[src/trunk]: src/sys/rump/librump/rumpkern Call rnd_add_data asynchronously f...

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

details:   https://anonhg.NetBSD.org/src/rev/e420625b379d
branches:  trunk
changeset: 331594:e420625b379d
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Fri Aug 15 15:04:33 2014 +0000

description:
Call rnd_add_data asynchronously for the rump hyperentropy callback.

Avoids recursion rnd_getmore -> rnd_add_data -> rnd_getmore, which is
silly but I don't have time to fix it properly right now.

diffstat:

 sys/rump/librump/rumpkern/hyperentropy.c |  36 +++++++++++++++++++++++++++----
 1 files changed, 31 insertions(+), 5 deletions(-)

diffs (77 lines):

diff -r 4534ec866cb4 -r e420625b379d sys/rump/librump/rumpkern/hyperentropy.c
--- a/sys/rump/librump/rumpkern/hyperentropy.c  Fri Aug 15 15:03:03 2014 +0000
+++ b/sys/rump/librump/rumpkern/hyperentropy.c  Fri Aug 15 15:04:33 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: hyperentropy.c,v 1.3 2014/08/10 16:44:36 tls Exp $     */
+/*     $NetBSD: hyperentropy.c,v 1.4 2014/08/15 15:04:33 riastradh Exp $       */
 
 /*
  * Copyright (c) 2014 Antti Kantee.  All Rights Reserved.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: hyperentropy.c,v 1.3 2014/08/10 16:44:36 tls Exp $");
+__KERNEL_RCSID(0, "$NetBSD: hyperentropy.c,v 1.4 2014/08/15 15:04:33 riastradh Exp $");
 
 #include <sys/param.h>
 #include <sys/kmem.h>
@@ -37,10 +37,12 @@
 #include "rump_private.h"
 
 static krndsource_t rndsrc;
+static volatile unsigned hyperentropy_wanted;
+static void *feedrandom_softint;
 
 #define MAXGET (RND_POOLBITS/NBBY)
 static void
-feedrandom(size_t bytes, void *arg)
+feedrandom(size_t bytes)
 {
        uint8_t *rnddata;
        size_t dsize;
@@ -52,18 +54,42 @@
        kmem_intr_free(rnddata, MAXGET);
 }
 
+static void
+feedrandom_intr(void *cookie __unused)
+{
+
+       feedrandom(atomic_swap_uint(&hyperentropy_wanted, 0));
+}
+
+static void
+feedrandom_cb(size_t bytes, void *cookie __unused)
+{
+       unsigned old, new;
+
+       do {
+               old = hyperentropy_wanted;
+               new = ((MAXGET - old) < bytes? MAXGET : (old + bytes));
+       } while (atomic_cas_uint(&hyperentropy_wanted, old, new) != old);
+
+       softint_schedule(feedrandom_softint);
+}
+
 void
 rump_hyperentropy_init(void)
 {
 
        if (rump_threads) {
-               rndsource_setcb(&rndsrc, feedrandom, &rndsrc);
+               feedrandom_softint =
+                   softint_establish(SOFTINT_CLOCK|SOFTINT_MPSAFE,
+                       feedrandom_intr, NULL);
+               KASSERT(feedrandom_softint != NULL);
+               rndsource_setcb(&rndsrc, feedrandom_cb, &rndsrc);
                rnd_attach_source(&rndsrc, "rump_hyperent", RND_TYPE_VM,
                    RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
        } else {
                /* without threads, just fill the pool */
                rnd_attach_source(&rndsrc, "rump_hyperent", RND_TYPE_VM,
                    RND_FLAG_COLLECT_VALUE);
-               feedrandom(RND_POOLBITS/NBBY, NULL);
+               feedrandom(MAXGET);
        }
 }