[PATCH 0/7] drm/tyr: add userspace MMIO mmap support

[Deborah Brouwer <deborah.brouwer@collabora.com>]

This series adds support for Panthor-style userspace MMIO mappings to
the Tyr driver.

Panthor reserves a special DRM mmap offset range for exposing selected GPU
MMIO pages directly to userspace. This series implements the initial
userspace-MMIO mmap path for Tyr and wires up support for mapping the
LATEST_FLUSH USER register page.

The mapped page is read-only, non-cached, shared, and faulted in lazily
through a custom VMA fault handler using vmf_insert_pfn_prot(). This
allows userspace to observe GPU cache flush completion directly through
the mapped register instead of polling through an ioctl.

To support this, the series adds a small set of Rust MM and DRM helper
APIs:

* pgprot_noncached() wrapper for Rust MMIO mappings
* VmaRef::pgoff()
* drm::File::device()
* driver-overridable DRM file operations

The series also adds USER register page definitions and stores the MMIO
physical base address in TyrDrmDeviceData so PFNs can be derived during
fault handling.

Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>

---
Daniel Almeida (2):
      mm: rust: add pgprot_noncached helper
      mm: rust: add VMA page offset helper

Deborah Brouwer (5):
      drm/rust: add File::device() helper
      drm/rust: allow drivers to override file operations
      drm/tyr: add USER register page definitions
      drm/tyr: store MMIO physical base address
      drm/tyr: add userspace MMIO mmap support

 drivers/gpu/drm/tyr/driver.rs |  12 +-
 drivers/gpu/drm/tyr/mmap.rs   | 247 ++++++++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/tyr/regs.rs   |  18 +++
 drivers/gpu/drm/tyr/tyr.rs    |   1 +
 rust/helpers/mm.c             |   5 +
 rust/kernel/drm/device.rs     |   4 +-
 rust/kernel/drm/driver.rs     |   6 +
 rust/kernel/drm/file.rs       |  12 ++
 rust/kernel/drm/gem/mod.rs    |   3 +-
 rust/kernel/mm/virt.rs        |  10 ++
 10 files changed, 314 insertions(+), 4 deletions(-)
---
base-commit: 37f748ed0c19e007e7c5677f5d605d6b93841792
change-id: 20260507-tyr-mmap-3a9414046fbb

Best regards,
-- 
Deborah Brouwer <deborah.brouwer@collabora.com>