Merge branch 'pci/hotplug'

- Fix infinite loop in pciehp IRQ handler on power fault (Lukas Wunner)

- Removed commented-out ibmphp functions (Vihas Mak)

- Fix pciehp lockdep errors on Thunderbolt undock (Hans de Goede)

* pci/hotplug:
  PCI: pciehp: Use down_read/write_nested(reset_lock) to fix lockdep errors
  PCI: ibmphp: Remove commented-out functions
  PCI: pciehp: Fix infinite loop in IRQ handler upon power fault

Author: bjorn-helgaas

drivers/pci/hotplug/TODO

@@ -30,11 +30,6 @@ ibmphp:
   or ibmphp should store a pointer to its bus in struct slot.  Probably the
   former.
 
-* The functions get_max_adapter_speed() and get_bus_name() are commented out.
-  Can they be deleted?  There are also forward declarations at the top of
-  ibmphp_core.c as well as pointers in ibmphp_hotplug_slot_ops, likewise
-  commented out.
-
 * ibmphp_init_devno() takes a struct slot **, it could instead take a
   struct slot *.
 

drivers/pci/hotplug/ibmphp_core.c

@@ -50,14 +50,6 @@ static int irqs[16];    /* PIC mode IRQs we're using so far (in case MPS
 
 static int init_flag;
 
-/*
-static int get_max_adapter_speed_1 (struct hotplug_slot *, u8 *, u8);
-
-static inline int get_max_adapter_speed (struct hotplug_slot *hs, u8 *value)
-{
-	return get_max_adapter_speed_1 (hs, value, 1);
-}
-*/
 static inline int get_cur_bus_info(struct slot **sl)
 {
 	int rc = 1;
@@ -401,69 +393,6 @@ static int get_max_bus_speed(struct slot *slot)
 	return rc;
 }
 
-/*
-static int get_max_adapter_speed_1(struct hotplug_slot *hotplug_slot, u8 *value, u8 flag)
-{
-	int rc = -ENODEV;
-	struct slot *pslot;
-	struct slot myslot;
-
-	debug("get_max_adapter_speed_1 - Entry hotplug_slot[%lx] pvalue[%lx]\n",
-						(ulong)hotplug_slot, (ulong) value);
-
-	if (flag)
-		ibmphp_lock_operations();
-
-	if (hotplug_slot && value) {
-		pslot = hotplug_slot->private;
-		if (pslot) {
-			memcpy(&myslot, pslot, sizeof(struct slot));
-			rc = ibmphp_hpc_readslot(pslot, READ_SLOTSTATUS,
-						&(myslot.status));
-
-			if (!(SLOT_LATCH (myslot.status)) &&
-					(SLOT_PRESENT (myslot.status))) {
-				rc = ibmphp_hpc_readslot(pslot,
-						READ_EXTSLOTSTATUS,
-						&(myslot.ext_status));
-				if (!rc)
-					*value = SLOT_SPEED(myslot.ext_status);
-			} else
-				*value = MAX_ADAPTER_NONE;
-		}
-	}
-
-	if (flag)
-		ibmphp_unlock_operations();
-
-	debug("get_max_adapter_speed_1 - Exit rc[%d] value[%x]\n", rc, *value);
-	return rc;
-}
-
-static int get_bus_name(struct hotplug_slot *hotplug_slot, char *value)
-{
-	int rc = -ENODEV;
-	struct slot *pslot = NULL;
-
-	debug("get_bus_name - Entry hotplug_slot[%lx]\n", (ulong)hotplug_slot);
-
-	ibmphp_lock_operations();
-
-	if (hotplug_slot) {
-		pslot = hotplug_slot->private;
-		if (pslot) {
-			rc = 0;
-			snprintf(value, 100, "Bus %x", pslot->bus);
-		}
-	} else
-		rc = -ENODEV;
-
-	ibmphp_unlock_operations();
-	debug("get_bus_name - Exit rc[%d] value[%x]\n", rc, *value);
-	return rc;
-}
-*/
-
 /****************************************************************************
  * This routine will initialize the ops data structure used in the validate
  * function. It will also power off empty slots that are powered on since BIOS
@@ -1231,9 +1160,6 @@ const struct hotplug_slot_ops ibmphp_hotplug_slot_ops = {
 	.get_attention_status =		get_attention_status,
 	.get_latch_status =		get_latch_status,
 	.get_adapter_status =		get_adapter_present,
-/*	.get_max_adapter_speed =	get_max_adapter_speed,
-	.get_bus_name_status =		get_bus_name,
-*/
 };
 
 static void ibmphp_unload(void)

drivers/pci/hotplug/pciehp.h

@@ -75,6 +75,8 @@ extern int pciehp_poll_time;
  * @reset_lock: prevents access to the Data Link Layer Link Active bit in the
  *	Link Status register and to the Presence Detect State bit in the Slot
  *	Status register during a slot reset which may cause them to flap
+ * @depth: Number of additional hotplug ports in the path to the root bus,
+ *	used as lock subclass for @reset_lock
  * @ist_running: flag to keep user request waiting while IRQ thread is running
  * @request_result: result of last user request submitted to the IRQ thread
  * @requester: wait queue to wake up on completion of user request,
@@ -106,6 +108,7 @@ struct controller {
 
 	struct hotplug_slot hotplug_slot;	/* hotplug core interface */
 	struct rw_semaphore reset_lock;
+	unsigned int depth;
 	unsigned int ist_running;
 	int request_result;
 	wait_queue_head_t requester;

drivers/pci/hotplug/pciehp_core.c

@@ -166,7 +166,7 @@ static void pciehp_check_presence(struct controller *ctrl)
 {
 	int occupied;
 
-	down_read(&ctrl->reset_lock);
+	down_read_nested(&ctrl->reset_lock, ctrl->depth);
 	mutex_lock(&ctrl->state_lock);
 
 	occupied = pciehp_card_present_or_link_active(ctrl);

drivers/pci/hotplug/pciehp_hpc.c

@@ -583,7 +583,7 @@ static void pciehp_ignore_dpc_link_change(struct controller *ctrl,
 	 * the corresponding link change may have been ignored above.
 	 * Synthesize it to ensure that it is acted on.
 	 */
-	down_read(&ctrl->reset_lock);
+	down_read_nested(&ctrl->reset_lock, ctrl->depth);
 	if (!pciehp_check_link_active(ctrl))
 		pciehp_request(ctrl, PCI_EXP_SLTSTA_DLLSC);
 	up_read(&ctrl->reset_lock);
@@ -642,6 +642,8 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
 	 */
 	if (ctrl->power_fault_detected)
 		status &= ~PCI_EXP_SLTSTA_PFD;
+	else if (status & PCI_EXP_SLTSTA_PFD)
+		ctrl->power_fault_detected = true;
 
 	events |= status;
 	if (!events) {
@@ -651,7 +653,7 @@ static irqreturn_t pciehp_isr(int irq, void *dev_id)
 	}
 
 	if (status) {
-		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, events);
+		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, status);
 
 		/*
 		 * In MSI mode, all event bits must be zero before the port
@@ -725,8 +727,7 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
 	}
 
 	/* Check Power Fault Detected */
-	if ((events & PCI_EXP_SLTSTA_PFD) && !ctrl->power_fault_detected) {
-		ctrl->power_fault_detected = 1;
+	if (events & PCI_EXP_SLTSTA_PFD) {
 		ctrl_err(ctrl, "Slot(%s): Power fault\n", slot_name(ctrl));
 		pciehp_set_indicators(ctrl, PCI_EXP_SLTCTL_PWR_IND_OFF,
 				      PCI_EXP_SLTCTL_ATTN_IND_ON);
@@ -746,7 +747,7 @@ static irqreturn_t pciehp_ist(int irq, void *dev_id)
 	 * Disable requests have higher priority than Presence Detect Changed
 	 * or Data Link Layer State Changed events.
 	 */
-	down_read(&ctrl->reset_lock);
+	down_read_nested(&ctrl->reset_lock, ctrl->depth);
 	if (events & DISABLE_SLOT)
 		pciehp_handle_disable_request(ctrl);
 	else if (events & (PCI_EXP_SLTSTA_PDC | PCI_EXP_SLTSTA_DLLSC))
@@ -906,7 +907,7 @@ int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
 	if (probe)
 		return 0;
 
-	down_write(&ctrl->reset_lock);
+	down_write_nested(&ctrl->reset_lock, ctrl->depth);
 
 	if (!ATTN_BUTTN(ctrl)) {
 		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
@@ -962,6 +963,20 @@ static inline void dbg_ctrl(struct controller *ctrl)
 
 #define FLAG(x, y)	(((x) & (y)) ? '+' : '-')
 
+static inline int pcie_hotplug_depth(struct pci_dev *dev)
+{
+	struct pci_bus *bus = dev->bus;
+	int depth = 0;
+
+	while (bus->parent) {
+		bus = bus->parent;
+		if (bus->self && bus->self->is_hotplug_bridge)
+			depth++;
+	}
+
+	return depth;
+}
+
 struct controller *pcie_init(struct pcie_device *dev)
 {
 	struct controller *ctrl;
@@ -975,6 +990,7 @@ struct controller *pcie_init(struct pcie_device *dev)
 		return NULL;
 
 	ctrl->pcie = dev;
+	ctrl->depth = pcie_hotplug_depth(dev->port);
 	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
 
 	if (pdev->hotplug_user_indicators)