Since commit 71ce391dfb784 ("net: mvpp2: enable proper per-CPU TX
buffers unmapping"), we are not correctly DMA unmapping TX buffers for
fragments.
Indeed, the mvpp2_txq_inc_put() function only stores in the
txq_cpu->tx_buffs[] array the physical address of the buffer to be
DMA-unmapped when skb != NULL. In addition, when DMA-unmapping, we use
skb_headlen(skb) to get the size to be unmapped. Both of this works fine
for TX descriptors that are associated directly to a SKB, but not the
ones that are used for fragments, with a NULL pointer as skb:
- We have a NULL physical address when calling DMA unmap
- skb_headlen(skb) crashes because skb is NULL
This causes random crashes when fragments are used.
To solve this problem, this commit:
- Stores the physical address of the buffer to be unmapped
unconditionally, regardless of whether it is tied to a SKB or not.
- Adds a txq_cpu->tx_data_size[] array to store the size of the DMA
buffer to be unmapped upon TX completion.
Fixes: 71ce391dfb784 ("net: mvpp2: enable proper per-CPU TX buffers unmapping")
Reported-by: Raphael G <raphael.g...@corp.ovh.com>
Cc: Raphael G <raphael.g...@corp.ovh.com>
Cc: sta...@vger.kernel.org
Signed-off-by: Thomas Petazzoni <thomas.petazz...@free-electrons.com>
---
drivers/net/ethernet/marvell/mvpp2.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/marvell/mvpp2.c
b/drivers/net/ethernet/marvell/mvpp2.c
index 1026c45..d168b13 100644
--- a/drivers/net/ethernet/marvell/mvpp2.c
+++ b/drivers/net/ethernet/marvell/mvpp2.c
@@ -791,6 +791,8 @@ struct mvpp2_txq_pcpu {
/* Array of transmitted buffers' physical addresses */
dma_addr_t *tx_buffs;
+ size_t *tx_data_size;
+
/* Index of last TX DMA descriptor that was inserted */
int txq_put_index;
@@ -980,9 +982,10 @@ static void mvpp2_txq_inc_put(struct mvpp2_txq_pcpu
*txq_pcpu,
struct mvpp2_tx_desc *tx_desc)
{
txq_pcpu->tx_skb[txq_pcpu->txq_put_index] = skb;
- if (skb)
- txq_pcpu->tx_buffs[txq_pcpu->txq_put_index] =
- tx_desc->buf_phys_addr;
+ txq_pcpu->tx_data_size[txq_pcpu->txq_put_index] =
+ tx_desc->data_size;
+ txq_pcpu->tx_buffs[txq_pcpu->txq_put_index] =
+ tx_desc->buf_phys_addr;
txq_pcpu->txq_put_index++;
if (txq_pcpu->txq_put_index == txq_pcpu->size)
txq_pcpu->txq_put_index = 0;
@@ -4404,11 +4407,13 @@ static void mvpp2_txq_bufs_free(struct mvpp2_port *port,
dma_addr_t buf_phys_addr =
txq_pcpu->tx_buffs[txq_pcpu->txq_get_index];
struct sk_buff *skb = txq_pcpu->tx_skb[txq_pcpu->txq_get_index];
+ size_t data_size =
+ txq_pcpu->tx_data_size[txq_pcpu->txq_get_index];
mvpp2_txq_inc_get(txq_pcpu);
dma_unmap_single(port->dev->dev.parent, buf_phys_addr,
- skb_headlen(skb), DMA_TO_DEVICE);
+ data_size, DMA_TO_DEVICE);
if (!skb)
continue;
dev_kfree_skb_any(skb);
@@ -4662,6 +4667,11 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
if (!txq_pcpu->tx_buffs)
goto error;
+ txq_pcpu->tx_data_size = kmalloc(txq_pcpu->size *
+ sizeof(size_t), GFP_KERNEL);
+ if (!txq_pcpu->tx_data_size)
+ goto error;
+
txq_pcpu->count = 0;
txq_pcpu->reserved_num = 0;
txq_pcpu->txq_put_index = 0;
@@ -4675,6 +4685,7 @@ static int mvpp2_txq_init(struct mvpp2_port *port,
txq_pcpu = per_cpu_ptr(txq->pcpu, cpu);
kfree(txq_pcpu->tx_skb);
kfree(txq_pcpu->tx_buffs);
+ kfree(txq_pcpu->tx_data_size);
}
dma_free_coherent(port->dev->dev.parent,
@@ -4695,6 +4706,7 @@ static void mvpp2_txq_deinit(struct mvpp2_port *port,
txq_pcpu = per_cpu_ptr(txq->pcpu, cpu);
kfree(txq_pcpu->tx_skb);
kfree(txq_pcpu->tx_buffs);
+ kfree(txq_pcpu->tx_data_size);
}
if (txq->descs)
--
2.7.4
