--Remove special-case handling of sparc64 bus_dmamap* functions.
Replace with a more generic mechanism that allows MD busdma
implementations to generate inline mapping functions by
defining WANT_INLINE_DMAMAP in <machine/bus_dma.h>. This
is currently useful for sparc64, x86, and arm64, which all
implement non-load dmamap operations as simple wrappers
around map objects which may be bus- or device-specific.
--Remove NULL-checked bus_dmamap macros. Implement the
equivalent NULL checks in the inlined x86 implementation.
For non-x86 platforms, these checks are a minor pessimization
as those platforms do not currently allow NULL maps. NULL
maps were originally allowed on arm64, which appears to have
been the motivation behind adding arm[64]-specific barriers
to bus_dma.h, but that support was removed in r299463.
--Simplify the internal interface used by the bus_dmamap_load*
variants and move it to bus_dma_internal.h
--Fix some drivers that directly include sys/bus_dma.h
despite the recommendations of bus_dma(9)
Reviewed by: kib (previous revision), marius
Differential Revision: https://reviews.freebsd.org/D10729
The x86 busdma subsystem allows using multiple implementations.
By default the classic bounce buffer approach is used, however
on systems with IOMMU it could be in runtime switched to more
efficient hardware accelerated implementation.
This commit adds ARM64 port of the x86 busdma framework and bounce
buffer backend. It is ready to use on IO coherent systems. If the
IO coherency cannot be guaranteed, the cache management operations have
to be added to this code in places marked by /* XXX ARM64TODO (...) */
comments. Also IOMMU support might be added by registering another
busdma implementation like it is already done on the x86.
Reviewed by: andrew, emaste
Obtained from: Semihalf
Sponsored by: The FreeBSD Foundation
