[src/trunk]: src/sys/external/bsd/drm2/linux Lotsa kasserts about referencedn...

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

details:   https://anonhg.NetBSD.org/src/rev/d9af4bdcd812
branches:  trunk
changeset: 366246:d9af4bdcd812
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Aug 27 14:13:16 2018 +0000

description:
Lotsa kasserts about referencedness of frences.

diffstat:

 sys/external/bsd/drm2/linux/linux_fence.c |  47 +++++++++++++++++++++++++++++-
 1 files changed, 45 insertions(+), 2 deletions(-)

diffs (196 lines):

diff -r cc2e23b9117b -r d9af4bdcd812 sys/external/bsd/drm2/linux/linux_fence.c
--- a/sys/external/bsd/drm2/linux/linux_fence.c Mon Aug 27 14:13:00 2018 +0000
+++ b/sys/external/bsd/drm2/linux/linux_fence.c Mon Aug 27 14:13:16 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: linux_fence.c,v 1.5 2018/08/27 14:01:01 riastradh Exp $        */
+/*     $NetBSD: linux_fence.c,v 1.6 2018/08/27 14:13:16 riastradh Exp $        */
 
 /*-
  * Copyright (c) 2018 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: linux_fence.c,v 1.5 2018/08/27 14:01:01 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: linux_fence.c,v 1.6 2018/08/27 14:13:16 riastradh Exp $");
 
 #include <sys/atomic.h>
 #include <sys/condvar.h>
@@ -44,6 +44,19 @@
 #include <linux/spinlock.h>
 
 /*
+ * fence_referenced_p(fence)
+ *
+ *     True if fence has a positive reference count.  True after
+ *     fence_init; after the last fence_put, this becomes false.
+ */
+static inline bool
+fence_referenced_p(struct fence *fence)
+{
+
+       return kref_referenced_p(&fence->refcount);
+}
+
+/*
  * fence_init(fence, ops, lock, context, seqno)
  *
  *     Initialize fence.  Caller should call fence_destroy when done,
@@ -74,6 +87,8 @@
 fence_destroy(struct fence *fence)
 {
 
+       KASSERT(!fence_referenced_p(fence));
+
        KASSERT(TAILQ_EMPTY(&fence->f_callbacks));
        cv_destroy(&fence->f_cv);
 }
@@ -83,6 +98,8 @@
 {
        struct fence *fence = container_of(rcu, struct fence, f_rcu);
 
+       KASSERT(!fence_referenced_p(fence));
+
        fence_destroy(fence);
        kfree(fence);
 }
@@ -103,6 +120,8 @@
 fence_free(struct fence *fence)
 {
 
+       KASSERT(!fence_referenced_p(fence));
+
        call_rcu(&fence->f_rcu, &fence_free_cb);
 }
 
@@ -176,6 +195,8 @@
 {
        struct fence *fence = container_of(refcount, struct fence, refcount);
 
+       KASSERT(!fence_referenced_p(fence));
+
        if (fence->ops->release)
                (*fence->ops->release)(fence);
        else
@@ -192,6 +213,7 @@
 fence_put(struct fence *fence)
 {
 
+       KASSERT(fence_referenced_p(fence));
        kref_put(&fence->refcount, &fence_release);
 }
 
@@ -210,6 +232,7 @@
 fence_ensure_signal_enabled(struct fence *fence)
 {
 
+       KASSERT(fence_referenced_p(fence));
        KASSERT(spin_is_locked(fence->lock));
 
        /* If the fence was already signalled, fail with -ENOENT.  */
@@ -251,6 +274,8 @@
 {
        int ret;
 
+       KASSERT(fence_referenced_p(fence));
+
        /* Optimistically try to skip the lock if it's already signalled.  */
        if (fence->flags & (1u << FENCE_FLAG_SIGNALED_BIT)) {
                ret = -ENOENT;
@@ -288,6 +313,8 @@
 {
        bool onqueue;
 
+       KASSERT(fence_referenced_p(fence));
+
        spin_lock(fence->lock);
        onqueue = fcb->fcb_onqueue;
        if (onqueue) {
@@ -311,6 +338,8 @@
 fence_enable_sw_signaling(struct fence *fence)
 {
 
+       KASSERT(fence_referenced_p(fence));
+
        spin_lock(fence->lock);
        (void)fence_ensure_signal_enabled(fence);
        spin_unlock(fence->lock);
@@ -330,6 +359,8 @@
 {
        bool signaled;
 
+       KASSERT(fence_referenced_p(fence));
+
        spin_lock(fence->lock);
        signaled = fence_is_signaled_locked(fence);
        spin_unlock(fence->lock);
@@ -347,6 +378,7 @@
 fence_is_signaled_locked(struct fence *fence)
 {
 
+       KASSERT(fence_referenced_p(fence));
        KASSERT(spin_is_locked(fence->lock));
 
        /* Check whether we already set the signalled bit.  */
@@ -383,6 +415,8 @@
 {
        int ret;
 
+       KASSERT(fence_referenced_p(fence));
+
        spin_lock(fence->lock);
        ret = fence_signal_locked(fence);
        spin_unlock(fence->lock);
@@ -401,6 +435,7 @@
 {
        struct fence_cb *fcb, *next;
 
+       KASSERT(fence_referenced_p(fence));
        KASSERT(spin_is_locked(fence->lock));
 
        /* If it's been signalled, fail; otherwise set the signalled bit.  */
@@ -435,6 +470,8 @@
 {
        struct wait_any *cb = container_of(fcb, struct wait_any, fcb);
 
+       KASSERT(fence_referenced_p(fence));
+
        mutex_enter(&cb->common->lock);
        cb->common->done = true;
        cv_broadcast(&cb->common->cv);
@@ -472,6 +509,7 @@
        /* Add a callback to each of the fences, or stop here if we can't.  */
        for (i = 0; i < nfences; i++) {
                cb[i].common = &common;
+               KASSERT(fence_referenced_p(fences[i]));
                ret = fence_add_callback(fences[i], &cb[i].fcb, &wait_any_cb);
                if (ret)
                        goto out1;
@@ -559,8 +597,10 @@
 fence_wait_timeout(struct fence *fence, bool intr, long timeout)
 {
 
+       KASSERT(fence_referenced_p(fence));
        KASSERT(timeout >= 0);
        KASSERT(timeout < MAX_SCHEDULE_TIMEOUT);
+
        return (*fence->ops->wait)(fence, intr, timeout);
 }
 
@@ -577,6 +617,8 @@
 {
        long ret;
 
+       KASSERT(fence_referenced_p(fence));
+
        ret = (*fence->ops->wait)(fence, intr, MAX_SCHEDULE_TIMEOUT);
        KASSERT(ret != 0);
 
@@ -600,6 +642,7 @@
        kmutex_t *lock = &fence->lock->sl_lock;
        long ret = 0;
 
+       KASSERT(fence_referenced_p(fence));
        KASSERT(timeout >= 0);
        KASSERT(timeout <= MAX_SCHEDULE_TIMEOUT);