Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

etire the cpumask_t type and replace it with cpuset_t usage.

This is intended to fix the bug where cpu mask objects are
capped to 32. MAXCPU, then, can now arbitrarely bumped to whatever
value. Anyway, as long as several structures in the kernel are
statically allocated and sized as MAXCPU, it is suggested to keep it
as low as possible for the time being.

Technical notes on this commit itself:
- More functions to handle with cpuset_t objects are introduced.
The most notable are cpusetobj_ffs() (which calculates a ffs(3)
for a cpuset_t object), cpusetobj_strprint() (which prepares a string
representing a cpuset_t object) and cpusetobj_strscan() (which
creates a valid cpuset_t starting from a string representation).
- pc_cpumask and pc_other_cpus are target to be removed soon.
With the moving from cpumask_t to cpuset_t they are now inefficient
and not really useful. Anyway, for the time being, please note that
access to pcpu datas is protected by sched_pin() in order to avoid
migrating the CPU while reading more than one (possible) word
- Please note that size of cpuset_t objects may differ between kernel
and userland. While this is not directly related to the patch itself,
it is good to understand that concept and possibly use the patch
as a reference on how to deal with cpuset_t objects in userland, when
accessing kernland members.
- KTR_CPUMASK is changed and now is represented through a string, to be
set as the example reported in NOTES.

Please additively note that no MAXCPU is bumped in this patch, but
private testing has been done until to MAXCPU=128 on a real 8x8x2(htt)
machine (amd64).

Please note that the FreeBSD version is not yet bumped because of
the upcoming pcpu changes. However, note that this patch is not
targeted for MFC.

People to thank for the time spent on this patch:
- sbruno, pluknet and Nicholas Esborn (nick AT desert DOT net) tested
several revision of the patches and really helped in improving
stability of this work.
- marius fixed several bugs in the sparc64 implementation and reviewed
patches related to ktr.
- jeff and jhb discussed the basic approach followed.
- kib and marcel made targeted review on some specific part of the
patch.
- marius, art, nwhitehorn and andreast reviewed MD specific part of
the patch.
- marius, andreast, gonzo, nwhitehorn and jceel tested MD specific
implementations of the patch.
- Other people have made contributions on other patches that have been
already committed and have been listed separately.

Companies that should be mentioned for having participated at several
degrees:
- Yahoo! for having offered the machines used for testing on big
count of CPUs.
- The FreeBSD Foundation for having sponsored my devsummit attendance,
which has been instrumental.
- Sandvine for having offered offices and infrastructure during
development.

(I really hope I didn't forget anyone, if it happened I apologize in
advance).

Fix the interrupt code, broken 7 months ago. The interrupt framework
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

Configure interrupts on SMP systems to be distributed among all online
CPUs by default, and provide a functional version of BUS_BIND_INTR().
While here, fix some potential concurrency problems in the interrupt
handling code.

Provide for multiple, cascaded PICs on PowerPC systems, and extend the
OFW interrupt map interface to also return the device's interrupt parent.

MFC after: 8.1-RELEASE

Add support for the BUS_CONFIG_INTR() method to the platform and to
openpic(4). Make use of it in ocpbus(4). On the MPC85xxCDS, IRQ0:4
are active-low.

Add PIC support for IPIs. When registering an interrupt handler,
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.

Revamp the interrupt handling in support of INTR_FILTER. This includes:
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)

Update openpic to support the new bus_setup_intr() syntax.

Reviewed by: marcel

/* -> /*- for license, minor formatting changes

Add interrupt handling support code.

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.