[PATCH v2 0/8] dma-buf: heaps: Add secure heap

Yong Wu
2023-11-11T11:16:35Z

This patchset adds three secure heaps:
1) secure_mtk_cm: secure chunk memory for MediaTek SVP (Secure Video Path).
The buffer is reserved for the secure world after bootup and it is used
for vcodec's ES/working buffer;
2) secure_mtk_cma: secure CMA memory for MediaTek SVP. This buffer is
dynamically reserved for the secure world and will be got when we start
playing secure videos, Once the security video playing is complete, the
CMA will be released. This heap is used for the vcodec's frame buffer.
3) secure_cma: Use the kerne CMA ops as the allocation ops.
currently it is a draft version for Vijay and Jaskaran.

For the first two MediaTek heaps will be used v4l2[1] and drm[2], thus we
cannot put it in v4l2 or drm, and create a common heap for them. Meanwhile
We have a limited number of hardware entries to protect memory, we cannot
protect memory arbitrarily, thus the secure memory management is actually
inside OPTEE. The kernel just tells the TEE what size I want and the TEE
will return a "secure handle".

[1] https://lore.kernel.org/linux-mediatek/20231106120423.23364-1-yunfei.dong@mediatek.com/
[2] https://lore.kernel.org/linux-mediatek/20231023044549.21412-1-jason-jh.lin@mediatek.com/

Change note:
v2: 1) Move John's patches into the vcodec patchset since they use the new
dma heap interface directly.
https://lore.kernel.org/linux-mediatek/20231106120423.23364-1-yunfei.dong@mediatek.com/
2) Reword the dt-binding description.
3) Rename the heap name from mtk_svp to secure_mtk_cm.
This means the current vcodec/DRM upstream code doesn't match this.
4) Add a normal CMA heap. currently it should be a draft version.
5) Regarding the UUID, I still use hard code, but put it in a private
data which allow the others could set their own UUID. What's more, UUID
is necessary for the session with TEE. If we don't have it, we can't
communicate with the TEE, including the get_uuid interface, which tries
to make uuid more generic, not working. If there is other way to make
UUID more general, please free to tell me.

v1: https://lore.kernel.org/linux-mediatek/20230911023038.30649-1-yong.wu@mediatek.com/
Base on v6.6-rc1.

Yong Wu (8):
dma-buf: heaps: Initialize a secure heap
dma-buf: heaps: secure_heap: Add private heap ops
dma-buf: heaps: secure_heap: Initialize tee session
dma-buf: heaps: secure_heap: Add tee memory service call
dma-buf: heaps: secure_heap: Add dma_ops
dt-bindings: reserved-memory: Add secure CMA reserved memory range
dma_buf: heaps: secure_heap: Add a new MediaTek CMA heap
dma-buf: heaps: secure_heap: Add normal CMA heap

.../reserved-memory/secure_cma_region.yaml | 44 ++
drivers/dma-buf/heaps/Kconfig | 7 +
drivers/dma-buf/heaps/Makefile | 1 +
drivers/dma-buf/heaps/secure_heap.c | 602 ++++++++++++++++++
4 files changed, 654 insertions(+)
create mode 100644 Documentation/devicetree/bindings/reserved-memory/secure_cma_region.yaml
create mode 100644 drivers/dma-buf/heaps/secure_heap.c

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2.25.1