powerpc/pseries/iommu: create DDW for devices with DMA mask less than 64-bits

Eder Zulianrequested to merge
ezulian/centos-stream-9:rhel-104297 into main

powerpc/pseries/iommu: create DDW for devices with DMA mask less than 64-bits

JIRA: https://issues.redhat.com/browse/RHEL-104297

Upstream Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

commit 67dfc11982f7e3c37f0977e74671da2391b29181
Author: Gaurav Batra <gbatra@linux.ibm.com>
Date:   Wed Jan 8 10:48:14 2025 -0600

    powerpc/pseries/iommu: create DDW for devices with DMA mask less than 64-bits

    Starting with PAPR level 2.13, platform supports placing PHB in limited
    address mode. Devices that support DMA masks less that 64-bit but greater
    than 32-bits are placed in limited address mode. In this mode, the
    starting DMA address returned by the DDW is 4GB.

    When the device driver calls dma_supported, with mask less then 64-bit, the
    PowerPC IOMMU driver places PHB in the Limited Addressing Mode before
    creating DDW.

    Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
    Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
    Link: https://patch.msgid.link/20250108164814.73250-1-gbatra@linux.ibm.com

Signed-off-by: Eder Zulian ezulian@redhat.com

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