PCI: host-generic: Set driver_data before calling gen_pci_init()

JIRA: https://issues.redhat.com/browse/RHEL-107597
Upstream Status: bdb32a0

commit bdb32a0
Author: Geert Uytterhoeven <geert+renesas@glider.be>
Date:   Wed Jun 25 12:18:04 2025 +0100

    PCI: host-generic: Set driver_data before calling gen_pci_init()

    On MicroChip MPFS Icicle:

      microchip-pcie 2000000000.pcie: host bridge /soc/pcie@2000000000 ranges:
      microchip-pcie 2000000000.pcie: Parsing ranges property...
      microchip-pcie 2000000000.pcie:      MEM 0x2008000000..0x2087ffffff -> 0x0008000000
      Unable to handle kernel NULL pointer dereference at virtual address 0000000000000368
      Current swapper/0 pgtable: 4K pagesize, 39-bit VAs, pgdp=0x00000000814f1000
      [0000000000000368] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
      Oops [#1]
      Modules linked in:
      CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.15.0-rc1-icicle-00003-gafc0a570bb61 #232 NONE
      Hardware name: Microchip PolarFire-SoC Icicle Kit (DT)
      [...]
      [<ffffffff803fb8a4>] plda_pcie_setup_iomems+0xe/0x78
      [<ffffffff803fc246>] mc_platform_init+0x80/0x1d2
      [<ffffffff803f9c88>] pci_ecam_create+0x104/0x1e2
      [<ffffffff8000adbe>] pci_host_common_init+0x120/0x228
      [<ffffffff8000af42>] pci_host_common_probe+0x7c/0x8a

    The initialization of driver_data was moved after the call to
    gen_pci_init(), while the pci_ecam_ops.init() callback
    mc_platform_init() expects it has already been initialized.

    Fix this by moving the initialization of driver_data up.

    Fixes: afc0a57 ("PCI: host-generic: Extract an ECAM bridge creation helper from pci_host_common_probe()")
    Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
    Signed-off-by: Marc Zyngier <maz@kernel.org>
    Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
    Link: https://lore.kernel.org/r/774290708a6f0f683711914fda110742c18a7fb2.1750787223.git.geert+renesas@glider.be
    Link: https://patch.msgid.link/20250625111806.4153773-2-maz@kernel.org

Signed-off-by: Myron Stowe <mstowe@redhat.com>

Author: Myron Stowe

drivers/pci/controller/pci-host-common.c

@@ -64,13 +64,13 @@ int pci_host_common_init(struct platform_device *pdev,
 
 	of_pci_check_probe_only();
 
+	platform_set_drvdata(pdev, bridge);
+
 	/* Parse and map our Configuration Space windows */
 	cfg = gen_pci_init(dev, bridge, ops);
 	if (IS_ERR(cfg))
 		return PTR_ERR(cfg);
 
-	platform_set_drvdata(pdev, bridge);
-
 	bridge->sysdata = cfg;
 	bridge->ops = (struct pci_ops *)&ops->pci_ops;
 	bridge->enable_device = ops->enable_device;