arch/parisc/include/asm/shmparam.h

File Facts

System

Linux kernel

Corpus path

arch/parisc/include/asm/shmparam.h

Extension

.h

Size

968 bytes

Lines

24

Domain

Architecture Layer

Bucket

arch/parisc

Inferred role

Architecture Layer: implementation source

Status

source 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.

Dependency Surface

• No C-style include directives detected by the generator.

Detected Declarations

• No top-level syscall, struct, function, initcall, or export declaration detected by the generator.

Annotated Snippet

#ifndef _ASMPARISC_SHMPARAM_H
#define _ASMPARISC_SHMPARAM_H

/*
 * PA-RISC uses virtually indexed & physically tagged (VIPT) caches
 * which has strict requirements when two pages to the same physical
 * address are accessed through different mappings. Read the section
 * "Address Aliasing" in the arch docs for more detail:
 * PA-RISC 1.1 (page 3-6):
 * https://parisc.wiki.kernel.org/images-parisc/6/68/Pa11_acd.pdf
 * PA-RISC 2.0 (page F-5):
 * https://parisc.wiki.kernel.org/images-parisc/7/73/Parisc2.0.pdf
 *
 * For Linux we allow kernel and userspace to map pages on page size
 * granularity (SHMLBA) but have to ensure that, if two pages are
 * mapped to the same physical address, the virtual and physical
 * addresses modulo SHM_COLOUR are identical.
 */
#define SHMLBA	   PAGE_SIZE	/* attach addr a multiple of this */
#define SHM_COLOUR 0x00400000	/* shared mappings colouring */

#endif /* _ASMPARISC_SHMPARAM_H */

Annotation

• Atlas domain: Architecture Layer / arch/parisc.
• Implementation status: source 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.