Merge tag 'platform-drivers-x86-v4.16-6' of git://git.infradead.org/linux-platform-drivers-x86

Pull x86 platform driver fixes from Darren Hart:
 "Correct a module loading race condition between the DELL_SMBIOS
  backend modules and the first user by converting them to bool features
  of the DELL_SMBIOS driver. Fixup the resulting Kconfig dependency
  issue with DCDBAS"

* tag 'platform-drivers-x86-v4.16-6' of git://git.infradead.org/linux-platform-drivers-x86:
  platform/x86: dell-smbios: Resolve dependency error on DCDBAS
  platform/x86: Allow for SMBIOS backend defaults
  platform/x86: dell-smbios: Link all dell-smbios-* modules together
  platform/x86: dell-smbios: Rename dell-smbios source to dell-smbios-base
  platform/x86: dell-smbios: Correct some style warnings

6 files changed, 82 insertions, 38 deletions

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 9a8f96465cdc..d10ffe51da24 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -105,31 +105,44 @@ config ASUS_LAPTOP
 
           If you have an ACPI-compatible ASUS laptop, say Y or M here.
 
+#
+# If the DELL_SMBIOS_SMM feature is enabled, the DELL_SMBIOS driver
+# becomes dependent on the DCDBAS driver. The "depends" line prevents a
+# configuration where DELL_SMBIOS=y while DCDBAS=m.
+#
 config DELL_SMBIOS
-        tristate
+        tristate "Dell SMBIOS driver"
+        depends on DCDBAS || DCDBAS=n
+        ---help---
+        This provides support for the Dell SMBIOS calling interface.
+        If you have a Dell computer you should enable this option.
+
+        Be sure to select at least one backend for it to work properly.
 
 config DELL_SMBIOS_WMI
-        tristate "Dell SMBIOS calling interface (WMI implementation)"
+        bool "Dell SMBIOS driver WMI backend"
+        default y
         depends on ACPI_WMI
         select DELL_WMI_DESCRIPTOR
-        select DELL_SMBIOS
+        depends on DELL_SMBIOS
         ---help---
         This provides an implementation for the Dell SMBIOS calling interface
         communicated over ACPI-WMI.
 
-        If you have a Dell computer from >2007 you should say Y or M here.
+        If you have a Dell computer from >2007 you should say Y here.
         If you aren't sure and this module doesn't work for your computer
         it just won't load.
 
 config DELL_SMBIOS_SMM
-        tristate "Dell SMBIOS calling interface (SMM implementation)"
+        bool "Dell SMBIOS driver SMM backend"
+        default y
         depends on DCDBAS
-        select DELL_SMBIOS
+        depends on DELL_SMBIOS
         ---help---
         This provides an implementation for the Dell SMBIOS calling interface
         communicated over SMI/SMM.
 
-        If you have a Dell computer from <=2017 you should say Y or M here.
+        If you have a Dell computer from <=2017 you should say Y here.
         If you aren't sure and this module doesn't work for your computer
         it just won't load.
 
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index c388608ad2a3..2ba6cb795338 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -13,8 +13,9 @@ obj-$(CONFIG_MSI_LAPTOP)	+= msi-laptop.o
 obj-$(CONFIG_ACPI_CMPC)         += classmate-laptop.o
 obj-$(CONFIG_COMPAL_LAPTOP)     += compal-laptop.o
 obj-$(CONFIG_DELL_SMBIOS)       += dell-smbios.o
-obj-$(CONFIG_DELL_SMBIOS_WMI)   += dell-smbios-wmi.o
-obj-$(CONFIG_DELL_SMBIOS_SMM)   += dell-smbios-smm.o
+dell-smbios-objs                := dell-smbios-base.o
+dell-smbios-$(CONFIG_DELL_SMBIOS_WMI)   += dell-smbios-wmi.o
+dell-smbios-$(CONFIG_DELL_SMBIOS_SMM)   += dell-smbios-smm.o
 obj-$(CONFIG_DELL_LAPTOP)       += dell-laptop.o
 obj-$(CONFIG_DELL_WMI)          += dell-wmi.o
 obj-$(CONFIG_DELL_WMI_DESCRIPTOR)       += dell-wmi-descriptor.o
diff --git a/drivers/platform/x86/dell-smbios.c b/drivers/platform/x86/dell-smbios-base.c
index 8541cde4cb7d..5bcf8a18f785 100644
--- a/drivers/platform/x86/dell-smbios.c
+++ b/drivers/platform/x86/dell-smbios-base.c
@@ -36,7 +36,7 @@ static DEFINE_MUTEX(smbios_mutex);
 struct smbios_device {
         struct list_head list;
         struct device *device;
-        int (*call_fn)(struct calling_interface_buffer *);
+        int (*call_fn)(struct calling_interface_buffer *arg);
 };
 
 struct smbios_call {
@@ -352,8 +352,10 @@ static void __init parse_da_table(const struct dmi_header *dm)
         struct calling_interface_structure *table =
                 container_of(dm, struct calling_interface_structure, header);
 
-        /* 4 bytes of table header, plus 7 bytes of Dell header, plus at least
-           6 bytes of entry */
+        /*
+         * 4 bytes of table header, plus 7 bytes of Dell header
+         * plus at least 6 bytes of entry
+         */
 
         if (dm->length < 17)
                 return;
@@ -554,7 +556,7 @@ static void free_group(struct platform_device *pdev)
 static int __init dell_smbios_init(void)
 {
         const struct dmi_device *valid;
-        int ret;
+        int ret, wmi, smm;
 
         valid = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, "Dell System", NULL);
         if (!valid) {
@@ -589,8 +591,24 @@ static int __init dell_smbios_init(void)
         if (ret)
                 goto fail_create_group;
 
+        /* register backends */
+        wmi = init_dell_smbios_wmi();
+        if (wmi)
+                pr_debug("Failed to initialize WMI backend: %d\n", wmi);
+        smm = init_dell_smbios_smm();
+        if (smm)
+                pr_debug("Failed to initialize SMM backend: %d\n", smm);
+        if (wmi && smm) {
+                pr_err("No SMBIOS backends available (wmi: %d, smm: %d)\n",
+                        wmi, smm);
+                goto fail_sysfs;
+        }
+
         return 0;
 
+fail_sysfs:
+        free_group(platform_device);
+
 fail_create_group:
         platform_device_del(platform_device);
 
@@ -607,6 +625,8 @@ fail_platform_driver:
 
 static void __exit dell_smbios_exit(void)
 {
+        exit_dell_smbios_wmi();
+        exit_dell_smbios_smm();
         mutex_lock(&smbios_mutex);
         if (platform_device) {
                 free_group(platform_device);
@@ -623,5 +643,6 @@ module_exit(dell_smbios_exit);
 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
 MODULE_AUTHOR("Gabriele Mazzotta <gabriele.mzt@gmail.com>");
 MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
+MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
 MODULE_DESCRIPTION("Common functions for kernel modules using Dell SMBIOS");
 MODULE_LICENSE("GPL");
diff --git a/drivers/platform/x86/dell-smbios-smm.c b/drivers/platform/x86/dell-smbios-smm.c
index 89f65c4651a0..e9e9da556318 100644
--- a/drivers/platform/x86/dell-smbios-smm.c
+++ b/drivers/platform/x86/dell-smbios-smm.c
@@ -58,7 +58,7 @@ static const struct dmi_system_id dell_device_table[] __initconst = {
 };
 MODULE_DEVICE_TABLE(dmi, dell_device_table);
 
-static void __init parse_da_table(const struct dmi_header *dm)
+static void parse_da_table(const struct dmi_header *dm)
 {
         struct calling_interface_structure *table =
                 container_of(dm, struct calling_interface_structure, header);
@@ -73,7 +73,7 @@ static void __init parse_da_table(const struct dmi_header *dm)
         da_command_code = table->cmdIOCode;
 }
 
-static void __init find_cmd_address(const struct dmi_header *dm, void *dummy)
+static void find_cmd_address(const struct dmi_header *dm, void *dummy)
 {
         switch (dm->type) {
         case 0xda: /* Calling interface */
@@ -128,7 +128,7 @@ static bool test_wsmt_enabled(void)
         return false;
 }
 
-static int __init dell_smbios_smm_init(void)
+int init_dell_smbios_smm(void)
 {
         int ret;
         /*
@@ -176,7 +176,7 @@ fail_platform_device_alloc:
         return ret;
 }
 
-static void __exit dell_smbios_smm_exit(void)
+void exit_dell_smbios_smm(void)
 {
         if (platform_device) {
                 dell_smbios_unregister_device(&platform_device->dev);
@@ -184,13 +184,3 @@ static void __exit dell_smbios_smm_exit(void)
                 free_page((unsigned long)buffer);
         }
 }
-
-subsys_initcall(dell_smbios_smm_init);
-module_exit(dell_smbios_smm_exit);
-
-MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
-MODULE_AUTHOR("Gabriele Mazzotta <gabriele.mzt@gmail.com>");
-MODULE_AUTHOR("Pali Rohár <pali.rohar@gmail.com>");
-MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
-MODULE_DESCRIPTION("Dell SMBIOS communications over SMI");
-MODULE_LICENSE("GPL");
diff --git a/drivers/platform/x86/dell-smbios-wmi.c b/drivers/platform/x86/dell-smbios-wmi.c
index 609557aa5868..fbefedb1c172 100644
--- a/drivers/platform/x86/dell-smbios-wmi.c
+++ b/drivers/platform/x86/dell-smbios-wmi.c
@@ -228,7 +228,7 @@ static const struct wmi_device_id dell_smbios_wmi_id_table[] = {
         { },
 };
 
-static void __init parse_b1_table(const struct dmi_header *dm)
+static void parse_b1_table(const struct dmi_header *dm)
 {
         struct misc_bios_flags_structure *flags =
         container_of(dm, struct misc_bios_flags_structure, header);
@@ -242,7 +242,7 @@ static void __init parse_b1_table(const struct dmi_header *dm)
                 wmi_supported = 1;
 }
 
-static void __init find_b1(const struct dmi_header *dm, void *dummy)
+static void find_b1(const struct dmi_header *dm, void *dummy)
 {
         switch (dm->type) {
         case 0xb1: /* misc bios flags */
@@ -261,7 +261,7 @@ static struct wmi_driver dell_smbios_wmi_driver = {
         .filter_callback = dell_smbios_wmi_filter,
 };
 
-static int __init init_dell_smbios_wmi(void)
+int init_dell_smbios_wmi(void)
 {
         dmi_walk(find_b1, NULL);
 
@@ -271,15 +271,9 @@ static int __init init_dell_smbios_wmi(void)
         return wmi_driver_register(&dell_smbios_wmi_driver);
 }
 
-static void __exit exit_dell_smbios_wmi(void)
+void exit_dell_smbios_wmi(void)
 {
         wmi_driver_unregister(&dell_smbios_wmi_driver);
 }
 
-module_init(init_dell_smbios_wmi);
-module_exit(exit_dell_smbios_wmi);
-
 MODULE_ALIAS("wmi:" DELL_WMI_SMBIOS_GUID);
-MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
-MODULE_DESCRIPTION("Dell SMBIOS communications over WMI");
-MODULE_LICENSE("GPL");
diff --git a/drivers/platform/x86/dell-smbios.h b/drivers/platform/x86/dell-smbios.h
index 138d478d9adc..d8adaf959740 100644
--- a/drivers/platform/x86/dell-smbios.h
+++ b/drivers/platform/x86/dell-smbios.h
@@ -75,4 +75,29 @@ int dell_laptop_register_notifier(struct notifier_block *nb);
 int dell_laptop_unregister_notifier(struct notifier_block *nb);
 void dell_laptop_call_notifier(unsigned long action, void *data);
 
-#endif
+/* for the supported backends */
+#ifdef CONFIG_DELL_SMBIOS_WMI
+int init_dell_smbios_wmi(void);
+void exit_dell_smbios_wmi(void);
+#else /* CONFIG_DELL_SMBIOS_WMI */
+static inline int init_dell_smbios_wmi(void)
+{
+        return -ENODEV;
+}
+static inline void exit_dell_smbios_wmi(void)
+{}
+#endif /* CONFIG_DELL_SMBIOS_WMI */
+
+#ifdef CONFIG_DELL_SMBIOS_SMM
+int init_dell_smbios_smm(void);
+void exit_dell_smbios_smm(void);
+#else /* CONFIG_DELL_SMBIOS_SMM */
+static inline int init_dell_smbios_smm(void)
+{
+        return -ENODEV;
+}
+static inline void exit_dell_smbios_smm(void)
+{}
+#endif /* CONFIG_DELL_SMBIOS_SMM */
+
+#endif /* _DELL_SMBIOS_H_ */