arch/sh/boards/mach-landisk/gio.c

File Facts

System

Linux kernel

Corpus path

arch/sh/boards/mach-landisk/gio.c

Extension

.c

Size

3251 bytes

Lines

165

Domain

Architecture Layer

Bucket

arch/sh

Inferred role

Architecture Layer: operation-table or driver-model contract

Status

pattern implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

• CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.
• 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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/module.h
• linux/init.h
• linux/kdev_t.h
• linux/cdev.h
• linux/fs.h
• asm/io.h
• linux/uaccess.h
• mach-landisk/mach/gio.h
• mach-landisk/mach/iodata_landisk.h

Detected Declarations

• function gio_open
• function gio_close
• function gio_ioctl
• function gio_init
• function gio_exit
• module init gio_init

Annotated Snippet

static const struct file_operations gio_fops = {
	.owner = THIS_MODULE,
	.open = gio_open,	/* open */
	.release = gio_close,	/* release */
	.unlocked_ioctl = gio_ioctl,
	.llseek = noop_llseek,
};

static int __init gio_init(void)
{
	int error;

	printk(KERN_INFO "gio: driver initialized\n");

	openCnt = 0;

	if ((error = alloc_chrdev_region(&dev, 0, DEVCOUNT, "gio")) < 0) {
		printk(KERN_ERR
		       "gio: Couldn't alloc_chrdev_region, error=%d\n",
		       error);
		return 1;
	}

	cdev_p = cdev_alloc();
	cdev_p->ops = &gio_fops;
	error = cdev_add(cdev_p, dev, DEVCOUNT);
	if (error) {
		printk(KERN_ERR
		       "gio: Couldn't cdev_add, error=%d\n", error);
		return 1;
	}

	return 0;
}

static void __exit gio_exit(void)
{
	cdev_del(cdev_p);
	unregister_chrdev_region(dev, DEVCOUNT);
}

module_init(gio_init);
module_exit(gio_exit);

MODULE_LICENSE("GPL");

Annotation

• Immediate include surface: `linux/module.h`, `linux/init.h`, `linux/kdev_t.h`, `linux/cdev.h`, `linux/fs.h`, `asm/io.h`, `linux/uaccess.h`, `mach-landisk/mach/gio.h`.
• Detected declarations: `function gio_open`, `function gio_close`, `function gio_ioctl`, `function gio_init`, `function gio_exit`, `module init gio_init`.
• Atlas domain: Architecture Layer / arch/sh.
• Implementation status: pattern implementation candidate.
• This snippet crosses the user/kernel memory boundary; validate fault handling and access checks before translating the pattern.

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.