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: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/hotplug/pciehp_pci.c b/drivers/pci/hotplug/pciehp_pci.c
index 09cecaf450c5bebb3a56410f9bf3871d120019bb..aac7a40e4a4ac9205441d9c6918a080531117571 100644 (file)
--- a/drivers/pci/hotplug/pciehp_pci.c
+++ b/drivers/pci/hotplug/pciehp_pci.c
@@ -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;