[PATCH v4 05/14] swiotlb: Add DMA_RESTRICTED_POOL

[Claire Chang <tientzu@xxxxxxxxxxxx>]

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

Signed-off-by: Claire Chang <tientzu@xxxxxxxxxxxx>
---
 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