diff mbox series

[v3,net,2/2] net: enetc: Do not configure preemptible TCs if SIs do not support

Message ID 20241125090719.2159124-3-wei.fang@nxp.com (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series fix crash issue when setting MQPRIO for VFs | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3 this patch: 3
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 blamed authors not CCed: horms@kernel.org; 1 maintainers not CCed: horms@kernel.org
netdev/build_clang success Errors and warnings before: 3 this patch: 3
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 5 this patch: 5
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest pending net-next-2024-11-25--12-00 (tests: 0)

Commit Message

Wei Fang Nov. 25, 2024, 9:07 a.m. UTC
Both ENETC PF and VF drivers share enetc_setup_tc_mqprio() to configure
MQPRIO. And enetc_setup_tc_mqprio() calls enetc_change_preemptible_tcs()
to configure preemptible TCs. However, only PF is able to configure
preemptible TCs. Because only PF has related registers, while VF does not
have these registers. So for VF, its hw->port pointer is NULL. Therefore,
VF will access an invalid pointer when accessing a non-existent register,
which will cause a crash issue. The simplified log is as follows.

root@ls1028ardb:~# tc qdisc add dev eno0vf0 parent root handle 100: \
mqprio num_tc 4 map 0 0 1 1 2 2 3 3 queues 1@0 1@1 1@2 1@3 hw 1
[  187.290775] Unable to handle kernel paging request at virtual address 0000000000001f00
[  187.424831] pc : enetc_mm_commit_preemptible_tcs+0x1c4/0x400
[  187.430518] lr : enetc_mm_commit_preemptible_tcs+0x30c/0x400
[  187.511140] Call trace:
[  187.513588]  enetc_mm_commit_preemptible_tcs+0x1c4/0x400
[  187.518918]  enetc_setup_tc_mqprio+0x180/0x214
[  187.523374]  enetc_vf_setup_tc+0x1c/0x30
[  187.527306]  mqprio_enable_offload+0x144/0x178
[  187.531766]  mqprio_init+0x3ec/0x668
[  187.535351]  qdisc_create+0x15c/0x488
[  187.539023]  tc_modify_qdisc+0x398/0x73c
[  187.542958]  rtnetlink_rcv_msg+0x128/0x378
[  187.547064]  netlink_rcv_skb+0x60/0x130
[  187.550910]  rtnetlink_rcv+0x18/0x24
[  187.554492]  netlink_unicast+0x300/0x36c
[  187.558425]  netlink_sendmsg+0x1a8/0x420
[  187.606759] ---[ end trace 0000000000000000 ]---

In addition, some PFs also do not support configuring preemptible TCs,
such as eno1 and eno3 on LS1028A. It won't crash like it does for VFs,
but we should prevent these PFs from accessing these unimplemented
registers.

Fixes: 827145392a4a ("net: enetc: only commit preemptible TCs to hardware when MM TX is active")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Suggested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
v2 changes:
1. Change the title and refine the commit message
2. Only set ENETC_SI_F_QBU bit for PFs which support Qbu
3. Prevent all SIs which not support Qbu from configuring preemptible
TCs
v3 changes:
1. remove the changes in enetc_get_si_caps().
---
 drivers/net/ethernet/freescale/enetc/enetc.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index bece220535a1..535969fa0fdb 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -29,6 +29,9 @@  EXPORT_SYMBOL_GPL(enetc_port_mac_wr);
 static void enetc_change_preemptible_tcs(struct enetc_ndev_priv *priv,
 					 u8 preemptible_tcs)
 {
+	if (!(priv->si->hw_features & ENETC_SI_F_QBU))
+		return;
+
 	priv->preemptible_tcs = preemptible_tcs;
 	enetc_mm_commit_preemptible_tcs(priv);
 }