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PCI: mvebu: Fix PCI I/O mapping creation sequence

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Commit ee1604381a ("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 ee1604381a ("PCI: mvebu: Only remap I/O space if configured")
would be a possibility, but it would require also reverting 42342073e3
("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: ee1604381a ("PCI: mvebu: Only remap I/O space if configured")
Reported-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Tested-by: Jan Kundrát <jan.kundrat@cesnet.cz>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
This commit is contained in:
Thomas Petazzoni 2018-10-01 14:49:34 +02:00 committed by Bjorn Helgaas
parent 573bcd3809
commit 95375f2ab2
1 changed files with 49 additions and 5 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

54
drivers/pci/controller/pci-mvebu.c
View file

@ -1145,7 +1145,6 @@ static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
{
struct device *dev = &pcie->pdev->dev;
struct device_node *np = dev->of_node;
unsigned int i;
int ret;
INIT_LIST_HEAD(&pcie->resources);
@ -1179,15 +1178,60 @@ static int mvebu_pcie_parse_request_resources(struct mvebu_pcie *pcie)
resource_size(&pcie->io) - 1);
pcie->realio.name = "PCI I/O";
for (i = 0; i < resource_size(&pcie->realio); i += SZ_64K)
pci_ioremap_io(i, pcie->io.start + i);
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)
pci_ioremap_io(i, pcie->io.start + i);
}
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);
}
pci_bus_add_devices(bus);
return 0;
}
static int mvebu_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@ -1268,7 +1312,7 @@ static int mvebu_pcie_probe(struct platform_device *pdev)
bridge->align_resource = mvebu_pcie_align_resource;
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[] = {