iommu/arm-smmu: Fall back to global bypass

Browse source

Unlike SMMUv2, SMMUv3 has no easy way to bypass unknown stream IDs,
other than allocating and filling in the entire stream table with bypass
entries, which for some configurations would waste *gigabytes* of RAM.
Otherwise, all transactions on unknown stream IDs will simply be aborted
with a C_BAD_STREAMID event.

Rather than render the system unusable in the case of an invalid DT,
avoid enabling the SMMU altogether such that everything bypasses
(though letting the explicit disable_bypass option take precedence).

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

...

This commit is contained in:

Robin Murphy 2016-09-12 17:13:44 +01:00 • committed by Will Deacon

parent b9bc881180

commit dc87a98db7

1 changed files with 44 additions and 4 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

48

drivers/iommu/arm-smmu-v3.c

View file