From 9405a8fee2608131f607ab16667d2f85eaf7710e Mon Sep 17 00:00:00 2001
From: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Tue, 10 Mar 2020 03:28:18 +0200
Subject: [PATCH 09/12] net: mscc: ocelot: properly account for VLAN header
length when setting MRU
Git-commit: a8015ded89ad740d21355470d41879c5bd82aab7
Patch-mainline: v5.6-rc6
References: git-fixes
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>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/ethernet/mscc/ocelot.c | 28 +++++++++++++++++-----------
include/soc/mscc/ocelot_dev.h | 2 +-
2 files changed, 18 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 18b84d66fd5b..41949e6a3118 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -2183,24 +2183,29 @@ 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);
}
@@ -2229,9 +2234,10 @@ 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);
@@ -2317,18 +2323,18 @@ 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 */
diff --git a/include/soc/mscc/ocelot_dev.h b/include/soc/mscc/ocelot_dev.h
index 0a50d53bbd3f..7c08437061fc 100644
--- a/include/soc/mscc/ocelot_dev.h
+++ b/include/soc/mscc/ocelot_dev.h
@@ -74,7 +74,7 @@
#define DEV_MAC_TAGS_CFG_TAG_ID_M GENMASK(31, 16)
#define DEV_MAC_TAGS_CFG_TAG_ID_X(x) (((x) & GENMASK(31, 16)) >> 16)
#define DEV_MAC_TAGS_CFG_VLAN_LEN_AWR_ENA BIT(2)
-#define DEV_MAC_TAGS_CFG_PB_ENA BIT(1)
+#define DEV_MAC_TAGS_CFG_VLAN_DBL_AWR_ENA BIT(1)
#define DEV_MAC_TAGS_CFG_VLAN_AWR_ENA BIT(0)
#define DEV_MAC_ADV_CHK_CFG 0x2c
--
2.16.4