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
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
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().
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.
- Move the IPI and local APIC interrupt vectors up into the 0xf0 - 0xff
range. The pmap lazyfix IPI was reordered down next to the TLB
shootdowns to avoid conflicting with the spurious interrupt vector.
- Move the base of APIC interrupts up 16 so that the first 16 APIC
interrupts do not overlap the vectors used by the ATPIC.
- Remove bogus interrupt vector reservations for LINT[01].
- Now that 0xc0 - 0xef are available, use them for device interrupts.
This increases the number of APIC device interrupts to 191.
- Increase the system-wide number of global interrupts to 191 to catch up
to more APIC interrupts.
Requested by: peter (2)
that provides methods via a PIC driver to do things like mask a source,
unmask a source, enable it when the first interrupt handler is added, etc.
The interrupt code provides a table of interrupt sources indexed by IRQ
numbers, or vectors. These vectors are what new-bus uses for its IRQ
resources and for bus_setup_intr()/bus_teardown_intr(). The interrupt
code then maps that vector a given interrupt source object. When an
interrupt comes in, the low-level interrupt code looks up the interrupt
source for the source that triggered the interrupt and hands it off to
this code to execute the appropriate handlers.
By having an interrupt source abstraction, this allows us to have different
types of interrupt source providers within the shared IRQ address space.
For example, IRQ 0 may map to pin 0 of the master 8259A PIC, IRQs 1
through 60 may map to pins on various I/O APICs, and IRQs 120 through
128 may map to MSI interrupts for various PCI devices.
