Some HW devices are created as child devices of proprietary busses,
that have a bus specific policy defining how the child devices
wires representing the devices ID are translated into IOMMU and
IRQ controllers device IDs.
Current IORT code provides translations for:
- PCI devices, where the device ID is well identified at bus level
as the requester ID (RID)
- Platform devices that are endpoint devices where the device ID is
retrieved from the ACPI object IORT mappings (Named components single
mappings). A platform device is represented in IORT as a named
component node
For devices that are child devices of proprietary busses the IORT
firmware represents the bus node as a named component node in IORT
and it is up to that named component node to define in/out bus
specific ID translations for the bus child devices that are
allocated and created in a bus specific manner.
In order to make IORT ID translations available for proprietary
bus child devices, the current ACPI (and IORT) code must be
augmented to provide an additional ID parameter to acpi_dma_configure()
representing the child devices input ID. This ID is bus specific
and it is retrieved in bus specific code.
By adding an ID parameter to acpi_dma_configure(), the IORT
code can map the child device ID to an IOMMU stream ID through
the IORT named component representing the bus in/out ID mappings.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Link: https://lore.kernel.org/r/20200619082013.13661-6-lorenzo.pieralisi@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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