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Commit 50b52fde authored by Rajat Jain's avatar Rajat Jain Committed by Bjorn Helgaas
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PCI: pciehp: Add hotplug_lock to serialize hotplug events 



Today it is there is no protection around pciehp_enable_slot() and
pciehp_disable_slot() to ensure that they complete before another
hot-plug operation can be done on that particular slot.

This patch introduces the slot->hotplug_lock to ensure that any hotplug
operations (add / remove) complete before another hotplug event can begin
processing on that particular slot.

Signed-off-by: default avatarRajat Jain <rajatxjain@gmail.com>
Signed-off-by: default avatarRajat Jain <rajatjain@juniper.net>
Signed-off-by: default avatarGuenter Roeck <groeck@juniper.net>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent c4f2f5e4

drivers/pci/hotplug/pciehp.h

+1 −0
Original line number Original line Diff line number Diff line
@@ -76,6 +76,7 @@ struct slot { 
	struct hotplug_slot *hotplug_slot;

	struct hotplug_slot *hotplug_slot;

	struct delayed_work work;	/* work for button event */

	struct delayed_work work;	/* work for button event */

	struct mutex lock;

	struct mutex lock;

	struct mutex hotplug_lock;

	struct workqueue_struct *wq;

	struct workqueue_struct *wq;

};

};

drivers/pci/hotplug/pciehp_core.c

+6 −1
Original line number Original line Diff line number Diff line
@@ -283,8 +283,11 @@ static int pciehp_probe(struct pcie_device *dev) 
	slot = ctrl->slot;

	slot = ctrl->slot;

	pciehp_get_adapter_status(slot, &occupied);

	pciehp_get_adapter_status(slot, &occupied);

	pciehp_get_power_status(slot, &poweron);

	pciehp_get_power_status(slot, &poweron);

	if (occupied && pciehp_force)

	if (occupied && pciehp_force) {

		mutex_lock(&slot->hotplug_lock);

		pciehp_enable_slot(slot);

		pciehp_enable_slot(slot);

		mutex_unlock(&slot->hotplug_lock);

	}

	/* If empty slot's power status is on, turn power off */

	/* If empty slot's power status is on, turn power off */

	if (!occupied && poweron && POWER_CTRL(ctrl))

	if (!occupied && poweron && POWER_CTRL(ctrl))

		pciehp_power_off_slot(slot);

		pciehp_power_off_slot(slot);
@@ -328,10 +331,12 @@ static int pciehp_resume (struct pcie_device *dev) 




	/* Check if slot is occupied */

	/* Check if slot is occupied */

	pciehp_get_adapter_status(slot, &status);

	pciehp_get_adapter_status(slot, &status);

	mutex_lock(&slot->hotplug_lock);

	if (status)

	if (status)

		pciehp_enable_slot(slot);

		pciehp_enable_slot(slot);

	else

	else

		pciehp_disable_slot(slot);

		pciehp_disable_slot(slot);

	mutex_unlock(&slot->hotplug_lock);

	return 0;

	return 0;

}

}

#endif /* PM */

#endif /* PM */

drivers/pci/hotplug/pciehp_ctrl.c

+15 −2
Original line number Original line Diff line number Diff line
@@ -293,6 +293,7 @@ static void pciehp_power_thread(struct work_struct *work) 
	struct power_work_info *info =

	struct power_work_info *info =

		container_of(work, struct power_work_info, work);

		container_of(work, struct power_work_info, work);

	struct slot *p_slot = info->p_slot;

	struct slot *p_slot = info->p_slot;

	int ret;





	switch (info->req) {

	switch (info->req) {

	case DISABLE_REQ:

	case DISABLE_REQ:
@@ -300,7 +301,9 @@ static void pciehp_power_thread(struct work_struct *work) 
			 "Disabling domain:bus:device=%04x:%02x:00\n",

			 "Disabling domain:bus:device=%04x:%02x:00\n",

			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),

			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),

			 p_slot->ctrl->pcie->port->subordinate->number);

			 p_slot->ctrl->pcie->port->subordinate->number);

		mutex_lock(&p_slot->hotplug_lock);

		pciehp_disable_slot(p_slot);

		pciehp_disable_slot(p_slot);

		mutex_unlock(&p_slot->hotplug_lock);

		mutex_lock(&p_slot->lock);

		mutex_lock(&p_slot->lock);

		p_slot->state = STATIC_STATE;

		p_slot->state = STATIC_STATE;

		mutex_unlock(&p_slot->lock);

		mutex_unlock(&p_slot->lock);
@@ -310,7 +313,10 @@ static void pciehp_power_thread(struct work_struct *work) 
			 "Enabling domain:bus:device=%04x:%02x:00\n",

			 "Enabling domain:bus:device=%04x:%02x:00\n",

			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),

			 pci_domain_nr(p_slot->ctrl->pcie->port->subordinate),

			 p_slot->ctrl->pcie->port->subordinate->number);

			 p_slot->ctrl->pcie->port->subordinate->number);

		if (pciehp_enable_slot(p_slot))

		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);

			pciehp_green_led_off(p_slot);

		mutex_lock(&p_slot->lock);

		mutex_lock(&p_slot->lock);

		p_slot->state = STATIC_STATE;

		p_slot->state = STATIC_STATE;
@@ -546,6 +552,9 @@ static void interrupt_event_handler(struct work_struct *work) 
	kfree(info);

	kfree(info);

}

}





/*

 * Note: This function must be called with slot->hotplug_lock held

 */

int pciehp_enable_slot(struct slot *p_slot)

int pciehp_enable_slot(struct slot *p_slot)

{

{

	u8 getstatus = 0;

	u8 getstatus = 0;
@@ -584,7 +593,9 @@ int pciehp_enable_slot(struct slot *p_slot) 
	return rc;

	return rc;

}

}







/*

 * Note: This function must be called with slot->hotplug_lock held

 */

int pciehp_disable_slot(struct slot *p_slot)

int pciehp_disable_slot(struct slot *p_slot)

{

{

	u8 getstatus = 0;

	u8 getstatus = 0;
@@ -617,7 +628,9 @@ int pciehp_sysfs_enable_slot(struct slot *p_slot) 
	case STATIC_STATE:

	case STATIC_STATE:

		p_slot->state = POWERON_STATE;

		p_slot->state = POWERON_STATE;

		mutex_unlock(&p_slot->lock);

		mutex_unlock(&p_slot->lock);

		mutex_lock(&p_slot->hotplug_lock);

		retval = pciehp_enable_slot(p_slot);

		retval = pciehp_enable_slot(p_slot);

		mutex_unlock(&p_slot->hotplug_lock);

		mutex_lock(&p_slot->lock);

		mutex_lock(&p_slot->lock);

		p_slot->state = STATIC_STATE;

		p_slot->state = STATIC_STATE;

		break;

		break;

drivers/pci/hotplug/pciehp_hpc.c

+1 −0
Original line number Original line Diff line number Diff line
@@ -686,6 +686,7 @@ static int pcie_init_slot(struct controller *ctrl) 




	slot->ctrl = ctrl;

	slot->ctrl = ctrl;

	mutex_init(&slot->lock);

	mutex_init(&slot->lock);

	mutex_init(&slot->hotplug_lock);

	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);

	INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);

	ctrl->slot = slot;

	ctrl->slot = slot;

	return 0;

	return 0;