[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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

Hi Julien,

Thanks, it looks like the issue was with the way I verified this - cat on /sys/firmware/devicetree/base/psci/compatible from dom0's console returns only the first compatible string set by Xen no matter what.
I have verified by debugging that linux finds the right compatible string in psci_dt_init().


On Thu, Feb 1, 2018 at 8:12 PM, Julien Grall <julien.grall@xxxxxxx> wrote:
On 01/02/18 19:00, Mirela Simonovic wrote:

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').


Julien Grall

Xen-devel mailing list



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.