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.
end of the mappable kernel virtual address space. Previously, it would
get called more often than necessary, because the caller only new what
was requested.
Also, export uvm_maxkaddr so that uvm_pageboot_alloc() can grow the
kernel pmap if necessary, as well. Note that pmap_growkernel() must
now be able to handle being called before pmap_init().
uvmspace_fork().
pmap_fork() is used to "fork a pmap", that is copy data from one pmap
to the other that is NOT related to actual mappings in the pmap, but is
otherwise logically coupled to the address space.
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.
these are the changes to the old Mach VM system to allow both to be
available in the kernel.
to vm_bootstrap_steal_memory(), since we may need to steal memory from
a direct-mapped segment at this early stage of the game (on e.g. MIPS
and Alpha).
This interface is activated by defining PMAP_STEAL_MEMORY in <machine/pmap.h>.
Otherwise, the pmap_virtual_space() prototype is in-scope for use by
vm_bootstrap_steal_memory().
called "MACHINE_NEW_NONCONGIG". this is required for UVM, the new VM
system (also written by chuck) that is coming soon. adds new functions:
vm_page_physload() -- tell the VM system about an area of memory.
vm_physseg_find() -- returns index in vm_physmem array that this
address is in.
and several new versions of old functions/macros defined in vm_page.h.
this is the MI portion. sparc, and then later i386 portions to come.
all other ports need to change to this ASAP! (alpha is already being
worked on)
This clearly needs to be fixed. I would like to declare it:
__pure u_int pmap_page_index __P((vm_offset_t));
but at least the arm port wants it signed [since it tests for -1 all over
the place]. Can we have this fixed please?
soda