Merge branches 'iommu/fixes', 'x86/amd', 'groups', 'arm/tegra' and 'api/domain-attr...

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / pci / pci.c

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 77cb54a65cde10885d7b0b4406ae103faca9e8a2..1ccf7d49f5227c91542fdfd2676a448fda95acde 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1744,11 +1744,6 @@ int pci_prepare_to_sleep(struct pci_dev *dev)
        if (target_state == PCI_POWER_ERROR)
                return -EIO;
 
-       /* Some devices mustn't be in D3 during system sleep */
-       if (target_state == PCI_D3hot &&
-                       (dev->dev_flags & PCI_DEV_FLAGS_NO_D3_DURING_SLEEP))
-               return 0;
-
        pci_enable_wake(dev, target_state, device_may_wakeup(&dev->dev));
 
        error = pci_set_power_state(dev, target_state);
@@ -2364,6 +2359,75 @@ void pci_enable_acs(struct pci_dev *dev)
        pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
 }
 
+/**
+ * pci_acs_enabled - test ACS against required flags for a given device
+ * @pdev: device to test
+ * @acs_flags: required PCI ACS flags
+ *
+ * Return true if the device supports the provided flags.  Automatically
+ * filters out flags that are not implemented on multifunction devices.
+ */
+bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags)
+{
+       int pos, ret;
+       u16 ctrl;
+
+       ret = pci_dev_specific_acs_enabled(pdev, acs_flags);
+       if (ret >= 0)
+               return ret > 0;
+
+       if (!pci_is_pcie(pdev))
+               return false;
+
+       /* Filter out flags not applicable to multifunction */
+       if (pdev->multifunction)
+               acs_flags &= (PCI_ACS_RR | PCI_ACS_CR |
+                             PCI_ACS_EC | PCI_ACS_DT);
+
+       if (pdev->pcie_type == PCI_EXP_TYPE_DOWNSTREAM ||
+           pdev->pcie_type == PCI_EXP_TYPE_ROOT_PORT ||
+           pdev->multifunction) {
+               pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ACS);
+               if (!pos)
+                       return false;
+
+               pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl);
+               if ((ctrl & acs_flags) != acs_flags)
+                       return false;
+       }
+
+       return true;
+}
+
+/**
+ * pci_acs_path_enable - test ACS flags from start to end in a hierarchy
+ * @start: starting downstream device
+ * @end: ending upstream device or NULL to search to the root bus
+ * @acs_flags: required flags
+ *
+ * Walk up a device tree from start to end testing PCI ACS support.  If
+ * any step along the way does not support the required flags, return false.
+ */
+bool pci_acs_path_enabled(struct pci_dev *start,
+                         struct pci_dev *end, u16 acs_flags)
+{
+       struct pci_dev *pdev, *parent = start;
+
+       do {
+               pdev = parent;
+
+               if (!pci_acs_enabled(pdev, acs_flags))
+                       return false;
+
+               if (pci_is_root_bus(pdev->bus))
+                       return (end == NULL);
+
+               parent = pdev->bus->self;
+       } while (pdev != end);
+
+       return true;
+}
+
 /**
  * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge
  * @dev: the PCI device