| Message ID | 20201208070028.3177-1-dqfext@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [net-next] net: dsa: mt7530: support setting ageing time | expand |
On Tue, Dec 08, 2020 at 03:00:28PM +0800, DENG Qingfang wrote: > 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> Andrew
On Tue, Dec 08, 2020 at 03:00:28PM +0800, DENG Qingfang wrote: > 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> > --- > drivers/net/dsa/mt7530.c | 41 ++++++++++++++++++++++++++++++++++++++++ > drivers/net/dsa/mt7530.h | 13 +++++++++++++ > 2 files changed, 54 insertions(+) > > diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c > index 6408402a44f5..99bf8fed6536 100644 > --- a/drivers/net/dsa/mt7530.c > +++ b/drivers/net/dsa/mt7530.c > @@ -870,6 +870,46 @@ mt7530_get_sset_count(struct dsa_switch *ds, int port, int sset) > 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; > + } I feel that the error calculation is just snake oil. This would be enough: if (tmp_age_unit <= AGE_UNIT_MAX) break; Explanation: You are given a number X, and must find A and B such that the error E = |(A x B) - X| should be minimum, with 1 <= A <= A_max 1 <= B <= B_max It is logical to try with A=1 first. If X / A <= B_max, then of course, B = X / 1, and the error E is 0. If that doesn't work out, and B > B_max, then you go to A=2. That gives you another B = X / 2, and the error E is 1. You check again if B <= B_max. If it is, that's your answer. B = X / 2, with an error E of 1. You get my point. Iterating ascendingly through A, and calculating B as X / A, already gives you the smallest error as soon as it satisfies the B <= B_max requirement. > + > + /* 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; > @@ -2564,6 +2604,7 @@ static const struct dsa_switch_ops mt7530_switch_ops = { > .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, > diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h > index ee3523a7537e..32d8969b3ace 100644 > --- 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) > -- > 2.25.1 >
On Tue, Dec 08, 2020 at 10:56:21PM +0200, Vladimir Oltean wrote: > On Tue, Dec 08, 2020 at 03:00:28PM +0800, DENG Qingfang wrote: > > 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> > > --- > > drivers/net/dsa/mt7530.c | 41 ++++++++++++++++++++++++++++++++++++++++ > > drivers/net/dsa/mt7530.h | 13 +++++++++++++ > > 2 files changed, 54 insertions(+) > > > > diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c > > index 6408402a44f5..99bf8fed6536 100644 > > --- a/drivers/net/dsa/mt7530.c > > +++ b/drivers/net/dsa/mt7530.c > > @@ -870,6 +870,46 @@ mt7530_get_sset_count(struct dsa_switch *ds, int port, int sset) > > 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; > > + } > > I feel that the error calculation is just snake oil. This would be enough: > > if (tmp_age_unit <= AGE_UNIT_MAX) > break; > > Explanation: > > You are given a number X, and must find A and B such that the error > E = |(A x B) - X| should be minimum, with > 1 <= A <= A_max > 1 <= B <= B_max > > It is logical to try with A=1 first. If X / A <= B_max, then of course, > B = X / 1, and the error E is 0. > > If that doesn't work out, and B > B_max, then you go to A=2. That gives > you another B = X / 2, and the error E is 1. You check again if B <= > B_max. If it is, that's your answer. B = X / 2, with an error E of 1. > > You get my point. Iterating ascendingly through A, and calculating B as > X / A, already gives you the smallest error as soon as it satisfies the > B <= B_max requirement. > > > + > > + /* 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; > > +} Thinking more about it, it's not snake oil but is actually correct. Where I was wrong was the division giving you a certain error, but it actually only gives a maximum error. Other, larger, divisors can still give you an error of 0. If the number you're searching for, X, is, say, a multiple of 3 but not of 2, and is: B_max * 1 < X < B_max * 2 then exiting the loop at A=2 would give you an error E=1. But if you continued the loop, then A=3 would have yielded an error E=0, because X is a multiple of 3 but not of 2. I should probably go and refresh my basic arithmetic. Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
On 12/7/20 11:00 PM, DENG Qingfang wrote: > 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: Florian Fainelli <f.fainelli@gmail.com>
From: DENG Qingfang <dqfext@gmail.com> Date: Tue, 8 Dec 2020 15:00:28 +0800 > 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> Applied, thanks
diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c index 6408402a44f5..99bf8fed6536 100644 --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -870,6 +870,46 @@ mt7530_get_sset_count(struct dsa_switch *ds, int port, int sset) 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; @@ -2564,6 +2604,7 @@ static const struct dsa_switch_ops mt7530_switch_ops = { .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, diff --git a/drivers/net/dsa/mt7530.h b/drivers/net/dsa/mt7530.h index ee3523a7537e..32d8969b3ace 100644 --- 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)
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> --- drivers/net/dsa/mt7530.c | 41 ++++++++++++++++++++++++++++++++++++++++ drivers/net/dsa/mt7530.h | 13 +++++++++++++ 2 files changed, 54 insertions(+)