Approved by:	re (hrs, kensmith)

Do not try to call keyboard callback unless keyboard is active and busy.
This should fix 'kbdcontrol -K < /dev/console' panic on sparc64 with sunkbd(4).

PR:		sparc64/96798
Approved by:	re (hrs)

associated changes.  More details below:

  Remove public declarations of variables that were forgotten when they were
  made static.

  Revision  Changes    Path
  1.31      +0 -1      src/sys/sys/interrupt.h

  Make sure the interrupt is masked before processing it, or bad things
  can happen.

  Revision  Changes    Path
  1.10      +3 -3      src/sys/arm/arm/intr.c

  Reorganize the interrupt handling code a bit to make a few things cleaner
  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)

  Revision  Changes    Path
  1.88      +43 -29    src/sys/alpha/alpha/interrupt.c
  1.38      +5 -5      src/sys/alpha/isa/isa.c
  1.16      +58 -52    src/sys/amd64/amd64/intr_machdep.c
  1.6       +1 -1      src/sys/amd64/include/intr_machdep.h
  1.16      +2 -2      src/sys/amd64/isa/atpic.c
  1.11      +28 -22    src/sys/arm/arm/intr.c
  1.462     +2 -2      src/sys/dev/sio/sio.c
  1.6       +1 -1      src/sys/dev/uart/uart_kbd_sun.c
  1.24      +2 -2      src/sys/dev/uart/uart_tty.c
  1.15      +58 -52    src/sys/i386/i386/intr_machdep.c
  1.8       +1 -1      src/sys/i386/include/intr_machdep.h
  1.21      +2 -2      src/sys/i386/isa/atpic.c
  1.52      +32 -25    src/sys/ia64/ia64/interrupt.c
  1.180     +3 -2      src/sys/kern/kern_clock.c
  1.127     +437 -270  src/sys/kern/kern_intr.c
  1.206     +0 -1      src/sys/kern/subr_witness.c
  1.6       +3 -3      src/sys/powerpc/include/intr_machdep.h
  1.7       +35 -32    src/sys/powerpc/powerpc/intr_machdep.c
  1.14      +1 -1      src/sys/sparc64/include/intr_machdep.h
  1.24      +43 -36    src/sys/sparc64/sparc64/intr_machdep.c
  1.32      +36 -36    src/sys/sys/interrupt.h
  1.440     +1 -3      src/sys/sys/proc.h

  Catch up with interrupt-thread changes.

  Revision  Changes    Path
  1.32      +1 -1      src/sys/dev/zs/zs.c

  Catch up with new interrupt handling code.

  Revision  Changes    Path
  1.16      +3 -3      src/sys/netgraph/bluetooth/drivers/bt3c/ng_bt3c_pccard.c

  Catch up with new interrupt handling code.

  Revision  Changes    Path
  1.162     +2 -2      src/sys/dev/cy/cy.c
  1.101     +2 -2      src/sys/dev/rc/rc.c

  Catch up with new interrupt handling code.

  Revision  Changes    Path
  1.50      +2 -2      src/sys/dev/cx/if_cx.c
  1.41      +1 -1      src/sys/dev/sab/sab.c
  1.238     +2 -2      src/sys/pc98/cbus/sio.c

  Add a swi_remove() function to teardown software interrupt handlers.  For
  now it just calls intr_event_remove_handler(), but at some point it might
  also be responsible for tearing down interrupt events created via swi_add.

  Revision  Changes    Path
  1.128     +17 -0     src/sys/kern/kern_intr.c
  1.33      +1 -0      src/sys/sys/interrupt.h

  - Use swi_remove() to teardown swi handlers rather than
    intr_event_remove_handler().
  - Remove tty: prefix from a couple of swi handler names.

  Revision  Changes    Path
  1.51      +1 -1      src/sys/dev/cx/if_cx.c
  1.102     +2 -2      src/sys/dev/rc/rc.c
  1.42      +1 -1      src/sys/dev/sab/sab.c
  1.25      +1 -1      src/sys/dev/uart/uart_tty.c
  1.33      +1 -1      src/sys/dev/zs/zs.c
  1.17      +2 -2      src/sys/netgraph/bluetooth/drivers/bt3c/ng_bt3c_pccard.c

  Remove a stray return statement in the interrupt dispatch function
  that caused a premature exit after calling a fast interrupt handler
  and bypassing a much needed critical_exit() and the scheduling of
  the interrupt thread for non-fast handlers. In short: unbreak :-)

  Revision  Changes    Path
  1.53      +0 -1      src/sys/ia64/ia64/interrupt.c

  If we get a stray interrupt, return after logging it.  In the extremely
  rare case of a stray interrupt to an unregistered source (such as a stray
  interrupt from the 8259As when using APIC), this could result in a page
  fault when it tried to walk the list of interrupt handlers to execute
  INTR_FAST handlers.  This bug was introduced with the intr_event changes,
  so it's not present in 5.x or 6.x.

  Submitted by:   Mark Tinguely tinguely at casselton dot net

  Revision  Changes    Path
  1.17      +1 -0      src/sys/amd64/amd64/intr_machdep.c
  1.16      +1 -0      src/sys/i386/i386/intr_machdep.c

Approved by:	re (scottl)

times which was added in the last revision with what should be a proper
solution as long as keyboards that were pluggged in after the kernel
has fully booted aren't supported. I.e. when sunkbd_configure() is
called for the high-level console probe make sure that the keyboard is
both successfully configured (i.e. also probed) and attached. The band-
aid left the possibility to attach the keyboard device to the high-level
console without attaching the keyboard device itself when the keyboard
is plugged in after uart(4) attached but before syscons(4) does.

  a band-aid allowing to call this function savely multiple times, e.g.
  during sckbdprobe() and sc_probe_unit(). Otherwise calling it a second
  time results in a non-working keyboard. This needs a lot of more work
  to actually do the right thing and work like expected.
- Let sunkbd_configure() return the number of the found keyboards, i.e.
  1 in case probing succeeds, as it's expected. The return values of the
  keyboard configure functions however currently aren't checked so this
  doesn't make a difference at the moment.
- Use FBSDID.

The presence or absence of a keyboard does not change whether an
UART is designed as a keyboard port or not and thus whether we
can use the port as a TTY or not.
We now call sunkbd_attach() even when we didn't previously find
a keyboard. Emit a useful message stating that no keyboard was
found, but don't do anything else.

MFC after: 5 days

is only defined in that case.

this will work with any uart backend, currently supported hardware uses
either ns8250 or z8530.