[PATCH v17 1/9] PCI: Add generic pcie_wait_for_link() interface

[Oza Pawandeep]

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 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 18a42f8..e0c2b8e 100644
--- 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
--- 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, _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
--- 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
--- 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 = >dev->device;
-   u16 lnk_status;
 
-   pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, _status);
-   while (lnk_status & PCI_EXP_LNKSTA_DLLLA &&
-   !time_after(jiffies, timeout)) {
-   msleep(10);
-   pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, _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)
-- 
2.7.4

[PATCH v17 1/9] PCI: Add generic pcie_wait_for_link() interface

[Oza Pawandeep]

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 
Signed-off-by: Bjorn Helgaas 
Reviewed-by: Keith Busch 

diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index 18a42f8..e0c2b8e 100644
--- 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
--- 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, _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
--- 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
--- 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 = >dev->device;
-   u16 lnk_status;
 
-   pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, _status);
-   while (lnk_status & PCI_EXP_LNKSTA_DLLLA &&
-   !time_after(jiffies, timeout)) {
-   msleep(10);
-   pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, _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)
-- 
2.7.4