/*
- * drivers/base/sw_sync.c
+ * drivers/dma-buf/sw_sync.c
*
* Copyright (C) 2012 Google, Inc.
*
*
*/
-#include <linux/kernel.h>
-#include <linux/init.h>
-#include <linux/export.h>
#include <linux/file.h>
#include <linux/fs.h>
-#include <linux/miscdevice.h>
-#include <linux/syscalls.h>
#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <linux/sync_file.h>
-#include "sw_sync.h"
+#include "sync_debug.h"
-struct fence *sw_sync_pt_create(struct sw_sync_timeline *obj, u32 value)
+#define CREATE_TRACE_POINTS
+#include "trace/sync.h"
+
+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);
+}
+
+/**
+ * sync_timeline_create() - creates a sync object
+ * @name: sync_timeline name
+ *
+ * Creates a new sync_timeline. Returns the sync_timeline object or NULL in
+ * case of error.
+ */
+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);
+}
+
+/**
+ * sync_timeline_signal() - signal a status change on a sync_timeline
+ * @obj: sync_timeline to signal
+ * @inc: num to increment on timeline->value
+ *
+ * A sync implementation should call this any time one of it's fences
+ * has signaled or has an error condition.
+ */
+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);
+}
+
+/**
+ * sync_pt_create() - creates a sync pt
+ * @parent: fence's parent sync_timeline
+ * @size: size to allocate for this pt
+ * @inc: value of the fence
+ *
+ * Creates a new sync_pt as a child of @parent. @size bytes will be
+ * allocated allowing for implementation specific data to be kept after
+ * the generic sync_timeline struct. Returns the sync_pt object or
+ * NULL in case of error.
+ */
+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 sw_sync_pt *pt;
+ struct sync_pt *pt = fence_to_sync_pt(fence);
+ struct sync_timeline *parent = fence_parent(fence);
+ unsigned long flags;
- pt = (struct sw_sync_pt *)
- sync_pt_create(&obj->obj, sizeof(struct sw_sync_pt));
+ spin_lock_irqsave(fence->lock, flags);
+ list_del(&pt->child_list);
+ if (WARN_ON_ONCE(!list_empty(&pt->active_list)))
+ list_del(&pt->active_list);
+ spin_unlock_irqrestore(fence->lock, flags);
- pt->value = value;
+ sync_timeline_put(parent);
+ fence_free(fence);
+}
+
+static bool timeline_fence_signaled(struct fence *fence)
+{
+ struct sync_timeline *parent = fence_parent(fence);
- return (struct fence *)pt;
+ return (fence->seqno > parent->value) ? false : true;
}
-EXPORT_SYMBOL(sw_sync_pt_create);
-static int sw_sync_fence_has_signaled(struct fence *fence)
+static bool timeline_fence_enable_signaling(struct fence *fence)
{
- struct sw_sync_pt *pt = (struct sw_sync_pt *)fence;
- struct sw_sync_timeline *obj =
- (struct sw_sync_timeline *)fence_parent(fence);
+ struct sync_pt *pt = fence_to_sync_pt(fence);
+ struct sync_timeline *parent = fence_parent(fence);
- return (pt->value > obj->value) ? 0 : 1;
+ if (timeline_fence_signaled(fence))
+ return false;
+
+ list_add_tail(&pt->active_list, &parent->active_list_head);
+ return true;
}
-static void sw_sync_timeline_value_str(struct sync_timeline *sync_timeline,
- char *str, int size)
+static void timeline_fence_value_str(struct fence *fence,
+ char *str, int size)
{
- struct sw_sync_timeline *timeline =
- (struct sw_sync_timeline *)sync_timeline;
- snprintf(str, size, "%d", timeline->value);
+ snprintf(str, size, "%d", fence->seqno);
}
-static void sw_sync_fence_value_str(struct fence *fence, char *str, int size)
+static void timeline_fence_timeline_value_str(struct fence *fence,
+ char *str, int size)
{
- struct sw_sync_pt *pt = (struct sw_sync_pt *)fence;
+ struct sync_timeline *parent = fence_parent(fence);
- snprintf(str, size, "%d", pt->value);
+ snprintf(str, size, "%d", parent->value);
}
-static struct sync_timeline_ops sw_sync_timeline_ops = {
- .driver_name = "sw_sync",
- .has_signaled = sw_sync_fence_has_signaled,
- .timeline_value_str = sw_sync_timeline_value_str,
- .fence_value_str = sw_sync_fence_value_str,
+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,
};
-struct sw_sync_timeline *sw_sync_timeline_create(const char *name)
+/*
+ * *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 sw_sync_timeline *obj = (struct sw_sync_timeline *)
- sync_timeline_create(&sw_sync_timeline_ops,
- sizeof(struct sw_sync_timeline),
- name);
+ struct sync_timeline *obj;
+ char task_comm[TASK_COMM_LEN];
- return obj;
+ get_task_comm(task_comm, current);
+
+ obj = sync_timeline_create(task_comm);
+ if (!obj)
+ return -ENOMEM;
+
+ file->private_data = obj;
+
+ return 0;
}
-EXPORT_SYMBOL(sw_sync_timeline_create);
-void sw_sync_timeline_inc(struct sw_sync_timeline *obj, u32 inc)
+static int sw_sync_debugfs_release(struct inode *inode, struct file *file)
{
- obj->value += inc;
+ 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;
+}
- sync_timeline_signal(&obj->obj);
+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;
+ }
}
-EXPORT_SYMBOL(sw_sync_timeline_inc);
+
+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,
+};
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