kernel: backport MT7530 ageing time support

Allow setting ageing time from 1 to 1,048,576 seconds.

Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Tested-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Tested-by: Stijn Tintel <stijn@linux-ipv6.be>

diff --git a/target/linux/generic/backport-5.10/764-v5.11-net-dsa-mt7530-support-setting-ageing-time.patch b/target/linux/generic/backport-5.10/764-v5.11-net-dsa-mt7530-support-setting-ageing-time.patch
new file mode 100644 (file)
index 0000000..44fa40e
--- /dev/null
+++ b/target/linux/generic/backport-5.10/764-v5.11-net-dsa-mt7530-support-setting-ageing-time.patch
@@ -0,0 +1,99 @@
+From ea6d5c924e391872d402acac38461a5f8261e57f Mon Sep 17 00:00:00 2001
+From: DENG Qingfang <dqfext@gmail.com>
+Date: Tue, 8 Dec 2020 15:00:28 +0800
+Subject: [PATCH] net: dsa: mt7530: support setting ageing time
+
+MT7530 has a global address age control register, so use it to set
+ageing time.
+
+The applied timer is (AGE_CNT + 1) * (AGE_UNIT + 1) seconds
+
+Signed-off-by: DENG Qingfang <dqfext@gmail.com>
+Reviewed-by: Andrew Lunn <andrew@lunn.ch>
+Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
+Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+ drivers/net/dsa/mt7530.c | 41 ++++++++++++++++++++++++++++++++++++++++
+ drivers/net/dsa/mt7530.h | 13 +++++++++++++
+ 2 files changed, 54 insertions(+)
+
+--- a/drivers/net/dsa/mt7530.c
++++ b/drivers/net/dsa/mt7530.c
+@@ -870,6 +870,46 @@ mt7530_get_sset_count(struct dsa_switch
+       return ARRAY_SIZE(mt7530_mib);
+ }
+ 
++static int
++mt7530_set_ageing_time(struct dsa_switch *ds, unsigned int msecs)
++{
++      struct mt7530_priv *priv = ds->priv;
++      unsigned int secs = msecs / 1000;
++      unsigned int tmp_age_count;
++      unsigned int error = -1;
++      unsigned int age_count;
++      unsigned int age_unit;
++
++      /* Applied timer is (AGE_CNT + 1) * (AGE_UNIT + 1) seconds */
++      if (secs < 1 || secs > (AGE_CNT_MAX + 1) * (AGE_UNIT_MAX + 1))
++              return -ERANGE;
++
++      /* iterate through all possible age_count to find the closest pair */
++      for (tmp_age_count = 0; tmp_age_count <= AGE_CNT_MAX; ++tmp_age_count) {
++              unsigned int tmp_age_unit = secs / (tmp_age_count + 1) - 1;
++
++              if (tmp_age_unit <= AGE_UNIT_MAX) {
++                      unsigned int tmp_error = secs -
++                              (tmp_age_count + 1) * (tmp_age_unit + 1);
++
++                      /* found a closer pair */
++                      if (error > tmp_error) {
++                              error = tmp_error;
++                              age_count = tmp_age_count;
++                              age_unit = tmp_age_unit;
++                      }
++
++                      /* found the exact match, so break the loop */
++                      if (!error)
++                              break;
++              }
++      }
++
++      mt7530_write(priv, MT7530_AAC, AGE_CNT(age_count) | AGE_UNIT(age_unit));
++
++      return 0;
++}
++
+ static void mt7530_setup_port5(struct dsa_switch *ds, phy_interface_t interface)
+ {
+       struct mt7530_priv *priv = ds->priv;
+@@ -2699,6 +2739,7 @@ static const struct dsa_switch_ops mt753
+       .phy_write              = mt753x_phy_write,
+       .get_ethtool_stats      = mt7530_get_ethtool_stats,
+       .get_sset_count         = mt7530_get_sset_count,
++      .set_ageing_time        = mt7530_set_ageing_time,
+       .port_enable            = mt7530_port_enable,
+       .port_disable           = mt7530_port_disable,
+       .port_change_mtu        = mt7530_port_change_mtu,
+--- a/drivers/net/dsa/mt7530.h
++++ b/drivers/net/dsa/mt7530.h
+@@ -161,6 +161,19 @@ enum mt7530_vlan_egress_attr {
+       MT7530_VLAN_EGRESS_STACK = 3,
+ };
+ 
++/* Register for address age control */
++#define MT7530_AAC                    0xa0
++/* Disable ageing */
++#define  AGE_DIS                      BIT(20)
++/* Age count */
++#define  AGE_CNT_MASK                 GENMASK(19, 12)
++#define  AGE_CNT_MAX                  0xff
++#define  AGE_CNT(x)                   (AGE_CNT_MASK & ((x) << 12))
++/* Age unit */
++#define  AGE_UNIT_MASK                        GENMASK(11, 0)
++#define  AGE_UNIT_MAX                 0xfff
++#define  AGE_UNIT(x)                  (AGE_UNIT_MASK & (x))
++
+ /* Register for port STP state control */
+ #define MT7530_SSP_P(x)                       (0x2000 + ((x) * 0x100))
+ #define  FID_PST(x)                   ((x) & 0x3)