Commit 375553a9 authored by Shanker Donthineni's avatar Shanker Donthineni Committed by Bjorn Helgaas
Browse files

PCI: Setup ACPI fwnode early and at the same time with OF 

Previously, the ACPI_COMPANION() of a pci_dev was usually set by
acpi_bind_one() in this path:

  pci_device_add
    pci_configure_device
    pci_init_capabilities
    device_add
      device_platform_notify
	acpi_platform_notify
	  acpi_device_notify  # KOBJ_ADD
	    acpi_bind_one
	      ACPI_COMPANION_SET

However, things like pci_configure_device() and pci_init_capabilities()
that run before device_add() need the ACPI_COMPANION, e.g.,
acpi_pci_bridge_d3() uses a _DSD method to learn about D3 support.  These
places had special-case code to manually look up the ACPI_COMPANION.

Set the ACPI_COMPANION earlier, in pci_setup_device(), so it will be
available while configuring the device.  This covers both paths to creating
pci_dev objects:

  pci_scan_single_device           # for normal non-SR-IOV devices
    pci_scan_device
      pci_setup_device
	pci_set_acpi_fwnode
    pci_device_add

  pci_iov_add_virtfn               # for SR-IOV virtual functions
    pci_setup_device
      pci_set_acpi_fwnode

Also move the OF fwnode setup to the same spot.

[bhelgaas: commit log]
Link: https://lore.kernel.org/r/20210817180500.1253-8-ameynarkhede03@gmail.com


Signed-off-by: default avatarShanker Donthineni <sdonthineni@nvidia.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 4273e64c

drivers/pci/pci-acpi.c

+12 −22
Original line number Diff line number Diff line
@@ -952,46 +952,36 @@ static bool acpi_pci_power_manageable(struct pci_dev *dev) 


static bool acpi_pci_bridge_d3(struct pci_dev *dev)

{

	const struct fwnode_handle *fwnode;

	const union acpi_object *obj;

	struct acpi_device *adev;

	struct pci_dev *root;

	u8 val;

	struct pci_dev *rpdev;



	if (!dev->is_hotplug_bridge)

		return false;



	/* Assume D3 support if the bridge is power-manageable by ACPI. */

	pci_set_acpi_fwnode(dev);



	if (acpi_pci_power_manageable(dev))

		return true;



	/*

	 * Look for a special _DSD property for the root port and if it

	 * is set we know the hierarchy behind it supports D3 just fine.

	 * The ACPI firmware will provide the device-specific properties through

	 * _DSD configuration object. Look for the 'HotPlugSupportInD3' property

	 * for the root port and if it is set we know the hierarchy behind it

	 * supports D3 just fine.

	 */

	root = pcie_find_root_port(dev);

	if (!root)

	rpdev = pcie_find_root_port(dev);

	if (!rpdev)

		return false;



	adev = ACPI_COMPANION(&root->dev);

	if (root == dev) {

		/*

		 * It is possible that the ACPI companion is not yet bound

		 * for the root port so look it up manually here.

		 */

		if (!adev && !pci_dev_is_added(root))

			adev = acpi_pci_find_companion(&root->dev);

	}



	adev = ACPI_COMPANION(&rpdev->dev);

	if (!adev)

		return false;



	fwnode = acpi_fwnode_handle(adev);

	if (fwnode_property_read_u8(fwnode, "HotPlugSupportInD3", &val))

	if (acpi_dev_get_property(adev, "HotPlugSupportInD3",

				   ACPI_TYPE_INTEGER, &obj) < 0)

		return false;



	return val == 1;

	return obj->integer.value == 1;

}



static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)

drivers/pci/probe.c

+4 −3
Original line number Diff line number Diff line
@@ -1810,6 +1810,9 @@ int pci_setup_device(struct pci_dev *dev) 
	dev->error_state = pci_channel_io_normal;

	set_pcie_port_type(dev);



	pci_set_of_node(dev);

	pci_set_acpi_fwnode(dev);



	pci_dev_assign_slot(dev);



	/*
@@ -1947,6 +1950,7 @@ int pci_setup_device(struct pci_dev *dev) 
	default:				    /* unknown header */

		pci_err(dev, "unknown header type %02x, ignoring device\n",

			dev->hdr_type);

		pci_release_of_node(dev);

		return -EIO;



	bad:
@@ -2375,10 +2379,7 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) 
	dev->vendor = l & 0xffff;

	dev->device = (l >> 16) & 0xffff;



	pci_set_of_node(dev);



	if (pci_setup_device(dev)) {

		pci_release_of_node(dev);

		pci_bus_put(dev->bus);

		kfree(dev);

		return NULL;