platform/x86: wmi: Remove wmi_block_list

The wmi_block_list is only used by guid_count() and without proper
protection. It also duplicates some of the WMI bus functionality.

Remove the wmi_block_list and use bus_for_each_dev() instead.

Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20241026193803.8802-1-W_Armin@gmx.de
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 2d6885c67ac0f6f441012a46a6b50ba79aa6a919..4704e79197f6a6c1f4c72ef0905d141ad4b90a56 100644 (file)
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -22,7 +22,6 @@
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
-#include <linux/list.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/rwsem.h>
@@ -37,8 +36,6 @@ MODULE_AUTHOR("Carlos Corbacho");
 MODULE_DESCRIPTION("ACPI-WMI Mapping Driver");
 MODULE_LICENSE("GPL");
 
-static LIST_HEAD(wmi_block_list);
-
 struct guid_block {
        guid_t guid;
        union {
@@ -63,7 +60,6 @@ enum {        /* wmi_block flags */
 
 struct wmi_block {
        struct wmi_device dev;
-       struct list_head list;
        struct guid_block gblock;
        struct acpi_device *acpi_device;
        struct rw_semaphore notify_lock;        /* Protects notify callback add/remove */
@@ -73,6 +69,10 @@ struct wmi_block {
        unsigned long flags;
 };
 
+struct wmi_guid_count_context {
+       const guid_t *guid;
+       int count;
+};
 
 /*
  * If the GUID data block is marked as expensive, we must enable and
@@ -942,21 +942,30 @@ static const struct device_type wmi_type_data = {
        .release = wmi_dev_release,
 };
 
-/*
- * _WDG is a static list that is only parsed at startup,
- * so it's safe to count entries without extra protection.
- */
+static int wmi_count_guids(struct device *dev, void *data)
+{
+       struct wmi_guid_count_context *context = data;
+       struct wmi_block *wblock = dev_to_wblock(dev);
+
+       if (guid_equal(&wblock->gblock.guid, context->guid))
+               context->count++;
+
+       return 0;
+}
+
 static int guid_count(const guid_t *guid)
 {
-       struct wmi_block *wblock;
-       int count = 0;
+       struct wmi_guid_count_context context = {
+               .guid = guid,
+               .count = 0,
+       };
+       int ret;
 
-       list_for_each_entry(wblock, &wmi_block_list, list) {
-               if (guid_equal(&wblock->gblock.guid, guid))
-                       count++;
-       }
+       ret = bus_for_each_dev(&wmi_bus_type, NULL, &context, wmi_count_guids);
+       if (ret < 0)
+               return ret;
 
-       return count;
+       return context.count;
 }
 
 static int wmi_create_device(struct device *wmi_bus_dev,
@@ -967,7 +976,7 @@ static int wmi_create_device(struct device *wmi_bus_dev,
        struct acpi_device_info *info;
        acpi_handle method_handle;
        acpi_status status;
-       uint count;
+       int count;
 
        if (wblock->gblock.flags & ACPI_WMI_EVENT) {
                wblock->dev.dev.type = &wmi_type_event;
@@ -1035,6 +1044,9 @@ static int wmi_create_device(struct device *wmi_bus_dev,
        wblock->dev.dev.parent = wmi_bus_dev;
 
        count = guid_count(&wblock->gblock.guid);
+       if (count < 0)
+               return count;
+
        if (count) {
                dev_set_name(&wblock->dev.dev, "%pUL-%d", &wblock->gblock.guid, count);
                set_bit(WMI_GUID_DUPLICATED, &wblock->flags);
@@ -1120,14 +1132,11 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
                        continue;
                }
 
-               list_add_tail(&wblock->list, &wmi_block_list);
-
                retval = wmi_add_device(pdev, &wblock->dev);
                if (retval) {
                        dev_err(wmi_bus_dev, "failed to register %pUL\n",
                                &wblock->gblock.guid);
 
-                       list_del(&wblock->list);
                        put_device(&wblock->dev.dev);
                }
        }
@@ -1227,9 +1236,6 @@ static void acpi_wmi_notify_handler(acpi_handle handle, u32 event, void *context
 
 static int wmi_remove_device(struct device *dev, void *data)
 {
-       struct wmi_block *wblock = dev_to_wblock(dev);
-
-       list_del(&wblock->list);
        device_unregister(dev);
 
        return 0;