Re: [PATCH v6 1/5] x86/amd_nb: Add support for northbridges on Aldebaran
From: Chatradhi, Naveen Krishna
Date: Tue Nov 09 2021 - 06:30:23 EST
Hi Boris,
On 11/9/2021 12:33 AM, Borislav Petkov wrote:
[CAUTION: External Email]
On Mon, Nov 08, 2021 at 10:23:49PM +0530, Chatradhi, Naveen Krishna wrote:
Northbridges on CPUs and GPUs can be described using the elements in the
above structure.
If you're going to describe *northbridges*, then your struct cannot be called
system_topology...
I thought organizing the data in a structure would simplify the
initialization of cpus and gpus.
Ehh, did you even read my mail where I tried to explain that sprinkling
if (gpu)
this
else
that
all over amd_cache_northbridges() is not proper design?
;-\
I will modify the patch to enumerate gpu northbridge info only if there are
gpu nodes with pci_device to access the node_map registers.
Why would you do that? What's the advantage?
How about you answer my questions first so that we agree on the design
first before you go and do things?
I was trying to handle both cpu and cpu northbridge enumeration in the
amd_cache_northbridges() itself by reusing the existing structures and APIs.
Should have seen this through more clearly. As, this is working well for
the following reasons.
a. Allocating the amd_northbridges.nb after identifying both the cpu and
gpu misc devices, would extend node_to_amd_nb(node) for both cpu and gpu
nodes.
It is used extensively in this module. However, the roots_per_misc
value is different in case of cpus and gpus and that needed to be
handled seperately.
b. amd_nb_num(void) is used by other modules in the kernel, returning
the total count of CPU and GPU northbridges would break the existing code.
I understood your point now.
When we create separate functions for caching cpu and gpu devices, is it
okay to create "struct amd_gpu_nb_info" with the following fields
a. gpu_num;
b. struct amd_northbridge *gpu_nb;
c. gpu_node_start_id;
While, amd_nb_num(), continues to return number of cpu NBs
Add new API amd_gpu_nb_num(), return number of gpu NBs
and modify the node_to_amd_nb(node) to extend the same behavior for gpu
devices also
Regards,
naveenk
Hmm.
--
Regards/Gruss,
Boris.
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