[PATCH 6.1 24/83] net: mscc: ocelot: fix incorrect IFH SRC_PORT field in ocelot_ifh_set_basic()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vladimir Oltean <vladimir.oltean@nxp.com>

[ Upstream commit 2d5df3a680ffdaf606baa10636bdb1daf757832e ]

Packets injected by the CPU should have a SRC_PORT field equal to the
CPU port module index in the Analyzer block (ocelot->num_phys_ports).

The blamed commit copied the ocelot_ifh_set_basic() call incorrectly
from ocelot_xmit_common() in net/dsa/tag_ocelot.c. Instead of calling
with "x", it calls with BIT_ULL(x), but the field is not a port mask,
but rather a single port index.

[ side note: this is the technical debt of code duplication :( ]

The error used to be silent and doesn't appear to have other
user-visible manifestations, but with new changes in the packing
library, it now fails loudly as follows:

------------[ cut here ]------------
Cannot store 0x40 inside bits 46-43 - will truncate
sja1105 spi2.0: xmit timed out
WARNING: CPU: 1 PID: 102 at lib/packing.c:98 __pack+0x90/0x198
sja1105 spi2.0: timed out polling for tstamp
CPU: 1 UID: 0 PID: 102 Comm: felix_xmit
Tainted: G        W        N 6.13.0-rc1-00372-gf706b85d972d-dirty #2605
Call trace:
 __pack+0x90/0x198 (P)
 __pack+0x90/0x198 (L)
 packing+0x78/0x98
 ocelot_ifh_set_basic+0x260/0x368
 ocelot_port_inject_frame+0xa8/0x250
 felix_port_deferred_xmit+0x14c/0x258
 kthread_worker_fn+0x134/0x350
 kthread+0x114/0x138

The code path pertains to the ocelot switchdev driver and to the felix
secondary DSA tag protocol, ocelot-8021q. Here seen with ocelot-8021q.

The messenger (packing) is not really to blame, so fix the original
commit instead.

Fixes: e1b9e80236c5 ("net: mscc: ocelot: fix QoS class for injected packets with "ocelot-8021q"")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241212165546.879567-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/mscc/ocelot.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mscc/ocelot.c b/drivers/net/ethernet/mscc/ocelot.c
index 310a36356f56..71dbdac38020 100644
--- a/drivers/net/ethernet/mscc/ocelot.c
+++ b/drivers/net/ethernet/mscc/ocelot.c
@@ -1161,7 +1161,7 @@ void ocelot_ifh_set_basic(void *ifh, struct ocelot *ocelot, int port,
 
 	memset(ifh, 0, OCELOT_TAG_LEN);
 	ocelot_ifh_set_bypass(ifh, 1);
-	ocelot_ifh_set_src(ifh, BIT_ULL(ocelot->num_phys_ports));
+	ocelot_ifh_set_src(ifh, ocelot->num_phys_ports);
 	ocelot_ifh_set_dest(ifh, BIT_ULL(port));
 	ocelot_ifh_set_qos_class(ifh, qos_class);
 	ocelot_ifh_set_tag_type(ifh, tag_type);
-- 
2.39.5