isa_dmamap_create() calls to their open/close entrypoints. This worked
with some luck, but broke on i386 when _bus_dmamap_create started
to allocate bounce buffers upfront, since memory below 16M may well
not be available when the sound devices is opened for the Nth time.
To fix this, create a new simple interface, isa_drq_alloc/isa_drq_free,
wrappers around already existing bitmask macros. These are expected
to be used before an isa_dmamap_create call, and after an
isa_dmamap_destroy call, respectively. For the sb and ad1848 drivers,
they're deferred until open/close.
All isa_dmamap_create calls can now use BUS_DMA_ALLOCNOW and be done
at attach time.
malloc types into a structure, a pointer to which is passed around,
instead of an int constant. Allow the limit to be adjusted when the
malloc type is defined, or with a function call, as suggested by
Jonathan Stone.
support for it and we're configured for separate play and record
DRQs. This makes full-duplex audio work on the Windows Sound System
(found in many Alpha systems).
Submitted by Juergen Weiss <weiss@uni-mainz.de> in kern/11178.
"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.