drivers/pci/vgaarb.c

File Facts

System

Linux kernel

Corpus path

drivers/pci/vgaarb.c

Extension

.c

Size

42050 bytes

Lines

1546

Domain

Representative Device Path

Bucket

PCIe NVMe Storage Path

Inferred role

Representative Device Path: operation-table or driver-model contract

Status

pattern implementation candidate

Why This File Exists

Part of the selected hardware vertical slice: PCI discovery, driver binding, NVMe queues, block requests, DMA, interrupts, and completion.

• Part of the selected hardware vertical slice: PCI discovery, driver binding, NVMe queues, block requests, DMA, interrupts, and completion.
• 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/module.h
• linux/kernel.h
• linux/pci.h
• linux/errno.h
• linux/init.h
• linux/list.h
• linux/sched/signal.h
• linux/wait.h
• linux/spinlock.h
• linux/poll.h
• linux/miscdevice.h
• linux/slab.h
• linux/sysfb.h
• linux/vt.h
• linux/console.h
• linux/acpi.h
• linux/uaccess.h
• linux/vgaarb.h

Detected Declarations

• struct vga_device
• struct vga_arb_user_card
• struct vga_arb_private
• function vga_str_to_iostate
• function vga_set_default_device
• function vga_remove_vgacon
• function vga_remove_vgacon
• function vga_remove_vgacon
• function vga_check_first_use
• function __vga_put
• function card
• function vga_get
• function vga_get
• function vga_is_firmware_default
• function vga_arb_integrated_gpu
• function vga_is_boot_device
• function vga_arbiter_check_bridge_sharing
• function list_for_each_entry
• function vga_arbiter_add_pci_device
• function vga_arbiter_del_pci_device
• function vga_update_device_decodes
• function __vga_set_legacy_decoding
• function process
• function vga_client_register
• function vga_pci_str_to_vars
• function vga_arb_read
• function vga_arb_write
• function vga_arb_fpoll
• function vga_arb_open
• function vga_arb_release
• function vga_arbiter_notify_clients
• function pci_notify
• function vga_arb_device_init
• function pci_get_subsys
• export vga_default_device
• export vga_remove_vgacon
• export vga_get
• export vga_put
• export vga_set_legacy_decoding
• export vga_client_register

Annotated Snippet

static const struct file_operations vga_arb_device_fops = {
	.read = vga_arb_read,
	.write = vga_arb_write,
	.poll = vga_arb_fpoll,
	.open = vga_arb_open,
	.release = vga_arb_release,
	.llseek = noop_llseek,
};

static struct miscdevice vga_arb_device = {
	MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops
};

static int __init vga_arb_device_init(void)
{
	int rc;
	struct pci_dev *pdev;

	rc = misc_register(&vga_arb_device);
	if (rc < 0)
		pr_err("error %d registering device\n", rc);

	bus_register_notifier(&pci_bus_type, &pci_notifier);

	/* Add all VGA class PCI devices by default */
	pdev = NULL;
	while ((pdev =
		pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
			       PCI_ANY_ID, pdev)) != NULL) {
		if (pci_is_vga(pdev))
			vga_arbiter_add_pci_device(pdev);
	}

	pr_info("loaded\n");
	return rc;
}
subsys_initcall_sync(vga_arb_device_init);

Annotation

• Immediate include surface: `linux/module.h`, `linux/kernel.h`, `linux/pci.h`, `linux/errno.h`, `linux/init.h`, `linux/list.h`, `linux/sched/signal.h`, `linux/wait.h`.
• Detected declarations: `struct vga_device`, `struct vga_arb_user_card`, `struct vga_arb_private`, `function vga_str_to_iostate`, `function vga_set_default_device`, `function vga_remove_vgacon`, `function vga_remove_vgacon`, `function vga_remove_vgacon`, `function vga_check_first_use`, `function __vga_put`.
• Atlas domain: Representative Device Path / PCIe NVMe Storage Path.
• 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.