This is V3 of Emma Mobile EV2 SMP support.
At this point only the most basic form of SMP operation
is supported. TWD and CPU Hotplug support is excluded.
Tied to both the Emma Mobile EV2 and the KZM9D board
due to the need to switch on board in platsmp.c and
the newly introduced need for static mappings.
The static mappings are needed to allow hardware
acces early during boot when SMP is initialized.
This early requirement forces us to also map in
the SMU registers.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add support for the new smp_twd runtime registration interface
to the shmobile platforms, and remove the old compile-time support.
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This patch contains r8a7779 SMP support V3 - now including
CPU hotplug offine and online support. The r8a7779 power
domain code is tied together with SMP glue code which allows
us to control the power domains via CPU hotplug.
At this point the kernel boots with the 4 Cortex-A9 cores in
SMP mode and all CPU cores except CPU0 can be hotplugged.
The code in platsmp.c is quite far from pretty, but it is
kept like that intentionally to avoid creating layers of
code that will go away in the near future anyway. The code
needs to be updated when some per-SoC handling code will be
added to the ARM architecture, see the following patch for
more information:
"[RFC PATCH 0/3] Per SoC descriptor"
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add the function shmobile_platform_kill_cpu() to allow
SoC specific code to tie in their CPU shutdown code.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Rather than clipping the number of CPUs using the compile-time NR_CPUS
constant, use the runtime nr_cpu_ids value instead. This allows the
nr_cpus command line option to work as expected.
Cc: <stable@kernel.org>
Reported-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Kota2 base board support including the on-chip SCIFA2
serial console and the on-board SMSC911X ethernet port.
The s73a0 SMP bits are also updated to include Kota2.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
If an ARM system has multiple cpus in the same socket and the
kernel is booted with maxcpus=1, secondary cpus are possible but
not present due to how platform_smp_prepare_cpus() is called.
Since most typical ARM processors don't actually support physical
hotplug, initialize the present map to be equal to the possible
map in generic ARM SMP code. Also, always call
platform_smp_prepare_cpus() as long as max_cpus is non-zero (0
means no SMP) to allow platform code to do any SMP setup.
After applying this patch it's possible to boot an ARM system
with maxcpus=1 on the command line and then hotplug in secondary
cpus via sysfs. This is more in line with how x86 does things.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than having each platform class provide a mach/smp.h header for
smp_cross_call(), arrange for them to register the function with the
core ARM SMP code instead.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add SMP support for ag5evm and the sh73a0 processor.
Onlining and offlining works well, but at this point
offlined processor cores are not put into sleep mode.
There is no spinlock for syncing the secondary core
with the first one in this implementation. The code
instead relies on the cpu_online() check in __cpu_up().
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Add SMP base support for R-Mobile / SH-Mobile processors.
This patch contains all base code to support CONFIG_SMP
regardless of ARCH_SHMOBILE processor type. Both local timer
and CPU hotplug are supported, but no processor specific
code is included.
At this point only the default behavior is in place, so
a single core will always be used even though CONFIG_SMP
is enabled on multicore systems.
The SMP Kconfig entry for arch/arm/Kconfig is excluded from
this patch to simplify merging.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
