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
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.
interrupt source.
- Only do an outb() to the PIC to clear a bit in imen if the bit is set.
- Add a NUM_ISA_IRQS macro to replace uglier
'sizeof(array) / sizeof(member)' expressions along with a CTASSERT() to
ensure that the macro is correct.
source count pointers at them so that intr_execute_handlers() won't
choke when it tries to handle an unregisterd ATPIC interrupt source.
- Install the low-level ATPIC interrupt handlers when we first program the
ATPIC in atpic_startup() rather than at SI_SUB_INTR. This is only
necessary to work around buggy code that enables interrupts too early
in the boot process (namely, the vm86 code).
Approved by: re (rwatson)
longer uses these interrupt vectors for its ISA interrupt pins, so these
entries will not be overwritten. If we get a spurious interrupt from the
ATPIC when using the APIC, it will be treated as a stray interrupt instead
of causing a panic.
vector stubs and into the C functions they call.
- Move disabling and EOIing of interrupt sources out of PIC driver entry
points and into intr_execute_handlers(). Intr_execute_handlers() only
disables a source for an interrupt if it is a stray interrupt or has
threaded handlers. Sources with fast handlers no longer disable (mask)
the source while executing the handlers.
- Move the setting of clkintr_pending into intr_execute_handlers() and set
the variable for any interrupt source with a vector of 0. (Should only
be true for IRQ 0.) This fixes clkintr_pending in the NO_MIXED_MODE
case.
- Implement lapic_eoi() and use it to implement ioapic_eoi_source().
- Rename atpic_sched_ithd() to atpic_handle_intr() since it is used to
handle all atpic interrupts and not just threaded ones.
Inspired by: peter's changes to amd64 in p4 (1)
Requested by: bde (2)
default we provide 16 interrupt sources for IRQs 0 through 15. However,
if the I/O APIC driver has already registered sources for any of those IRQs
then we will silently fail to register our own source for that IRQ.
Note that i386/isa/icu.h is now specific to the 8259A and no longer
contains any info relevant to APICs. Also note that fast interrupts no
longer use a separate entry point. Instead, both fast and threaded
interrupts share the same entry point which merely looks up the appropriate
source and passes control to intr_execute_handlers().
