在 2025/6/12 18:31, Manivannan Sadhasivam 写道:

On Mon, Feb 17, 2025 at 10:42:17AM +0800, Shuai Xue wrote:

quoted

The current implementation of pcie_do_recovery() assumes that the
recovery process is executed on the device that detected the error.

s/on/for

quoted

However, the DPC driver currently passes the error port that experienced
the DPC event to pcie_do_recovery().

Use the SOURCE ID register to correctly identify the device that
detected the error. When passing the error device, the
pcie_do_recovery() will find the upstream bridge and walk bridges
potentially AER affected. And subsequent patches will be able to

s/patches/commits

Will fix the typos.

quoted

accurately access AER status of the error device.

Should not observe any functional changes.

Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
---
  drivers/pci/pci.h      |  2 +-
  drivers/pci/pcie/dpc.c | 28 ++++++++++++++++++++++++----
  drivers/pci/pcie/edr.c |  7 ++++---
  3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 01e51db8d285..870d2fbd6ff2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h

@@ -572,7 +572,7 @@ struct rcec_ea {
  void pci_save_dpc_state(struct pci_dev *dev);
  void pci_restore_dpc_state(struct pci_dev *dev);
  void pci_dpc_init(struct pci_dev *pdev);
-void dpc_process_error(struct pci_dev *pdev);
+struct pci_dev *dpc_process_error(struct pci_dev *pdev);
  pci_ers_result_t dpc_reset_link(struct pci_dev *pdev);
  bool pci_dpc_recovered(struct pci_dev *pdev);
  unsigned int dpc_tlp_log_len(struct pci_dev *dev);

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 1a54a0b657ae..ea3ea989afa7 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c

@@ -253,10 +253,20 @@ static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev,
  	return 1;
  }
  
-void dpc_process_error(struct pci_dev *pdev)
+/**
+ * dpc_process_error - handle the DPC error status
+ * @pdev: the port that experienced the containment event
+ *
+ * Return the device that detected the error.

s/Return/Return:

quoted

+ *
+ * NOTE: The device reference count is increased, the caller must decrement
+ * the reference count by calling pci_dev_put().
+ */
+struct pci_dev *dpc_process_error(struct pci_dev *pdev)
  {
  	u16 cap = pdev->dpc_cap, status, source, reason, ext_reason;
  	struct aer_err_info info;
+	struct pci_dev *err_dev;
  
  	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
  	pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source);

@@ -279,6 +289,13 @@ void dpc_process_error(struct pci_dev *pdev)
  		 "software trigger" :
  		 "reserved error");
  
+	if (reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_NFE ||
+	    reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_FE)
+		err_dev = pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+					    PCI_BUS_NUM(source), source & 0xff);
+	else
+		err_dev = pci_dev_get(pdev);
+
  	/* show RP PIO error detail information */
  	if (pdev->dpc_rp_extensions &&
  	    reason == PCI_EXP_DPC_STATUS_TRIGGER_RSN_IN_EXT &&

@@ -291,6 +308,8 @@ void dpc_process_error(struct pci_dev *pdev)
  		pci_aer_clear_nonfatal_status(pdev);
  		pci_aer_clear_fatal_status(pdev);
  	}
+
+	return err_dev;
  }
  
  static void pci_clear_surpdn_errors(struct pci_dev *pdev)

@@ -346,7 +365,7 @@ static bool dpc_is_surprise_removal(struct pci_dev *pdev)
  
  static irqreturn_t dpc_handler(int irq, void *context)
  {
-	struct pci_dev *err_port = context;
+	struct pci_dev *err_port = context, *err_dev;
  
  	/*
  	 * According to PCIe r6.0 sec 6.7.6, errors are an expected side effect

@@ -357,10 +376,11 @@ static irqreturn_t dpc_handler(int irq, void *context)
  		return IRQ_HANDLED;
  	}
  
-	dpc_process_error(err_port);
+	err_dev = dpc_process_error(err_port);
  
  	/* We configure DPC so it only triggers on ERR_FATAL */
-	pcie_do_recovery(err_port, pci_channel_io_frozen, dpc_reset_link);
+	pcie_do_recovery(err_dev, pci_channel_io_frozen, dpc_reset_link);
+	pci_dev_put(err_dev);
  
  	return IRQ_HANDLED;
  }

diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c
index 521fca2f40cb..088f3e188f54 100644
--- a/drivers/pci/pcie/edr.c
+++ b/drivers/pci/pcie/edr.c

@@ -150,7 +150,7 @@ static int acpi_send_edr_status(struct pci_dev *pdev, struct pci_dev *edev,
  
  static void edr_handle_event(acpi_handle handle, u32 event, void *data)
  {
-	struct pci_dev *pdev = data, *err_port;
+	struct pci_dev *pdev = data, *err_port, *err_dev;
  	pci_ers_result_t estate = PCI_ERS_RESULT_DISCONNECT;
  	u16 status;
  

@@ -190,7 +190,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
  		goto send_ost;
  	}
  
-	dpc_process_error(err_port);
+	err_dev = dpc_process_error(err_port);
  	pci_aer_raw_clear_status(err_port);
  
  	/*

@@ -198,7 +198,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
  	 * or ERR_NONFATAL, since the link is already down, use the FATAL
  	 * error recovery path for both cases.
  	 */
-	estate = pcie_do_recovery(err_port, pci_channel_io_frozen, dpc_reset_link);
+	estate = pcie_do_recovery(err_dev, pci_channel_io_frozen, dpc_reset_link);
  
  send_ost:
  

@@ -216,6 +216,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
  	}
  
  	pci_dev_put(err_port);
+	pci_dev_put(err_dev);

err_dev is not a valid pointer before calling dpc_process_error(). So either
initialize it with NULL or only call it in error paths after
dpc_process_error().

And btw, pci_dev_put(err_dev) should come before pci_dev_put(err_port).

- Mani

You are right.

Will send a new patch to fix it.

Thanks.
Shuai