[RFC,0/5] vfio: platform: reset: Introduce tegra234 mgbe reset module

Message

Eric Auger Aug. 29, 2024, 4:11 p.m. UTC

We introduce a new vfio platform reset module for the tegra234
Multi-Gigabit Ethernet (MGBE).

This reset driver is more complex than previous ones because some
resources need to be prepared and released (clocks and reset). The
existing infrastructure was too simplistic to do that. So this series
extends the original single reset function to an ops struct enhanced
with optional open/close callbacks.

There the reset and clocks are handled. the functions are
called on open_device/close_device callback. That's questionable
whether this should be called in init/release instead but memory
regions cannot be ioremapped at that time since
vfio_platform_regions_init is called on .opendevice.

The actual reset toggles the mac reset, disable mac interrupts,
stop DMA requests and do a SW reset.

The reset code is inspired of the native driver:
net/ethernet/stmicro/stmmac/dwxgmac2_dma.c and
net/ethernet/stmicro/stmmac/dwmac-tegra.c

This series can be found at:
https://github.com/eauger/linux/tree/tegra234-mgbe-reset-module-rfc

The qemu series to test with can be found at
https://github.com/eauger/qemu/tree/tegra234-mgbe-rfc

Best Regards

Eric


Eric Auger (5):
  vfio_platform: Introduce vfio_platform_get_region helper
  vfio_platform: reset: Prepare for additional reset ops
  vfio_platform: reset: Introduce new open and close callbacks
  vfio-platform: Add a new handle to store reset data
  vfio/platform: Add tegra234-mgbe vfio platform reset module

 drivers/vfio/platform/reset/Kconfig           |   7 +
 drivers/vfio/platform/reset/Makefile          |   2 +
 .../platform/reset/vfio_platform_amdxgbe.c    |   7 +-
 .../reset/vfio_platform_calxedaxgmac.c        |   7 +-
 .../reset/vfio_platform_tegra234_mgbe.c       | 245 ++++++++++++++++++
 drivers/vfio/platform/vfio_platform_common.c  |  78 ++++--
 drivers/vfio/platform/vfio_platform_private.h |  43 ++-
 7 files changed, 358 insertions(+), 31 deletions(-)
 create mode 100644 drivers/vfio/platform/reset/vfio_platform_tegra234_mgbe.c