From 4352b8aee98005853aa63f57d6377282de17a33f Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 23 Aug 2026 13:28:57 -0700 Subject: Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ... --- include/net/dropreason-qdisc.h | 114 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 include/net/dropreason-qdisc.h (limited to 'include/net/dropreason-qdisc.h') diff --git a/include/net/dropreason-qdisc.h b/include/net/dropreason-qdisc.h new file mode 100644 index 000000000..fb151cd31 --- /dev/null +++ b/include/net/dropreason-qdisc.h @@ -0,0 +1,114 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ + +#ifndef _LINUX_DROPREASON_QDISC_H +#define _LINUX_DROPREASON_QDISC_H +#include + +#define DEFINE_QDISC_DROP_REASON(FN, FNe) \ + FN(UNSPEC) \ + FN(GENERIC) \ + FN(OVERLIMIT) \ + FN(CONGESTED) \ + FN(MAXFLOWS) \ + FN(FLOOD_PROTECTION) \ + FN(BAND_LIMIT) \ + FN(HORIZON_LIMIT) \ + FN(FLOW_LIMIT) \ + FN(L4S_STEP_NON_ECN) \ + FNe(MAX) + +#undef FN +#undef FNe +#define FN(reason) QDISC_DROP_##reason, +#define FNe(reason) QDISC_DROP_##reason + +/** + * enum qdisc_drop_reason - reason why a qdisc dropped a packet + * + * Qdisc-specific drop reasons for packet drops that occur within the + * traffic control (TC) queueing discipline layer. These reasons provide + * detailed diagnostics about why packets were dropped by various qdisc + * algorithms, enabling fine-grained monitoring and troubleshooting of + * queue behavior. + */ +enum qdisc_drop_reason { + /** + * @QDISC_DROP_UNSPEC: unspecified/invalid qdisc drop reason. + * Value 0 serves as analogous to SKB_NOT_DROPPED_YET for enum skb_drop_reason. + * Used for catching zero-initialized drop_reason fields. + */ + QDISC_DROP_UNSPEC = 0, + /** + * @__QDISC_DROP_REASON: subsystem base value for qdisc drop reasons + */ + __QDISC_DROP_REASON = SKB_DROP_REASON_SUBSYS_QDISC << + SKB_DROP_REASON_SUBSYS_SHIFT, + /** + * @QDISC_DROP_GENERIC: generic/default qdisc drop, used when no + * more specific reason applies + */ + QDISC_DROP_GENERIC, + /** + * @QDISC_DROP_OVERLIMIT: packet dropped because the qdisc queue + * length exceeded its configured limit (sch->limit). This typically + * indicates the queue is full and cannot accept more packets. + */ + QDISC_DROP_OVERLIMIT, + /** + * @QDISC_DROP_CONGESTED: packet dropped due to active congestion + * control algorithms (e.g., CoDel, PIE, RED) detecting network + * congestion. The qdisc proactively dropped the packet to signal + * congestion to the sender and prevent bufferbloat. + */ + QDISC_DROP_CONGESTED, + /** + * @QDISC_DROP_MAXFLOWS: packet dropped because the qdisc's flow + * tracking table is full and no free slots are available to allocate + * for a new flow. This indicates flow table exhaustion in flow-based + * qdiscs that maintain per-flow state (e.g., SFQ). + */ + QDISC_DROP_MAXFLOWS, + /** + * @QDISC_DROP_FLOOD_PROTECTION: packet dropped by flood protection + * mechanism detecting unresponsive flows (potential DoS/flood). + * Used by qdiscs implementing probabilistic drop algorithms like + * BLUE (e.g., CAKE's Cobalt AQM). + */ + QDISC_DROP_FLOOD_PROTECTION, + /** + * @QDISC_DROP_BAND_LIMIT: packet dropped because the priority band's + * limit was reached. Used by qdiscs with priority bands that have + * per-band packet limits (e.g., FQ). + */ + QDISC_DROP_BAND_LIMIT, + /** + * @QDISC_DROP_HORIZON_LIMIT: packet dropped because its timestamp + * is too far in the future (beyond the configured horizon). + * Used by qdiscs with time-based scheduling (e.g., FQ). + */ + QDISC_DROP_HORIZON_LIMIT, + /** + * @QDISC_DROP_FLOW_LIMIT: packet dropped because an individual flow + * exceeded its per-flow packet/depth limit. Used by FQ and SFQ qdiscs + * to enforce per-flow fairness and prevent a single flow from + * monopolizing queue resources. + */ + QDISC_DROP_FLOW_LIMIT, + /** + * @QDISC_DROP_L4S_STEP_NON_ECN: DualPI2 qdisc dropped a non-ECN-capable + * packet because the L4S queue delay exceeded the step threshold. + * Since the packet cannot be ECN-marked, it must be dropped to signal + * congestion. See RFC 9332 for the DualQ Coupled AQM step mechanism. + */ + QDISC_DROP_L4S_STEP_NON_ECN, + /** + * @QDISC_DROP_MAX: the maximum of qdisc drop reasons, which + * shouldn't be used as a real 'reason' - only for tracing code gen + */ + QDISC_DROP_MAX, +}; + +#undef FN +#undef FNe + +#endif -- cgit v1.3.1