diff options
Diffstat (limited to 'drivers/dma-buf')
| -rw-r--r-- | drivers/dma-buf/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/dma-buf/Makefile | 1 | ||||
| -rw-r--r-- | drivers/dma-buf/sync_file.c | 395 |
3 files changed, 407 insertions, 0 deletions
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig new file mode 100644 index 000000000000..9824bc4addf8 --- /dev/null +++ b/drivers/dma-buf/Kconfig @@ -0,0 +1,11 @@ +menu "DMABUF options" + +config SYNC_FILE + bool "sync_file support for fences" + default n + select ANON_INODES + select DMA_SHARED_BUFFER + ---help--- + This option enables the fence framework synchronization to export + sync_files to userspace that can represent one or more fences. +endmenu diff --git a/drivers/dma-buf/Makefile b/drivers/dma-buf/Makefile index 57a675f90cd0..4a424eca75ed 100644 --- a/drivers/dma-buf/Makefile +++ b/drivers/dma-buf/Makefile @@ -1 +1,2 @@ obj-y := dma-buf.o fence.o reservation.o seqno-fence.o +obj-$(CONFIG_SYNC_FILE) += sync_file.o diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c new file mode 100644 index 000000000000..f08cf2d8309e --- /dev/null +++ b/drivers/dma-buf/sync_file.c @@ -0,0 +1,395 @@ +/* + * 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(int size) +{ + struct sync_file *sync_file; + + sync_file = kzalloc(size, 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; + + kref_init(&sync_file->kref); + + init_waitqueue_head(&sync_file->wq); + + return sync_file; + +err: + kfree(sync_file); + return NULL; +} + +static void fence_check_cb_func(struct fence *f, struct fence_cb *cb) +{ + struct sync_file_cb *check; + struct sync_file *sync_file; + + check = container_of(cb, struct sync_file_cb, cb); + sync_file = check->sync_file; + + if (atomic_dec_and_test(&sync_file->status)) + 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. Once this is called, the sync_file + * takes ownership of @fence. 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 fence *fence) +{ + struct sync_file *sync_file; + + sync_file = sync_file_alloc(offsetof(struct sync_file, cbs[1])); + if (!sync_file) + return NULL; + + sync_file->num_fences = 1; + atomic_set(&sync_file->status, 1); + snprintf(sync_file->name, sizeof(sync_file->name), "%s-%s%d-%d", + fence->ops->get_driver_name(fence), + fence->ops->get_timeline_name(fence), fence->context, + fence->seqno); + + sync_file->cbs[0].fence = fence; + sync_file->cbs[0].sync_file = sync_file; + if (fence_add_callback(fence, &sync_file->cbs[0].cb, + fence_check_cb_func)) + atomic_dec(&sync_file->status); + + return sync_file; +} +EXPORT_SYMBOL(sync_file_create); + +/** + * sync_file_fdget() - get a sync_file from an fd + * @fd: fd referencing a fence + * + * Ensures @fd references a valid sync_file, increments the refcount of the + * backing file. Returns the sync_file or NULL in case of error. + */ +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; +} + +static void sync_file_add_pt(struct sync_file *sync_file, int *i, + struct fence *fence) +{ + sync_file->cbs[*i].fence = fence; + sync_file->cbs[*i].sync_file = sync_file; + + if (!fence_add_callback(fence, &sync_file->cbs[*i].cb, + fence_check_cb_func)) { + 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) +{ + int num_fences = a->num_fences + b->num_fences; + struct sync_file *sync_file; + int i, i_a, i_b; + unsigned long size = offsetof(struct sync_file, cbs[num_fences]); + + sync_file = sync_file_alloc(size); + if (!sync_file) + return NULL; + + atomic_set(&sync_file->status, num_fences); + + /* + * 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 fence *pt_a = a->cbs[i_a].fence; + struct fence *pt_b = b->cbs[i_b].fence; + + if (pt_a->context < pt_b->context) { + sync_file_add_pt(sync_file, &i, pt_a); + + i_a++; + } else if (pt_a->context > pt_b->context) { + sync_file_add_pt(sync_file, &i, pt_b); + + i_b++; + } else { + if (pt_a->seqno - pt_b->seqno <= INT_MAX) + sync_file_add_pt(sync_file, &i, pt_a); + else + sync_file_add_pt(sync_file, &i, pt_b); + + i_a++; + i_b++; + } + } + + for (; i_a < a->num_fences; i_a++) + sync_file_add_pt(sync_file, &i, a->cbs[i_a].fence); + + for (; i_b < b->num_fences; i_b++) + sync_file_add_pt(sync_file, &i, b->cbs[i_b].fence); + + if (num_fences > i) + atomic_sub(num_fences - i, &sync_file->status); + sync_file->num_fences = i; + + strlcpy(sync_file->name, name, sizeof(sync_file->name)); + return sync_file; +} + +static void sync_file_free(struct kref *kref) +{ + struct sync_file *sync_file = container_of(kref, struct sync_file, + kref); + int i; + + for (i = 0; i < sync_file->num_fences; ++i) { + fence_remove_callback(sync_file->cbs[i].fence, + &sync_file->cbs[i].cb); + fence_put(sync_file->cbs[i].fence); + } + + kfree(sync_file); +} + +static int sync_file_release(struct inode *inode, struct file *file) +{ + struct sync_file *sync_file = file->private_data; + + kref_put(&sync_file->kref, sync_file_free); + return 0; +} + +static unsigned int sync_file_poll(struct file *file, poll_table *wait) +{ + struct sync_file *sync_file = file->private_data; + int status; + + poll_wait(file, &sync_file->wq, wait); + + status = atomic_read(&sync_file->status); + + if (!status) + return POLLIN; + if (status < 0) + return POLLERR; + return 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 void sync_fill_fence_info(struct 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)); + if (fence_is_signaled(fence)) + info->status = fence->status >= 0 ? 1 : fence->status; + else + info->status = 0; + info->timestamp_ns = ktime_to_ns(fence->timestamp); +} + +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; + __u32 size; + int ret, i; + + if (copy_from_user(&info, (void __user *)arg, sizeof(info))) + return -EFAULT; + + if (info.flags || info.pad) + return -EINVAL; + + /* + * 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) + goto no_fences; + + if (info.num_fences < sync_file->num_fences) + return -EINVAL; + + size = sync_file->num_fences * sizeof(*fence_info); + fence_info = kzalloc(size, GFP_KERNEL); + if (!fence_info) + return -ENOMEM; + + for (i = 0; i < sync_file->num_fences; ++i) + sync_fill_fence_info(sync_file->cbs[i].fence, &fence_info[i]); + + if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info, + size)) { + ret = -EFAULT; + goto out; + } + +no_fences: + strlcpy(info.name, sync_file->name, sizeof(info.name)); + info.status = atomic_read(&sync_file->status); + if (info.status >= 0) + info.status = !info.status; + + info.num_fences = sync_file->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, +}; + |
