[PATCH net v2 0/5] net: dsa: b53: Various ARL fixes

[PATCH net v2 0/5] net: dsa: b53: Various ARL fixes

[Florian Fainelli]

Hi David, Andrew, Vivien, Jakub,

This patch series fixes a number of short comings in the existing b53
driver ARL management logic in particular:

- we were not looking up the {MAC,VID} tuples against their VID, despite
  having VLANs enabled

- the MDB entries (multicast) would lose their validity as soon as a
  single port in the vector would leave the entry

- the ARL was currently under utilized because we would always place new
  entries in bin index #1, instead of using all possible bins available,
  thus reducing the ARL effective size by 50% or 75% depending on the
  switch generation

- it was possible to overwrite the ARL entries because no proper space
  verification was done

This patch series addresses all of these issues.

Changes in v2:
- added a new patch to correctly flip invidual VLAN learning vs. shared
  VLAN learning depending on the global VLAN state

- added Andrew's R-b tags for patches which did not change

- corrected some verbosity and minor issues in patch #4 to match caller
  expectations, also avoid a variable length DECLARE_BITMAP() call

Florian Fainelli (5):
  net: dsa: b53: Lookup VID in ARL searches when VLAN is enabled
  net: dsa: b53: Fix valid setting for MDB entries
  net: dsa: b53: Fix ARL register definitions
  net: dsa: b53: Rework ARL bin logic
  net: dsa: b53: b53_arl_rw_op() needs to select IVL or SVL

 drivers/net/dsa/b53/b53_common.c | 38 +++++++++++++++++++++++++++-----
 drivers/net/dsa/b53/b53_regs.h   |  8 +++++--
 2 files changed, 39 insertions(+), 7 deletions(-)

-- 
2.17.1

[PATCH net v2 1/5] net: dsa: b53: Lookup VID in ARL searches when VLAN is enabled

[Florian Fainelli]

When VLAN is enabled, and an ARL search is issued, we also need to
compare the full {MAC,VID} tuple before returning a successful search
result.

Fixes: 1da6df85c6fb ("net: dsa: b53: Implement ARL add/del/dump operations")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/b53/b53_common.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 68e2381694b9..fa9b9aca7b56 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1505,6 +1505,9 @@ static int b53_arl_read(struct b53_device *dev, u64 mac,
 			continue;
 		if ((mac_vid & ARLTBL_MAC_MASK) != mac)
 			continue;
+		if (dev->vlan_enabled &&
+		    ((mac_vid >> ARLTBL_VID_S) & ARLTBL_VID_MASK) != vid)
+			continue;
 		*idx = i;
 	}
 
-- 
2.17.1

[PATCH net v2 2/5] net: dsa: b53: Fix valid setting for MDB entries

[Florian Fainelli]

When support for the MDB entries was added, the valid bit was correctly
changed to be assigned depending on the remaining port bitmask, that is,
if there were no more ports added to the entry's port bitmask, the entry
now becomes invalid. There was another assignment a few lines below that
would override this which would invalidate entries even when there were
still multiple ports left in the MDB entry.

Fixes: 5d65b64a3d97 ("net: dsa: b53: Add support for MDB")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/b53/b53_common.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index fa9b9aca7b56..e937bf365490 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1561,7 +1561,6 @@ static int b53_arl_op(struct b53_device *dev, int op, int port,
 		ent.is_valid = !!(ent.port);
 	}
 
-	ent.is_valid = is_valid;
 	ent.vid = vid;
 	ent.is_static = true;
 	ent.is_age = false;
-- 
2.17.1

[PATCH net v2 3/5] net: dsa: b53: Fix ARL register definitions

[Florian Fainelli]

The ARL {MAC,VID} tuple and the forward entry were off by 0x10 bytes,
which means that when we read/wrote from/to ARL bin index 0, we were
actually accessing the ARLA_RWCTRL register.

Fixes: 1da6df85c6fb ("net: dsa: b53: Implement ARL add/del/dump operations")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/b53/b53_regs.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_regs.h b/drivers/net/dsa/b53/b53_regs.h
index 2a9f421680aa..d914e756cdab 100644
--- a/drivers/net/dsa/b53/b53_regs.h
+++ b/drivers/net/dsa/b53/b53_regs.h
@@ -304,7 +304,7 @@
  *
  * BCM5325 and BCM5365 share most definitions below
  */
-#define B53_ARLTBL_MAC_VID_ENTRY(n)	(0x10 * (n))
+#define B53_ARLTBL_MAC_VID_ENTRY(n)	((0x10 * (n)) + 0x10)
 #define   ARLTBL_MAC_MASK		0xffffffffffffULL
 #define   ARLTBL_VID_S			48
 #define   ARLTBL_VID_MASK_25		0xff
@@ -316,7 +316,7 @@
 #define   ARLTBL_VALID_25		BIT(63)
 
 /* ARL Table Data Entry N Registers (32 bit) */
-#define B53_ARLTBL_DATA_ENTRY(n)	((0x10 * (n)) + 0x08)
+#define B53_ARLTBL_DATA_ENTRY(n)	((0x10 * (n)) + 0x18)
 #define   ARLTBL_DATA_PORT_ID_MASK	0x1ff
 #define   ARLTBL_TC(tc)			((3 & tc) << 11)
 #define   ARLTBL_AGE			BIT(14)
-- 
2.17.1

[PATCH net v2 4/5] net: dsa: b53: Rework ARL bin logic

[Florian Fainelli]

When asking the ARL to read a MAC address, we will get a number of bins
returned in a single read. Out of those bins, there can essentially be 3
states:

- all bins are full, we have no space left, and we can either replace an
  existing address or return that full condition

- the MAC address was found, then we need to return its bin index and
  modify that one, and only that one

- the MAC address was not found and we have a least one bin free, we use
  that bin index location then

The code would unfortunately fail on all counts.

Fixes: 1da6df85c6fb ("net: dsa: b53: Implement ARL add/del/dump operations")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/b53/b53_common.c | 30 ++++++++++++++++++++++++++----
 drivers/net/dsa/b53/b53_regs.h   |  3 +++
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index e937bf365490..8cb41583bbad 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1483,6 +1483,7 @@ static int b53_arl_read(struct b53_device *dev, u64 mac,
 			u16 vid, struct b53_arl_entry *ent, u8 *idx,
 			bool is_valid)
 {
+	DECLARE_BITMAP(free_bins, B53_ARLTBL_MAX_BIN_ENTRIES);
 	unsigned int i;
 	int ret;
 
@@ -1490,6 +1491,8 @@ static int b53_arl_read(struct b53_device *dev, u64 mac,
 	if (ret)
 		return ret;
 
+	bitmap_zero(free_bins, dev->num_arl_entries);
+
 	/* Read the bins */
 	for (i = 0; i < dev->num_arl_entries; i++) {
 		u64 mac_vid;
@@ -1501,16 +1504,24 @@ static int b53_arl_read(struct b53_device *dev, u64 mac,
 			   B53_ARLTBL_DATA_ENTRY(i), &fwd_entry);
 		b53_arl_to_entry(ent, mac_vid, fwd_entry);
 
-		if (!(fwd_entry & ARLTBL_VALID))
+		if (!(fwd_entry & ARLTBL_VALID)) {
+			set_bit(i, free_bins);
 			continue;
+		}
 		if ((mac_vid & ARLTBL_MAC_MASK) != mac)
 			continue;
 		if (dev->vlan_enabled &&
 		    ((mac_vid >> ARLTBL_VID_S) & ARLTBL_VID_MASK) != vid)
 			continue;
 		*idx = i;
+		return 0;
 	}
 
+	if (bitmap_weight(free_bins, dev->num_arl_entries) == 0)
+		return -ENOSPC;
+
+	*idx = find_first_bit(free_bins, dev->num_arl_entries);
+
 	return -ENOENT;
 }
 
@@ -1540,10 +1551,21 @@ static int b53_arl_op(struct b53_device *dev, int op, int port,
 	if (op)
 		return ret;
 
-	/* We could not find a matching MAC, so reset to a new entry */
-	if (ret) {
+	switch (ret) {
+	case -ENOSPC:
+		dev_dbg(dev->dev, "{%pM,%.4d} no space left in ARL\n",
+			addr, vid);
+		return is_valid ? ret : 0;
+	case -ENOENT:
+		/* We could not find a matching MAC, so reset to a new entry */
+		dev_dbg(dev->dev, "{%pM,%.4d} not found, using idx: %d\n",
+			addr, vid, idx);
 		fwd_entry = 0;
-		idx = 1;
+		break;
+	default:
+		dev_dbg(dev->dev, "{%pM,%.4d} found, using idx: %d\n",
+			addr, vid, idx);
+		break;
 	}
 
 	/* For multicast address, the port is a bitmask and the validity
diff --git a/drivers/net/dsa/b53/b53_regs.h b/drivers/net/dsa/b53/b53_regs.h
index d914e756cdab..14f617e9173d 100644
--- a/drivers/net/dsa/b53/b53_regs.h
+++ b/drivers/net/dsa/b53/b53_regs.h
@@ -323,6 +323,9 @@
 #define   ARLTBL_STATIC			BIT(15)
 #define   ARLTBL_VALID			BIT(16)
 
+/* Maximum number of bin entries in the ARL for all switches */
+#define B53_ARLTBL_MAX_BIN_ENTRIES	4
+
 /* ARL Search Control Register (8 bit) */
 #define B53_ARL_SRCH_CTL		0x50
 #define B53_ARL_SRCH_CTL_25		0x20
-- 
2.17.1

[PATCH net v2 5/5] net: dsa: b53: b53_arl_rw_op() needs to select IVL or SVL

[Florian Fainelli]

Flip the IVL_SVL_SELECT bit correctly based on the VLAN enable status,
the default is to perform Shared VLAN learning instead of Individual
learning.

Fixes: 1da6df85c6fb ("net: dsa: b53: Implement ARL add/del/dump operations")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 drivers/net/dsa/b53/b53_common.c | 4 ++++
 drivers/net/dsa/b53/b53_regs.h   | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 8cb41583bbad..c283593bef17 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1474,6 +1474,10 @@ static int b53_arl_rw_op(struct b53_device *dev, unsigned int op)
 		reg |= ARLTBL_RW;
 	else
 		reg &= ~ARLTBL_RW;
+	if (dev->vlan_enabled)
+		reg &= ~ARLTBL_IVL_SVL_SELECT;
+	else
+		reg |= ARLTBL_IVL_SVL_SELECT;
 	b53_write8(dev, B53_ARLIO_PAGE, B53_ARLTBL_RW_CTRL, reg);
 
 	return b53_arl_op_wait(dev);
diff --git a/drivers/net/dsa/b53/b53_regs.h b/drivers/net/dsa/b53/b53_regs.h
index 14f617e9173d..c90985c294a2 100644
--- a/drivers/net/dsa/b53/b53_regs.h
+++ b/drivers/net/dsa/b53/b53_regs.h
@@ -292,6 +292,7 @@
 /* ARL Table Read/Write Register (8 bit) */
 #define B53_ARLTBL_RW_CTRL		0x00
 #define    ARLTBL_RW			BIT(0)
+#define    ARLTBL_IVL_SVL_SELECT	BIT(6)
 #define    ARLTBL_START_DONE		BIT(7)
 
 /* MAC Address Index Register (48 bit) */
-- 
2.17.1

Re: [PATCH net v2 0/5] net: dsa: b53: Various ARL fixes

[David Miller]

From: Florian Fainelli <f.fainelli@gmail.com>
Date: Mon, 20 Apr 2020 20:26:50 -0700

> Hi David, Andrew, Vivien, Jakub,
> 
> This patch series fixes a number of short comings in the existing b53
> driver ARL management logic in particular:
> 
> - we were not looking up the {MAC,VID} tuples against their VID, despite
>   having VLANs enabled
> 
> - the MDB entries (multicast) would lose their validity as soon as a
>   single port in the vector would leave the entry
> 
> - the ARL was currently under utilized because we would always place new
>   entries in bin index #1, instead of using all possible bins available,
>   thus reducing the ARL effective size by 50% or 75% depending on the
>   switch generation
> 
> - it was possible to overwrite the ARL entries because no proper space
>   verification was done
> 
> This patch series addresses all of these issues.
> 
> Changes in v2:
> - added a new patch to correctly flip invidual VLAN learning vs. shared
>   VLAN learning depending on the global VLAN state
> 
> - added Andrew's R-b tags for patches which did not change
> 
> - corrected some verbosity and minor issues in patch #4 to match caller
>   expectations, also avoid a variable length DECLARE_BITMAP() call

Series applied and queued up for -stable, thanks.