Re: [PATCH v5] PCI: hotplug: Add a generic RAS tracepoint for hotplug event

Shuai Xue
2025-01-14T11:47:41Z

在 2025/1/14 04:55, Steven Rostedt 写道:
> On Thu, 9 Jan 2025 10:55:43 +0800
> Shuai Xue <xueshuai@linux.alibaba.com> wrote:
>
>> diff --git a/drivers/pci/hotplug/trace.h b/drivers/pci/hotplug/trace.h
>> new file mode 100644
>> index 000000000000..5b60cd7bcffb
>> --- /dev/null
>> +++ b/drivers/pci/hotplug/trace.h
>> @@ -0,0 +1,68 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +#if !defined(_TRACE_HW_EVENT_PCI_HP_H) || defined(TRACE_HEADER_MULTI_READ)
>> +#define _TRACE_HW_EVENT_PCI_HP_H
>> +
>> +#include <linux/tracepoint.h>
>> +
>> +#undef TRACE_SYSTEM
>> +#define TRACE_SYSTEM pci
>> +
>> +#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")
>
> Since you are creating these enums in this patch, you can also do a
> shortcut here too. Instead of doing the define here, move it to
> include/uapi/linux/pci.h:
>
>> +
>> +/* 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}
>> +
>> +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_HP_H */
>> +
>> +#undef TRACE_INCLUDE_PATH
>> +#define TRACE_INCLUDE_PATH ../../drivers/pci/hotplug
>> +#undef TRACE_INCLUDE_FILE
>> +#define TRACE_INCLUDE_FILE trace
>> +
>> +/* This part must be outside protection */
>> +#include <trace/define_trace.h>
>> diff --git a/include/uapi/linux/pci.h b/include/uapi/linux/pci.h
>> index a769eefc5139..4f150028965d 100644
>> --- a/include/uapi/linux/pci.h
>> +++ b/include/uapi/linux/pci.h
>> @@ -39,4 +39,11 @@
>> #define PCIIOC_MMAP_IS_MEM (PCIIOC_BASE | 0x02) /* Set mmap state to MEM space. */
>> #define PCIIOC_WRITE_COMBINE (PCIIOC_BASE | 0x03) /* Enable/disable write-combining. */
>>
>> +enum pci_hotplug_event {
>> + PCI_HOTPLUG_LINK_UP,
>> + PCI_HOTPLUG_LINK_DOWN,
>> + PCI_HOTPLUG_CARD_PRESENT,
>> + PCI_HOTPLUG_CARD_NOT_PRESENT,
>> +};
>
> Instead of defining the enum as you did above, if you have the define of
> the enums here, you could do:
>
> #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")
>
> #undef EM
> #undef EMe
> #define EM(a, b) a,
> #define EMe(a, b) a,
>
> enum pci_hotplug_event {
> PCI_HOTPLUG_EVENT
> };
>
> Then you only have one place to worry about adding new enums ;-)

Will do.

>
> -- Steve
>

Thanks for valuable comments.

Best Regards,
Shuai