ethernet: ionic: Fix DMA mapping tests

Change error values of `ionic_tx_map_single()` and `ionic_tx_map_frag()`
from 0 to `DMA_MAPPING_ERROR` to prevent collision with 0 as a valid
address.

This also fixes the use of `dma_mapping_error()` to test against 0 in
`ionic_xdp_post_frame()`

Fixes: 0f3154e6bcb3 ("ionic: Add Tx and Rx handling")
Fixes: 56e41ee12d2d ("ionic: better dma-map error handling")
Fixes: ac8813c0ab7d ("ionic: convert Rx queue buffers to use page_pool")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Link: https://patch.msgid.link/20250619094538.283723-2-fourier.thomas@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
index 2ac59564ded188e00739fe4487f012cdb90921ef..d10b58ebf6034afa219612fac98119673382e46f 100644 (file)
--- a/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
+++ b/drivers/net/ethernet/pensando/ionic/ionic_txrx.c
@@ -321,7 +321,7 @@ static int ionic_xdp_post_frame(struct ionic_queue *q, struct xdp_frame *frame,
                                           len, DMA_TO_DEVICE);
        } else /* XDP_REDIRECT */ {
                dma_addr = ionic_tx_map_single(q, frame->data, len);
-               if (!dma_addr)
+               if (dma_addr == DMA_MAPPING_ERROR)
                        return -EIO;
        }
 
@@ -357,7 +357,7 @@ static int ionic_xdp_post_frame(struct ionic_queue *q, struct xdp_frame *frame,
                        } else {
                                dma_addr = ionic_tx_map_frag(q, frag, 0,
                                                             skb_frag_size(frag));
-                               if (dma_mapping_error(q->dev, dma_addr)) {
+                               if (dma_addr == DMA_MAPPING_ERROR) {
                                        ionic_tx_desc_unmap_bufs(q, desc_info);
                                        return -EIO;
                                }
@@ -1083,7 +1083,7 @@ static dma_addr_t ionic_tx_map_single(struct ionic_queue *q,
                net_warn_ratelimited("%s: DMA single map failed on %s!\n",
                                     dev_name(dev), q->name);
                q_to_tx_stats(q)->dma_map_err++;
-               return 0;
+               return DMA_MAPPING_ERROR;
        }
        return dma_addr;
 }
@@ -1100,7 +1100,7 @@ static dma_addr_t ionic_tx_map_frag(struct ionic_queue *q,
                net_warn_ratelimited("%s: DMA frag map failed on %s!\n",
                                     dev_name(dev), q->name);
                q_to_tx_stats(q)->dma_map_err++;
-               return 0;
+               return DMA_MAPPING_ERROR;
        }
        return dma_addr;
 }
@@ -1116,7 +1116,7 @@ static int ionic_tx_map_skb(struct ionic_queue *q, struct sk_buff *skb,
        int frag_idx;
 
        dma_addr = ionic_tx_map_single(q, skb->data, skb_headlen(skb));
-       if (!dma_addr)
+       if (dma_addr == DMA_MAPPING_ERROR)
                return -EIO;
        buf_info->dma_addr = dma_addr;
        buf_info->len = skb_headlen(skb);
@@ -1126,7 +1126,7 @@ static int ionic_tx_map_skb(struct ionic_queue *q, struct sk_buff *skb,
        nfrags = skb_shinfo(skb)->nr_frags;
        for (frag_idx = 0; frag_idx < nfrags; frag_idx++, frag++) {
                dma_addr = ionic_tx_map_frag(q, frag, 0, skb_frag_size(frag));
-               if (!dma_addr)
+               if (dma_addr == DMA_MAPPING_ERROR)
                        goto dma_fail;
                buf_info->dma_addr = dma_addr;
                buf_info->len = skb_frag_size(frag);