Commit ba518e3c authored by Yijing Wang's avatar Yijing Wang Committed by Bjorn Helgaas
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PCI: pciehp: Iterate over all devices in slot, not functions 0-7 



Currently, we enumerate devices in a slot with pci_scan_slot(), then
iterate through all the devices we found by looking for functions 0-7.  But
that's wrong for ARI devices, which may have function numbers up to 255.

This means that when we hot-add an ARI device, pciehp only initializes
functions 0-7, and other functions don't work correctly.  Additionally, if
we hot-remove the device, pciehp only removes functions 0-7, leaving stale
pci_dev structures for any other functions.

This patch fixes the problem by iterating over devices in a slot by using
the upstream bridge's "bus->devices" list instead.

[bhelgaas: changelog]
Signed-off-by: default avatarYijing Wang <wangyijing@huawei.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent b1bd58e4

drivers/pci/hotplug/pciehp_pci.c

+16 −28
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ int pciehp_configure_device(struct slot *p_slot) 
	struct pci_dev *dev;

	struct pci_dev *bridge = p_slot->ctrl->pcie->port;

	struct pci_bus *parent = bridge->subordinate;

	int num, fn;

	int num;

	struct controller *ctrl = p_slot->ctrl;



	dev = pci_get_slot(parent, PCI_DEVFN(0, 0));
@@ -57,28 +57,18 @@ int pciehp_configure_device(struct slot *p_slot) 
		return -ENODEV;

	}



	for (fn = 0; fn < 8; fn++) {

		dev = pci_get_slot(parent, PCI_DEVFN(0, fn));

		if (!dev)

			continue;

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

		if ((dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) ||

				(dev->hdr_type == PCI_HEADER_TYPE_CARDBUS))

			pci_hp_add_bridge(dev);

		pci_dev_put(dev);

	}



	pci_assign_unassigned_bridge_resources(bridge);



	for (fn = 0; fn < 8; fn++) {

		dev = pci_get_slot(parent, PCI_DEVFN(0, fn));

		if (!dev)

	list_for_each_entry(dev, &parent->devices, bus_list) {

		if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY)

			continue;

		if ((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) {

			pci_dev_put(dev);

			continue;

		}



		pci_configure_slot(dev);

		pci_dev_put(dev);

	}



	pci_bus_add_devices(parent);
@@ -89,9 +79,9 @@ int pciehp_configure_device(struct slot *p_slot) 
int pciehp_unconfigure_device(struct slot *p_slot)

{

	int ret, rc = 0;

	int j;

	u8 bctl = 0;

	u8 presence = 0;

	struct pci_dev *dev, *temp;

	struct pci_bus *parent = p_slot->ctrl->pcie->port->subordinate;

	u16 command;

	struct controller *ctrl = p_slot->ctrl;
@@ -102,33 +92,31 @@ int pciehp_unconfigure_device(struct slot *p_slot) 
	if (ret)

		presence = 0;



	for (j = 0; j < 8; j++) {

		struct pci_dev *temp = pci_get_slot(parent, PCI_DEVFN(0, j));

		if (!temp)

			continue;

		if (temp->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {

			pci_read_config_byte(temp, PCI_BRIDGE_CONTROL, &bctl);

	list_for_each_entry_safe(dev, temp, &parent->devices, bus_list) {

		pci_dev_get(dev);

		if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE && presence) {

			pci_read_config_byte(dev, PCI_BRIDGE_CONTROL, &bctl);

			if (bctl & PCI_BRIDGE_CTL_VGA) {

				ctrl_err(ctrl,

					 "Cannot remove display device %s\n",

					 pci_name(temp));

				pci_dev_put(temp);

					 pci_name(dev));

				pci_dev_put(dev);

				rc = -EINVAL;

				break;

			}

		}

		pci_stop_and_remove_bus_device(temp);

		pci_stop_and_remove_bus_device(dev);

		/*

		 * Ensure that no new Requests will be generated from

		 * the device.

		 */

		if (presence) {

			pci_read_config_word(temp, PCI_COMMAND, &command);

			pci_read_config_word(dev, PCI_COMMAND, &command);

			command &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_SERR);

			command |= PCI_COMMAND_INTX_DISABLE;

			pci_write_config_word(temp, PCI_COMMAND, command);

			pci_write_config_word(dev, PCI_COMMAND, command);

		}

		pci_dev_put(temp);

		pci_dev_put(dev);

	}



	return rc;

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