diff options
| author | Claire Chang <tientzu@chromium.org> | 2021-06-19 11:40:41 +0800 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad@kernel.org> | 2021-07-13 20:04:50 -0400 |
| commit | 0b84e4f8b793eb4045fd64f6f514165a7974cd16 (patch) | |
| tree | 321b1f2c11eb5088fb8df9d9033fd37abb9cad41 /kernel/dma/Kconfig | |
| parent | f4111e39a52aa5d5136d890bbd1aa87c1c8fe3bc (diff) | |
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 <tientzu@chromium.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Will Deacon <will@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'kernel/dma/Kconfig')
| -rw-r--r-- | kernel/dma/Kconfig | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 77b405508743..3e961dc39634 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -80,6 +80,20 @@ config SWIOTLB bool select NEED_DMA_MAP_STATE +config DMA_RESTRICTED_POOL + bool "DMA Restricted Pool" + depends on OF && OF_RESERVED_MEM + select SWIOTLB + help + This enables support for restricted DMA pools which provide a level of + DMA memory protection on systems with limited hardware protection + capabilities, such as those lacking an IOMMU. + + For more information see + <Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt> + and <kernel/dma/swiotlb.c>. + If unsure, say "n". + # # Should be selected if we can mmap non-coherent mappings to userspace. # The only thing that is really required is a way to set an uncached bit |