Hi Furquan,

Thanks for pointing. I`ve missed this patch series.
Yeah omitting the `device lapic` line from the devicetree and adding this patch looks like correct (common) way to handle this issue.

BR,
Mariusz

> > have you tried omitting the `device lapic` line from the devicetree?
>
> I have tested this, in this case Linux shows only one processor core. Therefore the 'device lapic' line is really needed...

Can you please try dropping `device lapic` from the devicetree along with this patch:

diff --git a/src/soc/intel/denverton_ns/cpu.c b/src/soc/intel/denverton_ns/cpu.c
index 1dc0830d86..ecefd3a987 100644
--- a/src/soc/intel/denverton_ns/cpu.c
+++ b/src/soc/intel/denverton_ns/cpu.c
@@ -287,6 +287,9 @@ static const struct mp_ops mp_ops = {

 void denverton_init_cpus(struct device *dev)  {
+       if (!dev->link_list)
+               add_more_links(dev, 1);
+
        /* Clear for take-off */
        if (mp_init_with_smm(dev->link_list, &mp_ops) < 0)
                printk(BIOS_ERR, "MP initialization failure.\n");

I think once you drop the device from device tree, dev->link_list would be NULL and so MP initialization failed for you. This problem is not really unique to denverton and was fixed just a few days back for other Intel SoCs using common/block/cpu/mp_init too:

https://review.coreboot.org/c/coreboot/+/56758
https://review.coreboot.org/c/coreboot/+/56852


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