* requirement is inherited from the wait-before-signal behavior required by
* the Vulkan timeline semaphore API.
*
+ * Alternatively, &DRM_IOCTL_SYNCOBJ_EVENTFD can be used to wait without
+ * blocking: an eventfd will be signaled when the syncobj is. This is useful to
+ * integrate the wait in an event loop.
+ *
*
* Import/export of syncobjs
* -------------------------
#include <linux/anon_inodes.h>
#include <linux/dma-fence-unwrap.h>
+#include <linux/eventfd.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/sched/signal.h>
static void syncobj_wait_syncobj_func(struct drm_syncobj *syncobj,
struct syncobj_wait_entry *wait);
+struct syncobj_eventfd_entry {
+ struct list_head node;
+ struct dma_fence *fence;
+ struct dma_fence_cb fence_cb;
+ struct drm_syncobj *syncobj;
+ struct eventfd_ctx *ev_fd_ctx;
+ u64 point;
+ u32 flags;
+};
+
+static void
+syncobj_eventfd_entry_func(struct drm_syncobj *syncobj,
+ struct syncobj_eventfd_entry *entry);
+
/**
* drm_syncobj_find - lookup and reference a sync object.
* @file_private: drm file private pointer
spin_unlock(&syncobj->lock);
}
+static void
+syncobj_eventfd_entry_free(struct syncobj_eventfd_entry *entry)
+{
+ eventfd_ctx_put(entry->ev_fd_ctx);
+ dma_fence_put(entry->fence);
+ /* This happens either inside the syncobj lock, or after the node has
+ * already been removed from the list.
+ */
+ list_del(&entry->node);
+ kfree(entry);
+}
+
+static void
+drm_syncobj_add_eventfd(struct drm_syncobj *syncobj,
+ struct syncobj_eventfd_entry *entry)
+{
+ spin_lock(&syncobj->lock);
+ list_add_tail(&entry->node, &syncobj->ev_fd_list);
+ syncobj_eventfd_entry_func(syncobj, entry);
+ spin_unlock(&syncobj->lock);
+}
+
/**
* drm_syncobj_add_point - add new timeline point to the syncobj
* @syncobj: sync object to add timeline point do
struct dma_fence *fence,
uint64_t point)
{
- struct syncobj_wait_entry *cur, *tmp;
+ struct syncobj_wait_entry *wait_cur, *wait_tmp;
+ struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
struct dma_fence *prev;
dma_fence_get(fence);
dma_fence_chain_init(chain, prev, fence, point);
rcu_assign_pointer(syncobj->fence, &chain->base);
- list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node)
- syncobj_wait_syncobj_func(syncobj, cur);
+ list_for_each_entry_safe(wait_cur, wait_tmp, &syncobj->cb_list, node)
+ syncobj_wait_syncobj_func(syncobj, wait_cur);
+ list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
+ syncobj_eventfd_entry_func(syncobj, ev_fd_cur);
spin_unlock(&syncobj->lock);
/* Walk the chain once to trigger garbage collection */
struct dma_fence *fence)
{
struct dma_fence *old_fence;
- struct syncobj_wait_entry *cur, *tmp;
+ struct syncobj_wait_entry *wait_cur, *wait_tmp;
+ struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
if (fence)
dma_fence_get(fence);
rcu_assign_pointer(syncobj->fence, fence);
if (fence != old_fence) {
- list_for_each_entry_safe(cur, tmp, &syncobj->cb_list, node)
- syncobj_wait_syncobj_func(syncobj, cur);
+ list_for_each_entry_safe(wait_cur, wait_tmp, &syncobj->cb_list, node)
+ syncobj_wait_syncobj_func(syncobj, wait_cur);
+ list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
+ syncobj_eventfd_entry_func(syncobj, ev_fd_cur);
}
spin_unlock(&syncobj->lock);
struct drm_syncobj *syncobj = container_of(kref,
struct drm_syncobj,
refcount);
+ struct syncobj_eventfd_entry *ev_fd_cur, *ev_fd_tmp;
+
drm_syncobj_replace_fence(syncobj, NULL);
+
+ list_for_each_entry_safe(ev_fd_cur, ev_fd_tmp, &syncobj->ev_fd_list, node)
+ syncobj_eventfd_entry_free(ev_fd_cur);
+
kfree(syncobj);
}
EXPORT_SYMBOL(drm_syncobj_free);
kref_init(&syncobj->refcount);
INIT_LIST_HEAD(&syncobj->cb_list);
+ INIT_LIST_HEAD(&syncobj->ev_fd_list);
spin_lock_init(&syncobj->lock);
if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
return ret;
}
+static void syncobj_eventfd_entry_fence_func(struct dma_fence *fence,
+ struct dma_fence_cb *cb)
+{
+ struct syncobj_eventfd_entry *entry =
+ container_of(cb, struct syncobj_eventfd_entry, fence_cb);
+
+ eventfd_signal(entry->ev_fd_ctx, 1);
+ syncobj_eventfd_entry_free(entry);
+}
+
+static void
+syncobj_eventfd_entry_func(struct drm_syncobj *syncobj,
+ struct syncobj_eventfd_entry *entry)
+{
+ int ret;
+ struct dma_fence *fence;
+
+ /* This happens inside the syncobj lock */
+ fence = dma_fence_get(rcu_dereference_protected(syncobj->fence, 1));
+ ret = dma_fence_chain_find_seqno(&fence, entry->point);
+ if (ret != 0 || !fence) {
+ dma_fence_put(fence);
+ return;
+ }
+
+ list_del_init(&entry->node);
+ entry->fence = fence;
+
+ if (entry->flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE) {
+ eventfd_signal(entry->ev_fd_ctx, 1);
+ syncobj_eventfd_entry_free(entry);
+ } else {
+ ret = dma_fence_add_callback(fence, &entry->fence_cb,
+ syncobj_eventfd_entry_fence_func);
+ if (ret == -ENOENT) {
+ eventfd_signal(entry->ev_fd_ctx, 1);
+ syncobj_eventfd_entry_free(entry);
+ }
+ }
+}
+
+int
+drm_syncobj_eventfd_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file_private)
+{
+ struct drm_syncobj_eventfd *args = data;
+ struct drm_syncobj *syncobj;
+ struct eventfd_ctx *ev_fd_ctx;
+ struct syncobj_eventfd_entry *entry;
+
+ if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ_TIMELINE))
+ return -EOPNOTSUPP;
+
+ if (args->flags & ~DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE)
+ return -EINVAL;
+
+ if (args->pad)
+ return -EINVAL;
+
+ syncobj = drm_syncobj_find(file_private, args->handle);
+ if (!syncobj)
+ return -ENOENT;
+
+ ev_fd_ctx = eventfd_ctx_fdget(args->fd);
+ if (IS_ERR(ev_fd_ctx))
+ return PTR_ERR(ev_fd_ctx);
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry) {
+ eventfd_ctx_put(ev_fd_ctx);
+ return -ENOMEM;
+ }
+ entry->syncobj = syncobj;
+ entry->ev_fd_ctx = ev_fd_ctx;
+ entry->point = args->point;
+ entry->flags = args->flags;
+
+ drm_syncobj_add_eventfd(syncobj, entry);
+ drm_syncobj_put(syncobj);
+
+ return 0;
+}
int
drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
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