firmware/dmi: Report DMI Bios & EC firmware release

Some vendors like HPe or Dell, encode the release version of their BIOS
in the "System BIOS {Major|Minor} Release" fields of Type 0.

This information is used to know which bios release actually runs.
It could be used for some quirks, debugging sessions or inventory tasks.

A typical output for a Dell system running the 65.27 bios is :
	[root@t1700 ~]# cat /sys/devices/virtual/dmi/id/bios_release
	65.27
	[root@t1700 ~]#

Servers that have a BMC encode the release version of their firmware in the
 "Embedded Controller Firmware {Major|Minor} Release" fields of Type 0.

This information is used to know which BMC release actually runs.
It could be used for some quirks, debugging sessions or inventory tasks.

A typical output for a Dell system running the 3.75 bmc release is :
    [root@t1700 ~]# cat /sys/devices/virtual/dmi/id/ec_firmware_release
    3.75
    [root@t1700 ~]#

Signed-off-by: Erwan Velu <e.velu@criteo.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>

1 files changed, 30 insertions, 0 deletions

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index f59163cb7cba..5066d1f1d687 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -186,6 +186,34 @@ static void __init dmi_save_ident(const struct dmi_header *dm, int slot,
 	dmi_ident[slot] = p;
 }
 
+static void __init dmi_save_release(const struct dmi_header *dm, int slot,
+		int index)
+{
+	const u8 *minor, *major;
+	char *s;
+
+	/* If the table doesn't have the field, let's return */
+	if (dmi_ident[slot] || dm->length < index)
+		return;
+
+	minor = (u8 *) dm + index;
+	major = (u8 *) dm + index - 1;
+
+	/* As per the spec, if the system doesn't support this field,
+	 * the value is FF
+	 */
+	if (*major == 0xFF && *minor == 0xFF)
+		return;
+
+	s = dmi_alloc(8);
+	if (!s)
+		return;
+
+	sprintf(s, "%u.%u", *major, *minor);
+
+	dmi_ident[slot] = s;
+}
+
 static void __init dmi_save_uuid(const struct dmi_header *dm, int slot,
 		int index)
 {
@@ -444,6 +472,8 @@ static void __init dmi_decode(const struct dmi_header *dm, void *dummy)
 		dmi_save_ident(dm, DMI_BIOS_VENDOR, 4);
 		dmi_save_ident(dm, DMI_BIOS_VERSION, 5);
 		dmi_save_ident(dm, DMI_BIOS_DATE, 8);
+		dmi_save_release(dm, DMI_BIOS_RELEASE, 21);
+		dmi_save_release(dm, DMI_EC_FIRMWARE_RELEASE, 23);
 		break;
 	case 1:		/* System Information */
 		dmi_save_ident(dm, DMI_SYS_VENDOR, 4);