powerpc/kernel/iommu: Add new iommu_table_in_use() helper

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Having a function to check if the iommu table has any allocation helps
deciding if a tbl can be reset for using a new DMA window.

It should be enough to replace all instances of !bitmap_empty(tbl...).

iommu_table_in_use() skips reserved memory, so we don't need to worry about
releasing it before testing. This causes iommu_table_release_pages() to
become unnecessary, given it is only used to remove reserved memory for
testing.

Also, only allow storing reserved memory values in tbl if they are valid
in the table, so there is no need to check it in the new helper.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210817063929.38701-3-leobras.c@gmail.com

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Leonardo Bras 2021-08-17 03:39:20 -03:00 • committed by Michael Ellerman

parent 0c634bafe3

commit 3c33066a21

2 changed files with 32 additions and 30 deletions

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arch/powerpc/include/asm/iommu.h

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arch/powerpc/kernel/iommu.c

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