[PATCH v5 net-next 11/13] net: enetc: optimize the allocation of tx_bdr

Wei Fang
2024-10-24T07:09:51Z

From: Clark Wang <xiaoning.wang@nxp.com>

There is a situation where num_tx_rings cannot be divided by bdr_int_num.
For example, num_tx_rings is 8 and bdr_int_num is 3. According to the
previous logic, this results in two tx_bdr corresponding memories not
being allocated, so when sending packets to tx ring 6 or 7, wild pointers
will be accessed. Of course, this issue doesn't exist on LS1028A, because
its num_tx_rings is 8, and bdr_int_num is either 1 or 2. However, there
is a risk for the upcoming i.MX95. Therefore, it is necessary to ensure
that each tx_bdr can be allocated to the corresponding memory.

Signed-off-by: Clark Wang <xiaoning.wang@nxp.com>
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
v5: no changes
---
drivers/net/ethernet/freescale/enetc/enetc.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index bd725561b8a2..bccbeb1f355c 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -3049,10 +3049,10 @@ static void enetc_int_vector_destroy(struct enetc_ndev_priv *priv, int i)
int enetc_alloc_msix(struct enetc_ndev_priv *priv)
{
struct pci_dev *pdev = priv->si->pdev;
+ int v_tx_rings, v_remainder;
int num_stack_tx_queues;
int first_xdp_tx_ring;
int i, n, err, nvec;
- int v_tx_rings;

nvec = ENETC_BDR_INT_BASE_IDX + priv->bdr_int_num;
/* allocate MSIX for both messaging and Rx/Tx interrupts */
@@ -3066,9 +3066,12 @@ int enetc_alloc_msix(struct enetc_ndev_priv *priv)

/* # of tx rings per int vector */
v_tx_rings = priv->num_tx_rings / priv->bdr_int_num;
+ v_remainder = priv->num_tx_rings % priv->bdr_int_num;

for (i = 0; i < priv->bdr_int_num; i++) {
- err = enetc_int_vector_init(priv, i, v_tx_rings);
+ int num_tx_rings = i < v_remainder ? v_tx_rings + 1 : v_tx_rings;
+
+ err = enetc_int_vector_init(priv, i, num_tx_rings);
if (err)
goto fail;
}
--
2.34.1