swiotlb: Add restricted DMA pool initialization

Add the initialization function to create restricted DMA pools from
matching reserved-memory nodes.

Regardless of swiotlb setting, the restricted DMA pool is preferred if
available.

The restricted DMA pools provide a basic level of protection against the
DMA overwriting buffer contents at unexpected times. However, to protect
against general data leakage and system memory corruption, the system
needs to provide a way to lock down the memory access, e.g., MPU.

Signed-off-by: Claire Chang <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Tested-by: Stefano Stabellini <[email protected]>
Tested-by: Will Deacon <[email protected]>
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>

0 files changed, 0 insertions, 0 deletions