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powerpc/iommu: Enable remaining IOMMU Pagesizes present in LoPAR
authorLeonardo Bras <leobras.c@gmail.com>
Thu, 8 Apr 2021 20:19:16 +0000 (17:19 -0300)
committerMichael Ellerman <mpe@ellerman.id.au>
Wed, 14 Apr 2021 13:04:16 +0000 (23:04 +1000)
commit472724111f0f72042deb6a9dcee9578e5398a1a1
tree3856b1ee1b5366aa0610628da442903bb2a069cc
parent672bff581e19d5d7bef993f910ed385c4054cbbc
powerpc/iommu: Enable remaining IOMMU Pagesizes present in LoPAR

According to LoPAR, ibm,query-pe-dma-window output named "IO Page Sizes"
will let the OS know all possible pagesizes that can be used for creating a
new DDW.

Currently Linux will only try using 3 of the 8 available options:
4K, 64K and 16M. According to LoPAR, Hypervisor may also offer 32M, 64M,
128M, 256M and 16G.

Enabling bigger pages would be interesting for direct mapping systems
with a lot of RAM, while using less TCE entries.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210408201915.174217-1-leobras.c@gmail.com
arch/powerpc/platforms/pseries/iommu.c