[PATCH v5 00/10] dma-buf: heaps: Add support for Tegra VPR
From: Thierry Reding
Date: Fri Aug 14 2026 - 11:31:43 EST
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 memory to be allocated at a fixed offset within a CMA area. Tegra
VPR needs this in order to implement its own allocator on top of CMA to
meet the strict hardware requirements. This replaces the dynamic CMA
area creation patch from earlier versions.
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 v5:
- use a single CMA area in combination with the new cma_alloc_at() API
- drop dynamic CMA area allocation patch
- various cleanups
- Link to v4: https://patch.msgid.link/20260807-tegra-vpr-v4-0-5510d16af89e@xxxxxxxxxx
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: Introduce cma_alloc_at() API
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/arm64/boot/dts/nvidia/tegra234.dtsi | 45 +
arch/arm64/boot/dts/nvidia/tegra264.dtsi | 33 +
drivers/dma-buf/dma-heap.c | 52 +
drivers/dma-buf/heaps/Kconfig | 12 +
drivers/dma-buf/heaps/Makefile | 1 +
drivers/dma-buf/heaps/tegra-vpr.c | 1410 ++++++++++++++++++++
include/linux/bitmap.h | 25 +-
include/linux/cma.h | 4 +
include/linux/dma-heap.h | 2 +
include/trace/events/cma.h | 63 +
include/trace/events/tegra_vpr.h | 57 +
mm/cma.c | 148 ++
18 files changed, 1964 insertions(+), 6 deletions(-)
---
base-commit: 48ae42ae65bf76d723943c717044a09ba6666e56
change-id: 20260507-tegra-vpr-cd4bc2509c4c
Best regards,
--
Thierry Reding <treding@xxxxxxxxxx>