1 files changed, 58 insertions, 43 deletions

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 72a2c98bc429..bce469c0b48a 100644
--- a/drivers/acpi/pci_root.c
+++ b/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;
 }