are met:
1) The BIOS indicates that there is exactly 64MB of RAM, and
2) The memory size isn't specified with the MAXMEM option or
the npx0 msize hack,
...then do a speculative memory probe beyond the 64MB's until the
first bad page is encountered. This is an admitted hack, but should
nonetheless deal with detecting the correct amount of memory in nearly
all of the modern systems with >64MB of RAM.
Also made a change that will cause the list of detected memory chunks
to be printed if bootverbose is set.
2) Added a non_blocking flag to the write routine.
3) Added a 3rd buffer (actually a ring buffer would be better)
Submitted by: Jim Lowe <james@miller.cs.uwm.edu>
holding CPU along with the lock. When a CPU fails to get the lock
it compares its own id to the holder id. If they are the same it
panic()s, as simple locks are binary, and this would cause a deadlock.
Controlled by smptests.h: SL_DEBUG, ON by default.
Some minor cleanup.
and hardware.
There is now another simple_lock around clock data/hardware accesses in
clock.c and microtime.s. It is my belief that this is the only area
sio/cy might stumble into during an unblocked INTerrupt. Thus I separated
the sio/cy code from the generic disable_intr()/enable_intr() routines.
Controlled by smptests.h: USE_COMLOCK, ON by default.
Add a simplelock to deal with disable_intr()/enable_intr() as used in UP kernel.
UP kernel expects that this is enough to guarantee exclusive access to
regions of code bracketed by these 2 functions.
Add a simplelock to bracket clock accesses in clock.c: clock_lock.
Help from: Bruce Evans <bde@zeta.org.au>
and the sound driver which uses auto dma.
The dma interface functionality remains however it now checks
to see if a dma is operating in auto dma mode and if so it bypasses
the busy flag check . I have modified the sound driver 3.5 to
adjust for this new behavior and tested it under FreeBSD 3.0 -current
This patch also includes the new function isa_dmastop.
Submitted by: Amancio Hasty <hasty@rah.star-gate.com>
smp_active = 1 used to indicate that the system had frozen previously
started AP's, while smp_active = 0 was "AP's not yet started". I have split
this into smp_started (which is set when the AP's come online), and
smp_active is left for turning on/off AP scheduling.
- We now have enough per-cpu idle context, the real idle loop has been
revived (cpu's halt now with nothing to do).
- Some preliminary support for running some operations outside the
global lock (eg: zeroing "free but not yet zeroed pages") is present
but appears to cause problems. Off by default.
- the smp_active sysctl now behaves differently. It's merely a 'true/false'
option. Setting smp_active to zero causes the AP's to halt in the idle
loop and stop scheduling processes.
- bootstrap is a lot safer. Instead of sharing a statically compiled in
stack a number of times (which has caused lots of problems) and then
abandoning it, we use the idle context to boot the AP's directly. This
should help >2 cpu support since the bootlock stuff was in doubt.
- print physical apic id in traps.. helps identify private pages getting
out of sync. (You don't want to know how much hair I tore out with this!)
More cleanup to follow, this is more of a checkpoint than a
'finished' thing.
