2019-07-28 17:37:17

by Matteo Croce

Subject: [PATCH net v2] mvpp2: refactor the HW checksum setup

The hardware can only offload checksum calculation on first port due to
the Tx FIFO size limitation, and has a maximum L3 offset of 128 bytes.
Document this in a comment and move duplicated code in a function.

Fixes: 576193f2d579 ("net: mvpp2: jumbo frames support")
Signed-off-by: Matteo Croce <[email protected]>
---
.../net/ethernet/marvell/mvpp2/mvpp2_main.c | 35 ++++++++++++-------
1 file changed, 22 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 937e4b928b94..a99405135046 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -811,6 +811,26 @@ static int mvpp2_swf_bm_pool_init(struct mvpp2_port *port)
return 0;
}

+static void mvpp2_set_hw_csum(struct mvpp2_port *port,
+ enum mvpp2_bm_pool_log_num new_long_pool)
+{
+ const netdev_features_t csums = NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
+
+ /* Update L4 checksum when jumbo enable/disable on port.
+ * Only port 0 supports hardware checksum offload due to
+ * the Tx FIFO size limitation.
+ * Also, don't set NETIF_F_HW_CSUM because L3_offset in TX descriptor
+ * has 7 bits, so the maximum L3 offset is 128.
+ */
+ if (new_long_pool == MVPP2_BM_JUMBO && port->id != 0) {
+ port->dev->features &= ~csums;
+ port->dev->hw_features &= ~csums;
+ } else {
+ port->dev->features |= csums;
+ port->dev->hw_features |= csums;
+ }
+}
+
static int mvpp2_bm_update_mtu(struct net_device *dev, int mtu)
{
struct mvpp2_port *port = netdev_priv(dev);
@@ -843,15 +863,7 @@ static int mvpp2_bm_update_mtu(struct net_device *dev, int mtu)
/* Add port to new short & long pool */
mvpp2_swf_bm_pool_init(port);

- /* Update L4 checksum when jumbo enable/disable on port */
- if (new_long_pool == MVPP2_BM_JUMBO && port->id != 0) {
- dev->features &= ~(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
- dev->hw_features &= ~(NETIF_F_IP_CSUM |
- NETIF_F_IPV6_CSUM);
- } else {
- dev->features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
- dev->hw_features |= NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM;
- }
+ mvpp2_set_hw_csum(port, new_long_pool);
}

dev->mtu = mtu;
@@ -5209,10 +5221,7 @@ static int mvpp2_port_probe(struct platform_device *pdev,
dev->features |= NETIF_F_NTUPLE;
}

- if (port->pool_long->id == MVPP2_BM_JUMBO && port->id != 0) {
- dev->features &= ~(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
- dev->hw_features &= ~(NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM);
- }
+ mvpp2_set_hw_csum(port, port->pool_long->id);

dev->vlan_features |= features;
dev->gso_max_segs = MVPP2_MAX_TSO_SEGS;
--
2.21.0

2019-07-29 22:01:19

by David Miller

Subject: Re: [PATCH net v2] mvpp2: refactor the HW checksum setup

From: Matteo Croce <[email protected]>
Date: Sun, 28 Jul 2019 19:35:49 +0200

> The hardware can only offload checksum calculation on first port due to
> the Tx FIFO size limitation, and has a maximum L3 offset of 128 bytes.
> Document this in a comment and move duplicated code in a function.
>
> Fixes: 576193f2d579 ("net: mvpp2: jumbo frames support")
> Signed-off-by: Matteo Croce <[email protected]>

Applied.