On platforms implementing CPU power management, the CPUidle subsystem
can allow CPUs to enter idle states where local timers logic is lost on power
down. To keep the software timers functional the kernel relies on an
always-on broadcast timer to be present in the platform to relay the
interrupt signalling the timer expiries.

For platforms implementing CPU core gating that do not implement an always-on
HW timer or implement it in a broken way, this patch adds code to initialize
the kernel hrtimer based clock event device upon boot (which can be chosen as
tick broadcast device by the kernel).
It relies on a dynamically chosen CPU to be always powered-up. This CPU then
relays the timer interrupt to CPUs in deep-idle states through its HW local
timer device.

Having a CPU always-on has implications on power management platform
capabilities and makes CPUidle suboptimal, since at least a CPU is kept
always in a shallow idle state by the kernel to relay timer interrupts,
but at least leaves the kernel with a functional system with some working
power management capabilities.

The hrtimer based clock event device is unconditionally registered, but
has the lowest possible rating such that any broadcast-capable HW clock
event device present will be chosen in preference as the tick broadcast
device.

Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

This patch allows system call entry or exit to be traced as ftrace events,
ie. sys_enter_*/sys_exit_*, if CONFIG_FTRACE_SYSCALLS is enabled.
Those events appear and can be controlled under
    ${sysfs}/tracing/events/syscalls/

Please note that we can't trace compat system calls here because
AArch32 mode does not share the same syscall table with AArch64.
Just define ARCH_TRACE_IGNORE_COMPAT_SYSCALLS in order to avoid unexpected
results (bogus syscalls reported or even hang-up).

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

CALLER_ADDRx returns caller's address at specified level in call stacks.
They are used for several tracers like irqsoff and preemptoff.
Strange to say, however, they are refered even without FTRACE.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

This patch allows "dynamic ftrace" if CONFIG_DYNAMIC_FTRACE is enabled.
Here we can turn on and off tracing dynamically per-function base.

On arm64, this is done by patching single branch instruction to _mcount()
inserted by gcc -pg option. The branch is replaced to NOP initially at
kernel start up, and later on, NOP to branch to ftrace_caller() when
enabled or branch to NOP when disabled.
Please note that ftrace_caller() is a counterpart of _mcount() in case of
'static' ftrace.

More details on architecture specific requirements are described in
Documentation/trace/ftrace-design.txt.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

This patch implements arm64 specific part to support function tracers,
such as function (CONFIG_FUNCTION_TRACER), function_graph
(CONFIG_FUNCTION_GRAPH_TRACER) and function profiler
(CONFIG_FUNCTION_PROFILER).

With 'function' tracer, all the functions in the kernel are traced with
timestamps in ${sysfs}/tracing/trace. If function_graph tracer is
specified, call graph is generated.

The kernel must be compiled with -pg option so that _mcount() is inserted
at the beginning of functions. This function is called on every function's
entry as long as tracing is enabled.
In addition, function_graph tracer also needs to be able to probe function's
exit. ftrace_graph_caller() & return_to_handler do this by faking link
register's value to intercept function's return path.

More details on architecture specific requirements are described in
Documentation/trace/ftrace-design.txt.

Reviewed-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Recordmcount utility under scripts is run, after compiling each object,
to find out all the locations of calling _mcount() and put them into
specific seciton named __mcount_loc.
Then linker collects all such information into a table in the kernel image
(between __start_mcount_loc and __stop_mcount_loc) for later use by ftrace.

This patch adds arm64 specific definitions to identify such locations.
There are two types of implementation, C and Perl. On arm64, only C version
is used to build the kernel now that CONFIG_HAVE_C_RECORDMCOUNT is on.
But Perl version is also maintained.

This patch also contains a workaround just in case where a header file,
elf.h, on host machine doesn't have definitions of EM_AARCH64 nor
R_AARCH64_ABS64. Without them, compiling C version of recordmcount will
fail.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

walk_stackframe() calls unwind_frame(), and if walk_stackframe() is
"notrace", unwind_frame() should be also "notrace".

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Since insn.h is indirectly included in asm/entry-ftrace.S,
we need to exclude some declarations by __ASSEMBLY__.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Merge branch 'ftrace/arm64' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into for-next/core

Core ftrace changes from Steve Rostedt, required by the arm64 support
code.

Change the arm64 linker script ENTRY() command to define _text as the
kernel entry point.

The arm64 boot protocol specifies that the kernel must be entered at the
beginning of the kernel image.  The existing ENTRY() command defined the
symbol stext as the entry point, which emitted an incorrect entry point,
but would not cause a runtime error because the existing entry code
immediately jumps to stext.

Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch, based on Linaro's Cortex Strings library, adds
an assembly optimized strlen() and strnlen() functions.

Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch, based on Linaro's Cortex Strings library, adds
an assembly optimized strcmp() and strncmp() functions.

Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch, based on Linaro's Cortex Strings library, adds
an assembly optimized memcmp() function.

Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch, based on Linaro's Cortex Strings library, improves
the performance of the assembly optimized memset() function.

Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch, based on Linaro's Cortex Strings library, improves
the performance of the assembly optimized memmove() function.

Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch, based on Linaro's Cortex Strings library, improves
the performance of the assembly optimized memcpy() function.

Signed-off-by: Zhichang Yuan <zhichang.yuan@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Whilst our defconfig is certainly usable, there are a few extra features
we can enable to make it considerably more useful, particularly if
people are using it for testing:

 - KVM
 - SWAP
 - Hugepages
 - ARMv8 crypto

This patch enables these options in our defconfig. Note that the ordering
has changed slightly, since this is the result of a new savedefconfig
make target.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Most archs with HAVE_ARCH_CALLER_ADDR have pretty much the same
definitions of CALLER_ADDRx(n). Instead of duplicating the code for all
the archs, define a ftrace_return_address0() and
ftrace_return_address(n) that can be overwritten by the archs if they
need to do something different. Instead of 7 macros in every arch, we
now only have at most 2 (and actually only 1 as
ftrace_return_address0() should be the same for all archs).

The CALLER_ADDRx(n) will now be defined in linux/ftrace.h and use the
ftrace_return_address*(n?) macros. This removes a lot of the duplicate
code.

Link: http://lkml.kernel.org/p/1400585464-30333-1-git-send-email-takahiro.akashi@linaro.org



Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

If one process calls sys_reboot and that process then stops other
CPUs while those CPUs are within a spin_lock() region we can
potentially encounter a deadlock scenario like below.

CPU 0                   CPU 1
-----                   -----
                        spin_lock(my_lock)
smp_send_stop()
 <send IPI>             handle_IPI()
                         disable_preemption/irqs
                          while(1);
 <PREEMPT>
spin_lock(my_lock) <--- Waits forever

We shouldn't attempt to run any other tasks after we send a stop
IPI to a CPU so disable preemption so that this task runs to
completion. We use local_irq_disable() here for cross-arch
consistency with x86.

Based-on-work-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Arun KS <getarunks@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch ports most of commit 19ab428f

 "ARM: 7759/1: decouple CPU
offlining from reboot/shutdown" by Stephen Warren from arch/arm to
arch/arm64.

machine_shutdown() is a hook for kexec. Add a comment saying so, since
it isn't obvious from the function name.

Halt, power-off, and restart have different requirements re: stopping
secondary CPUs than kexec has. The former simply require the secondary
CPUs to be quiesced somehow, whereas kexec requires them to be
completely non-operational, so that no matter where the kexec target
images are written in RAM, they won't influence operation of the
secondary CPUS,which could happen if the CPUs were still executing some
kind of pin loop. To this end, modify machine_halt, power_off, and
restart to call smp_send_stop() directly, rather than calling
machine_shutdown().

In machine_shutdown(), replace the call to smp_send_stop() with a call
to disable_nonboot_cpus(). This completely disables all but one CPU,
thus satisfying the kexec requirements a couple paragraphs above.

Signed-off-by: Arun KS <getarunks@gmail.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Support for arch_irq_work_raise() was missing from
arm64 (a prerequisite for FULL_NOHZ).

This patch is based on the arm32 patch ARM 7872/1.

commit bf18525f


Author: Stephen Boyd <sboyd@codeaurora.org>
Date:   Tue Oct 29 20:32:56 2013 +0100

    ARM: 7872/1: Support arch_irq_work_raise() via self IPIs

    By default, IRQ work is run from the tick interrupt (see
    irq_work_run() in update_process_times()). When we're in full
    NOHZ mode, restarting the tick requires the use of IRQ work and
    if the only place we run IRQ work is in the tick interrupt we
    have an unbreakable cycle. Implement arch_irq_work_raise() via
    self IPIs to break this cycle and get the tick started again.
    Note that we implement this via IPIs which are only available on
    SMP builds. This shouldn't be a problem because full NOHZ is only
    supported on SMP builds anyway.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: Larry Bassel <larry.bassel@linaro.org>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add support for parsing the explicit topology bindings to discover the
topology of the system.

Since it is not currently clear how to map multi-level clusters for the
scheduler all leaf clusters are presented to the scheduler at the same
level. This should be enough to provide good support for current systems.

Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

As a legacy of the way 32 bit ARM did things the topology code uses a null
topology map by default and then overwrites it by mapping cores with no
information to a cluster by themselves later. In order to make it simpler
to reset things as part of recovering from parse failures in firmware
information directly set this configuration on init. A core will always be
its own sibling so there should be no risk of confusion with firmware
provided information.

Signed-off-by: Mark Brown <broonie@linaro.org>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Remove unused and deprecated mc_capable() and smt_capable().

Both were added recently by f6e763b9 ("arm64: topology:
Implement basic CPU topology support"). Uses of both were removed
by 8e7fbcbc

 ("sched: Remove stale power aware scheduling
remnants and dysfunctional knobs").

Signed-off-by: Zi Shen Lim <zlim@broadcom.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This reverts commit bc07c2c6

.

While the aim is increased security for --x memory maps, it does not
protect against kernel level reads. Until SECCOMP is implemented for
arm64, revert this patch to avoid giving a false idea of execute-only
mappings.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

FPSIMD register bank context switching and crypto algorithms
optimisations for arm64 from Ard Biesheuvel.

* tag 'for-3.16' of git://git.linaro.org/people/ard.biesheuvel/linux-arm:
  arm64/crypto: AES-ECB/CBC/CTR/XTS using ARMv8 NEON and Crypto Extensions
  arm64: pull in <asm/simd.h> from asm-generic
  arm64/crypto: AES in CCM mode using ARMv8 Crypto Extensions
  arm64/crypto: AES using ARMv8 Crypto Extensions
  arm64/crypto: GHASH secure hash using ARMv8 Crypto Extensions
  arm64/crypto: SHA-224/SHA-256 using ARMv8 Crypto Extensions
  arm64/crypto: SHA-1 using ARMv8 Crypto Extensions
  arm64: add support for kernel mode NEON in interrupt context
  arm64: defer reloading a task's FPSIMD state to userland resume
  arm64: add abstractions for FPSIMD state manipulation
  asm-generic: allow generic unaligned access if the arch supports it

Conflicts:
	arch/arm64/include/asm/thread_info.h

This adds ARMv8 implementations of AES in ECB, CBC, CTR and XTS modes,
both for ARMv8 with Crypto Extensions and for plain ARMv8 NEON.

The Crypto Extensions version can only run on ARMv8 implementations that
have support for these optional extensions.

The plain NEON version is a table based yet time invariant implementation.
All S-box substitutions are performed in parallel, leveraging the wide range
of ARMv8's tbl/tbx instructions, and the huge NEON register file, which can
comfortably hold the entire S-box and still have room to spare for doing the
actual computations.

The key expansion routines were borrowed from aes_generic.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

This patch adds support for the AES-CCM encryption algorithm for CPUs that
have support for the AES part of the ARM v8 Crypto Extensions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

This patch adds support for the AES symmetric encryption algorithm for CPUs
that have support for the AES part of the ARM v8 Crypto Extensions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

This is a port to ARMv8 (Crypto Extensions) of the Intel implementation of the
GHASH Secure Hash (used in the Galois/Counter chaining mode). It relies on the
optional PMULL/PMULL2 instruction (polynomial multiply long, what Intel call
carry-less multiply).

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

This patch adds support for the SHA-224 and SHA-256 Secure Hash Algorithms
for CPUs that have support for the SHA-2 part of the ARM v8 Crypto Extensions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

This patch adds support for the SHA-1 Secure Hash Algorithm for CPUs that
have support for the SHA-1 part of the ARM v8 Crypto Extensions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>

Some kernel files may include both linux/compat.h and asm/compat.h directly
or indirectly. Since both header files contain is_compat_task() under
!CONFIG_COMPAT, compiling them with !CONFIG_COMPAT will eventually fail.
Such files include kernel/auditsc.c, kernel/seccomp.c and init/do_mountfs.c
(do_mountfs.c may read asm/compat.h via asm/ftrace.h once ftrace is
implemented).

So this patch proactively
1) removes is_compat_task() under !CONFIG_COMPAT from asm/compat.h
2) replaces asm/compat.h to linux/compat.h in kernel/*.c,
   but asm/compat.h is still necessary in ptrace.c and process.c because
   they use is_compat_thread().

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This macro, regs_return_value, is used mainly for audit to record system
call's results, but may also be used in test_kprobes.c.

Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

As done in arm, this change makes it easy to confirm we invoke syscall
related hooks, including syscall tracepoint, audit and seccomp which would
be implemented later, in correct order. That is, undoing operations in the
opposite order on exit that they were done on entry.

Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Currently syscall_trace() is called only for ptrace.
With additional TIF_xx flags defined, it is now called in all the cases
of audit, ftrace and seccomp in addition to ptrace.

Acked-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Since mdscr_el1 is part of the debug register group, it is highly likely
to be trapped by a hypervisor to prevent virtual machines from debugging
(buggering?) each other. Unfortunately, this absolutely destroys our
performance, since we access the register on many of our low-level
fault handling paths to keep track of the various debug state machines.

This patch removes our dependency on mdscr_el1 in the case that debugging
is not being used. More specifically we:

  - Use TIF_SINGLESTEP to indicate that a task is stepping at EL0 and
    avoid disabling step in the MDSCR when we don't need to.
    MDSCR_EL1.SS handling is moved to kernel_entry, when trapping from
    userspace.

  - Ensure debug exceptions are re-enabled on *all* exception entry
    paths, even the debug exception handling path (where we re-enable
    exceptions after invoking the handler). Since we can now rely on
    MDSCR_EL1.SS being cleared by the entry code, exception handlers can
    usually enable debug immediately before enabling interrupts.

  - Remove all debug exception unmasking from ret_to_user and
    el1_preempt, since we will never get here with debug exceptions
    masked.

This results in a slight change to kernel debug behaviour, where we now
step into interrupt handlers and data aborts from EL1 when debugging the
kernel, which is actually a useful thing to do. A side-effect of this is
that it *does* potentially prevent stepping off {break,watch}points when
there is a high-frequency interrupt source (e.g. a timer), so a debugger
would need to use either breakpoints or manually disable interrupts to
get around this issue.

With this patch applied, guest performance is restored under KVM when
debug register accesses are trapped (and we get a measurable performance
increase on the host on Cortex-A57 too).

Cc: Ian Campbell <ian.campbell@citrix.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Pull x86 fixes from Peter Anvin:
 "A somewhat unpleasantly large collection of small fixes.  The big ones
  are the __visible tree sweep and a fix for 'earlyprintk=efi,keep'.  It
  was using __init functions with predictably suboptimal results.

  Another key fix is a build fix which would produce output that simply
  would not decompress correctly in some configuration, due to the
  existing Makefiles picking up an unfortunate local label and mistaking
  it for the global symbol _end.

  Additional fixes include the handling of 64-bit numbers when setting
  the vdso data page (a latent bug which became manifest when i386
  started exporting a vdso with time functions), a fix to the new MSR
  manipulation accessors which would cause features to not get properly
  unblocked, a build fix for 32-bit userland, and a few new platform
  quirks"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, vdso, time: Cast tv_nsec to u64 for proper shifting in update_vsyscall()
  x86: Fix typo in MSR_IA32_MISC_ENABLE_LIMIT_CPUID macro
  x86: Fix typo preventing msr_set/clear_bit from having an effect
  x86/intel: Add quirk to disable HPET for the Baytrail platform
  x86/hpet: Make boot_hpet_disable extern
  x86-64, build: Fix stack protector Makefile breakage with 32-bit userland
  x86/reboot: Add reboot quirk for Certec BPC600
  asmlinkage: Add explicit __visible to drivers/*, lib/*, kernel/*
  asmlinkage, x86: Add explicit __visible to arch/x86/*
  asmlinkage: Revert "lto: Make asmlinkage __visible"
  x86, build: Don't get confused by local symbols
  x86/efi: earlyprintk=efi,keep fix