[PATCH v8 8/9] pci: Add support for creating a generic host_bridge from device tree

[Liviu Dudau]

On Fri, Jul 11, 2014 at 08:43:21AM +0100, Jingoo Han wrote:
> On Wednesday, July 02, 2014 3:44 AM, Liviu Dudau wrote:
> > 
> > Several platforms use a rather generic version of parsing
> > the device tree to find the host bridge ranges. Move the common code
> > into the generic PCI code and use it to create a pci_host_bridge
> > structure that can be used by arch code.
> > 
> > Based on early attempts by Andrew Murray to unify the code.
> > Used powerpc and microblaze PCI code as starting point.
> > 
> > Signed-off-by: Liviu Dudau <Liviu.Dudau at arm.com>
> > Tested-by: Tanmay Inamdar <tinamdar at apm.com>
> > ---
> >  drivers/of/of_pci.c       | 135 ++++++++++++++++++++++++++++++++++++++++++++++
> >  drivers/pci/host-bridge.c |  18 +++++++
> >  include/linux/of_pci.h    |  10 ++++
> >  include/linux/pci.h       |   8 +++
> >  4 files changed, 171 insertions(+)
> > 
> > diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> > index 8481996..55d8320 100644
> > --- a/drivers/of/of_pci.c
> > +++ b/drivers/of/of_pci.c
> 
> [.....]
> 
> > +struct pci_host_bridge *
> > +of_create_pci_host_bridge(struct device *parent, struct pci_ops *ops, void *host_data)
> > +{
> > +	int err, domain, busno;
> > +	struct resource *bus_range;
> > +	struct pci_bus *root_bus;
> > +	struct pci_host_bridge *bridge;
> > +	resource_size_t io_base;
> > +	LIST_HEAD(res);
> > +
> > +	bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
> > +	if (!bus_range)
> > +		return ERR_PTR(-ENOMEM);
> > +
> > +	domain = of_alias_get_id(parent->of_node, "pci-domain");
> > +	if (domain == -ENODEV)
> > +		domain = atomic_inc_return(&domain_nr);
> > +
> > +	err = of_pci_parse_bus_range(parent->of_node, bus_range);
> > +	if (err) {
> > +		dev_info(parent, "No bus range for %s, using default [0-255]\n",
> > +			parent->of_node->full_name);
> > +		bus_range->start = 0;
> > +		bus_range->end = 255;
> > +		bus_range->flags = IORESOURCE_BUS;
> > +	}
> > +	busno = bus_range->start;
> > +	pci_add_resource(&res, bus_range);
> > +
> > +	/* now parse the rest of host bridge bus ranges */
> > +	err = pci_host_bridge_of_get_ranges(parent->of_node, &res, &io_base);
> > +	if (err)
> > +		goto err_create;
> > +
> > +	/* then create the root bus */
> > +	root_bus = pci_create_root_bus_in_domain(parent, domain, busno,
> > +						ops, host_data, &res);
> > +	if (IS_ERR(root_bus)) {
> > +		err = PTR_ERR(root_bus);
> > +		goto err_create;
> > +	}
> > +
> > +	bridge = to_pci_host_bridge(root_bus->bridge);
> > +	bridge->io_base = io_base;
> 
> Hi Liviu Dudau,
> 
> Would you fix the following warning?
> 
> drivers/of/of_pci.c: In function 'of_create_pci_host_bridge'
> drivers/of/of_pci.c:218:18: warning: 'of_base' may be used uninitialized in this function [-Wmaybe-uninitialized]
>   bridge->io_base = io_base;

Yes, I have a simple fix which is to set the initial value to zero when declaring the variable.

Best regards,
Liviu

> 
> Best regards,
> Jingoo Han
> 
> [.....]
> 
> 

-- 
====================
| I would like to |
| fix the world,  |
| but they're not |
| giving me the   |
 \ source code!  /
  ---------------
    ¯\_(ツ)_/¯