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 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.

>              }
>          }
>          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.

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.

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
>
>