powerpc/eeh: Rework eeh_ops->probe()

With the EEH early probe now being pseries specific there's no need for
eeh_ops->probe() to take a pci_dn. Instead, we can make it take a pci_dev
and use the probe function to map a pci_dev to an eeh_dev. This allows
the platform to implement it's own method for finding (or creating) an
eeh_dev for a given pci_dev which also removes a use of pci_dn in
generic EEH code.

This patch also renames eeh_device_add_late() to eeh_device_probe(). This
better reflects what it does does and removes the last vestiges of the
early/late EEH probe split.

Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-6-oohall@gmail.com

2 files changed, 36 insertions, 17 deletions

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index eaa8dfefa124..79409e005fcd 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -41,7 +41,7 @@ static int eeh_event_irq = -EINVAL;
 void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
 {
 	dev_dbg(&pdev->dev, "EEH: Setting up device\n");
-	eeh_add_device_late(pdev);
+	eeh_probe_device(pdev);
 }
 
 static int pnv_eeh_init(void)
@@ -340,23 +340,13 @@ static int pnv_eeh_find_ecap(struct pci_dn *pdn, int cap)
 
 /**
  * pnv_eeh_probe - Do probe on PCI device
- * @pdn: PCI device node
- * @data: unused
+ * @pdev: pci_dev to probe
  *
- * When EEH module is installed during system boot, all PCI devices
- * are checked one by one to see if it supports EEH. The function
- * is introduced for the purpose. By default, EEH has been enabled
- * on all PCI devices. That's to say, we only need do necessary
- * initialization on the corresponding eeh device and create PE
- * accordingly.
- *
- * It's notable that's unsafe to retrieve the EEH device through
- * the corresponding PCI device. During the PCI device hotplug, which
- * was possiblly triggered by EEH core, the binding between EEH device
- * and the PCI device isn't built yet.
+ * Create, or find the existing, eeh_dev for this pci_dev.
  */
-static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
+static struct eeh_dev *pnv_eeh_probe(struct pci_dev *pdev)
 {
+	struct pci_dn *pdn = pci_get_pdn(pdev);
 	struct pci_controller *hose = pdn->phb;
 	struct pnv_phb *phb = hose->private_data;
 	struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
@@ -373,6 +363,14 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 	if (!edev || edev->pe)
 		return NULL;
 
+	/* already configured? */
+	if (edev->pdev) {
+		pr_debug("%s: found existing edev for %04x:%02x:%02x.%01x\n",
+			__func__, hose->global_number, config_addr >> 8,
+			PCI_SLOT(config_addr), PCI_FUNC(config_addr));
+		return edev;
+	}
+
 	/* Skip for PCI-ISA bridge */
 	if ((pdn->class_code >> 8) == PCI_CLASS_BRIDGE_ISA)
 		return NULL;
@@ -464,7 +462,7 @@ static void *pnv_eeh_probe(struct pci_dn *pdn, void *data)
 
 	eeh_edev_dbg(edev, "EEH enabled on device\n");
 
-	return NULL;
+	return edev;
 }
 
 /**
diff --git a/arch/powerpc/platforms/pseries/eeh_pseries.c b/arch/powerpc/platforms/pseries/eeh_pseries.c
index 1ca7cf0fc0d8..845342814edc 100644
--- a/arch/powerpc/platforms/pseries/eeh_pseries.c
+++ b/arch/powerpc/platforms/pseries/eeh_pseries.c
@@ -77,7 +77,7 @@ void pseries_pcibios_bus_add_device(struct pci_dev *pdev)
 		eeh_add_to_parent_pe(edev);   /* Add as VF PE type */
 	}
 #endif
-	eeh_add_device_late(pdev);
+	eeh_probe_device(pdev);
 }
 
 /*
@@ -335,6 +335,26 @@ void pseries_eeh_init_edev(struct pci_dn *pdn)
 	eeh_save_bars(edev);
 }
 
+static struct eeh_dev *pseries_eeh_probe(struct pci_dev *pdev)
+{
+	struct eeh_dev *edev;
+	struct pci_dn *pdn;
+
+	pdn = pci_get_pdn_by_devfn(pdev->bus, pdev->devfn);
+	if (!pdn)
+		return NULL;
+
+	/*
+	 * If the system supports EEH on this device then the eeh_dev was
+	 * configured and inserted into a PE in pseries_eeh_init_edev()
+	 */
+	edev = pdn_to_eeh_dev(pdn);
+	if (!edev || !edev->pe)
+		return NULL;
+
+	return edev;
+}
+
 /**
  * pseries_eeh_init_edev_recursive - Enable EEH for the indicated device
  * @pdn: PCI device node
@@ -813,6 +833,7 @@ static int pseries_notify_resume(struct pci_dn *pdn)
 static struct eeh_ops pseries_eeh_ops = {
 	.name			= "pseries",
 	.init			= pseries_eeh_init,
+	.probe			= pseries_eeh_probe,
 	.set_option		= pseries_eeh_set_option,
 	.get_pe_addr		= pseries_eeh_get_pe_addr,
 	.get_state		= pseries_eeh_get_state,