the lower bits; UVM provides us page-aligned addresses for
everything. For the paranoid, we'll leave KDASSERT()'s in
that check for this if the kernel is built with DEBUG.
Low-hanging fruit that shaves some cycles.
pmap.h and give them more descriptive names and better comments:
* PT_M -> PVF_MOD (page is modified)
* PT_H -> PVF_REF (page is referenced)
* PT_W -> PVF_WIRED (mapping is wired)
* PT_Wr -> PVF_WRITE (mapping is writable)
* PT_NC -> PVF_NC (mapping is non-cacheable; multiple mappings)
* Don't refer to VA 0, instead refer to a new variable: vector_page
* Delete the old zero_page_*() functions, replacing them with a new
one: vector_page_setprot().
* When manipulating vector page mappings in user pmaps, only do so if
the vector page is below KERNEL_BASE (if it's above KERNEL_BASE, the
vector page is mapped by the kernel pmap).
* Add a new function, arm32_vector_init(), which takes the virtual
address of the vector page (which MUST be valid when the function
is called) and a bitmask of vectors the kernel is going to take
over, and performs all vector page initialization, including setting
the V bit in the CPU Control register ("relocate vectors to high
address"), if necessary.
when the part being quiried was mapped with a section (!) giving weird
results and had become a mess of goto's.
Complete rewrite and cleaned up the `goto'-jungle entirely ... ripped all
goto's. The resulting code is much better to read and might even have a
small performance gain.
I/O processors:
* The i80200 and the i80321 have the same CPU ID, so split the
CPU_XSCALE option into CPU_XSCALE_80200 and CPU_XSCALE_80321
options, and don't let them both be defined at the same time.
XXX May want to revisit this in the future.
* Split some registers common between the i80200 and i80321 into
<arm/xscale/xscalereg.h>.
* Rename a few existing functions.
pmap_copy_page() will never have any mappings. Therefore, it
is unnecessary to do a cache clean for that page.
Add assertions in #ifdef DEBUG that assert this invariant.
This shaves some cycles off the frequently-called pmap_zero_page()
and pmap_copy_page() (no need to look up the dst page's vm_page
structure, and one less function call to clean the page).
