this used to be slightly cleaner than using ifdefs in a few places to
support both a.out and elf, but using it now just causes messes and
unportabilities. It seems to be impossible to implement the elf
HIDENAME() portably in cpp (since token pasting of "." and <name> is
invalid).
*/prof_machdep.c:
- Removed all uses of CNAME(). CNAME() is easy enough to use in pure
asm code, but using it in inline asm requires messy quoting. The
core pure asm code has been hacked on more and all uses of CNAME() in
it have already gone away. Just assume the elf convention here too.
- Removed now-uneeded include of <machine/asmacros.h>.
- Removed the workaround for a namespace conflict with this include.
profiling is configured but high resolution profiling is not configured.
Only functions in *.[Ss] called the stub, so efficiency was not
significantly affected.
(PICs) rather than interrupt sources. This allows interrupt controllers
with no interrupt pics (such as the 8259As when APIC is in use) to
participate in suspend/resume.
- Always register the 8259A PICs even if we don't use any of their pins.
- Explicitly reset the 8259As on resume on amd64 if 'device atpic' isn't
included.
- Add a "dummy" PIC for the local APIC on the BSP to reset the local APIC
on resume. This gets suspend/resume working with APIC on UP systems.
SMP still needs more work to bring the APs back to life.
The MFC after is tentative.
Tested by: anholt (i386)
Submitted by: Andrea Bittau <a.bittau at cs.ucl.ac.uk> (3)
MFC after: 1 week
Split subr_clock.c in two parts (by repo-copy):
subr_clock.c contains generic RTC and calendaric stuff. etc.
subr_rtc.c contains the newbus'ified RTC interface.
Centralize the machdep.{adjkerntz,disable_rtc_set,wall_cmos_clock}
sysctls and associated variables into subr_clock.c. They are
not machine dependent and we have generic code that relies on being
present so they are not even optional.
POSIX (susv3) requires this, but it is unclear what should be inherited,
duplicating whole 387 stack for new thread seems to be unnecessary and
dangerous. Revert to previous code, force a new thread to be started with
clean FP state.
earlier in cpu_setregs().
- If we know this CPU has a FPU via cpuid, then just assume the INT16
interface and make the npx device quiet to not clutter the dmesg. This
is true for all Pentium and later CPUs and even some of the later 486dx
CPUs.
Reviewed by: bde
Tested by: ps
MFC after: 1 week
- Throw out all of the logical APIC ID stuff. The Intel docs are somewhat
ambiguous, but it seems that the "flat" cluster model we are currently
using is only supported on Pentium and P6 family CPUs. The other
"hierarchy" cluster model that is supported on all Intel CPUs with
local APICs is severely underdocumented. For example, it's not clear
if the OS needs to glean the topology of the APIC hierarchy from
somewhere (neither ACPI nor MP Table include it) and setup the logical
clusters based on the physical hierarchy or not. Not only that, but on
certain Intel chipsets, even though there were 4 CPUs in a logical
cluster, all the interrupts were only sent to one CPU anyway.
- We now bind interrupts to individual CPUs using physical addressing via
the local APIC IDs. This code has also moved out of the ioapic PIC
driver and into the common interrupt source code so that it can be
shared with MSI interrupt sources since MSI is addressed to APICs the
same way that I/O APIC pins are.
- Interrupt source classes grow a new method pic_assign_cpu() to bind an
interrupt source to a specific local APIC ID.
- The SMP code now tells the interrupt code which CPUs are avaiable to
handle interrupts in a simpler and more intuitive manner. For one thing,
it means we could now choose to not route interrupts to HT cores if we
wanted to (this code is currently in place in fact, but under an #if 0
for now).
- For now we simply do static round-robin of IRQs to CPUs when the first
interrupt handler just as before, with the change that IRQs are now
bound to individual CPUs rather than groups of up to 4 CPUs.
- Because the IRQ to CPU mapping has now been moved up a layer, it would
be easier to manage this mapping from higher levels. For example, we
could allow drivers to specify a CPU affinity map for their interrupts,
or we could allow a userland tool to bind IRQs to specific CPUs.
The MFC is tentative, but I want to see if this fixes problems some folks
had with UP APIC kernels on 6.0 on SMP machines (an SMP kernel would work
fine, but a UP APIC kernel (such as GENERIC in RELENG_6) would lose
interrupts).
MFC after: 1 week
passing a pointer to an opaque clockframe structure and requiring the
MD code to supply CLKF_FOO() macros to extract needed values out of the
opaque structure, just pass the needed values directly. In practice this
means passing the pair (usermode, pc) to hardclock() and profclock() and
passing the boolean (usermode) to hardclock_cpu() and hardclock_process().
Other details:
- Axe clockframe and CLKF_FOO() macros on all architectures. Basically,
all the archs were taking a trapframe and converting it into a clockframe
one way or another. Now they can just extract the PC and usermode values
directly out of the trapframe and pass it to fooclock().
- Renamed hardclock_process() to hardclock_cpu() as the latter is more
accurate.
- On Alpha, we now run profclock() at hz (profhz == hz) rather than at
the slower stathz.
- On Alpha, for the TurboLaser machines that don't have an 8254
timecounter, call hardclock() directly. This removes an extra
conditional check from every clock interrupt on Alpha on the BSP.
There is probably room for even further pruning here by changing Alpha
to use the simplified timecounter we use on x86 with the lapic timer
since we don't get interrupts from the 8254 on Alpha anyway.
- On x86, clkintr() shouldn't ever be called now unless using_lapic_timer
is false, so add a KASSERT() to that affect and remove a condition
to slightly optimize the non-lapic case.
- Change prototypeof arm_handler_execute() so that it's first arg is a
trapframe pointer rather than a void pointer for clarity.
- Use KCOUNT macro in profclock() to lookup the kernel profiling bucket.
Tested on: alpha, amd64, arm, i386, ia64, sparc64
Reviewed by: bde (mostly)
rather than embedding it in the intrframe as if_vec. This reduces diffs
with amd64 somewhat.
- Remove cf_vec from clockframe (it wasn't used anyway) and stop pushing
dummy vector arguments for ipi_bitmap_handler() and lapic_handle_timer()
since clockframe == trapframe now.
- Fix ddb to handle stack traces across interrupt entry points that just
have a trapframe on their stack and not a trapframe + vector.
- Change intr_execute_handlers() to take a trapframe rather than an
intrframe pointer.
- Change lapic_handle_intr() and atpic_handle_intr() to take a vector and
trapframe rather than an intrframe.
- GC struct intrframe now that nothing uses it anymore.
- GC CLOCK_TO_TRAPFRAME() and INTR_TO_TRAPFRAME().
Reviewed by: bde
Requested by: peter
commit to atpic.c) there may not be an IRQ 13. Instead, just keep going.
If the INT16 interface doesn't work then we will eventually panic anyway.
FWIW: We could probably just axe the support for IRQ 13 altogether at this
point. The only thing we'd lose support for are 486sx systems with
external 487 FPUs.
MFC after: 1 week
working IRQ0 with APIC anymore. Previously, it was possible to have
some other ATPIC IRQS "leak" through in a few edge cases. For example, on
my x86 test machine, ACPI re-routes the SCI (IRQ 9) to intpin 13 on the
first I/O APIC. This leaves a hole for IRQ 13 (since the APIC doesn't
provide a source for IRQ 13 in that case) with the result that the ATPIC
IRQ13 source was registered instead. This changes the 8259A drivers to
only register their interrupt sources if none of the 16 ISA IRQs have an
interrupt source already installed.
MFC after: 1 week
- Add a new SET_KERNEL_SREGS macro that sets up %ds and %es to point to
kernel data and %fs to point to per-CPU data and use the new macro
in several kernel entry points including trap and interrupt handlers.
- Convert the IPI_STOP handler Xcpustop to push a standard trap frame
rather than an application frame.
- Make the TRAP() macro private to exception.s since it is only used
there.
- Move the PCPU_*() macros in asmacros.h out of the middle of the
profiling macros.
Reviewed by: bde
Requested by: bde (4, 5)
The following repo-copies were made (by Mark Murray):
sys/i386/isa/spkr.c -> sys/dev/speaker/spkr.c
sys/i386/include/speaker.h -> sys/dev/speaker/speaker.h
share/man/man4/man4.i386/spkr.4 -> share/man/man4/spkr.4
nearly identical to wintel/ia32, with a couple of tweaks. Since it is
so similar to ia32, it is optionally added to a i386 kernel. This
port is preliminary, but seems to work well. Further improvements
will improve the interaction with syscons(4), port Linux nforce driver
and future versions of the xbox.
This supports the 64MB and 128MB boxes. You'll need the most recent
CVS version of Cromwell (the Linux BIOS for the XBOX) to boot.
Rink will be maintaining this port, and is interested in feedback.
He's setup a website http://xbox-bsd.nl to report the latest
developments.
Any silly mistakes are my fault.
Submitted by: Rink P.W. Springer rink at stack dot nl and
Ed Schouten ed at fxq dot nl
drivers I started quite some time before.
Retire the old i386-only pcf driver, and activate the new general
driver that has been sitting in the tree already for quite some
time.
Build the i2c modules for sparc64 architectures as well (where I've
been developing all this on).
and increase flexibility to allow various different approaches to be tried
in the future.
- Split struct ithd up into two pieces. struct intr_event holds the list
of interrupt handlers associated with interrupt sources.
struct intr_thread contains the data relative to an interrupt thread.
Currently we still provide a 1:1 relationship of events to threads
with the exception that events only have an associated thread if there
is at least one threaded interrupt handler attached to the event. This
means that on x86 we no longer have 4 bazillion interrupt threads with
no handlers. It also means that interrupt events with only INTR_FAST
handlers no longer have an associated thread either.
- Renamed struct intrhand to struct intr_handler to follow the struct
intr_foo naming convention. This did require renaming the powerpc
MD struct intr_handler to struct ppc_intr_handler.
- INTR_FAST no longer implies INTR_EXCL on all architectures except for
powerpc. This means that multiple INTR_FAST handlers can attach to the
same interrupt and that INTR_FAST and non-INTR_FAST handlers can attach
to the same interrupt. Sharing INTR_FAST handlers may not always be
desirable, but having sio(4) and uhci(4) fight over an IRQ isn't fun
either. Drivers can always still use INTR_EXCL to ask for an interrupt
exclusively. The way this sharing works is that when an interrupt
comes in, all the INTR_FAST handlers are executed first, and if any
threaded handlers exist, the interrupt thread is scheduled afterwards.
This type of layout also makes it possible to investigate using interrupt
filters ala OS X where the filter determines whether or not its companion
threaded handler should run.
- Aside from the INTR_FAST changes above, the impact on MD interrupt code
is mostly just 's/ithread/intr_event/'.
- A new MI ddb command 'show intrs' walks the list of interrupt events
dumping their state. It also has a '/v' verbose switch which dumps
info about all of the handlers attached to each event.
- We currently don't destroy an interrupt thread when the last threaded
handler is removed because it would suck for things like ppbus(8)'s
braindead behavior. The code is present, though, it is just under
#if 0 for now.
- Move the code to actually execute the threaded handlers for an interrrupt
event into a separate function so that ithread_loop() becomes more
readable. Previously this code was all in the middle of ithread_loop()
and indented halfway across the screen.
- Made struct intr_thread private to kern_intr.c and replaced td_ithd
with a thread private flag TDP_ITHREAD.
- In statclock, check curthread against idlethread directly rather than
curthread's proc against idlethread's proc. (Not really related to intr
changes)
Tested on: alpha, amd64, i386, sparc64
Tested on: arm, ia64 (older version of patch by cognet and marcel)
and do some preparations for handling 12x22 fonts (currently lots of code
implies and/or hardcodes a font width of 8 pixels). This will be required
on sparc64 which uses a default font size of 12x22 in order to add font
loading and saving support as well as to use a syscons(4)-supplied mouse
pointer image.
This API breakage is committed now so it can be MFC'ed in time for 6.0
and later on upcoming framebuffer drivers destined for use on sparc64
and which are expected to rely on using font loading internally and on
a syscons(4)-supplied mouse pointer image can be easily MFC'ed to
RELENG_6 rather than requiring a backport.
Tested on: i386, sparc64, make universe
MFC after: 1 week
earlier as no one has stepped up to test recent changes to the driver.
Oddly, the module was actually turned on on ia64 though I'm fairly certain
that no ia64 machine has ever had or will ever have an ISA slot.
Axe borrowed from: phk
- Add locked variants of el_init and el_start.
- Don't initialize the mutex and lock it during el_probe().
- Do initialize the mutex during attach. (el_probe() did destroy the mutex
to cleanup, so this meant the driver was always using a destroyed mutex
when it was running.)
- Setup the interrupt handler after ether_ifattach().
- Fix locking in el_detach() and el_ioctl().
Note: Since I couldn't actually find anyone with this hardware, I'm going
ahead and committing these changes so they won't be lost. I'll remove the
driver in a week (real purpose of the MFC after below) unless someone pipes
up to test this.
MFC after: 1 week
Tested by: gcc(1)
IFF_DRV_RUNNING, as well as the move from ifnet.if_flags to
ifnet.if_drv_flags. Device drivers are now responsible for
synchronizing access to these flags, as they are in if_drv_flags. This
helps prevent races between the network stack and device driver in
maintaining the interface flags field.
Many __FreeBSD__ and __FreeBSD_version checks maintained and continued;
some less so.
Reviewed by: pjd, bz
MFC after: 7 days
- Make sure timer0_max_count is set to a correct value in the lapic case.
- Revert i8254_restore() to explicitly reprogram timer 0 rather than
calling set_timer_freq() to do it. set_timer_freq() only reprograms
the counter if the max count changes which it never does on resume. This
unbreaks suspend/resume for several people.
Tested by: marks, others
Reviewed by: bde
MFC after: 3 days
copied and pasted. I had actually tested without this change in my
trees as had the other testers.
Reported by: bde, Rostislav Krasny rosti dot bsd at gmail dot com
Approved by: re (scottl)
Pointy hat to: jhb
as they are already default for I686_CPU for almost 3 years, and
CPU_DISABLE_SSE always disables it. On the other hand, CPU_ENABLE_SSE
does not work for I486_CPU and I586_CPU.
This commit has:
- Removed the option from conf/options.*
- Removed the option and comments from MD NOTES files
- Simplified the CPU_ENABLE_SSE ifdef's so they don't
deal with CPU_ENABLE_SSE from kernel configuration. (*)
For most users, this commit should be largely no-op. If you used to
place CPU_ENABLE_SSE into your kernel configuration for some reason,
it is time to remove it.
(*) The ifdef's of CPU_ENABLE_SSE are not removed at this point, since
we need to change it to !defined(CPU_DISABLE_SSE) && defined(I686_CPU),
not just !defined(CPU_DISABLE_SSE), if we really want to do so.
Discussed on: -arch
Approved by: re (scottl)
timer since irq0 isn't being driven at hz in that case and we don't need to
try to handle edge cases with rollover, etc. that require irq0 to be firing
for the timecounter to actually work.
Submitted by: phk
Tested by: schweikh
Approved by: re (scottl)
files after they were repo-copied to sys/dev/atkbdc. The sources of
atkbdc(4) and its children were moved to the new location in preparation
for adding an EBus front-end to atkbdc(4) for use on sparc64; i.e. in
order to not further scatter them over the whole tree which would have
been the result of adding atkbdc_ebus.c in e.g. sys/sparc64/ebus. Another
reason for the repo-copies was that some of the sources were misfiled,
e.g. sys/isa/atkbd_isa.c wasn't ISA-specific at all but for hanging
atkbd(4) off of atkbdc(4) and was renamed to atkbd_atkbdc.c accordingly.
Most of sys/isa/psm.c, i.e. expect for its PSMC PNP part, also isn't
ISA-specific.
- Separate the parts of atkbdc_isa.c which aren't actually ISA-specific
but are shareable between different atkbdc(4) bus front-ends into
atkbdc_subr.c (repo-copied from atkbdc_isa.c). While here use
bus_generic_rl_alloc_resource() and bus_generic_rl_release_resource()
respectively in atkbdc_isa.c instead of rolling own versions.
- Add sparc64 MD bits to atkbdc(4) and atkbd(4) and an EBus front-end for
atkbdc(4). PS/2 controllers and input devices are used on a couple of
Sun OEM boards and occur on either the EBus or the ISA bus. Depending on
the board it's either the only on-board mean to connect a keyboard and
mouse or an alternative to either RS232 or USB devices.
- Wrap the PSMC PNP part of psm.c in #ifdef DEV_ISA so it can be compiled
without isa(4) (e.g. for EBus-only machines). This ISA-specific part
isn't separated into its own source file, yet, as it requires more work
than was feasible for 6.0 in order to do it in a clean way. Actually
philip@ is working on a rewrite of psm(4) so a more comprehensive
clean-up and separation of hardware dependent and independent parts is
expected to happen after 6.0.
Tested on: i386, sparc64 (AX1105, AXe and AXi boards)
Reviewed by: philip
struct ifnet or the layer 2 common structure it was embedded in have
been replaced with a struct ifnet pointer to be filled by a call to the
new function, if_alloc(). The layer 2 common structure is also allocated
via if_alloc() based on the interface type. It is hung off the new
struct ifnet member, if_l2com.
This change removes the size of these structures from the kernel ABI and
will allow us to better manage them as interfaces come and go.
Other changes of note:
- Struct arpcom is no longer referenced in normal interface code.
Instead the Ethernet address is accessed via the IFP2ENADDR() macro.
To enforce this ac_enaddr has been renamed to _ac_enaddr.
- The second argument to ether_ifattach is now always the mac address
from driver private storage rather than sometimes being ac_enaddr.
Reviewed by: sobomax, sam
of MCOUNT to have a C version and an asm version with the same name and
not have LOCORE ifdefs to distinguish them. <machine/profile.h> provides
a C version and <machine/asmacros.h> provides an assembler version.
Discussed with: bde
i8253reg.h, and add some defines to control a speaker.
- Move PPI related defines from i386/isa/spkr.c into ppireg.h and use them.
- Move IO_{PPI,TIMER} defines into ppireg.h and timerreg.h respectively.
- Use isa/isareg.h rather than <arch>/isa/isa.h.
Tested on: i386, pc98
- Move MD files into <arch>/<arch>.
- Move bus dependent files into <arch>/<bus>.
Rename some files to more suitable names.
Repo-copied by: peter
Discussed with: imp
Instead, explicitly enable them when we setup the interrupt handler.
Also, move the setting of stathz and profhz down to the same place so
that the code flow is simpler and easier to follow.
- Don't setup an interrupt handler for IRQ0 if we are using the lapic timer
as it doesn't do anything productive in that case.
o Use IP_NPX in preference to hard coded value to write 0 to clear busy#
o Use md macro for a full reset of the npx
o Use IRQ_NPX in preference to hard coded value for each platform.
# The other two ifdefs in this file are hard to remove
rman_resource_resournce_bound wrt end parameter. The end parameter
here was the same as the start. However, it should be start + count -
1, so make it that instead.
place.
This moves the dependency on GCC's and other compiler's features into
the central sys/cdefs.h file, while the individual source files can
then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to
refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42.
By now, GCC and ICC (the Intel compiler) have been actively tested on
IA32 platforms by netchild. Extension to other compilers is supposed
to be possible, of course.
Submitted by: netchild
Reviewed by: various developers on arch@, some time ago
Also save the DAC state, increase the maximum save state size from
4k to 8k, and refuse to save the VESA state if the BIOS reports it
is larger than the maximum size we can handle.
It doesn't appear that anything currently uses this code, but it
turns out to be capable of restoring some notebook displays to a
working state after a suspend-resume cycle.
rather than forwarding interrupts from the clock devices around using IPIs:
- Add an IDT vector that pushes a clock frame and calls
lapic_handle_timer().
- Add functions to program the local APIC timer including setting the
divisor, and setting up the timer to either down a periodic countdown
or one-shot countdown.
- Add a lapic_setup_clock() function that the BSP calls from
cpu_init_clocks() to setup the local APIC timer if it is going to be
used. The setup uses a one-shot countdown to calibrate the timer. We
then program the timer on each CPU to fire at a frequency of hz * 3.
stathz is defined as freq / 23 (hz * 3 / 23), and profhz is defined as
freq / 2 (hz * 3 / 2). This gives the clocks relatively prime divisors
while keeping a low LCM for the frequency of the clock interrupts.
Thanks to Peter Jeremy for suggesting this approach.
- Remove the hardclock and statclock forwarding code including the two
associated IPIs. The bitmap IPI handler has now effectively degenerated
to just IPI_AST.
- When the local APIC timer is used we don't turn the RTC on at all, but
we still enable interrupts on the ISA timer 0 (i8254) for timecounting
purposes.
uses the i8237 without trying to emulate the PC architecture move
the register definitions for the i8237 chip into the central include
file for the chip, except for the PC98 case which is magic.
Add new isa_dmatc() function which tells us as cheaply as possible
if the terminal count has been reached for a given channel.
interrupts, read from the interrupt status register to clear any pending
interrupts. Otherwise in some rare cases the RTC would never fire any
interrupts as it constantly thinks it has an interrupt pending.
PR: i386/17800
PR: kern/76776
Submitted by: Jose M. Alcaide jose at we dot lc dot ehu dot es
MFC after: 2 weeks
instead of burying that in the atpic(4) code as atpic(4) is not the only
user of elcr(4). Change the elcr(4) code to export a global elcr_found
variable that other code can check to see if a valid ELCR was found.
MFC after: 1 month
the ISA and CBUS (called isa on pc98) attachments. Eliminate all PC98
ifdefs in the process (the driver in pc98/pc98/mse.c was a copy of the one
in i386/isa/mse.c with PC98 ifdefs). Create a module for this driver.
I've tested this my PC-9821RaS40 with moused. I've not tested this on i386
because I have no InPort cards, or similar such things. NEC standardized
on bus mice very early, long before ps/2 mice ports apeared, so all PC-98
machines supported by FreeBSD/pc98 have bus mice, I believe.
Reviewed by: nyan-san
modes on a tty structure.
Both the ".init" and the current settings are initialized allowing
the function to be used both at attach and open time.
The function takes an argument to decide if echoing should be enabled.
Echoing should not be enabled for regular physical serial ports
unless they are consoles, in which case they should be configured
by ttyconsolemode() instead.
Use the new function throughout.
and which takes a M_WAITOK/M_NOWAIT flag argument.
Add compatibility isa_dmainit() macro which whines loudly if
isa_dma_init() fails.
Problem uncovered by: tegge
pic_eoi_source() into one call. This halves the number of spinlock operations
and indirect function calls in the normal case of handling a normal (ithread)
interrupt. Optimize the atpic and ioapic drivers to use inlines where
appropriate in supporting the intr_execute_handlers() change.
This knocks 900ns, or roughly 1350 cycles, off of the time spent servicing an
interrupt in the common case on my 1.5GHz P4 uniprocessor system. SMP systems
likely won't see as much of a gain due to the ioapic being more efficient than
the atpic. I'll investigate porting this to amd64 soon.
Reviewed by: jhb
future:
rename ttyopen() -> tty_open() and ttyclose() -> tty_close().
We need the ttyopen() and ttyclose() for the new generic cdevsw
functions for tty devices in order to have consistent naming.
for unknown events.
A number of modules return EINVAL in this instance, and I have left
those alone for now and instead taught MOD_QUIESCE to accept this
as "didn't do anything".
a problem that could also be fixed differently without reverting previous
attempts to fix DELAY while the debugger is active (rev 1.204). The bug
was that the i8254 implements a countdown timer, while for (k)db_active
a countup timer was implemented. This resulted in premature termination
and consequently the breakage of DELAY. The fix (relative to rev 1.211)
is to implement a countdown timer for the kdb_active case. As such the
ability to step clock initialization is preserved and DELAY does what is
expected of it.
Blushed: bde :-)
Submitted by: bde
debugger is not active. The fixes breakages of DELAY() when
running in the debugger, because not calling getit() when the
debugger is active yields a DELAY that doesn't.
o Make debugging code conditional upon KDB instead of DDB.
o Call kdb_enter() instead of Debugger().
o Remove local (static) variable in_debugger. Use kdb_active instead.
When two drivers share an ISA DMA channel, they both call isa_dmainit()
and the second call fails if DIAGNOSTIC is on.
If isa_dmainit() was already called successfully, just return silently.
This only works if both drivers agree on the bounce buffer size,
but since sharing DMA is usually only possible on very special
hardware and then typically only for devices of the same type (which
would have multiple instances of the same device driver), this is
not a problem in practice.
belong in the respective drivers. I've not removed ALL of them, as a
few still haven't moved. I've just removed the ones that aren't used.
# these can be removed from amd64, but I'm having issues getting to
# sledge at the moment for a build.
in npxsetregs() too. npxsetregs() must overwrite the previous state, and
it is never paired with an npxgetregs() that would defuse the previous
state (since npxgetregs() would have fninit'ed the state, leaving nothing
to do).
PR: 68058 (this should complete the fix)
Tested by: Simon Barner <barner@in.tum.de>
frstor can trap despite it being a control instruction, since it bogusly
checks for pending exceptions in the state that it is overwriting.
This used to be a non-problem because frstor was always paired with a
previous fnsave, and fnsave does an implicit fninit so any pending
exceptions only remain live in the saved state. Now frstor is sometimes
paired with npxdrop() and we must do a little more than just forget
that the npx was used in npxdrop() to avoid a trap later. This is a
non-problem in the FXSR case because fxrstor doesn't do the bogus check.
FXSR is part of SSE, and npxdrop() is only in FreeBSD-5.x, so this bug
only affected old machines running FreeBSD-5.x.
PR: 68058
Dividing by 0 in order to check for irq13/exception16 delivery apparently
always causes an irq13 even if we have configured for exception16 (by
setting CR0_NE). This was expected, but the timing of the irq13 was
unexpected. Without CR0_NE, the irq13 is delivered synchronously at
least on my test machine, but with CR0_NE it is delivered a little
later (about 250 nsec) in PIC mode and much later (5000-10000 nsec)
in APIC mode. So especially in APIC mode, the irq13 may arrive after
it is supposed to be shut down. It should then be masked, but the
shutdown is incomplete, so the irq goes to a null handler that just
reports it as stray. The fix is to wait a bit after dividing by 0 to
give a good chance of the irq13 being handled by its proper handler.
Removed the hack that was supposed to recover from the incomplete shutdown
of irq13. The shutdown is now even more incomplete, or perhaps just
incomplete in a different way, but the hack now has no effect because
irq13 is edge triggered and handling of edge triggered interrupts is
now optimized by skipping their masking. The hack only worked due
to it accidentally not losing races.
The incomplete shutdown of irq13 still allows unprivileged users to
generate a stray irq13 (except on systems where irq13 is actually used)
by unmasking an npx exception and causing one. The exception gets
handled properly by the exception 16 handler. A spurious irq13 is
delivered asynchronously but is harmless (as in the probe) because it
is almost perfectly not handled by the null interrupt handler.
Perfectly not handling it involves mainly not resetting the npx busy
latch. This prevents further irq13's despite them not being masked in
the [A]PIC.
