Re: [PATCH v11 15/16] PCI/PME: Add pcie_walk_rcec() to RCEC PME handling

[Kelley, Sean V]

Hi Sathya,

> On Nov 17, 2020, at 10:03 PM, Kuppuswamy, Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote:
> 
> 
> 
> On 11/17/20 11:19 AM, Sean V Kelley wrote:
>> Root Complex Event Collectors (RCEC) appear as peers of Root Ports and also
>> have the PME capability. As with AER, there is a need to be able to walk
>> the RCiEPs associated with their RCEC for purposes of acting upon them with
>> callbacks.
>> Add RCEC support through the use of pcie_walk_rcec() to the current PME
>> service driver and attach the PME service driver to the RCEC device.
>> Co-developed-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
>> Link: https://lore.kernel.org/r/20201002184735.1229220-14-seanvk.dev@xxxxxxxxxxxxxxxx
>> Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
>> Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
>> Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
>> ---
>>  drivers/pci/pcie/pme.c          | 15 +++++++++++----
>>  drivers/pci/pcie/portdrv_core.c |  9 +++------
>>  2 files changed, 14 insertions(+), 10 deletions(-)
>> diff --git a/drivers/pci/pcie/pme.c b/drivers/pci/pcie/pme.c
>> index 6a32970bb731..87799166c96a 100644
>> --- a/drivers/pci/pcie/pme.c
>> +++ b/drivers/pci/pcie/pme.c
>> @@ -310,7 +310,10 @@ static int pcie_pme_can_wakeup(struct pci_dev *dev, void *ign)
>>  static void pcie_pme_mark_devices(struct pci_dev *port)
>>  {
>>  	pcie_pme_can_wakeup(port, NULL);
>> -	if (port->subordinate)
>> +
>> +	if (pci_pcie_type(port) == PCI_EXP_TYPE_RC_EC)
>> +		pcie_walk_rcec(port, pcie_pme_can_wakeup, NULL);
>> +	else if (port->subordinate)
>>  		pci_walk_bus(port->subordinate, pcie_pme_can_wakeup, NULL);
>>  }
>>  @@ -320,10 +323,15 @@ static void pcie_pme_mark_devices(struct pci_dev *port)
>>   */
>>  static int pcie_pme_probe(struct pcie_device *srv)
>>  {
>> -	struct pci_dev *port;
>> +	struct pci_dev *port = srv->port;
>>  	struct pcie_pme_service_data *data;
>>  	int ret;
>>  +	/* Limit to Root Ports or Root Complex Event Collectors */
>> +	if ((pci_pcie_type(port) != PCI_EXP_TYPE_RC_EC) &&
>> +	    (pci_pcie_type(port) != PCI_EXP_TYPE_ROOT_PORT))
> may be you can save the value pci_pcie_type(port)?

Good suggestion. Will add.

Thanks,

Sean

>> +		return -ENODEV;
>> +
>>  	data = kzalloc(sizeof(*data), GFP_KERNEL);
>>  	if (!data)
>>  		return -ENOMEM;
>> @@ -333,7 +341,6 @@ static int pcie_pme_probe(struct pcie_device *srv)
>>  	data->srv = srv;
>>  	set_service_data(srv, data);
>>  -	port = srv->port;
>>  	pcie_pme_interrupt_enable(port, false);
>>  	pcie_clear_root_pme_status(port);
>>  @@ -445,7 +452,7 @@ static void pcie_pme_remove(struct pcie_device *srv)
>>    static struct pcie_port_service_driver pcie_pme_driver = {
>>  	.name		= "pcie_pme",
>> -	.port_type	= PCI_EXP_TYPE_ROOT_PORT,
>> +	.port_type	= PCIE_ANY_PORT,
>>  	.service	= PCIE_PORT_SERVICE_PME,
>>    	.probe		= pcie_pme_probe,
>> diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
>> index 50a9522ab07d..e1fed6649c41 100644
>> --- a/drivers/pci/pcie/portdrv_core.c
>> +++ b/drivers/pci/pcie/portdrv_core.c
>> @@ -233,12 +233,9 @@ static int get_port_device_capability(struct pci_dev *dev)
>>  	}
>>  #endif
>>  -	/*
>> -	 * Root ports are capable of generating PME too.  Root Complex
>> -	 * Event Collectors can also generate PMEs, but we don't handle
>> -	 * those yet.
>> -	 */
>> -	if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
>> +	/* Root Ports and Root Complex Event Collectors may generate PMEs */
>> +	if ((pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
>> +	     pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC) &&
>>  	    (pcie_ports_native || host->native_pme)) {
>>  		services |= PCIE_PORT_SERVICE_PME;
>>  
> 
> -- 
> Sathyanarayanan Kuppuswamy
> Linux Kernel Developer