The commit
53844673d555 ("iavf: kill 'legacy-rx' for good") removed
the legacy Rx path in the iavf driver. This change applies the same
rationale to the ice driver.
The legacy Rx path relied on manual skb allocation and header copying,
which has become increasingly inefficient and difficult to maintain.
With the stabilization of build_skb() and the growing adoption of
features like XDP, page_pool, and multi-buffer support, the legacy
approach is no longer viable.
Key drawbacks of the legacy path included:
- Higher memory pressure due to direct page allocations and splitting;
- Redundant memcpy() operations for packet headers;
- CPU overhead from eth_get_headlen() and Flow Dissector usage;
- Compatibility issues with XDP, which imposes strict headroom and
tailroom requirements.
The ice driver, like iavf, does not benefit from the minimal headroom
savings that legacy Rx once offered, as it already splits pages into
fixed halves. Removing this path simplifies the Rx logic, eliminates
unnecessary branches in the hotpath, and prepares the driver for
upcoming enhancements.
In addition to removing the legacy Rx path, this change also eliminates
the custom construct_skb() functions from both the standard and
zero-copy (ZC) Rx paths. These are replaced with the build_skb()
and standardized xdp_build_skb_from_zc() helpers, aligning the driver
with the modern XDP infrastructure and reducing code duplication.
This cleanup also reduces code complexity and improves maintainability
as we move toward a more unified and modern Rx model across drivers.
Co-developed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Michal Kubiak <michal.kubiak@intel.com>
Tested-by: Alexander Nowlin <alexander.nowlin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
ICE_FLAG_MOD_POWER_UNSUPPORTED,
ICE_FLAG_PHY_FW_LOAD_FAILED,
ICE_FLAG_ETHTOOL_CTXT, /* set when ethtool holds RTNL lock */
- ICE_FLAG_LEGACY_RX,
ICE_FLAG_VF_TRUE_PROMISC_ENA,
ICE_FLAG_MDD_AUTO_RESET_VF,
ICE_FLAG_VF_VLAN_PRUNING,
return tx_ring->count + max_fetch_desc;
}
-/**
- * ice_rx_offset - Return expected offset into page to access data
- * @rx_ring: Ring we are requesting offset of
- *
- * Returns the offset value for ring into the data buffer.
- */
-static unsigned int ice_rx_offset(struct ice_rx_ring *rx_ring)
-{
- if (ice_ring_uses_build_skb(rx_ring))
- return ICE_SKB_PAD;
- return 0;
-}
-
/**
* ice_setup_rx_ctx - Configure a receive ring context
* @ring: The Rx ring to configure
if (vsi->type == ICE_VSI_VF)
return 0;
- /* configure Rx buffer alignment */
- if (!vsi->netdev || test_bit(ICE_FLAG_LEGACY_RX, vsi->back->flags))
- ice_clear_ring_build_skb_ena(ring);
- else
- ice_set_ring_build_skb_ena(ring);
-
- ring->rx_offset = ice_rx_offset(ring);
+ ring->rx_offset = ICE_SKB_PAD;
/* init queue specific tail register */
ring->tail = hw->hw_addr + QRX_TAIL(pf_q);
*/
static void ice_vsi_cfg_frame_size(struct ice_vsi *vsi, struct ice_rx_ring *ring)
{
- if (!vsi->netdev || test_bit(ICE_FLAG_LEGACY_RX, vsi->back->flags)) {
+ if (!vsi->netdev) {
ring->max_frame = ICE_MAX_FRAME_LEGACY_RX;
ring->rx_buf_len = ICE_RXBUF_1664;
#if (PAGE_SIZE < 8192)
ICE_FLAG_VF_TRUE_PROMISC_ENA),
ICE_PRIV_FLAG("mdd-auto-reset-vf", ICE_FLAG_MDD_AUTO_RESET_VF),
ICE_PRIV_FLAG("vf-vlan-pruning", ICE_FLAG_VF_VLAN_PRUNING),
- ICE_PRIV_FLAG("legacy-rx", ICE_FLAG_LEGACY_RX),
};
#define ICE_PRIV_FLAG_ARRAY_SIZE ARRAY_SIZE(ice_gstrings_priv_flags)
ice_nway_reset(netdev);
}
}
- if (test_bit(ICE_FLAG_LEGACY_RX, change_flags)) {
- /* down and up VSI so that changes of Rx cfg are reflected. */
- ice_down_up(vsi);
- }
/* don't allow modification of this flag when a single VF is in
* promiscuous mode because it's not supported
*/
*/
static int ice_max_xdp_frame_size(struct ice_vsi *vsi)
{
- if (test_bit(ICE_FLAG_LEGACY_RX, vsi->back->flags))
- return ICE_RXBUF_1664;
- else
- return ICE_RXBUF_3072;
+ return ICE_RXBUF_3072;
}
/**
frame_size - ICE_ETH_PKT_HDR_PAD);
return -EINVAL;
}
- } else if (test_bit(ICE_FLAG_LEGACY_RX, pf->flags)) {
- if (new_mtu + ICE_ETH_PKT_HDR_PAD > ICE_MAX_FRAME_LEGACY_RX) {
- netdev_err(netdev, "Too big MTU for legacy-rx; Max is %d\n",
- ICE_MAX_FRAME_LEGACY_RX - ICE_ETH_PKT_HDR_PAD);
- return -EINVAL;
- }
}
/* if a reset is in progress, wait for some time for it to complete */
return skb;
}
-/**
- * ice_construct_skb - Allocate skb and populate it
- * @rx_ring: Rx descriptor ring to transact packets on
- * @xdp: xdp_buff pointing to the data
- *
- * This function allocates an skb. It then populates it with the page
- * data from the current receive descriptor, taking care to set up the
- * skb correctly.
- */
-static struct sk_buff *
-ice_construct_skb(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp)
-{
- unsigned int size = xdp->data_end - xdp->data;
- struct skb_shared_info *sinfo = NULL;
- struct ice_rx_buf *rx_buf;
- unsigned int nr_frags = 0;
- unsigned int headlen;
- struct sk_buff *skb;
-
- /* prefetch first cache line of first page */
- net_prefetch(xdp->data);
-
- if (unlikely(xdp_buff_has_frags(xdp))) {
- sinfo = xdp_get_shared_info_from_buff(xdp);
- nr_frags = sinfo->nr_frags;
- }
-
- /* allocate a skb to store the frags */
- skb = napi_alloc_skb(&rx_ring->q_vector->napi, ICE_RX_HDR_SIZE);
- if (unlikely(!skb))
- return NULL;
-
- rx_buf = &rx_ring->rx_buf[rx_ring->first_desc];
- skb_record_rx_queue(skb, rx_ring->q_index);
- /* Determine available headroom for copy */
- headlen = size;
- if (headlen > ICE_RX_HDR_SIZE)
- headlen = eth_get_headlen(skb->dev, xdp->data, ICE_RX_HDR_SIZE);
-
- /* align pull length to size of long to optimize memcpy performance */
- memcpy(__skb_put(skb, headlen), xdp->data, ALIGN(headlen,
- sizeof(long)));
-
- /* if we exhaust the linear part then add what is left as a frag */
- size -= headlen;
- if (size) {
- /* besides adding here a partial frag, we are going to add
- * frags from xdp_buff, make sure there is enough space for
- * them
- */
- if (unlikely(nr_frags >= MAX_SKB_FRAGS - 1)) {
- dev_kfree_skb(skb);
- return NULL;
- }
- skb_add_rx_frag(skb, 0, rx_buf->page,
- rx_buf->page_offset + headlen, size,
- xdp->frame_sz);
- } else {
- /* buffer is unused, restore biased page count in Rx buffer;
- * data was copied onto skb's linear part so there's no
- * need for adjusting page offset and we can reuse this buffer
- * as-is
- */
- rx_buf->pagecnt_bias++;
- }
-
- if (unlikely(xdp_buff_has_frags(xdp))) {
- struct skb_shared_info *skinfo = skb_shinfo(skb);
-
- memcpy(&skinfo->frags[skinfo->nr_frags], &sinfo->frags[0],
- sizeof(skb_frag_t) * nr_frags);
-
- xdp_update_skb_frags_info(skb, skinfo->nr_frags + nr_frags,
- sinfo->xdp_frags_size,
- nr_frags * xdp->frame_sz,
- xdp_buff_get_skb_flags(xdp));
- }
-
- return skb;
-}
-
/**
* ice_put_rx_buf - Clean up used buffer and either recycle or free
* @rx_ring: Rx descriptor ring to transact packets on
continue;
construct_skb:
- if (likely(ice_ring_uses_build_skb(rx_ring)))
- skb = ice_build_skb(rx_ring, xdp);
- else
- skb = ice_construct_skb(rx_ring, xdp);
+ skb = ice_build_skb(rx_ring, xdp);
/* exit if we failed to retrieve a buffer */
if (!skb) {
rx_ring->ring_stats->rx_stats.alloc_buf_failed++;
dma_addr_t dma; /* physical address of ring */
u8 dcb_tc; /* Traffic class of ring */
u8 ptp_rx;
-#define ICE_RX_FLAGS_RING_BUILD_SKB BIT(1)
#define ICE_RX_FLAGS_CRC_STRIP_DIS BIT(2)
#define ICE_RX_FLAGS_MULTIDEV BIT(3)
#define ICE_RX_FLAGS_RING_GCS BIT(4)
u16 quanta_prof_id;
} ____cacheline_internodealigned_in_smp;
-static inline bool ice_ring_uses_build_skb(struct ice_rx_ring *ring)
-{
- return !!(ring->flags & ICE_RX_FLAGS_RING_BUILD_SKB);
-}
-
-static inline void ice_set_ring_build_skb_ena(struct ice_rx_ring *ring)
-{
- ring->flags |= ICE_RX_FLAGS_RING_BUILD_SKB;
-}
-
-static inline void ice_clear_ring_build_skb_ena(struct ice_rx_ring *ring)
-{
- ring->flags &= ~ICE_RX_FLAGS_RING_BUILD_SKB;
-}
-
static inline bool ice_ring_ch_enabled(struct ice_tx_ring *ring)
{
return !!ring->ch;
return __ice_alloc_rx_bufs_zc(rx_ring, xsk_pool, leftover);
}
-/**
- * ice_construct_skb_zc - Create an sk_buff from zero-copy buffer
- * @rx_ring: Rx ring
- * @xdp: Pointer to XDP buffer
- *
- * This function allocates a new skb from a zero-copy Rx buffer.
- *
- * Returns the skb on success, NULL on failure.
- */
-static struct sk_buff *
-ice_construct_skb_zc(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp)
-{
- unsigned int totalsize = xdp->data_end - xdp->data_meta;
- unsigned int metasize = xdp->data - xdp->data_meta;
- struct skb_shared_info *sinfo = NULL;
- struct sk_buff *skb;
- u32 nr_frags = 0;
-
- if (unlikely(xdp_buff_has_frags(xdp))) {
- sinfo = xdp_get_shared_info_from_buff(xdp);
- nr_frags = sinfo->nr_frags;
- }
- net_prefetch(xdp->data_meta);
-
- skb = napi_alloc_skb(&rx_ring->q_vector->napi, totalsize);
- if (unlikely(!skb))
- return NULL;
-
- memcpy(__skb_put(skb, totalsize), xdp->data_meta,
- ALIGN(totalsize, sizeof(long)));
-
- if (metasize) {
- skb_metadata_set(skb, metasize);
- __skb_pull(skb, metasize);
- }
-
- if (likely(!xdp_buff_has_frags(xdp)))
- goto out;
-
- for (int i = 0; i < nr_frags; i++) {
- struct skb_shared_info *skinfo = skb_shinfo(skb);
- skb_frag_t *frag = &sinfo->frags[i];
- struct page *page;
- void *addr;
-
- page = dev_alloc_page();
- if (!page) {
- dev_kfree_skb(skb);
- return NULL;
- }
- addr = page_to_virt(page);
-
- memcpy(addr, skb_frag_page(frag), skb_frag_size(frag));
-
- __skb_fill_page_desc_noacc(skinfo, skinfo->nr_frags++,
- addr, 0, skb_frag_size(frag));
- }
-
-out:
- xsk_buff_free(xdp);
- return skb;
-}
-
/**
* ice_clean_xdp_irq_zc - produce AF_XDP descriptors to CQ
* @xdp_ring: XDP Tx ring
construct_skb:
/* XDP_PASS path */
- skb = ice_construct_skb_zc(rx_ring, first);
+ skb = xdp_build_skb_from_zc(first);
if (!skb) {
+ xsk_buff_free(first);
rx_ring->ring_stats->rx_stats.alloc_buf_failed++;
break;
}
first = NULL;
rx_ring->first_desc = ntc;
-
- if (eth_skb_pad(skb)) {
- skb = NULL;
- continue;
- }
-
total_rx_bytes += skb->len;
total_rx_packets++;
projects / thirdparty / kernel / linux.git / commitdiff
