stmmac: add tx_skbuff_dma to save descriptors used by PTP
This patch adds a new pointer variable called "tx_skbuff_dma" to private
data structure. This variable will holds the physical address of packet
to be transmitted & same will be used to free/unmap the memory once the
corresponding packet is transmitted by device.
Prior to this patch the descriptor buffer pointer(ie des2) itself was
being used for freeing/unmapping the buffer memory. But in case PTP v1
with normal descriptor the field(des2) will be overwritten by device
with timestamp value, hence driver will loose the buffer pointer to be
freed/unmapped.
Signed-off-by: Rayagond Kokatanur <rayagond@vayavyalabs.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ac166be..180eed71 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -661,6 +661,8 @@
GFP_KERNEL);
priv->rx_skbuff = kmalloc_array(rxsize, sizeof(struct sk_buff *),
GFP_KERNEL);
+ priv->tx_skbuff_dma = kmalloc_array(txsize, sizeof(dma_addr_t),
+ GFP_KERNEL);
priv->tx_skbuff = kmalloc_array(txsize, sizeof(struct sk_buff *),
GFP_KERNEL);
if (netif_msg_drv(priv))
@@ -710,6 +712,7 @@
else
p = priv->dma_tx + i;
p->des2 = 0;
+ priv->tx_skbuff_dma[i] = 0;
priv->tx_skbuff[i] = NULL;
}
@@ -748,12 +751,14 @@
else
p = priv->dma_tx + i;
- if (p->des2)
- dma_unmap_single(priv->device, p->des2,
+ if (priv->tx_skbuff_dma[i])
+ dma_unmap_single(priv->device,
+ priv->tx_skbuff_dma[i],
priv->hw->desc->get_tx_len(p),
DMA_TO_DEVICE);
dev_kfree_skb_any(priv->tx_skbuff[i]);
priv->tx_skbuff[i] = NULL;
+ priv->tx_skbuff_dma[i] = 0;
}
}
}
@@ -783,6 +788,7 @@
}
kfree(priv->rx_skbuff_dma);
kfree(priv->rx_skbuff);
+ kfree(priv->tx_skbuff_dma);
kfree(priv->tx_skbuff);
}
@@ -854,10 +860,13 @@
TX_DBG("%s: curr %d, dirty %d\n", __func__,
priv->cur_tx, priv->dirty_tx);
- if (likely(p->des2))
- dma_unmap_single(priv->device, p->des2,
+ if (likely(priv->tx_skbuff_dma[entry])) {
+ dma_unmap_single(priv->device,
+ priv->tx_skbuff_dma[entry],
priv->hw->desc->get_tx_len(p),
DMA_TO_DEVICE);
+ priv->tx_skbuff_dma[entry] = 0;
+ }
if (priv->mode == STMMAC_RING_MODE)
priv->hw->ring->clean_desc3(p);
@@ -1423,6 +1432,7 @@
if (likely(!is_jumbo)) {
desc->des2 = dma_map_single(priv->device, skb->data,
nopaged_len, DMA_TO_DEVICE);
+ priv->tx_skbuff_dma[entry] = desc->des2;
priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len,
csum_insertion, priv->mode);
} else
@@ -1441,6 +1451,7 @@
TX_DBG("\t[entry %d] segment len: %d\n", entry, len);
desc->des2 = skb_frag_dma_map(priv->device, frag, 0, len,
DMA_TO_DEVICE);
+ priv->tx_skbuff_dma[entry] = desc->des2;
priv->tx_skbuff[entry] = NULL;
priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion,
priv->mode);