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>