From db047f8a931275e50563dd79c3d62d977074959a Mon Sep 17 00:00:00 2001 From: Lorenzo Pieralisi Date: Mon, 15 Aug 2016 17:50:41 +0100 Subject: [PATCH] PCI: aardvark: Fix pci_remap_iospace() failure path On ARM/ARM64 architectures, PCI IO ports are emulated through memory mapped IO, by reserving a chunk of virtual address space starting at PCI_IOBASE and by mapping the PCI host bridge's memory address space driving PCI IO cycles to it. PCI host bridge drivers that enable downstream PCI IO cycles map the host bridge memory address responding to PCI IO cycles to the fixed virtual address space through the pci_remap_iospace() API. This means that if the pci_remap_iospace() function fails, the corresponding host bridge PCI IO resource must be considered invalid, in that there is no way for the kernel to actually drive PCI IO transactions if the memory addresses responding to PCI IO cycles cannot be mapped into the CPU virtual address space. The PCI aardvark host bridge driver does not remove the PCI IO resource from the host bridge resource windows if the pci_remap_iospace() call fails; this is an actual bug in that the PCI host bridge would consider the PCI IO resource valid (and possibly assign it to downstream devices) even if the kernel was not able to map the PCI host bridge memory address driving IO cycle to the CPU virtual address space (ie pci_remap_iospace() failures). Fix the PCI host bridge driver pci_remap_iospace() failure path, by destroying the PCI host bridge PCI IO resources retrieved through firmware when the pci_remap_iospace() function call fails, therefore preventing the kernel from adding the respective PCI IO resource to the list of PCI host bridge valid resources, fixing the issue. Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas CC: Thomas Petazzoni --- drivers/pci/host/pci-aardvark.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/pci/host/pci-aardvark.c b/drivers/pci/host/pci-aardvark.c index ef9893fa3176..4f5e567fd7e0 100644 --- a/drivers/pci/host/pci-aardvark.c +++ b/drivers/pci/host/pci-aardvark.c @@ -848,7 +848,7 @@ static int advk_pcie_parse_request_of_pci_ranges(struct advk_pcie *pcie) int err, res_valid = 0; struct device *dev = &pcie->pdev->dev; struct device_node *np = dev->of_node; - struct resource_entry *win; + struct resource_entry *win, *tmp; resource_size_t iobase; INIT_LIST_HEAD(&pcie->resources); @@ -862,7 +862,7 @@ static int advk_pcie_parse_request_of_pci_ranges(struct advk_pcie *pcie) if (err) goto out_release_res; - resource_list_for_each_entry(win, &pcie->resources) { + resource_list_for_each_entry_safe(win, tmp, &pcie->resources) { struct resource *res = win->res; switch (resource_type(res)) { @@ -874,9 +874,11 @@ static int advk_pcie_parse_request_of_pci_ranges(struct advk_pcie *pcie) lower_32_bits(res->start), OB_PCIE_IO); err = pci_remap_iospace(res, iobase); - if (err) + if (err) { dev_warn(dev, "error %d: failed to map resource %pR\n", err, res); + resource_list_destroy_entry(win); + } break; case IORESOURCE_MEM: advk_pcie_set_ob_win(pcie, 0,