Migrate pmap_prefault() into the machine-independent virtual memory layer.

A small helper function pmap_is_prefaultable() is added.  This function
encapsulate the few lines of pmap_prefault() that actually vary from
machine to machine.  Note: pmap_is_prefaultable() and pmap_mincore() have
much in common.  Going forward, it's worth considering their merger.

1 files changed, 17 insertions, 95 deletions

diff --git a/sys/ia64/ia64/pmap.c b/sys/ia64/ia64/pmap.c
index a404707..40400cf 100644
--- a/sys/ia64/ia64/pmap.c
+++ b/sys/ia64/ia64/pmap.c
@@ -1736,101 +1736,6 @@ pmap_object_init_pt(pmap_t pmap, vm_offset_t addr,
 }
 
 /*
- * pmap_prefault provides a quick way of clustering
- * pagefaults into a processes address space.  It is a "cousin"
- * of pmap_object_init_pt, except it runs at page fault time instead
- * of mmap time.
- */
-#define PFBAK 4
-#define PFFOR 4
-#define PAGEORDER_SIZE (PFBAK+PFFOR)
-
-static int pmap_prefault_pageorder[] = {
-	-1 * PAGE_SIZE, 1 * PAGE_SIZE,
-	-2 * PAGE_SIZE, 2 * PAGE_SIZE,
-	-3 * PAGE_SIZE, 3 * PAGE_SIZE,
-	-4 * PAGE_SIZE, 4 * PAGE_SIZE
-};
-
-void
-pmap_prefault(pmap, addra, entry)
-	pmap_t pmap;
-	vm_offset_t addra;
-	vm_map_entry_t entry;
-{
-	int i;
-	vm_offset_t starta;
-	vm_offset_t addr;
-	vm_pindex_t pindex;
-	vm_page_t m, mpte;
-	vm_object_t object;
-
-	if (!curthread || (pmap != vmspace_pmap(curthread->td_proc->p_vmspace)))
-		return;
-
-	object = entry->object.vm_object;
-
-	starta = addra - PFBAK * PAGE_SIZE;
-	if (starta < entry->start) {
-		starta = entry->start;
-	} else if (starta > addra) {
-		starta = 0;
-	}
-
-	mpte = NULL;
-	for (i = 0; i < PAGEORDER_SIZE; i++) {
-		vm_object_t backing_object, lobject;
-		struct ia64_lpte *pte;
-
-		addr = addra + pmap_prefault_pageorder[i];
-		if (addr > addra + (PFFOR * PAGE_SIZE))
-			addr = 0;
-
-		if (addr < starta || addr >= entry->end)
-			continue;
-
-		pte = pmap_find_vhpt(addr);
-		if (pte && pte->pte_p)
-			continue;
-
-		pindex = ((addr - entry->start) + entry->offset) >> PAGE_SHIFT;
-		lobject = object;
-		VM_OBJECT_LOCK(lobject);
-		while ((m = vm_page_lookup(lobject, pindex)) == NULL &&
-		    lobject->type == OBJT_DEFAULT &&
-		    (backing_object = lobject->backing_object) != NULL) {
-			if (lobject->backing_object_offset & PAGE_MASK)
-				break;
-			pindex += lobject->backing_object_offset >> PAGE_SHIFT;
-			VM_OBJECT_LOCK(backing_object);
-			VM_OBJECT_UNLOCK(lobject);
-			lobject = backing_object;
-		}
-		VM_OBJECT_UNLOCK(lobject);
-		/*
-		 * give-up when a page is not in memory
-		 */
-		if (m == NULL)
-			break;
-		vm_page_lock_queues();
-		if (((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
-			(m->busy == 0) &&
-		    (m->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) {
-
-			if ((m->queue - m->pc) == PQ_CACHE) {
-				vm_page_deactivate(m);
-			}
-			vm_page_busy(m);
-			vm_page_unlock_queues();
-			pmap_enter_quick(pmap, addr, m, NULL);
-			vm_page_lock_queues();
-			vm_page_wakeup(m);
-		}
-		vm_page_unlock_queues();
-	}
-}
-
-/*
  *	Routine:	pmap_change_wiring
  *	Function:	Change the wiring attribute for a map/virtual-address
  *			pair.
@@ -2148,6 +2053,23 @@ pmap_is_modified(vm_page_t m)
 }
 
 /*
+ *	pmap_is_prefaultable:
+ *
+ *	Return whether or not the specified virtual address is elgible
+ *	for prefault.
+ */
+boolean_t
+pmap_is_prefaultable(pmap_t pmap, vm_offset_t addr)
+{
+	struct ia64_lpte *pte;
+
+	pte = pmap_find_vhpt(addr);
+	if (pte && pte->pte_p)
+		return (FALSE);
+	return (TRUE);
+}
+
+/*
  *	Clear the modify bits on the specified physical page.
  */
 void