Re: [PATCH V6 1/2] PCI/ACPI: Provide acpi_get_rc_resources() for ARM64 platform

[Tomasz Nowicki]

Hi Dongdong,

On 22.11.2016 13:08, Dongdong Liu wrote:
> The acpi_get_rc_resources() is used to get the RC register address that can
> not be described in MCFG. It takes the _HID&segment to look for and returns
> the RC address resource. Use PNP0C02 devices to describe such RC address
> resource. Use _UID to match segment to tell which root bus the PNP0C02
> resource belong to.
>
> Signed-off-by: Dongdong Liu <liudongdong3@xxxxxxxxxx>
> Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> ---
>  drivers/pci/pci-acpi.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  drivers/pci/pci.h      |  4 +++
>  2 files changed, 73 insertions(+)
>
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index d966d47..76fd6f4 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -29,6 +29,75 @@
>  	0x91, 0x17, 0xea, 0x4d, 0x19, 0xc3, 0x43, 0x4d
>  };
>
> +#ifdef CONFIG_ARM64
> +static struct resource *acpi_get_rc_addr(struct acpi_device *adev)
> +{
> +	struct resource_entry *entry;
> +	struct list_head list;
> +	unsigned long flags;
> +	int ret;
> +	struct resource *res;
> +
> +	INIT_LIST_HEAD(&list);
> +	flags = IORESOURCE_MEM;
> +	ret = acpi_dev_get_resources(adev, &list,
> +				     acpi_dev_filter_resource_type_cb,
> +				     (void *) flags);
> +	if (ret <= 0)
> +		return NULL;
> +
> +	entry = list_first_entry(&list, struct resource_entry, node);
> +	res = entry->res;

You return "res" memory pointer and...

> +	acpi_dev_free_resource_list(&list);

free it here.

> +	return res;
> +}


We either allocate memory for res here or get it from the caller.

Tomasz