Commit 418cb6c8 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Lorenzo Pieralisi
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PCI: hv: Generify PCI probing 

In order to support ARM64 Hyper-V PCI, we need to set up the bridge at
probing time because ARM64 is a PCI_DOMAIN_GENERIC=y arch and we don't
have pci_config_window (ARM64 sysdata) for a PCI root bus on Hyper-V, so
it's impossible to retrieve the information (e.g. PCI domains, MSI
domains) from bus sysdata on ARM64 after creation.

Originally in create_root_hv_pci_bus(), pci_create_root_bus() is used to
create the root bus and the corresponding bridge based on x86 sysdata.
Now we create a bridge first and then call pci_scan_root_bus_bridge(),
which allows us to do the necessary set-ups for the bridge.

Link: https://lore.kernel.org/r/20210726180657.142727-6-boqun.feng@gmail.com


Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
parent 7d40c0f7

drivers/pci/controller/pci-hyperv.c

+30 −27
Original line number Diff line number Diff line
@@ -449,6 +449,7 @@ enum hv_pcibus_state { 


struct hv_pcibus_device {

	struct pci_sysdata sysdata;

	struct pci_host_bridge *bridge;

	/* Protocol version negotiated with the host */

	enum pci_protocol_version_t protocol_version;

	enum hv_pcibus_state state;
@@ -464,8 +465,6 @@ struct hv_pcibus_device { 
	spinlock_t device_list_lock;	/* Protect lists below */

	void __iomem *cfg_addr;



	struct list_head resources_for_children;



	struct list_head children;

	struct list_head dr_list;
@@ -1797,7 +1796,7 @@ static void hv_pci_assign_slots(struct hv_pcibus_device *hbus) 


		slot_nr = PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot));

		snprintf(name, SLOT_NAME_SIZE, "%u", hpdev->desc.ser);

		hpdev->pci_slot = pci_create_slot(hbus->pci_bus, slot_nr,

		hpdev->pci_slot = pci_create_slot(hbus->bridge->bus, slot_nr,

					  name, NULL);

		if (IS_ERR(hpdev->pci_slot)) {

			pr_warn("pci_create slot %s failed\n", name);
@@ -1827,7 +1826,7 @@ static void hv_pci_remove_slots(struct hv_pcibus_device *hbus) 
static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus)

{

	struct pci_dev *dev;

	struct pci_bus *bus = hbus->pci_bus;

	struct pci_bus *bus = hbus->bridge->bus;

	struct hv_pci_dev *hv_dev;



	list_for_each_entry(dev, &bus->devices, bus_list) {
@@ -1850,21 +1849,22 @@ static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus) 
 */

static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)

{

	/* Register the device */

	hbus->pci_bus = pci_create_root_bus(&hbus->hdev->device,

					    0, /* bus number is always zero */

					    &hv_pcifront_ops,

					    &hbus->sysdata,

					    &hbus->resources_for_children);

	if (!hbus->pci_bus)

		return -ENODEV;

	int error;

	struct pci_host_bridge *bridge = hbus->bridge;



	bridge->dev.parent = &hbus->hdev->device;

	bridge->sysdata = &hbus->sysdata;

	bridge->ops = &hv_pcifront_ops;



	error = pci_scan_root_bus_bridge(bridge);

	if (error)

		return error;



	pci_lock_rescan_remove();

	pci_scan_child_bus(hbus->pci_bus);

	hv_pci_assign_numa_node(hbus);

	pci_bus_assign_resources(hbus->pci_bus);

	pci_bus_assign_resources(bridge->bus);

	hv_pci_assign_slots(hbus);

	pci_bus_add_devices(hbus->pci_bus);

	pci_bus_add_devices(bridge->bus);

	pci_unlock_rescan_remove();

	hbus->state = hv_pcibus_installed;

	return 0;
@@ -2127,7 +2127,7 @@ static void pci_devices_present_work(struct work_struct *work) 
		 * because there may have been changes.

		 */

		pci_lock_rescan_remove();

		pci_scan_child_bus(hbus->pci_bus);

		pci_scan_child_bus(hbus->bridge->bus);

		hv_pci_assign_numa_node(hbus);

		hv_pci_assign_slots(hbus);

		pci_unlock_rescan_remove();
@@ -2295,8 +2295,8 @@ static void hv_eject_device_work(struct work_struct *work) 
	/*

	 * Ejection can come before or after the PCI bus has been set up, so

	 * attempt to find it and tear down the bus state, if it exists.  This

	 * must be done without constructs like pci_domain_nr(hbus->pci_bus)

	 * because hbus->pci_bus may not exist yet.

	 * must be done without constructs like pci_domain_nr(hbus->bridge->bus)

	 * because hbus->bridge->bus may not exist yet.

	 */

	wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);

	pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot);
@@ -2662,8 +2662,7 @@ static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus) 
		/* Modify this resource to become a bridge window. */

		hbus->low_mmio_res->flags |= IORESOURCE_WINDOW;

		hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY;

		pci_add_resource(&hbus->resources_for_children,

				 hbus->low_mmio_res);

		pci_add_resource(&hbus->bridge->windows, hbus->low_mmio_res);

	}



	if (hbus->high_mmio_space) {
@@ -2682,8 +2681,7 @@ static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus) 
		/* Modify this resource to become a bridge window. */

		hbus->high_mmio_res->flags |= IORESOURCE_WINDOW;

		hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY;

		pci_add_resource(&hbus->resources_for_children,

				 hbus->high_mmio_res);

		pci_add_resource(&hbus->bridge->windows, hbus->high_mmio_res);

	}



	return 0;
@@ -3002,6 +3000,7 @@ static void hv_put_dom_num(u16 dom) 
static int hv_pci_probe(struct hv_device *hdev,

			const struct hv_vmbus_device_id *dev_id)

{

	struct pci_host_bridge *bridge;

	struct hv_pcibus_device *hbus;

	u16 dom_req, dom;

	char *name;
@@ -3014,6 +3013,10 @@ static int hv_pci_probe(struct hv_device *hdev, 
	 */

	BUILD_BUG_ON(sizeof(*hbus) > HV_HYP_PAGE_SIZE);



	bridge = devm_pci_alloc_host_bridge(&hdev->device, 0);

	if (!bridge)

		return -ENOMEM;



	/*

	 * With the recent 59bb47985c1d ("mm, sl[aou]b: guarantee natural

	 * alignment for kmalloc(power-of-two)"), kzalloc() is able to allocate
@@ -3035,6 +3038,8 @@ static int hv_pci_probe(struct hv_device *hdev, 
	hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);

	if (!hbus)

		return -ENOMEM;



	hbus->bridge = bridge;

	hbus->state = hv_pcibus_init;

	hbus->wslot_res_allocated = -1;
@@ -3071,7 +3076,6 @@ static int hv_pci_probe(struct hv_device *hdev, 
	hbus->hdev = hdev;

	INIT_LIST_HEAD(&hbus->children);

	INIT_LIST_HEAD(&hbus->dr_list);

	INIT_LIST_HEAD(&hbus->resources_for_children);

	spin_lock_init(&hbus->config_lock);

	spin_lock_init(&hbus->device_list_lock);

	spin_lock_init(&hbus->retarget_msi_interrupt_lock);
@@ -3295,9 +3299,9 @@ static int hv_pci_remove(struct hv_device *hdev) 


		/* Remove the bus from PCI's point of view. */

		pci_lock_rescan_remove();

		pci_stop_root_bus(hbus->pci_bus);

		pci_stop_root_bus(hbus->bridge->bus);

		hv_pci_remove_slots(hbus);

		pci_remove_root_bus(hbus->pci_bus);

		pci_remove_root_bus(hbus->bridge->bus);

		pci_unlock_rescan_remove();

	}
@@ -3307,7 +3311,6 @@ static int hv_pci_remove(struct hv_device *hdev) 


	iounmap(hbus->cfg_addr);

	hv_free_config_window(hbus);

	pci_free_resource_list(&hbus->resources_for_children);

	hv_pci_free_bridge_windows(hbus);

	irq_domain_remove(hbus->irq_domain);

	irq_domain_free_fwnode(hbus->sysdata.fwnode);
@@ -3390,7 +3393,7 @@ static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg) 
 */

static void hv_pci_restore_msi_state(struct hv_pcibus_device *hbus)

{

	pci_walk_bus(hbus->pci_bus, hv_pci_restore_msi_msg, NULL);

	pci_walk_bus(hbus->bridge->bus, hv_pci_restore_msi_msg, NULL);

}



static int hv_pci_resume(struct hv_device *hdev)