5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jose Abreu Jose.Abreu@synopsys.com
[ Upstream commit 88ebe2cf7f3fc9da95e0f06483fd58da3e67e675 ]
This looks over-engineered. Let's use some helpers to get the buffer length and hereby simplify the stmmac_rx() function. No performance drop was seen with the new implementation.
Signed-off-by: Jose Abreu Jose.Abreu@synopsys.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: fa02de9e7588 ("net: stmmac: fix rx budget limit check") Signed-off-by: Sasha Levin sashal@kernel.org --- .../net/ethernet/stmicro/stmmac/stmmac_main.c | 146 +++++++++++------- 1 file changed, 94 insertions(+), 52 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 6a3b0f76d9729..e521ab508f030 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3440,6 +3440,55 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv, u32 queue) stmmac_set_rx_tail_ptr(priv, priv->ioaddr, rx_q->rx_tail_addr, queue); }
+static unsigned int stmmac_rx_buf1_len(struct stmmac_priv *priv, + struct dma_desc *p, + int status, unsigned int len) +{ + int ret, coe = priv->hw->rx_csum; + unsigned int plen = 0, hlen = 0; + + /* Not first descriptor, buffer is always zero */ + if (priv->sph && len) + return 0; + + /* First descriptor, get split header length */ + ret = stmmac_get_rx_header_len(priv, p, &hlen); + if (priv->sph && hlen) { + priv->xstats.rx_split_hdr_pkt_n++; + return hlen; + } + + /* First descriptor, not last descriptor and not split header */ + if (status & rx_not_ls) + return priv->dma_buf_sz; + + plen = stmmac_get_rx_frame_len(priv, p, coe); + + /* First descriptor and last descriptor and not split header */ + return min_t(unsigned int, priv->dma_buf_sz, plen); +} + +static unsigned int stmmac_rx_buf2_len(struct stmmac_priv *priv, + struct dma_desc *p, + int status, unsigned int len) +{ + int coe = priv->hw->rx_csum; + unsigned int plen = 0; + + /* Not split header, buffer is not available */ + if (!priv->sph) + return 0; + + /* Not last descriptor */ + if (status & rx_not_ls) + return priv->dma_buf_sz; + + plen = stmmac_get_rx_frame_len(priv, p, coe); + + /* Last descriptor */ + return plen - len; +} + /** * stmmac_rx - manage the receive process * @priv: driver private structure @@ -3469,11 +3518,10 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) stmmac_display_ring(priv, rx_head, DMA_RX_SIZE, true); } while (count < limit) { - unsigned int hlen = 0, prev_len = 0; + unsigned int buf1_len = 0, buf2_len = 0; enum pkt_hash_types hash_type; struct stmmac_rx_buffer *buf; struct dma_desc *np, *p; - unsigned int sec_len; int entry; u32 hash;
@@ -3492,7 +3540,8 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) break;
read_again: - sec_len = 0; + buf1_len = 0; + buf2_len = 0; entry = next_entry; buf = &rx_q->buf_pool[entry];
@@ -3517,7 +3566,6 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) np = rx_q->dma_rx + next_entry;
prefetch(np); - prefetch(page_address(buf->page));
if (priv->extend_desc) stmmac_rx_extended_status(priv, &priv->dev->stats, @@ -3534,69 +3582,61 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) goto read_again; if (unlikely(error)) { dev_kfree_skb(skb); + skb = NULL; count++; continue; }
/* Buffer is good. Go on. */
- if (likely(status & rx_not_ls)) { - len += priv->dma_buf_sz; - } else { - prev_len = len; - len = stmmac_get_rx_frame_len(priv, p, coe); - - /* ACS is set; GMAC core strips PAD/FCS for IEEE 802.3 - * Type frames (LLC/LLC-SNAP) - * - * llc_snap is never checked in GMAC >= 4, so this ACS - * feature is always disabled and packets need to be - * stripped manually. - */ - if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00) || - unlikely(status != llc_snap)) - len -= ETH_FCS_LEN; + prefetch(page_address(buf->page)); + if (buf->sec_page) + prefetch(page_address(buf->sec_page)); + + buf1_len = stmmac_rx_buf1_len(priv, p, status, len); + len += buf1_len; + buf2_len = stmmac_rx_buf2_len(priv, p, status, len); + len += buf2_len; + + /* ACS is set; GMAC core strips PAD/FCS for IEEE 802.3 + * Type frames (LLC/LLC-SNAP) + * + * llc_snap is never checked in GMAC >= 4, so this ACS + * feature is always disabled and packets need to be + * stripped manually. + */ + if (unlikely(priv->synopsys_id >= DWMAC_CORE_4_00) || + unlikely(status != llc_snap)) { + if (buf2_len) + buf2_len -= ETH_FCS_LEN; + else + buf1_len -= ETH_FCS_LEN; + + len -= ETH_FCS_LEN; }
if (!skb) { - int ret = stmmac_get_rx_header_len(priv, p, &hlen); - - if (priv->sph && !ret && (hlen > 0)) { - sec_len = len; - if (!(status & rx_not_ls)) - sec_len = sec_len - hlen; - len = hlen; - - prefetch(page_address(buf->sec_page)); - priv->xstats.rx_split_hdr_pkt_n++; - } - - skb = napi_alloc_skb(&ch->rx_napi, len); + skb = napi_alloc_skb(&ch->rx_napi, buf1_len); if (!skb) { priv->dev->stats.rx_dropped++; count++; - continue; + goto drain_data; }
- dma_sync_single_for_cpu(priv->device, buf->addr, len, - DMA_FROM_DEVICE); + dma_sync_single_for_cpu(priv->device, buf->addr, + buf1_len, DMA_FROM_DEVICE); skb_copy_to_linear_data(skb, page_address(buf->page), - len); - skb_put(skb, len); + buf1_len); + skb_put(skb, buf1_len);
/* Data payload copied into SKB, page ready for recycle */ page_pool_recycle_direct(rx_q->page_pool, buf->page); buf->page = NULL; - } else { - unsigned int buf_len = len - prev_len; - - if (likely(status & rx_not_ls)) - buf_len = priv->dma_buf_sz; - + } else if (buf1_len) { dma_sync_single_for_cpu(priv->device, buf->addr, - buf_len, DMA_FROM_DEVICE); + buf1_len, DMA_FROM_DEVICE); skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, - buf->page, 0, buf_len, + buf->page, 0, buf1_len, priv->dma_buf_sz);
/* Data payload appended into SKB */ @@ -3604,22 +3644,23 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue) buf->page = NULL; }
- if (sec_len > 0) { + if (buf2_len) { dma_sync_single_for_cpu(priv->device, buf->sec_addr, - sec_len, DMA_FROM_DEVICE); + buf2_len, DMA_FROM_DEVICE); skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, - buf->sec_page, 0, sec_len, + buf->sec_page, 0, buf2_len, priv->dma_buf_sz);
- len += sec_len; - /* Data payload appended into SKB */ page_pool_release_page(rx_q->page_pool, buf->sec_page); buf->sec_page = NULL; }
+drain_data: if (likely(status & rx_not_ls)) goto read_again; + if (!skb) + continue;
/* Got entire packet into SKB. Finish it. */
@@ -3637,13 +3678,14 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit, u32 queue)
skb_record_rx_queue(skb, queue); napi_gro_receive(&ch->rx_napi, skb); + skb = NULL;
priv->dev->stats.rx_packets++; priv->dev->stats.rx_bytes += len; count++; }
- if (status & rx_not_ls) { + if (status & rx_not_ls || skb) { rx_q->state_saved = true; rx_q->state.skb = skb; rx_q->state.error = error;