v4.19.13 snapshot.
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
new file mode 100644
index 0000000..35dd064
--- /dev/null
+++ b/drivers/dma-buf/sync_file.c
@@ -0,0 +1,492 @@
+/*
+ * drivers/dma-buf/sync_file.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/export.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/anon_inodes.h>
+#include <linux/sync_file.h>
+#include <uapi/linux/sync_file.h>
+
+static const struct file_operations sync_file_fops;
+
+static struct sync_file *sync_file_alloc(void)
+{
+ struct sync_file *sync_file;
+
+ sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
+ if (!sync_file)
+ return NULL;
+
+ sync_file->file = anon_inode_getfile("sync_file", &sync_file_fops,
+ sync_file, 0);
+ if (IS_ERR(sync_file->file))
+ goto err;
+
+ init_waitqueue_head(&sync_file->wq);
+
+ INIT_LIST_HEAD(&sync_file->cb.node);
+
+ return sync_file;
+
+err:
+ kfree(sync_file);
+ return NULL;
+}
+
+static void fence_check_cb_func(struct dma_fence *f, struct dma_fence_cb *cb)
+{
+ struct sync_file *sync_file;
+
+ sync_file = container_of(cb, struct sync_file, cb);
+
+ wake_up_all(&sync_file->wq);
+}
+
+/**
+ * sync_file_create() - creates a sync file
+ * @fence: fence to add to the sync_fence
+ *
+ * Creates a sync_file containg @fence. This function acquires and additional
+ * reference of @fence for the newly-created &sync_file, if it succeeds. The
+ * sync_file can be released with fput(sync_file->file). Returns the
+ * sync_file or NULL in case of error.
+ */
+struct sync_file *sync_file_create(struct dma_fence *fence)
+{
+ struct sync_file *sync_file;
+
+ sync_file = sync_file_alloc();
+ if (!sync_file)
+ return NULL;
+
+ sync_file->fence = dma_fence_get(fence);
+
+ return sync_file;
+}
+EXPORT_SYMBOL(sync_file_create);
+
+static struct sync_file *sync_file_fdget(int fd)
+{
+ struct file *file = fget(fd);
+
+ if (!file)
+ return NULL;
+
+ if (file->f_op != &sync_file_fops)
+ goto err;
+
+ return file->private_data;
+
+err:
+ fput(file);
+ return NULL;
+}
+
+/**
+ * sync_file_get_fence - get the fence related to the sync_file fd
+ * @fd: sync_file fd to get the fence from
+ *
+ * Ensures @fd references a valid sync_file and returns a fence that
+ * represents all fence in the sync_file. On error NULL is returned.
+ */
+struct dma_fence *sync_file_get_fence(int fd)
+{
+ struct sync_file *sync_file;
+ struct dma_fence *fence;
+
+ sync_file = sync_file_fdget(fd);
+ if (!sync_file)
+ return NULL;
+
+ fence = dma_fence_get(sync_file->fence);
+ fput(sync_file->file);
+
+ return fence;
+}
+EXPORT_SYMBOL(sync_file_get_fence);
+
+/**
+ * sync_file_get_name - get the name of the sync_file
+ * @sync_file: sync_file to get the fence from
+ * @buf: destination buffer to copy sync_file name into
+ * @len: available size of destination buffer.
+ *
+ * Each sync_file may have a name assigned either by the user (when merging
+ * sync_files together) or created from the fence it contains. In the latter
+ * case construction of the name is deferred until use, and so requires
+ * sync_file_get_name().
+ *
+ * Returns: a string representing the name.
+ */
+char *sync_file_get_name(struct sync_file *sync_file, char *buf, int len)
+{
+ if (sync_file->user_name[0]) {
+ strlcpy(buf, sync_file->user_name, len);
+ } else {
+ struct dma_fence *fence = sync_file->fence;
+
+ snprintf(buf, len, "%s-%s%llu-%d",
+ fence->ops->get_driver_name(fence),
+ fence->ops->get_timeline_name(fence),
+ fence->context,
+ fence->seqno);
+ }
+
+ return buf;
+}
+
+static int sync_file_set_fence(struct sync_file *sync_file,
+ struct dma_fence **fences, int num_fences)
+{
+ struct dma_fence_array *array;
+
+ /*
+ * The reference for the fences in the new sync_file and held
+ * in add_fence() during the merge procedure, so for num_fences == 1
+ * we already own a new reference to the fence. For num_fence > 1
+ * we own the reference of the dma_fence_array creation.
+ */
+ if (num_fences == 1) {
+ sync_file->fence = fences[0];
+ kfree(fences);
+ } else {
+ array = dma_fence_array_create(num_fences, fences,
+ dma_fence_context_alloc(1),
+ 1, false);
+ if (!array)
+ return -ENOMEM;
+
+ sync_file->fence = &array->base;
+ }
+
+ return 0;
+}
+
+static struct dma_fence **get_fences(struct sync_file *sync_file,
+ int *num_fences)
+{
+ if (dma_fence_is_array(sync_file->fence)) {
+ struct dma_fence_array *array = to_dma_fence_array(sync_file->fence);
+
+ *num_fences = array->num_fences;
+ return array->fences;
+ }
+
+ *num_fences = 1;
+ return &sync_file->fence;
+}
+
+static void add_fence(struct dma_fence **fences,
+ int *i, struct dma_fence *fence)
+{
+ fences[*i] = fence;
+
+ if (!dma_fence_is_signaled(fence)) {
+ dma_fence_get(fence);
+ (*i)++;
+ }
+}
+
+/**
+ * sync_file_merge() - merge two sync_files
+ * @name: name of new fence
+ * @a: sync_file a
+ * @b: sync_file b
+ *
+ * Creates a new sync_file which contains copies of all the fences in both
+ * @a and @b. @a and @b remain valid, independent sync_file. Returns the
+ * new merged sync_file or NULL in case of error.
+ */
+static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
+ struct sync_file *b)
+{
+ struct sync_file *sync_file;
+ struct dma_fence **fences, **nfences, **a_fences, **b_fences;
+ int i, i_a, i_b, num_fences, a_num_fences, b_num_fences;
+
+ sync_file = sync_file_alloc();
+ if (!sync_file)
+ return NULL;
+
+ a_fences = get_fences(a, &a_num_fences);
+ b_fences = get_fences(b, &b_num_fences);
+ if (a_num_fences > INT_MAX - b_num_fences)
+ return NULL;
+
+ num_fences = a_num_fences + b_num_fences;
+
+ fences = kcalloc(num_fences, sizeof(*fences), GFP_KERNEL);
+ if (!fences)
+ goto err;
+
+ /*
+ * Assume sync_file a and b are both ordered and have no
+ * duplicates with the same context.
+ *
+ * If a sync_file can only be created with sync_file_merge
+ * and sync_file_create, this is a reasonable assumption.
+ */
+ for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {
+ struct dma_fence *pt_a = a_fences[i_a];
+ struct dma_fence *pt_b = b_fences[i_b];
+
+ if (pt_a->context < pt_b->context) {
+ add_fence(fences, &i, pt_a);
+
+ i_a++;
+ } else if (pt_a->context > pt_b->context) {
+ add_fence(fences, &i, pt_b);
+
+ i_b++;
+ } else {
+ if (pt_a->seqno - pt_b->seqno <= INT_MAX)
+ add_fence(fences, &i, pt_a);
+ else
+ add_fence(fences, &i, pt_b);
+
+ i_a++;
+ i_b++;
+ }
+ }
+
+ for (; i_a < a_num_fences; i_a++)
+ add_fence(fences, &i, a_fences[i_a]);
+
+ for (; i_b < b_num_fences; i_b++)
+ add_fence(fences, &i, b_fences[i_b]);
+
+ if (i == 0)
+ fences[i++] = dma_fence_get(a_fences[0]);
+
+ if (num_fences > i) {
+ nfences = krealloc(fences, i * sizeof(*fences),
+ GFP_KERNEL);
+ if (!nfences)
+ goto err;
+
+ fences = nfences;
+ }
+
+ if (sync_file_set_fence(sync_file, fences, i) < 0) {
+ kfree(fences);
+ goto err;
+ }
+
+ strlcpy(sync_file->user_name, name, sizeof(sync_file->user_name));
+ return sync_file;
+
+err:
+ fput(sync_file->file);
+ return NULL;
+
+}
+
+static int sync_file_release(struct inode *inode, struct file *file)
+{
+ struct sync_file *sync_file = file->private_data;
+
+ if (test_bit(POLL_ENABLED, &sync_file->flags))
+ dma_fence_remove_callback(sync_file->fence, &sync_file->cb);
+ dma_fence_put(sync_file->fence);
+ kfree(sync_file);
+
+ return 0;
+}
+
+static __poll_t sync_file_poll(struct file *file, poll_table *wait)
+{
+ struct sync_file *sync_file = file->private_data;
+
+ poll_wait(file, &sync_file->wq, wait);
+
+ if (list_empty(&sync_file->cb.node) &&
+ !test_and_set_bit(POLL_ENABLED, &sync_file->flags)) {
+ if (dma_fence_add_callback(sync_file->fence, &sync_file->cb,
+ fence_check_cb_func) < 0)
+ wake_up_all(&sync_file->wq);
+ }
+
+ return dma_fence_is_signaled(sync_file->fence) ? EPOLLIN : 0;
+}
+
+static long sync_file_ioctl_merge(struct sync_file *sync_file,
+ unsigned long arg)
+{
+ int fd = get_unused_fd_flags(O_CLOEXEC);
+ int err;
+ struct sync_file *fence2, *fence3;
+ struct sync_merge_data data;
+
+ if (fd < 0)
+ return fd;
+
+ if (copy_from_user(&data, (void __user *)arg, sizeof(data))) {
+ err = -EFAULT;
+ goto err_put_fd;
+ }
+
+ if (data.flags || data.pad) {
+ err = -EINVAL;
+ goto err_put_fd;
+ }
+
+ fence2 = sync_file_fdget(data.fd2);
+ if (!fence2) {
+ err = -ENOENT;
+ goto err_put_fd;
+ }
+
+ data.name[sizeof(data.name) - 1] = '\0';
+ fence3 = sync_file_merge(data.name, sync_file, fence2);
+ if (!fence3) {
+ 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;
+ }
+
+ fd_install(fd, fence3->file);
+ fput(fence2->file);
+ return 0;
+
+err_put_fence3:
+ fput(fence3->file);
+
+err_put_fence2:
+ fput(fence2->file);
+
+err_put_fd:
+ put_unused_fd(fd);
+ return err;
+}
+
+static int sync_fill_fence_info(struct dma_fence *fence,
+ struct sync_fence_info *info)
+{
+ strlcpy(info->obj_name, fence->ops->get_timeline_name(fence),
+ sizeof(info->obj_name));
+ strlcpy(info->driver_name, fence->ops->get_driver_name(fence),
+ sizeof(info->driver_name));
+
+ info->status = dma_fence_get_status(fence);
+ while (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags) &&
+ !test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags))
+ cpu_relax();
+ info->timestamp_ns =
+ test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags) ?
+ ktime_to_ns(fence->timestamp) :
+ ktime_set(0, 0);
+
+ return info->status;
+}
+
+static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
+ unsigned long arg)
+{
+ struct sync_file_info info;
+ struct sync_fence_info *fence_info = NULL;
+ struct dma_fence **fences;
+ __u32 size;
+ int num_fences, ret, i;
+
+ if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
+ return -EFAULT;
+
+ if (info.flags || info.pad)
+ return -EINVAL;
+
+ fences = get_fences(sync_file, &num_fences);
+
+ /*
+ * Passing num_fences = 0 means that userspace doesn't want to
+ * retrieve any sync_fence_info. If num_fences = 0 we skip filling
+ * sync_fence_info and return the actual number of fences on
+ * info->num_fences.
+ */
+ if (!info.num_fences) {
+ info.status = dma_fence_is_signaled(sync_file->fence);
+ goto no_fences;
+ } else {
+ info.status = 1;
+ }
+
+ if (info.num_fences < num_fences)
+ return -EINVAL;
+
+ size = num_fences * sizeof(*fence_info);
+ fence_info = kzalloc(size, GFP_KERNEL);
+ if (!fence_info)
+ return -ENOMEM;
+
+ for (i = 0; i < num_fences; i++) {
+ int status = sync_fill_fence_info(fences[i], &fence_info[i]);
+ info.status = info.status <= 0 ? info.status : status;
+ }
+
+ if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
+ size)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+no_fences:
+ sync_file_get_name(sync_file, info.name, sizeof(info.name));
+ info.num_fences = num_fences;
+
+ if (copy_to_user((void __user *)arg, &info, sizeof(info)))
+ ret = -EFAULT;
+ else
+ ret = 0;
+
+out:
+ kfree(fence_info);
+
+ return ret;
+}
+
+static long sync_file_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ struct sync_file *sync_file = file->private_data;
+
+ switch (cmd) {
+ case SYNC_IOC_MERGE:
+ return sync_file_ioctl_merge(sync_file, arg);
+
+ case SYNC_IOC_FILE_INFO:
+ return sync_file_ioctl_fence_info(sync_file, arg);
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+static const struct file_operations sync_file_fops = {
+ .release = sync_file_release,
+ .poll = sync_file_poll,
+ .unlocked_ioctl = sync_file_ioctl,
+ .compat_ioctl = sync_file_ioctl,
+};