releases/4.9.30/cxl-route-eeh-events-to-all-drivers-in-cxl_pci_error_detected.patch

   1 From 4f58f0bf155e87dda31a3088b1e107fa9dd79f0e Mon Sep 17 00:00:00 2001
   2 From: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
   3 Date: Thu, 27 Apr 2017 10:58:22 +0530
   4 Subject: cxl: Route eeh events to all drivers in cxl_pci_error_detected()
   5
   6 From: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
   7
   8 commit 4f58f0bf155e87dda31a3088b1e107fa9dd79f0e upstream.
   9
  10 Fix a boundary condition where in some cases an eeh event that results
  11 in card reset isn't passed on to a driver attached to the virtual PCI
  12 device associated with a slice. This will happen in case when a slice
  13 attached device driver returns a value other than
  14 PCI_ERS_RESULT_NEED_RESET from the eeh error_detected() callback. This
  15 would result in an early return from cxl_pci_error_detected() and
  16 other drivers attached to other AFUs on the card wont be notified.
  17
  18 The patch fixes this by making sure that all slice attached
  19 device-drivers are notified and the return values from
  20 error_detected() callback are aggregated in a scheme where request for
  21 'disconnect' trumps all and 'none' trumps 'need_reset'.
  22
  23 Fixes: 9e8df8a21963 ("cxl: EEH support")
  24 Signed-off-by: Vaibhav Jain <vaibhav@linux.vnet.ibm.com>
  25 Reviewed-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
  26 Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
  27 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
  28 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  29
  30 ---
  31  drivers/misc/cxl/pci.c |   15 +++++++++------
  32  1 file changed, 9 insertions(+), 6 deletions(-)
  33
  34 --- a/drivers/misc/cxl/pci.c
  35 +++ b/drivers/misc/cxl/pci.c
  36 @@ -1779,7 +1779,7 @@ static pci_ers_result_t cxl_pci_error_de
  37  {
  38         struct cxl *adapter = pci_get_drvdata(pdev);
  39         struct cxl_afu *afu;
  40 -       pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET;
  41 +       pci_ers_result_t result = PCI_ERS_RESULT_NEED_RESET, afu_result;
  42         int i;
  43
  44         /* At this point, we could still have an interrupt pending.
  45 @@ -1884,15 +1884,18 @@ static pci_ers_result_t cxl_pci_error_de
  46         for (i = 0; i < adapter->slices; i++) {
  47                 afu = adapter->afu[i];
  48
  49 -               result = cxl_vphb_error_detected(afu, state);
  50 -
  51 -               /* Only continue if everyone agrees on NEED_RESET */
  52 -               if (result != PCI_ERS_RESULT_NEED_RESET)
  53 -                       return result;
  54 +               afu_result = cxl_vphb_error_detected(afu, state);
  55
  56                 cxl_context_detach_all(afu);
  57                 cxl_ops->afu_deactivate_mode(afu, afu->current_mode);
  58                 pci_deconfigure_afu(afu);
  59 +
  60 +               /* Disconnect trumps all, NONE trumps NEED_RESET */
  61 +               if (afu_result == PCI_ERS_RESULT_DISCONNECT)
  62 +                       result = PCI_ERS_RESULT_DISCONNECT;
  63 +               else if ((afu_result == PCI_ERS_RESULT_NONE) &&
  64 +                        (result == PCI_ERS_RESULT_NEED_RESET))
  65 +                       result = PCI_ERS_RESULT_NONE;
  66         }
  67
  68         /* should take the context lock here */