with pmaps. When the context numbers wrap around we flush all user mappings
from the tlb. This makes use of the array indexed by cpuid to allow a pmap
to have a different context number on a different cpu. If the context numbers
are then divided evenly among cpus such that none are shared, we can avoid
sending tlb shootdown ipis in an smp system for non-shared pmaps. This also
removes a limit of 8192 processes (pmaps) that could be active at any given
time due to running out of tlb contexts.
Inspired by: the brown book
Crucial bugfix from: tmm
virtual page number in a much more convenient way; all in one piece. This
greatly simplifies the comparison for a matching tte, and allows the fault
handlers to be much simpler due to not having to load wierd masks.
Rewrite the tlb fault handlers to account for the new format. These are also
written to allow faults on the user tsb inside of the fault handlers; the
kernel fault handler must be aware of this and not clobber the other's
registers. The faults do not yet occur due to other support that is needed
(and still under my desk).
Bug fixes from: tmm
will be used to reduce the number of tlb shootdown ipis in an smp system
by sending one ipi for a whole range of pages, instead of one per page.
Munge the context demap operations slightly to support demapping a non-primary
context.
their duration. This is still only effective as long as they are
only used in the static kernel. Code in modules may cause instruction
faults which makes these break in different ways anyway.
2. Add a load bearing membar #Sync.
3. Add an inline for demapping an entire context.
Submitted by: tmm (1, 2)
- mostly complete kernel pmap support, and tested but currently turned
off userland pmap support
- low level assembly language trap, context switching and support code
- fully implemented atomic.h and supporting cpufunc.h
- some support for kernel debugging with ddb
- various header tweaks and filling out of machine dependent structures
