Landon J. Fuller 9ed453245b bhnd(4): Add support for querying DMA address translation parameters
BHND Wi-Fi chipsets and SoCs share a common DMA engine, operating within
backplane address space. To support host DMA on Wi-Fi chipsets, the bridge
core maps host address space onto the backplane; any host addresses must
be translated to their corresponding backplane address.


- Defines a new bhnd_get_dma_translation(9) API to support querying DMA
  address translation parameters from the bhnd(4) bus.
- Extends bhndb(4) to provide DMA translation descriptors from a DMA
  address translation table defined in the host bridge-specific
  bhndb_hwcfg.
- Defines bhndb(4) DMA address translation tables for all supported host
  bridge cores.
- Extends mips/broadcom's bhnd_nexus driver to return an identity (no-op)
  DMA translation descriptor; no translation is required when addressing
  the SoC backplane.

Approved by:	adrian (mentor)
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D12582
2017-11-21 23:25:22 +00:00
..
2017-10-29 08:17:03 +00:00