arm64: Introduce get_cpu_ops() helper function

This introduces get_cpu_ops() to return the CPU operations according to
the given CPU index. For now, it simply returns the @cpu_ops[cpu] as
before. Also, helper function __cpu_try_die() is introduced to be shared
by cpu_die() and ipi_cpu_crash_stop(). So it shouldn't introduce any
functional changes.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>

arm64: Rename cpu_read_ops() to init_cpu_ops()

This renames cpu_read_ops() to init_cpu_ops() as the function is only
called in initialization phase. Also, we will introduce get_cpu_ops() in
the subsequent patches, to retireve the CPU operation by the given CPU
index. The usage of cpu_read_ops() and get_cpu_ops() are difficult to be
distinguished from their names.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: Declare ACPI parking protocol CPU operation if needed

It's obvious we needn't declare the corresponding CPU operation when
CONFIG_ARM64_ACPI_PARKING_PROTOCOL is disabled, even it doesn't cause
any compiling warnings.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arm64: cpu_ops: fix a leaked reference by adding missing of_node_put

The call to of_get_next_child returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
./arch/arm64/kernel/cpu_ops.c:102:1-7: ERROR: missing of_node_put;
acquired a node pointer with refcount incremented on line 69, but
without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yang99@zte.com.cn>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>

arm64: cpu_ops: Add missing 'const' qualifiers

Building the kernel with an LTO-enabled GCC spits out the following "const"
warning for the cpu_ops code:

mm/percpu.c:2168:20: error: pcpu_fc_names causes a section type conflict
with dt_supported_cpu_ops
const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = {
^
arch/arm64/kernel/cpu_ops.c:34:37: note: ‘dt_supported_cpu_ops’ was declared here
static const struct cpu_operations *dt_supported_cpu_ops[] __initconst = {

Fix it by adding missed const qualifiers.

Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arm64: Convert to using %pOF instead of full_name

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Will Deacon <will.deacon@arm.com>

arm64: apply __ro_after_init to some objects

These objects are set during initialization, thereafter are read only.

Previously I only want to mark vdso_pages, vdso_spec, vectors_page and
cpu_ops as __read_mostly from performance point of view. Then inspired
by Kees's patch[1] to apply more __ro_after_init for arm, I think it's
better to mark them as __ro_after_init. What's more, I find some more
objects are also read only after init. So apply __ro_after_init to all
of them.

This patch also removes global vdso_pagelist and tries to clean up
vdso_spec[] assignment code.

[1] http://www.spinics.net/lists/arm-kernel/msg523188.html

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arm64: kernel: implement ACPI parking protocol

The SBBR and ACPI specifications allow ACPI based systems that do not
implement PSCI (eg systems with no EL3) to boot through the ACPI parking
protocol specification[1].

This patch implements the ACPI parking protocol CPU operations, and adds
code that eases parsing the parking protocol data structures to the
ARM64 SMP initializion carried out at the same time as cpus enumeration.

To wake-up the CPUs from the parked state, this patch implements a
wakeup IPI for ARM64 (ie arch_send_wakeup_ipi_mask()) that mirrors the
ARM one, so that a specific IPI is sent for wake-up purpose in order
to distinguish it from other IPI sources.

Given the current ACPI MADT parsing API, the patch implements a glue
layer that helps passing MADT GICC data structure from SMP initialization
code to the parking protocol implementation somewhat overriding the CPU
operations interfaces. This to avoid creating a completely trasparent
DT/ACPI CPU operations layer that would require creating opaque
structure handling for CPUs data (DT represents CPU through DT nodes, ACPI
through static MADT table entries), which seems overkill given that ACPI
on ARM64 mandates only two booting protocols (PSCI and parking protocol),
so there is no need for further protocol additions.

Based on the original work by Mark Salter <msalter@redhat.com>

[1] https://acpica.org/sites/acpica/files/MP%20Startup%20for%20ARM%20platforms.docx

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Loc Ho <lho@apm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Al Stone <ahs3@redhat.com>
[catalin.marinas@arm.com: Added WARN_ONCE(!acpi_parking_protocol_valid() on the IPI]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: force CONFIG_SMP=y and remove redundant #ifdefs

Nobody seems to be producing !SMP systems anymore, so this is just
becoming a source of kernel bugs, particularly if people want to use
coherent DMA with non-shared pages.

This patch forces CONFIG_SMP=y for arm64, removing a modest amount of
code in the process.

Signed-off-by: Will Deacon <will.deacon@arm.com>

ARM64: kernel: unify ACPI and DT cpus initialization

The code that initializes cpus on arm64 is currently split in two
different code paths that carry out DT and ACPI cpus initialization.

Most of the code executing SMP initialization is common and should
be merged to reduce discrepancies between ACPI and DT initialization
and to have code initializing cpus in a single common place in the
kernel.

This patch refactors arm64 SMP cpus initialization code to merge
ACPI and DT boot paths in a common file and to create sanity
checks that can be reused by both boot methods.

Current code assumes PSCI is the only available boot method
when arm64 boots with ACPI; this can be easily extended if/when
the ACPI parking protocol is merged into the kernel.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Mark Rutland <mark.rutland@arm.com> [DT]
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

ARM64: kernel: make cpu_ops hooks DT agnostic

ARM64 CPU operations such as cpu_init and cpu_init_idle take
a struct device_node pointer as a parameter, which corresponds to
the device tree node of the logical cpu on which the operation
has to be applied.

With the advent of ACPI on arm64, where MADT static table entries
are used to initialize cpus, the device tree node parameter
in cpu_ops hooks become useless when booting with ACPI, since
in that case cpu device tree nodes are not present and can not be
used for cpu initialization.

The current cpu_init hook requires a struct device_node pointer
parameter because it is called while parsing the device tree to
initialize CPUs, when the cpu_logical_map (that is used to match
a cpu node reg property to a device tree node) for a given logical
cpu id is not set up yet. This means that the cpu_init hook cannot
rely on the of_get_cpu_node function to retrieve the device tree
node corresponding to the logical cpu id passed in as parameter,
so the cpu device tree node must be passed in as a parameter to fix
this catch-22 dependency cycle.

This patch reshuffles the cpu_logical_map initialization code so
that the cpu_init cpu_ops hook can safely use the of_get_cpu_node
function to retrieve the cpu device tree node, removing the need for
the device tree node pointer parameter.

In the process, the patch removes device tree node parameters
from all cpu_ops hooks, in preparation for SMP DT/ACPI cpus
initialization consolidation.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Tested-by: Mark Rutland <mark.rutland@arm.com> [DT]
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

ARM64 / ACPI: Parse MADT for SMP initialization

MADT contains the information for MPIDR which is essential for
SMP initialization, parse the GIC cpu interface structures to
get the MPIDR value and map it to cpu_logical_map(), and add
enabled cpu with valid MPIDR into cpu_possible_map.

ACPI 5.1 only has two explicit methods to boot up SMP, PSCI and
Parking protocol, but the Parking protocol is only specified for
ARMv7 now, so make PSCI as the only way for the SMP boot protocol
before some updates for the ACPI spec or the Parking protocol spec.

Parking protocol patches for SMP boot will be sent to upstream when
the new version of Parking protocol is ready.

CC: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
CC: Mark Rutland <mark.rutland@arm.com>
Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: Yijing Wang <wangyijing@huawei.com>
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: Jon Masters <jcm@redhat.com>
Tested-by: Timur Tabi <timur@codeaurora.org>
Tested-by: Robert Richter <rrichter@cavium.com>
Acked-by: Robert Richter <rrichter@cavium.com>
Acked-by: Olof Johansson <olof@lixom.net>
Reviewed-by: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arm64: kernel: enable PSCI cpu operations on UP systems

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: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: Slightly improve the warning on CPU0 enable-method

Commit e8765b265a69 (arm64: read enable-method for CPU0) introduced
checks for the enable method on CPU0 (to be later used with CPU
suspend). However, if the kernel is compiled for UP and a DT file is
used with a method like 'spin-table', Linux complains about 'invalid
enable method'. This patch turns it into an 'unsupported enable method'
warning.

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

ARM64: simplify cpu_read_bootcpu_ops using OF/DT helper

Once the cpu_logical_map for any logical cpu is populated with the
corresponding physical identifier(i.e. mpidr), it's device node can
be retrieved using the DT helper 'of_get_cpu_node'. Currently the
device tree parsing code to get boot cpu node is duplicated in
'cpu_read_bootcpu_ops'.

This patch replaces the code parsing the device tree for the boot
cpu with of_get_cpu_node.

Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: read enable-method for CPU0

With the advent of CPU_HOTPLUG, the enable-method property for CPU0 may
tells us something useful (i.e. how to hotplug it back on), so we must
read it along with all the enable-method for all the other CPUs. Even
on UP the enable-method may tell us useful information (e.g. if a core
has some mechanism that might be usable for cpuidle), so we should
always read it.

This patch factors out the reading of the enable method, and ensures
that CPU0's enable method is read regardless of whether the kernel is
built with SMP support.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arm64: reorganise smp_enable_ops

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: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>