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d4318c1a79
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 <ilpo.jarvinen@linux.intel.com>
Suggested-by: Matthew W Carlis <mattc@purestorage.com>
Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://patch.msgid.link/20251210132907.58799-3-xueshuai@linux.alibaba.com
129 lines
3.4 KiB
C
129 lines
3.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#undef TRACE_SYSTEM
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#define TRACE_SYSTEM pci
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#if !defined(_TRACE_HW_EVENT_PCI_H) || defined(TRACE_HEADER_MULTI_READ)
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#define _TRACE_HW_EVENT_PCI_H
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#include <uapi/linux/pci_regs.h>
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#include <linux/tracepoint.h>
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#define PCI_HOTPLUG_EVENT \
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EM(PCI_HOTPLUG_LINK_UP, "LINK_UP") \
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EM(PCI_HOTPLUG_LINK_DOWN, "LINK_DOWN") \
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EM(PCI_HOTPLUG_CARD_PRESENT, "CARD_PRESENT") \
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EMe(PCI_HOTPLUG_CARD_NOT_PRESENT, "CARD_NOT_PRESENT")
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/* Enums require being exported to userspace, for user tool parsing */
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#undef EM
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#undef EMe
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#define EM(a, b) TRACE_DEFINE_ENUM(a);
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#define EMe(a, b) TRACE_DEFINE_ENUM(a);
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PCI_HOTPLUG_EVENT
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/*
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* Now redefine the EM() and EMe() macros to map the enums to the strings
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* that will be printed in the output.
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*/
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#undef EM
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#undef EMe
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#define EM(a, b) {a, b},
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#define EMe(a, b) {a, b}
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/*
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* Note: For generic PCI hotplug events, we pass already-resolved strings
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* (port_name, slot) instead of driver-specific structures like 'struct
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* controller'. This is because different PCI hotplug drivers (pciehp, cpqphp,
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* ibmphp, shpchp) define their own versions of 'struct controller' with
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* different fields and helper functions. Using driver-specific structures would
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* make the tracepoint interface non-generic and cause compatibility issues
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* across different drivers.
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*/
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TRACE_EVENT(pci_hp_event,
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TP_PROTO(const char *port_name,
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const char *slot,
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const int event),
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TP_ARGS(port_name, slot, event),
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TP_STRUCT__entry(
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__string( port_name, port_name )
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__string( slot, slot )
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__field( int, event )
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),
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TP_fast_assign(
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__assign_str(port_name);
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__assign_str(slot);
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__entry->event = event;
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),
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TP_printk("%s slot:%s, event:%s\n",
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__get_str(port_name),
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__get_str(slot),
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__print_symbolic(__entry->event, PCI_HOTPLUG_EVENT)
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)
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);
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#define PCI_EXP_LNKSTA_LINK_STATUS_MASK (PCI_EXP_LNKSTA_LBMS | \
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PCI_EXP_LNKSTA_LABS | \
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PCI_EXP_LNKSTA_LT | \
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PCI_EXP_LNKSTA_DLLLA)
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#define LNKSTA_FLAGS \
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{ PCI_EXP_LNKSTA_LT, "LT"}, \
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{ PCI_EXP_LNKSTA_DLLLA, "DLLLA"}, \
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{ PCI_EXP_LNKSTA_LBMS, "LBMS"}, \
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{ PCI_EXP_LNKSTA_LABS, "LABS"}
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TRACE_EVENT(pcie_link_event,
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TP_PROTO(struct pci_bus *bus,
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unsigned int reason,
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unsigned int width,
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unsigned int status
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),
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TP_ARGS(bus, reason, width, status),
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TP_STRUCT__entry(
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__string( port_name, pci_name(bus->self))
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__field( unsigned int, type )
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__field( unsigned int, reason )
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__field( unsigned int, cur_bus_speed )
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__field( unsigned int, max_bus_speed )
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__field( unsigned int, width )
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__field( unsigned int, flit_mode )
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__field( unsigned int, link_status )
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),
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TP_fast_assign(
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__assign_str(port_name);
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__entry->type = pci_pcie_type(bus->self);
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__entry->reason = reason;
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__entry->cur_bus_speed = bus->cur_bus_speed;
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__entry->max_bus_speed = bus->max_bus_speed;
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__entry->width = width;
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__entry->flit_mode = bus->flit_mode;
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__entry->link_status = status;
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),
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TP_printk("%s type:%d, reason:%d, cur_bus_speed:%d, max_bus_speed:%d, width:%u, flit_mode:%u, status:%s\n",
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__get_str(port_name),
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__entry->type,
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__entry->reason,
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__entry->cur_bus_speed,
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__entry->max_bus_speed,
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__entry->width,
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__entry->flit_mode,
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__print_flags((unsigned long)__entry->link_status, "|",
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LNKSTA_FLAGS)
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)
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);
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#endif /* _TRACE_HW_EVENT_PCI_H */
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/* This part must be outside protection */
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#include <trace/define_trace.h>
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