arch/s390/include/asm/ebcdic.h

File Facts

System

Linux kernel

Corpus path

arch/s390/include/asm/ebcdic.h

Extension

.h

Size

1431 bytes

Lines

48

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.

Dependency Surface

• linux/types.h

Detected Declarations

• function codepage_convert

Annotated Snippet

#ifndef _EBCDIC_H
#define _EBCDIC_H

#include <linux/types.h>

extern __u8 _ascebc_500[256];   /* ASCII -> EBCDIC 500 conversion table */
extern __u8 _ebcasc_500[256];   /* EBCDIC 500 -> ASCII conversion table */
extern __u8 _ascebc[256];   /* ASCII -> EBCDIC conversion table */
extern __u8 _ebcasc[256];   /* EBCDIC -> ASCII conversion table */
extern __u8 _ebc_tolower[256]; /* EBCDIC -> lowercase */
extern __u8 _ebc_toupper[256]; /* EBCDIC -> uppercase */

static inline void
codepage_convert(const __u8 *codepage, volatile char *addr, unsigned long nr)
{
	if (!nr--)
		return;
	asm volatile(
		"	j	2f\n"
		"0:	tr	0(1,%0),0(%2)\n"
		"1:	tr	0(256,%0),0(%2)\n"
		"	la	%0,256(%0)\n"
		"2:	aghi	%1,-256\n"
		"	jnm	1b\n"
		"	exrl	%1,0b"
		: "+&a" (addr), "+&a" (nr)
		: "a" (codepage) : "cc", "memory");
}

#define ASCEBC(addr,nr) codepage_convert(_ascebc, addr, nr)
#define EBCASC(addr,nr) codepage_convert(_ebcasc, addr, nr)
#define ASCEBC_500(addr,nr) codepage_convert(_ascebc_500, addr, nr)
#define EBCASC_500(addr,nr) codepage_convert(_ebcasc_500, addr, nr)
#define EBC_TOLOWER(addr,nr) codepage_convert(_ebc_tolower, addr, nr)
#define EBC_TOUPPER(addr,nr) codepage_convert(_ebc_toupper, addr, nr)

#endif

Annotation

• Immediate include surface: `linux/types.h`.
• Detected declarations: `function codepage_convert`.
• 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.