[PATCH AUTOSEL for 4.9 001/100] cxl: Route eeh events to all slices for pci_channel_io_perm_failure state

[alexander . levin]

From: Vaibhav Jain <vaibhav@xxxxxxxxxxxxxxxxxx>

[ Upstream commit 07f5ab6002a4f0b633f3495157166f9f6180871b ]

Fix a boundary condition where in some cases an eeh event with state ==
pci_channel_io_perm_failure wont be passed on to a driver attached to
the virtual PCI device associated with a slice. This will happen in case
the slice just before (n-1) doesn't have any vPHB bus associated with
it, that results in an early return from cxl_pci_error_detected()
callback.

With state == pci_channel_io_perm_failure, the adapter will be removed
irrespective of the return value of cxl_vphb_error_detected(). So we now
always return PCI_ERS_RESULT_DISCONNECTED for this case i.e even if
the AFU isn't using a vPHB (currently returns PCI_ERS_RESULT_NONE).

Fixes: e4f5fc001a6("cxl: Do not create vPHB if there are no AFU configuration records")
Signed-off-by: Vaibhav Jain <vaibhav@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Andrew Donnellan <andrew.donnellan@xxxxxxxxxxx>
Acked-by: Frederic Barrat <fbarrat@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
 drivers/misc/cxl/pci.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index eef202d4399b..9b8628273b1b 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1793,15 +1793,14 @@ static pci_ers_result_t cxl_pci_error_detected(struct pci_dev *pdev,
 
 	/* If we're permanently dead, give up. */
 	if (state == pci_channel_io_perm_failure) {
-		/* Tell the AFU drivers; but we don't care what they
-		 * say, we're going away.
-		 */
 		for (i = 0; i < adapter->slices; i++) {
 			afu = adapter->afu[i];
-			/* Only participate in EEH if we are on a virtual PHB */
-			if (afu->phb == NULL)
-				return PCI_ERS_RESULT_NONE;
-			cxl_vphb_error_detected(afu, state);
+			/*
+			 * Tell the AFU drivers; but we don't care what they
+			 * say, we're going away.
+			 */
+			if (afu->phb != NULL)
+				cxl_vphb_error_detected(afu, state);
 		}
 		return PCI_ERS_RESULT_DISCONNECT;
 	}
-- 
2.11.0