[PATCH v2 6/6] dma-buf/sw_sync: de-stage SW_SYNC

Gustavo Padovan gustavo at padovan.org
Mon Aug 8 21:24:22 UTC 2016


From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>

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 at collabora.co.uk>
---
 drivers/dma-buf/Kconfig              |  13 ++
 drivers/dma-buf/Makefile             |   1 +
 drivers/dma-buf/sw_sync.c            | 349 +++++++++++++++++++++++++++++++++++
 drivers/dma-buf/sync_debug.c         | 230 +++++++++++++++++++++++
 drivers/dma-buf/sync_debug.h         |  69 +++++++
 drivers/dma-buf/sync_trace.h         |  32 ++++
 drivers/staging/android/Kconfig      |  13 --
 drivers/staging/android/Makefile     |   1 -
 drivers/staging/android/sw_sync.c    | 349 -----------------------------------
 drivers/staging/android/sync_debug.c | 230 -----------------------
 drivers/staging/android/sync_debug.h |  69 -------
 drivers/staging/android/sync_trace.h |  32 ----
 12 files changed, 694 insertions(+), 694 deletions(-)
 create mode 100644 drivers/dma-buf/sw_sync.c
 create mode 100644 drivers/dma-buf/sync_debug.c
 create mode 100644 drivers/dma-buf/sync_debug.h
 create mode 100644 drivers/dma-buf/sync_trace.h
 delete mode 100644 drivers/staging/android/sw_sync.c
 delete mode 100644 drivers/staging/android/sync_debug.c
 delete mode 100644 drivers/staging/android/sync_debug.h
 delete mode 100644 drivers/staging/android/sync_trace.h

diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig
index 25bcfa0..2585821 100644
--- a/drivers/dma-buf/Kconfig
+++ b/drivers/dma-buf/Kconfig
@@ -17,4 +17,17 @@ config SYNC_FILE
 	  Files fds, to the DRM driver for example. More details at
 	  Documentation/sync_file.txt.
 
+config SW_SYNC
+	bool "Sync File Validation Framework"
+	default n
+	depends on SYNC_FILE
+	depends on DEBUG_FS
+	---help---
+	  A sync object driver that uses a 32bit counter to coordinate
+	  synchronization.  Useful when there is no hardware primitive backing
+	  the synchronization.
+
+	  WARNING: improper use of this can result in deadlocking kernel
+	  drivers from userspace. Intended for test and debug only.
+
 endmenu
diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile
index f353db2..210a10b 100644
--- a/drivers/dma-buf/Makefile
+++ b/drivers/dma-buf/Makefile
@@ -1,2 +1,3 @@
 obj-y := dma-buf.o fence.o reservation.o seqno-fence.o fence-array.o
 obj-$(CONFIG_SYNC_FILE)		+= sync_file.o
+obj-$(CONFIG_SW_SYNC)		+= sw_sync.o sync_debug.o
diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
new file mode 100644
index 0000000..2ac5608
--- /dev/null
+++ b/drivers/dma-buf/sw_sync.c
@@ -0,0 +1,349 @@
+/*
+ * Sync File validation framework
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/sync_file.h>
+
+#include "sync_debug.h"
+
+#define CREATE_TRACE_POINTS
+#include "sync_trace.h"
+
+/*
+ * SW SYNC validation framework
+ *
+ * A sync object driver that uses a 32bit counter to coordinate
+ * synchronization.  Useful when there is no hardware primitive backing
+ * the synchronization.
+ *
+ * To start the framework just open:
+ *
+ * <debugfs>/sync/sw_sync
+ *
+ * That will create a sync timeline, all fences created under this timeline
+ * file descriptor will belong to the this timeline.
+ *
+ * The 'sw_sync' file can be opened many times as to create different
+ * timelines.
+ *
+ * Fences can be created with SW_SYNC_IOC_CREATE_FENCE ioctl with struct
+ * sw_sync_ioctl_create_fence as parameter.
+ *
+ * To increment the timeline counter SW_SYNC_IOC_INC ioctl should be used
+ * with the increment as u32. This will update the last signaled value
+ * from the timeline and signal any fence that has seqno, smaller of equal
+ * it.
+ *
+ * struct sw_sync_ioctl_create_fence
+ * @value:	the seqno to initiate the fence with
+ * @name:	the name of the new sync point
+ * @fence:	return the fd of the new sync_file with the created fence
+ */
+struct sw_sync_create_fence_data {
+	__u32	value;
+	char	name[32];
+	__s32	fence; /* fd of new fence */
+};
+
+#define SW_SYNC_IOC_MAGIC	'W'
+
+#define SW_SYNC_IOC_CREATE_FENCE	_IOWR(SW_SYNC_IOC_MAGIC, 0,\
+		struct sw_sync_create_fence_data)
+
+#define SW_SYNC_IOC_INC			_IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
+
+static const struct fence_ops timeline_fence_ops;
+
+static inline struct sync_pt *fence_to_sync_pt(struct fence *fence)
+{
+	if (fence->ops != &timeline_fence_ops)
+		return NULL;
+	return container_of(fence, struct sync_pt, base);
+}
+
+struct sync_timeline *sync_timeline_create(const char *name)
+{
+	struct sync_timeline *obj;
+
+	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
+	if (!obj)
+		return NULL;
+
+	kref_init(&obj->kref);
+	obj->context = fence_context_alloc(1);
+	strlcpy(obj->name, name, sizeof(obj->name));
+
+	INIT_LIST_HEAD(&obj->child_list_head);
+	INIT_LIST_HEAD(&obj->active_list_head);
+	spin_lock_init(&obj->child_list_lock);
+
+	sync_timeline_debug_add(obj);
+
+	return obj;
+}
+
+static void sync_timeline_free(struct kref *kref)
+{
+	struct sync_timeline *obj =
+		container_of(kref, struct sync_timeline, kref);
+
+	sync_timeline_debug_remove(obj);
+
+	kfree(obj);
+}
+
+static void sync_timeline_get(struct sync_timeline *obj)
+{
+	kref_get(&obj->kref);
+}
+
+static void sync_timeline_put(struct sync_timeline *obj)
+{
+	kref_put(&obj->kref, sync_timeline_free);
+}
+
+static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
+{
+	unsigned long flags;
+	struct sync_pt *pt, *next;
+
+	trace_sync_timeline(obj);
+
+	spin_lock_irqsave(&obj->child_list_lock, flags);
+
+	obj->value += inc;
+
+	list_for_each_entry_safe(pt, next, &obj->active_list_head,
+				 active_list) {
+		if (fence_is_signaled_locked(&pt->base))
+			list_del_init(&pt->active_list);
+	}
+
+	spin_unlock_irqrestore(&obj->child_list_lock, flags);
+}
+
+static struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size,
+			     unsigned int value)
+{
+	unsigned long flags;
+	struct sync_pt *pt;
+
+	if (size < sizeof(*pt))
+		return NULL;
+
+	pt = kzalloc(size, GFP_KERNEL);
+	if (!pt)
+		return NULL;
+
+	spin_lock_irqsave(&obj->child_list_lock, flags);
+	sync_timeline_get(obj);
+	fence_init(&pt->base, &timeline_fence_ops, &obj->child_list_lock,
+		   obj->context, value);
+	list_add_tail(&pt->child_list, &obj->child_list_head);
+	INIT_LIST_HEAD(&pt->active_list);
+	spin_unlock_irqrestore(&obj->child_list_lock, flags);
+	return pt;
+}
+
+static const char *timeline_fence_get_driver_name(struct fence *fence)
+{
+	return "sw_sync";
+}
+
+static const char *timeline_fence_get_timeline_name(struct fence *fence)
+{
+	struct sync_timeline *parent = fence_parent(fence);
+
+	return parent->name;
+}
+
+static void timeline_fence_release(struct fence *fence)
+{
+	struct sync_pt *pt = fence_to_sync_pt(fence);
+	struct sync_timeline *parent = fence_parent(fence);
+	unsigned long flags;
+
+	spin_lock_irqsave(fence->lock, flags);
+	list_del(&pt->child_list);
+	if (!list_empty(&pt->active_list))
+		list_del(&pt->active_list);
+	spin_unlock_irqrestore(fence->lock, flags);
+
+	sync_timeline_put(parent);
+	fence_free(fence);
+}
+
+static bool timeline_fence_signaled(struct fence *fence)
+{
+	struct sync_timeline *parent = fence_parent(fence);
+
+	return (fence->seqno > parent->value) ? false : true;
+}
+
+static bool timeline_fence_enable_signaling(struct fence *fence)
+{
+	struct sync_pt *pt = fence_to_sync_pt(fence);
+	struct sync_timeline *parent = fence_parent(fence);
+
+	if (timeline_fence_signaled(fence))
+		return false;
+
+	list_add_tail(&pt->active_list, &parent->active_list_head);
+	return true;
+}
+
+static void timeline_fence_value_str(struct fence *fence,
+				    char *str, int size)
+{
+	snprintf(str, size, "%d", fence->seqno);
+}
+
+static void timeline_fence_timeline_value_str(struct fence *fence,
+					     char *str, int size)
+{
+	struct sync_timeline *parent = fence_parent(fence);
+
+	snprintf(str, size, "%d", parent->value);
+}
+
+static const struct fence_ops timeline_fence_ops = {
+	.get_driver_name = timeline_fence_get_driver_name,
+	.get_timeline_name = timeline_fence_get_timeline_name,
+	.enable_signaling = timeline_fence_enable_signaling,
+	.signaled = timeline_fence_signaled,
+	.wait = fence_default_wait,
+	.release = timeline_fence_release,
+	.fence_value_str = timeline_fence_value_str,
+	.timeline_value_str = timeline_fence_timeline_value_str,
+};
+
+/*
+ * *WARNING*
+ *
+ * improper use of this can result in deadlocking kernel drivers from userspace.
+ */
+
+/* opening sw_sync create a new sync obj */
+static int sw_sync_debugfs_open(struct inode *inode, struct file *file)
+{
+	struct sync_timeline *obj;
+	char task_comm[TASK_COMM_LEN];
+
+	get_task_comm(task_comm, current);
+
+	obj = sync_timeline_create(task_comm);
+	if (!obj)
+		return -ENOMEM;
+
+	file->private_data = obj;
+
+	return 0;
+}
+
+static int sw_sync_debugfs_release(struct inode *inode, struct file *file)
+{
+	struct sync_timeline *obj = file->private_data;
+
+	smp_wmb();
+
+	sync_timeline_put(obj);
+	return 0;
+}
+
+static long sw_sync_ioctl_create_fence(struct sync_timeline *obj,
+				       unsigned long arg)
+{
+	int fd = get_unused_fd_flags(O_CLOEXEC);
+	int err;
+	struct sync_pt *pt;
+	struct sync_file *sync_file;
+	struct sw_sync_create_fence_data data;
+
+	if (fd < 0)
+		return fd;
+
+	if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
+		err = -EFAULT;
+		goto err;
+	}
+
+	pt = sync_pt_create(obj, sizeof(*pt), data.value);
+	if (!pt) {
+		err = -ENOMEM;
+		goto err;
+	}
+
+	sync_file = sync_file_create(&pt->base);
+	if (!sync_file) {
+		fence_put(&pt->base);
+		err = -ENOMEM;
+		goto err;
+	}
+
+	data.fence = fd;
+	if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
+		fput(sync_file->file);
+		err = -EFAULT;
+		goto err;
+	}
+
+	fd_install(fd, sync_file->file);
+
+	return 0;
+
+err:
+	put_unused_fd(fd);
+	return err;
+}
+
+static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg)
+{
+	u32 value;
+
+	if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
+		return -EFAULT;
+
+	sync_timeline_signal(obj, value);
+
+	return 0;
+}
+
+static long sw_sync_ioctl(struct file *file, unsigned int cmd,
+			  unsigned long arg)
+{
+	struct sync_timeline *obj = file->private_data;
+
+	switch (cmd) {
+	case SW_SYNC_IOC_CREATE_FENCE:
+		return sw_sync_ioctl_create_fence(obj, arg);
+
+	case SW_SYNC_IOC_INC:
+		return sw_sync_ioctl_inc(obj, arg);
+
+	default:
+		return -ENOTTY;
+	}
+}
+
+const struct file_operations sw_sync_debugfs_fops = {
+	.open           = sw_sync_debugfs_open,
+	.release        = sw_sync_debugfs_release,
+	.unlocked_ioctl = sw_sync_ioctl,
+	.compat_ioctl	= sw_sync_ioctl,
+};
diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
new file mode 100644
index 0000000..fab9520
--- /dev/null
+++ b/drivers/dma-buf/sync_debug.c
@@ -0,0 +1,230 @@
+/*
+ * Sync File validation framework and debug information
+ *
+ * Copyright (C) 2012 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/debugfs.h>
+#include "sync_debug.h"
+
+static struct dentry *dbgfs;
+
+static LIST_HEAD(sync_timeline_list_head);
+static DEFINE_SPINLOCK(sync_timeline_list_lock);
+static LIST_HEAD(sync_file_list_head);
+static DEFINE_SPINLOCK(sync_file_list_lock);
+
+void sync_timeline_debug_add(struct sync_timeline *obj)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sync_timeline_list_lock, flags);
+	list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head);
+	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+}
+
+void sync_timeline_debug_remove(struct sync_timeline *obj)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sync_timeline_list_lock, flags);
+	list_del(&obj->sync_timeline_list);
+	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+}
+
+void sync_file_debug_add(struct sync_file *sync_file)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sync_file_list_lock, flags);
+	list_add_tail(&sync_file->sync_file_list, &sync_file_list_head);
+	spin_unlock_irqrestore(&sync_file_list_lock, flags);
+}
+
+void sync_file_debug_remove(struct sync_file *sync_file)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sync_file_list_lock, flags);
+	list_del(&sync_file->sync_file_list);
+	spin_unlock_irqrestore(&sync_file_list_lock, flags);
+}
+
+static const char *sync_status_str(int status)
+{
+	if (status == 0)
+		return "signaled";
+
+	if (status > 0)
+		return "active";
+
+	return "error";
+}
+
+static void sync_print_fence(struct seq_file *s, struct fence *fence, bool show)
+{
+	int status = 1;
+	struct sync_timeline *parent = fence_parent(fence);
+
+	if (fence_is_signaled_locked(fence))
+		status = fence->status;
+
+	seq_printf(s, "  %s%sfence %s",
+		   show ? parent->name : "",
+		   show ? "_" : "",
+		   sync_status_str(status));
+
+	if (status <= 0) {
+		struct timespec64 ts64 =
+			ktime_to_timespec64(fence->timestamp);
+
+		seq_printf(s, "@%lld.%09ld", (s64)ts64.tv_sec, ts64.tv_nsec);
+	}
+
+	if (fence->ops->timeline_value_str &&
+		fence->ops->fence_value_str) {
+		char value[64];
+		bool success;
+
+		fence->ops->fence_value_str(fence, value, sizeof(value));
+		success = strlen(value);
+
+		if (success) {
+			seq_printf(s, ": %s", value);
+
+			fence->ops->timeline_value_str(fence, value,
+						       sizeof(value));
+
+			if (strlen(value))
+				seq_printf(s, " / %s", value);
+		}
+	}
+
+	seq_puts(s, "\n");
+}
+
+static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
+{
+	struct list_head *pos;
+	unsigned long flags;
+
+	seq_printf(s, "%s: %d\n", obj->name, obj->value);
+
+	spin_lock_irqsave(&obj->child_list_lock, flags);
+	list_for_each(pos, &obj->child_list_head) {
+		struct sync_pt *pt =
+			container_of(pos, struct sync_pt, child_list);
+		sync_print_fence(s, &pt->base, false);
+	}
+	spin_unlock_irqrestore(&obj->child_list_lock, flags);
+}
+
+static void sync_print_sync_file(struct seq_file *s,
+				  struct sync_file *sync_file)
+{
+	int i;
+
+	seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name,
+		   sync_status_str(atomic_read(&sync_file->status)));
+
+	for (i = 0; i < sync_file->num_fences; ++i)
+		sync_print_fence(s, sync_file->cbs[i].fence, true);
+}
+
+static int sync_debugfs_show(struct seq_file *s, void *unused)
+{
+	unsigned long flags;
+	struct list_head *pos;
+
+	seq_puts(s, "objs:\n--------------\n");
+
+	spin_lock_irqsave(&sync_timeline_list_lock, flags);
+	list_for_each(pos, &sync_timeline_list_head) {
+		struct sync_timeline *obj =
+			container_of(pos, struct sync_timeline,
+				     sync_timeline_list);
+
+		sync_print_obj(s, obj);
+		seq_puts(s, "\n");
+	}
+	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+
+	seq_puts(s, "fences:\n--------------\n");
+
+	spin_lock_irqsave(&sync_file_list_lock, flags);
+	list_for_each(pos, &sync_file_list_head) {
+		struct sync_file *sync_file =
+			container_of(pos, struct sync_file, sync_file_list);
+
+		sync_print_sync_file(s, sync_file);
+		seq_puts(s, "\n");
+	}
+	spin_unlock_irqrestore(&sync_file_list_lock, flags);
+	return 0;
+}
+
+static int sync_info_debugfs_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, sync_debugfs_show, inode->i_private);
+}
+
+static const struct file_operations sync_info_debugfs_fops = {
+	.open           = sync_info_debugfs_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release        = single_release,
+};
+
+static __init int sync_debugfs_init(void)
+{
+	dbgfs = debugfs_create_dir("sync", NULL);
+
+	/*
+	 * The debugfs files won't ever get removed and thus, there is
+	 * no need to protect it against removal races. The use of
+	 * debugfs_create_file_unsafe() is actually safe here.
+	 */
+	debugfs_create_file_unsafe("info", 0444, dbgfs, NULL,
+				   &sync_info_debugfs_fops);
+	debugfs_create_file_unsafe("sw_sync", 0644, dbgfs, NULL,
+				   &sw_sync_debugfs_fops);
+
+	return 0;
+}
+late_initcall(sync_debugfs_init);
+
+#define DUMP_CHUNK 256
+static char sync_dump_buf[64 * 1024];
+void sync_dump(void)
+{
+	struct seq_file s = {
+		.buf = sync_dump_buf,
+		.size = sizeof(sync_dump_buf) - 1,
+	};
+	int i;
+
+	sync_debugfs_show(&s, NULL);
+
+	for (i = 0; i < s.count; i += DUMP_CHUNK) {
+		if ((s.count - i) > DUMP_CHUNK) {
+			char c = s.buf[i + DUMP_CHUNK];
+
+			s.buf[i + DUMP_CHUNK] = 0;
+			pr_cont("%s", s.buf + i);
+			s.buf[i + DUMP_CHUNK] = c;
+		} else {
+			s.buf[s.count] = 0;
+			pr_cont("%s", s.buf + i);
+		}
+	}
+}
diff --git a/drivers/dma-buf/sync_debug.h b/drivers/dma-buf/sync_debug.h
new file mode 100644
index 0000000..ee3c27b
--- /dev/null
+++ b/drivers/dma-buf/sync_debug.h
@@ -0,0 +1,69 @@
+/*
+ * Sync File validation framework
+ *
+ * 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 {
+	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 {
+	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 */
diff --git a/drivers/dma-buf/sync_trace.h b/drivers/dma-buf/sync_trace.h
new file mode 100644
index 0000000..d13d59f
--- /dev/null
+++ b/drivers/dma-buf/sync_trace.h
@@ -0,0 +1,32 @@
+#undef TRACE_SYSTEM
+#define TRACE_INCLUDE_PATH ../../drivers/dma-buf
+#define TRACE_SYSTEM sync_trace
+
+#if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_SYNC_H
+
+#include "sync_debug.h"
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(sync_timeline,
+	TP_PROTO(struct sync_timeline *timeline),
+
+	TP_ARGS(timeline),
+
+	TP_STRUCT__entry(
+			__string(name, timeline->name)
+			__field(u32, value)
+	),
+
+	TP_fast_assign(
+			__assign_str(name, timeline->name);
+			__entry->value = timeline->value;
+	),
+
+	TP_printk("name=%s value=%d", __get_str(name), __entry->value)
+);
+
+#endif /* if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ) */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig
index 06e41d2..6c00d6f 100644
--- a/drivers/staging/android/Kconfig
+++ b/drivers/staging/android/Kconfig
@@ -24,19 +24,6 @@ config ANDROID_LOW_MEMORY_KILLER
 	  scripts (/init.rc), and it defines priority values with minimum free memory size
 	  for each priority.
 
-config SW_SYNC
-	bool "Software synchronization framework"
-	default n
-	depends on SYNC_FILE
-	depends on DEBUG_FS
-	---help---
-	  A sync object driver that uses a 32bit counter to coordinate
-	  synchronization.  Useful when there is no hardware primitive backing
-	  the synchronization.
-
-	  WARNING: improper use of this can result in deadlocking kernel
-	  drivers from userspace. Intended for test and debug only.
-
 source "drivers/staging/android/ion/Kconfig"
 
 endif # if ANDROID
diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile
index 7ca61b7..7ed1be7 100644
--- a/drivers/staging/android/Makefile
+++ b/drivers/staging/android/Makefile
@@ -4,4 +4,3 @@ obj-y					+= ion/
 
 obj-$(CONFIG_ASHMEM)			+= ashmem.o
 obj-$(CONFIG_ANDROID_LOW_MEMORY_KILLER)	+= lowmemorykiller.o
-obj-$(CONFIG_SW_SYNC)			+= sw_sync.o sync_debug.o
diff --git a/drivers/staging/android/sw_sync.c b/drivers/staging/android/sw_sync.c
deleted file mode 100644
index 2ac5608..0000000
--- a/drivers/staging/android/sw_sync.c
+++ /dev/null
@@ -1,349 +0,0 @@
-/*
- * Sync File validation framework
- *
- * Copyright (C) 2012 Google, Inc.
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * 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.
- *
- */
-
-#include <linux/file.h>
-#include <linux/fs.h>
-#include <linux/uaccess.h>
-#include <linux/slab.h>
-#include <linux/sync_file.h>
-
-#include "sync_debug.h"
-
-#define CREATE_TRACE_POINTS
-#include "sync_trace.h"
-
-/*
- * SW SYNC validation framework
- *
- * A sync object driver that uses a 32bit counter to coordinate
- * synchronization.  Useful when there is no hardware primitive backing
- * the synchronization.
- *
- * To start the framework just open:
- *
- * <debugfs>/sync/sw_sync
- *
- * That will create a sync timeline, all fences created under this timeline
- * file descriptor will belong to the this timeline.
- *
- * The 'sw_sync' file can be opened many times as to create different
- * timelines.
- *
- * Fences can be created with SW_SYNC_IOC_CREATE_FENCE ioctl with struct
- * sw_sync_ioctl_create_fence as parameter.
- *
- * To increment the timeline counter SW_SYNC_IOC_INC ioctl should be used
- * with the increment as u32. This will update the last signaled value
- * from the timeline and signal any fence that has seqno, smaller of equal
- * it.
- *
- * struct sw_sync_ioctl_create_fence
- * @value:	the seqno to initiate the fence with
- * @name:	the name of the new sync point
- * @fence:	return the fd of the new sync_file with the created fence
- */
-struct sw_sync_create_fence_data {
-	__u32	value;
-	char	name[32];
-	__s32	fence; /* fd of new fence */
-};
-
-#define SW_SYNC_IOC_MAGIC	'W'
-
-#define SW_SYNC_IOC_CREATE_FENCE	_IOWR(SW_SYNC_IOC_MAGIC, 0,\
-		struct sw_sync_create_fence_data)
-
-#define SW_SYNC_IOC_INC			_IOW(SW_SYNC_IOC_MAGIC, 1, __u32)
-
-static const struct fence_ops timeline_fence_ops;
-
-static inline struct sync_pt *fence_to_sync_pt(struct fence *fence)
-{
-	if (fence->ops != &timeline_fence_ops)
-		return NULL;
-	return container_of(fence, struct sync_pt, base);
-}
-
-struct sync_timeline *sync_timeline_create(const char *name)
-{
-	struct sync_timeline *obj;
-
-	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
-	if (!obj)
-		return NULL;
-
-	kref_init(&obj->kref);
-	obj->context = fence_context_alloc(1);
-	strlcpy(obj->name, name, sizeof(obj->name));
-
-	INIT_LIST_HEAD(&obj->child_list_head);
-	INIT_LIST_HEAD(&obj->active_list_head);
-	spin_lock_init(&obj->child_list_lock);
-
-	sync_timeline_debug_add(obj);
-
-	return obj;
-}
-
-static void sync_timeline_free(struct kref *kref)
-{
-	struct sync_timeline *obj =
-		container_of(kref, struct sync_timeline, kref);
-
-	sync_timeline_debug_remove(obj);
-
-	kfree(obj);
-}
-
-static void sync_timeline_get(struct sync_timeline *obj)
-{
-	kref_get(&obj->kref);
-}
-
-static void sync_timeline_put(struct sync_timeline *obj)
-{
-	kref_put(&obj->kref, sync_timeline_free);
-}
-
-static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
-{
-	unsigned long flags;
-	struct sync_pt *pt, *next;
-
-	trace_sync_timeline(obj);
-
-	spin_lock_irqsave(&obj->child_list_lock, flags);
-
-	obj->value += inc;
-
-	list_for_each_entry_safe(pt, next, &obj->active_list_head,
-				 active_list) {
-		if (fence_is_signaled_locked(&pt->base))
-			list_del_init(&pt->active_list);
-	}
-
-	spin_unlock_irqrestore(&obj->child_list_lock, flags);
-}
-
-static struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size,
-			     unsigned int value)
-{
-	unsigned long flags;
-	struct sync_pt *pt;
-
-	if (size < sizeof(*pt))
-		return NULL;
-
-	pt = kzalloc(size, GFP_KERNEL);
-	if (!pt)
-		return NULL;
-
-	spin_lock_irqsave(&obj->child_list_lock, flags);
-	sync_timeline_get(obj);
-	fence_init(&pt->base, &timeline_fence_ops, &obj->child_list_lock,
-		   obj->context, value);
-	list_add_tail(&pt->child_list, &obj->child_list_head);
-	INIT_LIST_HEAD(&pt->active_list);
-	spin_unlock_irqrestore(&obj->child_list_lock, flags);
-	return pt;
-}
-
-static const char *timeline_fence_get_driver_name(struct fence *fence)
-{
-	return "sw_sync";
-}
-
-static const char *timeline_fence_get_timeline_name(struct fence *fence)
-{
-	struct sync_timeline *parent = fence_parent(fence);
-
-	return parent->name;
-}
-
-static void timeline_fence_release(struct fence *fence)
-{
-	struct sync_pt *pt = fence_to_sync_pt(fence);
-	struct sync_timeline *parent = fence_parent(fence);
-	unsigned long flags;
-
-	spin_lock_irqsave(fence->lock, flags);
-	list_del(&pt->child_list);
-	if (!list_empty(&pt->active_list))
-		list_del(&pt->active_list);
-	spin_unlock_irqrestore(fence->lock, flags);
-
-	sync_timeline_put(parent);
-	fence_free(fence);
-}
-
-static bool timeline_fence_signaled(struct fence *fence)
-{
-	struct sync_timeline *parent = fence_parent(fence);
-
-	return (fence->seqno > parent->value) ? false : true;
-}
-
-static bool timeline_fence_enable_signaling(struct fence *fence)
-{
-	struct sync_pt *pt = fence_to_sync_pt(fence);
-	struct sync_timeline *parent = fence_parent(fence);
-
-	if (timeline_fence_signaled(fence))
-		return false;
-
-	list_add_tail(&pt->active_list, &parent->active_list_head);
-	return true;
-}
-
-static void timeline_fence_value_str(struct fence *fence,
-				    char *str, int size)
-{
-	snprintf(str, size, "%d", fence->seqno);
-}
-
-static void timeline_fence_timeline_value_str(struct fence *fence,
-					     char *str, int size)
-{
-	struct sync_timeline *parent = fence_parent(fence);
-
-	snprintf(str, size, "%d", parent->value);
-}
-
-static const struct fence_ops timeline_fence_ops = {
-	.get_driver_name = timeline_fence_get_driver_name,
-	.get_timeline_name = timeline_fence_get_timeline_name,
-	.enable_signaling = timeline_fence_enable_signaling,
-	.signaled = timeline_fence_signaled,
-	.wait = fence_default_wait,
-	.release = timeline_fence_release,
-	.fence_value_str = timeline_fence_value_str,
-	.timeline_value_str = timeline_fence_timeline_value_str,
-};
-
-/*
- * *WARNING*
- *
- * improper use of this can result in deadlocking kernel drivers from userspace.
- */
-
-/* opening sw_sync create a new sync obj */
-static int sw_sync_debugfs_open(struct inode *inode, struct file *file)
-{
-	struct sync_timeline *obj;
-	char task_comm[TASK_COMM_LEN];
-
-	get_task_comm(task_comm, current);
-
-	obj = sync_timeline_create(task_comm);
-	if (!obj)
-		return -ENOMEM;
-
-	file->private_data = obj;
-
-	return 0;
-}
-
-static int sw_sync_debugfs_release(struct inode *inode, struct file *file)
-{
-	struct sync_timeline *obj = file->private_data;
-
-	smp_wmb();
-
-	sync_timeline_put(obj);
-	return 0;
-}
-
-static long sw_sync_ioctl_create_fence(struct sync_timeline *obj,
-				       unsigned long arg)
-{
-	int fd = get_unused_fd_flags(O_CLOEXEC);
-	int err;
-	struct sync_pt *pt;
-	struct sync_file *sync_file;
-	struct sw_sync_create_fence_data data;
-
-	if (fd < 0)
-		return fd;
-
-	if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
-		err = -EFAULT;
-		goto err;
-	}
-
-	pt = sync_pt_create(obj, sizeof(*pt), data.value);
-	if (!pt) {
-		err = -ENOMEM;
-		goto err;
-	}
-
-	sync_file = sync_file_create(&pt->base);
-	if (!sync_file) {
-		fence_put(&pt->base);
-		err = -ENOMEM;
-		goto err;
-	}
-
-	data.fence = fd;
-	if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
-		fput(sync_file->file);
-		err = -EFAULT;
-		goto err;
-	}
-
-	fd_install(fd, sync_file->file);
-
-	return 0;
-
-err:
-	put_unused_fd(fd);
-	return err;
-}
-
-static long sw_sync_ioctl_inc(struct sync_timeline *obj, unsigned long arg)
-{
-	u32 value;
-
-	if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
-		return -EFAULT;
-
-	sync_timeline_signal(obj, value);
-
-	return 0;
-}
-
-static long sw_sync_ioctl(struct file *file, unsigned int cmd,
-			  unsigned long arg)
-{
-	struct sync_timeline *obj = file->private_data;
-
-	switch (cmd) {
-	case SW_SYNC_IOC_CREATE_FENCE:
-		return sw_sync_ioctl_create_fence(obj, arg);
-
-	case SW_SYNC_IOC_INC:
-		return sw_sync_ioctl_inc(obj, arg);
-
-	default:
-		return -ENOTTY;
-	}
-}
-
-const struct file_operations sw_sync_debugfs_fops = {
-	.open           = sw_sync_debugfs_open,
-	.release        = sw_sync_debugfs_release,
-	.unlocked_ioctl = sw_sync_ioctl,
-	.compat_ioctl	= sw_sync_ioctl,
-};
diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c
deleted file mode 100644
index fab9520..0000000
--- a/drivers/staging/android/sync_debug.c
+++ /dev/null
@@ -1,230 +0,0 @@
-/*
- * Sync File validation framework and debug information
- *
- * Copyright (C) 2012 Google, Inc.
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * 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.
- *
- */
-
-#include <linux/debugfs.h>
-#include "sync_debug.h"
-
-static struct dentry *dbgfs;
-
-static LIST_HEAD(sync_timeline_list_head);
-static DEFINE_SPINLOCK(sync_timeline_list_lock);
-static LIST_HEAD(sync_file_list_head);
-static DEFINE_SPINLOCK(sync_file_list_lock);
-
-void sync_timeline_debug_add(struct sync_timeline *obj)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&sync_timeline_list_lock, flags);
-	list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head);
-	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
-}
-
-void sync_timeline_debug_remove(struct sync_timeline *obj)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&sync_timeline_list_lock, flags);
-	list_del(&obj->sync_timeline_list);
-	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
-}
-
-void sync_file_debug_add(struct sync_file *sync_file)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&sync_file_list_lock, flags);
-	list_add_tail(&sync_file->sync_file_list, &sync_file_list_head);
-	spin_unlock_irqrestore(&sync_file_list_lock, flags);
-}
-
-void sync_file_debug_remove(struct sync_file *sync_file)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&sync_file_list_lock, flags);
-	list_del(&sync_file->sync_file_list);
-	spin_unlock_irqrestore(&sync_file_list_lock, flags);
-}
-
-static const char *sync_status_str(int status)
-{
-	if (status == 0)
-		return "signaled";
-
-	if (status > 0)
-		return "active";
-
-	return "error";
-}
-
-static void sync_print_fence(struct seq_file *s, struct fence *fence, bool show)
-{
-	int status = 1;
-	struct sync_timeline *parent = fence_parent(fence);
-
-	if (fence_is_signaled_locked(fence))
-		status = fence->status;
-
-	seq_printf(s, "  %s%sfence %s",
-		   show ? parent->name : "",
-		   show ? "_" : "",
-		   sync_status_str(status));
-
-	if (status <= 0) {
-		struct timespec64 ts64 =
-			ktime_to_timespec64(fence->timestamp);
-
-		seq_printf(s, "@%lld.%09ld", (s64)ts64.tv_sec, ts64.tv_nsec);
-	}
-
-	if (fence->ops->timeline_value_str &&
-		fence->ops->fence_value_str) {
-		char value[64];
-		bool success;
-
-		fence->ops->fence_value_str(fence, value, sizeof(value));
-		success = strlen(value);
-
-		if (success) {
-			seq_printf(s, ": %s", value);
-
-			fence->ops->timeline_value_str(fence, value,
-						       sizeof(value));
-
-			if (strlen(value))
-				seq_printf(s, " / %s", value);
-		}
-	}
-
-	seq_puts(s, "\n");
-}
-
-static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
-{
-	struct list_head *pos;
-	unsigned long flags;
-
-	seq_printf(s, "%s: %d\n", obj->name, obj->value);
-
-	spin_lock_irqsave(&obj->child_list_lock, flags);
-	list_for_each(pos, &obj->child_list_head) {
-		struct sync_pt *pt =
-			container_of(pos, struct sync_pt, child_list);
-		sync_print_fence(s, &pt->base, false);
-	}
-	spin_unlock_irqrestore(&obj->child_list_lock, flags);
-}
-
-static void sync_print_sync_file(struct seq_file *s,
-				  struct sync_file *sync_file)
-{
-	int i;
-
-	seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name,
-		   sync_status_str(atomic_read(&sync_file->status)));
-
-	for (i = 0; i < sync_file->num_fences; ++i)
-		sync_print_fence(s, sync_file->cbs[i].fence, true);
-}
-
-static int sync_debugfs_show(struct seq_file *s, void *unused)
-{
-	unsigned long flags;
-	struct list_head *pos;
-
-	seq_puts(s, "objs:\n--------------\n");
-
-	spin_lock_irqsave(&sync_timeline_list_lock, flags);
-	list_for_each(pos, &sync_timeline_list_head) {
-		struct sync_timeline *obj =
-			container_of(pos, struct sync_timeline,
-				     sync_timeline_list);
-
-		sync_print_obj(s, obj);
-		seq_puts(s, "\n");
-	}
-	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
-
-	seq_puts(s, "fences:\n--------------\n");
-
-	spin_lock_irqsave(&sync_file_list_lock, flags);
-	list_for_each(pos, &sync_file_list_head) {
-		struct sync_file *sync_file =
-			container_of(pos, struct sync_file, sync_file_list);
-
-		sync_print_sync_file(s, sync_file);
-		seq_puts(s, "\n");
-	}
-	spin_unlock_irqrestore(&sync_file_list_lock, flags);
-	return 0;
-}
-
-static int sync_info_debugfs_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, sync_debugfs_show, inode->i_private);
-}
-
-static const struct file_operations sync_info_debugfs_fops = {
-	.open           = sync_info_debugfs_open,
-	.read           = seq_read,
-	.llseek         = seq_lseek,
-	.release        = single_release,
-};
-
-static __init int sync_debugfs_init(void)
-{
-	dbgfs = debugfs_create_dir("sync", NULL);
-
-	/*
-	 * The debugfs files won't ever get removed and thus, there is
-	 * no need to protect it against removal races. The use of
-	 * debugfs_create_file_unsafe() is actually safe here.
-	 */
-	debugfs_create_file_unsafe("info", 0444, dbgfs, NULL,
-				   &sync_info_debugfs_fops);
-	debugfs_create_file_unsafe("sw_sync", 0644, dbgfs, NULL,
-				   &sw_sync_debugfs_fops);
-
-	return 0;
-}
-late_initcall(sync_debugfs_init);
-
-#define DUMP_CHUNK 256
-static char sync_dump_buf[64 * 1024];
-void sync_dump(void)
-{
-	struct seq_file s = {
-		.buf = sync_dump_buf,
-		.size = sizeof(sync_dump_buf) - 1,
-	};
-	int i;
-
-	sync_debugfs_show(&s, NULL);
-
-	for (i = 0; i < s.count; i += DUMP_CHUNK) {
-		if ((s.count - i) > DUMP_CHUNK) {
-			char c = s.buf[i + DUMP_CHUNK];
-
-			s.buf[i + DUMP_CHUNK] = 0;
-			pr_cont("%s", s.buf + i);
-			s.buf[i + DUMP_CHUNK] = c;
-		} else {
-			s.buf[s.count] = 0;
-			pr_cont("%s", s.buf + i);
-		}
-	}
-}
diff --git a/drivers/staging/android/sync_debug.h b/drivers/staging/android/sync_debug.h
deleted file mode 100644
index ee3c27b..0000000
--- a/drivers/staging/android/sync_debug.h
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Sync File validation framework
- *
- * 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 {
-	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 {
-	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 */
diff --git a/drivers/staging/android/sync_trace.h b/drivers/staging/android/sync_trace.h
deleted file mode 100644
index ea485f7..0000000
--- a/drivers/staging/android/sync_trace.h
+++ /dev/null
@@ -1,32 +0,0 @@
-#undef TRACE_SYSTEM
-#define TRACE_INCLUDE_PATH ../../drivers/staging/android
-#define TRACE_SYSTEM sync_trace
-
-#if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ)
-#define _TRACE_SYNC_H
-
-#include "sync_debug.h"
-#include <linux/tracepoint.h>
-
-TRACE_EVENT(sync_timeline,
-	TP_PROTO(struct sync_timeline *timeline),
-
-	TP_ARGS(timeline),
-
-	TP_STRUCT__entry(
-			__string(name, timeline->name)
-			__field(u32, value)
-	),
-
-	TP_fast_assign(
-			__assign_str(name, timeline->name);
-			__entry->value = timeline->value;
-	),
-
-	TP_printk("name=%s value=%d", __get_str(name), __entry->value)
-);
-
-#endif /* if !defined(_TRACE_SYNC_H) || defined(TRACE_HEADER_MULTI_READ) */
-
-/* This part must be outside protection */
-#include <trace/define_trace.h>
-- 
2.5.5



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