Re: [Xen-devel] Compatible string for psci node: v1.0?

[Julien Grall <julien.grall@xxxxxxx>]

On 01/02/18 19:00, Mirela Simonovic wrote:
> Hi,
Hi Mirela,

> I'm working on switching to PSCI v1.0 in Xen (needed to support suspend  > to 
> RAM).
I am about to send a series to add support for PSCI 1.1 (I need it for 
the spectre mitigation). I can send you a temporary branch if you want 
to see whether I missed anything.
> In addition to updates in PSCI implementation, we assumed that 
> compatible property in psci device tree node should be extended with 
> "arm,psci-1.0" (not a must since this doesn't affect Dom0's 
> functionality today, but I would add it if possible).
> Could you please let me know how to add "arm,psci-1.0" to compatible 
> property?
> I assumed that in domain_build.c in make_psci_node() function I need to 
> add "arm,psci-1.0""\0" at the beginning of 'compat' string (although I 
> don't understand the "\0"). That doesn't seem to work. Only 
> "arm,psci-1.0" ends up in compatible property and we need strings for 
> older versions as well.
> I also noticed that even "arm,psci" doesn't appear to be added into the 
> compatible property (without any code modifications from my side). I 
> checked what is generated by debugging and by 'cat' on 
> /sys/firmware/devicetree/base/psci/compatible from Dom0's console.
From the DT specification, each compatible string should be separated 
by '\0'. Doing a hexdump -C in the hardware domain I can see that both 
arm,psci and arm,psci-0.2 are present on latest Xen. So I am not sure 
why it would not be present on your side.
BTW, if you use printk, only the first compatible will be printed 
(printk stop at the '\0').
Cheers,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel