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.
gmon and struct gmonhdr was originally just to represent the kernel
(profiling) clock frequency and it remains poorly suited to representing
the frequencies of fast counters like the TSC. It broke a year or two
ago. This quick fix keeps it working for another year or month or two
until TSC frequencies can exceed 2^32, by dividing the frequency by 2.
Dividing the frequency by 4 would work for a little longer but would
lose a little too much precision.
Fixed profiling of trap, syscall and interrupt handlers and some
ordinary functions, essentially by backing out half of rev.1.106 of
i386/exception.s. The handlers must be between certain labels for
the purposes of profiling, and this was broken by scattering them in
separately compiled .s files, especially for ordinary functions that
ended up between the labels. Merge the files by #including them as
before, except with different pathnames and better comments and
organization. Changes to the scattered files are minimal -- just
move the labels to the file that does the #includes.
This also partly fixes profiling of IPIs -- all IPI handlers are now
correctly classified as interrupt handlers, but many are still missing
mcount calls.
vm86bios.s is included as before, but it is now between the labels for
interrupt handlers again, which seems to be wrong since half of it is
for a non-interrupt handler.
are used.
- Reduce duplication of a couple of macros removing the duplicates from
ich.h.
- Remove unused macros from icu.h as well as locore protection as this
header is no longer included in assembly sources.
polarity for a specified IRQ. The intr_config_intr() function wraps
this pic method hiding the IRQ to interrupt source lookup.
- Add a config_intr() method to the atpic(4) driver that reconfigures
the interrupt using the ELCR if possible and returns an error otherwise.
- Add a config_intr() method to the apic(4) driver that just logs any
requests that would change the existing programming under bootverbose.
Currently, the only changes the apic(4) driver receives are due to bugs
in the acpi(4) driver and its handling of link devices, hence the reason
for such requests currently being ignored.
- Have the nexus(4) driver on i386 implement the bus_config_intr() function
by calling intr_config_intr().
IRQ is edge triggered or level triggered. For ISA interrupts, we assume
that edge triggered interrupts are always active high and that level
triggered interrupts are always active low.
- Don't disable an edge triggered interrupt in the PIC. This avoids
outb instructions to the actual PIC for traditional ISA IRQs such as
IRQ 1, 6, 14, and 15. (Fast interrupts such as IRQs 0 and 8 don't mask
their source, so this doesn't change anything for them.)
- For MCA systems we assume that all interrupts are level triggered and
thus need masking. Otherwise, we probe the ELCR. If it exists we trust
what it tells us regarding which interrupts are level triggered. If it
does not exist, we assume that IRQs 0, 1, 2, and 8 are edge triggered
and that all other IRQs are level triggered and need masking.
- Instruct the ELCR mini-driver to restore its saved state during resume.
register controlled the trigger mode and polarity of EISA interrupts.
However, it appears that most (all?) PCI systems use the ELCR to manage
the trigger mode and polarity of ISA interrupts as well since ISA IRQs used
to route PCI interrupts need to be level triggered with active low
polarity. We check to see if the ELCR exists by sanity checking the value
we get back ensuring that IRQS 0 (8254), 1 (atkbd), 2 (the link from the
slave PIC), and 8 (RTC) are all clear indicating edge trigger and active
high polarity.
This mini-driver will be used by the atpic driver to manage the trigger and
polarity of ISA IRQs. Also, the mptable parsing code will use this mini
driver rather than examining the ELCR directly.
