[src/trunk]: src/sys/crypto/cprng_fast Move initial entropy bookkeeping out o...

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

details:   https://anonhg.NetBSD.org/src/rev/4ecf4c7d8635
branches:  trunk
changeset: 331472:4ecf4c7d8635
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 11 13:12:53 2014 +0000

description:
Move initial entropy bookkeeping out of the fast path.

diffstat:

 sys/crypto/cprng_fast/cprng_fast.c |  33 +++++++++++++++------------------
 1 files changed, 15 insertions(+), 18 deletions(-)

diffs (88 lines):

diff -r e0860adecd5b -r 4ecf4c7d8635 sys/crypto/cprng_fast/cprng_fast.c
--- a/sys/crypto/cprng_fast/cprng_fast.c        Mon Aug 11 13:06:31 2014 +0000
+++ b/sys/crypto/cprng_fast/cprng_fast.c        Mon Aug 11 13:12:53 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: cprng_fast.c,v 1.8 2014/08/11 13:06:31 riastradh Exp $ */
+/*     $NetBSD: cprng_fast.c,v 1.9 2014/08/11 13:12:53 riastradh Exp $ */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cprng_fast.c,v 1.8 2014/08/11 13:06:31 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cprng_fast.c,v 1.9 2014/08/11 13:12:53 riastradh Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -235,15 +235,23 @@
 
        cprng_strong(kern_cprng, seed, sizeof seed, FASYNC);
        cprng_fast_seed(cprng, seed);
+       cprng->have_initial = rnd_initial_entropy;
        (void)explicit_memset(seed, 0, sizeof seed);
 }
-
+
 static inline int
 cprng_fast_get(struct cprng_fast **cprngp)
 {
+       struct cprng_fast *cprng;
+       int s;
 
-       *cprngp = percpu_getref(cprng_fast_percpu);
-       return splvm();
+       *cprngp = cprng = percpu_getref(cprng_fast_percpu);
+       s = splvm();
+
+       if (__predict_false(!cprng->have_initial))
+               cprng_fast_schedule_reseed(cprng);
+
+       return s;
 }
 
 static inline void
@@ -255,7 +263,7 @@
        splx(s);
        percpu_putref(cprng_fast_percpu);
 }
-
+
 static inline void
 cprng_fast_schedule_reseed(struct cprng_fast *cprng __unused)
 {
@@ -275,6 +283,7 @@
        cprng = percpu_getref(cprng_fast_percpu);
        s = splvm();
        cprng_fast_seed(cprng, seed);
+       cprng->have_initial = rnd_initial_entropy;
        splx(s);
        percpu_putref(cprng_fast_percpu);
 
@@ -300,12 +309,6 @@
        (void)memset(cprng->buffer, 0, sizeof cprng->buffer);
        (void)memcpy(cprng->key, seed, sizeof cprng->key);
        (void)memset(cprng->nonce, 0, sizeof cprng->nonce);
-
-       if (__predict_true(rnd_initial_entropy)) {
-               cprng->have_initial = true;
-       } else {
-               cprng->have_initial = false;
-       }
 }
 
 static inline uint32_t
@@ -322,12 +325,6 @@
                if (__predict_false(++cprng->nonce[0] == 0)) {
                        cprng->nonce[1]++;
                        cprng_fast_schedule_reseed(cprng);
-               } else {
-                       if (__predict_false(false == cprng->have_initial)) {
-                               if (rnd_initial_entropy) {
-                                       cprng_fast_schedule_reseed(cprng);
-                               }
-                       }
                }
                v = cprng->buffer[CPRNG_FAST_BUFIDX];
                cprng->buffer[CPRNG_FAST_BUFIDX] = CPRNG_FAST_BUFIDX;