already supported nested PICs, but was limited to having a nested
AT-PIC only. With G5 support the need for nested OpenPIC controllers
needed to be added. This was done the wrong way and broke the MPC8555
eval system in the process.
OFW, as well as FDT, describe the interrupt routing in terms of a
controller and an interrupt pin on it. This needs to be mapped to a
flat and global resource: the IRQ. The IRQ is the same as the PCI
intline and as such needs to be representable in 8 bits. Secondly,
ISA support pretty much dictates that IRQ 0-15 should be reserved
for ISA interrupts, because of the internal workins of south bridges.
Both were broken.
This change reverts revision 209298 for a big part and re-implements
it simpler. In particular:
o The id() method of the PIC I/F is removed again. It's not needed.
o The openpic_attach() function has been changed to take the OFW
or FDT phandle of the controller as a second argument. All bus
attachments that previously used openpic_attach() as the attach
method of the device I/F now implement as bus-specific method
and pass the phandle_t to the renamed openpic_attach().
o Change powerpc_register_pic() to take a few more arguments. In
particular:
- Pass the number of IPIs specificly. The number of IRQs carved
out for a PIC is the sum of the number of int. pins and IPIs.
- Pass a flag indicating whether the PIC is an AT-PIC or not.
This tells the interrupt framework whether to assign IRQ 0-15
or some other range.
o Until we implement proper multi-pass bus enumeration, we have to
handle the case where we need to map from PIC+pin to IRQ *before*
the PIC gets registered. This is done in a similar way as before,
but rather than carving out 256 IRQs per PIC, we carve out 128
IRQs (124 pins + 4 IPIs). This is supposed to handle the G5 case,
but should really be fixed properly using multiple passes.
o Have the interrupt framework set root_pic in most cases and not
put that burden in PIC drivers (for the most part).
o Remove powerpc_ign_lookup() and replace it with powerpc_get_irq().
Remove IGN_SHIFT, INTR_INTLINE and INTR_IGN.
Related to the above, fix the Freescale PCI controller driver, broken
by the FDT code. Besides not attaching properly, bus numbers were
assigned improperly and enumeration was broken in general. This
prevented the AT PIC from being discovered and interrupt routing to
work properly. Consequently, the ata(4) controller stopped functioning.
Fix the driver, and FDT PCI support, enough to get the MPC8555CDS
going again. The FDT PCI code needs a whole lot more work.
No breakages are expected, but lackiong G5 hardware, it's possible
that there are unpleasant side-effects. At least MPC85xx support is
back to where it was 7 months ago -- it's amazing how badly support
can be broken in just 7 months...
Sponsored by: Juniper Networks
CPUs by default, and provide a functional version of BUS_BIND_INTR().
While here, fix some potential concurrency problems in the interrupt
handling code.
Powermac G5 systems. MSI and several other things are not presently
supported.
The U3/U4 internal device support portions of this change were contributed
by Andreas Tobler.
MFC after: 1 week
controller in the VIA southbridge functional in the CDS
(Configurable Development System) for MPC85XX.
The embedded USB controllers look operational but the
interrupt steering is still wrong.
the PIC also informs the platform at which IRQ level it can start
assigning IPIs, since this can depend on the number of IRQs
supported for external interrupts.
o Revamp the PIC I/F to only abstract the PIC hardware. The
resource handling has been moved to nexus, where it belongs.
o Include EOI and MASK+EOI methods to the PIC I/F in support of
INTR_FILTER.
o With the allocation of interrupt resources and setup of
interrupt handlers in the common platform code we can delay
talking to the PIC hardware after enumeration of all devices.
Introduce a call to powerpc_intr_enable() in configure_final()
to achieve that and have powerpc_setup_intr() only program the
PIC when !cold.
o As a consequence of the above, remove all early_attach() glue
from the OpenPIC and Heathrow PIC drivers and have them
register themselves when they're found during enumeration.
o Decouple the interrupt vector from the interrupt request line.
Allocate vectors increasingly so that they can be used for
the intrcnt index as well. Extend the Heathrow PIC driver to
translate between IRQ and vector. The OpenPIC driver already
has the support for vectors in hardware.
Approved by: re (blanket)
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)
I've tried to make this fairly platform-independant as some PowerPC platforms
may not have openpic-style interrupt controllers. This may not have the best
performance but it works for now.
