- Copy stable/10 (r259064) to releng/10.0 as part of the
10.0-RELEASE cycle.
- Update __FreeBSD_version [1]
- Set branch name to -RC1

[1] 10.0-CURRENT __FreeBSD_version value ended at '55', so
start releng/10.0 at '100' so the branch is started with
a value ending in zero.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Add locking to ppc and ppbus and mark the whole lot MPSAFE:
- To avoid having a bunch of locks that end up always getting acquired as
a group, give each ppc(4) device a mutex which it shares with all the
child devices including ppbus(4), lpt(4), plip(4), etc. This mutex
is then used for all the locking.
- Rework the interrupt handling stuff yet again. Now ppbus drivers setup
their interrupt handler during attach and tear it down during detach
like most other drivers. ppbus(4) only invokes the interrupt handler
of the device that currently owns the bus (if any) when an interrupt
occurs, however. Also, interrupt handlers in general now accept their
softc pointers as their argument rather than the device_t. Another
feature of the ppbus interrupt handlers is that they are called with
the parent ppc device's lock already held. This minimizes the number
of lock operations during an interrupt.
- Mark plip(4), lpt(4), pcfclock(4), ppi(4), vpo(4) MPSAFE.
- lpbb(4) uses the ppc lock instead of Giant.
- Other plip(4) changes:
- Add a mutex to protect the global tables in plip(4) and free them on
module unload.
- Add a detach routine.
- Split out the init/stop code from the ioctl routine into separate
functions.
- Other lpt(4) changes:
- Use device_printf().
- Use a dedicated callout for the lptout timer.
- Allocate the I/O buffers at attach and detach rather than during
open and close as this simplifies the locking at the cost of
1024+32 bytes when the driver is attached.
- Other ppi(4) changes:
- Use an sx lock to serialize open and close.
- Remove unused HADBUS flag.
- Add a detach routine.
- Use a malloc'd buffer for each read and write to avoid races with
concurrent read/write.
- Other pps(4) changes:
- Use a callout rather than a callout handle with timeout().
- Conform to the new ppbus requirements (regular mutex, non-filter
interrupt handler). pps(4) is probably going to have to become a
standalone driver that doesn't use ppbus(4) to satisfy it's
requirements for low latency as a result.
- Use an sx lock to serialize open and close.
- Other vpo(4) changes:
- Use the parent ppc device's lock to create the CAM sim instead of
Giant.
- Other ppc(4) changes:
- Fix ppc_isa's detach method to detach instead of calling attach.

Tested by: no one :-(

Various whitespace and style fixes.

Rework the handling of interrupt handlers for children of ppc and ppbus:
- Retire IVARs for passing IRQs around. Instead, ppbus and ppc now allow
child devices to access the interrupt by via a rid 0 IRQ resource
using bus_alloc_resource_any().
- ppc creates its own interrupt event to manage the interrupt handlers of
child devices. ppc does not allow child devices to use filters. It
could allow this if needed, but none of the current drivers use them
and it adds a good bit of complication. It uses
intr_event_execute_handlers() to fire the child device interrupt handlers
from its threaded interrupt handler.
- Remove the ppbus_dummy_intr() hack. Now the ppc device always has an
interrupt handler registered and we no longer bounce all the way up to
nexus to manage adding/removing ppbus child interrupt handlers. Instead,
the child handlers are added and removed to the private interrupt event
in the ppc device.

Use ppc_detach() for device_detach instead of ppc_attach().

MFC after: 1 week

o Move ISA specific code from ppc.c to ppc_isa.c -- a bus front-
end for isa(4).
o Add a seperate bus frontend for acpi(4) and allow ISA DMA for
it when ISA is configured in the kernel. This allows acpi(4)
attachments in non-ISA configurations, as is possible for ia64.
o Add a seperate bus frontend for pci(4) and detect known single
port parallel cards.
o Merge PC98 specific changes under pc98/cbus into the MI driver.
The changes are minor enough for conditional compilation and
in this form invites better abstraction.
o Have ppc(4) usabled on all platforms, now that ISA specifics
are untangled enough.