From nobody Mon Feb 9 14:32:56 2026 Received: from out30-101.freemail.mail.aliyun.com (out30-101.freemail.mail.aliyun.com [115.124.30.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F12221D516C; Sat, 25 Oct 2025 11:42:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.101 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761392544; cv=none; b=e0JDq5i9qE5HUpLAYqsBk2TktptsQ+8ic8pJSAp3RfzIuQ4ISkMNFTYOYxfW2P+LCr3yqf73K7x1yP/Ul1tFSm/AIRQwmrIyQPNfGh77l1nwGlgE1XpJ8yhxCbT+oIATw/DWvbT+oRqZAES7twQHP5rkuJWmgZHKJ0RhVA3ceI4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761392544; c=relaxed/simple; bh=4GpavlZCK7jfW+tbgBCh97zrQasfjN1Irb4roaVDKN4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=O23h6/pIeGzqdinrqqZCpwGrJUtpmJALh4KXvloXolBDUekhLPN7mtaF5yDFSvKkVjbCeP8J1zHLy4wqLsahx/zyJ0fs5ivgIJ3zfnSstQ9QG1IoJv1rwChQZD25IWvG9u8ZtoKLoN6/Qrn1Lj422sOoDRcnIa1v27n2HmVmnkc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=Au+GUjnI; arc=none smtp.client-ip=115.124.30.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="Au+GUjnI" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1761392528; h=From:To:Subject:Date:Message-Id:MIME-Version:Content-Type; bh=daBDsIEoo7d0DXzD96pe4JGjDFJicmWft6qR8RVDeNU=; b=Au+GUjnIhRk4Nbrko7T2QCps8MCyvFwrtpNeyQYnmUNbq5q8muwGRDzgKEdnJBnj1y9piOUkA38B3Z1V5t5Cl3KeWN80m5Y6oIFZFsxMePQU2i2nNdrrBbIFzCY7VU2q6KrsbcTdruNq7if9jxibHAm2pVz+YUEuV3Yp0VvDWG0= Received: from localhost.localdomain(mailfrom:xueshuai@linux.alibaba.com fp:SMTPD_---0WqwoUgY_1761392525 cluster:ay36) by smtp.aliyun-inc.com; Sat, 25 Oct 2025 19:42:06 +0800 From: Shuai Xue To: rostedt@goodmis.org, lukas@wunner.de, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, linux-trace-kernel@vger.kernel.org, helgaas@kernel.org, ilpo.jarvinen@linux.intel.com, mattc@purestorage.com, Jonathan.Cameron@huawei.com Cc: bhelgaas@google.com, tony.luck@intel.com, bp@alien8.de, xueshuai@linux.alibaba.com, mhiramat@kernel.org, mathieu.desnoyers@efficios.com, oleg@redhat.com, naveen@kernel.org, davem@davemloft.net, anil.s.keshavamurthy@intel.com, mark.rutland@arm.com, peterz@infradead.org, tianruidong@linux.alibaba.com Subject: [PATCH v13 1/3] PCI: trace: Add a generic RAS tracepoint for hotplug event Date: Sat, 25 Oct 2025 19:41:56 +0800 Message-Id: <20251025114158.71714-2-xueshuai@linux.alibaba.com> X-Mailer: git-send-email 2.39.5 (Apple Git-154) In-Reply-To: <20251025114158.71714-1-xueshuai@linux.alibaba.com> References: <20251025114158.71714-1-xueshuai@linux.alibaba.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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 Reviewed-by: Lukas Wunner Reviewed-by: Jonathan Cameron Reviewed-by: "Steven Rostedt (Google)" # for trace ev= ent Reviewed-by: Ilpo J=C3=A4rvinen Signed-off-by: Shuai Xue --- drivers/pci/Makefile | 3 ++ drivers/pci/hotplug/pciehp_ctrl.c | 31 ++++++++++--- drivers/pci/trace.c | 11 +++++ include/trace/events/pci.h | 72 +++++++++++++++++++++++++++++++ include/uapi/linux/pci.h | 7 +++ 5 files changed, 118 insertions(+), 6 deletions(-) create mode 100644 drivers/pci/trace.c create mode 100644 include/trace/events/pci.h diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile index 67647f1880fb..58a4e4ea76b0 100644 --- a/drivers/pci/Makefile +++ b/drivers/pci/Makefile @@ -45,3 +45,6 @@ obj-y +=3D controller/ obj-y +=3D switch/ =20 subdir-ccflags-$(CONFIG_PCI_DEBUG) :=3D -DDEBUG + +CFLAGS_trace.o :=3D -I$(src) +obj-$(CONFIG_TRACING) +=3D trace.o diff --git a/drivers/pci/hotplug/pciehp_ctrl.c b/drivers/pci/hotplug/pciehp= _ctrl.c index bcc938d4420f..7805f697a02c 100644 --- a/drivers/pci/hotplug/pciehp_ctrl.c +++ b/drivers/pci/hotplug/pciehp_ctrl.c @@ -19,6 +19,7 @@ #include #include #include +#include =20 #include "../pci.h" #include "pciehp.h" @@ -244,12 +245,20 @@ void pciehp_handle_presence_or_link_change(struct con= troller *ctrl, u32 events) case ON_STATE: ctrl->state =3D POWEROFF_STATE; mutex_unlock(&ctrl->state_lock); - if (events & PCI_EXP_SLTSTA_DLLSC) + if (events & PCI_EXP_SLTSTA_DLLSC) { ctrl_info(ctrl, "Slot(%s): Link Down\n", slot_name(ctrl)); - if (events & PCI_EXP_SLTSTA_PDC) + trace_pci_hp_event(pci_name(ctrl->pcie->port), + slot_name(ctrl), + PCI_HOTPLUG_LINK_DOWN); + } + if (events & PCI_EXP_SLTSTA_PDC) { ctrl_info(ctrl, "Slot(%s): Card not present\n", slot_name(ctrl)); + trace_pci_hp_event(pci_name(ctrl->pcie->port), + slot_name(ctrl), + PCI_HOTPLUG_CARD_NOT_PRESENT); + } pciehp_disable_slot(ctrl, SURPRISE_REMOVAL); break; default: @@ -269,6 +278,9 @@ void pciehp_handle_presence_or_link_change(struct contr= oller *ctrl, u32 events) INDICATOR_NOOP); ctrl_info(ctrl, "Slot(%s): Card not present\n", slot_name(ctrl)); + trace_pci_hp_event(pci_name(ctrl->pcie->port), + slot_name(ctrl), + PCI_HOTPLUG_CARD_NOT_PRESENT); } mutex_unlock(&ctrl->state_lock); return; @@ -281,12 +293,19 @@ void pciehp_handle_presence_or_link_change(struct con= troller *ctrl, u32 events) case OFF_STATE: ctrl->state =3D POWERON_STATE; mutex_unlock(&ctrl->state_lock); - if (present) + if (present) { ctrl_info(ctrl, "Slot(%s): Card present\n", slot_name(ctrl)); - if (link_active) - ctrl_info(ctrl, "Slot(%s): Link Up\n", - slot_name(ctrl)); + trace_pci_hp_event(pci_name(ctrl->pcie->port), + slot_name(ctrl), + PCI_HOTPLUG_CARD_PRESENT); + } + if (link_active) { + ctrl_info(ctrl, "Slot(%s): Link Up\n", slot_name(ctrl)); + trace_pci_hp_event(pci_name(ctrl->pcie->port), + slot_name(ctrl), + PCI_HOTPLUG_LINK_UP); + } ctrl->request_result =3D pciehp_enable_slot(ctrl); break; default: diff --git a/drivers/pci/trace.c b/drivers/pci/trace.c new file mode 100644 index 000000000000..cf11abca8602 --- /dev/null +++ b/drivers/pci/trace.c @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Tracepoints for PCI system + * + * Copyright (C) 2025 Alibaba Corporation + */ + +#include + +#define CREATE_TRACE_POINTS +#include 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, cp= qphp, + * 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 =3D 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 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 s= pace. */ #define PCIIOC_WRITE_COMBINE (PCIIOC_BASE | 0x03) /* Enable/disable write-= combining. */ =20 +enum pci_hotplug_event { + PCI_HOTPLUG_LINK_UP, + PCI_HOTPLUG_LINK_DOWN, + PCI_HOTPLUG_CARD_PRESENT, + PCI_HOTPLUG_CARD_NOT_PRESENT, +}; + #endif /* _UAPILINUX_PCI_H */ --=20 2.39.3