svn commit: r321003 - head/sys/amd64/amd64

[Alan Cox]

Author: alc
Date: Sat Jul 15 01:49:54 2017
New Revision: 321003
URL: https://svnweb.freebsd.org/changeset/base/321003

Log:
  Extract the innermost loop of pmap_remove() out into its own function,
  pmap_remove_ptes().  (This new function will also be used by an upcoming
  change to pmap_enter() that adds support for psind == 1 mappings.)
  
  Submitted by:	Yufeng Zhou <yz70 at rice.edu> (an earlier version)
  Reviewed by:	kib, markj
  MFC after:	1 week

Modified:
  head/sys/amd64/amd64/pmap.c

Modified: head/sys/amd64/amd64/pmap.c
==============================================================================
--- head/sys/amd64/amd64/pmap.c	Sat Jul 15 00:45:22 2017	(r321002)
+++ head/sys/amd64/amd64/pmap.c	Sat Jul 15 01:49:54 2017	(r321003)
@@ -629,6 +629,9 @@ static int pmap_remove_pte(pmap_t pmap, pt_entry_t *pt
 static vm_page_t pmap_remove_pt_page(pmap_t pmap, vm_offset_t va);
 static void pmap_remove_page(pmap_t pmap, vm_offset_t va, pd_entry_t *pde,
     struct spglist *free);
+static bool	pmap_remove_ptes(pmap_t pmap, vm_offset_t sva, vm_offset_t eva,
+		    pd_entry_t *pde, struct spglist *free,
+		    struct rwlock **lockp);
 static boolean_t pmap_try_insert_pv_entry(pmap_t pmap, vm_offset_t va,
     vm_page_t m, struct rwlock **lockp);
 static void pmap_update_pde(pmap_t pmap, vm_offset_t va, pd_entry_t *pde,
@@ -3736,6 +3739,44 @@ pmap_remove_page(pmap_t pmap, vm_offset_t va, pd_entry
 }
 
 /*
+ * Removes the specified range of addresses from the page table page.
+ */
+static bool
+pmap_remove_ptes(pmap_t pmap, vm_offset_t sva, vm_offset_t eva,
+    pd_entry_t *pde, struct spglist *free, struct rwlock **lockp)
+{
+	pt_entry_t PG_G, *pte;
+	vm_offset_t va;
+	bool anyvalid;
+
+	PMAP_LOCK_ASSERT(pmap, MA_OWNED);
+	PG_G = pmap_global_bit(pmap);
+	anyvalid = false;
+	va = eva;
+	for (pte = pmap_pde_to_pte(pde, sva); sva != eva; pte++,
+	    sva += PAGE_SIZE) {
+		if (*pte == 0) {
+			if (va != eva) {
+				pmap_invalidate_range(pmap, va, sva);
+				va = eva;
+			}
+			continue;
+		}
+		if ((*pte & PG_G) == 0)
+			anyvalid = true;
+		else if (va == eva)
+			va = sva;
+		if (pmap_remove_pte(pmap, pte, sva, *pde, free, lockp)) {
+			sva += PAGE_SIZE;
+			break;
+		}
+	}
+	if (va != eva)
+		pmap_invalidate_range(pmap, va, sva);
+	return (anyvalid);
+}
+
+/*
  *	Remove the given range of addresses from the specified map.
  *
  *	It is assumed that the start and end are properly
@@ -3745,11 +3786,11 @@ void
 pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
 {
 	struct rwlock *lock;
-	vm_offset_t va, va_next;
+	vm_offset_t va_next;
 	pml4_entry_t *pml4e;
 	pdp_entry_t *pdpe;
 	pd_entry_t ptpaddr, *pde;
-	pt_entry_t *pte, PG_G, PG_V;
+	pt_entry_t PG_G, PG_V;
 	struct spglist free;
 	int anyvalid;
 
@@ -3852,28 +3893,8 @@ pmap_remove(pmap_t pmap, vm_offset_t sva, vm_offset_t 
 		if (va_next > eva)
 			va_next = eva;
 
-		va = va_next;
-		for (pte = pmap_pde_to_pte(pde, sva); sva != va_next; pte++,
-		    sva += PAGE_SIZE) {
-			if (*pte == 0) {
-				if (va != va_next) {
-					pmap_invalidate_range(pmap, va, sva);
-					va = va_next;
-				}
-				continue;
-			}
-			if ((*pte & PG_G) == 0)
-				anyvalid = 1;
-			else if (va == va_next)
-				va = sva;
-			if (pmap_remove_pte(pmap, pte, sva, ptpaddr, &free,
-			    &lock)) {
-				sva += PAGE_SIZE;
-				break;
-			}
-		}
-		if (va != va_next)
-			pmap_invalidate_range(pmap, va, sva);
+		if (pmap_remove_ptes(pmap, sva, va_next, pde, &free, &lock))
+			anyvalid = 1;
 	}
 	if (lock != NULL)
 		rw_wunlock(lock);