devlink: Improve the port attributes description

Current PF number description is vague, sometimes interpreted as
some PF index. VF number in the PCI specification starts at 1; however
in kernel, it starts at 0 for representor model.

Improve the description of devlink port attributes PF, VF and SF
numbers with these details.

Reviewed-by: Sridhar Samudrala <[e-mail]>
Reviewed-by: Shay Drory <[e-mail]>
Reviewed-by: Mark Bloch <[e-mail]>
Reviewed-by: Jiri Pirko <[e-mail]>
Signed-off-by: Parav Pandit <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

include/net/devlink.h

···
 /**
  * struct devlink_port_pci_pf_attrs - devlink port's PCI PF attributes
  * @controller: Associated controller number
- * @pf: Associated PCI PF number for this port.
+ * @pf: associated PCI function number for the devlink port instance
  * @external: when set, indicates if a port is for an external controller
  */
 struct devlink_port_pci_pf_attrs {
···
 /**
  * struct devlink_port_pci_vf_attrs - devlink port's PCI VF attributes
  * @controller: Associated controller number
- * @pf: Associated PCI PF number for this port.
- * @vf: Associated PCI VF for of the PCI PF for this port.
+ * @pf: associated PCI function number for the devlink port instance
+ * @vf: associated PCI VF number of a PF for the devlink port instance;
+ *	VF number starts from 0 for the first PCI virtual function
  * @external: when set, indicates if a port is for an external controller
  */
 struct devlink_port_pci_vf_attrs {
···
 /**
  * struct devlink_port_pci_sf_attrs - devlink port's PCI SF attributes
  * @controller: Associated controller number
- * @sf: Associated PCI SF for of the PCI PF for this port.
- * @pf: Associated PCI PF number for this port.
+ * @sf: associated SF number of a PF for the devlink port instance
+ * @pf: associated PCI function number for the devlink port instance
  * @external: when set, indicates if a port is for an external controller
  */
 struct devlink_port_pci_sf_attrs {

net/devlink/port.c

···
  *
  *	@devlink_port: devlink port
  *	@controller: associated controller number for the devlink port instance
- *	@pf: associated PF for the devlink port instance
+ *	@pf: associated PCI function number for the devlink port instance
  *	@external: indicates if the port is for an external controller
  */
 void devlink_port_attrs_pci_pf_set(struct devlink_port *devlink_port, u32 controller,
···
  *
  *	@devlink_port: devlink port
  *	@controller: associated controller number for the devlink port instance
- *	@pf: associated PF for the devlink port instance
- *	@vf: associated VF of a PF for the devlink port instance
+ *	@pf: associated PCI function number for the devlink port instance
+ *	@vf: associated PCI VF number of a PF for the devlink port instance;
+ *	     VF number starts from 0 for the first PCI virtual function
  *	@external: indicates if the port is for an external controller
  */
 void devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port, u32 controller,
···
  *
  *	@devlink_port: devlink port
  *	@controller: associated controller number for the devlink port instance
- *	@pf: associated PF for the devlink port instance
- *	@sf: associated SF of a PF for the devlink port instance
+ *	@pf: associated PCI function number for the devlink port instance
+ *	@sf: associated SF number of a PF for the devlink port instance
  *	@external: indicates if the port is for an external controller
  */
 void devlink_port_attrs_pci_sf_set(struct devlink_port *devlink_port, u32 controller,