Re: [Qemu-devel] [PATCH v11 02/19] i.MX: Move serial initialization to init/realize of DeviceClass.

[Peter Crosthwaite]

On Wed, Jul 8, 2015 at 10:55 PM, Jean-Christophe DUBOIS
<address@hidden> wrote:
> Le 08/07/2015 22:49, Peter Crosthwaite a écrit :
>>
>> On Wed, Jul 8, 2015 at 11:42 AM, Jean-Christophe Dubois
>> <address@hidden> wrote:
>>>
>>> Move constructor to DeviceClass methods
>>>   * imx_serial_init
>>>   * imx_serial_realize
>>>
>>> imx32_serial_properties is renamed to imx_serial_properties.
>>>
>>> Rework of Qdev construction helper function.
>>>
>>> Signed-off-by: Jean-Christophe Dubois <address@hidden>
>>> ---
>>>
>>> Changes since v1:
>>>      * not present on v1
>>>
>>> Changes since v2:
>>>      * not present on v2
>>>
>>> Changes since v3:
>>>      * not present on v3
>>>
>>> Changes since v4:
>>>      * not present on v4
>>>
>>> Changes since v5:
>>>      * not present on v5
>>>
>>> Changes since v6:
>>>      * not present on v6
>>>
>>> Changes since v7:
>>>      * not present on v7
>>>
>>> Changes since v8:
>>>      * Remove Qdev construction helper
>>>
>>> Changes since v9:
>>>      * Qdev construction helper is reintegrated and moved to a header
>>> file
>>>        as an inline function.
>>>
>>> Changes since v10:
>>>      * Qdev construction helper is put back in the main file.
>>>      * Qdev construction helper is reworked
>>>      * We don't use qemu_char_get_next_serial() anymore but the chardev
>>>        property instead.
>>>      * Fix code to work with an unitialized (null) chardev property
>>>
>>>   hw/char/imx_serial.c | 98
>>> +++++++++++++++++++++++++++++-----------------------
>>>   1 file changed, 54 insertions(+), 44 deletions(-)
>>>
>>> diff --git a/hw/char/imx_serial.c b/hw/char/imx_serial.c
>>> index 1dcb325..950c740 100644
>>> --- a/hw/char/imx_serial.c
>>> +++ b/hw/char/imx_serial.c
>>> @@ -38,13 +38,13 @@ do { printf("imx_serial: " fmt , ##args); } while (0)
>>>   //#define DEBUG_IMPLEMENTATION 1
>>>   #ifdef DEBUG_IMPLEMENTATION
>>>   #  define IPRINTF(fmt, args...) \
>>> -    do  { fprintf(stderr, "imx_serial: " fmt, ##args); } while (0)
>>> +    do  { fprintf(stderr, "%s: " fmt, TYPE_IMX_SERIAL, ##args); } while
>>> (0)
>>>   #else
>>>   #  define IPRINTF(fmt, args...) do {} while (0)
>>>   #endif
>>>
>>>   static const VMStateDescription vmstate_imx_serial = {
>>> -    .name = "imx-serial",
>>> +    .name = TYPE_IMX_SERIAL,
>>>       .version_id = 1,
>>>       .minimum_version_id = 1,
>>>       .fields = (VMStateField[]) {
>>> @@ -125,7 +125,9 @@ static uint64_t imx_serial_read(void *opaque, hwaddr
>>> offset,
>>>               s->usr2 &= ~USR2_RDR;
>>>               s->uts1 |= UTS1_RXEMPTY;
>>>               imx_update(s);
>>> -            qemu_chr_accept_input(s->chr);
>>> +            if (s->chr) {
>>> +                qemu_chr_accept_input(s->chr);
>>> +            }
>>>           }
>>>           return c;
>>>
>>> @@ -212,7 +214,9 @@ static void imx_serial_write(void *opaque, hwaddr
>>> offset,
>>>           }
>>>           if (value & UCR2_RXEN) {
>>>               if (!(s->ucr2 & UCR2_RXEN)) {
>>> -                qemu_chr_accept_input(s->chr);
>>> +                if (s->chr) {
>>> +                    qemu_chr_accept_input(s->chr);
>>> +                }
>>
>> Looking around, imx serial is trying to be NULL safe except for these
>> two cases. This and the hunk above is a full-on bugfix that should
>> probably be split off and go to 2.4.
>
> How do you provide a patch specifically for 2.4 (beside including it in my
> series)?
>
>
>>
>>>               }
>>>           }
>>>           s->ucr2 = value & 0xffff;
>>> @@ -299,23 +303,16 @@ static void imx_event(void *opaque, int event)
>>>       }
>>>   }
>>>
>>> -
>>
>> Out of scope style change.
>>
>>>   static const struct MemoryRegionOps imx_serial_ops = {
>>>       .read = imx_serial_read,
>>>       .write = imx_serial_write,
>>>       .endianness = DEVICE_NATIVE_ENDIAN,
>>>   };
>>>
>>> -static int imx_serial_init(SysBusDevice *dev)
>>> +static void imx_serial_realize(DeviceState *dev, Error **errp)
>>>   {
>>>       IMXSerialState *s = IMX_SERIAL(dev);
>>>
>>> -
>>> -    memory_region_init_io(&s->iomem, OBJECT(s), &imx_serial_ops, s,
>>> -                          "imx-serial", 0x1000);
>>> -    sysbus_init_mmio(dev, &s->iomem);
>>> -    sysbus_init_irq(dev, &s->irq);
>>> -
>>>       if (s->chr) {
>>>           qemu_chr_add_handlers(s->chr, imx_can_receive, imx_receive,
>>>                                 imx_event, s);
>>> @@ -323,45 +320,58 @@ static int imx_serial_init(SysBusDevice *dev)
>>>           DPRINTF("No char dev for uart at 0x%lx\n",
>>>                   (unsigned long)s->iomem.ram_addr);
>>>       }
>>> +}
>>> +
>>> +static void imx_serial_init(Object *obj)
>>> +{
>>> +    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
>>> +    IMXSerialState *s = IMX_SERIAL(obj);
>>>
>>> -    return 0;
>>> +    memory_region_init_io(&s->iomem, obj, &imx_serial_ops, s,
>>> +                          TYPE_IMX_SERIAL, 0x1000);
>>> +    sysbus_init_mmio(sbd, &s->iomem);
>>> +    sysbus_init_irq(sbd, &s->irq);
>>>   }
>>>
>>>   void imx_serial_create(int uart, const hwaddr addr, qemu_irq irq)
>>>   {
>>>       DeviceState *dev;
>>> -    SysBusDevice *bus;
>>> -    CharDriverState *chr;
>>> -    const char chr_name[] = "serial";
>>> -    char label[ARRAY_SIZE(chr_name) + 1];
>>>
>>>       dev = qdev_create(NULL, TYPE_IMX_SERIAL);
>>>
>>> -    if (uart >= MAX_SERIAL_PORTS) {
>>> -        hw_error("Cannot assign uart %d: QEMU supports only %d ports\n",
>>> -                 uart, MAX_SERIAL_PORTS);
>>> -    }
>>> -    chr = serial_hds[uart];
>>> -    if (!chr) {
>>> -        snprintf(label, ARRAY_SIZE(label), "%s%d", chr_name, uart);
>>> -        chr = qemu_chr_new(label, "null", NULL);
>>> -        if (!(chr)) {
>>> -            hw_error("Can't assign serial port to imx-uart%d.\n", uart);
>>> +    if (dev) {
>>
>> If dev is NULL I think you have big problems. If there is a valid
>> reason why this can be NULL in a non-error case then it should just
>> short return.
>
>
> It is obviously an error case (out of resource?) and therefore we should not
> ignore it (as it was previously the case). So I test for it here. Do you
> feel there should be another behavior (hw_error or something)?
>
>
>>
>> if (!dev) {
>>      return;
>> }
>>
>>> +        SysBusDevice *bus;
>>> +
>>> +        if (uart < MAX_SERIAL_PORTS) {
>>> +            CharDriverState *chr;
>>> +
>>> +            chr = serial_hds[uart];
>>> +
>>> +            if (!chr) {
>>> +                char label[20];
>>> +                snprintf(label, sizeof(label), "imx.uart%d", uart);
>>> +                chr = qemu_chr_new(label, "null", NULL);
>>> +                if (!(chr)) {
>>> +                    hw_error("Can't assign serial port to %s.\n",
>>> label);
>>> +                }
>>> +            }
>>> +
>>> +            qdev_prop_set_chr(dev, "chardev", chr);
>>>           }
>>> -    }
>>>
>>> -    qdev_prop_set_chr(dev, "chardev", chr);
>>> -    bus = SYS_BUS_DEVICE(dev);
>>> -    qdev_init_nofail(dev);
>>> -    if (addr != (hwaddr)-1) {
>>> -        sysbus_mmio_map(bus, 0, addr);
>>> -    }
>>> -    sysbus_connect_irq(bus, 0, irq);
>>> +        bus = SYS_BUS_DEVICE(dev);
>>>
>>> -}
>>> +        qdev_init_nofail(dev);
>>> +
>>> +        if (addr != (hwaddr)-1) {
>>> +            sysbus_mmio_map(bus, 0, addr);
>>> +        }
>>>
>>> +        sysbus_connect_irq(bus, 0, irq);
>>> +    }
>>> +}
>>
>> So the change to _create looks correct, but it is still out of scope
>> of the patch which by commit message is an init/realize conversion. Is
>> there a reason the old _create implementation wont work with the new
>> init/realize and allow a split?
>>
>> Aside from the minor comments the code is good, but I would split this
>> to 3 patches.
>>
>> 1: chr NULL guards, and send that as a single for 2.4.
>> 2: realize and init conversion
>> 3: _create rewrite.
>
>
> OK, I'll do it even if I am spending quite some time on something that is
> going to be wiped out in a following patch.
>
>
>>
>> Regards,
>> Peter
>>
>>> -static Property imx32_serial_properties[] = {
>>> +static Property imx_serial_properties[] = {
>>>       DEFINE_PROP_CHR("chardev", IMXSerialState, chr),
>>>       DEFINE_PROP_END_OF_LIST(),
>>>   };
>>> @@ -369,21 +379,21 @@ static Property imx32_serial_properties[] = {
>>>   static void imx_serial_class_init(ObjectClass *klass, void *data)
>>>   {
>>>       DeviceClass *dc = DEVICE_CLASS(klass);
>>> -    SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
>>>
>>> -    k->init = imx_serial_init;
>>> +    dc->realize = imx_serial_realize;
>>>       dc->vmsd = &vmstate_imx_serial;
>>>       dc->reset = imx_serial_reset_at_boot;
>>>       set_bit(DEVICE_CATEGORY_INPUT, dc->categories);
>>>       dc->desc = "i.MX series UART";
>>> -    dc->props = imx32_serial_properties;
>>> +    dc->props = imx_serial_properties;
>>>   }
>>>
>>>   static const TypeInfo imx_serial_info = {
>>> -    .name = TYPE_IMX_SERIAL,
>>> -    .parent = TYPE_SYS_BUS_DEVICE,
>>> -    .instance_size = sizeof(IMXSerialState),
>>> -    .class_init = imx_serial_class_init,
>>> +    .name           = TYPE_IMX_SERIAL,
>>> +    .parent         = TYPE_SYS_BUS_DEVICE,
>>> +    .instance_size  = sizeof(IMXSerialState),
>>> +    .instance_init  = imx_serial_init,
>>> +    .class_init     = imx_serial_class_init,
>>>   };
>>>
>>>   static void imx_serial_register_types(void)
>>> --
>>> 2.1.4
>>>
>>>
>
>