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PCI: hv: Generify PCI probing
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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/[email protected]
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
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@arndb
arndb authored and Lorenzo Pieralisi committed Aug 23, 2021
1 parent 7d40c0f commit 418cb6c
Showing 1 changed file with 30 additions and 27 deletions.
57 changes: 30 additions & 27 deletions drivers/pci/controller/pci-hyperv.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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;

Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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) {
Expand All @@ -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;
Expand Down Expand Up @@ -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();
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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) {
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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
Expand All @@ -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;

Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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();
}

Expand All @@ -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);
Expand Down Expand Up @@ -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)
Expand Down

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