[PATCH] powerpc/powernv: Fix the state of root PE

[Gavin Shan]

The PE for root bus (root PE) can be removed because of PCI hot
remove in EEH recovery path for fenced PHB error. We need update
@phb->root_pe_populated accordingly so that the root PE can be
populated again in forthcoming PCI hot add path. Also, the PE
shouldn't be destroyed as it's global and reserved resource.

Fixes: c5f7700bbd2e ("powerpc/powernv: Dynamically release PE")
Reported-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>
Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index e98f4a8..c38a6a1 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -3426,7 +3426,16 @@ static void pnv_ioda_release_pe(struct pnv_ioda_pe *pe)
 		}
 	}
 
-	pnv_ioda_free_pe(pe);
+	/* The PE for root bus can be removed because of hotplug in EEH
+	 * recovery for fenced PHB error. We need mark the PE dead so
+	 * that it can be populated again in PCI hot add path. The PE
+	 * shouldn't be destroyed as it's the global reserved resource.
+	 */
+	if (phb->ioda.root_pe_populated &&
+	    phb->ioda.root_pe_idx == pe->pe_number)
+		phb->ioda.root_pe_populated = false;
+	else
+		pnv_ioda_free_pe(pe);
 }
 
 static void pnv_pci_release_device(struct pci_dev *pdev)
-- 
2.1.0