Re: [PATCH V8 9/9] pci, acpi: ARM64 support for ACPI based generic PCI host controller

[Tomasz Nowicki]

On 02.06.2016 11:35, Lorenzo Pieralisi wrote:
> On Mon, May 30, 2016 at 05:14:22PM +0200, Tomasz Nowicki wrote:
> > This patch implements pci_acpi_scan_root call so that ARM64 can start
> > using ACPI to setup and enumerate PCI buses.
> >
> > The implementation of pci_acpi_scan_root() looks up config space regions
> > through MCFG interface. Then ECAM library is doing a new mapping
> > and attach generic ECAM ops which are used for accessing config space.
> >
> > On ARM64, ACPI and DT can be enabled together, and in that case
> > we need to use generic domains. In order to do that we implement
> > ARM64 specific way of retrieving domain number from pci_config_window
> > structure.
> >
> > Since we enable PCI for ACPI we need to implement raw_pci_{read|write}
> > at the same time. ARM64 provides RAW accessors as long as there is
> > correlated valid pci_bus structure, but not before.
> >
> > Signed-off-by: Tomasz Nowicki <tn@xxxxxxxxxxxx>
> > Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx>
>
> [...]
>
> > +/* release_info: free resrouces allocated by init_info */
>
> Nit: s/resrouces/resources
>
> > +static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
> > +{
> > +	struct acpi_pci_generic_root_info *ri;
> > +
> > +	ri = container_of(ci, struct acpi_pci_generic_root_info, common);
> > +	pci_ecam_free(ri->cfg);
> > +	kfree(ri);
> > +}
> > +
> > +static struct acpi_pci_root_ops acpi_pci_root_ops = {
> > +	.release_info = pci_acpi_generic_release_info,
> > +};
> > +
> > +/* Interface called from ACPI code to setup PCI host controller */
> >   struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
> >   {
> > -	/* TODO: Should be revisited when implementing PCI on ACPI */
> > -	return NULL;
> > +	int node = acpi_get_node(root->device->handle);
> > +	struct acpi_pci_generic_root_info *ri;
> > +	struct pci_bus *bus, *child;
> > +	int err;
> > +
> > +	ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
> > +	if (!ri)
> > +		return NULL;
> > +
> > +	err = pci_acpi_setup_ecam_mapping(root, ri);
> > +	if (err)
> > +		return NULL;
>                  ^
> Leaking memory -> kfree(ri)

I missed that. Will fix.

> > +	acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
> > +	bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
> > +				   ri->cfg);
> > +	if (!bus)
> > +		return NULL;
>
> Ditto.

Here kfree(ri) is not needed. __acpi_pci_root_release_info will free ri 
inside of acpi_pci_root_create.

> > +
> > +	pci_bus_size_bridges(bus);
> > +	pci_bus_assign_resources(bus);
> > +
> > +	list_for_each_entry(child, &bus->children, node)
> > +		pcie_bus_configure_settings(child);
> > +
> > +	return bus;
> >   }
> >
> >   void pcibios_add_bus(struct pci_bus *bus)
> > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > index 9661c85..f66d188 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -1390,7 +1390,12 @@ static inline int pci_domain_nr(struct pci_bus *bus)
> >   {
> >   	return bus->domain_nr;
> >   }
> > +/* Arch specific ACPI hook to set-up domain number */
> > +#ifdef CONFIG_ACPI
> > +int acpi_pci_bus_domain_nr(struct pci_bus *bus);
>
> Technically speaking, this should be introduced in a separate patch;
> given that I know it is a temporary plaster and no other architecture will
> have to implement it I reckon it is fine to leave it here, I will make
> it disappear as fast as I can.
>
> We can argue if it is best to move the ACPI bits into a separate file
> (acpi-pci.c), I am fine with keeping DT/ACPI in one file if that's fine
> with Catalin and Will.
>
> You can send the fix-ups above in the final pull request which I hope
> is nigh.
>
> Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>

Thanks,
Tomasz