This will allow improvements to the pmaps so that they can more easily defer expensive operations, eg tlb/cache flush, til the last possible moment.
Currently this is a no-op on most platforms, so they should see no difference.
Reviewed by Jason.
hardware-assisted soft interrupts on all boards.
(Note: VMEChip2-less 162/172 not yet tested)
This greatly simplifies the `rei' path and allows
interrupt nesting to be tracked somewhat more easily.
As a result we now have a working CLKF_INTR() macro
and can detect uvm_fault() being called from an interrupt
(although there may still be a very short race detecting
the latter; need to investigate further).
Basically, bus_dmamap_sync() `PREREAD' needs to flush the cache
for the start and end of the region if it is not aligned to
a cacheline boundary, otherwise a subsequent POSTREAD can *purge*
valid data which was in the cacheline but *outside* the region
passed to bus_dmamap_sync().
Bus snooping doesn't always help here because osiop(4) calls
bus_dmamap_sync() with POSTREAD even if no data was actually
transferred! (And we can't rely on snooping on the 68060 models anyway).
each vm_page structure. Add a VM_MDPAGE_INIT() macro to init this
data when pages are initialized by UVM. These macros are mandatory,
but ports may #define them to nothing if they are not needed/used.
This deprecates struct pmap_physseg. As a transitional measure,
allow a port to #define PMAP_PHYSSEG so that it can continue to
use it until its pmap is converted to use VM_MDPAGE_MEMBERS.
Use all this stuff to eliminate a lot of extra work in the Alpha
pmap module (it's smaller and faster now). Changes to other pmap
modules will follow.
call overhead is incurred as we start sprinkling pmap_update() calls
throughout the source tree (no pmaps currently defer operations, but
we are adding the infrastructure to allow them to do so).
and place the definition in <machine/types.h>. This can now be used
as a flag to indicate whether or not <machine/intr.h> can be included
to get the generic soft interrupt API.
. use a structure for the tag instead of an integer constant,
. add bus_space_{peek,poke}_N() (and G/C `badaddr()'),
. fix a few drivers which have dependencies on the implementation.
CPU support taken from a combination of NetBSD/amiga and NetBSD/x68k.
At this time, MVME-172 works but MVME-177 is untested. Since the '177
is otherwise identical to the MVME-167, this should *just work*.
