UVM pmap's locking protocol, written by Chuck Cranor. Not all of the
support for multiple processors is here yet, but the kernel does run
under moderate loads with LOCKDEBUG (all locking operations are no-ops
unless LOCKDEBUG is turned on).
This is by no means complete... there are still some possible snares
to take a look at.
pv_changepte(). Reason: the managed() macro does not take into
account the gap in the managed pages range that may have been introduced
by the page table allocation in bootstrap().
lots of data, e.g. ~18k on a PCI system with few add-in devices; use
with MSGBUFSIZE=...). Useful to have here so that people who want as
much data about the PCI configuration in a machine can get it without
having to craft their own code. Also, clean up a few of the other
#if 0'd printfs.
* print all configuration space registers. Then, where possible,
interpret them. (That is, PRESENT ALL THE DATA, then interpret it --
don't hide data behind interpretation. Also, when interpreting
fields, try to print out the specific value that's being interpreted.)
* handle different header types.
* allow caller to specify a function which can interpret the
device-dependent header and is responsible for pretty-printing it.
It spews (use 'options MSGBUFSIZE=...' 8-), but when you want the data,
you really want _all_ of it.
Still needs some cleanup and additional code (e.g. interepretation
of PCI-PCI (type 1) and PCI-Cardbus (type 2(?)) bridge headers).
pci_mapreg_info() call. pci_mapreg_map() implies this check,
but code which calls pci_mapreg_info() has to check it explicitly.
Otherwise, if memory space is disabled, the driver does the wrong
thing, and tries to use memory space anyway, potentially resulting
incorrect driver operation and no useful error message.
* we already have the vnode interlock, so vref() should not ask for it again.
* we call VOP_RECLAIM/VOP_INACTIVE(), which shouldn't be duplicated in vrele().