• W
    iommu: provide early initialisation hook for IOMMU drivers · 1cd076bf
    Will Deacon 提交于
    IOMMU drivers must be initialised before any of their upstream devices,
    otherwise the relevant iommu_ops won't be configured for the bus in
    question. To solve this, a number of IOMMU drivers use initcalls to
    initialise the driver before anything has a chance to be probed.
    
    Whilst this solves the immediate problem, it leaves the job of probing
    the IOMMU completely separate from the iommu_ops to configure the IOMMU,
    which are called on a per-bus basis and require the driver to figure out
    exactly which instance of the IOMMU is being requested. In particular,
    the add_device callback simply passes a struct device to the driver,
    which then has to parse firmware tables or probe buses to identify the
    relevant IOMMU instance.
    
    This patch takes the first step in addressing this problem by adding an
    early initialisation pass for IOMMU drivers, giving them the ability to
    store some per-instance data in their iommu_ops structure and store that
    in their of_node. This can later be used when parsing OF masters to
    identify the IOMMU instance in question.
    Acked-by: NArnd Bergmann <arnd@arndb.de>
    Acked-by: NJoerg Roedel <jroedel@suse.de>
    Acked-by: NMarek Szyprowski <m.szyprowski@samsung.com>
    Tested-by: NRobin Murphy <robin.murphy@arm.com>
    Signed-off-by: NWill Deacon <will.deacon@arm.com>
    1cd076bf
of_iommu.c 3.1 KB