Merge branch 'improve-the-taprio-qdisc-s-relationship-with-its-children'

Vladimir Oltean says:

====================
Improve the taprio qdisc's relationship with its children

v1: https://lore.kernel.org/lkml/20230531173928.1942027-1-vladimir.oltean@nxp.com/

Prompted by Vinicius' request to consolidate some child Qdisc
dereferences in taprio:
https://lore.kernel.org/netdev/87edmxv7x2.fsf@intel.com/

I remembered that I had left some unfinished work in this Qdisc, namely
commit af7b29b1deaa ("Revert "net/sched: taprio: make qdisc_leaf() see
the per-netdev-queue pfifo child qdiscs"").

This patch set represents another stab at, essentially, what's in the
title. Not only does taprio not properly detect when it's grafted as a
non-root qdisc, but it also returns incorrect per-class stats.
Eventually, Vinicius' request is addressed too, although in a different
form than the one he requested (which was purely cosmetic).

Review from people more experienced with Qdiscs than me would be
appreciated. I tried my best to explain what I consider to be problems.
I am deliberately targeting net-next because the changes are too
invasive for net - they were reverted from stable once already.
====================

Link: https://lore.kernel.org/r/20230807193324.4128292-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/include/linux/ptp_mock.h b/include/linux/ptp_mock.h
new file mode 100644
index 000000000000..72eb401034d9
--- /dev/null
+++ b/include/linux/ptp_mock.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Mock-up PTP Hardware Clock driver for virtual network devices
+ *
+ * Copyright 2023 NXP
+ */
+
+#ifndef _PTP_MOCK_H_
+#define _PTP_MOCK_H_
+
+struct device;
+struct mock_phc;
+
+#if IS_ENABLED(CONFIG_PTP_1588_CLOCK_MOCK)
+
+struct mock_phc *mock_phc_create(struct device *dev);
+void mock_phc_destroy(struct mock_phc *phc);
+int mock_phc_index(struct mock_phc *phc);
+
+#else
+
+static inline struct mock_phc *mock_phc_create(struct device *dev)
+{
+	return NULL;
+}
+
+static inline void mock_phc_destroy(struct mock_phc *phc)
+{
+}
+
+static inline int mock_phc_index(struct mock_phc *phc)
+{
+	return -1;
+}
+
+#endif
+
+#endif /* _PTP_MOCK_H_ */