PCI: Use PCI_EXP_SLTCAP_PSN mask when extracting slot number

Use PCI_EXP_SLTCAP_PSN mask to make it easier to find where the
Physical Slot Number is used.

The Physical Slot Number is bits 31:19 of the Slot Capabilities Register,
and slot_cap is a u32, so the mask is technically unnecessary, but it's
helpful for human readers.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/hotplug/pciehp_acpi.c b/drivers/pci/hotplug/pciehp_acpi.c
index 24d709b..ead7c53 100644 (file)
--- a/drivers/pci/hotplug/pciehp_acpi.c
+++ b/drivers/pci/hotplug/pciehp_acpi.c
@@ -90,7 +90,7 @@ static int __init dummy_probe(struct pcie_device *dev)
        slot = kzalloc(sizeof(*slot), GFP_KERNEL);
        if (!slot)
                return -ENOMEM;
-       slot->number = slot_cap >> 19;
+       slot->number = (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19;
        list_for_each_entry(tmp, &dummy_slots, list) {
                if (tmp->number == slot->number)
                        dup_slot_id++;