arch/xtensa/include/uapi/asm/shmbuf.h

File Facts

System

Linux kernel

Corpus path

arch/xtensa/include/uapi/asm/shmbuf.h

Extension

.h

Size

1605 bytes

Lines

55

Domain

Architecture Layer

Bucket

arch/xtensa

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.
• Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.

Dependency Surface

• asm/ipcbuf.h
• asm/posix_types.h

Detected Declarations

• struct shmid64_ds
• struct shminfo64

Annotated Snippet

struct shmid64_ds {
	struct ipc64_perm	shm_perm;	/* operation perms */
	__kernel_size_t		shm_segsz;	/* size of segment (bytes) */
	unsigned long		shm_atime;	/* last attach time */
	unsigned long		shm_atime_high;
	unsigned long		shm_dtime;	/* last detach time */
	unsigned long		shm_dtime_high;
	unsigned long		shm_ctime;	/* last change time */
	unsigned long		shm_ctime_high;
	__kernel_pid_t		shm_cpid;	/* pid of creator */
	__kernel_pid_t		shm_lpid;	/* pid of last operator */
	unsigned long		shm_nattch;	/* no. of current attaches */
	unsigned long		__unused4;
	unsigned long		__unused5;
};

struct shminfo64 {
	unsigned long	shmmax;
	unsigned long	shmmin;
	unsigned long	shmmni;
	unsigned long	shmseg;
	unsigned long	shmall;
	unsigned long	__unused1;
	unsigned long	__unused2;
	unsigned long	__unused3;
	unsigned long	__unused4;
};

#endif	/* _XTENSA_SHMBUF_H */

Annotation

• Immediate include surface: `asm/ipcbuf.h`, `asm/posix_types.h`.
• Detected declarations: `struct shmid64_ds`, `struct shminfo64`.
• Atlas domain: Architecture Layer / arch/xtensa.
• 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.