[src/trunk]: src/sys/arch/mips/ingenic Adapt CI20 HWRNG to synchronous on-dem...

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

details:   https://anonhg.NetBSD.org/src/rev/9f26d348ef3e
branches:  trunk
changeset: 813780:9f26d348ef3e
user:      macallan <macallan%NetBSD.org@localhost>
date:      Wed Feb 17 20:12:42 2016 +0000

description:
Adapt CI20 HWRNG to synchronous on-demand callback.
Omit needless softint/locking dance.
from riastradh@

diffstat:

 sys/arch/mips/ingenic/ingenic_rng.c |  76 +++++++-----------------------------
 1 files changed, 16 insertions(+), 60 deletions(-)

diffs (133 lines):

diff -r 6a48b2de7f05 -r 9f26d348ef3e sys/arch/mips/ingenic/ingenic_rng.c
--- a/sys/arch/mips/ingenic/ingenic_rng.c       Wed Feb 17 20:11:17 2016 +0000
+++ b/sys/arch/mips/ingenic/ingenic_rng.c       Wed Feb 17 20:12:42 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ingenic_rng.c,v 1.3 2015/11/17 16:53:21 macallan Exp $ */
+/*     $NetBSD: ingenic_rng.c,v 1.4 2016/02/17 20:12:42 macallan Exp $ */
 
 /*-
  * Copyright (c) 2015 Michael McConville
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ingenic_rng.c,v 1.3 2015/11/17 16:53:21 macallan Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ingenic_rng.c,v 1.4 2016/02/17 20:12:42 macallan Exp $");
 
 /*
  * adapted from Jared McNeill's amlogic_rng.c
@@ -39,9 +39,7 @@
 #include <sys/mutex.h>
 #include <sys/kernel.h>
 #include <sys/mutex.h>
-#include <sys/callout.h>
 #include <sys/bus.h>
-#include <sys/workqueue.h>
 #include <sys/rndpool.h>
 #include <sys/rndsource.h>
 
@@ -55,22 +53,15 @@
 static int     ingenic_rng_match(device_t, cfdata_t, void *);
 static void    ingenic_rng_attach(device_t, device_t, void *);
 
-static void    ingenic_rng_get(struct ingenic_rng_softc *);
-static void    ingenic_rng_get_intr(void *);
-static void    ingenic_rng_get_cb(size_t, void *);
+static void    ingenic_rng_get(size_t, void *);
 
 struct ingenic_rng_softc {
        device_t                sc_dev;
        bus_space_tag_t         sc_bst;
        bus_space_handle_t      sc_bsh;
 
-       void *                  sc_sih;
-
+       kmutex_t                sc_lock;
        krndsource_t            sc_rndsource;
-       size_t                  sc_bytes_wanted;
-
-       kmutex_t                sc_intr_lock;
-       kmutex_t                sc_rnd_lock;
 };
 
 CFATTACH_DECL_NEW(ingenic_rng, sizeof(struct ingenic_rng_softc),
@@ -104,67 +95,32 @@
                return;
        }
 
-       mutex_init(&sc->sc_intr_lock, MUTEX_DEFAULT, IPL_SERIAL);
-       mutex_init(&sc->sc_rnd_lock, MUTEX_DEFAULT, IPL_SERIAL);
-       
+       mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
+
        aprint_naive(": Ingenic random number generator\n");
        aprint_normal(": Ingenic random number generator\n");
 
-       sc->sc_sih = softint_establish(SOFTINT_SERIAL|SOFTINT_MPSAFE,
-           ingenic_rng_get_intr, sc);
-       if (sc->sc_sih == NULL) {
-               aprint_error_dev(self, "couldn't establish softint\n");
-               return;
-       }
-
-       rndsource_setcb(&sc->sc_rndsource, ingenic_rng_get_cb, sc);
+       rndsource_setcb(&sc->sc_rndsource, ingenic_rng_get, sc);
        rnd_attach_source(&sc->sc_rndsource, device_xname(self), RND_TYPE_RNG,
            RND_FLAG_COLLECT_VALUE|RND_FLAG_HASCB);
 
-       ingenic_rng_get_cb(RND_POOLBITS / NBBY, sc);
+       ingenic_rng_get(RND_POOLBITS / NBBY, sc);
 }
 
 static void
-ingenic_rng_get(struct ingenic_rng_softc *sc)
+ingenic_rng_get(size_t bytes_wanted, void *priv)
 {
+       struct ingenic_rng_softc * const sc = priv;
        uint32_t data;
 
-       mutex_spin_enter(&sc->sc_intr_lock);
-       while (sc->sc_bytes_wanted) {
+       mutex_spin_enter(&sc->sc_lock);
+       while (bytes_wanted) {
                data = bus_space_read_4(sc->sc_bst, sc->sc_bsh, 0);
-               mutex_spin_exit(&sc->sc_intr_lock);
-               mutex_spin_enter(&sc->sc_rnd_lock);
-               rnd_add_data(&sc->sc_rndsource, &data, sizeof(data),
+               delay(1);
+               rnd_add_data_sync(&sc->sc_rndsource, &data, sizeof(data),
                    sizeof(data) * NBBY);
-               mutex_spin_exit(&sc->sc_rnd_lock);
-               mutex_spin_enter(&sc->sc_intr_lock);
-               sc->sc_bytes_wanted -= MIN(sc->sc_bytes_wanted, sizeof(data));
+               bytes_wanted -= MIN(bytes_wanted, sizeof(data));
        }
        explicit_memset(&data, 0, sizeof(data));
-       mutex_spin_exit(&sc->sc_intr_lock);
+       mutex_spin_exit(&sc->sc_lock);
 }
-
-static void
-ingenic_rng_get_cb(size_t bytes_wanted, void *priv)
-{
-       struct ingenic_rng_softc * const sc = priv;
-
-       mutex_spin_enter(&sc->sc_intr_lock);
-       if (sc->sc_bytes_wanted == 0)
-               softint_schedule(sc->sc_sih);
-
-       if (bytes_wanted > (UINT_MAX - sc->sc_bytes_wanted))
-               sc->sc_bytes_wanted = UINT_MAX;
-       else
-               sc->sc_bytes_wanted += bytes_wanted;
-
-       mutex_spin_exit(&sc->sc_intr_lock);
-}
-
-static void
-ingenic_rng_get_intr(void *priv)
-{
-       struct ingenic_rng_softc * const sc = priv;
-
-       ingenic_rng_get(sc);
-}