arch/x86/smbios: Add support for table 38

Add support for SMBIOS table 'IPMI Device Information' and use it on
HP Compaq 8200 Elite SFF.

Tested on HP Compaq 8200. dmidecode prints the table and sensors-detect scans
for IPMI compatible devices.

Change-Id: I66b4c4658da9d44941430d8040384d022d76f51e
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/25386
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/smbios.c

@@ -4,6 +4,7 @@
  * Copyright (C) 2015 Timothy Pearson <tpearson@raptorengineeringinc.com>,
  * Raptor Engineering
  * Copyright (C) 2011 Sven Schnelle <svens@stackframe.org>
+ * Copyright (C) 2018 Patrick Rudolph <siro@das-labor.org>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
@@ -629,6 +630,33 @@ static int smbios_write_type32(unsigned long *current, int handle)
 	return len;
 }
 
+int smbios_write_type38(unsigned long *current, int *handle,
+			const enum smbios_bmc_interface_type interface_type,
+			const u8 ipmi_rev, const u8 i2c_addr, const u8 nv_addr,
+			const u64 base_addr, const u8 base_modifier,
+			const u8 irq)
+{
+	struct smbios_type38 *t = (struct smbios_type38 *)*current;
+	int len = sizeof(struct smbios_type38);
+
+	memset(t, 0, sizeof(struct smbios_type38));
+	t->type = SMBIOS_IPMI_DEVICE_INFORMATION;
+	t->handle = *handle;
+	t->length = len - 2;
+	t->interface_type = interface_type;
+	t->ipmi_rev = ipmi_rev;
+	t->i2c_slave_addr = i2c_addr;
+	t->nv_storage_addr = nv_addr;
+	t->base_address = base_addr;
+	t->base_address_modifier = base_modifier;
+	t->irq = irq;
+
+	*current += len;
+	*handle += 1;
+
+	return len;
+}
+
 int smbios_write_type41(unsigned long *current, int *handle,
 			const char *name, u8 instance, u16 segment,
 			u8 bus, u8 device, u8 function)