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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/dma-buf/sync_file.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/dma-buf/sync_file.c')
| -rw-r--r-- | drivers/dma-buf/sync_file.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c new file mode 100644 index 000000000..2166bbdf7 --- /dev/null +++ b/drivers/dma-buf/sync_file.c @@ -0,0 +1,407 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * drivers/dma-buf/sync_file.c + * + * Copyright (C) 2012 Google, Inc. + */ + +#include <linux/dma-fence-unwrap.h> +#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_obj(*sync_file); + 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]) { + strscpy(buf, sync_file->user_name, len); + } else { + struct dma_fence *fence = sync_file->fence; + const char __rcu *timeline; + const char __rcu *driver; + + rcu_read_lock(); + driver = dma_fence_driver_name(fence); + timeline = dma_fence_timeline_name(fence); + snprintf(buf, len, "%s-%s%llu-%lld", + rcu_dereference(driver), + rcu_dereference(timeline), + fence->context, + fence->seqno); + rcu_read_unlock(); + } + + return buf; +} + +/** + * 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 *fence; + + sync_file = sync_file_alloc(); + if (!sync_file) + return NULL; + + fence = dma_fence_unwrap_merge(a->fence, b->fence); + if (!fence) { + fput(sync_file->file); + return NULL; + } + sync_file->fence = fence; + strscpy(sync_file->user_name, name, sizeof(sync_file->user_name)); + return sync_file; +} + +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) +{ + const char __rcu *timeline; + const char __rcu *driver; + + rcu_read_lock(); + + driver = dma_fence_driver_name(fence); + timeline = dma_fence_timeline_name(fence); + + strscpy(info->obj_name, rcu_dereference(timeline), + sizeof(info->obj_name)); + strscpy(info->driver_name, rcu_dereference(driver), + sizeof(info->driver_name)); + + info->status = dma_fence_get_status(fence); + info->timestamp_ns = + dma_fence_is_signaled(fence) ? + ktime_to_ns(dma_fence_timestamp(fence)) : + ktime_set(0, 0); + + rcu_read_unlock(); + + return info->status; +} + +static long sync_file_ioctl_fence_info(struct sync_file *sync_file, + unsigned long arg) +{ + struct sync_fence_info *fence_info = NULL; + struct dma_fence_unwrap iter; + struct sync_file_info info; + unsigned int num_fences; + struct dma_fence *fence; + int ret; + __u32 size; + + if (copy_from_user(&info, (void __user *)arg, sizeof(info))) + return -EFAULT; + + if (info.flags || info.pad) + return -EINVAL; + + num_fences = 0; + dma_fence_unwrap_for_each(fence, &iter, sync_file->fence) + ++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_get_status(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; + + num_fences = 0; + dma_fence_unwrap_for_each(fence, &iter, sync_file->fence) { + int status; + + status = sync_fill_fence_info(fence, &fence_info[num_fences++]); + 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 int sync_file_ioctl_set_deadline(struct sync_file *sync_file, + unsigned long arg) +{ + struct sync_set_deadline ts; + + if (copy_from_user(&ts, (void __user *)arg, sizeof(ts))) + return -EFAULT; + + if (ts.pad) + return -EINVAL; + + dma_fence_set_deadline(sync_file->fence, ns_to_ktime(ts.deadline_ns)); + + return 0; +} + +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); + + case SYNC_IOC_SET_DEADLINE: + return sync_file_ioctl_set_deadline(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 = compat_ptr_ioctl, +}; |
