[PATCH v4 05/14] swiotlb: Add DMA_RESTRICTED_POOL

Claire Chang
2021-02-09T06:26:17Z

Add a new kconfig symbol, DMA_RESTRICTED_POOL, for restricted DMA pool.

Signed-off-by: Claire Chang <tientzu@chromium.org>
---
kernel/dma/Kconfig | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 479fc145acfc..97ff9f8dd3c8 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -83,6 +83,20 @@ 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
--
2.30.0.478.g8a0d178c01-goog