| /* |
| * 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) |
| goto err; |
| |
| 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 unsigned int 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) ? POLLIN : 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, |
| }; |