diff options
| author | Stefan Agner <stefan@agner.ch> | 2019-02-06 10:57:32 +0100 |
|---|---|---|
| committer | Stefan Agner <stefan.agner@toradex.com> | 2019-04-25 18:06:51 +0200 |
| commit | 0197a9cf06d5c0a45eeb97c7bff48a1dcb79b404 (patch) | |
| tree | 7b517c3d685613956b2ab785b0760efd534c1328 | |
| parent | d9f5deef4e642a2cb2b09d0e695422980574c56f (diff) | |
PCI: imx6: limit DBI register length
Define the length of the DBI registers and limit config space to its
length. This makes sure that the kernel does not access registers
beyond that point, avoiding the following abort on a i.MX 6Quad:
# cat /sys/devices/soc0/soc/1ffc000.pcie/pci0000\:00/0000\:00\:00.0/config
[ 100.021433] Unhandled fault: imprecise external abort (0x1406) at 0xb6ea7000
...
[ 100.056423] PC is at dw_pcie_read+0x50/0x84
[ 100.060790] LR is at dw_pcie_rd_own_conf+0x44/0x48
...
Signed-off-by: Stefan Agner <stefan@agner.ch>
| -rw-r--r-- | drivers/pci/controller/dwc/pci-imx6.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c index d411c7f0c6dc..070c5ea3abeb 100644 --- a/drivers/pci/controller/dwc/pci-imx6.c +++ b/drivers/pci/controller/dwc/pci-imx6.c @@ -43,6 +43,7 @@ enum imx6_pcie_variants { struct imx6_pcie_drvdata { enum imx6_pcie_variants variant; + int dbi_length; }; struct imx6_pcie { @@ -1093,6 +1094,7 @@ static void imx6_pcie_shutdown(struct platform_device *pdev) static const struct imx6_pcie_drvdata drvdata[] = { [IMX6Q] = { .variant = IMX6Q, + .dbi_length = 0x200, }, [IMX6SX] = { .variant = IMX6SX, @@ -1124,6 +1126,37 @@ static struct platform_driver imx6_pcie_driver = { .shutdown = imx6_pcie_shutdown, }; +static void imx6_pcie_quirk(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->bus; + struct pcie_port *pp = bus->sysdata; + + /* Bus parent is the PCI bridge, its parent is this platform driver */ + if (!bus->dev.parent || !bus->dev.parent->parent) + return; + + /* Make sure we only quirk devices associated with this driver */ + if (bus->dev.parent->parent->driver != &imx6_pcie_driver.driver) + return; + + if (bus->number == pp->root_bus_nr) { + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + struct imx6_pcie *imx6_pcie = to_imx6_pcie(pci); + + /* + * Limit config length to avoid the kernel reading beyond + * the register set and causing an abort on i.MX 6Quad + */ + if (imx6_pcie->drvdata->dbi_length) { + dev->cfg_size = imx6_pcie->drvdata->dbi_length; + dev_info(&dev->dev, "Limiting cfg_size to %d\n", + dev->cfg_size); + } + } +} +DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_SYNOPSYS, 0xabcd, + PCI_CLASS_BRIDGE_PCI, 8, imx6_pcie_quirk); + static int __init imx6_pcie_init(void) { /* |