On Tue, Dec 09, 2025 at 11:26:40AM +0000, Ciara Loftus wrote: > The code for determining which Tx path to select during initialisation > has become complicated in many intel drivers due to the amount of > different paths and features available within each path. This commit > aims to simplify and genericize the path selection logic. > > The following information about each Tx burst function is stored and > used by the new common function to select the appropriate Tx path: > - Tx Offloads > - SIMD bitwidth > > The implementation is based off the Rx path selection infrastructure > introduced in a previous commit. > > Signed-off-by: Ciara Loftus <[email protected]>
Generally looks good, a few minor suggestions inline below. Acked-by: Bruce Richardson <[email protected]> > --- > drivers/net/intel/common/tx.h | 71 +++++++++++++++++++++++++++++++++++ > 1 file changed, 71 insertions(+) > > diff --git a/drivers/net/intel/common/tx.h b/drivers/net/intel/common/tx.h > index 5af64a4cfe..c6c1904ba3 100644 > --- a/drivers/net/intel/common/tx.h > +++ b/drivers/net/intel/common/tx.h > @@ -8,6 +8,7 @@ > #include <stdint.h> > #include <rte_mbuf.h> > #include <rte_ethdev.h> > +#include <rte_vect.h> > > /* forward declaration of the common intel (ci) queue structure */ > struct ci_tx_queue; > @@ -117,6 +118,17 @@ struct ci_tx_queue { > }; > }; > > +struct ci_tx_path_features { > + uint32_t tx_offloads; > + enum rte_vect_max_simd simd_width; > +}; > + > +struct ci_tx_path_info { > + eth_tx_burst_t pkt_burst; > + const char *info; > + struct ci_tx_path_features features; > +}; > + > static __rte_always_inline void > ci_tx_backlog_entry(struct ci_tx_entry *txep, struct rte_mbuf **tx_pkts, > uint16_t nb_pkts) > { > @@ -262,4 +274,63 @@ ci_txq_release_all_mbufs(struct ci_tx_queue *txq, bool > use_ctx) > memset(txq->sw_ring_vec, 0, sizeof(txq->sw_ring_vec[0]) * nb_desc); > } > > +/** > + * Select the best matching Tx path based on features > + * > + * @param req_features > + * The requested features for the Tx path > + * @param infos > + * Array of information about the available Tx paths > + * @param num_paths > + * Number of available paths in the infos array > + * @param default_path > + * Index of the default path to use if no suitable path is found > + * > + * @return > + * The packet burst function index that best matches the requested > features, > + * or default_path if no suitable path is found > + */ > +static inline int > +ci_tx_path_select(struct ci_tx_path_features req_features, Is there a reason we are passing this by value, rather than as a const pointer? > + const struct ci_tx_path_info *infos, > + int num_paths, Minor nit: general the size of arrays should be of type "size_t", which matches the value got from sizeof, and hence RTE_DIM. Since we don't need to support negative sized arrays, an unsigned type is better generally. > + int default_path) > +{ > + int i, idx = default_path; > + const struct ci_tx_path_features *chosen_path_features = NULL; > + > + for (i = 0; i < num_paths; i++) { If num_paths is size_t, "i" should be an unsigned value to match. I'd also to prefer that "i" also be defined inside the "for" statement, since its unneeded outside of it. > + const struct ci_tx_path_features *path_features = > &infos[i].features; > + > + /* Ensure the path supports the requested TX offloads. */ > + if ((path_features->tx_offloads & req_features.tx_offloads) != > + req_features.tx_offloads) > + continue; > + > + /* Ensure the path's SIMD width is compatible with the > requested width. */ > + if (path_features->simd_width > req_features.simd_width) > + continue; > + > + /* Do not select the path if it is less suitable than the > chosen path. */ > + if (chosen_path_features != NULL) { > + /* Do not select paths with lower SIMD width than the > chosen path. */ > + if (path_features->simd_width < > chosen_path_features->simd_width) > + continue; > + /* Do not select paths with more offloads enabled than > the chosen path if > + * the SIMD widths are the same. > + */ > + if (path_features->simd_width == > chosen_path_features->simd_width && > + > rte_popcount32(path_features->tx_offloads) > > + > rte_popcount32(chosen_path_features->tx_offloads)) > + continue; > + } > + > + /* Finally, select the path since it has met all the > requirements. */ > + idx = i; > + chosen_path_features = &infos[idx].features; > + } > + > + return idx; > +} > + > #endif /* _COMMON_INTEL_TX_H_ */ > -- > 2.43.0 >
