class Iommu

Check if |bus_txn_id| is valid for this IOMMU (i.e. could be used

to configure a device).

Grant the device identified by |bus_txn_id| access to the range of

pages given by [offset, offset + size) in |vmo|. An opaque token that

represents the mapping is returned, and this token can be given to |Unmap|

or |QueryAddress|.

The memory in the given range of |vmo| MUST have been pinned before

calling this function, and if this function returns ZX_OK,

MUST NOT be unpinned until after Unmap() is called on the returned range.

|perms| defines the access permissions, using the IOMMU_FLAG_PERM_*

flags.

If |size| is no more than |minimum_contiguity()|, this will never return

a partial mapping.

Returns ZX_ERR_INVALID_ARGS if:

|size| is zero.

|offset| is not aligned to kPageSize

Returns ZX_ERR_OUT_OF_RANGE if [offset, offset + size) is not a valid range in |vmo|.

Returns ZX_ERR_NOT_FOUND if |bus_txn_id| is not valid.

Returns ZX_ERR_NO_RESOURCES if the mapping could not be made due to lack

of an available address range.

Same as Map, but with additional guarantee that this will never return a

partial mapping. It will either return a single contiguous mapping or

return a failure.

Queries the information of a mapping created by |Map*|, identified by

|map_token| for the device |bus_txn_id|. The portion of the mapping to

query is identified by |map_offset|, with the provided |size| merely being

a hint of the range the caller is interested in. Fills out |vaddr| with the

mapped address that corresponds to the |map_offset|, and |mapped_len| with

the contiguity of the mapping at that point.

ALthough |size| is a hint, the caller is required to ensure that

|size + map_offset| falls within the original |size| provided to the |Map*|

call.

The returned |mapped_len| could be less than, equal or greater than the

specified size. In the case of being less than, additional contiguous

ranges can be found by calling again with a new |map_offset|.

Returns ZX_ERR_INVALID_ARGS if:

|map_token| is not from a valid |Map*|.

|map_offset| is not aligned to kPageSize.

Returns ZX_ERR_OUT_OF_RANGE if [map_offset, map_offset + size) is not a

valid range in the mapping.

Returns ZX_ERR_NOT_FOUND if |bus_txn_id| is not valid.

Revoke access to the range of addresses identified by the |map_token|,

must have been previously returned by a |Map*| call, and the size of that

mapping, for the device identified by |bus_txn_id|.

Returns ZX_ERR_INVALID_ARGS if:

|size| is not a multiple of kPageSize

Returns ZX_ERR_NOT_FOUND if |bus_txn_id| is not valid.

Remove all mappings for |bus_txn_id|.

Returns ZX_ERR_NOT_FOUND if |bus_txn_id| is not valid.

Returns the number of bytes that Map() can guarantee, upon success, to find

a contiguous address range for. This function is only returns meaningful

values if |IsValidBusTxnId(bus_txn_id)|.

Returns the total size of the space the addresses are mapped into. This

function is only returns meaningful values if |IsValidBusTxnId(bus_txn_id)|.