arch/um/drivers/virt-pci.c

File Facts

System

Linux kernel

Corpus path

arch/um/drivers/virt-pci.c

Extension

.c

Size

13849 bytes

Lines

619

Domain

Architecture Layer

Bucket

arch/um

Inferred role

Architecture Layer: exported/initcall integration point

Status

integration 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.
• Exports symbols or registers init work; inspect boot/module ordering and who consumes the exported contract.
• Uses kernel synchronization; read lock ordering, sleepability, and interrupt context assumptions before translating.
• Touches IRQ or DMA behavior; this matters for the representative real-device path.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• linux/module.h
• linux/pci.h
• linux/logic_iomem.h
• linux/of_platform.h
• linux/irqchip/irq-msi-lib.h
• linux/irqdomain.h
• linux/msi.h
• linux/unaligned.h
• irq_kern.h
• virt-pci.h

Detected Declarations

• struct um_pci_device_reg
• struct um_pci_map_iomem_data
• function um_pci_cfgspace_read
• function um_pci_cfgspace_write
• function um_pci_bar_read
• function um_pci_bar_write
• function um_pci_bar_copy_from
• function um_pci_bar_copy_to
• function um_pci_bar_set
• function um_pci_rescan
• function for_each_node_by_type
• function um_pci_map_cfgspace
• function um_pci_map_iomem_walk
• function um_pci_map_iomem
• function um_pci_compose_msi_msg
• function um_pci_inner_domain_alloc
• function um_pci_inner_domain_free
• function um_pci_map_irq
• function um_pci_map_platform
• function um_pci_device_register
• function um_pci_device_unregister
• function um_pci_platform_device_register
• function um_pci_platform_device_unregister
• function um_pci_init
• function um_pci_exit
• module init um_pci_init

Annotated Snippet

device_initcall(um_pci_init);

static void __exit um_pci_exit(void)
{
	irq_domain_remove(um_pci_inner_domain);
	pci_free_resource_list(&bridge->windows);
	pci_free_host_bridge(bridge);
}
module_exit(um_pci_exit);

Annotation

• Immediate include surface: `linux/module.h`, `linux/pci.h`, `linux/logic_iomem.h`, `linux/of_platform.h`, `linux/irqchip/irq-msi-lib.h`, `linux/irqdomain.h`, `linux/msi.h`, `linux/unaligned.h`.
• Detected declarations: `struct um_pci_device_reg`, `struct um_pci_map_iomem_data`, `function um_pci_cfgspace_read`, `function um_pci_cfgspace_write`, `function um_pci_bar_read`, `function um_pci_bar_write`, `function um_pci_bar_copy_from`, `function um_pci_bar_copy_to`, `function um_pci_bar_set`, `function um_pci_rescan`.
• Atlas domain: Architecture Layer / arch/um.
• Implementation status: integration implementation candidate.
• Synchronization appears in or near this file; preserve lock ordering, sleepability, and interrupt-context constraints.
• IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.

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.