Changes to make MPSAFE interrupts work on Alpha:

- Remove the ipl argument to scb_set() and the associated array of
"mpsafe" booleans initialized based on the ipl. It was bogus
anyway; all IPL_{BIO,NET,TTY}, etc. values are aliases of IPL_VM,
and for all practical purposes, there is really only one device
interrrupt level on Alpha anyway. Intead, we now treat all dispatches
from the SCB vector table as MP-safe, and it is now the handler for
that vector who is responsible for acquiring the KERNEL_LOCK if needed.

- Update the direct interrupt vector handlers in jensenio and TURBOchannel
to acquire the KERNEL_LOCK.

- Introduce a new ALPHA_INTR_MPSAFE flag, and add a flags argument to
alpha_shared_intr_establish(). When it is set, indicate that the
handler is MP-safe. Update alpha_shared_intr_dispatch() to pay
attention and acquire the KERNEL_LOCK (or not) as indicated.

- Re-factor all of the PCI interrupt handling, providing "generic PCI"
"PCI interrupts through ISA IRQs" implementations to significantly
reduce code duplication. Supplement the PCI chipset tag with more
info to facilitate this, and make the PCI interrupt-related routines
take a pci_chipset_tag_t argument rather than a void * argument.

- Because PCI interrupts on KN8AE are dispatched directly from the
SCB, provide a wrapper for non-MPSAFE interrupt handlers that
acquires the KERNEL_LOCK.

- Change the pci_intr_handle_t type to be a struct rather than an
integer type in order to catch any direct use of it as a value.
Add a set of functions to interact with pci_intr_handle_t, including
setting interrupt flags.

- Implement pci_intr_setattr() so that the PCI_INTR_MPSAFE attribute
can be set on a pci_intr_handle_t.

- While I'm here, make all of the MI PCI back-end operations call
through real functions rather than hopping directly through function
pointers in the chipset tag.

This change looks a lot bigger than it really is because of the re-factor
in the plethora of model-specific PCI interrupt back-ends. The KN8AE,
KN300, and T2/T3/T4 (Sable) are largely un-changed.

Neither pci_dma64_available(), pci_probe_device(), pci_mapreg_map(9),
pci_find_rom(), pci_intr_map(9), pci_enumerate_bus(), nor the match
predicate passed to pciide_compat_intr_establish() should ever modify
their pci_attach_args argument, so make their pci_attach_args arguments
const and deal with the fallout throughout the kernel.

For the most part, these changes add a 'const' where there was no
'const' before, however, some drivers and MD code used to modify
pci_attach_args. Now those drivers either copy their pci_attach_args
and modify the copy, or refrain from modifying pci_attach_args:

Xen: according to Manuel Bouyer, writing to pci_attach_args in
pci_intr_map() was a leftover from Xen 2. Probably a bug. I
stopped writing it. I have not tested this change.

siside(4): sis_hostbr_match() needlessly wrote to pci_attach_args.
Probably a bug. I use a temporary variable. I have not tested this
change.

slide(4): sl82c105_chip_map() overwrote the caller's pci_attach_args.
Probably a bug. Use a local pci_attach_args. I have not tested
this change.

viaide(4): via_sata_chip_map() and via_sata_chip_map_new() overwrote the
caller's pci_attach_args. Probably a bug. Make a local copy of the
caller's pci_attach_args and modify the copy. I have not tested
this change.

While I'm here, make pci_mapreg_submap() static.

With these changes in place, I have tested the compilation of these
kernels:

alpha GENERIC
amd64 GENERIC XEN3_DOM0
arc GENERIC
atari HADES MILAN-PCIIDE
bebox GENERIC
cats GENERIC
cobalt GENERIC
evbarm-eb NSLU2
evbarm-el ADI_BRH ARMADILLO9 CP3100 GEMINI GEMINI_MASTER GEMINI_SLAVE GUMSTIX
HDL_G IMX31LITE INTEGRATOR IQ31244 IQ80310 IQ80321 IXDP425 IXM1200
KUROBOX_PRO LUBBOCK MARVELL_NAS NAPPI SHEEVAPLUG SMDK2800 TEAMASA_NPWR
TEAMASA_NPWR_FC TS7200 TWINTAIL ZAO425
evbmips-el AP30 DBAU1500 DBAU1550 MALTA MERAKI MTX-1 OMSAL400 RB153 WGT624V3
evbmips64-el XLSATX
evbppc EV64260 MPC8536DS MPC8548CDS OPENBLOCKS200 OPENBLOCKS266
OPENBLOCKS266_OPT P2020RDB PMPPC RB800 WALNUT
hp700 GENERIC
i386 ALL XEN3_DOM0 XEN3_DOMU
ibmnws GENERIC
macppc GENERIC
mvmeppc GENERIC
netwinder GENERIC
ofppc GENERIC
prep GENERIC
sandpoint GENERIC
sgimips GENERIC32_IP2x
sparc GENERIC_SUN4U KRUPS
sparc64 GENERIC

As of Sun Apr 3 15:26:26 CDT 2011, I could not compile these kernels
with or without my patches in place:

### evbmips-el GDIUM

nbmake: nbmake: don't know how to make /home/dyoung/pristine-nbsd/src/sys/arch/mips/mips/softintr.c. Stop

### evbarm-el MPCSA_GENERIC
src/sys/arch/evbarm/conf/MPCSA_GENERIC:318: ds1672rtc*: unknown device `ds1672rtc'

### ia64 GENERIC

/tmp/genassym.28085/assym.c: In function 'f111':
/tmp/genassym.28085/assym.c:67: error: invalid application of 'sizeof' to incomplete type 'struct pcb'
/tmp/genassym.28085/assym.c:76: error: dereferencing pointer to incomplete type

### sgimips GENERIC32_IP3x

crmfb.o: In function `crmfb_attach':
crmfb.c:(.text+0x2304): undefined reference to `ddc_read_edid'
crmfb.c:(.text+0x2304): relocation truncated to fit: R_MIPS_26 against `ddc_read_edid'
crmfb.c:(.text+0x234c): undefined reference to `edid_parse'
crmfb.c:(.text+0x234c): relocation truncated to fit: R_MIPS_26 against `edid_parse'
crmfb.c:(.text+0x2354): undefined reference to `edid_print'
crmfb.c:(.text+0x2354): relocation truncated to fit: R_MIPS_26 against `edid_print'

branches: 1.4.4; 1.4.6;
ANSIfy functions with function-pointer arguments

Remove all the __P() from sys (excluding sys/dist)
Diff checked with grep and MK1 eyeball.
i386 and amd64 GENERIC and sys still build.

branches: 1.2.154; 1.2.162; 1.2.168;
Fix a typo.

Machine-dependent bits for PCI IDE. This redirects PCI IDE compat interrupt
goop to the appropriate platform-dependent code.