Re: [PATCH v3 3/6] PCI: Add generic function to probe PCI host controllers

[Cyrille Pitchen]

Hi Lorenzo,

Le 16/01/2018 Ã 16:25, Lorenzo Pieralisi a ÃcritÂ:
> On Wed, Jan 10, 2018 at 11:47:32PM +0100, Cyrille Pitchen wrote:
>> This patchs moves generic source code from
>> drivers/pci/host/pci-host-common.c into drivers/pci/probe.c.
>>
>> Indeed the extracted lines of code were duplicated by many host
>> controller drivers. Regrouping them into a generic function gives a
>> change to properly share this code without introducing a useless
>> dependency to PCI_HOST_COMMON, which selects PCI_ECAM when not needed by
>> most host controller drivers.
>>
>> We also add a missing call of pci_free_resource_list() from
>> pci_host_common_probe() when probing fails, as done inside gen_pci_init()
> I have to ask you to split this change into another patch.
> 
> First add the missing pci_free_resource_list() then add this patch.
> 
> Do you have time to respin quickly ? I would like to merge this
> series for v4.16.
>

Sorry, I've been a little bit busy. I've just done it and submit v4.
patch 3 from v3 split into patches 3 and 4 in v4.

Best regards,

Cyrille

 
> Thanks,
> Lorenzo
> 
>> when this later function fails.
>>
>> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@xxxxxxxxxxxxxxxxxx>
>> ---
>>  drivers/pci/host/pci-host-common.c | 25 +++----------------------
>>  drivers/pci/probe.c                | 33 +++++++++++++++++++++++++++++++++
>>  include/linux/pci.h                |  1 +
>>  3 files changed, 37 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/pci/host/pci-host-common.c b/drivers/pci/host/pci-host-common.c
>> index a613ea310e76..df25b4a4edaf 100644
>> --- a/drivers/pci/host/pci-host-common.c
>> +++ b/drivers/pci/host/pci-host-common.c
>> @@ -72,7 +72,6 @@ int pci_host_common_probe(struct platform_device *pdev,
>>  	const char *type;
>>  	struct device *dev = &pdev->dev;
>>  	struct device_node *np = dev->of_node;
>> -	struct pci_bus *bus, *child;
>>  	struct pci_host_bridge *bridge;
>>  	struct pci_config_window *cfg;
>>  	struct list_head resources;
>> @@ -107,29 +106,11 @@ int pci_host_common_probe(struct platform_device *pdev,
>>  	bridge->map_irq = of_irq_parse_and_map_pci;
>>  	bridge->swizzle_irq = pci_common_swizzle;
>>  
>> -	ret = pci_scan_root_bus_bridge(bridge);
>> -	if (ret < 0) {
>> -		dev_err(dev, "Scanning root bridge failed");
>> +	ret = pci_host_probe(bridge);
>> +	if (ret) {
>> +		pci_free_resource_list(&resources);
>>  		return ret;
>>  	}
>>  
>> -	bus = bridge->bus;
>> -
>> -	/*
>> -	 * We insert PCI resources into the iomem_resource and
>> -	 * ioport_resource trees in either pci_bus_claim_resources()
>> -	 * or pci_bus_assign_resources().
>> -	 */
>> -	if (pci_has_flag(PCI_PROBE_ONLY)) {
>> -		pci_bus_claim_resources(bus);
>> -	} else {
>> -		pci_bus_size_bridges(bus);
>> -		pci_bus_assign_resources(bus);
>> -
>> -		list_for_each_entry(child, &bus->children, node)
>> -			pcie_bus_configure_settings(child);
>> -	}
>> -
>> -	pci_bus_add_devices(bus);
>>  	return 0;
>>  }
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index 1360db508035..178328d06a32 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -2685,6 +2685,39 @@ struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
>>  }
>>  EXPORT_SYMBOL_GPL(pci_create_root_bus);
>>  
>> +int pci_host_probe(struct pci_host_bridge *bridge)
>> +{
>> +	struct pci_bus *bus, *child;
>> +	int ret;
>> +
>> +	ret = pci_scan_root_bus_bridge(bridge);
>> +	if (ret < 0) {
>> +		dev_err(bridge->dev.parent, "Scanning root bridge failed");
>> +		return ret;
>> +	}
>> +
>> +	bus = bridge->bus;
>> +
>> +	/*
>> +	 * We insert PCI resources into the iomem_resource and
>> +	 * ioport_resource trees in either pci_bus_claim_resources()
>> +	 * or pci_bus_assign_resources().
>> +	 */
>> +	if (pci_has_flag(PCI_PROBE_ONLY)) {
>> +		pci_bus_claim_resources(bus);
>> +	} else {
>> +		pci_bus_size_bridges(bus);
>> +		pci_bus_assign_resources(bus);
>> +
>> +		list_for_each_entry(child, &bus->children, node)
>> +			pcie_bus_configure_settings(child);
>> +	}
>> +
>> +	pci_bus_add_devices(bus);
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(pci_host_probe);
>> +
>>  int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max)
>>  {
>>  	struct resource *res = &b->busn_res;
>> diff --git a/include/linux/pci.h b/include/linux/pci.h
>> index a1b0672fd38a..0ca261fda900 100644
>> --- a/include/linux/pci.h
>> +++ b/include/linux/pci.h
>> @@ -879,6 +879,7 @@ struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata);
>>  struct pci_bus *pci_create_root_bus(struct device *parent, int bus,
>>  				    struct pci_ops *ops, void *sysdata,
>>  				    struct list_head *resources);
>> +int pci_host_probe(struct pci_host_bridge *bridge);
>>  int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int busmax);
>>  int pci_bus_update_busn_res_end(struct pci_bus *b, int busmax);
>>  void pci_bus_release_busn_res(struct pci_bus *b);
>> -- 
>> 2.11.0
>>
> 


-- 
Cyrille Pitchen, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com