/*
 * Copyright (c) 2013-2019, Huawei Technologies Co., Ltd. All rights reserved.
 * Copyright (c) 2020, Huawei Device Co., Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 *    conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list
 *    of conditions and the following disclaimer in the documentation and/or other materials
 *    provided with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used
 *    to endorse or promote products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "gic_common.h"
#include "los_hwi_pri.h"
#include "los_mp.h"

STATIC_ASSERT(OS_USER_HWI_MAX <= 1020, "hwi max is too large!");

#ifdef LOSCFG_PLATFORM_BSP_GIC_V2

STATIC UINT32 g_curIrqNum = 0; //记录当前中断号

#if (LOSCFG_KERNEL_SMP == YES)
/*
 * filter description
 *   0b00: forward to the cpu interfaces specified in cpu_mask
 *   0b01: forward to all cpu interfaces
 *   0b10: forward only to the cpu interface that request the irq
 *///SGI软件触发中断(Software Generated Interrupt)通常用于多核间通讯
STATIC VOID GicWriteSgi(UINT32 vector, UINT32 cpuMask, UINT32 filter)
{
    UINT32 val = ((filter & 0x3) << 24) | ((cpuMask & 0xFF) << 16) |
                 (vector & 0xF);

    GIC_REG_32(GICD_SGIR) = val;//写SGI寄存器
}
//向指定核发送核间中断
VOID HalIrqSendIpi(UINT32 target, UINT32 ipi)
{
    GicWriteSgi(ipi, target, 0);
}
//设置中断的亲和性，即设置中断在固定核响应（该函数仅在SMP模式下支持）
VOID HalIrqSetAffinity(UINT32 vector, UINT32 cpuMask)
{
    UINT32 offset = vector / 4;
    UINT32 index = vector & 0x3;

    GIC_REG_8(GICD_ITARGETSR(offset) + index) = cpuMask;
}
#endif
//获取当前中断号
UINT32 HalCurIrqGet(VOID)
{
    return g_curIrqNum;
}
//屏蔽中断
VOID HalIrqMask(UINT32 vector)
{
    if ((vector > OS_USER_HWI_MAX) || (vector < OS_USER_HWI_MIN)) {
        return;
    }

    GIC_REG_32(GICD_ICENABLER(vector / 32)) = 1U << (vector % 32);
}
//解除屏蔽
VOID HalIrqUnmask(UINT32 vector)
{
    if ((vector > OS_USER_HWI_MAX) || (vector < OS_USER_HWI_MIN)) {
        return;
    }

    GIC_REG_32(GICD_ISENABLER(vector >> 5)) = 1U << (vector % 32);
}
//挂起中断
VOID HalIrqPending(UINT32 vector)
{
    if ((vector > OS_USER_HWI_MAX) || (vector < OS_USER_HWI_MIN)) {
        return;
    }

    GIC_REG_32(GICD_ISPENDR(vector >> 5)) = 1U << (vector % 32);
}
//清除中断号对应的中断寄存器的状态位，此接口依赖中断控制器版本，非必需
VOID HalIrqClear(UINT32 vector)
{
    GIC_REG_32(GICC_EOIR) = vector;
}
//给每个CPU core初始化硬件中断
VOID HalIrqInitPercpu(VOID)
{
    /* unmask interrupts */	//取消中断屏蔽
    GIC_REG_32(GICC_PMR) = 0xFF;

    /* enable gic cpu interface */	//启用gic cpu接口
    GIC_REG_32(GICC_CTLR) = 1;
}
//硬件中断初始化
VOID HalIrqInit(VOID)
{
    UINT32 i;

    /* set externel interrupts to be level triggered, active low. */	//将外部中断设置为电平触发，低电平激活
    for (i = 32; i < OS_HWI_MAX_NUM; i += 16) {
        GIC_REG_32(GICD_ICFGR(i / 16)) = 0;
    }

    /* set externel interrupts to CPU 0 */	//将外部中断设置为CPU 0
    for (i = 32; i < OS_HWI_MAX_NUM; i += 4) {
        GIC_REG_32(GICD_ITARGETSR(i / 4)) = 0x01010101;
    }

    /* set priority on all interrupts */	//设置所有中断的优先级
    for (i = 0; i < OS_HWI_MAX_NUM; i += 4) {
        GIC_REG_32(GICD_IPRIORITYR(i / 4)) = GICD_INT_DEF_PRI_X4;
    }

    /* disable all interrupts. */			//禁用所有中断。
    for (i = 0; i < OS_HWI_MAX_NUM; i += 32) {
        GIC_REG_32(GICD_ICENABLER(i / 32)) = ~0;
    }

    HalIrqInitPercpu();//初始化当前CPU中断信息

    /* enable gic distributor control */
    GIC_REG_32(GICD_CTLR) = 1;//使能分发中断寄存器,该寄存器作用是允许给CPU发送中断信号

#if (LOSCFG_KERNEL_SMP == YES)
    /* register inter-processor interrupt *///注册核间中断,啥意思?就是CPU各核直接可以发送中断信号
    //处理器间中断允许一个CPU向系统其他的CPU发送中断信号，处理器间中断（IPI）不是通过IRQ线传输的，而是作为信号直接放在连接所有CPU本地APIC的总线上。
    LOS_HwiCreate(LOS_MP_IPI_WAKEUP, 0xa0, 0, OsMpWakeHandler, 0);//中断处理函数
    LOS_HwiCreate(LOS_MP_IPI_SCHEDULE, 0xa0, 0, OsMpScheduleHandler, 0);//中断处理函数
    LOS_HwiCreate(LOS_MP_IPI_HALT, 0xa0, 0, OsMpScheduleHandler, 0);//中断处理函数
#endif
}
//硬中断处理函数，这里由硬件触发,调用见于 ..\arch\arm\arm\src\los_dispatch.S
VOID HalIrqHandler(VOID)
{
    UINT32 iar = GIC_REG_32(GICC_IAR);//从中断确认寄存器获取中断ID号
    UINT32 vector = iar & 0x3FFU;//计算中断向量号

    /*
     * invalid irq number, mainly the spurious interrupts 0x3ff,
     * gicv2 valid irq ranges from 0~1019, we use OS_HWI_MAX_NUM
     * to do the checking.
     */
    if (vector >= OS_HWI_MAX_NUM) {
        return;
    }
    g_curIrqNum = vector;//记录当前中断ID号

    OsInterrupt(vector);//调用上层中断处理函数

    /* use orignal iar to do the EOI */
    GIC_REG_32(GICC_EOIR) = iar;//更新中断结束寄存器
}
//获取中断控制器版本
CHAR *HalIrqVersion(VOID)
{
    UINT32 pidr = GIC_REG_32(GICD_PIDR2V2);
    CHAR *irqVerString = NULL;

    switch (pidr >> GIC_REV_OFFSET) {
        case GICV1:
            irqVerString = "GICv1";
            break;
        case GICV2:
            irqVerString = "GICv2";
            break;
        default:
            irqVerString = "unknown";
    }
    return irqVerString;
}

#endif