BUG_ON(dmabuf->vmapping_counter);
/*
- * Any fences that a dma-buf poll can wait on should be signaled
- * before releasing dma-buf. This is the responsibility of each
- * driver that uses the reservation objects.
- *
- * If you hit this BUG() it means someone dropped their ref to the
- * dma-buf while still having pending operation to the buffer.
+ * If you hit this BUG() it could mean:
+ * * There's a file reference imbalance in dma_buf_poll / dma_buf_poll_cb or somewhere else
+ * * dmabuf->cb_in/out.active are non-0 despite no pending fence callback
*/
- BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active);
+ BUG_ON(dmabuf->cb_in.active || dmabuf->cb_out.active);
dma_buf_stats_teardown(dmabuf);
dmabuf->ops->release(dmabuf);
if (dmabuf->resv == (struct dma_resv *)&dmabuf[1])
dma_resv_fini(dmabuf->resv);
+ WARN_ON(!list_empty(&dmabuf->attachments));
module_put(dmabuf->owner);
kfree(dmabuf->name);
kfree(dmabuf);
static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
{
struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb;
+ struct dma_buf *dmabuf = container_of(dcb->poll, struct dma_buf, poll);
unsigned long flags;
spin_lock_irqsave(&dcb->poll->lock, flags);
wake_up_locked_poll(dcb->poll, dcb->active);
dcb->active = 0;
spin_unlock_irqrestore(&dcb->poll->lock, flags);
+ dma_fence_put(fence);
+ /* Paired with get_file in dma_buf_poll */
+ fput(dmabuf->file);
+}
+
+static bool dma_buf_poll_add_cb(struct dma_resv *resv, bool write,
+ struct dma_buf_poll_cb_t *dcb)
+{
+ struct dma_resv_iter cursor;
+ struct dma_fence *fence;
+ int r;
+
+ dma_resv_for_each_fence(&cursor, resv, write, fence) {
+ dma_fence_get(fence);
+ r = dma_fence_add_callback(fence, &dcb->cb, dma_buf_poll_cb);
+ if (!r)
+ return true;
+ dma_fence_put(fence);
+ }
+
+ return false;
}
static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
{
struct dma_buf *dmabuf;
struct dma_resv *resv;
- struct dma_resv_list *fobj;
- struct dma_fence *fence_excl;
__poll_t events;
- unsigned shared_count, seq;
dmabuf = file->private_data;
if (!dmabuf || !dmabuf->resv)
if (!events)
return 0;
-retry:
- seq = read_seqcount_begin(&resv->seq);
- rcu_read_lock();
+ dma_resv_lock(resv, NULL);
- fobj = rcu_dereference(resv->fence);
- if (fobj)
- shared_count = fobj->shared_count;
- else
- shared_count = 0;
- fence_excl = dma_resv_excl_fence(resv);
- if (read_seqcount_retry(&resv->seq, seq)) {
- rcu_read_unlock();
- goto retry;
- }
-
- if (fence_excl && (!(events & EPOLLOUT) || shared_count == 0)) {
- struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl;
- __poll_t pevents = EPOLLIN;
-
- if (shared_count == 0)
- pevents |= EPOLLOUT;
+ if (events & EPOLLOUT) {
+ struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_out;
+ /* Check that callback isn't busy */
spin_lock_irq(&dmabuf->poll.lock);
- if (dcb->active) {
- dcb->active |= pevents;
- events &= ~pevents;
- } else
- dcb->active = pevents;
+ if (dcb->active)
+ events &= ~EPOLLOUT;
+ else
+ dcb->active = EPOLLOUT;
spin_unlock_irq(&dmabuf->poll.lock);
- if (events & pevents) {
- if (!dma_fence_get_rcu(fence_excl)) {
- /* force a recheck */
- events &= ~pevents;
- dma_buf_poll_cb(NULL, &dcb->cb);
- } else if (!dma_fence_add_callback(fence_excl, &dcb->cb,
- dma_buf_poll_cb)) {
- events &= ~pevents;
- dma_fence_put(fence_excl);
- } else {
- /*
- * No callback queued, wake up any additional
- * waiters.
- */
- dma_fence_put(fence_excl);
+ if (events & EPOLLOUT) {
+ /* Paired with fput in dma_buf_poll_cb */
+ get_file(dmabuf->file);
+
+ if (!dma_buf_poll_add_cb(resv, true, dcb))
+ /* No callback queued, wake up any other waiters */
dma_buf_poll_cb(NULL, &dcb->cb);
- }
+ else
+ events &= ~EPOLLOUT;
}
}
- if ((events & EPOLLOUT) && shared_count > 0) {
- struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared;
- int i;
+ if (events & EPOLLIN) {
+ struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_in;
- /* Only queue a new callback if no event has fired yet */
+ /* Check that callback isn't busy */
spin_lock_irq(&dmabuf->poll.lock);
if (dcb->active)
- events &= ~EPOLLOUT;
+ events &= ~EPOLLIN;
else
- dcb->active = EPOLLOUT;
+ dcb->active = EPOLLIN;
spin_unlock_irq(&dmabuf->poll.lock);
- if (!(events & EPOLLOUT))
- goto out;
+ if (events & EPOLLIN) {
+ /* Paired with fput in dma_buf_poll_cb */
+ get_file(dmabuf->file);
- for (i = 0; i < shared_count; ++i) {
- struct dma_fence *fence = rcu_dereference(fobj->shared[i]);
-
- if (!dma_fence_get_rcu(fence)) {
- /*
- * fence refcount dropped to zero, this means
- * that fobj has been freed
- *
- * call dma_buf_poll_cb and force a recheck!
- */
- events &= ~EPOLLOUT;
+ if (!dma_buf_poll_add_cb(resv, false, dcb))
+ /* No callback queued, wake up any other waiters */
dma_buf_poll_cb(NULL, &dcb->cb);
- break;
- }
- if (!dma_fence_add_callback(fence, &dcb->cb,
- dma_buf_poll_cb)) {
- dma_fence_put(fence);
- events &= ~EPOLLOUT;
- break;
- }
- dma_fence_put(fence);
+ else
+ events &= ~EPOLLIN;
}
-
- /* No callback queued, wake up any additional waiters. */
- if (i == shared_count)
- dma_buf_poll_cb(NULL, &dcb->cb);
}
-out:
- rcu_read_unlock();
+ dma_resv_unlock(resv);
return events;
}
dmabuf->owner = exp_info->owner;
spin_lock_init(&dmabuf->name_lock);
init_waitqueue_head(&dmabuf->poll);
- dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll;
- dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0;
+ dmabuf->cb_in.poll = dmabuf->cb_out.poll = &dmabuf->poll;
+ dmabuf->cb_in.active = dmabuf->cb_out.active = 0;
if (!resv) {
resv = (struct dma_resv *)&dmabuf[1];
{
struct dma_buf *buf_obj;
struct dma_buf_attachment *attach_obj;
- struct dma_resv *robj;
- struct dma_resv_list *fobj;
+ struct dma_resv_iter cursor;
struct dma_fence *fence;
- int count = 0, attach_count, shared_count, i;
+ int count = 0, attach_count;
size_t size = 0;
int ret;
buf_obj->name ?: "");
spin_unlock(&buf_obj->name_lock);
- robj = buf_obj->resv;
- fence = dma_resv_excl_fence(robj);
- if (fence)
- seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n",
- fence->ops->get_driver_name(fence),
- fence->ops->get_timeline_name(fence),
- dma_fence_is_signaled(fence) ? "" : "un");
-
- fobj = rcu_dereference_protected(robj->fence,
- dma_resv_held(robj));
- shared_count = fobj ? fobj->shared_count : 0;
- for (i = 0; i < shared_count; i++) {
- fence = rcu_dereference_protected(fobj->shared[i],
- dma_resv_held(robj));
- seq_printf(s, "\tShared fence: %s %s %ssignalled\n",
+ dma_resv_for_each_fence(&cursor, buf_obj->resv, true, fence) {
+ seq_printf(s, "\t%s fence: %s %s %ssignalled\n",
+ dma_resv_iter_is_exclusive(&cursor) ?
+ "Exclusive" : "Shared",
fence->ops->get_driver_name(fence),
fence->ops->get_timeline_name(fence),
dma_fence_is_signaled(fence) ? "" : "un");
projects / linux-2.6-microblaze.git / blobdiff