[src/trunk]: src/sys/dev cleaner and safer version of the previous, for arch'...

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

details:   https://anonhg.NetBSD.org/src/rev/8d8dfc516b69
branches:  trunk
changeset: 537875:8d8dfc516b69
user:      dan <dan%NetBSD.org@localhost>
date:      Mon Oct 07 04:51:00 2002 +0000

description:
cleaner and safer version of the previous, for arch's that may define
__HAVE_CPU_COUNTER but where not all machines actually have one.

diffstat:

 sys/dev/rnd.c |  32 ++++++++++++++++----------------
 1 files changed, 16 insertions(+), 16 deletions(-)

diffs (76 lines):

diff -r 1ccb907f0be9 -r 8d8dfc516b69 sys/dev/rnd.c
--- a/sys/dev/rnd.c     Mon Oct 07 04:05:55 2002 +0000
+++ b/sys/dev/rnd.c     Mon Oct 07 04:51:00 2002 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: rnd.c,v 1.29 2002/10/07 02:38:41 dan Exp $     */
+/*     $NetBSD: rnd.c,v 1.30 2002/10/07 04:51:00 dan Exp $     */
 
 /*-
  * Copyright (c) 1997 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rnd.c,v 1.29 2002/10/07 02:38:41 dan Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rnd.c,v 1.30 2002/10/07 04:51:00 dan Exp $");
 
 #include <sys/param.h>
 #include <sys/ioctl.h>
@@ -190,9 +190,12 @@
        if (cpu_hascounter())
                return (cpu_counter() & 0xffffffff);
 #endif
-       microtime(&tv);
-
-       return (tv.tv_sec * 1000000 + tv.tv_usec);
+       if (rnd_ready) {
+               microtime(&tv);
+               return (tv.tv_sec * 1000000 + tv.tv_usec);
+       } 
+       /* when called from rnd_init, its too early to call microtime safely */
+       return 0;  
 }
 
 /*
@@ -285,16 +288,12 @@
 void
 rnd_init(void)
 {
-#ifdef __HAVE_CPU_COUNTER
        u_int32_t c;
-#endif
 
        if (rnd_ready)
                return;
 
-#ifdef __HAVE_CPU_COUNTER
        c = rnd_counter();
-#endif
 
        LIST_INIT(&rnd_sources);
        SIMPLEQ_INIT(&rnd_samples);
@@ -304,16 +303,17 @@
 
        rndpool_init(&rnd_pool);
 
-#ifdef __HAVE_CPU_COUNTER
        /* Mix *something*, *anything* into the pool to help it get started. 
-        * However, it's not safe for rnd_counter to call microtime() yet, so 
-        * we can only do this on platforms with a cpu counter.
+        * However, it's not safe for rnd_counter() to call microtime() yet,
+        * so on some platforms we might just end up with zeros anyway.
         * XXX more things to add would be nice.
         */ 
-       rndpool_add_data(&rnd_pool, &c, sizeof(u_int32_t), 0);
-       c = rnd_counter();
-       rndpool_add_data(&rnd_pool, &c, sizeof(u_int32_t), 0);
-#endif
+       if (c) {
+               rndpool_add_data(&rnd_pool, &c, sizeof(u_int32_t), 0);
+               c = rnd_counter();
+               rndpool_add_data(&rnd_pool, &c, sizeof(u_int32_t), 0);
+       }
+
        rnd_ready = 1;
 
 #ifdef RND_VERBOSE