svn commit: r349323 - head/sys/arm64/arm64

[Alan Cox]

Author: alc
Date: Sun Jun 23 21:06:56 2019
New Revision: 349323
URL: https://svnweb.freebsd.org/changeset/base/349323

Log:
  pmap_enter_quick_locked() never replaces a valid mapping, so it need not
  perform a TLB invalidation.  A barrier suffices.  (See r343876.)
  
  Add a comment to pmap_enter_quick_locked() in order to highlight the
  fact that it does not replace valid mappings.
  
  Correct a typo in one of pmap_enter()'s comments.
  
  MFC after:	1 week

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

Modified: head/sys/arm64/arm64/pmap.c
==============================================================================
--- head/sys/arm64/arm64/pmap.c	Sun Jun 23 19:37:12 2019	(r349322)
+++ head/sys/arm64/arm64/pmap.c	Sun Jun 23 21:06:56 2019	(r349323)
@@ -3408,7 +3408,7 @@ validate:
 			    __func__, pmap, va, new_l3);
 		}
 	} else {
-		/* New mappig */
+		/* New mapping */
 		pmap_load_store(l3, new_l3);
 		dsb(ishst);
 	}
@@ -3706,6 +3706,9 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, v
 		l3 = pmap_l2_to_l3(pde, va);
 	}
 
+	/*
+	 * Abort if a mapping already exists.
+	 */
 	if (pmap_load(l3) != 0) {
 		if (mpte != NULL) {
 			mpte->wire_count--;
@@ -3755,7 +3758,7 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, v
 		cpu_icache_sync_range(PHYS_TO_DMAP(pa), PAGE_SIZE);
 
 	pmap_load_store(l3, l3_val);
-	pmap_invalidate_page(pmap, va);
+	dsb(ishst);
 	return (mpte);
 }