When a CPU resumes from low-power, it restores HW breakpoint and
watchpoint slots through a CPU PM notifier. Since we want to enable
debugging as early as possible in the resume path, the mdscr content
is restored along the general purpose registers in the cpu_suspend API
and debug exceptions are reenabled when cpu_suspend returns. Since the
CPU PM notifier is run after a CPU has been resumed, we cannot expect
HW breakpoint registers to contain sane values till the notifier is run,
since the HW breakpoints registers content is unknown at reset; this means
that the CPU might run with debug exceptions enabled, mdscr restored but HW
breakpoint registers containing junk values that can trigger spurious
debug exceptions.

This patch fixes current HW breakpoints restore by moving the HW breakpoints
registers restoration to the cpu_suspend API, before the debug exceptions are
enabled. This way, as soon as the cpu_suspend function returns the
kernel can resume debugging with sane values in HW breakpoint registers.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Use macro JUMP_LABEL_TRUE_BRANCH instead of hard-coding for better
readability.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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>

As commit a9468f30 "ARM: 7333/2: jump label: detect %c
support for ARM", this patch detects the same thing for ARM64
because some ARM64 GCC versions have the same issue.

Some versions of ARM64 GCC which do support asm goto, do not
support the %c specifier. Since we need the %c to support jump
labels on ARM64, detect that too in the asm goto detection script
to avoid build errors with these versions.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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>

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>

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>

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>

Will Deacon observed that kvmtool uses a size of 0x200 for virtio
block memory region and that the virtio block spec only uses 31 bytes in
the device specific region at 0x100 so reduce the region to a less
wasteful 0x200.
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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>

* tag 'arm64-suspend' of git://linux-arm.org/linux-2.6-lp:
  arm64: add CPU power management menu/entries
  arm64: kernel: add PM build infrastructure
  arm64: kernel: add CPU idle call
  arm64: enable generic clockevent broadcast
  arm64: kernel: implement HW breakpoints CPU PM notifier
  arm64: kernel: refactor code to install/uninstall breakpoints
  arm: kvm: implement CPU PM notifier
  arm64: kernel: implement fpsimd CPU PM notifier
  arm64: kernel: cpu_{suspend/resume} implementation
  arm64: kernel: suspend/resume registers save/restore
  arm64: kernel: build MPIDR_EL1 hash function data structure
  arm64: kernel: add MPIDR_EL1 accessors macros

Conflicts:
	arch/arm64/Kconfig

arm64 bit targets need the features CMA provides. Add the appropriate
hooks, header files, and Kconfig to allow this to happen.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Although parts of the DMA apis may properly check for NULL devices,
there may be some places that don't. Rather than fix up all the
possible locations, just require a non-NULL device structure to be
used for allocating/freeing.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
[catalin.marinas@arm.com: s/WARN/WARN_ONCE/]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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>

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>

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>

Make sure the value we are going to return is referenced in order to
avoid warnings from newer GCCs such as:

arch/arm64/include/asm/cmpxchg.h:162:3: warning: value computed is not used [-Wunused-value]
  ((__typeof__(*(ptr)))__cmpxchg_mb((ptr),   \
   ^
net/netfilter/nf_conntrack_core.c:674:2: note: in expansion of macro ‘cmpxchg’
  cmpxchg(&nf_conntrack_hash_rnd, 0, rand);

[Modified to use the current underlying implementation as current
mainline for both cmpxchg() and cmpxchg_local() does -- broonie]
Signed-off-by: Mark Hambleton <mahamble@broadcom.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

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>

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>

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>

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>

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>

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>

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>

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>

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>

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.htmlSigned-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>

We currently try to emit .comment twice, once in STABS_DEBUG, and once
in the line immediately following it. As the two section definitions are
identical, the latter is redundant and can be dropped.

This patch drops the redundant .comment section definition.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Describe the virtio device so we can mount disk images in the simulator.

[Reduced the size of the region based on feedback from review -- broonie]
Signed-off-by: Mark Hambleton <mahamble@broadcom.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The definition of virt_addr_valid is that virt_addr_valid should
return true if and only if virt_to_page returns a valid pointer.
The current definition of virt_addr_valid only checks against the
virtual address range. There's no guarantee that just because a
virtual address falls bewteen PAGE_OFFSET and high_memory the
associated physical memory has a valid backing struct page. Follow
the example of other architectures and convert to pfn_valid to
verify that the virtual address is actually valid.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

This patch provides a menu for CPU power management options in the
arm64 Kconfig and adds an entry to enable the generic CPU idle configuration.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

This patch adds the required makefile and kconfig entries to enable PM
for arm64 systems.

The kernel relies on the cpu_{suspend}/{resume} infrastructure to
properly save the context for a CPU and put it to sleep, hence this
patch adds the config option required to enable cpu_{suspend}/{resume}
API.

In order to rely on the CPU PM implementation for saving and restoring
of CPU subsystems like GIC and PMU, the arch Kconfig must be also
augmented to select the CONFIG_CPU_PM option when SUSPEND or CPU_IDLE
kernel implementations are selected.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

When CPU idle is enabled, the architectural idle call should go through
the idle subsystem to allow CPUs to enter idle states defined
by the platform CPU idle back-end operations.

This patch, mirroring other archs behaviour, adds the CPU idle call to the
architectural arch_cpu_idle implementation for arm64.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

On platforms with power management capabilities, timers that are shut
down when a CPU enters deep C-states must be emulated using an always-on
timer and a timer IPI to relay the timer IRQ to target CPUs on an SMP
system.

This patch enables the generic clockevents broadcast infrastructure for
arm64, by providing the required Kconfig entries and adding the timer
IPI infrastructure.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

When a CPU is shutdown either through CPU idle or suspend to RAM, the
content of HW breakpoint registers must be reset or restored to proper
values when CPU resume from low power states. This patch adds debug register
restore operations to the HW breakpoint control function and implements a
CPU PM notifier that allows to restore the content of HW breakpoint registers
to allow proper suspend/resume operations.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Most of the code executed to install and uninstall breakpoints is
common and can be factored out in a function that through a runtime
operations type provides the requested implementation.

This patch creates a common function that can be used to install/uninstall
breakpoints and defines the set of operations that can be carried out
through it.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Upon CPU shutdown and consequent warm-reboot, the hypervisor CPU state
must be re-initialized. This patch implements a CPU PM notifier that
upon warm-boot calls a KVM hook to reinitialize properly the hypervisor
state so that the CPU can be safely resumed.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

When a CPU enters a low power state, its FP register content is lost.
This patch adds a notifier to save the FP context on CPU shutdown
and restore it on CPU resume. The context is saved and restored only
if the suspending thread is not a kernel thread, mirroring the current
context switch behaviour.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Kernel subsystems like CPU idle and suspend to RAM require a generic
mechanism to suspend a processor, save its context and put it into
a quiescent state. The cpu_{suspend}/{resume} implementation provides
such a framework through a kernel interface allowing to save/restore
registers, flush the context to DRAM and suspend/resume to/from
low-power states where processor context may be lost.

The CPU suspend implementation relies on the suspend protocol registered
in CPU operations to carry out a suspend request after context is
saved and flushed to DRAM. The cpu_suspend interface:

int cpu_suspend(unsigned long arg);

allows to pass an opaque parameter that is handed over to the suspend CPU
operations back-end so that it can take action according to the
semantics attached to it. The arg parameter allows suspend to RAM and CPU
idle drivers to communicate to suspend protocol back-ends; it requires
standardization so that the interface can be reused seamlessly across
systems, paving the way for generic drivers.

Context memory is allocated on the stack, whose address is stashed in a
per-cpu variable to keep track of it and passed to core functions that
save/restore the registers required by the architecture.

Even though, upon successful execution, the cpu_suspend function shuts
down the suspending processor, the warm boot resume mechanism, based
on the cpu_resume function, makes the resume path operate as a
cpu_suspend function return, so that cpu_suspend can be treated as a C
function by the caller, which simplifies coding the PM drivers that rely
on the cpu_suspend API.

Upon context save, the minimal amount of memory is flushed to DRAM so
that it can be retrieved when the MMU is off and caches are not searched.

The suspend CPU operation, depending on the required operations (eg CPU vs
Cluster shutdown) is in charge of flushing the cache hierarchy either
implicitly (by calling firmware implementations like PSCI) or explicitly
by executing the required cache maintainance functions.

Debug exceptions are disabled during cpu_{suspend}/{resume} operations
so that debug registers can be saved and restored properly preventing
preemption from debug agents enabled in the kernel.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

Power management software requires the kernel to save and restore
CPU registers while going through suspend and resume operations
triggered by kernel subsystems like CPU idle and suspend to RAM.

This patch implements code that provides save and restore mechanism
for the arm v8 implementation. Memory for the context is passed as
parameter to both cpu_do_suspend and cpu_do_resume functions, and allows
the callers to implement context allocation as they deem fit.

The registers that are saved and restored correspond to the registers set
actually required by the kernel to be up and running which represents a
subset of v8 ISA.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>