net: stmmac: Convert prefetch() to net_prefetch() for received frames

The size of DMA descriptors is 32 bytes at most.
net_prefetch() for received frames, and keep prefetch() for descriptors.

This patch brings ~4.8% driver performance improvement in a TCP RX
throughput test with iPerf tool on a single isolated Cortex-A65 CPU
core, 2.92 Gbits/sec increased to 3.06 Gbits/sec.

Suggested-by: Joe Damato <jdamato@fastly.com>
Signed-off-by: Furong Xu <0x1207@gmail.com>
Reviewed-by: Yanteng Si <si.yanteng@linux.dev>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: Joe Damato <jdamato@fastly.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ad928e8e21a950dd05acb9b7cad2ecf6eac34ce8..49b41148d594e682bd6db25ad45c58a44b1fb28b 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -5529,7 +5529,8 @@ read_again:
 
                        dma_sync_single_for_cpu(priv->device, buf->addr,
                                                buf1_len, dma_dir);
-                       prefetch(page_address(buf->page) + buf->page_offset);
+                       net_prefetch(page_address(buf->page) +
+                                    buf->page_offset);
 
                        xdp_init_buff(&ctx.xdp, buf_sz, &rx_q->xdp_rxq);
                        xdp_prepare_buff(&ctx.xdp, page_address(buf->page),