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.
"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.
- returned EOPNOTSUPP rather than -1.
- no check for negative offset.
many of these fix potential security problems in these drivers.
XXX XXX XXX
the d_mmap cdev routine should be changed to have a prototype like:
paddr_t (*d_mmap) __P((dev_t, off_t, int));
by someone!
cascaded and that it will be unmasked when DMA is thawed after being
frozen. (This also has the effect of making sure that no device ever
erroneously gets DRQ 4.)
as the Shark's CS8900 Ethernet, which want to use the DMA controller in
this mode (as opposed to single mode).
[Editor's note: committed from a Shark using a new bus_dma back-end
and a CS8900 driver converted to use the MI code :-]
a struct device * corresponding to the ISA bus device. The ISA DMA
controller driver functions have been renamed and now take a struct
isa_dma_state *, and are called indirectly by machine-dependent code
which provides the DMA state.
These changes allow e.g. `ofisa' (the OpenFirmware configuration
mechanism for the ISA bus, used by e.g. Sharks) to use the MI ISA
DMA controller code.
- It is now possible to handle devices that want "looping" DMA,
e.g. the SoundBlaster correctly. The WSS and SB drivers use this.
To do this several new methods were introduced in audio_hw_if.
- Different silence handling (forced by previous change).
- The audio driver can now be mmap()-ed, but due to problems in
the VM system only for writing for now.
- The OSS (Linux) audio emulation takes advantage of some of the
new features.
christos