This is a note to let you know that I've just added the patch titled
net: dsa: b53: Rework ARL bin logic
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-dsa-b53-rework-arl-bin-logic.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d36c892b44fc4aad20bdd354d25e88eaff81e07f
Author: Florian Fainelli <f.fainelli@xxxxxxxxx>
Date: Mon Apr 20 20:26:54 2020 -0700
net: dsa: b53: Rework ARL bin logic
[ Upstream commit 6344dbde6a27d10d16246d734b968f84887841e2 ]
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@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index 71525950c641d..060f9b1769298 100644
--- a/drivers/net/dsa/b53/b53_common.c
+++ b/drivers/net/dsa/b53/b53_common.c
@@ -1109,6 +1109,7 @@ 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;
@@ -1116,6 +1117,8 @@ 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;
@@ -1127,13 +1130,21 @@ 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;
*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;
}
@@ -1163,10 +1174,21 @@ 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;
}
memset(&ent, 0, sizeof(ent));
diff --git a/drivers/net/dsa/b53/b53_regs.h b/drivers/net/dsa/b53/b53_regs.h
index 85c44bfba55a2..3cf246c6bdcc4 100644
--- a/drivers/net/dsa/b53/b53_regs.h
+++ b/drivers/net/dsa/b53/b53_regs.h
@@ -280,6 +280,9 @@
#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
