[PATCH bpf-next 09/13] ice: use xdp->frame_sz instead of recalculating truesize

Maciej Fijalkowski
2023-01-31T20:46:57Z

SKB path calculates truesize on three different functions, which could
be avoided as xdp_buff carries the already calculated truesize under
xdp_buff::frame_sz. If ice_add_rx_frag() is adjusted to take the
xdp_buff as an input just like functions responsible for creating
sk_buff initially, codebase could be simplified by removing these
redundant recalculations and rely on xdp_buff::frame_sz instead.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
---
drivers/net/ethernet/intel/ice/ice_txrx.c | 33 +++++++----------------
1 file changed, 9 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c
index 3a8639608f0b..dd4d7f5ba6bd 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.c
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.c
@@ -840,6 +840,7 @@ ice_can_reuse_rx_page(struct ice_rx_buf *rx_buf)
/**
* ice_add_rx_frag - Add contents of Rx buffer to sk_buff as a frag
* @rx_ring: Rx descriptor ring to transact packets on
+ * @xdp: XDP buffer
* @rx_buf: buffer containing page to add
* @skb: sk_buff to place the data into
* @size: packet length from rx_desc
@@ -849,19 +850,14 @@ ice_can_reuse_rx_page(struct ice_rx_buf *rx_buf)
* The function will then update the page offset.
*/
static void
-ice_add_rx_frag(struct ice_rx_ring *rx_ring, struct ice_rx_buf *rx_buf,
- struct sk_buff *skb, unsigned int size)
+ice_add_rx_frag(struct ice_rx_ring *rx_ring, struct xdp_buff *xdp,
+ struct ice_rx_buf *rx_buf, struct sk_buff *skb,
+ unsigned int size)
{
-#if (PAGE_SIZE >= 8192)
- unsigned int truesize = SKB_DATA_ALIGN(size + rx_ring->rx_offset);
-#else
- unsigned int truesize = ice_rx_pg_size(rx_ring) / 2;
-#endif
-
if (!size)
return;
skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_buf->page,
- rx_buf->page_offset, size, truesize);
+ rx_buf->page_offset, size, xdp->frame_sz);
}

/**
@@ -943,13 +939,6 @@ ice_build_skb(struct ice_rx_ring *rx_ring, struct ice_rx_buf *rx_buf,
struct xdp_buff *xdp)
{
u8 metasize = xdp->data - xdp->data_meta;
-#if (PAGE_SIZE < 8192)
- unsigned int truesize = ice_rx_pg_size(rx_ring) / 2;
-#else
- unsigned int truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) +
- SKB_DATA_ALIGN(xdp->data_end -
- xdp->data_hard_start);
-#endif
struct sk_buff *skb;

/* Prefetch first cache line of first page. If xdp->data_meta
@@ -959,7 +948,7 @@ ice_build_skb(struct ice_rx_ring *rx_ring, struct ice_rx_buf *rx_buf,
*/
net_prefetch(xdp->data_meta);
/* build an skb around the page buffer */
- skb = napi_build_skb(xdp->data_hard_start, truesize);
+ skb = napi_build_skb(xdp->data_hard_start, xdp->frame_sz);
if (unlikely(!skb))
return NULL;

@@ -1017,13 +1006,9 @@ ice_construct_skb(struct ice_rx_ring *rx_ring, struct ice_rx_buf *rx_buf,
/* if we exhaust the linear part then add what is left as a frag */
size -= headlen;
if (size) {
-#if (PAGE_SIZE >= 8192)
- unsigned int truesize = SKB_DATA_ALIGN(size);
-#else
- unsigned int truesize = ice_rx_pg_size(rx_ring) / 2;
-#endif
skb_add_rx_frag(skb, 0, rx_buf->page,
- rx_buf->page_offset + headlen, size, truesize);
+ rx_buf->page_offset + headlen, size,
+ xdp->frame_sz);
} else {
/* buffer is unused, change the act that should be taken later
* on; data was copied onto skb's linear part so there's no
@@ -1176,7 +1161,7 @@ int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)
continue;
construct_skb:
if (skb) {
- ice_add_rx_frag(rx_ring, rx_buf, skb, size);
+ ice_add_rx_frag(rx_ring, xdp, rx_buf, skb, size);
} else if (likely(xdp->data)) {
if (ice_ring_uses_build_skb(rx_ring))
skb = ice_build_skb(rx_ring, rx_buf, xdp);
--
2.34.1