bnxt_en: Fix first buffer size calculations for XDP multi-buffer

The size of the first buffer is always page size, and the useable
space is the page size minus the offset and the skb_shared_info size.
Make sure SKB and XDP buf sizes match so that the skb_shared_info
is at the same offset seen from the SKB and XDP_BUF.

build_skb() should be passed PAGE_SIZE.  xdp_init_buff() should
be passed PAGE_SIZE as well.  xdp_get_shared_info_from_buff() will
automatically deduct the skb_shared_info size if the XDP buffer
has frags.  There is no need to keep bp->xdp_has_frags.

Change BNXT_PAGE_MODE_BUF_SIZE to BNXT_MAX_PAGE_MODE_MTU_SBUF
since this constant is really the MTU with ethernet header size
subtracted.

Also fix the BNXT_MAX_PAGE_MODE_MTU macro with proper parentheses.

Fixes: 32861236190b ("bnxt: change receive ring space parameters")
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 1acabfe..a21c682 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -991,8 +991,7 @@ static struct sk_buff *bnxt_rx_multi_page_skb(struct bnxt *bp,
        dma_addr -= bp->rx_dma_offset;
        dma_unmap_page_attrs(&bp->pdev->dev, dma_addr, PAGE_SIZE, bp->rx_dir,
                             DMA_ATTR_WEAK_ORDERING);
-       skb = build_skb(page_address(page), BNXT_PAGE_MODE_BUF_SIZE +
-                                           bp->rx_dma_offset);
+       skb = build_skb(page_address(page), PAGE_SIZE);
        if (!skb) {
                __free_page(page);
                return NULL;
@@ -3969,8 +3968,10 @@ void bnxt_set_ring_params(struct bnxt *bp)
                bp->rx_agg_ring_mask = (bp->rx_agg_nr_pages * RX_DESC_CNT) - 1;
 
                if (BNXT_RX_PAGE_MODE(bp)) {
-                       rx_space = BNXT_PAGE_MODE_BUF_SIZE;
-                       rx_size = BNXT_MAX_PAGE_MODE_MTU;
+                       rx_space = PAGE_SIZE;
+                       rx_size = PAGE_SIZE -
+                                 ALIGN(max(NET_SKB_PAD, XDP_PACKET_HEADROOM), 8) -
+                                 SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
                } else {
                        rx_size = SKB_DATA_ALIGN(BNXT_RX_COPY_THRESH + NET_IP_ALIGN);
                        rx_space = rx_size + NET_SKB_PAD +

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 41c6dd0..5163ef4 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -591,12 +591,20 @@ struct nqe_cn {
 #define BNXT_RX_PAGE_SIZE (1 << BNXT_RX_PAGE_SHIFT)
 
 #define BNXT_MAX_MTU           9500
-#define BNXT_PAGE_MODE_BUF_SIZE \
+
+/* First RX buffer page in XDP multi-buf mode
+ *
+ * +-------------------------------------------------------------------------+
+ * | XDP_PACKET_HEADROOM | bp->rx_buf_use_size              | skb_shared_info|
+ * | (bp->rx_dma_offset) |                                  |                |
+ * +-------------------------------------------------------------------------+
+ */
+#define BNXT_MAX_PAGE_MODE_MTU_SBUF \
        ((unsigned int)PAGE_SIZE - VLAN_ETH_HLEN - NET_IP_ALIGN -       \
         XDP_PACKET_HEADROOM)
 #define BNXT_MAX_PAGE_MODE_MTU \
-       BNXT_PAGE_MODE_BUF_SIZE - \
-       SKB_DATA_ALIGN((unsigned int)sizeof(struct skb_shared_info))
+       (BNXT_MAX_PAGE_MODE_MTU_SBUF - \
+        SKB_DATA_ALIGN((unsigned int)sizeof(struct skb_shared_info)))
 
 #define BNXT_MIN_PKT_SIZE      52
 
@@ -2134,7 +2142,6 @@ struct bnxt {
 #define BNXT_DUMP_CRASH                1
 
        struct bpf_prog         *xdp_prog;
-       u8                      xdp_has_frags;
 
        struct bnxt_ptp_cfg     *ptp_cfg;
        u8                      ptp_all_rx_tstamp;

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
index 2ceeaa8..36d5202 100644 (file)
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c
@@ -193,9 +193,6 @@ void bnxt_xdp_buff_init(struct bnxt *bp, struct bnxt_rx_ring_info *rxr,
        mapping = rx_buf->mapping - bp->rx_dma_offset;
        dma_sync_single_for_cpu(&pdev->dev, mapping + offset, len, bp->rx_dir);
 
-       if (bp->xdp_has_frags)
-               buflen = BNXT_PAGE_MODE_BUF_SIZE + offset;
-
        xdp_init_buff(xdp, buflen, &rxr->xdp_rxq);
        xdp_prepare_buff(xdp, data_ptr - offset, offset, len, false);
 }
@@ -404,10 +401,8 @@ static int bnxt_xdp_set(struct bnxt *bp, struct bpf_prog *prog)
                netdev_warn(dev, "ethtool rx/tx channels must be combined to support XDP.\n");
                return -EOPNOTSUPP;
        }
-       if (prog) {
+       if (prog)
                tx_xdp = bp->rx_nr_rings;
-               bp->xdp_has_frags = prog->aux->xdp_has_frags;
-       }
 
        tc = netdev_get_num_tc(dev);
        if (!tc)