The "powered-down" cpuidle mode of Tegra20 needs the CPU0 be the last one
core to go into this mode before other core. The coupled cpuidle framework
can help to sync the MPCore to coupled state then go into "powered-down"
idle mode together. The driver can just assume the MPCore come into
"powered-down" mode at the same time. No need to take care if the CPU_0
goes into this mode along and only can put it into safe idle mode (WFI).
The powered-down state of Tegra20 requires power gating both CPU cores.
When the secondary CPU requests to enter powered-down state, it saves
its own contexts and then enters WFI for waiting CPU0 in the same state.
When the CPU0 requests powered-down state, it attempts to put the secondary
CPU into reset to prevent it from waking up. Then power down both CPUs
together and power off the cpu rail.
Be aware of that, you may see the legacy power state "LP2" in the code
which is exactly the same meaning of "CPU power down".
Based on the work by:
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
The powered-down state of Tegra20 requires power gating both CPU cores.
When the secondary CPU requests to enter powered-down state, it saves
its own contexts and then enters WFI. The Tegra20 had a limition to
power down both CPU cores. The secondary CPU must waits for CPU0 in
powered-down state too. If the secondary CPU be woken up before CPU0
entering powered-down state, then it needs to restore its CPU states
and waits for next chance.
Be aware of that, you may see the legacy power state "LP2" in the code
which is exactly the same meaning of "CPU power down".
Based on the work by:
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Updating the cache maintenance order before CPU shutdown when doing CPU
hotplug.
The old order:
* clean L1 by flush_cache_all
* exit SMP
* CPU shutdown
Adapt to:
* disable L1 data cache by clear C bit
* clean L1 by v7_flush_dcache_louis
* exit SMP
* CPU shutdown
For CPU hotplug case, it's no need to do "flush_cache_all". And we should
disable L1 data cache before clean L1 data cache. Then leaving the SMP
coherency.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
The L2 RAM is in different power domain from the CPU cluster. So the
L2 content can be retained over CPU suspend/resume. To do that, we
need to disable L2 after the MMU is disabled, and enable L2 before
the MMU is enabled. But the L2 controller is in the same power domain
with the CPU cluster. We need to restore it's settings and re-enable
it after the power be resumed.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
This is a power gating idle mode. It support power gating vdd_cpu rail
after all cpu cores in "powered-down" status. For Tegra30, the CPU0 can
enter this state only when all secondary CPU is offline. We need to take
care and make sure whole secondary CPUs were offline and checking the
CPU power gate status. After that, the CPU0 can go into "powered-down"
state safely. Then shut off the CPU rail.
Be aware of that, you may see the legacy power state "LP2" in the code
which is exactly the same meaning of "CPU power down".
Base on the work by:
Scott Williams <scwilliams@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
This supports power-gated idle on secondary CPUs for Tegra30. The
secondary CPUs can go into powered-down state independently. When
CPU goes into this state, it saves it's contexts and puts itself
to flow controlled WFI state. After that, it will been power gated.
Be aware of that, you may see the legacy power state "LP2" in the
code which is exactly the same meaning of "CPU power down".
Based on the work by:
Scott Williams <scwilliams@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
The CPU suspending on Tegra means CPU power gating. We add a resume
function for taking care the CPUs that resume from power gating status.
This function was been hooked to the reset handler. We take care
everything here before go into kernel.
Be aware of that, you may see the legacy power status "LP2" in the code
which is exactly the same meaning of "CPU power down".
Based on the work by:
Scott Williams <scwilliams@nvidia.com>
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Nothing outside mach-tegra uses this file, so there's no need for it to
be in <mach/>.
Since uncompress.h and debug-macro.S remain in include/mach, they need
to include "../../iomap.h" becaue of this change. uncompress.h will soon
be deleted in later multi-platform/single-zImage patches. debug-macro.S
will need to continue to include this header using an explicit relative
path, to avoid duplicating the physical->virtual address mapping that
iomap.h dictates.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Hotplug function put CPU in offline or online mode at runtime.
When the CPU been put into offline, it was been clock gated. The
offline CPU can be power gated, when the remaining CPU goes into
LP2.
Based on the worked by:
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Hotplug function put CPUs in offline or online state at runtime.
When the CPU been put in the offline state, it was been clock and
power gated. Except primary CPU other CPUs can be hotplugged.
Based on the work by:
Scott Williams <scwilliams@nvidia.com>
Colin Cross <ccross@android.com>
Gary King <gking@nvidia.com>
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
There are some common macros for Tegra low-level assembly code. Clean
up them into one header file and move the definitions that will be
re-used into it as well.
Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
