Re: Keystone Issue

[Marc Zyngier <maz@kernel.org>]

On 2020-06-15 20:14, CodeWiz2280 wrote:

[...]

> Also, the latest linux kernel still has the X-Gene storm distributor
> address as "0x78010000" in the device tree, which is what the Xen code
> considers a match with the old firmware.  What were the addresses for
> the device tree supposed to be changed to?

We usually don't care, as the GIC address is provided by the bootloader, 
whether via DT or ACPI (this is certainly what happens on Mustang). 
Whatever is still in the kernel tree is just as dead as the platform it 
describes.

> Is my understanding
> correct that there is a different base address required to access the
> "non-secure" region instead of the "secure" 0x78010000 region?  I'm
> trying to see if there are corresponding different addresses for the
> keystone K2E, but haven't found them yet in the manuals.

There is no such address. Think of the NS bit as an *address space* 
identifier.

The only reason XGene presents the NS part of the GIC at a different 
address is because XGene is broken enough not to have EL3, hence no 
secure mode. To wire the GIC (and other standard ARM IPs) to the core, 
the designers simply used the CPU NS signal as an address bit.

On your platform, the NS bit does exist. I strongly suppose that it 
isn't wired to the GIC. Please talk to your SoC vendor for whether iot 
is possible to work around this.

         M.
-- 
Jazz is not dead. It just smells funny...