[src/trunk]: src/sys/arch/hp700/dev Add a comment and check off in mmmmap.

[skrll <skrll%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/eff50bbe4d94
branches:  trunk
changeset: 755384:eff50bbe4d94
user:      skrll <skrll%NetBSD.org@localhost>
date:      Thu Jun 03 22:34:26 2010 +0000

description:
Add a comment and check off in mmmmap.

diffstat:

 sys/arch/hp700/dev/mem.c |  19 +++++++++++++------
 1 files changed, 13 insertions(+), 6 deletions(-)

diffs (46 lines):

diff -r a8f101ca90bb -r eff50bbe4d94 sys/arch/hp700/dev/mem.c
--- a/sys/arch/hp700/dev/mem.c  Thu Jun 03 20:48:48 2010 +0000
+++ b/sys/arch/hp700/dev/mem.c  Thu Jun 03 22:34:26 2010 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mem.c,v 1.24 2010/04/28 06:06:11 skrll Exp $   */
+/*     $NetBSD: mem.c,v 1.25 2010/06/03 22:34:26 skrll Exp $   */
 
 /*     $OpenBSD: mem.c,v 1.30 2007/09/22 16:21:32 krw Exp $    */
 /*
@@ -73,7 +73,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: mem.c,v 1.24 2010/04/28 06:06:11 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: mem.c,v 1.25 2010/06/03 22:34:26 skrll Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -400,16 +400,23 @@
 mmmmap(dev_t dev, off_t off, int prot)
 {
 
+        /*
+         * /dev/mem is the only one that makes sense through this
+         * interface.  For /dev/kmem any physaddr we return here
+         * could be transient and hence incorrect or invalid at
+         * a later time.  /dev/null just doesn't make any sense
+         * and /dev/zero is a hack that is handled via the default
+         * pager in mmap().
+         */
+
        if (minor(dev) != DEV_MEM)
                return -1;
 
        /*
         * Allow access only in RAM.
         */
-#if 0
-       if (off < ptoa(firstusablepage) ||
-           off >= ptoa(lastusablepage + 1))
+       if (off > ptoa(physmem))
                return -1;
-#endif
+
        return btop(off);
 }