diff options
authorLorenzo Pieralisi <lorenzo.pieralisi@arm.com>2016-08-15 17:50:44 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-10-31 05:02:15 -0600
commitc76bf06c9cd4ad8d09bb072ffe53e5643cf3ef48 (patch)
parent847fd175244d1a8862a66cd54dd6bc7277607848 (diff)
PCI: rcar: Fix pci_remap_iospace() failure path
commit 5e8c873270cc618e3326eb6a47437b517ef85c52 upstream. 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 bridges 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 rcar 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: 5d2917d469fa ("PCI: rcar: Convert to DT resource parsing API") Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> CC: Phil Edworthy <phil.edworthy@renesas.com> CC: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 65db7a221509..5f7fcc971cae 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -945,7 +945,7 @@ static int rcar_pcie_parse_request_of_pci_ranges(struct rcar_pcie *pci)
struct device *dev = pci->dev;
struct device_node *np = dev->of_node;
resource_size_t iobase;
- struct resource_entry *win;
+ struct resource_entry *win, *tmp;
err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources, &iobase);
if (err)
@@ -955,14 +955,17 @@ static int rcar_pcie_parse_request_of_pci_ranges(struct rcar_pcie *pci)
if (err)
goto out_release_res;
- resource_list_for_each_entry(win, &pci->resources) {
+ resource_list_for_each_entry_safe(win, tmp, &pci->resources) {
struct resource *res = win->res;
if (resource_type(res) == IORESOURCE_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);
+ }