freebsd-dev/sys/sparc64/central
Marius Strobl 33368e9fe8 Rototill the sparc64 nexus(4) (actually this brings in the code the
sun4v nexus(4) in turn is based on):
o Change nexus(4) to manage the resources of its children so the
  respective device drivers don't need to figure them out of OFW
  themselves.
o Change nexus(4) to provide the ofw_bus KOBJ interface instead of
  using IVARs for supplying the OFW node and the subset of standard
  properties of its children. Together with the previous change this
  also allows to fully take advantage of newbus in that drivers like
  fhc(4), which attach on multiple parent busses, no longer require
  different bus front-ends as obtaining the OFW node and properties
  as well as resource allocation works the same for all supported
  busses. As such this change also is part 4/4 of allowing creator(4)
  to work in USIII-based machines as it allows this driver to attach
  on both nexus(4) and upa(4). On the other hand removing these IVARs
  breaks API compatibility with the powerpc nexus(4) but which isn't
  that bad as a) sparc64 currently doesn't share any device driver
  hanging off of nexus(4) with powerpc and b) they were no longer
  compatible regarding OFW-related extensions at the pci(4) level
  since quite some time.
o Provide bus_get_dma_tag methods in nexus(4) and its children in
  order to handle DMA tags in a hierarchical way and get rid of the
  sparc64_root_dma_tag kludge. Together with the previous two items
  this changes also allows to completely get rid of the nexus(4)
  IVAR interface. It also includes:
  - pushing the constraints previously specified by the nexus_dmatag
    down into the DMA tags of psycho(4) and sbus(4) as it's their
    IOMMUs which induce these restrictions (and nothing at the
    nexus(4) or anything that would warrant specifying them there),
  - fixing some obviously wrong constraints of the psycho(4) and
    sbus(4) DMA tags, which happened to not actually be used with
    the sparc64_root_dma_tag kludge in place and therefore didn't
    cause problems so far,
  - replacing magic constants for constraints with macros as far
    as it is obvious as to where they come from.
  This doesn't include taking advantage of the newbus way to get
  the parent DMA tags implemented by this change in order to divorce
  the IOTSBs of the PCI and SBus IOMMUs or for implementing the
  workaround for the DMA sync bug in Sabre (and Tomatillo) bridges,
  yet, though.
o Get rid of the notion that nexus(4) (mostly) reflects an UPA bus
  by replacing ofw_upa.h and with ofw_nexus.h (which was repo-copied
  from ofw_upa.h) and renaming its content, which actually applies to
  all of Fireplane/Safari, JBus and UPA (in the host bus case), as
  appropriate.
o Just use M_DEVBUF instead of a separate M_NEXUS malloc type for
  allocating the device info for the children of nexus(4). This is
  done in order to not need to export M_NEXUS when deriving drivers
  for subordinate busses from the nexus(4) class.
o Use the DEFINE_CLASS_0() macro to declare the nexus(4) driver so
  we can derive subclasses from it.
o Const'ify the nexus_excl_name and nexus_excl_type arrays as well
  as add 'associations' and 'rsc', which are pseudo-devices without
  resources and therefore of no real interest for nexus(4), to the
  former.
o Let the nexus(4) device memory rman manage the entire 64-bit address
  space instead of just the UPA_MEMSTART to UPA_MEMEND subregion as
  Fireplane/Safari- and JBus-based machines use multiple ranges,
  which can't be as easily divided as in the case of UPA (limiting
  the address space only served for sanity checking anyway).
o Use M_WAITOK instead of M_NOWAIT when allocating the device info
  for children of nexus(4) in order to give one less opportunity
  for adding devices to nexus(4) to fail.
o While adapting the drivers affected by the above nexus(4) changes,
  change them to take advantage of rman_get_rid() instead of caching
  the RIDs assigned to allocated resources, now that the RIDs of
  resources are correctly set.
o In iommu(4) and nexus(4) replace hard-coded functions names, which
  actually became outdated in several places, in panic strings and
  status massages with __func__. [1]
o Use driver_filter_t in prototypes where appropriate.
o Add my copyright to creator(4), fhc(4), nexus(4), psycho(4) and
  sbus(4) as I changed considerable amounts of these drivers as well
  as added a bunch of new features, workarounds for silicon bugs etc.
o Fix some white space nits.

Due to lack of access to Exx00 hardware, these changes, i.e. central(4)
and fhc(4), couldn't be runtime tested on such a machine. Exx00 are
currently reported to panic before trying to attach nexus(4) anyway
though.

PR:		76052 [1]
Approved by:	re (kensmith)
2007-03-07 21:13:51 +00:00
..
central.c