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Commit 95375f2a authored by Thomas Petazzoni's avatar Thomas Petazzoni Committed by Bjorn Helgaas
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PCI: mvebu: Fix PCI I/O mapping creation sequence 



Commit ee160438 ("PCI: mvebu: Only remap I/O space if configured") had
the side effect that the PCI I/O mapping was created much earlier than
before, at a point where the probe() of the driver could still fail. This
is for example a problem if one gets an -EPROBE_DEFER at some point during
probe(), after pci_ioremap_io() has been called.

Indeed, there is currently no function to undo what pci_ioremap_io() did,
and switching to pci_remap_iospace() is not an option in pci-mvebu due to
the need for special memory attributes on Armada 38x.

Reverting ee160438 ("PCI: mvebu: Only remap I/O space if configured")
would be a possibility, but it would require also reverting 42342073
("PCI: mvebu: Convert to use pci_host_bridge directly"). So instead, we use
an open-coded version of pci_host_probe() that creates the PCI I/O mapping
at a point where we are guaranteed not to fail anymore.

Fixes: ee160438 ("PCI: mvebu: Only remap I/O space if configured")
Reported-by: default avatarJan Kundrát <jan.kundrat@cesnet.cz>
Tested-by: default avatarJan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: default avatarThomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Acked-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
parent 573bcd38

drivers/pci/controller/pci-mvebu.c

+48 −4
Original line number Original line Diff line number Diff line
@@ -1145,7 +1145,6 @@ static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie) 
{

{

	struct device *dev = &pcie->pdev->dev;

	struct device *dev = &pcie->pdev->dev;

	struct device_node *np = dev->of_node;

	struct device_node *np = dev->of_node;

	unsigned int i;

	int ret;

	int ret;





	INIT_LIST_HEAD(&pcie->resources);

	INIT_LIST_HEAD(&pcie->resources);
@@ -1179,13 +1178,58 @@ static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie) 
					 resource_size(&pcie->io) - 1);

					 resource_size(&pcie->io) - 1);

		pcie->realio.name = "PCI I/O";

		pcie->realio.name = "PCI I/O";





		pci_add_resource(&pcie->resources, &pcie->realio);

	}



	return devm_request_pci_bus_resources(dev, &pcie->resources);

}



/*

 * This is a copy of pci_host_probe(), except that it does the I/O

 * remap as the last step, once we are sure we won't fail.

 *

 * It should be removed once the I/O remap error handling issue has

 * been sorted out.

 */

static int mvebu_pci_host_probe(struct pci_host_bridge *bridge)

{

	struct mvebu_pcie *pcie;

	struct pci_bus *bus, *child;

	int ret;



	ret = pci_scan_root_bus_bridge(bridge);

	if (ret < 0) {

		dev_err(bridge->dev.parent, "Scanning root bridge failed");

		return ret;

	}



	pcie = pci_host_bridge_priv(bridge);

	if (resource_size(&pcie->io) != 0) {

		unsigned int i;



		for (i = 0; i < resource_size(&pcie->realio); i += SZ_64K)

		for (i = 0; i < resource_size(&pcie->realio); i += SZ_64K)

			pci_ioremap_io(i, pcie->io.start + i);

			pci_ioremap_io(i, pcie->io.start + i);

	}





		pci_add_resource(&pcie->resources, &pcie->realio);

	bus = bridge->bus;



	/*

	 * We insert PCI resources into the iomem_resource and

	 * ioport_resource trees in either pci_bus_claim_resources()

	 * or pci_bus_assign_resources().

	 */

	if (pci_has_flag(PCI_PROBE_ONLY)) {

		pci_bus_claim_resources(bus);

	} else {

		pci_bus_size_bridges(bus);

		pci_bus_assign_resources(bus);



		list_for_each_entry(child, &bus->children, node)

			pcie_bus_configure_settings(child);

	}

	}





	return devm_request_pci_bus_resources(dev, &pcie->resources);

	pci_bus_add_devices(bus);

	return 0;

}

}





static int mvebu_pcie_probe(struct platform_device *pdev)

static int mvebu_pcie_probe(struct platform_device *pdev)
@@ -1268,7 +1312,7 @@ static int mvebu_pcie_probe(struct platform_device *pdev) 
	bridge->align_resource = mvebu_pcie_align_resource;

	bridge->align_resource = mvebu_pcie_align_resource;

	bridge->msi = pcie->msi;

	bridge->msi = pcie->msi;





	return pci_host_probe(bridge);

	return mvebu_pci_host_probe(bridge);

}

}





static const struct of_device_id mvebu_pcie_of_match_table[] = {

static const struct of_device_id mvebu_pcie_of_match_table[] = {