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authorVladimir Oltean <vladimir.oltean@nxp.com>2020-03-10 03:28:18 +0200
committerDavid S. Miller <davem@davemloft.net>2020-03-09 18:58:17 -0700
commita8015ded89ad740d21355470d41879c5bd82aab7 (patch)
tree0a1b1598c37cc919cd29e420eac160a9694c4cc8 /drivers/net/ethernet
parentipvlan: do not use cond_resched_rcu() in ipvlan_process_multicast() (diff)
downloadlinux-dev-a8015ded89ad740d21355470d41879c5bd82aab7.tar.xz
linux-dev-a8015ded89ad740d21355470d41879c5bd82aab7.zip
net: mscc: ocelot: properly account for VLAN header length when setting MRU
What the driver writes into MAC_MAXLEN_CFG does not actually represent VLAN_ETH_FRAME_LEN but instead ETH_FRAME_LEN + ETH_FCS_LEN. Yes they are numerically equal, but the difference is important, as the switch treats VLAN-tagged traffic specially and knows to increase the maximum accepted frame size automatically. So it is always wrong to account for VLAN in the MAC_MAXLEN_CFG register. Unconditionally increase the maximum allowed frame size for double-tagged traffic. Accounting for the additional length does not mean that the other VLAN membership checks aren't performed, so there's no harm done. Also, stop abusing the MTU name for configuring the MRU. There is no support for configuring the MRU on an interface at the moment. Fixes: a556c76adc05 ("net: mscc: Add initial Ocelot switch support") Fixes: fa914e9c4d94 ("net: mscc: ocelot: create a helper for changing the port MTU") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet')
-rw-r--r--drivers/net/ethernet/mscc/ocelot.c28
1 files changed, 17 insertions, 11 deletions
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 86d543ab1ab9..d3b7373c5961 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -2176,24 +2176,29 @@ static int ocelot_init_timestamp(struct ocelot *ocelot)
return 0;
}
-static void ocelot_port_set_mtu(struct ocelot *ocelot, int port, size_t mtu)
+/* Configure the maximum SDU (L2 payload) on RX to the value specified in @sdu.
+ * The length of VLAN tags is accounted for automatically via DEV_MAC_TAGS_CFG.
+ */
+static void ocelot_port_set_maxlen(struct ocelot *ocelot, int port, size_t sdu)
{
struct ocelot_port *ocelot_port = ocelot->ports[port];
+ int maxlen = sdu + ETH_HLEN + ETH_FCS_LEN;
int atop_wm;
- ocelot_port_writel(ocelot_port, mtu, DEV_MAC_MAXLEN_CFG);
+ ocelot_port_writel(ocelot_port, maxlen, DEV_MAC_MAXLEN_CFG);
/* Set Pause WM hysteresis
- * 152 = 6 * mtu / OCELOT_BUFFER_CELL_SZ
- * 101 = 4 * mtu / OCELOT_BUFFER_CELL_SZ
+ * 152 = 6 * maxlen / OCELOT_BUFFER_CELL_SZ
+ * 101 = 4 * maxlen / OCELOT_BUFFER_CELL_SZ
*/
ocelot_write_rix(ocelot, SYS_PAUSE_CFG_PAUSE_ENA |
SYS_PAUSE_CFG_PAUSE_STOP(101) |
SYS_PAUSE_CFG_PAUSE_START(152), SYS_PAUSE_CFG, port);
/* Tail dropping watermark */
- atop_wm = (ocelot->shared_queue_sz - 9 * mtu) / OCELOT_BUFFER_CELL_SZ;
- ocelot_write_rix(ocelot, ocelot_wm_enc(9 * mtu),
+ atop_wm = (ocelot->shared_queue_sz - 9 * maxlen) /
+ OCELOT_BUFFER_CELL_SZ;
+ ocelot_write_rix(ocelot, ocelot_wm_enc(9 * maxlen),
SYS_ATOP, port);
ocelot_write(ocelot, ocelot_wm_enc(atop_wm), SYS_ATOP_TOT_CFG);
}
@@ -2222,9 +2227,10 @@ void ocelot_init_port(struct ocelot *ocelot, int port)
DEV_MAC_HDX_CFG);
/* Set Max Length and maximum tags allowed */
- ocelot_port_set_mtu(ocelot, port, VLAN_ETH_FRAME_LEN);
+ ocelot_port_set_maxlen(ocelot, port, ETH_DATA_LEN);
ocelot_port_writel(ocelot_port, DEV_MAC_TAGS_CFG_TAG_ID(ETH_P_8021AD) |
DEV_MAC_TAGS_CFG_VLAN_AWR_ENA |
+ DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA |
DEV_MAC_TAGS_CFG_VLAN_LEN_AWR_ENA,
DEV_MAC_TAGS_CFG);
@@ -2310,18 +2316,18 @@ void ocelot_set_cpu_port(struct ocelot *ocelot, int cpu,
* Only one port can be an NPI at the same time.
*/
if (cpu < ocelot->num_phys_ports) {
- int mtu = VLAN_ETH_FRAME_LEN + OCELOT_TAG_LEN;
+ int sdu = ETH_DATA_LEN + OCELOT_TAG_LEN;
ocelot_write(ocelot, QSYS_EXT_CPU_CFG_EXT_CPUQ_MSK_M |
QSYS_EXT_CPU_CFG_EXT_CPU_PORT(cpu),
QSYS_EXT_CPU_CFG);
if (injection == OCELOT_TAG_PREFIX_SHORT)
- mtu += OCELOT_SHORT_PREFIX_LEN;
+ sdu += OCELOT_SHORT_PREFIX_LEN;
else if (injection == OCELOT_TAG_PREFIX_LONG)
- mtu += OCELOT_LONG_PREFIX_LEN;
+ sdu += OCELOT_LONG_PREFIX_LEN;
- ocelot_port_set_mtu(ocelot, cpu, mtu);
+ ocelot_port_set_maxlen(ocelot, cpu, sdu);
}
/* CPU port Injection/Extraction configuration */