[src/trunk]: src/sys/sys autoconf: Blame devices holding up boot with config_...

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

details:   https://anonhg.NetBSD.org/src/rev/74e5eb59a7bd
branches:  trunk
changeset: 944575:74e5eb59a7bd
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Sat Oct 03 22:32:50 2020 +0000

description:
autoconf: Blame devices holding up boot with config_pending.

Blame message requires `boot -x' (AB_DEBUG).

Fix ata so it doesn't mismatch config_pending_incr/decr devices.

diffstat:

 sys/dev/ata/ata.c        |   8 ++++----
 sys/kern/subr_autoconf.c |  30 ++++++++++++++++++++----------
 sys/sys/device.h         |   5 ++++-
 3 files changed, 28 insertions(+), 15 deletions(-)

diffs (132 lines):

diff -r fca6d05d8f34 -r 74e5eb59a7bd sys/dev/ata/ata.c
--- a/sys/dev/ata/ata.c Sat Oct 03 22:27:00 2020 +0000
+++ b/sys/dev/ata/ata.c Sat Oct 03 22:32:50 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ata.c,v 1.159 2020/05/25 19:05:30 jdolecek Exp $       */
+/*     $NetBSD: ata.c,v 1.160 2020/10/03 22:32:50 riastradh Exp $      */
 
 /*
  * Copyright (c) 1998, 2001 Manuel Bouyer.  All rights reserved.
@@ -25,7 +25,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ata.c,v 1.159 2020/05/25 19:05:30 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ata.c,v 1.160 2020/10/03 22:32:50 riastradh Exp $");
 
 #include "opt_ata.h"
 
@@ -298,7 +298,7 @@
 
        ata_delref(chp);
 
-       config_pending_decr(atac->atac_dev);
+       config_pending_decr(atabus_sc->sc_dev);
 }
 
 /*
@@ -424,7 +424,7 @@
 
        ata_delref(chp);
 
-       config_pending_decr(atac->atac_dev);
+       config_pending_decr(atabus_sc->sc_dev);
        kthread_exit(0);
 }
 
diff -r fca6d05d8f34 -r 74e5eb59a7bd sys/kern/subr_autoconf.c
--- a/sys/kern/subr_autoconf.c  Sat Oct 03 22:27:00 2020 +0000
+++ b/sys/kern/subr_autoconf.c  Sat Oct 03 22:32:50 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_autoconf.c,v 1.273 2020/08/01 11:18:26 jdolecek Exp $ */
+/* $NetBSD: subr_autoconf.c,v 1.274 2020/10/03 22:32:50 riastradh Exp $ */
 
 /*
  * Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -77,7 +77,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.273 2020/08/01 11:18:26 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.274 2020/10/03 22:32:50 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -224,7 +224,8 @@
 static int alldevs_nwrite = 0;
 static bool alldevs_garbage = false;
 
-static int config_pending;             /* semaphore for mountroot */
+static struct devicelist config_pending =
+    TAILQ_HEAD_INITIALIZER(config_pending);
 static kmutex_t config_misc_lock;
 static kcondvar_t config_misc_cv;
 
@@ -2095,9 +2096,12 @@
 {
 
        mutex_enter(&config_misc_lock);
-       config_pending++;
+       KASSERTMSG(dev->dv_pending < INT_MAX,
+           "%s: excess config_pending_incr", device_xname(dev));
+       if (dev->dv_pending++ == 0)
+               TAILQ_INSERT_TAIL(&config_pending, dev, dv_pending_list);
 #ifdef DEBUG_AUTOCONF
-       printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
+       printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
 #endif
        mutex_exit(&config_misc_lock);
 }
@@ -2106,13 +2110,15 @@
 config_pending_decr(device_t dev)
 {
 
-       KASSERT(0 < config_pending);
        mutex_enter(&config_misc_lock);
-       config_pending--;
+       KASSERTMSG(dev->dv_pending > 0,
+           "%s: excess config_pending_decr", device_xname(dev));
+       if (--dev->dv_pending == 0)
+               TAILQ_REMOVE(&config_pending, dev, dv_pending_list);
 #ifdef DEBUG_AUTOCONF
-       printf("%s: %s %d\n", __func__, device_xname(dev), config_pending);
+       printf("%s: %s %d\n", __func__, device_xname(dev), dev->dv_pending);
 #endif
-       if (config_pending == 0)
+       if (TAILQ_EMPTY(&config_pending))
                cv_broadcast(&config_misc_cv);
        mutex_exit(&config_misc_lock);
 }
@@ -2165,8 +2171,12 @@
         * them to finish any deferred autoconfiguration.
         */
        mutex_enter(&config_misc_lock);
-       while (config_pending != 0)
+       while (!TAILQ_EMPTY(&config_pending)) {
+               device_t dev;
+               TAILQ_FOREACH(dev, &config_pending, dv_pending_list)
+                       aprint_debug_dev(dev, "holding up boot\n");
                cv_wait(&config_misc_cv, &config_misc_lock);
+       }
        mutex_exit(&config_misc_lock);
 
        KERNEL_LOCK(1, NULL);
diff -r fca6d05d8f34 -r 74e5eb59a7bd sys/sys/device.h
--- a/sys/sys/device.h  Sat Oct 03 22:27:00 2020 +0000
+++ b/sys/sys/device.h  Sat Oct 03 22:32:50 2020 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: device.h,v 1.157 2018/12/01 01:51:38 msaitoh Exp $ */
+/* $NetBSD: device.h,v 1.158 2020/10/03 22:32:50 riastradh Exp $ */
 
 /*
  * Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -165,6 +165,9 @@
        int             *dv_locators;   /* our actual locators (optional) */
        prop_dictionary_t dv_properties;/* properties dictionary */
 
+       int             dv_pending;     /* config_pending count */
+       TAILQ_ENTRY(device) dv_pending_list;
+
        size_t          dv_activity_count;
        void            (**dv_activity_handlers)(device_t, devactive_t);