1 files changed, 34 insertions, 47 deletions

diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c
index b285386eb37f..7ec4cd1e7245 100644
--- a/drivers/acpi/acpi_ipmi.c
+++ b/drivers/acpi/acpi_ipmi.c
@@ -46,7 +46,6 @@ MODULE_AUTHOR("Zhao Yakui");
 MODULE_DESCRIPTION("ACPI IPMI Opregion driver");
 MODULE_LICENSE("GPL");
 
-#define IPMI_FLAGS_HANDLER_INSTALL      0
 
 #define ACPI_IPMI_OK                    0
 #define ACPI_IPMI_TIMEOUT               0x10
@@ -66,7 +65,6 @@ struct acpi_ipmi_device {
         ipmi_user_t     user_interface;
         int ipmi_ifnum; /* IPMI interface number */
         long curr_msgid;
-        unsigned long flags;
         struct ipmi_smi_info smi_data;
         bool dead;
         struct kref kref;
@@ -77,6 +75,14 @@ struct ipmi_driver_data {
         struct ipmi_smi_watcher bmc_events;
         struct ipmi_user_hndl   ipmi_hndlrs;
         struct mutex            ipmi_lock;
+        /*
+         * NOTE: IPMI System Interface Selection
+         * There is no system interface specified by the IPMI operation
+         * region access.  We try to select one system interface with ACPI
+         * handle set.  IPMI messages passed from the ACPI codes are sent
+         * to this selected global IPMI system interface.
+         */
+        struct acpi_ipmi_device *selected_smi;
 };
 
 struct acpi_ipmi_msg {
@@ -110,8 +116,6 @@ struct acpi_ipmi_buffer {
 static void ipmi_register_bmc(int iface, struct device *dev);
 static void ipmi_bmc_gone(int iface);
 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
-static int ipmi_install_space_handler(struct acpi_ipmi_device *ipmi);
-static void ipmi_remove_space_handler(struct acpi_ipmi_device *ipmi);
 
 static struct ipmi_driver_data driver_data = {
         .ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices),
@@ -154,14 +158,12 @@ ipmi_dev_alloc(int iface, struct ipmi_smi_info *smi_data, acpi_handle handle)
                 return NULL;
         }
         ipmi_device->user_interface = user;
-        ipmi_install_space_handler(ipmi_device);
 
         return ipmi_device;
 }
 
 static void ipmi_dev_release(struct acpi_ipmi_device *ipmi_device)
 {
-        ipmi_remove_space_handler(ipmi_device);
         ipmi_destroy_user(ipmi_device->user_interface);
         put_device(ipmi_device->smi_data.dev);
         kfree(ipmi_device);
@@ -178,6 +180,8 @@ static void ipmi_dev_release_kref(struct kref *kref)
 static void __ipmi_dev_kill(struct acpi_ipmi_device *ipmi_device)
 {
         list_del(&ipmi_device->head);
+        if (driver_data.selected_smi == ipmi_device)
+                driver_data.selected_smi = NULL;
         /*
          * Always setting dead flag after deleting from the list or
          * list_for_each_entry() codes must get changed.
@@ -185,17 +189,14 @@ static void __ipmi_dev_kill(struct acpi_ipmi_device *ipmi_device)
         ipmi_device->dead = true;
 }
 
-static struct acpi_ipmi_device *acpi_ipmi_dev_get(int iface)
+static struct acpi_ipmi_device *acpi_ipmi_dev_get(void)
 {
-        struct acpi_ipmi_device *temp, *ipmi_device = NULL;
+        struct acpi_ipmi_device *ipmi_device = NULL;
 
         mutex_lock(&driver_data.ipmi_lock);
-        list_for_each_entry(temp, &driver_data.ipmi_devices, head) {
-                if (temp->ipmi_ifnum == iface) {
-                        ipmi_device = temp;
-                        kref_get(&ipmi_device->kref);
-                        break;
-                }
+        if (driver_data.selected_smi) {
+                ipmi_device = driver_data.selected_smi;
+                kref_get(&ipmi_device->kref);
         }
         mutex_unlock(&driver_data.ipmi_lock);
 
@@ -416,6 +417,8 @@ static void ipmi_register_bmc(int iface, struct device *dev)
                         goto err_lock;
         }
 
+        if (!driver_data.selected_smi)
+                driver_data.selected_smi = ipmi_device;
         list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);
         mutex_unlock(&driver_data.ipmi_lock);
         put_device(smi_data.dev);
@@ -443,6 +446,10 @@ static void ipmi_bmc_gone(int iface)
                         break;
                 }
         }
+        if (!driver_data.selected_smi)
+                driver_data.selected_smi = list_first_entry_or_null(
+                                        &driver_data.ipmi_devices,
+                                        struct acpi_ipmi_device, head);
         mutex_unlock(&driver_data.ipmi_lock);
         if (dev_found) {
                 ipmi_flush_tx_msg(ipmi_device);
@@ -471,7 +478,6 @@ acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
                       void *handler_context, void *region_context)
 {
         struct acpi_ipmi_msg *tx_msg;
-        int iface = (long)handler_context;
         struct acpi_ipmi_device *ipmi_device;
         int err;
         acpi_status status;
@@ -485,7 +491,7 @@ acpi_ipmi_space_handler(u32 function, acpi_physical_address address,
         if ((function & ACPI_IO_MASK) == ACPI_READ)
                 return AE_TYPE;
 
-        ipmi_device = acpi_ipmi_dev_get(iface);
+        ipmi_device = acpi_ipmi_dev_get();
         if (!ipmi_device)
                 return AE_NOT_EXIST;
 
@@ -534,47 +540,26 @@ out_ref:
         return status;
 }
 
-static void ipmi_remove_space_handler(struct acpi_ipmi_device *ipmi)
-{
-        if (!test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
-                return;
-
-        acpi_remove_address_space_handler(ipmi->handle,
-                                ACPI_ADR_SPACE_IPMI, &acpi_ipmi_space_handler);
-
-        clear_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
-}
-
-static int ipmi_install_space_handler(struct acpi_ipmi_device *ipmi)
-{
-        acpi_status status;
-
-        if (test_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags))
-                return 0;
-
-        status = acpi_install_address_space_handler(ipmi->handle,
-                                ACPI_ADR_SPACE_IPMI, &acpi_ipmi_space_handler,
-                                NULL, (void *)((long)ipmi->ipmi_ifnum));
-        if (ACPI_FAILURE(status)) {
-                struct pnp_dev *pnp_dev = ipmi->pnp_dev;
-                dev_warn(&pnp_dev->dev, "Can't register IPMI opregion space "
-                        "handle\n");
-                return -EINVAL;
-        }
-        set_bit(IPMI_FLAGS_HANDLER_INSTALL, &ipmi->flags);
-        return 0;
-}
-
 static int __init acpi_ipmi_init(void)
 {
         int result = 0;
+        acpi_status status;
 
         if (acpi_disabled)
                 return result;
 
         mutex_init(&driver_data.ipmi_lock);
 
+        status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,
+                                ACPI_ADR_SPACE_IPMI, &acpi_ipmi_space_handler,
+                                NULL, NULL);
+        if (ACPI_FAILURE(status)) {
+                pr_warn("Can't register IPMI opregion space handle\n");
+                return -EINVAL;
+        }
         result = ipmi_smi_watcher_register(&driver_data.bmc_events);
+        if (result)
+                pr_err("Can't register IPMI system interface watcher\n");
 
         return result;
 }
@@ -608,6 +593,8 @@ static void __exit acpi_ipmi_exit(void)
                 mutex_lock(&driver_data.ipmi_lock);
         }
         mutex_unlock(&driver_data.ipmi_lock);
+        acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
+                                ACPI_ADR_SPACE_IPMI, &acpi_ipmi_space_handler);
 }
 
 module_init(acpi_ipmi_init);