arch/nios2/include/asm/entry.h

Source file repositories/reference/linux-study-clean/arch/nios2/include/asm/entry.h

File Facts

System
Linux kernel
Corpus path
arch/nios2/include/asm/entry.h
Extension
.h
Size
2661 bytes
Lines
122
Domain
Architecture Layer
Bucket
arch/nios2
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.

Dependency Surface

Detected Declarations

Annotated Snippet

#ifndef _ASM_NIOS2_ENTRY_H
#define _ASM_NIOS2_ENTRY_H

#ifdef __ASSEMBLER__

#include <asm/processor.h>
#include <asm/registers.h>
#include <asm/asm-offsets.h>

/*
 * Standard Nios2 interrupt entry and exit macros.
 * Must be called with interrupts disabled.
 */
.macro SAVE_ALL
	rdctl	r24, estatus
	andi	r24, r24, ESTATUS_EU
	beq	r24, r0, 1f /* In supervisor mode, already on kernel stack */

	movia	r24, _current_thread	/* Switch to current kernel stack */
	ldw	r24, 0(r24)		/* using the thread_info */
	addi	r24, r24, THREAD_SIZE-PT_REGS_SIZE
	stw	sp, PT_SP(r24)		/* Save user stack before changing */
	mov	sp, r24
	br	2f

1 :	mov	r24, sp
	addi	sp, sp, -PT_REGS_SIZE	/* Backup the kernel stack pointer */
	stw	r24, PT_SP(sp)
2 :	stw	r1, PT_R1(sp)
	stw	r2, PT_R2(sp)
	stw	r3, PT_R3(sp)
	stw	r4, PT_R4(sp)
	stw	r5, PT_R5(sp)
	stw	r6, PT_R6(sp)
	stw	r7, PT_R7(sp)
	stw	r8, PT_R8(sp)
	stw	r9, PT_R9(sp)
	stw	r10, PT_R10(sp)
	stw	r11, PT_R11(sp)
	stw	r12, PT_R12(sp)
	stw	r13, PT_R13(sp)
	stw	r14, PT_R14(sp)
	stw	r15, PT_R15(sp)
	movi	r24, -1
	stw	r24, PT_ORIG_R2(sp)
	stw	r7, PT_ORIG_R7(sp)

	stw	ra, PT_RA(sp)
	stw	fp, PT_FP(sp)
	stw	gp, PT_GP(sp)
	rdctl	r24, estatus
	stw	r24, PT_ESTATUS(sp)
	stw	ea, PT_EA(sp)
.endm

.macro RESTORE_ALL
	ldw	r1, PT_R1(sp)		/* Restore registers */
	ldw	r2, PT_R2(sp)
	ldw	r3, PT_R3(sp)
	ldw	r4, PT_R4(sp)
	ldw	r5, PT_R5(sp)
	ldw	r6, PT_R6(sp)
	ldw	r7, PT_R7(sp)
	ldw	r8, PT_R8(sp)
	ldw	r9, PT_R9(sp)
	ldw	r10, PT_R10(sp)
	ldw	r11, PT_R11(sp)
	ldw	r12, PT_R12(sp)
	ldw	r13, PT_R13(sp)
	ldw	r14, PT_R14(sp)
	ldw	r15, PT_R15(sp)
	ldw	ra, PT_RA(sp)
	ldw	fp, PT_FP(sp)
	ldw	gp, PT_GP(sp)
	ldw	r24, PT_ESTATUS(sp)
	wrctl	estatus, r24
	ldw	ea, PT_EA(sp)
	ldw	sp, PT_SP(sp)		/* Restore sp last */
.endm

.macro	SAVE_SWITCH_STACK
	addi	sp, sp, -SWITCH_STACK_SIZE
	stw	r16, SW_R16(sp)
	stw	r17, SW_R17(sp)
	stw	r18, SW_R18(sp)
	stw	r19, SW_R19(sp)
	stw	r20, SW_R20(sp)
	stw	r21, SW_R21(sp)
	stw	r22, SW_R22(sp)
	stw	r23, SW_R23(sp)

Annotation

Implementation Notes