diff options
| -rw-r--r-- | drivers/pci/pci-sysfs.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index fdefa7dcd15..010e01c4bd4 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -131,6 +131,46 @@ is_enabled_store(struct device *dev, struct device_attribute *attr, return count; } +static ssize_t +msi_bus_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + + if (!pdev->subordinate) + return 0; + + return sprintf (buf, "%u\n", + !(pdev->subordinate->bus_flags & PCI_BUS_FLAGS_NO_MSI)); +} + +static ssize_t +msi_bus_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pci_dev *pdev = to_pci_dev(dev); + + /* bad things may happen if the no_msi flag is changed + * while some drivers are loaded */ + if (!capable(CAP_SYS_ADMIN)) + return count; + + if (!pdev->subordinate) + return count; + + if (*buf == '0') { + pdev->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI; + dev_warn(&pdev->dev, "forced subordinate bus to not support MSI," + " bad things could happen.\n"); + } + + if (*buf == '1') { + pdev->subordinate->bus_flags &= ~PCI_BUS_FLAGS_NO_MSI; + dev_warn(&pdev->dev, "forced subordinate bus to support MSI," + " bad things could happen.\n"); + } + + return count; +} struct device_attribute pci_dev_attrs[] = { __ATTR_RO(resource), @@ -145,6 +185,7 @@ struct device_attribute pci_dev_attrs[] = { __ATTR(enable, 0600, is_enabled_show, is_enabled_store), __ATTR(broken_parity_status,(S_IRUGO|S_IWUSR), broken_parity_status_show,broken_parity_status_store), + __ATTR(msi_bus, 0644, msi_bus_show, msi_bus_store), __ATTR_NULL, }; |