[PATCH 0/5] iommu: apple-dart: Support locked DARTs

[Alyssa Rosenzweig]

Some DARTs on Apple SoCs are "locked" at boot time, meaning we cannot
write most of their configuration registers. Currently, we refuse to
probe locked DARTs and do not include any in the upstream device trees.
However, the DARTs used for the display controller are locked, so we
need to handle locked DARTs as a prerequisite for a KMS driver.

This series teaches the iommu/apple-dart driver about locked DARTs,
preparing for a future upstream display driver. It has been extensively
tested downstream with our work-in-progress display driver.

Signed-off-by: Alyssa Rosenzweig <alyssa at rosenzweig.io>
---
Alyssa Rosenzweig (5):
      iommu/dart: Track if the DART is locked
      iommu/dart: Skip reset for locked DARTs
      iommu/dart: Set DMA domain for locked DARTs
      iommu/dart: Reject identity domain for locked DARTs
      iommu/dart: Assert !locked when configuring

 drivers/iommu/apple-dart.c | 47 +++++++++++++++++++++++++++++++---------------
 1 file changed, 32 insertions(+), 15 deletions(-)
---
base-commit: 2014c95afecee3e76ca4a56956a936e23283f05b
change-id: 20250210-locked-dart-d7ece05f19a8

Best regards,
-- 
Alyssa Rosenzweig <alyssa at rosenzweig.io>