arch/arm/lib/io-readsw-armv4.S

Source file repositories/reference/linux-study-clean/arch/arm/lib/io-readsw-armv4.S

File Facts

System
Linux kernel
Corpus path
arch/arm/lib/io-readsw-armv4.S
Extension
.S
Size
2232 bytes
Lines
129
Domain
Architecture Layer
Bucket
arch/arm
Inferred role
Architecture Layer: arch/arm
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

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

		.macro	pack, rd, hw1, hw2
#ifndef __ARMEB__
		orr	\rd, \hw1, \hw2, lsl #16
#else
		orr	\rd, \hw2, \hw1, lsl #16
#endif
		.endm

.Linsw_align:	movs	ip, r1, lsl #31
		bne	.Linsw_noalign
		ldrh	ip, [r0]
		sub	r2, r2, #1
		strh	ip, [r1], #2

ENTRY(__raw_readsw)
		teq	r2, #0
		reteq	lr
		tst	r1, #3
		bne	.Linsw_align

		stmfd	sp!, {r4, r5, lr}

		subs	r2, r2, #8
		bmi	.Lno_insw_8

.Linsw_8_lp:	ldrh	r3, [r0]
		ldrh	r4, [r0]
		pack	r3, r3, r4

		ldrh	r4, [r0]
		ldrh	r5, [r0]
		pack	r4, r4, r5

		ldrh	r5, [r0]
		ldrh	ip, [r0]
		pack	r5, r5, ip

		ldrh	ip, [r0]
		ldrh	lr, [r0]
		pack	ip, ip, lr

		subs	r2, r2, #8
		stmia	r1!, {r3 - r5, ip}
		bpl	.Linsw_8_lp

.Lno_insw_8:	tst	r2, #4
		beq	.Lno_insw_4

		ldrh	r3, [r0]
		ldrh	r4, [r0]
		pack	r3, r3, r4

		ldrh	r4, [r0]
		ldrh	ip, [r0]
		pack	r4, r4, ip

		stmia	r1!, {r3, r4}

.Lno_insw_4:	movs	r2, r2, lsl #31
		bcc	.Lno_insw_2

		ldrh	r3, [r0]
		ldrh	ip, [r0]
		pack	r3, r3, ip
		str	r3, [r1], #4

.Lno_insw_2:	ldrhne	r3, [r0]

Annotation

Implementation Notes