Re: [PATCH v9 7/7] x86/hygon: Add Family 0x18 SMN access

[Yazen Ghannam]

On Thu, Oct 29, 2026 at 01:33:13PM +0800, Lin Wang wrote:
> All DF nodes in a Hygon socket share one SMN ingress, so SMN accesses
> for a node have to go through a root of the node's socket rather than a
> root per node.
> 
> After DF enumeration, map each DF node to the first root of its socket.
> The roots do not expose their socket IDs, so group them by socket in
> PCI enumeration order. Each DF node holds its own reference to its
> socket's root. Keep config space reserved on all roots for the lifetime
> of the node layer and free the temporary root table after setup.
> 
> Serialize each index/data transaction. A setup failure releases all
> acquired resources without invalidating the DF node cache.
> 
> Hygon drivers such as EDAC need SMN access. Keep the SMN read and write
> helpers local to hygon_node.c until such drivers are added.
> 
> Signed-off-by: Lin Wang <wanglin@xxxxxxxxxxxxxx>

Reviewed-by: Yazen Ghannam <yazen.ghannam@xxxxxxx>

Thanks,
Yazen