Hi Thomas,
Thanks for reviewing this proposal.
> > Signed-off-by: Cristian Dumitrescu <cristian.dumitre...@intel.com>
> > Acked-by: Keith Wiles <keith.wi...@intel.com>
> > Acked-by: Jerin Jacob <jerin.ja...@caviumnetworks.com>
> > Acked-by: Hemant Agrawal <hemant.agra...@nxp.com>
> [...]
> > +enum rte_eth_capability {
> > + RTE_ETH_CAPABILITY_FLOW = 0, /**< Flow */
> > + RTE_ETH_CAPABILITY_TM, /**< Traffic Manager */
> > + RTE_ETH_CAPABILITY_MAX
> > +};
> [...]
> > /**
> > + * Take capability operations on an Ethernet device.
> > + *
> > + * @param port_id
> > + * The port identifier of the Ethernet device.
> > + * @param cap
> > + * The capability of the Ethernet device
> > + * @param arg
> > + * A pointer to arguments defined specifically for the operation.
> > + * @return
> > + * - (0) if successful.
> > + * - (-ENOTSUP) if hardware doesn't support.
> > + * - (-ENODEV) if *port_id* invalid.
> > + */
> > +int rte_eth_dev_capability_ops_get(uint8_t port_id,
> > + enum rte_eth_capability cap, void *arg);
>
> What is the benefit of getting different kind of capabilities with
> the same function?
> enum + void* = ioctl
> A self-explanatory API should have a dedicated function for each kind
> of features with different argument types.
The advantage is providing a standard interface to query the capabilities of
the device rather than having each capability provide its own mechanism in a
slightly different way.
IMO this mechanism is of great help to guide the developers of future ethdev
features on the clean path to add new features in a modular way, extending the
ethdev functionality while doing so in a separate name space and file (that's
why I tend to call this a plugin-like mechanism), as opposed to the current
monolithic approach for ethdev, where we have 100+ API functions in a single
name space and that are split into functional groups just by blank lines in the
header file. It is simply the generalization of the mechanism introduced by
rte_flow in release 17.02 (so all the credit should go to Adrien and not me).
IMO, having a standard function as above it cleaner than having a separate and
slightly different function per feature. People can quickly see the set of
standard ethdev capabilities and which ones are supported by a specific device.
Between A) and B) below, I definitely prefer A):
A) status = rte_eth_dev_capability_ops_get(port_id, RTE_ETH_CABABILITY_TM,
&tm_ops);
B) status = rte_eth_dev_tm_ops_get(port_id, &tm_ops);
Regards,
Cristian
