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arm64: mm: Fix PMD_SECT_PROT_NONE definition

Modify the value of PMD_SECT_PROT_NONE to match that of PTE_NONE. This
should have been in commit 3676f9ef5481 (Move PTE_PROT_NONE higher up).

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org> # 3.11+: 3676f9ef5481: arm64: Move PTE_PROT_NONE higher up
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: Move PTE_PROT_NONE higher up

PTE_PROT_NONE means that a pte is present but does not have any
read/write attributes. However, setting the memory type like
pgprot_writecombine() is allowed and such bits overlap with
PTE_PROT_NONE. This causes mmap/munmap issues in drivers that change the
vma->vm_pg_prot on PROT_NONE mappings.

This patch reverts the PTE_FILE/PTE_PROT_NONE shift in commit
59911ca4325d (ARM64: mm: Move PTE_PROT_NONE bit) and moves PTE_PROT_NONE
together with the other software bits.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Steve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org> # 3.11+

ARM64: mm: THP support.

Bring Transparent HugePage support to ARM. The size of a
transparent huge page depends on the normal page size. A
transparent huge page is always represented as a pmd.

If PAGE_SIZE is 4KB, THPs are 2MB.
If PAGE_SIZE is 64KB, THPs are 512MB.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

ARM64: mm: Raise MAX_ORDER for 64KB pages and THP.

The buddy allocator has a default MAX_ORDER of 11, which is too
low to allocate enough memory for 512MB Transparent HugePages if
our base page size is 64KB.

This patch introduces MAX_ZONE_ORDER and sets it to 14 when 64KB
pages are used in conjuction with THP, otherwise the default value
of 11 is used.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

ARM64: mm: HugeTLB support.

Add huge page support to ARM64, different huge page sizes are
supported depending on the size of normal pages:

PAGE_SIZE is 4KB:
   2MB - (pmds) these can be allocated at any time.
1024MB - (puds) usually allocated on bootup with the command line
         with something like: hugepagesz=1G hugepages=6

PAGE_SIZE is 64KB:
 512MB - (pmds) usually allocated on bootup via command line.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

ARM64: mm: Move PTE_PROT_NONE bit.

Under ARM64, PTEs can be broadly categorised as follows:
   - Present and valid: Bit #0 is set. The PTE is valid and memory
     access to the region may fault.

   - Present and invalid: Bit #0 is clear and bit #1 is set.
     Represents present memory with PROT_NONE protection. The PTE
     is an invalid entry, and the user fault handler will raise a
     SIGSEGV.

   - Not present (file or swap): Bits #0 and #1 are clear.
     Memory represented has been paged out. The PTE is an invalid
     entry, and the fault handler will try and re-populate the
     memory where necessary.

Huge PTEs are block descriptors that have bit #1 clear. If we wish
to represent PROT_NONE huge PTEs we then run into a problem as
there is no way to distinguish between regular and huge PTEs if we
set bit #1.

To resolve this ambiguity this patch moves PTE_PROT_NONE from
bit #1 to bit #2 and moves PTE_FILE from bit #2 to bit #3. The
number of swap/file bits is reduced by 1 as a consequence, leaving
60 bits for file and swap entries.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

ARM64: mm: Make PAGE_NONE pages read only and no-execute.

If we consider the following code sequence:

my_pte = pte_modify(entry, myprot);
x = pte_write(my_pte);
y = pte_exec(my_pte);

If myprot comes from a PROT_NONE page, then x and y will both be
true which is undesireable behaviour.

This patch sets the no-execute and read-only bits for PAGE_NONE
such that the code above will return false for both x and y.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>