svn commit: r328658 - head/sys/arm64/arm64

[Andrew Turner]

Author: andrew
Date: Thu Feb  1 14:26:26 2018
New Revision: 328658
URL: https://svnweb.freebsd.org/changeset/base/328658

Log:
  Only promote userspace mappings to superpages. This was dropped in r328510,
  however due to the break-before-make requirement on arm64 is is currently
  unsafe to promote kernel pages.
  
  Sponsored by:	DARPA, AFRL

Modified:
  head/sys/arm64/arm64/pmap.c

Modified: head/sys/arm64/arm64/pmap.c
==============================================================================
--- head/sys/arm64/arm64/pmap.c	Thu Feb  1 13:17:42 2018	(r328657)
+++ head/sys/arm64/arm64/pmap.c	Thu Feb  1 14:26:26 2018	(r328658)
@@ -3076,12 +3076,13 @@ validate:
 	}
 
 #if VM_NRESERVLEVEL > 0
-		if ((mpte == NULL || mpte->wire_count == NL3PG) &&
-		    pmap_superpages_enabled() &&
-		    (m->flags & PG_FICTITIOUS) == 0 &&
-		    vm_reserv_level_iffullpop(m) == 0) {
-			pmap_promote_l2(pmap, pde, va, &lock);
-		}
+	if (pmap != pmap_kernel() &&
+	    (mpte == NULL || mpte->wire_count == NL3PG) &&
+	    pmap_superpages_enabled() &&
+	    (m->flags & PG_FICTITIOUS) == 0 &&
+	    vm_reserv_level_iffullpop(m) == 0) {
+		pmap_promote_l2(pmap, pde, va, &lock);
+	}
 #endif
 
 	if (lock != NULL)