staging: sync: Add synchronization framework
Sync is a framework for synchronization between multiple
drivers. Sync implementations can take advantage of hardware
synchronization built into devices like GPUs.
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Erik Gilling <konkers@android.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Clark <robclark@gmail.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: dri-devel@lists.freedesktop.org
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Erik Gilling <konkers@android.com>
[jstultz: Added commit message, moved to staging, squished minor fix in]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/staging/android/sync.c b/drivers/staging/android/sync.c
new file mode 100644
index 0000000..4a9e63d
--- /dev/null
+++ b/drivers/staging/android/sync.c
@@ -0,0 +1,525 @@
+/*
+ * drivers/base/sync.c
+ *
+ * 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/kernel.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/anon_inodes.h>
+
+#include "sync.h"
+
+static void sync_fence_signal_pt(struct sync_pt *pt);
+static int _sync_pt_has_signaled(struct sync_pt *pt);
+
+struct sync_timeline *sync_timeline_create(const struct sync_timeline_ops *ops,
+ int size, const char *name)
+{
+ struct sync_timeline *obj;
+
+ if (size < sizeof(struct sync_timeline))
+ return NULL;
+
+ obj = kzalloc(size, GFP_KERNEL);
+ if (obj == NULL)
+ return NULL;
+
+ obj->ops = ops;
+ strlcpy(obj->name, name, sizeof(obj->name));
+
+ INIT_LIST_HEAD(&obj->child_list_head);
+ spin_lock_init(&obj->child_list_lock);
+
+ INIT_LIST_HEAD(&obj->active_list_head);
+ spin_lock_init(&obj->active_list_lock);
+
+ return obj;
+}
+
+void sync_timeline_destroy(struct sync_timeline *obj)
+{
+ unsigned long flags;
+ bool needs_freeing;
+
+ spin_lock_irqsave(&obj->child_list_lock, flags);
+ obj->destroyed = true;
+ needs_freeing = list_empty(&obj->child_list_head);
+ spin_unlock_irqrestore(&obj->child_list_lock, flags);
+
+ if (needs_freeing)
+ kfree(obj);
+ else
+ sync_timeline_signal(obj);
+}
+
+static void sync_timeline_add_pt(struct sync_timeline *obj, struct sync_pt *pt)
+{
+ unsigned long flags;
+
+ pt->parent = obj;
+
+ spin_lock_irqsave(&obj->child_list_lock, flags);
+ list_add_tail(&pt->child_list, &obj->child_list_head);
+ spin_unlock_irqrestore(&obj->child_list_lock, flags);
+}
+
+static void sync_timeline_remove_pt(struct sync_pt *pt)
+{
+ struct sync_timeline *obj = pt->parent;
+ unsigned long flags;
+ bool needs_freeing;
+
+ spin_lock_irqsave(&obj->active_list_lock, flags);
+ if (!list_empty(&pt->active_list))
+ list_del_init(&pt->active_list);
+ spin_unlock_irqrestore(&obj->active_list_lock, flags);
+
+ spin_lock_irqsave(&obj->child_list_lock, flags);
+ list_del(&pt->child_list);
+ needs_freeing = obj->destroyed && list_empty(&obj->child_list_head);
+ spin_unlock_irqrestore(&obj->child_list_lock, flags);
+
+ if (needs_freeing)
+ kfree(obj);
+}
+
+void sync_timeline_signal(struct sync_timeline *obj)
+{
+ unsigned long flags;
+ LIST_HEAD(signaled_pts);
+ struct list_head *pos, *n;
+
+ spin_lock_irqsave(&obj->active_list_lock, flags);
+
+ list_for_each_safe(pos, n, &obj->active_list_head) {
+ struct sync_pt *pt =
+ container_of(pos, struct sync_pt, active_list);
+
+ if (_sync_pt_has_signaled(pt))
+ list_move(pos, &signaled_pts);
+ }
+
+ spin_unlock_irqrestore(&obj->active_list_lock, flags);
+
+ list_for_each_safe(pos, n, &signaled_pts) {
+ struct sync_pt *pt =
+ container_of(pos, struct sync_pt, active_list);
+
+ list_del_init(pos);
+ sync_fence_signal_pt(pt);
+ }
+}
+
+struct sync_pt *sync_pt_create(struct sync_timeline *parent, int size)
+{
+ struct sync_pt *pt;
+
+ if (size < sizeof(struct sync_pt))
+ return NULL;
+
+ pt = kzalloc(size, GFP_KERNEL);
+ if (pt == NULL)
+ return NULL;
+
+ INIT_LIST_HEAD(&pt->active_list);
+ sync_timeline_add_pt(parent, pt);
+
+ return pt;
+}
+
+void sync_pt_free(struct sync_pt *pt)
+{
+ if (pt->parent->ops->free_pt)
+ pt->parent->ops->free_pt(pt);
+
+ sync_timeline_remove_pt(pt);
+
+ kfree(pt);
+}
+
+/* call with pt->parent->active_list_lock held */
+static int _sync_pt_has_signaled(struct sync_pt *pt)
+{
+ if (!pt->status)
+ pt->status = pt->parent->ops->has_signaled(pt);
+
+ if (!pt->status && pt->parent->destroyed)
+ pt->status = -ENOENT;
+
+ return pt->status;
+}
+
+static struct sync_pt *sync_pt_dup(struct sync_pt *pt)
+{
+ return pt->parent->ops->dup(pt);
+}
+
+/* Adds a sync pt to the active queue. Called when added to a fence */
+static void sync_pt_activate(struct sync_pt *pt)
+{
+ struct sync_timeline *obj = pt->parent;
+ unsigned long flags;
+ int err;
+
+ spin_lock_irqsave(&obj->active_list_lock, flags);
+
+ err = _sync_pt_has_signaled(pt);
+ if (err != 0)
+ goto out;
+
+ list_add_tail(&pt->active_list, &obj->active_list_head);
+
+out:
+ spin_unlock_irqrestore(&obj->active_list_lock, flags);
+}
+
+static int sync_fence_release(struct inode *inode, struct file *file);
+static long sync_fence_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg);
+
+
+static const struct file_operations sync_fence_fops = {
+ .release = sync_fence_release,
+ .unlocked_ioctl = sync_fence_ioctl,
+};
+
+static struct sync_fence *sync_fence_alloc(const char *name)
+{
+ struct sync_fence *fence;
+
+ fence = kzalloc(sizeof(struct sync_fence), GFP_KERNEL);
+ if (fence == NULL)
+ return NULL;
+
+ fence->file = anon_inode_getfile("sync_fence", &sync_fence_fops,
+ fence, 0);
+ if (fence->file == NULL)
+ goto err;
+
+ strlcpy(fence->name, name, sizeof(fence->name));
+
+ INIT_LIST_HEAD(&fence->pt_list_head);
+ INIT_LIST_HEAD(&fence->waiter_list_head);
+ spin_lock_init(&fence->waiter_list_lock);
+
+ init_waitqueue_head(&fence->wq);
+ return fence;
+
+err:
+ kfree(fence);
+ return NULL;
+}
+
+/* TODO: implement a create which takes more that one sync_pt */
+struct sync_fence *sync_fence_create(const char *name, struct sync_pt *pt)
+{
+ struct sync_fence *fence;
+
+ if (pt->fence)
+ return NULL;
+
+ fence = sync_fence_alloc(name);
+ if (fence == NULL)
+ return NULL;
+
+ pt->fence = fence;
+ list_add(&pt->pt_list, &fence->pt_list_head);
+ sync_pt_activate(pt);
+
+ return fence;
+}
+
+static int sync_fence_copy_pts(struct sync_fence *dst, struct sync_fence *src)
+{
+ struct list_head *pos;
+
+ list_for_each(pos, &src->pt_list_head) {
+ struct sync_pt *orig_pt =
+ container_of(pos, struct sync_pt, pt_list);
+ struct sync_pt *new_pt = sync_pt_dup(orig_pt);
+
+ if (new_pt == NULL)
+ return -ENOMEM;
+
+ new_pt->fence = dst;
+ list_add(&new_pt->pt_list, &dst->pt_list_head);
+ sync_pt_activate(new_pt);
+ }
+
+ return 0;
+}
+
+static void sync_fence_free_pts(struct sync_fence *fence)
+{
+ struct list_head *pos, *n;
+
+ list_for_each_safe(pos, n, &fence->pt_list_head) {
+ struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
+ sync_pt_free(pt);
+ }
+}
+
+struct sync_fence *sync_fence_fdget(int fd)
+{
+ struct file *file = fget(fd);
+
+ if (file == NULL)
+ return NULL;
+
+ if (file->f_op != &sync_fence_fops)
+ goto err;
+
+ return file->private_data;
+
+err:
+ fput(file);
+ return NULL;
+}
+
+void sync_fence_put(struct sync_fence *fence)
+{
+ fput(fence->file);
+}
+
+void sync_fence_install(struct sync_fence *fence, int fd)
+{
+ fd_install(fd, fence->file);
+}
+
+static int sync_fence_get_status(struct sync_fence *fence)
+{
+ struct list_head *pos;
+ int status = 1;
+
+ list_for_each(pos, &fence->pt_list_head) {
+ struct sync_pt *pt = container_of(pos, struct sync_pt, pt_list);
+ int pt_status = pt->status;
+
+ if (pt_status < 0) {
+ status = pt_status;
+ break;
+ } else if (status == 1) {
+ status = pt_status;
+ }
+ }
+
+ return status;
+}
+
+struct sync_fence *sync_fence_merge(const char *name,
+ struct sync_fence *a, struct sync_fence *b)
+{
+ struct sync_fence *fence;
+ int err;
+
+ fence = sync_fence_alloc(name);
+ if (fence == NULL)
+ return NULL;
+
+ err = sync_fence_copy_pts(fence, a);
+ if (err < 0)
+ goto err;
+
+ err = sync_fence_copy_pts(fence, b);
+ if (err < 0)
+ goto err;
+
+ fence->status = sync_fence_get_status(fence);
+
+ return fence;
+err:
+ sync_fence_free_pts(fence);
+ kfree(fence);
+ return NULL;
+}
+
+static void sync_fence_signal_pt(struct sync_pt *pt)
+{
+ LIST_HEAD(signaled_waiters);
+ struct sync_fence *fence = pt->fence;
+ struct list_head *pos;
+ struct list_head *n;
+ unsigned long flags;
+ int status;
+
+ status = sync_fence_get_status(fence);
+
+ spin_lock_irqsave(&fence->waiter_list_lock, flags);
+ /*
+ * this should protect against two threads racing on the signaled
+ * false -> true transition
+ */
+ if (status && !fence->status) {
+ list_for_each_safe(pos, n, &fence->waiter_list_head)
+ list_move(pos, &signaled_waiters);
+
+ fence->status = status;
+ } else {
+ status = 0;
+ }
+ spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
+
+ if (status) {
+ list_for_each_safe(pos, n, &signaled_waiters) {
+ struct sync_fence_waiter *waiter =
+ container_of(pos, struct sync_fence_waiter,
+ waiter_list);
+
+ waiter->callback(fence, waiter->callback_data);
+ list_del(pos);
+ kfree(waiter);
+ }
+ wake_up(&fence->wq);
+ }
+}
+
+int sync_fence_wait_async(struct sync_fence *fence,
+ void (*callback)(struct sync_fence *, void *data),
+ void *callback_data)
+{
+ struct sync_fence_waiter *waiter;
+ unsigned long flags;
+ int err = 0;
+
+ waiter = kzalloc(sizeof(struct sync_fence_waiter), GFP_KERNEL);
+ if (waiter == NULL)
+ return -ENOMEM;
+
+ waiter->callback = callback;
+ waiter->callback_data = callback_data;
+
+ spin_lock_irqsave(&fence->waiter_list_lock, flags);
+
+ if (fence->status) {
+ kfree(waiter);
+ err = fence->status;
+ goto out;
+ }
+
+ list_add_tail(&waiter->waiter_list, &fence->waiter_list_head);
+out:
+ spin_unlock_irqrestore(&fence->waiter_list_lock, flags);
+
+ return err;
+}
+
+int sync_fence_wait(struct sync_fence *fence, long timeout)
+{
+ int err;
+
+ if (timeout) {
+ timeout = msecs_to_jiffies(timeout);
+ err = wait_event_interruptible_timeout(fence->wq,
+ fence->status != 0,
+ timeout);
+ } else {
+ err = wait_event_interruptible(fence->wq, fence->status != 0);
+ }
+
+ if (err < 0)
+ return err;
+
+ if (fence->status < 0)
+ return fence->status;
+
+ if (fence->status == 0)
+ return -ETIME;
+
+ return 0;
+}
+
+static int sync_fence_release(struct inode *inode, struct file *file)
+{
+ struct sync_fence *fence = file->private_data;
+
+ sync_fence_free_pts(fence);
+ kfree(fence);
+
+ return 0;
+}
+
+static long sync_fence_ioctl_wait(struct sync_fence *fence, unsigned long arg)
+{
+ __s32 value;
+
+ if (copy_from_user(&value, (void __user *)arg, sizeof(value)))
+ return -EFAULT;
+
+ return sync_fence_wait(fence, value);
+}
+
+static long sync_fence_ioctl_merge(struct sync_fence *fence, unsigned long arg)
+{
+ int fd = get_unused_fd();
+ int err;
+ struct sync_fence *fence2, *fence3;
+ struct sync_merge_data data;
+
+ if (copy_from_user(&data, (void __user *)arg, sizeof(data)))
+ return -EFAULT;
+
+ fence2 = sync_fence_fdget(data.fd2);
+ if (fence2 == NULL) {
+ err = -ENOENT;
+ goto err_put_fd;
+ }
+
+ data.name[sizeof(data.name) - 1] = '\0';
+ fence3 = sync_fence_merge(data.name, fence, fence2);
+ if (fence3 == NULL) {
+ err = -ENOMEM;
+ goto err_put_fence2;
+ }
+
+ data.fence = fd;
+ if (copy_to_user((void __user *)arg, &data, sizeof(data))) {
+ err = -EFAULT;
+ goto err_put_fence3;
+ }
+
+ sync_fence_install(fence3, fd);
+ sync_fence_put(fence2);
+ return 0;
+
+err_put_fence3:
+ sync_fence_put(fence3);
+
+err_put_fence2:
+ sync_fence_put(fence2);
+
+err_put_fd:
+ put_unused_fd(fd);
+ return err;
+}
+
+
+static long sync_fence_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sync_fence *fence = file->private_data;
+ switch (cmd) {
+ case SYNC_IOC_WAIT:
+ return sync_fence_ioctl_wait(fence, arg);
+
+ case SYNC_IOC_MERGE:
+ return sync_fence_ioctl_merge(fence, arg);
+ default:
+ return -ENOTTY;
+ }
+}
+