Re: [Qemu-arm] [PATCH 1/5] hw/intc/exynos4210_gic: Fix GIC memory mappings for secondary CPU

[Peter Maydell]

On 1 March 2017 at 18:26, Krzysztof Kozlowski <address@hidden> wrote:
> Recent Linux kernel (tested next-20170224) was complaining about missing
> GIC mask and was unable to bring up secondary CPU:
>
>     [    0.000000] NR_IRQS:16 nr_irqs:16 16
>     [    0.000000] GIC CPU mask not found - kernel will fail to boot.
>     ...
>     [    0.400492] smp: Bringing up secondary CPUs ...
>     [    1.413184] CPU1: failed to boot: -110
>     [    1.423981] smp: Brought up 1 node, 1 CPU
>
> In its instance_init() call, the Exynos GIC driver was setting GIC
> memory mappings for each CPU, from 1 up to "num-cpu" property.  The
> Exynos4210 machine init call on the other hand, first created Exynos GIC
> device and then set the "num-cpu" property which was too late.  The init
> already happened with default "num-cpu" value of 1 thus GIC mappings
> were created only for the first CPU.
>
> Split the Exynos GIC init code into realize function so the code will
> see updated "num-cpu" property.  This fixes the warning and brings
> second CPU:
>     [    0.435780] CPU1: thread -1, cpu 1, socket 9, mpidr 80000901
>     [    0.451838] smp: Brought up 1 node, 2 CPUs
>
> Signed-off-by: Krzysztof Kozlowski <address@hidden>
> ---
>
> But please read cover letter!
>
> ---
>  hw/intc/exynos4210_gic.c | 24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)
>
> diff --git a/hw/intc/exynos4210_gic.c b/hw/intc/exynos4210_gic.c
> index 2a55817b7660..5986e54d39c9 100644
> --- a/hw/intc/exynos4210_gic.c
> +++ b/hw/intc/exynos4210_gic.c
> @@ -283,9 +283,19 @@ static void exynos4210_gic_set_irq(void *opaque, int 
> irq, int level)
>
>  static void exynos4210_gic_init(Object *obj)
>  {
> -    DeviceState *dev = DEVICE(obj);
>      Exynos4210GicState *s = EXYNOS4210_GIC(obj);
> -    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
> +
> +    memory_region_init(&s->cpu_container, obj, "exynos4210-cpu-container",
> +            EXYNOS4210_EXT_GIC_CPU_REGION_SIZE);
> +    memory_region_init(&s->dist_container, obj, "exynos4210-dist-container",
> +            EXYNOS4210_EXT_GIC_DIST_REGION_SIZE);
> +
> +}
> +
> +static void exynos4210_gic_realize(DeviceState *dev, Error **errp)
> +{
> +    Exynos4210GicState *s = EXYNOS4210_GIC(dev);
> +    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
>      uint32_t i;
>      const char cpu_prefix[] = "exynos4210-gic-alias_cpu";
>      const char dist_prefix[] = "exynos4210-gic-alias_dist";
> @@ -306,15 +316,10 @@ static void exynos4210_gic_init(Object *obj)
>      qdev_init_gpio_in(dev, exynos4210_gic_set_irq,
>                        EXYNOS4210_GIC_NIRQ - 32);
>
> -    memory_region_init(&s->cpu_container, obj, "exynos4210-cpu-container",
> -            EXYNOS4210_EXT_GIC_CPU_REGION_SIZE);
> -    memory_region_init(&s->dist_container, obj, "exynos4210-dist-container",
> -            EXYNOS4210_EXT_GIC_DIST_REGION_SIZE);
> -
>      for (i = 0; i < s->num_cpu; i++) {
>          /* Map CPU interface per SMP Core */
>          sprintf(cpu_alias_name, "%s%x", cpu_prefix, i);
> -        memory_region_init_alias(&s->cpu_alias[i], obj,
> +        memory_region_init_alias(&s->cpu_alias[i], OBJECT(s),
>                                   cpu_alias_name,
>                                   sysbus_mmio_get_region(busdev, 1),
>                                   0,
> @@ -324,7 +329,7 @@ static void exynos4210_gic_init(Object *obj)
>
>          /* Map Distributor per SMP Core */
>          sprintf(dist_alias_name, "%s%x", dist_prefix, i);
> -        memory_region_init_alias(&s->dist_alias[i], obj,
> +        memory_region_init_alias(&s->dist_alias[i], OBJECT(s),
>                                   dist_alias_name,
>                                   sysbus_mmio_get_region(busdev, 0),
>                                   0,

Slightly better to define
  Object *obj = OBJECT(dev);
at the start of the realize function rather than doing the dynamic
cast twice every time round the loop.

> @@ -346,6 +351,7 @@ static void exynos4210_gic_class_init(ObjectClass *klass, 
> void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
>
> +    dc->realize = exynos4210_gic_realize;
>      dc->props = exynos4210_gic_properties;
>  }

Otherwise
Reviewed-by: Peter Maydell <address@hidden>

thanks
-- PMM