[PATCH 1/3] PCI: host-generic: Set driver_data before calling gen_pci_init()

From: Marc Zyngier <maz@kernel.org>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Alyssa Rosenzweig" <alyssa@rosenzweig.io>,
	"Rob Herring" <robh@kernel.org>,
	"Manivannan Sadhasivam" <mani@kernel.org>,
	"Lorenzo Pieralisi" <lpieralisi@kernel.org>,
	"Krzysztof Wilczyński" <kwilczynski@kernel.org>,
	"Janne Grunau" <j@jannau.net>,
	"Geert Uytterhoeven" <geert+renesas@glider.be>,
	linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] PCI: host-generic: Set driver_data before calling gen_pci_init()
Date: Wed, 25 Jun 2025 12:18:04 +0100	[thread overview]
Message-ID: <20250625111806.4153773-2-maz@kernel.org> (raw)
In-Reply-To: <20250625111806.4153773-1-maz@kernel.org>

From: Geert Uytterhoeven <geert+renesas@glider.be>

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: afc0a570bb613871 ("PCI: host-generic: Extract an ECAM bridge creation helper from pci_host_common_probe()")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/774290708a6f0f683711914fda110742c18a7fb2.1750787223.git.geert+renesas@glider.be
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 drivers/pci/controller/pci-host-common.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pci-host-common.c b/drivers/pci/controller/pci-host-common.c
index b0992325dd65f..b370528638471 100644
--- a/drivers/pci/controller/pci-host-common.c
+++ b/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;
-- 
2.39.2


