[PATCH v4 00/10] dma-buf: heaps: Add support for Tegra VPR

[Thierry Reding]

This series adds support for the video protection region (VPR) used on
Tegra SoC devices. It's a special region of memory that is protected
from accesses by the CPU and used to store DRM protected content (both
decrypted stream data as well as decoded video frames).

Patches 1 through 3 add DT binding documentation for the VPR and add the
VPR to the list of memory-region items for display, host1x and NVDEC.

Patch 4 adds bitmap_allocate(), which is like bitmap_allocate_region()
but works on sizes that are not a power of two.

Patch 5 introduces new APIs needed by the Tegra VPR implementation that
allow CMA areas to be dynamically created at runtime rather than using
the fixed, system-wide list. This is used in this driver specifically
because it can use an arbitrary number of these areas (though they are
currently limited to 4).

Patch 6 adds some infrastructure for DMA heap implementations to provide
information through debugfs.

The Tegra VPR implementation is added in patch 7. See its commit message
for more details about the specifics of this implementation.

Finally, patches 8-10 add the VPR placeholder node on Tegra234 and
Tegra264 and hook it up to the host1x node so that it can make use of
this region.

Changes in v4:
- Link to v3: https://patch.msgid.link/20260701-tegra-vpr-v3-0-d80f7b871bb4@xxxxxxxxxx
- fully remove from linear map while chunks are active
- address checkpatch.pl and Sashiko comments
- improve error handling
- remove freezer support

Changes in v3:
- Link to v2: https://patch.msgid.link/20260122161009.3865888-1-thierry.reding@xxxxxxxxxx
- introduce set_memory_device() and set_memory_normal()
- rename VPR nodes to "protected"
- add Tegra264 placeholder nodes

Changes in v2:
- Link to v1: https://patch.msgid.link/20250902154630.4032984-1-thierry.reding@xxxxxxxxx
- Tegra VPR implementation is now more optimized to reduce the number of
  (very slow) resize operations, and allows cross-chunk allocations
- dynamic CMA areas are now trackd separately from static ones, but the
  global number of CMA pages accounts for all areas

Thierry

Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
Thierry Reding (10):
      dt-bindings: reserved-memory: Document Tegra VPR
      dt-bindings: display: tegra: Document memory regions
      dt-bindings: gpu: host1x: Document memory-regions for NVDEC
      bitmap: Add bitmap_allocate() function
      mm/cma: Allow dynamically creating CMA areas
      dma-buf: heaps: Add debugfs support
      dma-buf: heaps: Add support for Tegra VPR
      arm64: tegra: Add VPR placeholder node on Tegra234
      arm64: tegra: Hook up VPR to host1x
      arm64: tegra: Add VPR placeholder node on Tegra264

 .../display/tegra/nvidia,tegra124-vic.yaml         |    8 +
 .../bindings/display/tegra/nvidia,tegra186-dc.yaml |   10 +
 .../bindings/display/tegra/nvidia,tegra20-dc.yaml  |   10 +-
 .../display/tegra/nvidia,tegra20-host1x.yaml       |    7 +
 .../bindings/gpu/host1x/nvidia,tegra234-nvdec.yaml |    8 +
 .../nvidia,tegra-video-protection-region.yaml      |   75 ++
 arch/arm/mm/dma-mapping.c                          |    2 +-
 arch/arm64/boot/dts/nvidia/tegra234.dtsi           |   45 +
 arch/arm64/boot/dts/nvidia/tegra264.dtsi           |   33 +
 arch/s390/mm/init.c                                |    2 +-
 drivers/dma-buf/dma-heap.c                         |   56 +
 drivers/dma-buf/heaps/Kconfig                      |   12 +
 drivers/dma-buf/heaps/Makefile                     |    1 +
 drivers/dma-buf/heaps/tegra-vpr.c                  | 1368 ++++++++++++++++++++
 include/linux/bitmap.h                             |   25 +-
 include/linux/cma.h                                |    8 +-
 include/linux/dma-heap.h                           |    2 +
 include/trace/events/tegra_vpr.h                   |   57 +
 kernel/dma/contiguous.c                            |    2 +-
 mm/cma.c                                           |  221 +++-
 mm/cma.h                                           |    5 +-
 mm/cma_debug.c                                     |    6 +-
 mm/cma_sysfs.c                                     |    6 +-
 mm/mm_init.c                                       |    4 +-
 24 files changed, 1912 insertions(+), 61 deletions(-)
---
base-commit: a6cebf4799ccfd3ea08e45abe5360414fd3822e1
change-id: 20260507-tegra-vpr-cd4bc2509c4c

Best regards,
--  
Thierry Reding <treding@xxxxxxxxxx>