lib/crc/arm/crc32-core.S

File Facts

System

Linux kernel

Corpus path

lib/crc/arm/crc32-core.S

Extension

.S

Size

6910 bytes

Lines

307

Domain

Kernel Services

Bucket

lib

Inferred role

Kernel Services: lib

Status

atlas-only

Why This File Exists

Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

• Shared kernel service surface used by multiple subsystems, including helpers, cryptography, virtualization support, and async I/O infrastructure.

Dependency Surface

• linux/linkage.h
• asm/assembler.h

Detected Declarations

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

Annotated Snippet

#include <linux/linkage.h>
#include <asm/assembler.h>

	.text
	.align		6
	.arch		armv8-a
	.arch_extension	crc
	.fpu		crypto-neon-fp-armv8

.Lcrc32_constants:
	/*
	 * [x4*128+32 mod P(x) << 32)]'  << 1   = 0x154442bd4
	 * #define CONSTANT_R1  0x154442bd4LL
	 *
	 * [(x4*128-32 mod P(x) << 32)]' << 1   = 0x1c6e41596
	 * #define CONSTANT_R2  0x1c6e41596LL
	 */
	.quad		0x0000000154442bd4
	.quad		0x00000001c6e41596

	/*
	 * [(x128+32 mod P(x) << 32)]'   << 1   = 0x1751997d0
	 * #define CONSTANT_R3  0x1751997d0LL
	 *
	 * [(x128-32 mod P(x) << 32)]'   << 1   = 0x0ccaa009e
	 * #define CONSTANT_R4  0x0ccaa009eLL
	 */
	.quad		0x00000001751997d0
	.quad		0x00000000ccaa009e

	/*
	 * [(x64 mod P(x) << 32)]'       << 1   = 0x163cd6124
	 * #define CONSTANT_R5  0x163cd6124LL
	 */
	.quad		0x0000000163cd6124
	.quad		0x00000000FFFFFFFF

	/*
	 * #define CRCPOLY_TRUE_LE_FULL 0x1DB710641LL
	 *
	 * Barrett Reduction constant (u64`) = u` = (x**64 / P(x))`
	 *                                                      = 0x1F7011641LL
	 * #define CONSTANT_RU  0x1F7011641LL
	 */
	.quad		0x00000001DB710641
	.quad		0x00000001F7011641

.Lcrc32c_constants:
	.quad		0x00000000740eef02
	.quad		0x000000009e4addf8
	.quad		0x00000000f20c0dfe
	.quad		0x000000014cd00bd6
	.quad		0x00000000dd45aab8
	.quad		0x00000000FFFFFFFF
	.quad		0x0000000105ec76f0
	.quad		0x00000000dea713f1

	dCONSTANTl	.req	d0
	dCONSTANTh	.req	d1
	qCONSTANT	.req	q0

	BUF		.req	r0
	LEN		.req	r1
	CRC		.req	r2

	qzr		.req	q9

	/**
	 * Calculate crc32
	 * BUF - buffer

Annotation

• Immediate include surface: `linux/linkage.h`, `asm/assembler.h`.
• Atlas domain: Kernel Services / lib.
• Implementation status: atlas-only.

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.