firmware: dmi_scan: add SBMIOS entry and DMI tables

Some utils, like dmidecode and smbios, need to access SMBIOS entry
table area in order to get information like SMBIOS version, size, etc.
Currently it's done via /dev/mem. But for situation when /dev/mem
usage is disabled, the utils have to use dmi sysfs instead, which
doesn't represent SMBIOS entry and adds code/delay redundancy when direct
access for table is needed.

So this patch creates dmi/tables and adds SMBIOS entry point to allow
utils in question to work correctly without /dev/mem. Also patch adds
raw dmi table to simplify dmi table processing in user space, as
proposed by Jean Delvare.

Tested-by: Roy Franz <roy.franz@linaro.org>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@globallogic.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>

1 files changed, 8 insertions, 9 deletions

diff --git a/drivers/firmware/dmi-sysfs.c b/drivers/firmware/dmi-sysfs.c
index e0f1cb3d3598..ef76e5eecf0b 100644
--- a/drivers/firmware/dmi-sysfs.c
+++ b/drivers/firmware/dmi-sysfs.c
@@ -566,7 +566,6 @@ static struct kobj_type dmi_sysfs_entry_ktype = {
 	.default_attrs = dmi_sysfs_entry_attrs,
 };
 
-static struct kobject *dmi_kobj;
 static struct kset *dmi_kset;
 
 /* Global count of all instances seen.  Only for setup */
@@ -648,17 +647,20 @@ static void cleanup_entry_list(void)
 
 static int __init dmi_sysfs_init(void)
 {
-	int error = -ENOMEM;
+	int error;
 	int val;
 
-	/* Set up our directory */
-	dmi_kobj = kobject_create_and_add("dmi", firmware_kobj);
-	if (!dmi_kobj)
+	if (!dmi_kobj) {
+		pr_err("dmi-sysfs: dmi entry is absent.\n");
+		error = -ENODATA;
 		goto err;
+	}
 
 	dmi_kset = kset_create_and_add("entries", NULL, dmi_kobj);
-	if (!dmi_kset)
+	if (!dmi_kset) {
+		error = -ENOMEM;
 		goto err;
+	}
 
 	val = 0;
 	error = dmi_walk(dmi_sysfs_register_handle, &val);
@@ -675,7 +677,6 @@ static int __init dmi_sysfs_init(void)
 err:
 	cleanup_entry_list();
 	kset_unregister(dmi_kset);
-	kobject_put(dmi_kobj);
 	return error;
 }
 
@@ -685,8 +686,6 @@ static void __exit dmi_sysfs_exit(void)
 	pr_debug("dmi-sysfs: unloading.\n");
 	cleanup_entry_list();
 	kset_unregister(dmi_kset);
-	kobject_del(dmi_kobj);
-	kobject_put(dmi_kobj);
 }
 
 module_init(dmi_sysfs_init);