All ARMv5 and older CPUs invalidate their caches in the early assembly
setup function, prior to enabling the MMU. This is because the L1
cache should not contain any data relevant to the execution of the
kernel at this point; all data should have been flushed out to memory.
This requirement should also be true for ARMv6 and ARMv7 CPUs - indeed,
these typically do not search their caches when caching is disabled (as
it needs to be when the MMU is disabled) so this change should be safe.
ARMv7 allows there to be CPUs which search their caches while caching is
disabled, and it's permitted that the cache is uninitialised at boot;
for these, the architecture reference manual requires that an
implementation specific code sequence is used immediately after reset
to ensure that the cache is placed into a sane state. Such
functionality is definitely outside the remit of the Linux kernel, and
must be done by the SoC's firmware before _any_ CPU gets to the Linux
kernel.
Changing the data cache clean+invalidate to a mere invalidate allows us
to get rid of a lot of platform specific hacks around this issue for
their secondary CPU bringup paths - some of which were buggy.
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
APMU resources are not common to all R-Car SoCs so don't share this data.
A subsequent patch will correct the CPU cores for the r8a7791.
Signed-off-by: Hisashi Nakamura <hisashi.nakamura.ak@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Patch d6d757c9a4 ("ARM: shmobile: APMU: Add Core-Standby-state for
Suspend to RAM") added both an inline wrapper for shmobile_smp_apmu_suspend_init
and an empty function in arch/arm/mach-shmobile/platsmp-apmu.c. We get a
build failure when both are present, so this patch removes the one in the .c
file and keeps the inline version.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
The function shmobile_smp_apmu_suspend_init() should
be put into the init section to not trigger section
mismatch warnings.
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Adjust the APMU code to allow build when CONFIG_SMP=n.
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
This patch add Core-Standby-state for Suspend to RAM.
Signed-off-by: Keita Kobayashi <keita.kobayashi.ym@renesas.com>
Acked-by: Magnus Damm <damm+renesas@opensource.se>
[horms+renesas@verge.net.au: rebase]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Change location for common.h so it can be used as #include "common.h"
instead of the old style #include <mach/common.h>.
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Use the %pr printk specifier to print resource variables. This fixes
warnings on platforms where resource_size_t has a different size than
int.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Add information to the shared APMU code regarding
the APMU instance used to control the CA7 cores.
This can be used on r8a7790 and r8a73a4, but should
most likely be converted to DT in the future.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Extend the APMU code with a check to only allow boot
of CPU cores that sit in the same cluster as CPU0.
This makes it possible for people to use the r8a790
CA7 boot mode with CA7-cores only. The default CA15
boot mode will enable CA15 cores only. This is an
intentional software limitation to cope with lacking
scheduler support.
By removing this patch it is possible to run all 8 cores
in parallel, but this is not recommended without out of tree
scheduler modfications or custom user space code to control
the CPU affinitiy.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Introduce shared APMU SMP code for mach-shmobile. Both SMP boot up
and CPU Hotplug is supported. This version does not use DT but
if needed this will be added as an incremental feature patch.
The code is designed around CONFIG_NR_CPUS and should in theory support
any number of APMUs, however due to the current DT-less static design
only a single APMU is supported.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
