the page attribute table was initialized in mmuinit(), which is
too late for bootscreen(). So now we check for PAT support and
insert the write-combine entry early in cpuidentify().
this might have been the cause of some slow EFI framebuffers on
machines with overlapping or insufficient MTRR entries.
ipiput4() and ipiput6() are called with the incoming interface rlocked
while ipoput4() and ipoput6() also rlock() the outgoing interface once
a route has been found. it is common that the incoming and outgoing
interfaces are the same recusive rlocking().
the deadlock happens when a reader holds the rlock for the incoming interface,
then ip/ipconfig tries to add a new address, trying to wlock the interface.
as there are still active readers on the ifc, ip/ipconfig process gets queued
on the inteface RWlock.
now the reader finds the outgoing route which has the same interface as the
incoming packet and tries to rlock the ifc again. but now theres a writer
queued, so we also go to sleep waiting four outselfs to release the lock.
the solution is to never wait for the outgoing interface rlock, but instead
use non-queueing canrlock() and if it cannot be acquired, discard the packet.
do not touch s->map on SG_PHYSICAL type segments as they do
not have a pte map (s->mapsize == 0 && s->map == nil).
also remove the SG_PHYSICAL switch in freepte(), this is never
reached.
the calculation for the control endpoint0 output device context
missed the context size scaling shift, resulting in botched
stall handling as we would not read the correct endpoint status
value.
note, this calculation only affected control endpoint 0, which
was handled separately from all other endpoints.
spectacular bug. cmpswap() had a sign extension bug
using sign extending MOV to load the old compare
value and LDXRW using zero extension while the CMP
instruction compared 64 bit registers.
this caused cmpswap with negative old value always
to fail.
interestingly, libc's version of this function was
fine.
when reclaiming pages from an image, always reclaim all
the hash chains equally. that way, we avoid being biased
towards the chains at the start of the Image.pghash[] array.
images can be in two states: active or inactive. inactive
images are the ones which are not used by program while
active ones aare.
when reclaiming pages, we should try to reclaim pages
from inactive images first and only if that set becomes
exhausted attempt to release text pages and attempt to
reclaim pages from active images.
when we run out of Image structures, it makes only sense
to reclaim pages from inactive images, as reclaiming pages
from active ones will never free any Image structures.
change putimage() to require a image already locked and
make it unlock the image. this avoids many pointless
unlock()/lock() sequences as all callers of putimage()
already had the image locked.
looks like linux changed the device tree names for
the memory node:
4b17654f51 (diff-ac03c9402b807c11d42edc9e8d03dfc7)
this fixes the memory size detection with latest firmware
on raspberry pi4-b (4GB) for kenji.
The swcursor used a 32x32 image for saving/restoring
screen contents for no reason.
Add a doflush argument to swcursorhide(), so that
disabling software cursor with a double buffered
softscreen is properly hidden. The doflush parameter
should be set to 0 in all other cases as swcursordraw()
will flushes both (current and previours) locations.
Make sure swcursorinit() and swcursorhide() clear the
visibility flag, even when gscreen is nil.
Remove the cursor locking and just do everything within
the drawlock. All cursor functions such as curson(),
cursoff() and setcursor() will be called drawlock
locked. This also means &cursor can be read.
Fix devmouse cursor reads and writes. We now have the
global cursor variable that is only modified under
the drawlock. So copy under drawlock.
Move the pc software cursor implementation into vgasoft
driver, so screen.c does not need to handle it as
a special case.
Remove unused functions such as drawhasclients().
most pc's are multiprocessors these days, that use apic or
msi interrupts, then the irq does not matter anymore. and
uefi does not even assign irq to pci devices anymore. if
we have a problem enabling an interrupt, we will print.
memory returned by rampage() is not zeroed, so we have to
zero it ourselfs. apparently, this bug didnt show up as we
where zeroing conventional low memory before the new memory
map code. also rampage() never returns nil.
This replaces the memory map code for both pc and pc64
kernels with a unified implementation using the new
portable memory map code.
The main motivation is to be robust against broken
e820 memory maps by the bios and delay the Conf.mem[]
allocation after archinit(), so mp and acpi tables
can be reserved and excluded from user memory.
There are a few changes:
new memreserve() function has been added for archinit()
to reserve bios and acpi tables.
upareserve() has been replaced by upaalloc(), which now
has an address argument.
umbrwmalloc() and umbmalloc() have been replaced by
umballoc().
both upaalloc() and umballoc() return physical addresses
or -1 on error. the physical address -1 is now used as
a sentinel value instead of 0 when dealing with physical
addresses.
archmp and archacpi now always use vmap() to access
the bios tables and reserve the ranges. more overflow
checks have been added.
ramscan() has been rewritten using vmap().
to handle the population of kernel memory, pc and pc64
now have pmap() and punmap() functions to do permanent
mappings.
This is a generic memory map for physical addresses. Entries
can be added with memmapadd() giving a range and a type.
Ranges can be allocated and freed from the map. The code
automatically resolves overlapping ranges by type priority.
Fix the inconsistent use of ether->mem. Always use physical
addresses. Let ether8390 convert to virtual addresses using
KADDR() when we have to copy data in/out.
the previous mkfile had a sneaky hack that would use
sed to delete the first 2 lines of hex output to strip
the 32 byte long a.out header for apbootstrap and rebootcode.
use 8l -H3 flag to strip the header from the output file.
the rc & operator changes stdin to /dev/null, so we
have to do the <[0=1] inside the {}
this never showed up as an issue because many
fileservers just read 9p messages from standard
output.
