value (KERN_SUCCESS or KERN_RESOURCE_SHORTAGE) indicating if it succeeded
or failed. Change the `wired' and `access_type' arguments to a single
`flags' argument, which includes the access type, and flags:
PMAP_WIRED the old `wired' boolean
PMAP_CANFAIL pmap_enter() is allowed to fail
If PMAP_CANFAIL is not specified, the pmap should behave as it always
has in the face of a drastic resource shortage: fall over dead.
Change the fault handler to deal with failure (which indicates resource
shortage) by unlocking everything, waiting for the pagedaemon to free
more memory, then retrying the fault.
looking up a kernel address, check to see if the address is on this
"interrupt-safe" list. If so, return failure immediately. This prevents
a locking screw if a page fault is taken on an interrupt-safe map in or
out of interrupt context.
access_type to pmap_enter() to ensure that when these mappings are accessed,
possibly in interrupt context, that they won't cause mod/ref emulation
page faults.
has PAGEABLE and INTRSAFE flags. PAGEABLE now really means "pageable",
not "allocate vm_map_entry's from non-static pool", so update all map
creations to reflect that. INTRSAFE maps are maps that are used in
interrupt context (e.g. kmem_map, mb_map), and thus use the static
map entry pool (XXX as does kernel_map, for now). This will eventually
change now these maps are locked, as well.
which can be used in an interrupt context. Use pmap_kenter*() and
pmap_kremove() only for mappings owned by these objects.
Fixes some locking protocol issues related to MP support, and eliminates
all of the pmap_enter vs. pmap_kremove inconsistencies.
define a flag UVM_PGA_USERESERVE to allow non-kernel object
allocations to use pages from the reserve.
use the new flag for allocations in pmap modules.
memory access a mapping was caused by. This is passed through from uvm_fault()
and udv_fault(), and in most other cases is 0.
The pmap module may use this to preset R/M information. On MMUs which require
R/M emulation, the implementation may preset the bits and avoid taking another
fault. On MMUs which keep R/M information in hardware, the implementation may
preset its cached bits to speed up the next call to pmap_is_modified() or
pmap_is_referenced().
UVM was written by chuck cranor <chuck@maria.wustl.edu>, with some
minor portions derived from the old Mach code. i provided some help
getting swap and paging working, and other bug fixes/ideas. chuck
silvers <chuq@chuq.com> also provided some other fixes.
this is the UVM kernel code portion.
this will be KNF'd shortly. :-)
chs