]> git.baikalelectronics.ru Git - kernel.git/commit
iommu/io-pgtable-arm: Support coherency for Mali LPAE
authorRobin Murphy <robin.murphy@arm.com>
Tue, 22 Sep 2020 14:16:48 +0000 (15:16 +0100)
committerNeil Armstrong <narmstrong@baylibre.com>
Fri, 30 Oct 2020 09:08:08 +0000 (10:08 +0100)
commitb3880b955190fbf211fbd3f1c4d576a6ab297c67
treeda46f73386480cbb537fcfedcab4e229a902ce51
parentc533fbc4f583c31bb16061ad522dd22b21d1a3e9
iommu/io-pgtable-arm: Support coherency for Mali LPAE

Midgard GPUs have ACE-Lite master interfaces which allows systems to
integrate them in an I/O-coherent manner. It seems that from the GPU's
viewpoint, the rest of the system is its outer shareable domain, and so
even when snoop signals are wired up, they are only emitted for outer
shareable accesses. As such, setting the TTBR_SHARE_OUTER bit does
indeed get coherent pagetable walks working nicely for the coherent
T620 in the Arm Juno SoC.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/8df778355378127ea7eccc9521d6427e3e48d4f2.1600780574.git.robin.murphy@arm.com
drivers/iommu/io-pgtable-arm.c