to select the maximum segment size for each bus_dmamap_load (up to the maxsegsz
supplied to bus_dmamap_create). dm_maxsegsz is reset to the value supplied to
bus_dmamap_create when the dmamap is unloaded.
require that all bus tags have pointers to bus_space_read/write functions,
i.e. no run-time hunting for the first "upstream" implementation.
Since this changes the way bus tags should be constructed it makes sense
to do the same thing for the rest of the bus space methods.
So, now bus space tags are generally constructed by copying the parent's bus
tag and then overriding the methods that the bus driver needs to handle,
instead of starting with an empty bus tag and fiiling in only the fields needed.
enabled on amd64). Add a dmat64 field to various PCI attach structures,
and pass it down where needed. Implement a simple new function called
pci_dma64_available(pa) to test if 64bit DMA addresses may be used.
This returns 1 iff _PCI_HAVE_DMA64 is defined in <machine/pci_machdep.h>,
and there is more than 4G of memory.
bus_space_{read,write}_[1248]() functions, which will allow 16-bit
PCMCIA support to work without additional hacks in MI drivers.
this option is not enabled yet.
perform the translation and recursion if t->ranges != NULL. Make
sbus, cpuunit, and bootbus inherit the parent's map/mmap routines,
and delete the now-unused mapping functions. Update all places where
bus space tags are statically allocated.
"off_t" and the return value is a "paddr_t" to allow mappings
at offsets past 2^31 bytes. Somewhat inspired by FreeBSD, which
only changed the offset to a "vm_offset_t".
Includes updates for the i386, pc532 and sh3 mmmmap from Jason Thorpe.
- the `alignment' and `boundary' arguments in bus_dmamem_alloc() only
serve as hints on how to break up a DMA transaction into chunks
when necessary; it is not necessary on sparc DVMA hardware.
- exclusively use the VM page size (i.e. PAGE_SIZE et.al.) when computing
resource allocations.
- remember the size of DVMA resource allocations in the private `_ds_sgsize'
field in a dma segment descriptor.
"BUS_SPACE_ALIGNED_POINTER()".
Equal to the param.h "ALIGNED_POINTER()" normally, but obeys additional
requirements of the bus_space_xxx_n() macros. (BUS_SPACE_DEBUG)
* In the bus tag structure, keep a reference to the parent bus.
* Express all bus space methods as inline functions in stead of macros
and use the parent bus tag reference to find the nearest "upstream"
bus that implements the method.
