arch/s390/include/uapi/asm/guarded_storage.h

File Facts

System

Linux kernel

Corpus path

arch/s390/include/uapi/asm/guarded_storage.h

Extension

.h

Size

1208 bytes

Lines

79

Domain

Architecture Layer

Bucket

arch/s390

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

• linux/types.h

Detected Declarations

• struct gs_cb
• struct gs_epl
• function load_gs_cb
• function store_gs_cb
• function save_gs_cb
• function restore_gs_cb

Annotated Snippet

struct gs_cb {
	__u64 reserved;
	__u64 gsd;
	__u64 gssm;
	__u64 gs_epl_a;
};

struct gs_epl {
	__u8 pad1;
	union {
		__u8 gs_eam;
		struct {
			__u8	: 6;
			__u8 e	: 1;
			__u8 b	: 1;
		};
	};
	union {
		__u8 gs_eci;
		struct {
			__u8 tx	: 1;
			__u8 cx	: 1;
			__u8	: 5;
			__u8 in	: 1;
		};
	};
	union {
		__u8 gs_eai;
		struct {
			__u8	: 1;
			__u8 t	: 1;
			__u8 as	: 2;
			__u8 ar	: 4;
		};
	};
	__u32 pad2;
	__u64 gs_eha;
	__u64 gs_eia;
	__u64 gs_eoa;
	__u64 gs_eir;
	__u64 gs_era;
};

#define GS_ENABLE	0
#define	GS_DISABLE	1
#define GS_SET_BC_CB	2
#define GS_CLEAR_BC_CB	3
#define GS_BROADCAST	4

static inline void load_gs_cb(struct gs_cb *gs_cb)
{
	asm volatile(".insn rxy,0xe3000000004d,0,%0" : : "Q" (*gs_cb));
}

static inline void store_gs_cb(struct gs_cb *gs_cb)
{
	asm volatile(".insn rxy,0xe30000000049,0,%0" : : "Q" (*gs_cb));
}

static inline void save_gs_cb(struct gs_cb *gs_cb)
{
	if (gs_cb)
		store_gs_cb(gs_cb);
}

static inline void restore_gs_cb(struct gs_cb *gs_cb)
{
	if (gs_cb)
		load_gs_cb(gs_cb);
}

#endif /* _GUARDED_STORAGE_H */

Annotation

• Immediate include surface: `linux/types.h`.
• Detected declarations: `struct gs_cb`, `struct gs_epl`, `function load_gs_cb`, `function store_gs_cb`, `function save_gs_cb`, `function restore_gs_cb`.
• Atlas domain: Architecture Layer / arch/s390.
• 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.