its only user in pciide_common.c. Also redefine NIDEDMA_TABLES to match
the max DMA transfer size specified in the call to bus_dmamap_create()
(IDEDMA_BYTE_COUNT_MAX instead of MAXPHYS).
The macro is also redefined to handle devices that have a PAGE_SIZE greater
than sc_dma_maxsegsz (buggy revision of satalink 3112 on ibm4xx).
in a different fashion. Individually, they have the same functionality,
but their layout is different. An example of such a chipset is
the Promise 203xx.
To be able to deal with this, transform the cmd and dma bus_space handles
into an array of handles, each seperately created with bus_space_subregion.
The code generated by using the extra indirection shouldn't change much,
since the extra indirection is negated by having the offset calculation
already done in bus_space_subregion. E.g.
bus_space_write_4(tag, handle, offset, value)
becomes
bus_space_write_4(tag, handles[offset], 0, value)
Reviewed by Manuel Bouyer. Tested on wdc_isa, wdc_pcmcia, viaide, piixide (i386)
and on cmdide (sparc64).
