arch/arm/mm/iomap.c
Source file repositories/reference/linux-study-clean/arch/arm/mm/iomap.c
File Facts
- System
- Linux kernel
- Corpus path
arch/arm/mm/iomap.c- Extension
.c- Size
- 917 bytes
- Lines
- 46
- Domain
- Architecture Layer
- Bucket
- arch/arm
- 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.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
linux/module.hlinux/pci.hlinux/ioport.hlinux/io.hasm/vga.h
Detected Declarations
function ioport_unmapfunction pci_iounmapexport vga_baseexport ioport_mapexport ioport_unmapexport pcibios_min_ioexport pcibios_min_memexport pci_iounmap
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/arm/mm/iomap.c
*
* Map IO port and PCI memory spaces so that {read,write}[bwl] can
* be used to access this memory.
*/
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/io.h>
#include <asm/vga.h>
unsigned long vga_base;
EXPORT_SYMBOL(vga_base);
#ifdef __io
void __iomem *ioport_map(unsigned long port, unsigned int nr)
{
return __io(port);
}
EXPORT_SYMBOL(ioport_map);
void ioport_unmap(void __iomem *addr)
{
}
EXPORT_SYMBOL(ioport_unmap);
#endif
#ifdef CONFIG_PCI
unsigned long pcibios_min_io = 0x1000;
EXPORT_SYMBOL(pcibios_min_io);
unsigned long pcibios_min_mem = 0x01000000;
EXPORT_SYMBOL(pcibios_min_mem);
void pci_iounmap(struct pci_dev *dev, void __iomem *addr)
{
if ((unsigned long)addr >= VMALLOC_START &&
(unsigned long)addr < VMALLOC_END)
iounmap(addr);
}
EXPORT_SYMBOL(pci_iounmap);
#endif
Annotation
- Immediate include surface: `linux/module.h`, `linux/pci.h`, `linux/ioport.h`, `linux/io.h`, `asm/vga.h`.
- Detected declarations: `function ioport_unmap`, `function pci_iounmap`, `export vga_base`, `export ioport_map`, `export ioport_unmap`, `export pcibios_min_io`, `export pcibios_min_mem`, `export pci_iounmap`.
- Atlas domain: Architecture Layer / arch/arm.
- Implementation status: integration implementation candidate.
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.