dma-buf/sw_sync: de-stage SW_SYNC

SW_SYNC allows to run tests on the sync_file framework via debugfs on

<debugfs>/sync/sw_sync

Opening and closing the file triggers creation and release of a sync
timeline. To create fences on this timeline the SW_SYNC_IOC_CREATE_FENCE
ioctl should be used. To increment the timeline value use SW_SYNC_IOC_INC.

Also it exports Sync information on

<debugfs>/sync/info

Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 84 insertions, 0 deletions

diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
new file mode 100644
index 000000000000..d269aa6783aa
--- /dev/null
+++ b/drivers/dma-buf/sync_debug.h
@@ -0,0 +1,84 @@
+/*
+ * Sync File validation framework and debug infomation
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _LINUX_SYNC_H
+#define _LINUX_SYNC_H
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/fence.h>
+
+#include <linux/sync_file.h>
+#include <uapi/linux/sync_file.h>
+
+/**
+ * struct sync_timeline - sync object
+ * @kref:		reference count on fence.
+ * @name:		name of the sync_timeline. Useful for debugging
+ * @child_list_head:	list of children sync_pts for this sync_timeline
+ * @child_list_lock:	lock protecting @child_list_head and fence.status
+ * @active_list_head:	list of active (unsignaled/errored) sync_pts
+ * @sync_timeline_list:	membership in global sync_timeline_list
+ */
+struct sync_timeline {
+	struct kref		kref;
+	char			name[32];
+
+	/* protected by child_list_lock */
+	u64			context;
+	int			value;
+
+	struct list_head	child_list_head;
+	spinlock_t		child_list_lock;
+
+	struct list_head	active_list_head;
+
+	struct list_head	sync_timeline_list;
+};
+
+static inline struct sync_timeline *fence_parent(struct fence *fence)
+{
+	return container_of(fence->lock, struct sync_timeline,
+			    child_list_lock);
+}
+
+/**
+ * struct sync_pt - sync_pt object
+ * @base: base fence object
+ * @child_list: sync timeline child's list
+ * @active_list: sync timeline active child's list
+ */
+struct sync_pt {
+	struct fence base;
+	struct list_head child_list;
+	struct list_head active_list;
+};
+
+#ifdef CONFIG_SW_SYNC
+
+extern const struct file_operations sw_sync_debugfs_fops;
+
+void sync_timeline_debug_add(struct sync_timeline *obj);
+void sync_timeline_debug_remove(struct sync_timeline *obj);
+void sync_file_debug_add(struct sync_file *fence);
+void sync_file_debug_remove(struct sync_file *fence);
+void sync_dump(void);
+
+#else
+# define sync_timeline_debug_add(obj)
+# define sync_timeline_debug_remove(obj)
+# define sync_file_debug_add(fence)
+# define sync_file_debug_remove(fence)
+# define sync_dump()
+#endif
+
+#endif /* _LINUX_SYNC_H */