ARM: mm: fix typos in comments

Various spelling mistakes in comments.
Detected with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

ARM: mm: Remove virtual address print from B15 RAC driver

We would be trying to print the kernel virtual address of the base
register address which is not very useful and is not displayed by
default because of pointer restriction. Print the Device Tree node name
instead which is what was originally intended.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

Based on 2 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 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 #

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

ARM: B15: Update to support Brahma-B53

The B53 CPU design supports up to 8 processors, which moved the RAC_FLUSH_REG
offset 0x4 bytes below to make room for a RAC_CONFIG2_REG to control RAC
settings for CPU4-7.

Lookup the processor type (B15 or B53) and adjust the RAC_FLUSH_REG offset
accordingly, if we do not know the processor, bail out.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

ARM: 8741/1: B15: fix unused label warnings

The new conditionally compiled code leaves some labels and one
variable unreferenced when CONFIG_HOTPLUG_CPU and CONFIG_PM_SLEEP
are disabled:

arch/arm/mm/cache-b15-rac.c: In function 'b15_rac_init':
arch/arm/mm/cache-b15-rac.c:353:1: error: label 'out_unmap' defined but not used [-Werror=unused-label]
out_unmap:
^~~~~~~~~
arch/arm/mm/cache-b15-rac.c:351:1: error: label 'out_cpu_dead' defined but not used [-Werror=unused-label]
out_cpu_dead:
^~~~~~~~~~~~
At top level:
arch/arm/mm/cache-b15-rac.c:53:12: error: 'rac_config0_reg' defined but not used [-Werror=unused-variable]

This replaces the existing #ifdef conditionals with IS_ENABLED()
checks that let the compiler figure out for itself which code to
drop.

Fixes: 55de88778f4b ("ARM: 8726/1: B15: Add CPU hotplug awareness")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

ARM: 8728/1: B15: Register reboot notifier for KEXEC

During kexec, we will go through kernel_kexec() -> syscore_suspend() if
CONFIG_KEXEC_JUMP is set, if not, down the road we end-up calling
kernel_restart_prepare() which invokes reboot notifiers with
SYS_RESTART.

We register a reboot notifier to make sure that the B15 read-ahead cache
is disabled, since it is another level of instruction and data cache,
and we want to avoid any potential side effects with booting a new
kernel with such a cache still turned on.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

ARM: 8730/1: B15: Add suspend/resume hooks

The Broadcom Brahma-B15 CPU readahead cache registers will be restored
to their Power-on-Reset values after a S3 suspend/resume cycles, so we
want to restore what we had enabled before.

Another thing we want to take care of is disabling the read-ahead cache
prior to suspending to avoid any sort of side effect with the spinlock
we need to grab to serialize register accesses.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

ARM: 8726/1: B15: Add CPU hotplug awareness

The Broadcom Brahma-B15 readahead cache needs to be disabled,
respectively re-enable during a CPU hotplug. In case we were not to do,
CPU hotplug would occasionally fail with random crashes when a given CPU
exits the coherency domain while the RAC is still enabled, as it would
get stale data from the RAC.

In order to avoid adding any specific B15 readahead-cache awareness to
arch/arm/mach-bcm/hotplug-brcmstb.c we use a CPU hotplug state machine
which allows us to catch CPU hotplug events and disable/flush enable the
RAC accordingly.

Signed-off-by: Alamy Liu <alamyliu@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

ARM: 8725/1: Add Broadcom Brahma-B15 readahead cache support

This patch adds support for the Broadcom Brahma-B15 CPU readahead cache
controller. This cache controller sits between the L2 and the memory bus
and its purpose is to provide a friendler burst size towards the DDR
interface than the native cache line size.

The readahead cache is mostly transparent, except for
flush_kern_cache_all, which is precisely what we are overriding here.

The readahead cache only intercepts reads, and does invalidate on
writes (IOW), as such, some data can remain stale in any of its buffers, such
that we need to flush it, which is an operation that needs to happen in
a particular order:

- disable the readahead cache
- flush it
- call the appropriate cache-v7.S function
- re-enable

This patch tries to minimize the impact to the cache-v7.S file by only
providing a stub in case CONFIG_CACHE_B15_RAC is enabled (default for
ARCH_BRCMSTB since it is the current user).

Signed-off-by: Alamy Liu <alamyliu@broadcom.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>