Re: [PATCH iwl-next v2] ice: Extend auxbus device naming

[Jiri Pirko <jiri@resnulli.us>]

Tue, Apr 23, 2024 at 01:56:55PM CEST, sergey.temerkhanov@intel.com wrote:
>
>
>> -----Original Message-----
>> From: Jiri Pirko <jiri@resnulli.us>
>> Sent: Tuesday, April 23, 2024 1:36 PM
>> To: Temerkhanov, Sergey <sergey.temerkhanov@intel.com>
>> Cc: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; Kitszel,
>> Przemyslaw <przemyslaw.kitszel@intel.com>
>> Subject: Re: [PATCH iwl-next v2] ice: Extend auxbus device naming
>> 
>> Tue, Apr 23, 2024 at 11:14:59AM CEST, sergey.temerkhanov@intel.com
>> wrote:
>> >Include segment/domain number in the device name to distinguish
>> between
>> >PCI devices located on different root complexes in multi-segment
>> >configurations. Naming is changed from ptp_<bus>_<slot>_clk<clock>  to
>> >ptp_<domain>_<bus>_<slot>_clk<clock>
>> 
>> I don't understand why you need to encode pci properties of a parent device
>> into the auxiliary bus name. Could you please explain the motivation? Why
>> you need a bus instance per PF?
>> 
>> The rest of the auxbus registrators don't do this. Could you please align? Just
>> have one bus for ice driver and that's it.
>
>This patch adds support for multi-segment PCIe configurations.
>An auxdev is created for each adapter, which has a clock, in the system. There can be

You are trying to change auxiliary bus name.


>more than one adapter present, so there exists a possibility of device naming conflict.
>To avoid it, auxdevs are named according to the PCI geographical addresses of the adapters.

Why? It's the auxdev, the name should not contain anything related to
PCI, no reason for it. I asked for motivation, you didn't provide any.

Again, could you please avoid creating auxiliary bus per-PF and just
have one auxiliary but per-ice-driver?


>
>Some systems may have adapters connected to different RCs which represent separate
>PCI segments/domains. In such cases, BDF numbers  for these adapters can match, triggering
>the naming conflict again. To avoid that, auxdev names are further extended to include the
>segment/domain number.
>  
>> 
>> 
>> >
>> >v1->v2
>> >Rebase on top of the latest changes
>> >
>> >Signed-off-by: Sergey Temerkhanov <sergey.temerkhanov@intel.com>
>> >Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
>> >---
>> > drivers/net/ethernet/intel/ice/ice_ptp.c | 18 ++++++++++++------
>> > 1 file changed, 12 insertions(+), 6 deletions(-)
>> >
>> >diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c
>> >b/drivers/net/ethernet/intel/ice/ice_ptp.c
>> >index 402436b72322..744b102f7636 100644
>> >--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
>> >+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
>> >@@ -2993,8 +2993,9 @@ ice_ptp_auxbus_create_id_table(struct ice_pf
>> *pf,
>> >const char *name)  static int ice_ptp_register_auxbus_driver(struct
>> >ice_pf *pf)  {
>> > 	struct auxiliary_driver *aux_driver;
>> >+	struct pci_dev *pdev = pf->pdev;
>> > 	struct ice_ptp *ptp;
>> >-	char busdev[8] = {};
>> >+	char busdev[16] = {};
>> > 	struct device *dev;
>> > 	char *name;
>> > 	int err;
>> >@@ -3005,8 +3006,10 @@ static int ice_ptp_register_auxbus_driver(struct
>> ice_pf *pf)
>> > 	INIT_LIST_HEAD(&ptp->ports_owner.ports);
>> > 	mutex_init(&ptp->ports_owner.lock);
>> > 	if (ice_is_e810(&pf->hw))
>> >-		sprintf(busdev, "%u_%u_", pf->pdev->bus->number,
>> >-			PCI_SLOT(pf->pdev->devfn));
>> >+		snprintf(busdev, sizeof(busdev), "%u_%u_%u_",
>> >+			 pci_domain_nr(pdev->bus),
>> >+			 pdev->bus->number,
>> >+			 PCI_SLOT(pdev->devfn));
>> > 	name = devm_kasprintf(dev, GFP_KERNEL, "ptp_%sclk%u", busdev,
>> > 			      ice_get_ptp_src_clock_index(&pf->hw));
>> > 	if (!name)
>> >@@ -3210,8 +3213,9 @@ static void ice_ptp_release_auxbus_device(struct
>> >device *dev)  static int ice_ptp_create_auxbus_device(struct ice_pf
>> >*pf)  {
>> > 	struct auxiliary_device *aux_dev;
>> >+	struct pci_dev *pdev = pf->pdev;
>> > 	struct ice_ptp *ptp;
>> >-	char busdev[8] = {};
>> >+	char busdev[16] = {};
>> > 	struct device *dev;
>> > 	char *name;
>> > 	int err;
>> >@@ -3224,8 +3228,10 @@ static int ice_ptp_create_auxbus_device(struct
>> ice_pf *pf)
>> > 	aux_dev = &ptp->port.aux_dev;
>> >
>> > 	if (ice_is_e810(&pf->hw))
>> >-		sprintf(busdev, "%u_%u_", pf->pdev->bus->number,
>> >-			PCI_SLOT(pf->pdev->devfn));
>> >+		snprintf(busdev, sizeof(busdev), "%u_%u_%u_",
>> >+			 pci_domain_nr(pdev->bus),
>> >+			 pdev->bus->number,
>> >+			 PCI_SLOT(pdev->devfn));
>> >
>> > 	name = devm_kasprintf(dev, GFP_KERNEL, "ptp_%sclk%u", busdev,
>> > 			      ice_get_ptp_src_clock_index(&pf->hw));
>> >--
>> >2.35.3
>> >
>> >