/*
 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
 * Copyright (C) 2004 Microtronix Datacom Ltd.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#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)
        stw     fp, SW_FP(sp)
        stw     gp, SW_GP(sp)
        stw     ra, SW_RA(sp)
.endm

.macro  RESTORE_SWITCH_STACK
        ldw     r16, SW_R16(sp)
        ldw     r17, SW_R17(sp)
        ldw     r18, SW_R18(sp)
        ldw     r19, SW_R19(sp)
        ldw     r20, SW_R20(sp)
        ldw     r21, SW_R21(sp)
        ldw     r22, SW_R22(sp)
        ldw     r23, SW_R23(sp)
        ldw     fp, SW_FP(sp)
        ldw     gp, SW_GP(sp)
        ldw     ra, SW_RA(sp)
        addi    sp, sp, SWITCH_STACK_SIZE
.endm

#endif /* __ASSEMBLER__ */
#endif /* _ASM_NIOS2_ENTRY_H */