[RFC PATCH 6/9] PCI: Add 'rcec' field to pci_dev for associated RCiEPs

[Sean V Kelley <sean.v.kelley@xxxxxxxxx>]

From: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>

When attempting error recovery for an RCiEP associated with an RCEC device,
there needs to be a way to update the Root Error Status, the Uncorrectable
Error Status and the Uncorrectable Error Severity of the parent RCEC.
So add the 'rcec' field to the pci_dev structure and provide a hook for the
Root Port Driver to associate RCiEPs with their respective parent RCEC.

Co-developed-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@xxxxxxxxx>
Signed-off-by: Sean V Kelley <sean.v.kelley@xxxxxxxxx>
---
 drivers/pci/pcie/aer.c         |  9 +++++----
 drivers/pci/pcie/err.c         |  9 +++++++++
 drivers/pci/pcie/portdrv_pci.c | 15 +++++++++++++++
 include/linux/pci.h            |  3 +++
 4 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 3acf56683915..f1bf06be449e 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1335,17 +1335,18 @@ static int aer_probe(struct pcie_device *dev)
 static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 {
 	int aer = dev->aer_cap;
+	int rc = 0;
 	u32 reg32;
-	int rc;
-
 
 	/* Disable Root's interrupt in response to error messages */
 	pci_read_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, &reg32);
 	reg32 &= ~ROOT_PORT_INTR_ON_MESG_MASK;
 	pci_write_config_dword(dev, aer + PCI_ERR_ROOT_COMMAND, reg32);
 
-	rc = pci_bus_error_reset(dev);
-	pci_info(dev, "Root Port link has been reset\n");
+	if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC) {
+		rc = pci_bus_error_reset(dev);
+		pci_info(dev, "Root Port link has been reset\n");
+	}
 
 	/* Clear Root Error Status */
 	pci_read_config_dword(dev, aer + PCI_ERR_ROOT_STATUS, &reg32);
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 9b3ec94bdf1d..0aae7643132e 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -203,6 +203,11 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 		pci_walk_dev_affected(dev, report_frozen_detected, &status);
 		if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
 			status = flr_on_rciep(dev);
+			/*
+			 * The callback only clears the Root Error Status
+			 * of the RCEC (see aer.c).
+			 */
+			reset_link(dev->rcec);
 			if (status != PCI_ERS_RESULT_RECOVERED) {
 				pci_warn(dev, "function level reset failed\n");
 				goto failed;
@@ -246,7 +251,11 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
 	     pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC)) {
 		pci_aer_clear_device_status(dev);
 		pci_aer_clear_nonfatal_status(dev);
+	} else if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) {
+		pci_aer_clear_device_status(dev->rcec);
+		pci_aer_clear_nonfatal_status(dev->rcec);
 	}
+
 	pci_info(dev, "device recovery successful\n");
 	return status;
 
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index d5b109499b10..f9409a0110c2 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -90,6 +90,18 @@ static const struct dev_pm_ops pcie_portdrv_pm_ops = {
 #define PCIE_PORTDRV_PM_OPS	NULL
 #endif /* !PM */
 
+static int pcie_hook_rcec(struct pci_dev *pdev, void *data)
+{
+	struct pci_dev *rcec = (struct pci_dev *)data;
+
+	pdev->rcec = rcec;
+	pci_info(rcec, "RCiEP(under an RCEC) %04x:%02x:%02x.%d\n",
+		 pci_domain_nr(pdev->bus), pdev->bus->number,
+		 PCI_SLOT(pdev->devfn), PCI_FUNC(pdev->devfn));
+
+	return 0;
+}
+
 /*
  * pcie_portdrv_probe - Probe PCI-Express port devices
  * @dev: PCI-Express port device being probed
@@ -110,6 +122,9 @@ static int pcie_portdrv_probe(struct pci_dev *dev,
 	     (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_EC)))
 		return -ENODEV;
 
+	if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_EC)
+		pcie_walk_rcec(dev, pcie_hook_rcec, dev);
+
 	status = pcie_port_device_register(dev);
 	if (status)
 		return status;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 34c1c4f45288..e920f29df40b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -326,6 +326,9 @@ struct pci_dev {
 #ifdef CONFIG_PCIEAER
 	u16		aer_cap;	/* AER capability offset */
 	struct aer_stats *aer_stats;	/* AER stats for this device */
+#endif
+#ifdef CONFIG_PCIEPORTBUS
+	struct pci_dev	*rcec;		/* Associated RCEC device */
 #endif
 	u8		pcie_cap;	/* PCIe capability offset */
 	u8		msi_cap;	/* MSI capability offset */
-- 
2.27.0