[PATCH v5 0/5] Device tree support for Hyper-V VMBus driver

Saurabh Sengar
2023-02-09T12:16:50Z

This set of patches expands the VMBus driver to include device tree
support. This feature allows for a kernel boot without the use of ACPI
tables, resulting in a smaller memory footprint and potentially faster
boot times. This is tested by enabling CONFIG_FLAT and OF_EARLY_FLATTREE
for x86.

The first two patches enable compilation of Hyper-V APIs in a non-ACPI
build.

The third patch converts the VMBus driver from acpi to more generic
platform driver.

Further to add device tree documentation for VMBus, it needs to club with
other virtualization driver's documentation. For this rename the virtio
folder to more generic hypervisor, so that all the hypervisor based
devices can co-exist in a single place in device tree documentation. The
fourth patch does this renaming.

The fifth patch introduces the device tree documentation for VMBus.

The sixth patch adds device tree support to the VMBus driver. Currently
this is tested only for x86 and it may not work for other archs.

[V5]
- Removed #else for device tree parsing code. This should help better
test coverage.
- Fix macro '__maybe_unused' warning
- Added below options in Kconfig to enable device tree options for HYPERV
select OF if !ACPI
select OF_EARLY_FLATTREE if !ACPI
- moved dt documantation to bus folder
- update the dt node to have 'bus' as parent node instead of 'soc'. Also
added compatible and ranges property for parent node.
- Made sure dt_binding_check have no error/varnings for microsoft,vmbus.yaml file
- Fix commit messages and add Reviwed-by from Michael for first 3 patches

[V4]
- rebased which fixed return type of 'vmbus_mmio_remove' from int to void
- used __maybe_unused for 'vmbus_of_match' and safeguard vmbus_acpi_device_ids
under #ifdef

[V3]
- Changed the logic to use generic api (for_each_of_range) for parsing "ranges".
- Remove dependency of ACPI for HYPERV in case of x86.
- Removed "device tree bindings" from title and patch subject.
- Removed duplicate vendor prefix, used microsoft instead of msft.
- Use 'soc' in example of device tree documantation for parent node.
- Fixed compatible schemas error generated in other modules referring to
virtio.
- Drop hex notation and leading zeros from device tree cell properties.

Saurabh Sengar (5):
drivers/clocksource/hyper-v: non ACPI support in hyperv clock
Drivers: hv: allow non ACPI compilation for
hv_is_hibernation_supported
Drivers: hv: vmbus: Convert acpi_device to more generic
platform_device
dt-bindings: hypervisor: VMBus
Driver: VMBus: Add device tree support

.../bindings/bus/microsoft,vmbus.yaml | 50 ++++++++
MAINTAINERS | 1 +
drivers/clocksource/hyperv_timer.c | 15 ++-
drivers/hv/Kconfig | 6 +-
drivers/hv/hv_common.c | 4 +
drivers/hv/vmbus_drv.c | 118 ++++++++++++++----
6 files changed, 165 insertions(+), 29 deletions(-)
create mode 100644 Documentation/devicetree/bindings/bus/microsoft,vmbus.yaml

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2.34.1