all pools have their ipl set via pool_setipl, so fold it into pool_init.

the ioff argument to pool_init() is unused and has been for many
years, so this replaces it with an ipl argument. because the ipl
will be set on init we no longer need pool_setipl.

most of these changes have been done with coccinelle using the spatch
below. cocci sucks at formatting code though, so i fixed that by hand.

the manpage and subr_pool.c bits i did myself.

ok tedu@ jmatthew@

@ipl@
expression pp;
expression ipl;
expression s, a, o, f, m, p;
@@
-pool_init(pp, s, a, o, f, m, p);
-pool_setipl(pp, ipl);
+pool_init(pp, s, a, ipl, f, m, p);

decouple struct uvmexp into a new file, so that uvm_extern.h and sysctl.h
don't need to be married.
ok guenther miod beck jsing kettenis

Fix a few format string bugs with -DDEBUG

Reduce uvm include madness. Use <uvm/uvm_extern.h> instead of
<uvm/uvm.h> if possible and remove double inclusions.

ok beck@, mlarkin@, deraadt@

Make mbufs and dma_alloc be contig allocations.
Requested by dlg@

ok oga@

Put back the change of pool and malloc into the new km_alloc(9) api.
The problems during the hackathon were not caused by this (most likely).

prodded by deraadt@ and beck@

Backout the uvm_km_getpage -> km_alloc conversion. Weird things are happening
and we aren't sure what's causing them.

shouted oks by many before I even built a kernel with the diff.

- Change pool constraints to use kmem_pa_mode instead of uvm_constraint_range
- Use km_alloc for all backend allocations in pools.
- Use km_alloc for the emergmency kentry allocations in uvm_mapent_alloc
- Garbage collect uvm_km_getpage, uvm_km_getpage_pla and uvm_km_putpage

ariane@ ok

The dma pools need to be IPL_VM
ok dlg

make more dma pools -- all the way up to 64K. at least the scsi
SCIOCCOMMAND wants a dma'able object that big. should we handle
this another way, by handling that data in a buf?
ok krw

limit the pools from 14 bits down. We cannot use PAGE_SIZE because it
is a variable on sparc. This should be revisited... after the arguments
for pagesize vs 4K complete :)

oops; Fred Crowson

dma_alloc() and dma_free(). This is a thin shim on top of a bag of
pools, sized by powers of 2, which are constrained to dma memory.
ok matthew tedu thib