- Split the intr_table_lock into an sx lock used for most things, and a
spin lock to protect intrcnt_index. Originally I had this as a spin lock
so interrupt code could use it to lookup sources. However, we don't
actually do that because it would add a lot of overhead to interrupts,
and if we ever do support removing interrupt sources, we can use other
means to safely do so w/o locking in the interrupt handling code.
- Replace is_enabled (boolean) with is_handlers (a count of handlers) to
determine if a source is enabled or not. This allows us to notice when
a source is no longer in use. When that happens, we now invoke a new
PIC method (pic_disable_intr()) to inform the PIC driver that the
source is no longer in use. The I/O APIC driver frees the APIC IDT
vector when this happens. The MSI driver no longer needs to have a
hack to clear is_enabled during msi_alloc() and msix_alloc() as a result
of this change as well.
- Add an apic_disable_vector() to reset an IDT vector back to Xrsvd to
complement apic_enable_vector() and use it in the I/O APIC and MSI code
when freeing an IDT vector.
- Add a new nexus hook: nexus_add_irq() to ask the nexus driver to add an
IRQ to its irq_rman. The MSI code uses this when it creates new
interrupt sources to let the nexus know about newly valid IRQs.
Previously the msi_alloc() and msix_alloc() passed some extra stuff
back to the nexus methods which then added the IRQs. This approach is
a bit cleaner.
- Change the MSI sx lock to a mutex. If we need to create new sources,
drop the lock, create the required number of sources, then get the lock
and try the allocation again.
as if they were really passed by reference. Specifically, the dead stores
elimination pass in the GCC 4.1 optimiser breaks the non-compliant behavior
on which FreeBSD relied. This change brings FreeBSD up to date by switching
trap frames to being explicitly passed by reference.
Reviewed by: kan
Tested by: kan
(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
- 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
- Move PUSH_FRAME and POP_FRAME to asmacros.h and use PUSH_FRAME in
atpic entry points.
- Move PCPU_* asm macros out of the middle of the asm profiling macros.
- Pass IRQ vector argument as an int rather than void * to reduce diffs
with i386.
- EOI the lapic in C for the lapic timer handler.
- GC unused Xcpuast function.
- Split IPI_STOP handling code of ipi_nmi_handler() out into a
cpustop_handler() function and call it from Xcpustop rather than
duplicating all the logic in assembly.
- Fixup the list of symbols with interrupt frames in ddb traces.
Xatpic_fastintr* have never existed on amd64, and the lapic timer
handler and various IPI handlers were missing.
- Use trapframe instead of intrframe for interrupt entry points (on amd64
the interrupt vector was already a separate argument, so the two frames
were already identical) and GC intrframe.
Submitted by: peter (3)
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
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)
- This is heavily derived from John Baldwin's apic/pci cleanup on i386.
- I have completely rewritten or drastically cleaned up some other parts.
(in particular, bootstrap)
- This is still a WIP. It seems that there are some highly bogus bioses
on nVidia nForce3-150 boards. I can't stress how broken these boards
are. I have a workaround in mind, but right now the Asus SK8N is broken.
The Gigabyte K8NPro (nVidia based) is also mind-numbingly hosed.
- Most of my testing has been with SCHED_ULE. SCHED_4BSD works.
- the apic and acpi components are 'standard'.
- If you have an nVidia nForce3-150 board, you are stuck with 'device
atpic' in addition, because they somehow managed to forget to connect the
8254 timer to the apic, even though its in the same silicon! ARGH!
This directly violates the ACPI spec.
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().
