[RFC PATCH v4 0/8] add support for CDX bus

Nipun Gupta
2022-10-14T04:41:24Z

This patch series introduces AMD CDX bus, which provides a
mechanism to discover/rescan FPGA devices on run-time. These
devices are memory mapped on system bus for embedded CPUs, and
added as CDX devices in Linux framework.

This RFC:
- Intrduces the CDX bus controller and CDX devices.
- Adds rescan and reset support for the CDX bus.
- Add support for reset for CDX devices.
- Support for CDX bus in arm-smmu-v3 driver
- Support for CDX-MSI domain.

Please NOTE: This RFC change does not support the CDX bus firmware
interface as it is under development, and this series aims to get
an early feedback from the community. Firmware interaction are
stubbed as MCDI APIs which is a protocol used by AMD to interact
with Firmware.

Changes in v2:
- introduce CDX bus infrastructure
- fixed code for making compatible visible for devices
having the 'compatible' property only (Greg K-H)
- moved CDX-MSI domain as part of CDX bus infrastructure.
previously it was part of irqchip (Marc Zynger).
- fixed few prints (Greg K-H)
- support rescan and reset of CDX bus
- add VFIO reset module for CDX bus based devices

Changes in v3:
- Move CDX bus as a new bus type in kernel rather than
using the platform devices (Greg K-H, Marc Zynger)
- Correspondingly update ARM SMMU v3
- Add support for vfio-cdx driver
- Updated device tree yaml with correct binding information
(Krzysztof Kozlowski)
- remove 'compatible' sysfs platform patch which was required
for CDX devices exposed as platform devices

Changes in v4:
- Separate CDX bus and CDX controller driver (Greg K-H)
- Added MSI interfacing to Firmware for writing MSI message
to firmware so it can be provided to the device.
- Fix MSI review comments - multiple cleanups (Mark Zynger)
- Fix the device tree yaml compilation (Rob Herring, Krzysztof)
- removed vfio-cdx from this series. It will be added after bus
support is complete (Jason)

Nipun Gupta (8):
dt-bindings: bus: add CDX bus device tree bindings
bus/cdx: add the cdx bus driver
iommu/arm-smmu-v3: support ops registration for CDX bus
bux/cdx: support dma configuration for CDX devices
bus/cdx: add bus and device attributes
irq/msi: use implicit msi domain for alloc and free
bus/cdx: add cdx-MSI domain with gic-its domain as parent
bus/cdx: add cdx controller

.../devicetree/bindings/bus/xlnx,cdx.yaml | 66 +++
MAINTAINERS | 8 +
drivers/base/platform-msi.c | 4 +-
drivers/bus/Kconfig | 1 +
drivers/bus/Makefile | 3 +
drivers/bus/cdx/Kconfig | 17 +
drivers/bus/cdx/Makefile | 8 +
drivers/bus/cdx/cdx.c | 557 ++++++++++++++++++
drivers/bus/cdx/cdx.h | 76 +++
drivers/bus/cdx/cdx_msi.c | 161 +++++
drivers/bus/cdx/controller/Kconfig | 16 +
drivers/bus/cdx/controller/Makefile | 8 +
drivers/bus/cdx/controller/cdx_controller.c | 210 +++++++
drivers/bus/cdx/controller/mcdi_stubs.c | 68 +++
drivers/bus/cdx/controller/mcdi_stubs.h | 101 ++++
drivers/bus/fsl-mc/fsl-mc-msi.c | 4 +-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 16 +-
drivers/pci/msi/irqdomain.c | 4 +-
drivers/soc/ti/ti_sci_inta_msi.c | 2 +-
include/linux/cdx/cdx_bus.h | 165 ++++++
include/linux/mod_devicetable.h | 13 +
include/linux/msi.h | 10 +-
kernel/irq/msi.c | 22 +-
scripts/mod/devicetable-offsets.c | 4 +
scripts/mod/file2alias.c | 12 +
25 files changed, 1529 insertions(+), 27 deletions(-)
create mode 100644 Documentation/devicetree/bindings/bus/xlnx,cdx.yaml
create mode 100644 drivers/bus/cdx/Kconfig
create mode 100644 drivers/bus/cdx/Makefile
create mode 100644 drivers/bus/cdx/cdx.c
create mode 100644 drivers/bus/cdx/cdx.h
create mode 100644 drivers/bus/cdx/cdx_msi.c
create mode 100644 drivers/bus/cdx/controller/Kconfig
create mode 100644 drivers/bus/cdx/controller/Makefile
create mode 100644 drivers/bus/cdx/controller/cdx_controller.c
create mode 100644 drivers/bus/cdx/controller/mcdi_stubs.c
create mode 100644 drivers/bus/cdx/controller/mcdi_stubs.h
create mode 100644 include/linux/cdx/cdx_bus.h

--
2.25.1