Commit 0aa089cd authored by Ilpo Järvinen's avatar Ilpo Järvinen Committed by Bjorn Helgaas
Browse files

PCI: Refactor pdev_sort_resources() & __dev_sort_resources() 

Reduce level of call nesting by calling pdev_sort_resources() directly
and by moving the tests done inside __dev_sort_resources() into
pdev_resources_assignable() helper.

Link: https://lore.kernel.org/r/20241216175632.4175-14-ilpo.jarvinen@linux.intel.com


Signed-off-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Tested-by: default avatarXiaochun Lee <lixc17@lenovo.com>
parent 22fb2eda

drivers/pci/setup-bus.c

+23 −21
Original line number Diff line number Diff line
@@ -127,12 +127,33 @@ static resource_size_t get_res_add_align(struct list_head *head, 
	return dev_res ? dev_res->min_align : 0;

}



static bool pdev_resources_assignable(struct pci_dev *dev)

{

	u16 class = dev->class >> 8, command;



	/* Don't touch classless devices or host bridges or IOAPICs */

	if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)

		return false;



	/* Don't touch IOAPIC devices already enabled by firmware */

	if (class == PCI_CLASS_SYSTEM_PIC) {

		pci_read_config_word(dev, PCI_COMMAND, &command);

		if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))

			return false;

	}



	return true;

}



/* Sort resources by alignment */

static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head)

{

	struct resource *r;

	int i;



	if (!pdev_resources_assignable(dev))

		return;



	pci_dev_for_each_resource(dev, r, i) {

		const char *r_name = pci_resource_name(dev, i);

		struct pci_dev_resource *dev_res, *tmp;
@@ -176,25 +197,6 @@ static void pdev_sort_resources(struct pci_dev *dev, struct list_head *head) 
	}

}



static void __dev_sort_resources(struct pci_dev *dev, struct list_head *head)

{

	u16 class = dev->class >> 8;



	/* Don't touch classless devices or host bridges or IOAPICs */

	if (class == PCI_CLASS_NOT_DEFINED || class == PCI_CLASS_BRIDGE_HOST)

		return;



	/* Don't touch IOAPIC devices already enabled by firmware */

	if (class == PCI_CLASS_SYSTEM_PIC) {

		u16 command;

		pci_read_config_word(dev, PCI_COMMAND, &command);

		if (command & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY))

			return;

	}



	pdev_sort_resources(dev, head);

}



static inline void reset_resource(struct resource *res)

{

	res->start = 0;
@@ -498,7 +500,7 @@ static void pdev_assign_resources_sorted(struct pci_dev *dev, 
{

	LIST_HEAD(head);



	__dev_sort_resources(dev, &head);

	pdev_sort_resources(dev, &head);

	__assign_resources_sorted(&head, add_head, fail_head);



}
@@ -511,7 +513,7 @@ static void pbus_assign_resources_sorted(const struct pci_bus *bus, 
	LIST_HEAD(head);



	list_for_each_entry(dev, &bus->devices, bus_list)

		__dev_sort_resources(dev, &head);

		pdev_sort_resources(dev, &head);



	__assign_resources_sorted(&head, realloc_head, fail_head);

}