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>

diff --git a/Documentation/ABI/testing/sysfs-firmware-dmi-tables b/Documentation/ABI/testing/sysfs-firmware-dmi-tables
new file mode 100644 (file)
index 0000000..ff3cac8
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-firmware-dmi-tables
@@ -0,0 +1,22 @@
+What:          /sys/firmware/dmi/tables/
+Date:          April 2015
+Contact:       Ivan Khoronzhuk <ivan.khoronzhuk@globallogic.com>
+Description:
+               The firmware provides DMI structures as a packed list of
+               data referenced by a SMBIOS table entry point. The SMBIOS
+               entry point contains general information, like SMBIOS
+               version, DMI table size, etc. The structure, content and
+               size of SMBIOS entry point is dependent on SMBIOS version.
+               The format of SMBIOS entry point and DMI structures
+               can be read in SMBIOS specification.
+
+               The dmi/tables provides raw SMBIOS entry point and DMI tables
+               through sysfs as an alternative to utilities reading them
+               from /dev/mem. The raw SMBIOS entry point and DMI table are
+               presented as binary attributes and are accessible via:
+
+               /sys/firmware/dmi/tables/smbios_entry_point
+               /sys/firmware/dmi/tables/DMI
+
+               The complete DMI information can be obtained using these two
+               tables.

diff --git a/MAINTAINERS b/MAINTAINERS
index 0502f9a..ca47368 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3289,6 +3289,7 @@ DMI/SMBIOS SUPPORT
 M:     Jean Delvare <jdelvare@suse.de>
 S:     Maintained
 T:     quilt http://jdelvare.nerim.net/devel/linux/jdelvare-dmi/
+F:     Documentation/ABI/testing/sysfs-firmware-dmi-tables
 F:     drivers/firmware/dmi-id.c
 F:     drivers/firmware/dmi_scan.c
 F:     include/linux/dmi.h

diff --cc drivers/firmware/dmi-sysfs.c
Simple merge

diff --cc drivers/firmware/dmi_scan.c
Simple merge

diff --cc include/linux/dmi.h
Simple merge