The SCU connects one to four Cortex-A5/Cortex-A9 processors
to the memory system through the AXI interfaces.
The SCU functions are to:
- maintain data cache coherency between the Cortex-A5/Cortex-A9
processors
- initiate L2 AXI memory accesses
- arbitrate between Cortex-A5/Cortex-A9 processors requesting
L2 accesses
- manage ACP accesses.
Snoop Control Unit will enable to snoop on other CPUs caches.
This is very important when it comes to synchronizing data between
CPUs. As an example, there is a high chance that data might be
cache'd and other CPUs can't see the change. In such cases,
if snoop control unit is enabled, data is synchoronized immediately
between CPUs and the changes are visible to other CPUs.
This driver provides functionality to enable SCU as well as enabling
user to know the following
- number of CPUs present
- is a particular CPU operating in SMP mode or AMP mode
- data cache size of a particular CPU
- does SCU has ACP port
- is L2CPRESENT
Change-Id: I0d977970154fa60df57caf449200d471f02312a0
Signed-off-by: Vishnu Banavath <vishnu.banavath@arm.com>
a5ds only has always-on power domain and there is no power control
present. However, without the pwr_domain_off handler, the kernel
panics when the user will try to switch off secondary cores. The
a5ds_pwr_domain_off handler will prevent kernel from crashing,
i.e. the kernel will attempt but fail to shut down the secondary CPUs
if the user tries to switch them offline.
Change-Id: I3c2239a1b6f035113ddbdda063c8495000cbe30c
Signed-off-by: Usama Arif <usama.arif@arm.com>
Enable cores 1-3 using psci. On receiving the smc call from kernel,
core 0 will bring the secondary cores out pen and signal an event for
the cores. Currently on switching the cores is enabled i.e. it is not
possible to suspend, switch cores off, etc.
Change-Id: I6087e1d2ec650e1d587fd543efc1b08cbb50ae5f
Signed-off-by: Usama Arif <usama.arif@arm.com>
For the secondary CPUs, hold the cpu in wfe rather then panic.
This will be needed when multicore support is added to a5ds as
the smc call will write to the hold base and signal an event to
power on the secondary CPUs.
Change-Id: I0ffc2059e9ef894c21375ca5c94def859bfa6599
Signed-off-by: Usama Arif <usama.arif@arm.com>
The watchdog is configured with a default value of 256 seconds in order
to implement the Trusted Board Boot Requirements.
For the FVP and Juno platforms, the FWU process relies on a watchdog
reset. In order to automate the test of FWU, the length of this process
needs to be as short as possible. Instead of waiting for those 4 minutes
to have a reset by the watchdog, tell it to reset immediately.
There are no side effects as the value of the watchdog's load register
resets to 0xFFFFFFFF.
Tested on Juno.
Change-Id: Ib1aea80ceddc18ff1e0813a5b98dd141ba8a3ff2
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
This patch adds support for Cortex-A5 FVP for the
DesignStart program. DesignStart aims at providing
low cost and fast access to Arm IP.
Currently with this patch only the primary CPU is booted
and the rest of them wait for an interrupt.
Signed-off-by: Usama Arif <usama.arif@arm.com>
Change-Id: I3a2281ce6de2402dda4610a89939ed53aa045fab
Vishnu Banavath
Usama Arif
Ambroise Vincent