Changes in v2:
XHCI:
- Replaced XHCI and HCD changes with Mathias' XHCI interrupter changes
in his tree:
https://git.kernel.org/pub/scm/linux/kernel/git/mnyman/xhci.git/log/?h=feature_interrupters
Adjustments made to Mathias' changes:
- Created xhci-intr.h to export/expose interrupter APIs versus exposing xhci.h.
Moved dependent structures to this file as well. (so clients can parse out
information from "struct xhci_interrupter")
- Added some basic locking when requesting interrupters.
- Fixed up some sanity checks.
- Removed clearing of the ERSTBA during freeing of the interrupter. (pending
issue where SMMU fault occurs if DMA addr returned is 64b - TODO)