[PATCH v1] powerpc/powernv/pci: fix PE in re-used pci_dn for pnv_pci_enable_device_hook

[Luming Yu]

after hot remove a pcie deivce with pci_dn having pnp_php driver attached,
pci rescan with echo 1 > /sys/bus/pci/rescan could fail with error
message like:
pci 0020:0e:00.0: BAR 0: assigned [mem 0x3fe801820000-0x3fe80182ffff
64bit]
nvme nvme1: pci function 0020:0e:00.0
nvme 0020:0e:00.0 pci_enable_device() blocked, no PE assigned.

It appears that the pci_dn object is reused with only pe_number
clobbered in the case. And a simple call to pnv_ioda_setup_dev_PE should
get PE number back and solve the problem.

Signed-off-by: Luming Yu <luming...@shingroup.cn>
---
v0 -> v1:
-clean up garbage leaked in git format patch that stems from git clone and 
checkout 
-conflicts of files in local windows filesystem with weird cases and names 
quriks.
---
 arch/powerpc/platforms/powernv/pci-ioda.c     |  11 +-
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c 
b/arch/powerpc/platforms/powernv/pci-ioda.c
index 28fac4770073..9d7add79ee3d 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2325,11 +2325,18 @@ static resource_size_t pnv_pci_default_alignment(void)
 static bool pnv_pci_enable_device_hook(struct pci_dev *dev)
 {
        struct pci_dn *pdn;
+       struct pnv_ioda_pe *pe;
 
        pdn = pci_get_pdn(dev);
-       if (!pdn || pdn->pe_number == IODA_INVALID_PE) {
-               pci_err(dev, "pci_enable_device() blocked, no PE assigned.\n");
+       if (!pdn)
                return false;
+
+       if (pdn->pe_number == IODA_INVALID_PE) {
+               pe = pnv_ioda_setup_dev_PE(dev);
+               if (!pe) {
+                       pci_err(dev, "pci_enable_device() blocked, no PE 
assigned.\n");
+                       return false;
+               }
        }
 
        return true;