ethernet: atl1: Add missing DMA mapping error checks and count errors

[ Upstream commit d72411d20905180cdc452c553be17481b24463d2 ]

The `dma_map_XXX()` functions can fail and must be checked using
`dma_mapping_error()`.  This patch adds proper error handling for all
DMA mapping calls.

In `atl1_alloc_rx_buffers()`, if DMA mapping fails, the buffer is
deallocated and marked accordingly.

In `atl1_tx_map()`, previously mapped buffers are unmapped and the
packet is dropped on failure.

If `atl1_xmit_frame()` drops the packet, increment the tx_error counter.

Fixes: f3cc28c79760 ("Add Attansic L1 ethernet driver.")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Link: https://patch.msgid.link/20250625141629.114984-2-fourier.thomas@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
index b498fd6a47d0b0c7004565978b18e39fca8ad929..3e80b9659e3b41a963b8b3bc96a3d3840efcc72b 100644 (file)
--- a/drivers/net/ethernet/atheros/atlx/atl1.c
+++ b/drivers/net/ethernet/atheros/atlx/atl1.c
@@ -1863,14 +1863,21 @@ static u16 atl1_alloc_rx_buffers(struct atl1_adapter *adapter)
                        break;
                }
 
-               buffer_info->alloced = 1;
-               buffer_info->skb = skb;
-               buffer_info->length = (u16) adapter->rx_buffer_len;
                page = virt_to_page(skb->data);
                offset = offset_in_page(skb->data);
                buffer_info->dma = pci_map_page(pdev, page, offset,
                                                adapter->rx_buffer_len,
                                                PCI_DMA_FROMDEVICE);
+               if (pci_dma_mapping_error(pdev, buffer_info->dma)) {
+                       kfree_skb(skb);
+                       adapter->soft_stats.rx_dropped++;
+                       break;
+               }
+
+               buffer_info->alloced = 1;
+               buffer_info->skb = skb;
+               buffer_info->length = (u16)adapter->rx_buffer_len;
+
                rfd_desc->buffer_addr = cpu_to_le64(buffer_info->dma);
                rfd_desc->buf_len = cpu_to_le16(adapter->rx_buffer_len);
                rfd_desc->coalese = 0;
@@ -2182,8 +2189,8 @@ static int atl1_tx_csum(struct atl1_adapter *adapter, struct sk_buff *skb,
        return 0;
 }
 
-static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
-       struct tx_packet_desc *ptpd)
+static bool atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
+                       struct tx_packet_desc *ptpd)
 {
        struct atl1_tpd_ring *tpd_ring = &adapter->tpd_ring;
        struct atl1_buffer *buffer_info;
@@ -2193,6 +2200,7 @@ static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
        unsigned int nr_frags;
        unsigned int f;
        int retval;
+       u16 first_mapped;
        u16 next_to_use;
        u16 data_len;
        u8 hdr_len;
@@ -2200,6 +2208,7 @@ static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
        buf_len -= skb->data_len;
        nr_frags = skb_shinfo(skb)->nr_frags;
        next_to_use = atomic_read(&tpd_ring->next_to_use);
+       first_mapped = next_to_use;
        buffer_info = &tpd_ring->buffer_info[next_to_use];
        BUG_ON(buffer_info->skb);
        /* put skb in last TPD */
@@ -2215,6 +2224,8 @@ static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
                buffer_info->dma = pci_map_page(adapter->pdev, page,
                                                offset, hdr_len,
                                                PCI_DMA_TODEVICE);
+               if (pci_dma_mapping_error(adapter->pdev, buffer_info->dma))
+                       goto dma_err;
 
                if (++next_to_use == tpd_ring->count)
                        next_to_use = 0;
@@ -2240,6 +2251,9 @@ static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
                                buffer_info->dma = pci_map_page(adapter->pdev,
                                        page, offset, buffer_info->length,
                                        PCI_DMA_TODEVICE);
+                               if (pci_dma_mapping_error(adapter->pdev,
+                                                     buffer_info->dma))
+                                       goto dma_err;
                                if (++next_to_use == tpd_ring->count)
                                        next_to_use = 0;
                        }
@@ -2251,6 +2265,8 @@ static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
                offset = offset_in_page(skb->data);
                buffer_info->dma = pci_map_page(adapter->pdev, page,
                        offset, buf_len, PCI_DMA_TODEVICE);
+               if (pci_dma_mapping_error(adapter->pdev, buffer_info->dma))
+                       goto dma_err;
                if (++next_to_use == tpd_ring->count)
                        next_to_use = 0;
        }
@@ -2274,6 +2290,9 @@ static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
                        buffer_info->dma = skb_frag_dma_map(&adapter->pdev->dev,
                                frag, i * ATL1_MAX_TX_BUF_LEN,
                                buffer_info->length, DMA_TO_DEVICE);
+                       if (dma_mapping_error(&adapter->pdev->dev,
+                                             buffer_info->dma))
+                               goto dma_err;
 
                        if (++next_to_use == tpd_ring->count)
                                next_to_use = 0;
@@ -2282,6 +2301,22 @@ static void atl1_tx_map(struct atl1_adapter *adapter, struct sk_buff *skb,
 
        /* last tpd's buffer-info */
        buffer_info->skb = skb;
+
+       return true;
+
+ dma_err:
+       while (first_mapped != next_to_use) {
+               buffer_info = &tpd_ring->buffer_info[first_mapped];
+               pci_unmap_page(adapter->pdev,
+                              buffer_info->dma,
+                              buffer_info->length,
+                              PCI_DMA_TODEVICE);
+               buffer_info->dma = 0;
+
+               if (++first_mapped == tpd_ring->count)
+                       first_mapped = 0;
+       }
+       return false;
 }
 
 static void atl1_tx_queue(struct atl1_adapter *adapter, u16 count,
@@ -2352,10 +2387,8 @@ static netdev_tx_t atl1_xmit_frame(struct sk_buff *skb,
 
        len = skb_headlen(skb);
 
-       if (unlikely(skb->len <= 0)) {
-               dev_kfree_skb_any(skb);
-               return NETDEV_TX_OK;
-       }
+       if (unlikely(skb->len <= 0))
+               goto drop_packet;
 
        nr_frags = skb_shinfo(skb)->nr_frags;
        for (f = 0; f < nr_frags; f++) {
@@ -2369,10 +2402,8 @@ static netdev_tx_t atl1_xmit_frame(struct sk_buff *skb,
                if (skb->protocol == htons(ETH_P_IP)) {
                        proto_hdr_len = (skb_transport_offset(skb) +
                                         tcp_hdrlen(skb));
-                       if (unlikely(proto_hdr_len > len)) {
-                               dev_kfree_skb_any(skb);
-                               return NETDEV_TX_OK;
-                       }
+                       if (unlikely(proto_hdr_len > len))
+                               goto drop_packet;
                        /* need additional TPD ? */
                        if (proto_hdr_len != len)
                                count += (len - proto_hdr_len +
@@ -2404,23 +2435,26 @@ static netdev_tx_t atl1_xmit_frame(struct sk_buff *skb,
        }
 
        tso = atl1_tso(adapter, skb, ptpd);
-       if (tso < 0) {
-               dev_kfree_skb_any(skb);
-               return NETDEV_TX_OK;
-       }
+       if (tso < 0)
+               goto drop_packet;
 
        if (!tso) {
                ret_val = atl1_tx_csum(adapter, skb, ptpd);
-               if (ret_val < 0) {
-                       dev_kfree_skb_any(skb);
-                       return NETDEV_TX_OK;
-               }
+               if (ret_val < 0)
+                       goto drop_packet;
        }
 
-       atl1_tx_map(adapter, skb, ptpd);
+       if (!atl1_tx_map(adapter, skb, ptpd))
+               goto drop_packet;
+
        atl1_tx_queue(adapter, count, ptpd);
        atl1_update_mailbox(adapter);
        return NETDEV_TX_OK;
+
+drop_packet:
+       adapter->soft_stats.tx_errors++;
+       dev_kfree_skb_any(skb);
+       return NETDEV_TX_OK;
 }
 
 static int atl1_rings_clean(struct napi_struct *napi, int budget)