cinap_lenrek [Mon, 13 May 2019 17:12:41 +0000 (19:12 +0200)]
bcm, bcm64: preserve memsize across reboots, avoid trashing atags while parsing cmdline
we override atag memory on reboot, so preserve
the memsize learned from atag as *maxmem plan9
variable. the global memsize variable is not
needed anymore.
avoid trashing the following atag when zero
terminating the cmdline string.
cinap_lenrek [Sat, 11 May 2019 23:20:21 +0000 (01:20 +0200)]
devip: do not lock selftab in ipselftabread(), remove unused fields from Ipself
the Ipselftab is designed to not require locking on read
operation. locking the selftab in ipselftabread() risks
deadlock when accessing the user buffer creates a fault.
cinap_lenrek [Sat, 11 May 2019 12:01:26 +0000 (14:01 +0200)]
devip: remove unused c->car qlock, avoid potential deadlock in ipifcregisterproxy()
remove references to the unused Conv.car qlock.
ipifcregisterproxy() is called with the proxy
ifc wlock'd, which means we cannot acquire the
rwlock of the interfaces that will proxy for us
because it is allowed to rlock() multiple ifc's
in any order. to get arround this, we use canrlock()
and skip the interface when we cannot acquire the
lock.
the ifc should get wlock'd only when we are about
to modify the ifc or its lifc chain. that is when
adding or removing addresses. wlock is not required
when we addresses to the selfcache, which has its
own qlock.
cinap_lenrek [Sat, 11 May 2019 05:22:34 +0000 (07:22 +0200)]
devip: avoid media bind/unbind kproc reader startup race, simplify etherbind
mark reader process pointers with (void*)-1 to mean
not started yet. this avoids the race condition when
media unbind happens before the kproc has set its
Proc* pointer. then we would not post the note and
the reader would continue running after unbind.
etherbind can be simplified by reading the #lX/addr
file to get the mac address, avoiding the temporary
buffer.
cinap_lenrek [Fri, 10 May 2019 12:05:04 +0000 (14:05 +0200)]
bcm64: use exclusive monitor on nrdy to wake up idlehands()
when the exclusive monitor is cleared, a event is generated
which we can use to wake up idlehands. that way we do not
need to wait for the next timer interrupt until a cpu takes
work from the run queue.
cinap_lenrek [Tue, 7 May 2019 07:19:53 +0000 (09:19 +0200)]
nusb/usbd: work around devices that ignore the high byte of wLength in control transfer reads
there appear to be devices out there such as Realtek RTL2838UHIDIR
SDR that do not process control transfers correctly, ignoring the
high byte of the wLength field. to work around this, we specify an
odd number of bytes for read sizes >= 256 which keeps the low byte
0xFF.
cinap_lenrek [Sun, 5 May 2019 15:02:37 +0000 (17:02 +0200)]
bootrc: fix $rootdir and $rootspec handling (thanks lucio)
we did not interpret the $rootdir and $rootspec environment
variables right. $rootdir is what gets bound to / (usually /root)
and $rootspec is the mountspec of /root.
i'v been seeing the error condition described above in the
Slowbulkin comment. so i'm enabling the work arround which
seems to fix the lockup.
in the split transaction case where we want to start the
transaction at frame start, acquire the ctlr lock *before*
checking if we are in the right frame number. so the start
will happen atomically. checking the software ctlr->sofchan
instead of checking the interrupt mask register seems to
be quicker.
setting the haint mask bit for the chan under ctlr lock
in chanio() instead of chanwait() avoids needing to acquire
the ctlr lock twice.
mask wakechan bits with busychan bitmap in interrupt handlers
so we will not try to wake up released chans by accident.
sleep() and tsleep() might get interrupted so we have to
release the split qlock in the split transaction case and
in all cases, make sure to halt the channel before release.
add some common debug functions to dump channel and controller
registers.
cinap_lenrek [Wed, 1 May 2019 07:35:51 +0000 (09:35 +0200)]
kernel: insert memory barrier in the scheduler before setting up->mach = nil
we have to ensure that all stores saving the process state
have completed before setting up->mach = nil in the scheduler.
otherwise, another cpu could observe up->mach == nil while
the stores such as the processes p->sched label have not finnished.
cinap_lenrek [Wed, 1 May 2019 06:19:29 +0000 (08:19 +0200)]
vmx: build vmx only for 386 or amd64
vmx uses non portable word unpacking macros, breaking
the build for arm64. vmx only works on a pc anyway.
this forces objtype to 386 on these machines, similar
to what the kernel mkfiles do.
usbxhci: make stuck usb transactions interruptable.
some control transactions can confuse the xhci controller so
much that it even fails to respond to command abort or STOPEP
control command. with no way for us to abort the transaction
but a full controller reset.
we give the controller 5 seconds to abort our initial
transaction and if that fails we wake the recover process
to reset the controller.
from what i can tell, sending port enable is a spec violation.
this fixes a hang during hub enumeration in the ASMedia
xhci controller when i plug in my IBM UltraNav SK-8845.
also, send unsuspend when port is suspended instead of enable.
from the USB 2 specification:
11.24.2.7.1.2 PORT_ENABLE
...
This bit may be set only as a result of a SetPortFeature(PORT_ENABLE).
...
The hub response to a SetPortFeature(PORT_ENABLE) request is not specified.
7c: fix long to vlong/pointer conversion, avoid negative immediate offsets
we have to explicitely convert to vlong by sign or
zero extending as not every operation leaves a proper
zero/sign extended result in the register. for example
NEGW will zero extend, breaking negative int offsets
on pointers.
we explicitely insert SXTW or MOVWU instructions which
the peephole optimizer takes out again when it is safe
todo so.
when promoting constant offsets to immediate offsets,
make sure the offset will be in range. otherwise the
linker will produce not so optimal pointer arithmetic
instructions to calculate the offset.
the possible bitmasks generated depend on the data width
of the instruction, so we introduce C_BITCON32 and C_BITCON64
operand types to keep them apart.
add arm64 c compiler and assembler (thanks charles forsyth)
this is the the initial sync of charles forsyths plan9 c
compiler suite from http://bitbucket.org/plan9-from-bell-labs/9-cc
at changeset version 54:65fb8bb56c59