From 9e541b3cee70a3bbe86b176c903c23b29fe033cd Mon Sep 17 00:00:00 2001 From: Shuai Xue Date: Wed, 10 Dec 2025 21:29:05 +0800 Subject: PCI: trace: Add generic RAS tracepoint for hotplug event MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hotplug events are critical indicators for analyzing hardware health, and surprise link downs can significantly impact system performance and reliability. Define a new TRACING_SYSTEM named "pci", add a generic RAS tracepoint for hotplug event to help health checks. Add enum pci_hotplug_event in include/uapi/linux/pci.h so applications like rasdaemon can register tracepoint event handlers for it. The following output is generated when a device is hotplugged: $ echo 1 > /sys/kernel/debug/tracing/events/pci/pci_hp_event/enable $ cat /sys/kernel/debug/tracing/trace_pipe irq/51-pciehp-88 [001] ..... 1311.177459: pci_hp_event: 0000:00:02.0 slot:10, event:CARD_PRESENT irq/51-pciehp-88 [001] ..... 1311.177566: pci_hp_event: 0000:00:02.0 slot:10, event:LINK_UP Suggested-by: Lukas Wunner Signed-off-by: Shuai Xue Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Reviewed-by: Jonathan Cameron Reviewed-by: Steven Rostedt (Google) # for trace event Reviewed-by: Ilpo Järvinen Link: https://patch.msgid.link/20251210132907.58799-2-xueshuai@linux.alibaba.com --- include/trace/events/pci.h | 72 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 include/trace/events/pci.h (limited to 'include/trace') diff --git a/include/trace/events/pci.h b/include/trace/events/pci.h new file mode 100644 index 000000000000..39e512a167ee --- /dev/null +++ b/include/trace/events/pci.h @@ -0,0 +1,72 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM pci + +#if !defined(_TRACE_HW_EVENT_PCI_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_HW_EVENT_PCI_H + +#include + +#define PCI_HOTPLUG_EVENT \ + EM(PCI_HOTPLUG_LINK_UP, "LINK_UP") \ + EM(PCI_HOTPLUG_LINK_DOWN, "LINK_DOWN") \ + EM(PCI_HOTPLUG_CARD_PRESENT, "CARD_PRESENT") \ + EMe(PCI_HOTPLUG_CARD_NOT_PRESENT, "CARD_NOT_PRESENT") + +/* Enums require being exported to userspace, for user tool parsing */ +#undef EM +#undef EMe +#define EM(a, b) TRACE_DEFINE_ENUM(a); +#define EMe(a, b) TRACE_DEFINE_ENUM(a); + +PCI_HOTPLUG_EVENT + +/* + * Now redefine the EM() and EMe() macros to map the enums to the strings + * that will be printed in the output. + */ +#undef EM +#undef EMe +#define EM(a, b) {a, b}, +#define EMe(a, b) {a, b} + +/* + * Note: For generic PCI hotplug events, we pass already-resolved strings + * (port_name, slot) instead of driver-specific structures like 'struct + * controller'. This is because different PCI hotplug drivers (pciehp, cpqphp, + * ibmphp, shpchp) define their own versions of 'struct controller' with + * different fields and helper functions. Using driver-specific structures would + * make the tracepoint interface non-generic and cause compatibility issues + * across different drivers. + */ +TRACE_EVENT(pci_hp_event, + + TP_PROTO(const char *port_name, + const char *slot, + const int event), + + TP_ARGS(port_name, slot, event), + + TP_STRUCT__entry( + __string( port_name, port_name ) + __string( slot, slot ) + __field( int, event ) + ), + + TP_fast_assign( + __assign_str(port_name); + __assign_str(slot); + __entry->event = event; + ), + + TP_printk("%s slot:%s, event:%s\n", + __get_str(port_name), + __get_str(slot), + __print_symbolic(__entry->event, PCI_HOTPLUG_EVENT) + ) +); + +#endif /* _TRACE_HW_EVENT_PCI_H */ + +/* This part must be outside protection */ +#include -- cgit v1.2.3 From d4318c1a79ac49f0726dd23a01d1961757b5f98d Mon Sep 17 00:00:00 2001 From: Shuai Xue Date: Wed, 10 Dec 2025 21:29:06 +0800 Subject: PCI: trace: Add RAS tracepoint to monitor link speed changes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PCIe link speed degradation directly impacts system performance and often indicates hardware issues such as faulty devices, physical layer problems, or configuration errors. To this end, add a RAS tracepoint to monitor link speed changes, enabling proactive health checks and diagnostic analysis. The following output is generated when a device is hotplugged: $ echo 1 > /sys/kernel/debug/tracing/events/pci/pcie_link_event/enable $ cat /sys/kernel/debug/tracing/trace_pipe irq/51-pciehp-88 [001] ..... 381.545386: pcie_link_event: 0000:00:02.0 type:4, reason:4, cur_bus_speed:20, max_bus_speed:23, width:1, flit_mode:0, status:DLLLA Suggested-by: Ilpo Järvinen Suggested-by: Matthew W Carlis Suggested-by: Lukas Wunner Signed-off-by: Shuai Xue Signed-off-by: Bjorn Helgaas Reviewed-by: Ilpo Järvinen Link: https://patch.msgid.link/20251210132907.58799-3-xueshuai@linux.alibaba.com --- include/trace/events/pci.h | 57 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) (limited to 'include/trace') diff --git a/include/trace/events/pci.h b/include/trace/events/pci.h index 39e512a167ee..9a9122f62fd3 100644 --- a/include/trace/events/pci.h +++ b/include/trace/events/pci.h @@ -5,6 +5,7 @@ #if !defined(_TRACE_HW_EVENT_PCI_H) || defined(TRACE_HEADER_MULTI_READ) #define _TRACE_HW_EVENT_PCI_H +#include #include #define PCI_HOTPLUG_EVENT \ @@ -66,6 +67,62 @@ TRACE_EVENT(pci_hp_event, ) ); +#define PCI_EXP_LNKSTA_LINK_STATUS_MASK (PCI_EXP_LNKSTA_LBMS | \ + PCI_EXP_LNKSTA_LABS | \ + PCI_EXP_LNKSTA_LT | \ + PCI_EXP_LNKSTA_DLLLA) + +#define LNKSTA_FLAGS \ + { PCI_EXP_LNKSTA_LT, "LT"}, \ + { PCI_EXP_LNKSTA_DLLLA, "DLLLA"}, \ + { PCI_EXP_LNKSTA_LBMS, "LBMS"}, \ + { PCI_EXP_LNKSTA_LABS, "LABS"} + +TRACE_EVENT(pcie_link_event, + + TP_PROTO(struct pci_bus *bus, + unsigned int reason, + unsigned int width, + unsigned int status + ), + + TP_ARGS(bus, reason, width, status), + + TP_STRUCT__entry( + __string( port_name, pci_name(bus->self)) + __field( unsigned int, type ) + __field( unsigned int, reason ) + __field( unsigned int, cur_bus_speed ) + __field( unsigned int, max_bus_speed ) + __field( unsigned int, width ) + __field( unsigned int, flit_mode ) + __field( unsigned int, link_status ) + ), + + TP_fast_assign( + __assign_str(port_name); + __entry->type = pci_pcie_type(bus->self); + __entry->reason = reason; + __entry->cur_bus_speed = bus->cur_bus_speed; + __entry->max_bus_speed = bus->max_bus_speed; + __entry->width = width; + __entry->flit_mode = bus->flit_mode; + __entry->link_status = status; + ), + + TP_printk("%s type:%d, reason:%d, cur_bus_speed:%d, max_bus_speed:%d, width:%u, flit_mode:%u, status:%s\n", + __get_str(port_name), + __entry->type, + __entry->reason, + __entry->cur_bus_speed, + __entry->max_bus_speed, + __entry->width, + __entry->flit_mode, + __print_flags((unsigned long)__entry->link_status, "|", + LNKSTA_FLAGS) + ) +); + #endif /* _TRACE_HW_EVENT_PCI_H */ /* This part must be outside protection */ -- cgit v1.2.3