Commit 741f8e7e authored by Bjorn Helgaas's avatar Bjorn Helgaas
Browse files

Merge branch 'lorenzo/pci/hv' 

  - fix Hyper-V bus registration failure caused by domain/serial number
    confusion (Sridhar Pitchai)

  - improve Hyper-V refcounting and coding style (Stephen Hemminger)

  - avoid potential Hyper-V hang waiting for a response that will never
    come (Dexuan Cui)

* lorenzo/pci/hv:
  PCI: hv: Do not wait forever on a device that has disappeared
  PCI: hv: Use list_for_each_entry()
  PCI: hv: Convert remove_lock to refcount
  PCI: hv: Remove unused reason for refcount handler
  PCI: hv: Make sure the bus domain is really unique
parents 5db844ee c3635da2

drivers/pci/host/pci-hyperv.c

+71 −91
Original line number Diff line number Diff line
@@ -433,7 +433,7 @@ enum hv_pcibus_state { 
struct hv_pcibus_device {

	struct pci_sysdata sysdata;

	enum hv_pcibus_state state;

	atomic_t remove_lock;

	refcount_t remove_lock;

	struct hv_device *hdev;

	resource_size_t low_mmio_space;

	resource_size_t high_mmio_space;
@@ -488,17 +488,6 @@ enum hv_pcichild_state { 
	hv_pcichild_maximum

};



enum hv_pcidev_ref_reason {

	hv_pcidev_ref_invalid = 0,

	hv_pcidev_ref_initial,

	hv_pcidev_ref_by_slot,

	hv_pcidev_ref_packet,

	hv_pcidev_ref_pnp,

	hv_pcidev_ref_childlist,

	hv_pcidev_irqdata,

	hv_pcidev_ref_max

};



struct hv_pci_dev {

	/* List protected by pci_rescan_remove_lock */

	struct list_head list_entry;
@@ -548,14 +537,41 @@ static void hv_pci_generic_compl(void *context, struct pci_response *resp, 


static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,

						u32 wslot);

static void get_pcichild(struct hv_pci_dev *hv_pcidev,

			 enum hv_pcidev_ref_reason reason);

static void put_pcichild(struct hv_pci_dev *hv_pcidev,

			 enum hv_pcidev_ref_reason reason);



static void get_pcichild(struct hv_pci_dev *hpdev)

{

	refcount_inc(&hpdev->refs);

}



static void put_pcichild(struct hv_pci_dev *hpdev)

{

	if (refcount_dec_and_test(&hpdev->refs))

		kfree(hpdev);

}



static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus);

static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus);



/*

 * There is no good way to get notified from vmbus_onoffer_rescind(),

 * so let's use polling here, since this is not a hot path.

 */

static int wait_for_response(struct hv_device *hdev,

			     struct completion *comp)

{

	while (true) {

		if (hdev->channel->rescind) {

			dev_warn_once(&hdev->device, "The device is gone.\n");

			return -ENODEV;

		}



		if (wait_for_completion_timeout(comp, HZ / 10))

			break;

	}



	return 0;

}



/**

 * devfn_to_wslot() - Convert from Linux PCI slot to Windows

 * @devfn:	The Linux representation of PCI slot
@@ -762,7 +778,7 @@ static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn, 


	_hv_pcifront_read_config(hpdev, where, size, val);



	put_pcichild(hpdev, hv_pcidev_ref_by_slot);

	put_pcichild(hpdev);

	return PCIBIOS_SUCCESSFUL;

}
@@ -790,7 +806,7 @@ static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn, 


	_hv_pcifront_write_config(hpdev, where, size, val);



	put_pcichild(hpdev, hv_pcidev_ref_by_slot);

	put_pcichild(hpdev);

	return PCIBIOS_SUCCESSFUL;

}
@@ -856,7 +872,7 @@ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info, 
	}



	hv_int_desc_free(hpdev, int_desc);

	put_pcichild(hpdev, hv_pcidev_ref_by_slot);

	put_pcichild(hpdev);

}



static int hv_set_affinity(struct irq_data *data, const struct cpumask *dest,
@@ -1186,13 +1202,13 @@ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) 
	msg->address_lo = comp.int_desc.address & 0xffffffff;

	msg->data = comp.int_desc.data;



	put_pcichild(hpdev, hv_pcidev_ref_by_slot);

	put_pcichild(hpdev);

	return;



free_int_desc:

	kfree(int_desc);

drop_reference:

	put_pcichild(hpdev, hv_pcidev_ref_by_slot);

	put_pcichild(hpdev);

return_null_message:

	msg->address_hi = 0;

	msg->address_lo = 0;
@@ -1283,7 +1299,6 @@ static u64 get_bar_size(u64 bar_val) 
 */

static void survey_child_resources(struct hv_pcibus_device *hbus)

{

	struct list_head *iter;

	struct hv_pci_dev *hpdev;

	resource_size_t bar_size = 0;

	unsigned long flags;
@@ -1309,8 +1324,7 @@ static void survey_child_resources(struct hv_pcibus_device *hbus) 
	 * for a child device are a power of 2 in size and aligned in memory,

	 * so it's sufficient to just add them up without tracking alignment.

	 */

	list_for_each(iter, &hbus->children) {

		hpdev = container_of(iter, struct hv_pci_dev, list_entry);

	list_for_each_entry(hpdev, &hbus->children, list_entry) {

		for (i = 0; i < 6; i++) {

			if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO)

				dev_err(&hbus->hdev->device,
@@ -1363,7 +1377,6 @@ static void prepopulate_bars(struct hv_pcibus_device *hbus) 
	resource_size_t low_base = 0;

	resource_size_t bar_size;

	struct hv_pci_dev *hpdev;

	struct list_head *iter;

	unsigned long flags;

	u64 bar_val;

	u32 command;
@@ -1385,9 +1398,7 @@ static void prepopulate_bars(struct hv_pcibus_device *hbus) 


	/* Pick addresses for the BARs. */

	do {

		list_for_each(iter, &hbus->children) {

			hpdev = container_of(iter, struct hv_pci_dev,

					     list_entry);

		list_for_each_entry(hpdev, &hbus->children, list_entry) {

			for (i = 0; i < 6; i++) {

				bar_val = hpdev->probed_bar[i];

				if (bar_val == 0)
@@ -1508,19 +1519,6 @@ static void q_resource_requirements(void *context, struct pci_response *resp, 
	complete(&completion->host_event);

}



static void get_pcichild(struct hv_pci_dev *hpdev,

			    enum hv_pcidev_ref_reason reason)

{

	refcount_inc(&hpdev->refs);

}



static void put_pcichild(struct hv_pci_dev *hpdev,

			    enum hv_pcidev_ref_reason reason)

{

	if (refcount_dec_and_test(&hpdev->refs))

		kfree(hpdev);

}



/**

 * new_pcichild_device() - Create a new child device

 * @hbus:	The internal struct tracking this root PCI bus.
@@ -1568,24 +1566,14 @@ static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus, 
	if (ret)

		goto error;



	wait_for_completion(&comp_pkt.host_event);

	if (wait_for_response(hbus->hdev, &comp_pkt.host_event))

		goto error;



	hpdev->desc = *desc;

	refcount_set(&hpdev->refs, 1);

	get_pcichild(hpdev, hv_pcidev_ref_childlist);

	get_pcichild(hpdev);

	spin_lock_irqsave(&hbus->device_list_lock, flags);



	/*

	 * When a device is being added to the bus, we set the PCI domain

	 * number to be the device serial number, which is non-zero and

	 * unique on the same VM.  The serial numbers start with 1, and

	 * increase by 1 for each device.  So device names including this

	 * can have shorter names than based on the bus instance UUID.

	 * Only the first device serial number is used for domain, so the

	 * domain number will not change after the first device is added.

	 */

	if (list_empty(&hbus->children))

		hbus->sysdata.domain = desc->ser;

	list_add_tail(&hpdev->list_entry, &hbus->children);

	spin_unlock_irqrestore(&hbus->device_list_lock, flags);

	return hpdev;
@@ -1618,7 +1606,7 @@ static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, 
	list_for_each_entry(iter, &hbus->children, list_entry) {

		if (iter->desc.win_slot.slot == wslot) {

			hpdev = iter;

			get_pcichild(hpdev, hv_pcidev_ref_by_slot);

			get_pcichild(hpdev);

			break;

		}

	}
@@ -1654,7 +1642,6 @@ static void pci_devices_present_work(struct work_struct *work) 
{

	u32 child_no;

	bool found;

	struct list_head *iter;

	struct pci_function_description *new_desc;

	struct hv_pci_dev *hpdev;

	struct hv_pcibus_device *hbus;
@@ -1691,9 +1678,7 @@ static void pci_devices_present_work(struct work_struct *work) 


	/* First, mark all existing children as reported missing. */

	spin_lock_irqsave(&hbus->device_list_lock, flags);

	list_for_each(iter, &hbus->children) {

			hpdev = container_of(iter, struct hv_pci_dev,

					     list_entry);

	list_for_each_entry(hpdev, &hbus->children, list_entry) {

		hpdev->reported_missing = true;

	}

	spin_unlock_irqrestore(&hbus->device_list_lock, flags);
@@ -1704,11 +1689,8 @@ static void pci_devices_present_work(struct work_struct *work) 
		new_desc = &dr->func[child_no];



		spin_lock_irqsave(&hbus->device_list_lock, flags);

		list_for_each(iter, &hbus->children) {

			hpdev = container_of(iter, struct hv_pci_dev,

					     list_entry);

			if ((hpdev->desc.win_slot.slot ==

			     new_desc->win_slot.slot) &&

		list_for_each_entry(hpdev, &hbus->children, list_entry) {

			if ((hpdev->desc.win_slot.slot == new_desc->win_slot.slot) &&

			    (hpdev->desc.v_id == new_desc->v_id) &&

			    (hpdev->desc.d_id == new_desc->d_id) &&

			    (hpdev->desc.ser == new_desc->ser)) {
@@ -1730,12 +1712,10 @@ static void pci_devices_present_work(struct work_struct *work) 
	spin_lock_irqsave(&hbus->device_list_lock, flags);

	do {

		found = false;

		list_for_each(iter, &hbus->children) {

			hpdev = container_of(iter, struct hv_pci_dev,

					     list_entry);

		list_for_each_entry(hpdev, &hbus->children, list_entry) {

			if (hpdev->reported_missing) {

				found = true;

				put_pcichild(hpdev, hv_pcidev_ref_childlist);

				put_pcichild(hpdev);

				list_move_tail(&hpdev->list_entry, &removed);

				break;

			}
@@ -1748,7 +1728,7 @@ static void pci_devices_present_work(struct work_struct *work) 
		hpdev = list_first_entry(&removed, struct hv_pci_dev,

					 list_entry);

		list_del(&hpdev->list_entry);

		put_pcichild(hpdev, hv_pcidev_ref_initial);

		put_pcichild(hpdev);

	}



	switch (hbus->state) {
@@ -1883,8 +1863,8 @@ static void hv_eject_device_work(struct work_struct *work) 
			 sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,

			 VM_PKT_DATA_INBAND, 0);



	put_pcichild(hpdev, hv_pcidev_ref_childlist);

	put_pcichild(hpdev, hv_pcidev_ref_pnp);

	put_pcichild(hpdev);

	put_pcichild(hpdev);

	put_hvpcibus(hpdev->hbus);

}
@@ -1899,7 +1879,7 @@ static void hv_eject_device_work(struct work_struct *work) 
static void hv_pci_eject_device(struct hv_pci_dev *hpdev)

{

	hpdev->state = hv_pcichild_ejecting;

	get_pcichild(hpdev, hv_pcidev_ref_pnp);

	get_pcichild(hpdev);

	INIT_WORK(&hpdev->wrk, hv_eject_device_work);

	get_hvpcibus(hpdev->hbus);

	queue_work(hpdev->hbus->wq, &hpdev->wrk);
@@ -1999,8 +1979,7 @@ static void hv_pci_onchannelcallback(void *context) 
						      dev_message->wslot.slot);

				if (hpdev) {

					hv_pci_eject_device(hpdev);

					put_pcichild(hpdev,

							hv_pcidev_ref_by_slot);

					put_pcichild(hpdev);

				}

				break;
@@ -2069,15 +2048,16 @@ static int hv_pci_protocol_negotiation(struct hv_device *hdev) 
				sizeof(struct pci_version_request),

				(unsigned long)pkt, VM_PKT_DATA_INBAND,

				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

		if (!ret)

			ret = wait_for_response(hdev, &comp_pkt.host_event);



		if (ret) {

			dev_err(&hdev->device,

				"PCI Pass-through VSP failed sending version reqquest: %#x",

				"PCI Pass-through VSP failed to request version: %d",

				ret);

			goto exit;

		}



		wait_for_completion(&comp_pkt.host_event);



		if (comp_pkt.completion_status >= 0) {

			pci_protocol_version = pci_protocol_versions[i];

			dev_info(&hdev->device,
@@ -2286,11 +2266,12 @@ static int hv_pci_enter_d0(struct hv_device *hdev) 
	ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry),

			       (unsigned long)pkt, VM_PKT_DATA_INBAND,

			       VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

	if (!ret)

		ret = wait_for_response(hdev, &comp_pkt.host_event);



	if (ret)

		goto exit;



	wait_for_completion(&comp_pkt.host_event);



	if (comp_pkt.completion_status < 0) {

		dev_err(&hdev->device,

			"PCI Pass-through VSP failed D0 Entry with status %x\n",
@@ -2330,11 +2311,10 @@ static int hv_pci_query_relations(struct hv_device *hdev) 


	ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message),

			       0, VM_PKT_DATA_INBAND, 0);

	if (ret)

		return ret;

	if (!ret)

		ret = wait_for_response(hdev, &comp);



	wait_for_completion(&comp);

	return 0;

	return ret;

}



/**
@@ -2398,17 +2378,17 @@ static int hv_send_resources_allocated(struct hv_device *hdev) 
				PCI_RESOURCES_ASSIGNED2;

			res_assigned2->wslot.slot = hpdev->desc.win_slot.slot;

		}

		put_pcichild(hpdev, hv_pcidev_ref_by_slot);

		put_pcichild(hpdev);



		ret = vmbus_sendpacket(hdev->channel, &pkt->message,

				size_res, (unsigned long)pkt,

				VM_PKT_DATA_INBAND,

				VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);

		if (!ret)

			ret = wait_for_response(hdev, &comp_pkt.host_event);

		if (ret)

			break;



		wait_for_completion(&comp_pkt.host_event);



		if (comp_pkt.completion_status < 0) {

			ret = -EPROTO;

			dev_err(&hdev->device,
@@ -2446,7 +2426,7 @@ static int hv_send_resources_released(struct hv_device *hdev) 
		pkt.message_type.type = PCI_RESOURCES_RELEASED;

		pkt.wslot.slot = hpdev->desc.win_slot.slot;



		put_pcichild(hpdev, hv_pcidev_ref_by_slot);

		put_pcichild(hpdev);



		ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0,

				       VM_PKT_DATA_INBAND, 0);
@@ -2459,12 +2439,12 @@ static int hv_send_resources_released(struct hv_device *hdev) 


static void get_hvpcibus(struct hv_pcibus_device *hbus)

{

	atomic_inc(&hbus->remove_lock);

	refcount_inc(&hbus->remove_lock);

}



static void put_hvpcibus(struct hv_pcibus_device *hbus)

{

	if (atomic_dec_and_test(&hbus->remove_lock))

	if (refcount_dec_and_test(&hbus->remove_lock))

		complete(&hbus->remove_event);

}
@@ -2508,7 +2488,7 @@ static int hv_pci_probe(struct hv_device *hdev, 
			       hdev->dev_instance.b[8] << 8;



	hbus->hdev = hdev;

	atomic_inc(&hbus->remove_lock);

	refcount_set(&hbus->remove_lock, 1);

	INIT_LIST_HEAD(&hbus->children);

	INIT_LIST_HEAD(&hbus->dr_list);

	INIT_LIST_HEAD(&hbus->resources_for_children);

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