we were in ledcontrol(), the heartbeat twinkler would just punt on
updating the LED even though it had already updated the status. (This
was broken in v1.73 of locore.s).
Rather than resurrect the old code, simplify ledcontrol() and don't
bother with mutual exclusion. As mentioned by the comments describing
this function, we really don't need to be that precise. We do, however,
want to guarantee instructions that modify the status variable directly,
so the function is now primarily inline assembly.
null, the frstor would fault on a PPro. I'm pretty sure this is not
how the chip is supposed to behave, but it's easy enough to do a fninit
to throw away the exception state.
Also, some other minor changes to the documentation.
ID) when determining if the Vendor ID is invalid. The spec says that
Vendor ID of 0xffff is invalid, so, it doesn't _matter_ what the product
ID is in that case. Treat Vendor ID 0 as invalid because we always have.
RTO estimation changes. Under some circumstances it would return a value
of 0, while the old Van Jacobson RTO code would return a minimum of 3.
This would result in 12 retransmissions, each 1 second apart.
This takes care of those instances, and ensures that t_rttmin is
used everywhere as a lower bound.
the very rare case of shared mappings that have amap's attached in a
reasonable way -- this is not currently causing any problems, but i
fixed it anyway. update the comment in this section of code and also
be smarter about avoiding needless calls to pmap_protect().
change pfil_add_hook to put output filters at the tail of the queue,
while continuing to place input filters at the head of the queue. update
the two users of these functions, and document these changes.
fixes PR#4593.
invalidation algorithm:
if (old mapping had PG_ASM set || pmap is active) {
TIBS(va);
if (also sync I-stream)
imb();
}
The check for "old mapping had PG_ASM" will get all kernel mappings (since
kernel mappings always have PG_ASM set).
This allows us to remove the bogus check for the kernel pmap in
active_pmap() - do so.
Use the new TLB invalidation macro whenever such action is needed.
as well, until some other changes are made). Nuke active_user_pmap(),
and change the places that used it to use active_pmap() instead (as well
as make some DIAGNOSTIC consistency checks).
the PTE was previously invalid, no TLB invalidation is necessary because:
(1) when a PTE is invalidated, its entry is flushed from the
TLB
(2) the PALcode won't install an invalid PTE into the TLB.
structure. We will continue to run on this context (which is the
global Lev1map at this point) right up until we switch to proc0's
context in switch_exit().
