[PATCH 0/3] xen/arm: add i.MX8M platform and UART support

[Wig Cheng <onlywig@xxxxxxxxx>]

This series adds Xen support for the NXP i.MX8M family (i.MX8MP / MQ /
MM / MN).  It provides the console UART driver, its early printk, and
the platform glue (SiP SMC whitelist for the calls the dom0 kernel
issues to TF-A).

Tested on i.MX8MP (4x Cortex-A53, GICv3): dom0 boots to login on the
hypervisor console, and a domU starts with a PV disk and virtio
devices running a full Wayland distro.  This addresses the concern
raised on the 2019 i.MX8MQ RFC that only a ramfs dom0 had been shown.

Notes for reviewers:

- Unlike i.MX8MQ, the i.MX8MP device tree uses the GIC as the root
  interrupt controller (interrupt-parent = <&gic>), so no device-tree
  workaround is needed and power domains keep working.

- The i.MX8M family has no SMMU, so device passthrough relies on the
  1:1 direct-mapped hardware domain.

- The SiP SMC whitelist forwards only the function IDs the dom0 kernel
  actually issues (extracted from the upstream and vendor kernels);
  no call outside the whitelist was observed at runtime.


Wig Cheng (3):
  xen/char: add classic i.MX UART driver
  xen/arm64: add early printk for the classic i.MX UART
  xen/arm: add i.MX8M platform support

 xen/arch/arm/Kconfig.debug            |  12 ++
 xen/arch/arm/arm64/debug-imx-uart.inc |  39 +++++
 xen/arch/arm/include/asm/imx-uart.h   |  62 +++++++
 xen/arch/arm/platforms/Makefile       |   1 +
 xen/arch/arm/platforms/imx8m.c        | 116 +++++++++++++
 xen/drivers/char/Kconfig              |   8 +
 xen/drivers/char/Makefile             |   1 +
 xen/drivers/char/imx-uart.c           | 227 ++++++++++++++++++++++++++
 8 files changed, 466 insertions(+)
 create mode 100644 xen/arch/arm/arm64/debug-imx-uart.inc
 create mode 100644 xen/arch/arm/include/asm/imx-uart.h
 create mode 100644 xen/arch/arm/platforms/imx8m.c
 create mode 100644 xen/drivers/char/imx-uart.c

-- 
2.43.0