Re: [PATCH v6 12/30] PCI: Introduce pci_host_bridge_ops to support host specific operations

From: Yijing Wang
Date: Thu Mar 12 2015 - 09:15:12 EST


>> void pci_free_host_bridge(struct pci_host_bridge *host);
>> #endif /* DRIVERS_PCI_H */
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index c8e074d..59d9be3 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -1889,6 +1889,8 @@ static struct pci_bus *__pci_create_root_bus(
>>
>> bridge->bus = b;
>> b->bridge = get_device(&bridge->dev);
>> + if (bridge->ops && bridge->ops->set_root_bus_speed)
>> + bridge->ops->set_root_bus_speed(bridge);
>
> Before this patch, can you do this:
>
> - Rename the powerpc pcibios_root_bridge_prepare() to
> pcibios_set_root_bus_speed() and add a call to it here
>
> - Move the pcibios_root_bridge_prepare() call to pci_create_host_bridge()
>
> Then this patch will make a lot more sense because it will look like this,
> with the host bridge ops call right next to the matching pcibios call:
>
> + if (host->ops && host->ops->prepare) {
> + error = host->ops->prepare(host);
> + ...
> + }
> pcibios_root_bridge_prepare(...);
>
> + if (bridge->ops && bridge->ops->set_root_bus_speed)
> + bridge->ops->set_root_bus_speed(bridge);
> pcibios_set_root_bus_speed(...);

OK, will update.

>
>> error = pcibios_root_bridge_prepare(bridge);
>> if (error)
>> goto err_out;
>> @@ -1954,7 +1956,7 @@ struct pci_bus *pci_create_root_bus(struct device *parent, u32 db,
>> {
>> struct pci_host_bridge *host;
>>
>> - host = pci_create_host_bridge(parent, db, resources, sysdata);
>> + host = pci_create_host_bridge(parent, db, resources, sysdata, NULL);
>> if (!host)
>> return NULL;
>>
>> @@ -2051,10 +2053,13 @@ static struct pci_bus *__pci_scan_root_bus(
>> pci_bus_insert_busn_res(b, b->number, 255);
>> }
>>
>> - max = pci_scan_child_bus(b);
>> -
>> - if (!found)
>> - pci_bus_update_busn_res_end(b, max);
>> + if (host->ops && host->ops->scan_bus) {
>> + host->ops->scan_bus(host);
>> + } else {
>> + max = pci_scan_child_bus(b);
>> + if (!found)
>> + pci_bus_update_busn_res_end(b, max);
>> + }
>
> I think host->ops->scan_bus() should have the same prototype as
> pci_scan_child_bus(), and it should return max, and you should do the same
> busn update as when you call pci_scan_child_bus(). So the code would look
> like this:
>
> if (host->ops && host->ops->scan_bus)
> max = host->ops->scan_bus(b);
> else
> max = pci_scan_child_bus(b);
>
> if (!found)
> pci_bus_update_busn_res_end(b, max);
>

OK, I will try to change the of scan_bus(), and make it return the max bus number like pci_scan_child_bus().

>>
>> return b;
>> }
>> @@ -2064,7 +2069,7 @@ struct pci_bus *pci_scan_root_bus(struct device *parent, u32 db,
>> {
>> struct pci_host_bridge *host;
>>
>> - host = pci_create_host_bridge(parent, db, resources, sysdata);
>> + host = pci_create_host_bridge(parent, db, resources, sysdata, NULL);
>> if (!host)
>> return NULL;
>>
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index b621f5b..e9922b1 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -400,6 +400,13 @@ static inline int pci_channel_offline(struct pci_dev *pdev)
>> return (pdev->error_state != pci_channel_io_normal);
>> }
>>
>> +struct pci_host_bridge;
>> +struct pci_host_bridge_ops {
>> + void (*set_root_bus_speed)(struct pci_host_bridge *host);
>> + int (*prepare)(struct pci_host_bridge *host);
>> + void (*scan_bus)(struct pci_host_bridge *);
>
> Needs an argument name to match the style of the other ops.

Sorry, I missed it, will add it, thanks.


>
>> +};
>> +
>> struct pci_host_bridge {
>> u16 domain;
>> u16 busnum;
>> @@ -407,6 +414,7 @@ struct pci_host_bridge {
>> struct pci_bus *bus; /* root bus */
>> struct list_head windows; /* resource_entry */
>> struct list_head list;
>> + struct pci_host_bridge_ops *ops;
>> void (*release_fn)(struct pci_host_bridge *);
>> void *release_data;
>> };
>> --
>> 1.7.1
>>
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>
> .
>


--
Thanks!
Yijing

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