drivers/xen/xenbus/xenbus_dev_frontend.c

File Facts

System

Linux kernel

Corpus path

drivers/xen/xenbus/xenbus_dev_frontend.c

Extension

.c

Size

17032 bytes

Lines

725

Domain

Driver Families

Bucket

drivers/xen

Inferred role

Driver Families: operation-table or driver-model contract

Status

pattern implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

• Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.
• Defines an operation table; this is where Linux turns generic core objects into subsystem-specific behavior.
• Touches user memory; correctness depends on fault-safe copying and privilege boundary handling.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Allocates kernel memory; connect allocation flags and lifetime to context constraints.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/kernel.h
• linux/errno.h
• linux/uio.h
• linux/notifier.h
• linux/wait.h
• linux/fs.h
• linux/poll.h
• linux/mutex.h
• linux/sched.h
• linux/spinlock.h
• linux/mount.h
• linux/pagemap.h
• linux/uaccess.h
• linux/init.h
• linux/namei.h
• linux/string.h
• linux/slab.h
• linux/miscdevice.h
• linux/workqueue.h
• xen/xenbus.h
• xen/xen.h
• asm/xen/hypervisor.h
• xenbus.h

Detected Declarations

• struct xenbus_transaction_holder
• struct read_buffer
• struct xenbus_file_priv
• struct watch_adapter
• function xenbus_file_read
• function queue_reply
• function queue_cleanup
• function free_watch_adapter
• function watch_fired
• function xenbus_worker
• function list_for_each_entry_safe
• function list_for_each_entry_safe
• function list_for_each_entry_safe
• function xenbus_file_free
• function xenbus_dev_queue_reply
• function xenbus_command_reply
• function xenbus_write_transaction
• function xenbus_write_watch
• function list_for_each_entry
• function xenbus_file_write
• function xenbus_file_open
• function xenbus_file_release
• function xenbus_file_poll
• function xenbus_init
• module init xenbus_init
• export xen_xenbus_fops

Annotated Snippet

const struct file_operations xen_xenbus_fops = {
	.read = xenbus_file_read,
	.write = xenbus_file_write,
	.open = xenbus_file_open,
	.release = xenbus_file_release,
	.poll = xenbus_file_poll,
};
EXPORT_SYMBOL_GPL(xen_xenbus_fops);

static struct miscdevice xenbus_dev = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "xen/xenbus",
	.fops = &xen_xenbus_fops,
};

static int __init xenbus_init(void)
{
	int err;

	if (!xen_domain())
		return -ENODEV;

	err = misc_register(&xenbus_dev);
	if (err)
		pr_err("Could not register xenbus frontend device\n");
	return err;
}
device_initcall(xenbus_init);

Annotation

• Immediate include surface: `linux/kernel.h`, `linux/errno.h`, `linux/uio.h`, `linux/notifier.h`, `linux/wait.h`, `linux/fs.h`, `linux/poll.h`, `linux/mutex.h`.
• Detected declarations: `struct xenbus_transaction_holder`, `struct read_buffer`, `struct xenbus_file_priv`, `struct watch_adapter`, `function xenbus_file_read`, `function queue_reply`, `function queue_cleanup`, `function free_watch_adapter`, `function watch_fired`, `function xenbus_worker`.
• Atlas domain: Driver Families / drivers/xen.
• Implementation status: pattern implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.

Implementation Notes

• This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
• Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
• Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.