Hi, Rafael J
This patch wants to put some generic control logic in container, and
these logic can
cover a batch of scenarios similar to ours. ACPI power resources
interface is not confilct
with this patch and can be used inside the container for more
complicated scenarios.
In our secenaio, we need to control the power of some HBM memory device,
each of it
will be configured as a PNP0C80, HBM devices in one socket are in the
same power
domain and need to power on/off together. Every HBM memory device
represent a numa
node and have no cpu on it. The topology in one socket can be simplifed
and represented as
+---------+
| node0 |
| CPUs |
| DRAM |
+---------+
|
+------+-------+
| |
+---------+ +---------+
| node1 | | node2 |
| no-cpu | | no-cpu |
| HBM | | HBM |
+---------+ +---------+
To use ACPI power domain management interface, we need to develop a
specialized
driver to maintain the relationship between socket id and numa nodes to
tell the
userspace which socket does this numa node belong to. Note that the numa
node in
the same socket will be power on/off together.
Socket id of a memory device can be reported by BIOS via DSDT or other
ACPI tables,
but we can just skip this step by put all of the devices belongs to the
same socket
in a container. And, we can call each child devices' "_PXM" function to
expose numa
nodes of HBM devices to userspace.
Besides, To power off the devices we need first to offline these ACPI
devices, and then
call the ACPI function "_EJ0" to finally remove it. This are also
generic logic that can be
used to remove ejectable devices.
what we really need is a place to support these generic control logic,
rather than the
interfaces to implement our requirements.
Best Regards,
Zekun, Zhang
在 2022/10/29 1:07, Rafael J. Wysocki 写道:
On Tue, Oct 25, 2022 at 8:17 AM Zhang Zekun <zhangzekun11@xxxxxxxxxx> wrote:
Platform devices which supports power control are often required to be
power off/on together with the devices in the same power domain. However,
there isn't a generic driver that support the power control logic of
these devices.
Not true.
There is the ACPI power resources interface designed to represent
power domains that is well supported and used in the industry.
If it doesn't work for you, explain why.
