Commit c12ff1df authored by Yu Zhao's avatar Yu Zhao Committed by Jesse Barnes

PCI: support Secondary Bus Reset

PCI-to-PCI Bridge 1.2 specifies that the Secondary Bus Reset bit can
force the assertion of RST# on the secondary interface, which can be
used to reset all devices including subordinates under this bus. This
can be used to reset a function if this function is the only device
under this bus.
Reviewed-by: default avatarKenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: default avatarYu Zhao <yu.zhao@intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent f85876ba
......@@ -2162,6 +2162,33 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
return 0;
}
static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
{
u16 ctrl;
struct pci_dev *pdev;
if (dev->subordinate)
return -ENOTTY;
list_for_each_entry(pdev, &dev->bus->devices, bus_list)
if (pdev != dev)
return -ENOTTY;
if (probe)
return 0;
pci_read_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, &ctrl);
ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
msleep(100);
ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
pci_write_config_word(dev->bus->self, PCI_BRIDGE_CONTROL, ctrl);
msleep(100);
return 0;
}
static int pci_dev_reset(struct pci_dev *dev, int probe)
{
int rc;
......@@ -2183,6 +2210,10 @@ static int pci_dev_reset(struct pci_dev *dev, int probe)
goto done;
rc = pci_pm_reset(dev, probe);
if (rc != -ENOTTY)
goto done;
rc = pci_parent_bus_reset(dev, probe);
done:
if (!probe) {
up(&dev->dev.sem);
......
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