PCI: Add generic pcie_wait_for_link() interface

Clients such as hotplug and Downstream Port Containment (DPC) both need to
wait until a link becomes active or inactive.

Add a generic pcie_wait_link_active() interface and use it instead of
duplicating the code.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 18a42f8..e0c2b8e 100644 (file)
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -231,25 +231,11 @@ bool pciehp_check_link_active(struct controller *ctrl)
        return ret;
 }
 
-static void __pcie_wait_link_active(struct controller *ctrl, bool active)
-{
-       int timeout = 1000;
-
-       if (pciehp_check_link_active(ctrl) == active)
-               return;
-       while (timeout > 0) {
-               msleep(10);
-               timeout -= 10;
-               if (pciehp_check_link_active(ctrl) == active)
-                       return;
-       }
-       ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n",
-                       active ? "set" : "cleared");
-}
-
 static void pcie_wait_link_active(struct controller *ctrl)
 {
-       __pcie_wait_link_active(ctrl, true);
+       struct pci_dev *pdev = ctrl_dev(ctrl);
+
+       pcie_wait_for_link(pdev, true);
 }
 
 static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e597655..764bf64 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4138,6 +4138,35 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
 
        return pci_dev_wait(dev, "PM D3->D0", PCIE_RESET_READY_POLL_MS);
 }
+/**
+ * pcie_wait_for_link - Wait until link is active or inactive
+ * @pdev: Bridge device
+ * @active: waiting for active or inactive?
+ *
+ * Use this to wait till link becomes active or inactive.
+ */
+bool pcie_wait_for_link(struct pci_dev *pdev, bool active)
+{
+       int timeout = 1000;
+       bool ret;
+       u16 lnk_status;
+
+       for (;;) {
+               pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
+               ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA);
+               if (ret == active)
+                       return true;
+               if (timeout <= 0)
+                       break;
+               msleep(10);
+               timeout -= 10;
+       }
+
+       pci_info(pdev, "Data Link Layer Link Active not %s in 1000 msec\n",
+                active ? "set" : "cleared");
+
+       return false;
+}
 
 void pci_reset_secondary_bus(struct pci_dev *dev)
 {

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 023f7cf..cec9d8c 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -353,6 +353,7 @@ static inline resource_size_t pci_resource_alignment(struct pci_dev *dev,
 
 void pci_enable_acs(struct pci_dev *dev);
 
+bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
 #ifdef CONFIG_PCIEASPM
 void pcie_aspm_init_link_state(struct pci_dev *pdev);
 void pcie_aspm_exit_link_state(struct pci_dev *pdev);

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 8c57d60..80ec384 100644 (file)
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -68,19 +68,9 @@ static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
 
 static void dpc_wait_link_inactive(struct dpc_dev *dpc)
 {
-       unsigned long timeout = jiffies + HZ;
        struct pci_dev *pdev = dpc->dev->port;
-       struct device *dev = &dpc->dev->device;
-       u16 lnk_status;
 
-       pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
-       while (lnk_status & PCI_EXP_LNKSTA_DLLLA &&
-                                       !time_after(jiffies, timeout)) {
-               msleep(10);
-               pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status);
-       }
-       if (lnk_status & PCI_EXP_LNKSTA_DLLLA)
-               dev_warn(dev, "Link state not disabled for DPC event\n");
+       pcie_wait_for_link(pdev, false);
 }
 
 static void dpc_work(struct work_struct *work)