Merge branch 'pci/pciehp' into next

* pci/pciehp:
  PCI: pciehp: Cleanup whitespace
  PCI: pciehp: Remove a non-existent card, regardless of "surprise" capability
  PCI: pciehp: Don't turn slot off when hot-added device already exists
  PCI: pciehp: Add hotplug_lock to serialize hotplug events
  PCI: pciehp: Ensure very fast hotplug events are also processed
  PCI: pciehp: Disable link notification across slot reset
  PCI: pciehp: Don't check adapter or latch status while disabling
  PCI: pciehp: Don't disable the link permanently during removal
  PCI: pciehp: Enable link state change notifications
  PCI: pciehp: Use link change notifications for hot-plug and removal
  PCI: pciehp: Make check_link_active() non-static

drivers/pci/hotplug/pciehp.h

@@ -76,6 +76,7 @@ struct slot {
 	struct hotplug_slot *hotplug_slot;
 	struct delayed_work work;	/* work for button event */
 	struct mutex lock;
+	struct mutex hotplug_lock;
 	struct workqueue_struct *wq;
 };
 
@@ -109,6 +110,8 @@ struct controller {
 #define INT_BUTTON_PRESS		7
 #define INT_BUTTON_RELEASE		8
 #define INT_BUTTON_CANCEL		9
+#define INT_LINK_UP			10
+#define INT_LINK_DOWN			11
 
 #define STATIC_STATE			0
 #define BLINKINGON_STATE		1
@@ -132,6 +135,7 @@ u8 pciehp_handle_attention_button(struct slot *p_slot);
 u8 pciehp_handle_switch_change(struct slot *p_slot);
 u8 pciehp_handle_presence_change(struct slot *p_slot);
 u8 pciehp_handle_power_fault(struct slot *p_slot);
+void pciehp_handle_linkstate_change(struct slot *p_slot);
 int pciehp_configure_device(struct slot *p_slot);
 int pciehp_unconfigure_device(struct slot *p_slot);
 void pciehp_queue_pushbutton_work(struct work_struct *work);
@@ -153,6 +157,7 @@ void pciehp_green_led_on(struct slot *slot);
 void pciehp_green_led_off(struct slot *slot);
 void pciehp_green_led_blink(struct slot *slot);
 int pciehp_check_link_status(struct controller *ctrl);
+bool pciehp_check_link_active(struct controller *ctrl);
 void pciehp_release_ctrl(struct controller *ctrl);
 int pciehp_reset_slot(struct slot *slot, int probe);
 

drivers/pci/hotplug/pciehp_acpi.c

@@ -112,6 +112,7 @@ static struct pcie_port_service_driver __initdata dummy_driver = {
 static int __init select_detection_mode(void)
 {
 	struct dummy_slot *slot, *tmp;
+
 	if (pcie_port_service_register(&dummy_driver))
 		return PCIEHP_DETECT_ACPI;
 	pcie_port_service_unregister(&dummy_driver);

drivers/pci/hotplug/pciehp_core.c

@@ -108,6 +108,7 @@ static int init_slot(struct controller *ctrl)
 	ops = kzalloc(sizeof(*ops), GFP_KERNEL);
 	if (!ops)
 		goto out;
+
 	ops->enable_slot = enable_slot;
 	ops->disable_slot = disable_slot;
 	ops->get_power_status = get_power_status;
@@ -283,8 +284,11 @@ static int pciehp_probe(struct pcie_device *dev)
 	slot = ctrl->slot;
 	pciehp_get_adapter_status(slot, &occupied);
 	pciehp_get_power_status(slot, &poweron);
-	if (occupied && pciehp_force)
+	if (occupied && pciehp_force) {
+		mutex_lock(&slot->hotplug_lock);
 		pciehp_enable_slot(slot);
+		mutex_unlock(&slot->hotplug_lock);
+	}
 	/* If empty slot's power status is on, turn power off */
 	if (!occupied && poweron && POWER_CTRL(ctrl))
 		pciehp_power_off_slot(slot);
@@ -328,10 +332,12 @@ static int pciehp_resume (struct pcie_device *dev)
 
 	/* Check if slot is occupied */
 	pciehp_get_adapter_status(slot, &status);
+	mutex_lock(&slot->hotplug_lock);
 	if (status)
 		pciehp_enable_slot(slot);
 	else
 		pciehp_disable_slot(slot);
+	mutex_unlock(&slot->hotplug_lock);
 	return 0;
 }
 #endif /* PM */

drivers/pci/hotplug/pciehp_ctrl.c

@@ -150,6 +150,27 @@ u8 pciehp_handle_power_fault(struct slot *p_slot)
 	return 1;
 }
 
+void pciehp_handle_linkstate_change(struct slot *p_slot)
+{
+	u32 event_type;
+	struct controller *ctrl = p_slot->ctrl;
+
+	/* Link Status Change */
+	ctrl_dbg(ctrl, "Data Link Layer State change\n");
+
+	if (pciehp_check_link_active(ctrl)) {
+		ctrl_info(ctrl, "slot(%s): Link Up event\n",
+			  slot_name(p_slot));
+		event_type = INT_LINK_UP;
+	} else {
+		ctrl_info(ctrl, "slot(%s): Link Down event\n",
+			  slot_name(p_slot));
+		event_type = INT_LINK_DOWN;
+	}
+
+	queue_interrupt_event(p_slot, event_type);
+}
+
 /* The following routines constitute the bulk of the
    hotplug controller logic
  */
@@ -212,7 +233,8 @@ static int board_added(struct slot *p_slot)
 	if (retval) {
 		ctrl_err(ctrl, "Cannot add device at %04x:%02x:00\n",
 			 pci_domain_nr(parent), parent->number);
-		goto err_exit;
+		if (retval != -EEXIST)
+			goto err_exit;
 	}
 
 	pciehp_green_led_on(p_slot);
@@ -255,6 +277,9 @@ static int remove_board(struct slot *p_slot)
 struct power_work_info {
 	struct slot *p_slot;
 	struct work_struct work;
+	unsigned int req;
+#define DISABLE_REQ 0
+#define ENABLE_REQ  1
 };
 
 /**
@@ -269,30 +294,38 @@ static void pciehp_power_thread(struct work_struct *work)
 	struct power_work_info *info =
 		container_of(work, struct power_work_info, work);
 	struct slot *p_slot = info->p_slot;
+	int ret;
 
-	mutex_lock(&p_slot->lock);
-	switch (p_slot->state) {
-	case POWEROFF_STATE:
-		mutex_unlock(&p_slot->lock);
+	switch (info->req) {
+	case DISABLE_REQ:
 		ctrl_dbg(p_slot->ctrl,
 			 "Disabling domain:bus:device=%04x:%02x:00\n",
 			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),
 			 p_slot->ctrl->pcie->port->subordinate->number);
+		mutex_lock(&p_slot->hotplug_lock);
 		pciehp_disable_slot(p_slot);
+		mutex_unlock(&p_slot->hotplug_lock);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
-		break;
-	case POWERON_STATE:
 		mutex_unlock(&p_slot->lock);
-		if (pciehp_enable_slot(p_slot))
+		break;
+	case ENABLE_REQ:
+		ctrl_dbg(p_slot->ctrl,
+			 "Enabling domain:bus:device=%04x:%02x:00\n",
+			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),
+			 p_slot->ctrl->pcie->port->subordinate->number);
+		mutex_lock(&p_slot->hotplug_lock);
+		ret = pciehp_enable_slot(p_slot);
+		mutex_unlock(&p_slot->hotplug_lock);
+		if (ret)
 			pciehp_green_led_off(p_slot);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
+		mutex_unlock(&p_slot->lock);
 		break;
 	default:
 		break;
 	}
-	mutex_unlock(&p_slot->lock);
 
 	kfree(info);
 }
@@ -315,9 +348,11 @@ void pciehp_queue_pushbutton_work(struct work_struct *work)
 	switch (p_slot->state) {
 	case BLINKINGOFF_STATE:
 		p_slot->state = POWEROFF_STATE;
+		info->req = DISABLE_REQ;
 		break;
 	case BLINKINGON_STATE:
 		p_slot->state = POWERON_STATE;
+		info->req = ENABLE_REQ;
 		break;
 	default:
 		kfree(info);
@@ -364,11 +399,10 @@ static void handle_button_press_event(struct slot *p_slot)
 		 */
 		ctrl_info(ctrl, "Button cancel on Slot(%s)\n", slot_name(p_slot));
 		cancel_delayed_work(&p_slot->work);
-		if (p_slot->state == BLINKINGOFF_STATE) {
+		if (p_slot->state == BLINKINGOFF_STATE)
 			pciehp_green_led_on(p_slot);
-		} else {
+		else
 			pciehp_green_led_off(p_slot);
-		}
 		pciehp_set_attention_status(p_slot, 0);
 		ctrl_info(ctrl, "PCI slot #%s - action canceled "
 			  "due to button press\n", slot_name(p_slot));
@@ -407,14 +441,81 @@ static void handle_surprise_event(struct slot *p_slot)
 	INIT_WORK(&info->work, pciehp_power_thread);
 
 	pciehp_get_adapter_status(p_slot, &getstatus);
-	if (!getstatus)
+	if (!getstatus) {
 		p_slot->state = POWEROFF_STATE;
-	else
+		info->req = DISABLE_REQ;
+	} else {
 		p_slot->state = POWERON_STATE;
+		info->req = ENABLE_REQ;
+	}
 
 	queue_work(p_slot->wq, &info->work);
 }
 
+/*
+ * Note: This function must be called with slot->lock held
+ */
+static void handle_link_event(struct slot *p_slot, u32 event)
+{
+	struct controller *ctrl = p_slot->ctrl;
+	struct power_work_info *info;
+
+	info = kmalloc(sizeof(*info), GFP_KERNEL);
+	if (!info) {
+		ctrl_err(p_slot->ctrl, "%s: Cannot allocate memory\n",
+			 __func__);
+		return;
+	}
+	info->p_slot = p_slot;
+	info->req = event == INT_LINK_UP ? ENABLE_REQ : DISABLE_REQ;
+	INIT_WORK(&info->work, pciehp_power_thread);
+
+	switch (p_slot->state) {
+	case BLINKINGON_STATE:
+	case BLINKINGOFF_STATE:
+		cancel_delayed_work(&p_slot->work);
+		/* Fall through */
+	case STATIC_STATE:
+		p_slot->state = event == INT_LINK_UP ?
+		    POWERON_STATE : POWEROFF_STATE;
+		queue_work(p_slot->wq, &info->work);
+		break;
+	case POWERON_STATE:
+		if (event == INT_LINK_UP) {
+			ctrl_info(ctrl,
+				  "Link Up event ignored on slot(%s): already powering on\n",
+				  slot_name(p_slot));
+			kfree(info);
+		} else {
+			ctrl_info(ctrl,
+				  "Link Down event queued on slot(%s): currently getting powered on\n",
+				  slot_name(p_slot));
+			p_slot->state = POWEROFF_STATE;
+			queue_work(p_slot->wq, &info->work);
+		}
+		break;
+	case POWEROFF_STATE:
+		if (event == INT_LINK_UP) {
+			ctrl_info(ctrl,
+				  "Link Up event queued on slot(%s): currently getting powered off\n",
+				  slot_name(p_slot));
+			p_slot->state = POWERON_STATE;
+			queue_work(p_slot->wq, &info->work);
+		} else {
+			ctrl_info(ctrl,
+				  "Link Down event ignored on slot(%s): already powering off\n",
+				  slot_name(p_slot));
+			kfree(info);
+		}
+		break;
+	default:
+		ctrl_err(ctrl, "Not a valid state on slot(%s)\n",
+			 slot_name(p_slot));
+		kfree(info);
+		break;
+	}
+}
+
 static void interrupt_event_handler(struct work_struct *work)
 {
 	struct event_info *info = container_of(work, struct event_info, work);
@@ -433,12 +534,23 @@ static void interrupt_event_handler(struct work_struct *work)
 		pciehp_green_led_off(p_slot);
 		break;
 	case INT_PRESENCE_ON:
-	case INT_PRESENCE_OFF:
 		if (!HP_SUPR_RM(ctrl))
 			break;
+		ctrl_dbg(ctrl, "Surprise Insertion\n");
+		handle_surprise_event(p_slot);
+		break;
+	case INT_PRESENCE_OFF:
+		/*
+		 * Regardless of surprise capability, we need to
+		 * definitely remove a card that has been pulled out!
+		 */
 		ctrl_dbg(ctrl, "Surprise Removal\n");
 		handle_surprise_event(p_slot);
 		break;
+	case INT_LINK_UP:
+	case INT_LINK_DOWN:
+		handle_link_event(p_slot, info->event_type);
+		break;
 	default:
 		break;
 	}
@@ -447,6 +559,9 @@ static void interrupt_event_handler(struct work_struct *work)
 	kfree(info);
 }
 
+/*
+ * Note: This function must be called with slot->hotplug_lock held
+ */
 int pciehp_enable_slot(struct slot *p_slot)
 {
 	u8 getstatus = 0;
@@ -479,13 +594,15 @@ int pciehp_enable_slot(struct slot *p_slot)
 	pciehp_get_latch_status(p_slot, &getstatus);
 
 	rc = board_added(p_slot);
-	if (rc) {
+	if (rc)
 		pciehp_get_latch_status(p_slot, &getstatus);
-	}
+
 	return rc;
 }
 
-
+/*
+ * Note: This function must be called with slot->hotplug_lock held
+ */
 int pciehp_disable_slot(struct slot *p_slot)
 {
 	u8 getstatus = 0;
@@ -494,24 +611,6 @@ int pciehp_disable_slot(struct slot *p_slot)
 	if (!p_slot->ctrl)
 		return 1;
 
-	if (!HP_SUPR_RM(p_slot->ctrl)) {
-		pciehp_get_adapter_status(p_slot, &getstatus);
-		if (!getstatus) {
-			ctrl_info(ctrl, "No adapter on slot(%s)\n",
-				  slot_name(p_slot));
-			return -ENODEV;
-		}
-	}
-
-	if (MRL_SENS(p_slot->ctrl)) {
-		pciehp_get_latch_status(p_slot, &getstatus);
-		if (getstatus) {
-			ctrl_info(ctrl, "Latch open on slot(%s)\n",
-				  slot_name(p_slot));
-			return -ENODEV;
-		}
-	}
-
 	if (POWER_CTRL(p_slot->ctrl)) {
 		pciehp_get_power_status(p_slot, &getstatus);
 		if (!getstatus) {
@@ -536,7 +635,9 @@ int pciehp_sysfs_enable_slot(struct slot *p_slot)
 	case STATIC_STATE:
 		p_slot->state = POWERON_STATE;
 		mutex_unlock(&p_slot->lock);
+		mutex_lock(&p_slot->hotplug_lock);
 		retval = pciehp_enable_slot(p_slot);
+		mutex_unlock(&p_slot->hotplug_lock);
 		mutex_lock(&p_slot->lock);
 		p_slot->state = STATIC_STATE;
 		break;

drivers/pci/hotplug/pciehp_hpc.c

@@ -206,7 +206,7 @@ static void pcie_write_cmd(struct controller *ctrl, u16 cmd, u16 mask)
 	mutex_unlock(&ctrl->ctrl_lock);
 }
 
-static bool check_link_active(struct controller *ctrl)
+bool pciehp_check_link_active(struct controller *ctrl)
 {
 	struct pci_dev *pdev = ctrl_dev(ctrl);
 	u16 lnk_status;
@@ -225,12 +225,12 @@ static void __pcie_wait_link_active(struct controller *ctrl, bool active)
 {
 	int timeout = 1000;
 
-	if (check_link_active(ctrl) == active)
+	if (pciehp_check_link_active(ctrl) == active)
 		return;
 	while (timeout > 0) {
 		msleep(10);
 		timeout -= 10;
-		if (check_link_active(ctrl) == active)
+		if (pciehp_check_link_active(ctrl) == active)
 			return;
 	}
 	ctrl_dbg(ctrl, "Data Link Layer Link Active not %s in 1000 msec\n",
@@ -242,11 +242,6 @@ static void pcie_wait_link_active(struct controller *ctrl)
 	__pcie_wait_link_active(ctrl, true);
 }
 
-static void pcie_wait_link_not_active(struct controller *ctrl)
-{
-	__pcie_wait_link_active(ctrl, false);
-}
-
 static bool pci_bus_check_dev(struct pci_bus *bus, int devfn)
 {
 	u32 l;
@@ -332,11 +327,6 @@ static int pciehp_link_enable(struct controller *ctrl)
 	return __pciehp_link_set(ctrl, true);
 }
 
-static int pciehp_link_disable(struct controller *ctrl)
-{
-	return __pciehp_link_set(ctrl, false);
-}
-
 void pciehp_get_attention_status(struct slot *slot, u8 *status)
 {
 	struct controller *ctrl = slot->ctrl;
@@ -508,14 +498,6 @@ void pciehp_power_off_slot(struct slot * slot)
 {
 	struct controller *ctrl = slot->ctrl;
 
-	/* Disable the link at first */
-	pciehp_link_disable(ctrl);
-	/* wait the link is down */
-	if (ctrl->link_active_reporting)
-		pcie_wait_link_not_active(ctrl);
-	else
-		msleep(1000);
-
 	pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PWR_OFF, PCI_EXP_SLTCTL_PCC);
 	ctrl_dbg(ctrl, "%s: SLOTCTRL %x write cmd %x\n", __func__,
 		 pci_pcie_cap(ctrl->pcie->port) + PCI_EXP_SLTCTL,
@@ -540,7 +522,7 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
 
 		detected &= (PCI_EXP_SLTSTA_ABP | PCI_EXP_SLTSTA_PFD |
 			     PCI_EXP_SLTSTA_MRLSC | PCI_EXP_SLTSTA_PDC |
-			     PCI_EXP_SLTSTA_CC);
+			     PCI_EXP_SLTSTA_CC | PCI_EXP_SLTSTA_DLLSC);
 		detected &= ~intr_loc;
 		intr_loc |= detected;
 		if (!intr_loc)
@@ -579,6 +561,10 @@ static irqreturn_t pcie_isr(int irq, void *dev_id)
 		ctrl->power_fault_detected = 1;
 		pciehp_handle_power_fault(slot);
 	}
+
+	if (intr_loc & PCI_EXP_SLTSTA_DLLSC)
+		pciehp_handle_linkstate_change(slot);
+
 	return IRQ_HANDLED;
 }
 
@@ -596,9 +582,17 @@ void pcie_enable_notification(struct controller *ctrl)
 	 * when it is cleared in the interrupt service routine, and
 	 * next power fault detected interrupt was notified again.
 	 */
-	cmd = PCI_EXP_SLTCTL_PDCE;
+
+	/*
+	 * Always enable link events: thus link-up and link-down shall
+	 * always be treated as hotplug and unplug respectively. Enable
+	 * presence detect only if Attention Button is not present.
+	 */
+	cmd = PCI_EXP_SLTCTL_DLLSCE;
 	if (ATTN_BUTTN(ctrl))
 		cmd |= PCI_EXP_SLTCTL_ABPE;
+	else
+		cmd |= PCI_EXP_SLTCTL_PDCE;
 	if (MRL_SENS(ctrl))
 		cmd |= PCI_EXP_SLTCTL_MRLSCE;
 	if (!pciehp_poll_mode)
@@ -606,7 +600,8 @@ void pcie_enable_notification(struct controller *ctrl)
 
 	mask = (PCI_EXP_SLTCTL_PDCE | PCI_EXP_SLTCTL_ABPE |
 		PCI_EXP_SLTCTL_MRLSCE | PCI_EXP_SLTCTL_PFDE |
-		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE);
+		PCI_EXP_SLTCTL_HPIE | PCI_EXP_SLTCTL_CCIE |
+		PCI_EXP_SLTCTL_DLLSCE);
 
 	pcie_write_cmd(ctrl, cmd, mask);
 }
@@ -624,33 +619,38 @@ static void pcie_disable_notification(struct controller *ctrl)
 
 /*
  * pciehp has a 1:1 bus:slot relationship so we ultimately want a secondary
- * bus reset of the bridge, but if the slot supports surprise removal we need
- * to disable presence detection around the bus reset and clear any spurious
+ * bus reset of the bridge, but at the same time we want to ensure that it is
+ * not seen as a hot-unplug, followed by the hot-plug of the device. Thus,
+ * disable link state notification and presence detection change notification
+ * momentarily, if we see that they could interfere. Also, clear any spurious
  * events after.
  */
 int pciehp_reset_slot(struct slot *slot, int probe)
 {
 	struct controller *ctrl = slot->ctrl;
 	struct pci_dev *pdev = ctrl_dev(ctrl);
+	u16 stat_mask = 0, ctrl_mask = 0;
 
 	if (probe)
 		return 0;
 
-	if (HP_SUPR_RM(ctrl)) {
-		pcie_write_cmd(ctrl, 0, PCI_EXP_SLTCTL_PDCE);
-		if (pciehp_poll_mode)
-			del_timer_sync(&ctrl->poll_timer);
+	if (!ATTN_BUTTN(ctrl)) {
+		ctrl_mask |= PCI_EXP_SLTCTL_PDCE;
+		stat_mask |= PCI_EXP_SLTSTA_PDC;
 	}
+	ctrl_mask |= PCI_EXP_SLTCTL_DLLSCE;
+	stat_mask |= PCI_EXP_SLTSTA_DLLSC;
+
+	pcie_write_cmd(ctrl, 0, ctrl_mask);
+	if (pciehp_poll_mode)
+		del_timer_sync(&ctrl->poll_timer);
 
 	pci_reset_bridge_secondary_bus(ctrl->pcie->port);
 
-	if (HP_SUPR_RM(ctrl)) {
-		pcie_capability_write_word(pdev, PCI_EXP_SLTSTA,
-					   PCI_EXP_SLTSTA_PDC);
-		pcie_write_cmd(ctrl, PCI_EXP_SLTCTL_PDCE, PCI_EXP_SLTCTL_PDCE);
-		if (pciehp_poll_mode)
-			int_poll_timeout(ctrl->poll_timer.data);
-	}
+	pcie_capability_write_word(pdev, PCI_EXP_SLTSTA, stat_mask);
+	pcie_write_cmd(ctrl, ctrl_mask, ctrl_mask);
+	if (pciehp_poll_mode)
+		int_poll_timeout(ctrl->poll_timer.data);
 
 	return 0;
 }
@@ -687,6 +687,7 @@ static int pcie_init_slot(struct controller *ctrl)
 
 	slot->ctrl = ctrl;
 	mutex_init(&slot->lock);
+	mutex_init(&slot->hotplug_lock);
 	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
 	ctrl->slot = slot;
 	return 0;

drivers/pci/hotplug/pciehp_pci.c

@@ -50,7 +50,7 @@ int pciehp_configure_device(struct slot *p_slot)
 			 "at %04x:%02x:00, cannot hot-add\n", pci_name(dev),
 			 pci_domain_nr(parent), parent->number);
 		pci_dev_put(dev);
-		ret = -EINVAL;
+		ret = -EEXIST;
 		goto out;
 	}