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

[Dongdong Liu]

Hi Tomasz

å 2016/11/22 20:32, Tomasz Nowicki åé:
> 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.

 acpi_dev_free_resource_list
	--->resource_list_free
		--->resource_list_destroy_entry
			--->resource_list_free_entry
				--->kfree(entry)
only free entry not free entry->res, so this is ok.

Thanks
Dongdong
> > +    return res;
> > +}
>
>
> We either allocate memory for res here or get it from the caller.
>
> Tomasz
>
> .