[Very RFC 21/46] powernv/eeh: Rework finding an existing edev in probe_pdev()

[Oliver O'Halloran]

Use the pnv_eeh_find_edev() helper to look up the eeh_dev for a device
rather than doing it via the pci_dn.

Signed-off-by: Oliver O'Halloran <oohall at gmail.com>
---
 arch/powerpc/platforms/powernv/eeh-powernv.c | 44 ++++++++++++++------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/eeh-powernv.c b/arch/powerpc/platforms/powernv/eeh-powernv.c
index 6ba74836a9f8..1cd80b399995 100644
--- a/arch/powerpc/platforms/powernv/eeh-powernv.c
+++ b/arch/powerpc/platforms/powernv/eeh-powernv.c
@@ -374,20 +374,40 @@ static struct eeh_dev *pnv_eeh_probe_pdev(struct pci_dev *pdev)
 	int ret;
 	int config_addr = (pdev->bus->number << 8) | (pdev->devfn);
 
+	pci_dbg(pdev, "%s: probing\n", __func__);
+
 	/*
-	 * When probing the root bridge, which doesn't have any
-	 * subordinate PCI devices. We don't have OF node for
-	 * the root bridge. So it's not reasonable to continue
-	 * the probing.
+	 * EEH keeps the eeh_dev alive over a recovery pass even when the
+	 * corresponding pci_dev has been torn down. In that case we need
+	 * to find the existing eeh_dev and re-bind the two.
 	 */
-	if (!edev || edev->pe)
-		return NULL;
+	edev = pnv_eeh_find_edev(phb, config_addr);
+	if (edev) {
+		eeh_edev_dbg(edev, "Found existing edev!\n");
+
+		/*
+		 * XXX: eeh_remove_device() clears pdev so we shouldn't hit this
+		 * normally. I've found that screwing around with the pci probe
+		 * path can result in eeh_probe_pdev() being called twice. This
+		 * is harmless at the moment, but it's pretty strange so emit a
+		 * warning to be on the safe side.
+		 */
+		if (WARN_ON(edev->pdev))
+			eeh_edev_dbg(edev, "%s: already bound to a pdev!\n", __func__);
+
+		edev->pdev = pdev;
+
+		/* should we be doing something with REMOVED too? */
+		edev->mode &= EEH_DEV_DISCONNECTED;
+
+		/* update the primary bus if we need to */
+		// XXX: why do we need to do this? is the pci_bus going away? what cleared the flag?
+		if (!(edev->pe->state & EEH_PE_PRI_BUS)) {
+			edev->pe->bus = pdev->bus;
+			if (edev->pe->bus)
+				edev->pe->state |= EEH_PE_PRI_BUS;
+		}
 
-	/* 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;
 	}
 
@@ -395,8 +415,6 @@ static struct eeh_dev *pnv_eeh_probe_pdev(struct pci_dev *pdev)
 	if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
 		return NULL;
 
-	eeh_edev_dbg(edev, "Probing device\n");
-
 	/* Initialize eeh device */
 	edev->class_code = pdev->class;
 	edev->pcix_cap = pci_find_capability(pdev, PCI_CAP_ID_PCIX);
-- 
2.21.0