Re: [Qemu-arm] [RFC v2 6/8] hw: platform-bus: enable to map any memory region onto the platform-bus

[Peter Maydell]

On 29 January 2016 at 16:53, Eric Auger <address@hidden> wrote:
> The platform bus currently is used to map dynamically instantiable
> platform device MMIO regions. The platform bus also can be seen as a
> pool of free guest physical addresses. We would like to use that pool
> to allocate a contiguous reserved IOVA region usable for MSI message
> address IOMMU mapping.
>
> This patch introduces platform_bus_map_region which enables to map any
> memory region onto the platform bus.
>
> Signed-off-by: Eric Auger <address@hidden>
> ---
>  hw/core/platform-bus.c    | 26 ++++++++++++++++----------
>  include/hw/platform-bus.h |  7 +++++++
>  2 files changed, 23 insertions(+), 10 deletions(-)
>
> diff --git a/hw/core/platform-bus.c b/hw/core/platform-bus.c
> index aa55d01..7d0f5e0 100644
> --- a/hw/core/platform-bus.c
> +++ b/hw/core/platform-bus.c
> @@ -128,16 +128,14 @@ static void platform_bus_map_irq(PlatformBusDevice 
> *pbus, SysBusDevice *sbdev,
>      sysbus_connect_irq(sbdev, n, pbus->irqs[irqn]);
>  }
>
> -static void platform_bus_map_mmio(PlatformBusDevice *pbus, SysBusDevice 
> *sbdev,
> -                                  int n)
> +void platform_bus_map_region(PlatformBusDevice *pbus, MemoryRegion *mr)
>  {
> -    MemoryRegion *sbdev_mr = sysbus_mmio_get_region(sbdev, n);
> -    uint64_t size = memory_region_size(sbdev_mr);
> +    uint64_t size = memory_region_size(mr);
>      uint64_t alignment = (1ULL << (63 - clz64(size + size - 1)));
>      uint64_t off;
>      bool found_region = false;
>
> -    if (memory_region_is_mapped(sbdev_mr)) {
> +    if (memory_region_is_mapped(mr)) {
>          /* Region is already mapped, nothing to do */
>          return;
>      }
> @@ -154,13 +152,21 @@ static void platform_bus_map_mmio(PlatformBusDevice 
> *pbus, SysBusDevice *sbdev,
>      }
>
>      if (!found_region) {
> -        error_report("Platform Bus: Can not fit MMIO region of size %"PRIx64,
> -                     size);
> -        exit(1);
> +        error_setg(&error_fatal,
> +                   "Platform Bus: Can not fit region %s of size %"PRIx64,
> +                   mr->name, size);
>      }
>
> -    /* Map the device's region into our Platform Bus MMIO space */
> -    memory_region_add_subregion(&pbus->mmio, off, sbdev_mr);
> +    /* Map the region into our Platform Bus MMIO space */
> +    memory_region_add_subregion(&pbus->mmio, off, mr);
> +}
> +
> +static void platform_bus_map_mmio(PlatformBusDevice *pbus, SysBusDevice 
> *sbdev,
> +                                  int n)
> +{
> +    MemoryRegion *sbdev_mr = sysbus_mmio_get_region(sbdev, n);
> +
> +    platform_bus_map_region(pbus, sbdev_mr);
>  }
>
>  /*
> diff --git a/include/hw/platform-bus.h b/include/hw/platform-bus.h
> index bd42b83..ee19674 100644
> --- a/include/hw/platform-bus.h
> +++ b/include/hw/platform-bus.h
> @@ -54,4 +54,11 @@ int platform_bus_get_irqn(PlatformBusDevice *platform_bus, 
> SysBusDevice *sbdev,
>  hwaddr platform_bus_get_mmio_addr(PlatformBusDevice *pbus, SysBusDevice 
> *sbdev,
>                                    int n);
>
> +/**
> + * platform_bus_map_region: map a region into the platform bus

s/region/MemoryRegion/

> + * @pbus: platform bus handle
> + * @mr: memory region handle
> + */
> +void platform_bus_map_region(PlatformBusDevice *pbus, MemoryRegion *mr);
> +
>  #endif /* !HW_PLATFORM_BUS_H */
> --
> 1.9.1

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

thanks
-- PMM