Re: [Qemu-devel] [PATCH 1/2] hw/exynos4210_gic.c: Introduce n_in and n_out propeties.

[Peter Maydell]

On 11 April 2012 08:48, Evgeny Voevodin <address@hidden> wrote:
> With these properties irq gate could be tuned to mux up to
> QDEV_MAX_IRQ inputs and ouputs. Gate will group inputs
> into groups of size n_in/n_out each.
>
> Signed-off-by: Evgeny Voevodin <address@hidden>
> ---
>  hw/exynos4210_gic.c |   60 ++++++++++++++++++++++++++++++++------------------
>  1 files changed, 38 insertions(+), 22 deletions(-)
>
> diff --git a/hw/exynos4210_gic.c b/hw/exynos4210_gic.c
> index ec13140..1fe8225 100644
> --- a/hw/exynos4210_gic.c
> +++ b/hw/exynos4210_gic.c
> @@ -361,18 +361,29 @@ type_init(exynos4210_gic_register_types)
>  typedef struct {
>     SysBusDevice busdev;
>
> -    qemu_irq pic_irq[NCPU]; /* output IRQs to PICs */
> -    uint32_t gpio_level[EXYNOS4210_IRQ_GATE_NINPUTS]; /* Input levels */
> +    qemu_irq out[QDEV_MAX_IRQ]; /* output IRQs */
> +    uint32_t n_out;             /* outputs amount */
> +    uint32_t gpio_level[QDEV_MAX_IRQ]; /* Input levels */
> +    uint32_t n_in;              /* inputs amount */
> +    uint32_t group_size;         /* input group size */
>  } Exynos4210IRQGateState;
>
> +static Property exynos4210_irq_gate_properties[] = {
> +    DEFINE_PROP_UINT32("n_out", Exynos4210IRQGateState, n_out, 1),
> +    DEFINE_PROP_UINT32("n_in", Exynos4210IRQGateState, n_in, 1),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
>  static const VMStateDescription vmstate_exynos4210_irq_gate = {
>     .name = "exynos4210.irq_gate",
>     .version_id = 1,
>     .minimum_version_id = 1,
>     .minimum_version_id_old = 1,
>     .fields = (VMStateField[]) {
> -        VMSTATE_UINT32_ARRAY(gpio_level, Exynos4210IRQGateState,
> -                EXYNOS4210_IRQ_GATE_NINPUTS),
> +        VMSTATE_UINT32(n_out, Exynos4210IRQGateState),
> +        VMSTATE_UINT32_ARRAY(gpio_level, Exynos4210IRQGateState, 
> QDEV_MAX_IRQ),
> +        VMSTATE_UINT32(n_in, Exynos4210IRQGateState),
> +        VMSTATE_UINT32(group_size, Exynos4210IRQGateState),

VMState field changes require a version bump. I think we can forget
backcompatibility in this case, so just set all of version_id,
minumum_version_id and minimum_version_id_old to 2.

>         VMSTATE_END_OF_LIST()
>     }
>  };
> @@ -382,25 +393,24 @@ static void exynos4210_irq_gate_handler(void *opaque, 
> int irq, int level)
>  {
>     Exynos4210IRQGateState *s =
>             (Exynos4210IRQGateState *)opaque;
> -    uint32_t odd, even;
> -
> -    if (irq & 1) {
> -        odd = irq;
> -        even = irq & ~1;
> -    } else {
> -        even = irq;
> -        odd = irq | 1;
> -    }
> +    uint32_t n_out, n_group, i;
> +
> +    assert(irq < s->n_in);
> +
> +    n_out = irq / s->group_size;
> +    n_group = n_out * s->group_size;
>
> -    assert(irq < EXYNOS4210_IRQ_GATE_NINPUTS);
>     s->gpio_level[irq] = level;
>
> -    if (s->gpio_level[odd] >= 1 || s->gpio_level[even] >= 1) {
> -        qemu_irq_raise(s->pic_irq[even >> 1]);
> -    } else {
> -        qemu_irq_lower(s->pic_irq[even >> 1]);
> +    for (i = 0; i < s->group_size; i++) {
> +        if (s->gpio_level[n_group + i] >= 1) {
> +            qemu_irq_raise(s->out[n_out]);
> +            return;
> +        }
>     }
>
> +    qemu_irq_lower(s->out[n_out]);
> +
>     return;
>  }
>
> @@ -420,14 +430,19 @@ static int exynos4210_irq_gate_init(SysBusDevice *dev)
>     Exynos4210IRQGateState *s =
>             FROM_SYSBUS(Exynos4210IRQGateState, dev);
>
> +    /* Gate will make each input group of size n_in / n_out */
> +    assert((s->n_in % s->n_out) == 0);

The right way to check for validity of properties in the init
function is to use hw_error() with a reasonably friendly message.

> +
> +    s->group_size = s->n_in / s->n_out;
> +
>     /* Allocate general purpose input signals and connect a handler to each of
>      * them */
>     qdev_init_gpio_in(&s->busdev.qdev, exynos4210_irq_gate_handler,
> -            EXYNOS4210_IRQ_GATE_NINPUTS);
> +            s->n_in);

I think this whole function call will fit on a single line without
going over the 80 column limit now.

-- PMM