[src/trunk]: src/sys Fix psref(9) part of PR kern/52515. It is complete to fi...

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

details:   https://anonhg.NetBSD.org/src/rev/373b3a2ed4fa
branches:  trunk
changeset: 828396:373b3a2ed4fa
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Mon Dec 11 02:33:17 2017 +0000

description:
Fix psref(9) part of PR kern/52515. It is complete to fix the PR now.

implementated by ozaki-r@n.o, reviewed by riastradh@n.o, thanks.

XXX need pullup-8

diffstat:

 sys/kern/subr_psref.c |  21 ++++++++++++---------
 sys/sys/psref.h       |   6 ++++--
 2 files changed, 16 insertions(+), 11 deletions(-)

diffs (111 lines):

diff -r 6a2470cd64b2 -r 373b3a2ed4fa sys/kern/subr_psref.c
--- a/sys/kern/subr_psref.c     Mon Dec 11 02:17:35 2017 +0000
+++ b/sys/kern/subr_psref.c     Mon Dec 11 02:33:17 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_psref.c,v 1.7 2017/06/01 02:45:13 chs Exp $       */
+/*     $NetBSD: subr_psref.c,v 1.8 2017/12/11 02:33:17 knakahara Exp $ */
 
 /*-
  * Copyright (c) 2016 The NetBSD Foundation, Inc.
@@ -64,7 +64,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_psref.c,v 1.7 2017/06/01 02:45:13 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_psref.c,v 1.8 2017/12/11 02:33:17 knakahara Exp $");
 
 #include <sys/types.h>
 #include <sys/condvar.h>
@@ -78,7 +78,7 @@
 #include <sys/queue.h>
 #include <sys/xcall.h>
 
-LIST_HEAD(psref_head, psref);
+SLIST_HEAD(psref_head, psref);
 
 static bool    _psref_held(const struct psref_target *, struct psref_class *,
                    bool);
@@ -135,7 +135,7 @@
        const struct psref_cpu *pcpu = p;
        bool *retp = cookie;
 
-       if (!LIST_EMPTY(&pcpu->pcpu_head))
+       if (!SLIST_EMPTY(&pcpu->pcpu_head))
                *retp = false;
 }
 
@@ -194,7 +194,7 @@
        bool found = false;
        struct psref *_psref;
 
-       LIST_FOREACH(_psref, &pcpu->pcpu_head, psref_entry) {
+       SLIST_FOREACH(_psref, &pcpu->pcpu_head, psref_entry) {
                if (_psref == psref &&
                    _psref->psref_target == target) {
                        found = true;
@@ -250,7 +250,7 @@
 #endif
 
        /* Record our reference.  */
-       LIST_INSERT_HEAD(&pcpu->pcpu_head, psref, psref_entry);
+       SLIST_INSERT_HEAD(&pcpu->pcpu_head, psref, psref_entry);
        psref->psref_target = target;
        psref->psref_lwp = curlwp;
        psref->psref_cpu = curcpu();
@@ -273,6 +273,7 @@
 psref_release(struct psref *psref, const struct psref_target *target,
     struct psref_class *class)
 {
+       struct psref_cpu *pcpu;
        int s;
 
        KASSERTMSG((kpreempt_disabled() || cpu_softintr_p() ||
@@ -302,7 +303,9 @@
         * (as does blocking interrupts).
         */
        s = splraiseipl(class->prc_iplcookie);
-       LIST_REMOVE(psref, psref_entry);
+       pcpu = percpu_getref(class->prc_percpu);
+       SLIST_REMOVE(&pcpu->pcpu_head, psref, psref, psref_entry);
+       percpu_putref(class->prc_percpu);
        splx(s);
 
        /* If someone is waiting for users to drain, notify 'em.  */
@@ -353,7 +356,7 @@
        pcpu = percpu_getref(class->prc_percpu);
 
        /* Record the new reference.  */
-       LIST_INSERT_HEAD(&pcpu->pcpu_head, pto, psref_entry);
+       SLIST_INSERT_HEAD(&pcpu->pcpu_head, pto, psref_entry);
        pto->psref_target = pfrom->psref_target;
        pto->psref_lwp = curlwp;
        pto->psref_cpu = curcpu();
@@ -474,7 +477,7 @@
        pcpu = percpu_getref(class->prc_percpu);
 
        /* Search through all the references on this CPU.  */
-       LIST_FOREACH(psref, &pcpu->pcpu_head, psref_entry) {
+       SLIST_FOREACH(psref, &pcpu->pcpu_head, psref_entry) {
                /* Sanity-check the reference's CPU.  */
                KASSERTMSG((psref->psref_cpu == curcpu()),
                    "passive reference transferred from CPU %u to CPU %u",
diff -r 6a2470cd64b2 -r 373b3a2ed4fa sys/sys/psref.h
--- a/sys/sys/psref.h   Mon Dec 11 02:17:35 2017 +0000
+++ b/sys/sys/psref.h   Mon Dec 11 02:33:17 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: psref.h,v 1.2 2016/12/16 20:12:11 christos Exp $       */
+/*     $NetBSD: psref.h,v 1.3 2017/12/11 02:33:17 knakahara Exp $      */
 
 /*-
  * Copyright (c) 2016 The NetBSD Foundation, Inc.
@@ -69,7 +69,9 @@
  *     written only on the local CPU.
  */
 struct psref {
-       LIST_ENTRY(psref)               psref_entry;
+       SLIST_ENTRY(psref)              psref_entry;
+       /* To keep ABI with LIST_ENTRY(psref) version. */
+       void                            *psref_unused0;
        const struct psref_target       *psref_target;
        struct lwp                      *psref_lwp;
        struct cpu_info                 *psref_cpu;