PCI changes for the 3.7 merge window:

Host bridge hotplug
     - Protect acpi_pci_drivers and acpi_pci_roots (Taku Izumi)
     - Clear host bridge resource info to avoid issue when releasing (Yinghai Lu)
     - Notify acpi_pci_drivers when hot-plugging host bridges (Jiang Liu)
     - Use standard list ops for acpi_pci_drivers (Jiang Liu)
 
   Device hotplug
     - Use pci_get_domain_bus_and_slot() to close hotplug races (Jiang Liu)
     - Remove fakephp driver (Bjorn Helgaas)
     - Fix VGA ref count in hotplug remove path (Yinghai Lu)
     - Allow acpiphp to handle PCIe ports without native hotplug (Jiang Liu)
     - Implement resume regardless of pciehp_force param (Oliver Neukum)
     - Make pci_fixup_irqs() work after init (Thierry Reding)
 
   Miscellaneous
     - Add pci_pcie_type(dev) and remove pci_dev.pcie_type (Yijing Wang)
     - Factor out PCI Express Capability accessors (Jiang Liu)
     - Add pcibios_window_alignment() so powerpc EEH can use generic resource assignment (Gavin Shan)
     - Make pci_error_handlers const (Stephen Hemminger)
     - Cleanup drivers/pci/remove.c (Bjorn Helgaas)
     - Improve Vendor-Specific Extended Capability support (Bjorn Helgaas)
     - Use standard list ops for bus->devices (Bjorn Helgaas)
     - Avoid kmalloc in pci_get_subsys() and pci_get_class() (Feng Tang)
     - Reassign invalid bus number ranges (Intel DP43BF workaround) (Yinghai Lu)
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Merge tag 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI changes from Bjorn Helgaas:
 "Host bridge hotplug
    - Protect acpi_pci_drivers and acpi_pci_roots (Taku Izumi)
    - Clear host bridge resource info to avoid issue when releasing
      (Yinghai Lu)
    - Notify acpi_pci_drivers when hot-plugging host bridges (Jiang Liu)
    - Use standard list ops for acpi_pci_drivers (Jiang Liu)

  Device hotplug
    - Use pci_get_domain_bus_and_slot() to close hotplug races (Jiang
      Liu)
    - Remove fakephp driver (Bjorn Helgaas)
    - Fix VGA ref count in hotplug remove path (Yinghai Lu)
    - Allow acpiphp to handle PCIe ports without native hotplug (Jiang
      Liu)
    - Implement resume regardless of pciehp_force param (Oliver Neukum)
    - Make pci_fixup_irqs() work after init (Thierry Reding)

  Miscellaneous
    - Add pci_pcie_type(dev) and remove pci_dev.pcie_type (Yijing Wang)
    - Factor out PCI Express Capability accessors (Jiang Liu)
    - Add pcibios_window_alignment() so powerpc EEH can use generic
      resource assignment (Gavin Shan)
    - Make pci_error_handlers const (Stephen Hemminger)
    - Cleanup drivers/pci/remove.c (Bjorn Helgaas)
    - Improve Vendor-Specific Extended Capability support (Bjorn
      Helgaas)
    - Use standard list ops for bus->devices (Bjorn Helgaas)
    - Avoid kmalloc in pci_get_subsys() and pci_get_class() (Feng Tang)
    - Reassign invalid bus number ranges (Intel DP43BF workaround)
      (Yinghai Lu)"

* tag 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (102 commits)
  PCI: acpiphp: Handle PCIe ports without native hotplug capability
  PCI/ACPI: Use acpi_driver_data() rather than searching acpi_pci_roots
  PCI/ACPI: Protect acpi_pci_roots list with mutex
  PCI/ACPI: Use acpi_pci_root info rather than looking it up again
  PCI/ACPI: Pass acpi_pci_root to acpi_pci_drivers' add/remove interface
  PCI/ACPI: Protect acpi_pci_drivers list with mutex
  PCI/ACPI: Notify acpi_pci_drivers when hot-plugging PCI root bridges
  PCI/ACPI: Use normal list for struct acpi_pci_driver
  PCI/ACPI: Use DEVICE_ACPI_HANDLE rather than searching acpi_pci_roots
  PCI: Fix default vga ref_count
  ia64/PCI: Clear host bridge aperture struct resource
  x86/PCI: Clear host bridge aperture struct resource
  PCI: Stop all children first, before removing all children
  Revert "PCI: Use hotplug-safe pci_get_domain_bus_and_slot()"
  PCI: Provide a default pcibios_update_irq()
  PCI: Discard __init annotations for pci_fixup_irqs() and related functions
  PCI: Use correct type when freeing bus resource list
  PCI: Check P2P bridge for invalid secondary/subordinate range
  PCI: Convert "new_id"/"remove_id" into generic pci_bus driver attributes
  xen-pcifront: Use hotplug-safe pci_get_domain_bus_and_slot()
  ...

drivers/acpi/pci_root.c

@@ -27,7 +27,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/types.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/pci.h>
@@ -71,9 +71,11 @@ static struct acpi_driver acpi_pci_root_driver = {
 		},
 };
 
+/* Lock to protect both acpi_pci_roots and acpi_pci_drivers lists */
+static DEFINE_MUTEX(acpi_pci_root_lock);
 static LIST_HEAD(acpi_pci_roots);
+static LIST_HEAD(acpi_pci_drivers);
 
-static struct acpi_pci_driver *sub_driver;
 static DEFINE_MUTEX(osc_lock);
 
 int acpi_pci_register_driver(struct acpi_pci_driver *driver)
@@ -81,55 +83,46 @@ int acpi_pci_register_driver(struct acpi_pci_driver *driver)
 	int n = 0;
 	struct acpi_pci_root *root;
 
-	struct acpi_pci_driver **pptr = &sub_driver;
-	while (*pptr)
-		pptr = &(*pptr)->next;
-	*pptr = driver;
-
-	if (!driver->add)
-		return 0;
-
-	list_for_each_entry(root, &acpi_pci_roots, node) {
-		driver->add(root->device->handle);
-		n++;
-	}
+	mutex_lock(&acpi_pci_root_lock);
+	list_add_tail(&driver->node, &acpi_pci_drivers);
+	if (driver->add)
+		list_for_each_entry(root, &acpi_pci_roots, node) {
+			driver->add(root);
+			n++;
+		}
+	mutex_unlock(&acpi_pci_root_lock);
 
 	return n;
 }
-
 EXPORT_SYMBOL(acpi_pci_register_driver);
 
 void acpi_pci_unregister_driver(struct acpi_pci_driver *driver)
 {
 	struct acpi_pci_root *root;
 
-	struct acpi_pci_driver **pptr = &sub_driver;
-	while (*pptr) {
-		if (*pptr == driver)
-			break;
-		pptr = &(*pptr)->next;
-	}
-	BUG_ON(!*pptr);
-	*pptr = (*pptr)->next;
-
-	if (!driver->remove)
-		return;
-
-	list_for_each_entry(root, &acpi_pci_roots, node)
-		driver->remove(root->device->handle);
+	mutex_lock(&acpi_pci_root_lock);
+	list_del(&driver->node);
+	if (driver->remove)
+		list_for_each_entry(root, &acpi_pci_roots, node)
+			driver->remove(root);
+	mutex_unlock(&acpi_pci_root_lock);
 }
-
 EXPORT_SYMBOL(acpi_pci_unregister_driver);
 
 acpi_handle acpi_get_pci_rootbridge_handle(unsigned int seg, unsigned int bus)
 {
 	struct acpi_pci_root *root;
+	acpi_handle handle = NULL;
 	
+	mutex_lock(&acpi_pci_root_lock);
 	list_for_each_entry(root, &acpi_pci_roots, node)
 		if ((root->segment == (u16) seg) &&
-		    (root->secondary.start == (u16) bus))
-			return root->device->handle;
-	return NULL;		
+		    (root->secondary.start == (u16) bus)) {
+			handle = root->device->handle;
+			break;
+		}
+	mutex_unlock(&acpi_pci_root_lock);
+	return handle;
 }
 
 EXPORT_SYMBOL_GPL(acpi_get_pci_rootbridge_handle);
@@ -277,12 +270,15 @@ static acpi_status acpi_pci_osc_support(struct acpi_pci_root *root, u32 flags)
 struct acpi_pci_root *acpi_pci_find_root(acpi_handle handle)
 {
 	struct acpi_pci_root *root;
+	struct acpi_device *device;
 
-	list_for_each_entry(root, &acpi_pci_roots, node) {
-		if (root->device->handle == handle)
-			return root;
-	}
-	return NULL;
+	if (acpi_bus_get_device(handle, &device) ||
+	    acpi_match_device_ids(device, root_device_ids))
+		return NULL;
+
+	root = acpi_driver_data(device);
+
+	return root;
 }
 EXPORT_SYMBOL_GPL(acpi_pci_find_root);
 
@@ -518,8 +514,9 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	 * TBD: Need PCI interface for enumeration/configuration of roots.
 	 */
 
-	/* TBD: Locking */
+	mutex_lock(&acpi_pci_root_lock);
 	list_add_tail(&root->node, &acpi_pci_roots);
+	mutex_unlock(&acpi_pci_root_lock);
 
 	printk(KERN_INFO PREFIX "%s [%s] (domain %04x %pR)\n",
 	       acpi_device_name(device), acpi_device_bid(device),
@@ -538,7 +535,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 			    "Bus %04x:%02x not present in PCI namespace\n",
 			    root->segment, (unsigned int)root->secondary.start);
 		result = -ENODEV;
-		goto end;
+		goto out_del_root;
 	}
 
 	/*
@@ -548,7 +545,7 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 	 */
 	result = acpi_pci_bind_root(device);
 	if (result)
-		goto end;
+		goto out_del_root;
 
 	/*
 	 * PCI Routing Table
@@ -633,9 +630,11 @@ static int __devinit acpi_pci_root_add(struct acpi_device *device)
 
 	return 0;
 
+out_del_root:
+	mutex_lock(&acpi_pci_root_lock);
+	list_del(&root->node);
+	mutex_unlock(&acpi_pci_root_lock);
 end:
-	if (!list_empty(&root->node))
-		list_del(&root->node);
 	kfree(root);
 	return result;
 }
@@ -643,18 +642,34 @@ end:
 static int acpi_pci_root_start(struct acpi_device *device)
 {
 	struct acpi_pci_root *root = acpi_driver_data(device);
+	struct acpi_pci_driver *driver;
+
+	mutex_lock(&acpi_pci_root_lock);
+	list_for_each_entry(driver, &acpi_pci_drivers, node)
+		if (driver->add)
+			driver->add(root);
+	mutex_unlock(&acpi_pci_root_lock);
 
 	pci_bus_add_devices(root->bus);
+
 	return 0;
 }
 
 static int acpi_pci_root_remove(struct acpi_device *device, int type)
 {
 	struct acpi_pci_root *root = acpi_driver_data(device);
+	struct acpi_pci_driver *driver;
+
+	mutex_lock(&acpi_pci_root_lock);
+	list_for_each_entry(driver, &acpi_pci_drivers, node)
+		if (driver->remove)
+			driver->remove(root);
 
 	device_set_run_wake(root->bus->bridge, false);
 	pci_acpi_remove_bus_pm_notifier(device);
 
+	list_del(&root->node);
+	mutex_unlock(&acpi_pci_root_lock);
 	kfree(root);
 	return 0;
 }

drivers/acpi/pci_slot.c

@@ -67,8 +67,8 @@ struct acpi_pci_slot {
 	struct list_head list;		/* node in the list of slots */
 };
 
-static int acpi_pci_slot_add(acpi_handle handle);
-static void acpi_pci_slot_remove(acpi_handle handle);
+static int acpi_pci_slot_add(struct acpi_pci_root *root);
+static void acpi_pci_slot_remove(struct acpi_pci_root *root);
 
 static LIST_HEAD(slot_list);
 static DEFINE_MUTEX(slot_list_lock);
@@ -233,45 +233,20 @@ out:
 
 /*
  * walk_root_bridge - generic root bridge walker
- * @handle: points to an acpi_pci_root
+ * @root: poiner of an acpi_pci_root
  * @user_function: user callback for slot objects
  *
  * Call user_function for all objects underneath this root bridge.
  * Walk p2p bridges underneath us and call user_function on those too.
  */
 static int
-walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
+walk_root_bridge(struct acpi_pci_root *root, acpi_walk_callback user_function)
 {
-	int seg, bus;
-	unsigned long long tmp;
 	acpi_status status;
-	acpi_handle dummy_handle;
-	struct pci_bus *pci_bus;
+	acpi_handle handle = root->device->handle;
+	struct pci_bus *pci_bus = root->bus;
 	struct callback_args context;
 
-	/* If the bridge doesn't have _STA, we assume it is always there */
-	status = acpi_get_handle(handle, "_STA", &dummy_handle);
-	if (ACPI_SUCCESS(status)) {
-		status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
-		if (ACPI_FAILURE(status)) {
-			info("%s: _STA evaluation failure\n", __func__);
-			return 0;
-		}
-		if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0)
-			/* don't register this object */
-			return 0;
-	}
-
-	status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
-	seg = ACPI_SUCCESS(status) ? tmp : 0;
-
-	status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
-	bus = ACPI_SUCCESS(status) ? tmp : 0;
-
-	pci_bus = pci_find_bus(seg, bus);
-	if (!pci_bus)
-		return 0;
-
 	context.pci_bus = pci_bus;
 	context.user_function = user_function;
 	context.root_handle = handle;
@@ -295,11 +270,11 @@ walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
  * @handle: points to an acpi_pci_root
  */
 static int
-acpi_pci_slot_add(acpi_handle handle)
+acpi_pci_slot_add(struct acpi_pci_root *root)
 {
 	acpi_status status;
 
-	status = walk_root_bridge(handle, register_slot);
+	status = walk_root_bridge(root, register_slot);
 	if (ACPI_FAILURE(status))
 		err("%s: register_slot failure - %d\n", __func__, status);
 
@@ -311,10 +286,11 @@ acpi_pci_slot_add(acpi_handle handle)
  * @handle: points to an acpi_pci_root
  */
 static void
-acpi_pci_slot_remove(acpi_handle handle)
+acpi_pci_slot_remove(struct acpi_pci_root *root)
 {
 	struct acpi_pci_slot *slot, *tmp;
 	struct pci_bus *pbus;
+	acpi_handle handle = root->device->handle;
 
 	mutex_lock(&slot_list_lock);
 	list_for_each_entry_safe(slot, tmp, &slot_list, list) {