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Commit 2f7bbceb authored by Alexander Chiang's avatar Alexander Chiang Committed by Len Brown
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ACPI: Introduce acpi_get_pci_dev()



Convert an ACPI CA handle to a struct pci_dev.

Performing this lookup dynamically allows us to get rid of the
ACPI-PCI binding code, which:

	- eliminates struct acpi_device vs struct pci_dev lifetime issues
	- lays more groundwork for eliminating .start from acpi_device_ops
	  and thus simplifying ACPI drivers
	- whacks out a lot of code

This change lays the groundwork for eliminating much of pci_bind.c.

Although pci_root.c may not be the most logical place for this
change, putting it here saves us from having to export acpi_pci_find_root.

Signed-off-by: default avatarAlex Chiang <achiang@hp.com>
Acked-by: default avatarBjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 27558203
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+81 −0
Original line number Original line Diff line number Diff line
@@ -329,6 +329,87 @@ static struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
	return NULL;
	return NULL;
}
}


struct acpi_handle_node {
	struct list_head node;
	acpi_handle handle;
};

/**
 * acpi_get_pci_dev - convert ACPI CA handle to struct pci_dev
 * @handle: the handle in question
 *
 * Given an ACPI CA handle, the desired PCI device is located in the
 * list of PCI devices.
 *
 * If the device is found, its reference count is increased and this
 * function returns a pointer to its data structure.  The caller must
 * decrement the reference count by calling pci_dev_put().
 * If no device is found, %NULL is returned.
 */
struct pci_dev *acpi_get_pci_dev(acpi_handle handle)
{
	int dev, fn;
	unsigned long long adr;
	acpi_status status;
	acpi_handle phandle;
	struct pci_bus *pbus;
	struct pci_dev *pdev = NULL;
	struct acpi_handle_node *node, *tmp;
	struct acpi_pci_root *root;
	LIST_HEAD(device_list);

	/*
	 * Walk up the ACPI CA namespace until we reach a PCI root bridge.
	 */
	phandle = handle;
	while (!acpi_is_root_bridge(phandle)) {
		node = kzalloc(sizeof(struct acpi_handle_node), GFP_KERNEL);
		if (!node)
			goto out;

		INIT_LIST_HEAD(&node->node);
		node->handle = phandle;
		list_add(&node->node, &device_list);

		status = acpi_get_parent(phandle, &phandle);
		if (ACPI_FAILURE(status))
			goto out;
	}

	root = acpi_pci_find_root(phandle);
	if (!root)
		goto out;

	pbus = root->bus;

	/*
	 * Now, walk back down the PCI device tree until we return to our
	 * original handle. Assumes that everything between the PCI root
	 * bridge and the device we're looking for must be a P2P bridge.
	 */
	list_for_each_entry(node, &device_list, node) {
		acpi_handle hnd = node->handle;
		status = acpi_evaluate_integer(hnd, "_ADR", NULL, &adr);
		if (ACPI_FAILURE(status))
			goto out;
		dev = (adr >> 16) & 0xffff;
		fn  = adr & 0xffff;

		pdev = pci_get_slot(pbus, PCI_DEVFN(dev, fn));
		if (hnd == handle)
			break;

		pbus = pdev->subordinate;
		pci_dev_put(pdev);
	}
out:
	list_for_each_entry_safe(node, tmp, &device_list, node)
		kfree(node);

	return pdev;
}
EXPORT_SYMBOL_GPL(acpi_get_pci_dev);

/**
/**
 * acpi_pci_osc_control_set - commit requested control to Firmware
 * acpi_pci_osc_control_set - commit requested control to Firmware
 * @handle: acpi_handle for the target ACPI object
 * @handle: acpi_handle for the target ACPI object
+1 −0
Original line number Original line Diff line number Diff line
@@ -98,6 +98,7 @@ void acpi_pci_irq_del_prt(int segment, int bus);


struct pci_bus;
struct pci_bus;


struct pci_dev *acpi_get_pci_dev(acpi_handle);
acpi_status acpi_get_pci_id(acpi_handle handle, struct acpi_pci_id *id);
acpi_status acpi_get_pci_id(acpi_handle handle, struct acpi_pci_id *id);
int acpi_pci_bind_root(struct acpi_device *device, struct acpi_pci_id *id,
int acpi_pci_bind_root(struct acpi_device *device, struct acpi_pci_id *id,
		       struct pci_bus *bus);
		       struct pci_bus *bus);