arch/s390/mm/page-states.c
Source file repositories/reference/linux-study-clean/arch/s390/mm/page-states.c
File Facts
- System
- Linux kernel
- Corpus path
arch/s390/mm/page-states.c- Extension
.c- Size
- 704 bytes
- Lines
- 34
- Domain
- Architecture Layer
- Bucket
- arch/s390
- 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/mm.hasm/page-states.hasm/sections.hasm/page.h
Detected Declarations
function arch_free_pagefunction arch_alloc_pageexport cmma_flag
Annotated Snippet
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2008
*
* Guest page hinting for unused pages.
*
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <linux/mm.h>
#include <asm/page-states.h>
#include <asm/sections.h>
#include <asm/page.h>
int __bootdata_preserved(cmma_flag);
EXPORT_SYMBOL(cmma_flag);
void arch_free_page(struct page *page, int order)
{
if (!cmma_flag)
return;
__set_page_unused(page_to_virt(page), 1UL << order);
}
void arch_alloc_page(struct page *page, int order)
{
if (!cmma_flag)
return;
if (cmma_flag < 2)
__set_page_stable_dat(page_to_virt(page), 1UL << order);
else
__set_page_stable_nodat(page_to_virt(page), 1UL << order);
}
Annotation
- Immediate include surface: `linux/mm.h`, `asm/page-states.h`, `asm/sections.h`, `asm/page.h`.
- Detected declarations: `function arch_free_page`, `function arch_alloc_page`, `export cmma_flag`.
- Atlas domain: Architecture Layer / arch/s390.
- 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.