/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Sleep helper for Loongson-3 sleep mode.
 *
 * Author: Huacai Chen <chenhuacai@loongson.cn>
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */

#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/addrspace.h>
#include <asm/loongarch.h>
#include <asm/stackframe.h>

/* preparatory stuff */
.macro  SETUP_SLEEP
        PTR_ADDI        sp, sp, -PT_SIZE
        REG_S           $r1, sp, PT_R1
        REG_S           $r2, sp, PT_R2
        REG_S           $r3, sp, PT_R3
        REG_S           $r4, sp, PT_R4
        REG_S           $r21, sp, PT_R21
        REG_S           $r22, sp, PT_R22
        REG_S           $r23, sp, PT_R23
        REG_S           $r24, sp, PT_R24
        REG_S           $r25, sp, PT_R25
        REG_S           $r26, sp, PT_R26
        REG_S           $r27, sp, PT_R27
        REG_S           $r28, sp, PT_R28
        REG_S           $r29, sp, PT_R29
        REG_S           $r30, sp, PT_R30
        REG_S           $r31, sp, PT_R31
.endm

.macro SETUP_WAKEUP
        REG_L           $r1, sp, PT_R1
        REG_L           $r2, sp, PT_R2
        REG_L           $r3, sp, PT_R3
        REG_L           $r4, sp, PT_R4
        REG_L           $r21, sp, PT_R21
        REG_L           $r22, sp, PT_R22
        REG_L           $r23, sp, PT_R23
        REG_L           $r24, sp, PT_R24
        REG_L           $r25, sp, PT_R25
        REG_L           $r26, sp, PT_R26
        REG_L           $r27, sp, PT_R27
        REG_L           $r28, sp, PT_R28
        REG_L           $r29, sp, PT_R29
        REG_L           $r30, sp, PT_R30
        REG_L           $r31, sp, PT_R31
        PTR_ADDI        sp, sp, PT_SIZE
.endm

        .text
        .align 12

/* Sleep/wakeup code for Loongson-3 */
SYM_FUNC_START(loongarch_suspend_enter)
        SETUP_SLEEP

        la.pcrel        t0, acpi_saved_sp
        REG_S           sp, t0, 0

        bl              __flush_cache_all

        /* Pass RA and SP to BIOS */
        PTR_ADDI        a1, sp, 0
        la.pcrel        a0, loongarch_wakeup_start
        la.pcrel        t0, loongarch_suspend_addr
        REG_L           t0, t0, 0
        jirl            ra, t0, 0 /* Call BIOS's STR sleep routine */

        /*
         * This is where we return upon wakeup.
         * Reload all of the registers and return.
         */
SYM_INNER_LABEL(loongarch_wakeup_start, SYM_L_GLOBAL)
        SETUP_DMWINS    t0
        JUMP_VIRT_ADDR  t0, t1

        /* Enable PG */
        li.w            t0, 0xb0                # PLV=0, IE=0, PG=1
        csrwr           t0, LOONGARCH_CSR_CRMD

        la.pcrel        t0, acpi_saved_sp
        REG_L           sp, t0, 0

        SETUP_WAKEUP
        jr              ra
SYM_FUNC_END(loongarch_suspend_enter)