powerpc/eeh: Fix PE#0 check in eeh_add_to_parent_pe()

The function eeh_add_parent_pe() is used to create a PE or add one
edev to its parent PE. Current code checks if PE#0 is valid for the
later case. Actually, we should validate PE#0 for both cases when
EEH core regards PE#0 as invalid one (without flag EEH_VALID_PE_ZERO).
Otherwise, not all EEH devices can be added to its parent PE#0 for
EEH on P7IOC.

The patch fixes the issue by validating PE#0 for the two cases. So far,
we don't have PE#0 for EEH on P7IOC, but it will show up when we enable
M64 for P7IOC. The patch also makes the error message more meaningful.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 7 insertions, 6 deletions

diff --git a/arch/powerpc/kernel/eeh_pe.c b/arch/powerpc/kernel/eeh_pe.c
index f33ceccf6876..35f0b62259bb 100644
--- a/arch/powerpc/kernel/eeh_pe.c
+++ b/arch/powerpc/kernel/eeh_pe.c
@@ -328,6 +328,13 @@ int eeh_add_to_parent_pe(struct eeh_dev *edev)
 {
         struct eeh_pe *pe, *parent;
 
+        /* Check if the PE number is valid */
+        if (!eeh_has_flag(EEH_VALID_PE_ZERO) && !edev->pe_config_addr) {
+                pr_err("%s: Invalid PE#0 for edev 0x%x on PHB#%d\n",
+                       __func__, edev->config_addr, edev->phb->global_number);
+                return -EINVAL;
+        }
+
         /*
          * Search the PE has been existing or not according
          * to the PE address. If that has been existing, the
@@ -336,12 +343,6 @@ int eeh_add_to_parent_pe(struct eeh_dev *edev)
          */
         pe = eeh_pe_get(edev);
         if (pe && !(pe->type & EEH_PE_INVALID)) {
-                if (!edev->pe_config_addr) {
-                        pr_err("%s: PE with addr 0x%x already exists\n",
-                                __func__, edev->config_addr);
-                        return -EEXIST;
-                }
-
                 /* Mark the PE as type of PCI bus */
                 pe->type = EEH_PE_BUS;
                 edev->pe = pe;