QEMU ARM interrupt system architecture 2

I'd like to list the log here to help the understand of the process.

GPIO_IN initialize API is :

void qdev_init_gpio_in(DeviceState *dev, qemu_irq_handler handler, int n)
{
    qdev_init_gpio_in_named(dev, handler, NULL, n);
}

static inline void qdev_init_gpio_in_named(DeviceState *dev,
                                           qemu_irq_handler handler,
                                           const char *name, int n)
{
    qdev_init_gpio_in_named_with_opaque(dev, handler, dev, name, n);
}

void qdev_init_gpio_in_named_with_opaque(DeviceState *dev,
                                         qemu_irq_handler handler,
                                         void *opaque,
                                         const char *name, int n)
{
    int i;
    NamedGPIOList *gpio_list = qdev_get_named_gpio_list(dev, name);

    assert(gpio_list->num_out == 0 || !name);
    gpio_list->in = qemu_extend_irqs(gpio_list->in, gpio_list->num_in, handler,
                                     opaque, n);
    .....
    gpio_list->num_in += n;
}

qemu_irq *qemu_extend_irqs(qemu_irq *old, int n_old, qemu_irq_handler handler,
                           void *opaque, int n)
{
    qemu_irq *s;
    int i;

    if (!old) {
        n_old = 0;
    }
    s = old ? g_renew(qemu_irq, old, n + n_old) : g_new(qemu_irq, n);
    for (i = n_old; i < n + n_old; i++) {
        s[i] = qemu_allocate_irq(handler, opaque, i);
    }
    return s;
}

qemu_irq qemu_allocate_irq(qemu_irq_handler handler, void *opaque, int n)
{
    struct IRQState *irq;
    
    irq = IRQ(object_new(TYPE_IRQ));
    irq->handler = handler;
    irq->opaque = opaque;
    irq->n = n;
    printf("alexdebug:%s irq at %p, n is %d\n",__func__,irq,n);
    return irq;
}

1. ARM CORE GPIO_IN irq creation.

static void arm_cpu_initfn(Object *obj)
{
    ARMCPU *cpu = ARM_CPU(obj);
    .....
    qdev_init_gpio_in(DEVICE(cpu), arm_cpu_set_irq, 4);
    .....
}

The log is:

alexdebug:qemu_allocate_irq irq at 0x7fffbe6b4480, n is 0
alexdebug:qemu_allocate_irq irq at 0x7fffbe6644c0, n is 1
alexdebug:qemu_allocate_irq irq at 0x7fffbe6702c0, n is 2
alexdebug:qemu_allocate_irq irq at 0x7fffbe66fbe0, n is 3

2. GIC GPIO_IN irq creation

static void arm_gic_realize(DeviceState *dev, Error **errp)
{
    GICState *s = ARM_GIC(dev);
    .....
    gic_init_irqs_and_mmio(s, gic_set_irq, gic_ops, gic_virt_ops);
    .....
}

void gic_init_irqs_and_mmio(GICState *s, qemu_irq_handler handler,
                            const MemoryRegionOps *ops,
                            const MemoryRegionOps *virt_ops)
{
    SysBusDevice *sbd = SYS_BUS_DEVICE(s);
    int i = s->num_irq - GIC_INTERNAL;

    /* For the GIC, also expose incoming GPIO lines for PPIs for each CPU.
     * GPIO array layout is thus:
     *  [0..N-1] SPIs
     *  [N..N+31] PPIs for CPU 0
     *  [N+32..N+63] PPIs for CPU 1
     *   ...
     */
    i += (GIC_INTERNAL * s->num_cpu);
    qdev_init_gpio_in(DEVICE(s), handler, i);

    for (i = 0; i < s->num_cpu; i++) {
        sysbus_init_irq(sbd, &s->parent_irq[i]);
    }
    for (i = 0; i < s->num_cpu; i++) {
        sysbus_init_irq(sbd, &s->parent_fiq[i]);
    }
    for (i = 0; i < s->num_cpu; i++) {
        sysbus_init_irq(sbd, &s->parent_virq[i]);
    }
    for (i = 0; i < s->num_cpu; i++) {
        sysbus_init_irq(sbd, &s->parent_vfiq[i]);
    }
    .....
}

The log is:

alexdebug:arm_gic_realize
alexdebug:arm_gic_common_realize begin, SysBusDevice is at 0x7fffbe7a9ce0
alexdebug:qemu_allocate_irq irq at 0x7fffbe6627b0, n is 0
alexdebug:qemu_allocate_irq irq at 0x7fffbe662900, n is 1
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b47a0, n is 2
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4840, n is 3
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4910, n is 4
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b49e0, n is 5
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4ab0, n is 6
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4b80, n is 7
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4c50, n is 8
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4d20, n is 9
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4df0, n is 10
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4ec0, n is 11
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b4f90, n is 12
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5060, n is 13
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5130, n is 14
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5200, n is 15
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b52d0, n is 16
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b53a0, n is 17
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5ca0, n is 18
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5d70, n is 19
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5e40, n is 20
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5f10, n is 21
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b5fe0, n is 22
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b60b0, n is 23
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6180, n is 24
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6250, n is 25
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6320, n is 26
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b63f0, n is 27
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b64c0, n is 28
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6590, n is 29
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6660, n is 30
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6730, n is 31
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6800, n is 32
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b68d0, n is 33
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b69a0, n is 34
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6a70, n is 35
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b6b40, n is 36
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b7a80, n is 37
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b7b50, n is 38
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b7c20, n is 39
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b7cf0, n is 40
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b7dc0, n is 41
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b7e90, n is 42
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b7f60, n is 43
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b8030, n is 44
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b8100, n is 45
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b81d0, n is 46
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b82a0, n is 47
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b8370, n is 48
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b8440, n is 49
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b8510, n is 50
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b85e0, n is 51
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b86b0, n is 52
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b8780, n is 53
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b96e0, n is 54
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b97b0, n is 55
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9880, n is 56
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9950, n is 57
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9a20, n is 58
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9af0, n is 59
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9bc0, n is 60
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9c90, n is 61
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9d60, n is 62
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9e30, n is 63
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9f00, n is 64
alexdebug:qemu_allocate_irq irq at 0x7fffbe7b9fd0, n is 65
alexdebug:qemu_allocate_irq irq at 0x7fffbe7ba0a0, n is 66
alexdebug:qemu_allocate_irq irq at 0x7fffbe7ba170, n is 67
alexdebug:qemu_allocate_irq irq at 0x7fffbe7ba240, n is 68
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb370, n is 69
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb440, n is 70
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb510, n is 71
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb5e0, n is 72
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb6b0, n is 73
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb780, n is 74
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb850, n is 75
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb920, n is 76
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bb9f0, n is 77
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bbac0, n is 78
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bbb90, n is 79
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bbc60, n is 80
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bbd30, n is 81
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bbe00, n is 82
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bbed0, n is 83
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bbfa0, n is 84
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bc070, n is 85
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bc970, n is 86
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bca40, n is 87
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bcb10, n is 88
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bcbe0, n is 89
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bccb0, n is 90
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bcd80, n is 91
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bce50, n is 92
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bcf20, n is 93
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bcff0, n is 94
alexdebug:qemu_allocate_irq irq at 0x7fffbe7bd0c0, n is 95

3. timer GPIO_OUT irq connect to GIC GPIO_IN irq

static void a9mp_priv_realize(DeviceState *dev, Error **errp)
{
    .....
    A9MPPrivState *s = A9MPCORE_PRIV(dev);
    .....
    gicdev = DEVICE(&s->gic);
    .....
    gtimerbusdev = SYS_BUS_DEVICE(&s->gtimer);
    .....
    mptimerbusdev = SYS_BUS_DEVICE(&s->mptimer);
    .....
    wdtbusdev = SYS_BUS_DEVICE(&s->wdt);
    .....
    for (i = 0; i < s->num_cpu; i++) {
        int ppibase = (s->num_irq - 32) + i * 32;
        sysbus_connect_irq(gtimerbusdev, i,
                           qdev_get_gpio_in(gicdev, ppibase + 27));
        sysbus_connect_irq(mptimerbusdev, i,
                           qdev_get_gpio_in(gicdev, ppibase + 29));
        sysbus_connect_irq(wdtbusdev, i,
                           qdev_get_gpio_in(gicdev, ppibase + 30));
    }
}

Log is:

alexdebug:sysbus_connect_irq -------start --device arm.cortex-a9-global-timer --cpu is 0 , irq at 0x7fffbe7bcd80, irq->n is 91 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:sysbus_connect_irq -------start --device arm_mptimer --cpu is 0 , irq at 0x7fffbe7bcf20, irq->n is 93 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:sysbus_connect_irq -------start --device arm_mptimer --cpu is 0 , irq at 0x7fffbe7bcff0, irq->n is 94 ---
alexdebug:sysbus_connect_irq -------end -------

We can see irq 91 is GIC 91 GPIO_IRQ(0x7fffbe7bcd80). 93,94 irqs are GIC 93,94 irq too.

4. PIC[] from GIC

static void vexpress_common_init(MachineState *machine)
{
    qemu_irq pic[64];
    .....
    daughterboard->init(vms, machine->ram_size, machine->cpu_type, pic);
}

static void a9_daughterboard_init(const VexpressMachineState *vms,
                                  ram_addr_t ram_size,
                                  const char *cpu_type,
                                  qemu_irq *pic)
{
    init_cpus(machine, cpu_type, TYPE_A9MPCORE_PRIV, 0x1e000000, pic,
              vms->secure, vms->virt);
}

static void init_cpus(MachineState *ms, const char *cpu_type,
                      const char *privdev, hwaddr periphbase,
                      qemu_irq *pic, bool secure, bool virt)
{
    DeviceState *dev;
    SysBusDevice *busdev;
    A9MPPrivState *a9_s;
    int n;
    .....
    {
    a9_s = A9MPCORE_PRIV(dev);
    printf("alexdebug:%s, GIC parent_irq at %p\n",__func__,a9_s->gic.parent_irq[0]);
    }
    for (n = 0; n < 64; n++) {
    	 DeviceState* gicdev=DEVICE(&a9_s->gic);
        pic[n] = qdev_get_gpio_in(gicdev, n);
        //pic[n] = qdev_get_gpio_in(dev, n);
        printf("alexxie:%s, pic[%d] at %p\n",__func__,n,pic[n]);
    }
    .....
}

Log is:

alexdebug:init_cpus, GIC parent_irq at (nil)
alexxie:init_cpus, pic[0] at 0x7fffbe6627b0
alexxie:init_cpus, pic[1] at 0x7fffbe662900
alexxie:init_cpus, pic[2] at 0x7fffbe7b47a0
alexxie:init_cpus, pic[3] at 0x7fffbe7b4840
alexxie:init_cpus, pic[4] at 0x7fffbe7b4910
alexxie:init_cpus, pic[5] at 0x7fffbe7b49e0
alexxie:init_cpus, pic[6] at 0x7fffbe7b4ab0
alexxie:init_cpus, pic[7] at 0x7fffbe7b4b80
alexxie:init_cpus, pic[8] at 0x7fffbe7b4c50
alexxie:init_cpus, pic[9] at 0x7fffbe7b4d20
alexxie:init_cpus, pic[10] at 0x7fffbe7b4df0
alexxie:init_cpus, pic[11] at 0x7fffbe7b4ec0
alexxie:init_cpus, pic[12] at 0x7fffbe7b4f90
alexxie:init_cpus, pic[13] at 0x7fffbe7b5060
alexxie:init_cpus, pic[14] at 0x7fffbe7b5130
alexxie:init_cpus, pic[15] at 0x7fffbe7b5200
alexxie:init_cpus, pic[16] at 0x7fffbe7b52d0
alexxie:init_cpus, pic[17] at 0x7fffbe7b53a0
alexxie:init_cpus, pic[18] at 0x7fffbe7b5ca0
alexxie:init_cpus, pic[19] at 0x7fffbe7b5d70
alexxie:init_cpus, pic[20] at 0x7fffbe7b5e40
alexxie:init_cpus, pic[21] at 0x7fffbe7b5f10
alexxie:init_cpus, pic[22] at 0x7fffbe7b5fe0
alexxie:init_cpus, pic[23] at 0x7fffbe7b60b0
alexxie:init_cpus, pic[24] at 0x7fffbe7b6180
alexxie:init_cpus, pic[25] at 0x7fffbe7b6250
alexxie:init_cpus, pic[26] at 0x7fffbe7b6320
alexxie:init_cpus, pic[27] at 0x7fffbe7b63f0
alexxie:init_cpus, pic[28] at 0x7fffbe7b64c0
alexxie:init_cpus, pic[29] at 0x7fffbe7b6590
alexxie:init_cpus, pic[30] at 0x7fffbe7b6660
alexxie:init_cpus, pic[31] at 0x7fffbe7b6730
alexxie:init_cpus, pic[32] at 0x7fffbe7b6800
alexxie:init_cpus, pic[33] at 0x7fffbe7b68d0
alexxie:init_cpus, pic[34] at 0x7fffbe7b69a0
alexxie:init_cpus, pic[35] at 0x7fffbe7b6a70
alexxie:init_cpus, pic[36] at 0x7fffbe7b6b40
alexxie:init_cpus, pic[37] at 0x7fffbe7b7a80
alexxie:init_cpus, pic[38] at 0x7fffbe7b7b50
alexxie:init_cpus, pic[39] at 0x7fffbe7b7c20
alexxie:init_cpus, pic[40] at 0x7fffbe7b7cf0
alexxie:init_cpus, pic[41] at 0x7fffbe7b7dc0
alexxie:init_cpus, pic[42] at 0x7fffbe7b7e90
alexxie:init_cpus, pic[43] at 0x7fffbe7b7f60
alexxie:init_cpus, pic[44] at 0x7fffbe7b8030
alexxie:init_cpus, pic[45] at 0x7fffbe7b8100
alexxie:init_cpus, pic[46] at 0x7fffbe7b81d0
alexxie:init_cpus, pic[47] at 0x7fffbe7b82a0
alexxie:init_cpus, pic[48] at 0x7fffbe7b8370
alexxie:init_cpus, pic[49] at 0x7fffbe7b8440
alexxie:init_cpus, pic[50] at 0x7fffbe7b8510
alexxie:init_cpus, pic[51] at 0x7fffbe7b85e0
alexxie:init_cpus, pic[52] at 0x7fffbe7b86b0
alexxie:init_cpus, pic[53] at 0x7fffbe7b8780
alexxie:init_cpus, pic[54] at 0x7fffbe7b96e0
alexxie:init_cpus, pic[55] at 0x7fffbe7b97b0
alexxie:init_cpus, pic[56] at 0x7fffbe7b9880
alexxie:init_cpus, pic[57] at 0x7fffbe7b9950
alexxie:init_cpus, pic[58] at 0x7fffbe7b9a20
alexxie:init_cpus, pic[59] at 0x7fffbe7b9af0
alexxie:init_cpus, pic[60] at 0x7fffbe7b9bc0
alexxie:init_cpus, pic[61] at 0x7fffbe7b9c90
alexxie:init_cpus, pic[62] at 0x7fffbe7b9d60
alexxie:init_cpus, pic[63] at 0x7fffbe7b9e30

5. GIC GPIO_OUT irq connect to ARM CORE GPIO_IN irq

static void init_cpus(MachineState *ms, const char *cpu_type,
                      const char *privdev, hwaddr periphbase,
                      qemu_irq *pic, bool secure, bool virt)
{
    DeviceState *dev;
    SysBusDevice *busdev;
    int n;
    unsigned int smp_cpus = ms->smp.cpus;
    .....
    busdev = SYS_BUS_DEVICE(dev); /*here busdev is a9mpcore_priv*/
    .....
    for (n = 0; n < smp_cpus; n++) {
        DeviceState *cpudev = DEVICE(qemu_get_cpu(n));

        sysbus_connect_irq(busdev, n, qdev_get_gpio_in(cpudev, ARM_CPU_IRQ));
        sysbus_connect_irq(busdev, n + smp_cpus,
                           qdev_get_gpio_in(cpudev, ARM_CPU_FIQ));
        sysbus_connect_irq(busdev, n + 2 * smp_cpus,
                           qdev_get_gpio_in(cpudev, ARM_CPU_VIRQ));
        sysbus_connect_irq(busdev, n + 3 * smp_cpus,
                           qdev_get_gpio_in(cpudev, ARM_CPU_VFIQ));
    }
    .....
}

Log is:

alexdebug:sysbus_connect_irq -------start --device a9mpcore_priv --cpu is 0 , irq at 0x7fffbe6b4480, irq->n is 0 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:sysbus_connect_irq -------start --device a9mpcore_priv --cpu is 1 , irq at 0x7fffbe6644c0, irq->n is 1 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:sysbus_connect_irq -------start --device a9mpcore_priv --cpu is 2 , irq at 0x7fffbe6702c0, irq->n is 2 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:sysbus_connect_irq -------start --device a9mpcore_priv --cpu is 3 , irq at 0x7fffbe66fbe0, irq->n is 3 ---
alexdebug:sysbus_connect_irq -------end -------

ARM CORE GPIO_IN irq 0 is 0x7fffbe6b4480, GIC connect to ARM CORE.

6. Device GPIO_OUT irq connect to GIC GPIO_IN irq

static void vexpress_common_init(MachineState *machine)
{
    .....
    pl011_create(map[VE_UART0], pic[5], serial_hd(0));
    pl011_create(map[VE_UART1], pic[6], serial_hd(1));
    pl011_create(map[VE_UART2], pic[7], serial_hd(2));
    pl011_create(map[VE_UART3], pic[8], serial_hd(3));
    .....
}

The log is:

alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexdebug:sysbus_connect_irq -------start --device pl011 --cpu is 0 , irq at 0x7fffbe7b49e0, irq->n is 5 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:pl011_create, uart irq is at 0x7fffbe7b49e0,(nil),(nil),(nil),(nil),(nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexdebug:sysbus_connect_irq -------start --device pl011 --cpu is 0 , irq at 0x7fffbe7b4ab0, irq->n is 6 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:pl011_create, uart irq is at 0x7fffbe7b4ab0,(nil),(nil),(nil),(nil),(nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexdebug:sysbus_connect_irq -------start --device pl011 --cpu is 0 , irq at 0x7fffbe7b4b80, irq->n is 7 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:pl011_create, uart irq is at 0x7fffbe7b4b80,(nil),(nil),(nil),(nil),(nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexxie:pl011_init, uart irq at (nil)
alexdebug:sysbus_connect_irq -------start --device pl011 --cpu is 0 , irq at 0x7fffbe7b4c50, irq->n is 8 ---
alexdebug:sysbus_connect_irq -------end -------
alexdebug:pl011_create, uart irq is at 0x7fffbe7b4c50,(nil),(nil),(nil),(nil),(nil)

Here UART GPIO_OUT irq connect to GIC GPIO_IN 5,6,7,8 irq.