RFC: ARM && restricted DMA apparently not working

[Jim Quinlan]

We've just started using the resticted memory feature (DMA_RESTRICTED_POOL)
which isolates a region for DMA memory for a particular device,
SWIOTLB-style.  This feature works with ARCH=arm64 but does not work on
ARCH=arm unless I apply the commit to select DMA_DIRECT_REMAP.  This seems
to hold from 5.15 to the present.

I've noticed that arm64 selects DMA_DIRECT_REMAP and arm does not and I'm
guessing that there may be a reason for this?

Regards,
Jim Quinlan
Broadcom STB/CM

Jim Quinlan (1):
  ARM: Select DMA_DIRECT_REMAP to fix restricted memory

 arch/arm/Kconfig | 1 +
 1 file changed, 1 insertion(+)


base-commit: 6465e260f48790807eef06b583b38ca9789b6072
-- 
2.17.1

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