diff mbox series

[net,3/5] net: lan966x: Fix usage of lan966x->mac_lock when entry is removed

Message ID 20220714194040.231651-4-horatiu.vultur@microchip.com (mailing list archive)
State Accepted
Commit 99343cfa4f7560abf933fff7ab3ea58a6905c917
Delegated to: Netdev Maintainers
Headers show
Series net: lan966x: Fix issues with MAC table | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 7 of 7 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 37 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Horatiu Vultur July 14, 2022, 7:40 p.m. UTC
To remove an entry to the MAC table, it is required first to setup the
entry and then issue a command for the MAC to forget the entry.
So if it happens for two threads to remove simultaneously an entry
in MAC table then it would be a race condition.
Fix this by using lan966x->mac_lock to protect the HW access.

Fixes: e18aba8941b40 ("net: lan966x: add mactable support")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 .../ethernet/microchip/lan966x/lan966x_mac.c  | 24 +++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c b/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c
index 4f8fd5cde950..d0b8eba0a66d 100644
--- a/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c
+++ b/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c
@@ -119,11 +119,13 @@  int lan966x_mac_learn(struct lan966x *lan966x, int port,
 	return __lan966x_mac_learn(lan966x, port, false, mac, vid, type);
 }
 
-int lan966x_mac_forget(struct lan966x *lan966x,
-		       const unsigned char mac[ETH_ALEN],
-		       unsigned int vid,
-		       enum macaccess_entry_type type)
+static int lan966x_mac_forget_locked(struct lan966x *lan966x,
+				     const unsigned char mac[ETH_ALEN],
+				     unsigned int vid,
+				     enum macaccess_entry_type type)
 {
+	lockdep_assert_held(&lan966x->mac_lock);
+
 	lan966x_mac_select(lan966x, mac, vid);
 
 	/* Issue a forget command */
@@ -134,6 +136,20 @@  int lan966x_mac_forget(struct lan966x *lan966x,
 	return lan966x_mac_wait_for_completion(lan966x);
 }
 
+int lan966x_mac_forget(struct lan966x *lan966x,
+		       const unsigned char mac[ETH_ALEN],
+		       unsigned int vid,
+		       enum macaccess_entry_type type)
+{
+	int ret;
+
+	spin_lock(&lan966x->mac_lock);
+	ret = lan966x_mac_forget_locked(lan966x, mac, vid, type);
+	spin_unlock(&lan966x->mac_lock);
+
+	return ret;
+}
+
 int lan966x_mac_cpu_learn(struct lan966x *lan966x, const char *addr, u16 vid)
 {
 	return lan966x_mac_learn(lan966x, PGID_CPU, addr, vid, ENTRYTYPE_LOCKED);