There are two flags: PSCI_COMPLIANT and PSCI_USE_HVC. When set,
the former signals to the OS that the firmware is PSCI compliant.
The latter selects the appropriate conduit for PSCI calls by
toggling between Hypervisor Calls (HVC) and Secure Monitor Calls
(SMC).

FADT table contains such information in ACPI 5.1, FADT table was
parsed in ACPI table init and copy to struct acpi_gbl_FADT, so
use the flags in struct acpi_gbl_FADT for PSCI init.

Since ACPI 5.1 doesn't support self defined PSCI function IDs,
which means that only PSCI 0.2+ is supported in ACPI.

CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
Tested-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: NYijing Wang <wangyijing@huawei.com>
Tested-by: NMark Langsdorf <mlangsdo@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>
Tested-by: NTimur Tabi <timur@codeaurora.org>
Tested-by: NRobert Richter <rrichter@cavium.com>
Acked-by: NRobert Richter <rrichter@cavium.com>
Acked-by: NOlof Johansson <olof@lixom.net>
Acked-by: NGrant Likely <grant.likely@linaro.org>
Signed-off-by: NGraeme Gregory <graeme.gregory@linaro.org>
Signed-off-by: NTomasz Nowicki <tomasz.nowicki@linaro.org>
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

An arm64 allmodconfig fails to build with GCC 5 due to __asmeq
assertions in the PSCI firmware calling code firing due to mcount
preambles breaking our assumptions about register allocation of function
arguments:

  /tmp/ccDqJsJ6.s: Assembler messages:
  /tmp/ccDqJsJ6.s:60: Error: .err encountered
  /tmp/ccDqJsJ6.s:61: Error: .err encountered
  /tmp/ccDqJsJ6.s:62: Error: .err encountered
  /tmp/ccDqJsJ6.s:99: Error: .err encountered
  /tmp/ccDqJsJ6.s:100: Error: .err encountered
  /tmp/ccDqJsJ6.s:101: Error: .err encountered

This patch fixes the issue by moving the PSCI calls out-of-line into
their own assembly files, which are safe from the compiler's meddling
fingers.
Reported-by: NAndy Whitcroft <apw@canonical.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

ARM64_CPU_SUSPEND config option was introduced to make code providing
context save/restore selectable only on platforms requiring power
management capabilities.

Currently ARM64_CPU_SUSPEND depends on the PM_SLEEP config option which
in turn is set by the SUSPEND config option.

The introduction of CPU_IDLE for arm64 requires that code configured
by ARM64_CPU_SUSPEND (context save/restore) should be compiled in
in order to enable the CPU idle driver to rely on CPU operations
carrying out context save/restore.

The ARM64_CPUIDLE config option (ARM64 generic idle driver) is therefore
forced to select ARM64_CPU_SUSPEND, even if there may be (ie PM_SLEEP)
failed dependencies, which is not a clean way of handling the kernel
configuration option.

For these reasons, this patch removes the ARM64_CPU_SUSPEND config option
and makes the context save/restore dependent on CPU_PM, which is selected
whenever either SUSPEND or CPU_IDLE are configured, cleaning up dependencies
in the process.

This way, code previously configured through ARM64_CPU_SUSPEND is
compiled in whenever a power management subsystem requires it to be
present in the kernel (SUSPEND || CPU_IDLE), which is the behaviour
expected on ARM64 kernels.

The cpu_suspend and cpu_init_idle CPU operations are added only if
CPU_IDLE is selected, since they are CPU_IDLE specific methods and
should be grouped and defined accordingly.

PSCI CPU operations are updated to reflect the introduced changes.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Fix build failure of defconfig when PM_SLEEP is disabled (e.g. by
disabling SUSPEND) and CPU_IDLE enabled:

arch/arm64/kernel/psci.c:543:2: error: unknown field ‘cpu_suspend’ specified in initializer
  .cpu_suspend = cpu_psci_cpu_suspend,
  ^
arch/arm64/kernel/psci.c:543:2: warning: initialization from incompatible pointer type [enabled by default]
arch/arm64/kernel/psci.c:543:2: warning: (near initialization for ‘cpu_psci_ops.cpu_prepare’) [enabled by default]
make[1]: *** [arch/arm64/kernel/psci.o] Error 1

The cpu_operations.cpu_suspend field exists only if ARM64_CPU_SUSPEND is
defined, not CPU_IDLE.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

This fix rectifies the psci cpu_suspend implementation to check the
PSCI power state parameter type field associated with the requested idle
state index.
Acked-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NAmit Daniel Kachhap <amit.daniel@samsung.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

During the 3.18 merge period additional __get_cpu_var uses were
added. The patch converts these to this_cpu_ptr().
Signed-off-by: NChristoph Lameter <cl@linux.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NTejun Heo <tj@kernel.org>

This patch implements the cpu_suspend cpu operations method through
the PSCI CPU SUSPEND API. The PSCI implementation translates the idle state
index passed by the cpu_suspend core call into a valid PSCI state according to
the PSCI states initialized at boot through the cpu_init_idle() CPU
operations hook.

The PSCI CPU suspend operation hook checks if the PSCI state is a
standby state. If it is, it calls the PSCI suspend implementation
straight away, without saving any context. If the state is a power
down state the kernel calls the __cpu_suspend API (that saves the CPU
context) and passed the PSCI suspend finisher as a parameter so that PSCI
can be called by the __cpu_suspend implementation after saving and flushing
the context as last function before power down.

For power down states, entry point is set to cpu_resume physical address,
that represents the default kernel execution address following a CPU reset.
Reviewed-by: NAshwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

PSCI init functions must be marked as __init so that they are freed
by the kernel upon boot.

This patch marks the PSCI init functions as such since they need not
be persistent in the kernel address space after the kernel has booted.
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

PSCI CPU operations have to be enabled on UP kernels so that calls
like eg cpu_suspend can be made functional on UP too.

This patch reworks the PSCI CPU operations so that they can be
enabled on UP systems.
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

PSCIv0.2 adds a new function called AFFINITY_INFO, which
can be used to query if a specified CPU has actually gone
offline. Calling this function via cpu_kill ensures that
a CPU has quiesced after a call to cpu_die. This helps
prevent the CPU from doing arbitrary bad things when data
or instructions are clobbered (as happens with kexec)
in the window between a CPU announcing that it is dead
and said CPU leaving the kernel.
Signed-off-by: NAshwin Chaugule <ashwin.chaugule@linaro.org>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

The PSCIv0.2 spec defines standard values of function IDs
and introduces a few new functions. Detect version of PSCI
and appropriately select the right PSCI functions.
Signed-off-by: NAshwin Chaugule <ashwin.chaugule@linaro.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

psci_init() is written to return err code if something goes wrong. However,
the single user, setup_arch(), doesn't care about it. Moreover, every error
path is supplied with a clear message which is enough for pleasant debugging.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Since 652af899 "arm64: factor out spin-table
boot method" psci prefix's been introduced. We have a common pr_fmt, so clean
them up.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch adds support for using PSCI CPU_OFF calls for CPU hotplug.
With this code it is possible to hot unplug CPUs with "psci" as their
boot-method, as long as there's an appropriate cpu_off function id
specified in the psci node.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The arm64 kernel has an internal holding pen, which is necessary for
some systems where we can't bring CPUs online individually and must hold
multiple CPUs in a safe area until the kernel is able to handle them.
The current SMP infrastructure for arm64 is closely coupled to this
holding pen, and alternative boot methods must launch CPUs into the pen,
where they sit before they are launched into the kernel proper.

With PSCI (and possibly other future boot methods), we can bring CPUs
online individually, and need not perform the secondary_holding_pen
dance. Instead, this patch factors the holding pen management code out
to the spin-table boot method code, as it is the only boot method
requiring the pen.

A new entry point for secondaries, secondary_entry is added for other
boot methods to use, which bypasses the holding pen and its associated
overhead when bringing CPUs online. The smp.pen.text section is also
removed, as the pen can live in head.text without problem.

The cpu_operations structure is extended with two new functions,
cpu_boot and cpu_postboot, for bringing a cpu into the kernel and
performing any post-boot cleanup required by a bootmethod (e.g.
resetting the secondary_holding_pen_release to INVALID_HWID).
Documentation is added for cpu_operations.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

For hotplug support, we're going to want a place to store operations
that do more than bring CPUs online, and it makes sense to group these
with our current smp_enable_ops. For cpuidle support, we'll want to
group additional functions, and we may want them even for UP kernels.

This patch renames smp_enable_ops to the more general cpu_operations,
and pulls the definitions out of smp code such that they can be used in
UP kernels. While we're at it, fix up instances of the cpu parameter to
be an unsigned int, drop the init markings and rename the *_cpu
functions to cpu_* to reduce future churn when cpu_operations is
extended.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The functions in psci.c are only used from smp_psci.c, and smp_psci
cannot function without psci.c. Additionally psci.c is built when !SMP,
where it's expected that cpu_suspend may be useful.

This patch unifies the two files, removing pointless duplication and
paving the way for PSCI support in UP systems.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

This patch adds support for the Power State Coordination Interface
defined by ARM, allowing Linux to request CPU-centric power-management
operations from firmware implementing the PSCI protocol.
Signed-off-by: NWill Deacon <will.deacon@arm.com>
[Marc: s/u32/u64/ in the relevant spots, and switch from an initcall
 to an simpler init function]
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>