vm_unbind_root - Undoes an extant binding to the root page table of an arena

#include <charm.h>

Status vm_unbind_root( int arena_id, Cap arenacap, int pfn, Cap bindcap, bool use_hashing);

arena_id Specifies the arena from which the root page table is being removed.

arenacap The manage capability associated with the arena denoted by arena_id.

pfn Specifies the physical page frame containing the root page table.

bindcap Specifies the capability associated with pfn.

use_hashing Specifies that hashing is to be used when the page is unmapped (see below).

If use_hashing is true, the kernel will calculate a hash code for the page before it is unmapped. This hash code is stored in a kernel data structure associated with the arena. This mechanism provides an efficient means to remove and later reinstate a root page table (containing valid bindings). Without this mechanism, any extant bindings on the page would need to be recreated whenever the page was rebound. (c.f. vm_bind_root)

Upon the successful completion, the vm_unbind_root() function returns [SUCCESS].

If the vm_unbind_root() function fails, a Status is returned that corresponds to one of the following values: