lib/raid/xor/x86/xor-mmx.c

Source file repositories/reference/linux-study-clean/lib/raid/xor/x86/xor-mmx.c

File Facts

System
Linux kernel
Corpus path
lib/raid/xor/x86/xor-mmx.c
Extension
.c
Size
13851 bytes
Lines
516
Domain
Kernel Services
Bucket
lib
Inferred role
Kernel Services: implementation source
Status
source implementation candidate

Why This File Exists

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

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Optimized XOR parity functions for MMX.
 *
 * Copyright (C) 1998 Ingo Molnar.
 */
#include <asm/fpu/api.h>
#include "xor_impl.h"
#include "xor_arch.h"

#define LD(x, y)	"       movq   8*("#x")(%1), %%mm"#y"   ;\n"
#define ST(x, y)	"       movq %%mm"#y",   8*("#x")(%1)   ;\n"
#define XO1(x, y)	"       pxor   8*("#x")(%2), %%mm"#y"   ;\n"
#define XO2(x, y)	"       pxor   8*("#x")(%3), %%mm"#y"   ;\n"
#define XO3(x, y)	"       pxor   8*("#x")(%4), %%mm"#y"   ;\n"
#define XO4(x, y)	"       pxor   8*("#x")(%5), %%mm"#y"   ;\n"

static void
xor_pII_mmx_2(unsigned long bytes, unsigned long * __restrict p1,
	      const unsigned long * __restrict p2)
{
	unsigned long lines = bytes >> 7;

	asm volatile(
#undef BLOCK
#define BLOCK(i)				\
	LD(i, 0)				\
		LD(i + 1, 1)			\
			LD(i + 2, 2)		\
				LD(i + 3, 3)	\
	XO1(i, 0)				\
	ST(i, 0)				\
		XO1(i+1, 1)			\
		ST(i+1, 1)			\
			XO1(i + 2, 2)		\
			ST(i + 2, 2)		\
				XO1(i + 3, 3)	\
				ST(i + 3, 3)

	" .align 32			;\n"
	" 1:                            ;\n"

	BLOCK(0)
	BLOCK(4)
	BLOCK(8)
	BLOCK(12)

	"       addl $128, %1         ;\n"
	"       addl $128, %2         ;\n"
	"       decl %0               ;\n"
	"       jnz 1b                ;\n"
	: "+r" (lines),
	  "+r" (p1), "+r" (p2)
	:
	: "memory");
}

static void
xor_pII_mmx_3(unsigned long bytes, unsigned long * __restrict p1,
	      const unsigned long * __restrict p2,
	      const unsigned long * __restrict p3)
{
	unsigned long lines = bytes >> 7;

	asm volatile(
#undef BLOCK
#define BLOCK(i)				\
	LD(i, 0)				\
		LD(i + 1, 1)			\
			LD(i + 2, 2)		\
				LD(i + 3, 3)	\
	XO1(i, 0)				\
		XO1(i + 1, 1)			\
			XO1(i + 2, 2)		\
				XO1(i + 3, 3)	\
	XO2(i, 0)				\
	ST(i, 0)				\
		XO2(i + 1, 1)			\
		ST(i + 1, 1)			\
			XO2(i + 2, 2)		\
			ST(i + 2, 2)		\
				XO2(i + 3, 3)	\
				ST(i + 3, 3)

	" .align 32			;\n"
	" 1:                            ;\n"

	BLOCK(0)
	BLOCK(4)
	BLOCK(8)

Annotation

Implementation Notes