pciehp: fix interrupt initialization

Current pciehp driver's intialization sequence is as follows:

(1) initialize controller data structure
(2) install interrupt handler
(3) enable software notification
(4) initialize controller specific slot data structure
(5) initialize generic slot data structure and register it to pci hotplug core

The interrupt handler of pciehp assumes that controller specific slot
data structure is already initialized. However, it is installed at (2)
before initializing controller specific slot data structure at
(4). Because of this, pciehp driver cannot handle the following cases
properly.

- If devices that shares IRQ with pciehp raise interrupts between (2) and (4).
- If hotplug events (e.g. MRL open) happen between (3) and (4).

We already have a workaround for this problem ("pciehp: fix NULL
dereference in interrupt handler: dbd79aed1aea2bece0bf43cc2ff3b2f9baf48a08).
But we still need fundamental fix.

This patch fix the problem by changing the initilization sequence as follows:

(1) initialize controller data structure
(2) initialize controller specific slot data structure
(3) install interrupt handler
(4) enable software notification
(5) initialize generic slot data structure and register it to pci hotplug core

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Acked-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 12 insertions, 68 deletions

diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 7b21c86e4bff..d0fb56936911 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -41,7 +41,7 @@ int pciehp_debug;
 int pciehp_poll_mode;
 int pciehp_poll_time;
 int pciehp_force;
-static int pciehp_slot_with_bus;
+int pciehp_slot_with_bus;
 struct workqueue_struct *pciehp_wq;
 
 #define DRIVER_VERSION  "0.4"
@@ -183,23 +183,10 @@ static struct hotplug_slot_attribute hotplug_slot_attr_lock = {
  */
 static void release_slot(struct hotplug_slot *hotplug_slot)
 {
-        struct slot *slot = hotplug_slot->private;
-
         dbg("%s - physical_slot = %s\n", __func__, hotplug_slot->name);
 
-        kfree(slot->hotplug_slot->info);
-        kfree(slot->hotplug_slot);
-        kfree(slot);
-}
-
-static void make_slot_name(struct slot *slot)
-{
-        if (pciehp_slot_with_bus)
-                snprintf(slot->hotplug_slot->name, SLOT_NAME_SIZE, "%04d_%04d",
-                         slot->bus, slot->number);
-        else
-                snprintf(slot->hotplug_slot->name, SLOT_NAME_SIZE, "%d",
-                         slot->number);
+        kfree(hotplug_slot->info);
+        kfree(hotplug_slot);
 }
 
 static int init_slots(struct controller *ctrl)
@@ -208,44 +195,27 @@ static int init_slots(struct controller *ctrl)
         struct hotplug_slot *hotplug_slot;
         struct hotplug_slot_info *info;
         int retval = -ENOMEM;
-        int i;
-
-        for (i = 0; i < ctrl->num_slots; i++) {
-                slot = kzalloc(sizeof(*slot), GFP_KERNEL);
-                if (!slot)
-                        goto error;
 
+        list_for_each_entry(slot, &ctrl->slot_list, slot_list) {
                 hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
                 if (!hotplug_slot)
-                        goto error_slot;
-                slot->hotplug_slot = hotplug_slot;
+                        goto error;
 
                 info = kzalloc(sizeof(*info), GFP_KERNEL);
                 if (!info)
                         goto error_hpslot;
-                hotplug_slot->info = info;
-
-                hotplug_slot->name = slot->name;
-
-                slot->hp_slot = i;
-                slot->ctrl = ctrl;
-                slot->bus = ctrl->pci_dev->subordinate->number;
-                slot->device = ctrl->slot_device_offset + i;
-                slot->hpc_ops = ctrl->hpc_ops;
-                slot->number = ctrl->first_slot;
-                mutex_init(&slot->lock);
-                INIT_DELAYED_WORK(&slot->work, pciehp_queue_pushbutton_work);
 
                 /* register this slot with the hotplug pci core */
+                hotplug_slot->info = info;
+                hotplug_slot->name = slot->name;
                 hotplug_slot->private = slot;
                 hotplug_slot->release = &release_slot;
-                make_slot_name(slot);
                 hotplug_slot->ops = &pciehp_hotplug_slot_ops;
-
                 get_power_status(hotplug_slot, &info->power_status);
                 get_attention_status(hotplug_slot, &info->attention_status);
                 get_latch_status(hotplug_slot, &info->latch_status);
                 get_adapter_status(hotplug_slot, &info->adapter_status);
+                slot->hotplug_slot = hotplug_slot;
 
                 dbg("Registering bus=%x dev=%x hp_slot=%x sun=%x "
                     "slot_device_offset=%x\n", slot->bus, slot->device,
@@ -271,8 +241,6 @@ static int init_slots(struct controller *ctrl)
                                 goto error_info;
                         }
                 }
-
-                list_add(&slot->slot_list, &ctrl->slot_list);
         }
 
         return 0;
@@ -280,27 +248,18 @@ error_info:
         kfree(info);
 error_hpslot:
         kfree(hotplug_slot);
-error_slot:
-        kfree(slot);
 error:
         return retval;
 }
 
 static void cleanup_slots(struct controller *ctrl)
 {
-        struct list_head *tmp;
-        struct list_head *next;
         struct slot *slot;
 
-        list_for_each_safe(tmp, next, &ctrl->slot_list) {
-                slot = list_entry(tmp, struct slot, slot_list);
-                list_del(&slot->slot_list);
+        list_for_each_entry(slot, &ctrl->slot_list, slot_list) {
                 if (EMI(ctrl))
                         sysfs_remove_file(&slot->hotplug_slot->pci_slot->kobj,
                                 &hotplug_slot_attr_lock.attr);
-                cancel_delayed_work(&slot->work);
-                flush_scheduled_work();
-                flush_workqueue(pciehp_wq);
                 pci_hp_deregister(slot->hotplug_slot);
         }
 }
@@ -441,25 +400,13 @@ static int pciehp_probe(struct pcie_device *dev, const struct pcie_port_service_
         else if (pciehp_get_hp_hw_control_from_firmware(pdev))
                 goto err_out_none;
 
-        ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+        ctrl = pcie_init(dev);
         if (!ctrl) {
-                err("%s : out of memory\n", __func__);
-                goto err_out_none;
-        }
-        INIT_LIST_HEAD(&ctrl->slot_list);
-
-        rc = pcie_init(ctrl, dev);
-        if (rc) {
                 dbg("%s: controller initialization failed\n", PCIE_MODULE_NAME);
-                goto err_out_free_ctrl;
+                goto err_out_none;
         }
-
         pci_set_drvdata(pdev, ctrl);
 
-        dbg("%s: ctrl bus=0x%x, device=%x, function=%x, irq=%x\n",
-            __func__, pdev->bus->number, PCI_SLOT(pdev->devfn),
-            PCI_FUNC(pdev->devfn), pdev->irq);
-
         /* Setup the slot information structures */
         rc = init_slots(ctrl);
         if (rc) {
@@ -492,8 +439,6 @@ err_out_free_ctrl_slot:
         cleanup_slots(ctrl);
 err_out_release_ctlr:
         ctrl->hpc_ops->release_ctlr(ctrl);
-err_out_free_ctrl:
-        kfree(ctrl);
 err_out_none:
         return -ENODEV;
 }
@@ -505,7 +450,6 @@ static void pciehp_remove (struct pcie_device *dev)
 
         cleanup_slots(ctrl);
         ctrl->hpc_ops->release_ctlr(ctrl);
-        kfree(ctrl);
 }
 
 #ifdef CONFIG_PM
@@ -525,7 +469,7 @@ static int pciehp_resume (struct pcie_device *dev)
                 u8 status;
 
                 /* reinitialize the chipset's event detection logic */
-                pcie_init_hardware_part2(ctrl, dev);
+                pcie_enable_notification(ctrl);
 
                 t_slot = pciehp_find_slot(ctrl, ctrl->slot_device_offset);