Following patch adds K8M890 support. It initializes the AGP and graphics UMA.

The V-link setup and HT bridge is redone, because VT8237A has it in another
device. So far following combination of chipsets should now work:

K8T890CE + VT8237R
K8M890(CE) + VT8237R

VIA PC1 brige moved to NB code (vt8237r_bridge.c -> k8t890_bridge.c) and
notes about K8M890 support were added.

Signed-off-by: Rudolf Marek <r.marek@assembler.cz>
Acked-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3183 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

10 files changed, 374 insertions, 74 deletions

diff --git a/src/southbridge/via/k8t890/Config.lb b/src/southbridge/via/k8t890/Config.lb
index 9699f4b0e5..27e80b92a7 100644
--- a/src/southbridge/via/k8t890/Config.lb
+++ b/src/southbridge/via/k8t890/Config.lb
@@ -19,6 +19,7 @@
 
 driver k8t890_ctrl.o
 driver k8t890_dram.o
+driver k8t890_bridge.o
 driver k8t890_host.o
 driver k8t890_host_ctrl.o
 driver k8t890_pcie.o
diff --git a/src/southbridge/via/k8t890/k8t890.h b/src/southbridge/via/k8t890/k8t890.h
index a9989dd704..63f8d20926 100644
--- a/src/southbridge/via/k8t890/k8t890.h
+++ b/src/southbridge/via/k8t890/k8t890.h
@@ -32,4 +32,7 @@
 #define K8T890_MMCONFIG_MBAR	0x61
 #define K8T890_MULTIPLE_FN_EN	0x4f
 
+/* the FB size in MB (min is 8MB max is 512MB) */
+#define K8M890_FBSIZEMB		64
+
 #endif
diff --git a/src/southbridge/via/k8t890/k8t890_bridge.c b/src/southbridge/via/k8t890/k8t890_bridge.c
new file mode 100644
index 0000000000..be1ba721ef
--- /dev/null
+++ b/src/southbridge/via/k8t890/k8t890_bridge.c
@@ -0,0 +1,63 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2007 Rudolf Marek <r.marek@assembler.cz>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License v2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <console/console.h>
+
+static void bridge_enable(struct device *dev)
+{
+	print_debug("B188 device dump\n");
+
+	/* VIA recommends this, sorry no known info. */
+
+	writeback(dev, 0x40, 0x91);
+	writeback(dev, 0x41, 0x40);
+	writeback(dev, 0x43, 0x44);
+	writeback(dev, 0x44, 0x31); 	/* K8M890 should have 0x35 datasheet 
+					 * says it is reserved 
+					 */
+	writeback(dev, 0x45, 0x3a);
+	writeback(dev, 0x46, 0x88);	/* PCI ID lo */
+	writeback(dev, 0x47, 0xb1);	/* PCI ID hi */
+
+	/* Bridge control, K8M890 bit 3 should be set to enable VGA on AGP 
+	 * (Forward VGA compatible memory and I/O cycles )
+	 */
+
+	writeback(dev, 0x3e, 0x16);
+	dump_south(dev);
+}
+
+static const struct device_operations bridge_ops = {
+	.read_resources		= pci_bus_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_bus_enable_resources,
+	.enable			= bridge_enable,
+	.scan_bus		= pci_scan_bridge,
+	.reset_bus		= pci_bus_reset,
+	.ops_pci		= 0,
+};
+
+static const struct pci_driver northbridge_driver __pci_driver = {
+	.ops	= &bridge_ops,
+	.vendor	= PCI_VENDOR_ID_VIA,
+	.device	= PCI_DEVICE_ID_VIA_K8T890CE_BR,
+};
diff --git a/src/southbridge/via/k8t890/k8t890_ctrl.c b/src/southbridge/via/k8t890/k8t890_ctrl.c
index 42f918f842..baf98405a6 100644
--- a/src/southbridge/via/k8t890/k8t890_ctrl.c
+++ b/src/southbridge/via/k8t890/k8t890_ctrl.c
@@ -23,6 +23,70 @@
 #include <device/pci_ids.h>
 #include <console/console.h>
 
+/* We support here K8M890/K8T890 and VT8237R PCI1/Vlink which setup is not in separate 
+ * PCI device 0:11.7, but it is mapped to PCI 0:0.7 (0x70-0x7c for PCI1)
+ */
+
+static void vt8237r_cfg(struct device *dev, struct device *devsb)
+{
+	u8 regm, regm2, regm3;
+
+	device_t devfun3;
+
+	devfun3 = dev_find_device(PCI_VENDOR_ID_VIA,
+					   PCI_DEVICE_ID_VIA_K8T890CE_3, 0);
+
+		if (!devfun3)
+			devfun3 = dev_find_device(PCI_VENDOR_ID_VIA,
+					   PCI_DEVICE_ID_VIA_K8M890CE_3, 0);
+
+	pci_write_config8(dev, 0x70, 0xc2);
+
+	/* PCI Control */
+	pci_write_config8(dev, 0x72, 0xee);
+	pci_write_config8(dev, 0x73, 0x01);
+	pci_write_config8(dev, 0x74, 0x24);
+	pci_write_config8(dev, 0x75, 0x0f);
+	pci_write_config8(dev, 0x76, 0x50);
+	pci_write_config8(dev, 0x77, 0x08);
+	pci_write_config8(dev, 0x78, 0x01);
+	/* APIC on HT */
+	pci_write_config8(dev, 0x7c, 0x7f);
+	pci_write_config8(dev, 0x7f, 0x02);
+
+	/* WARNING: Need to copy some registers from NB (D0F3) to SB (D0F7). */
+
+	regm = pci_read_config8(devfun3, 0x88);	/* Shadow mem CTRL */
+	pci_write_config8(dev, 0x57, regm);
+
+	regm = pci_read_config8(devfun3, 0x80);	/* Shadow page C */
+	pci_write_config8(dev, 0x61, regm);
+
+	regm = pci_read_config8(devfun3, 0x81);	/* Shadow page D */
+	pci_write_config8(dev, 0x62, regm);
+
+	regm = pci_read_config8(devfun3, 0x86);	/* SMM and APIC decoding */
+	pci_write_config8(dev, 0xe6, regm);
+
+	regm3 = pci_read_config8(devfun3, 0x82);/* Shadow page E */
+
+	/*
+	 * All access bits for 0xE0000-0xEFFFF encode as just 2 bits!
+	 * So the NB reg is quite inconsistent, we expect there only 0xff or 0x00,
+	 * and write them to 0x63 7-6 but! VIA 8237A has the mirror at 0x64!
+	 */
+	if (regm3 == 0xff)
+		regm3 = 0xc0;
+	else
+		regm3 = 0x0;
+
+	/* Shadow page F + memhole copy */
+	regm = pci_read_config8(devfun3, 0x83);
+	pci_write_config8(dev, 0x63, regm3 | (regm & 0x3F));
+}
+
+
+
 /**
  * Setup the V-Link for VT8237R, 8X mode.
  *
@@ -41,7 +105,8 @@
  * V-Link CKG Control				 0xb0  0x05  0x05  0x06  0x03
  * V-Link CKG Control				 0xb1  0x05  0x05  0x01  0x03
  */
-static void ctrl_init_vt8237r(struct device *dev)
+
+static void vt8237r_vlink_init(struct device *dev)
 {
 	u8 reg;
 
@@ -50,10 +115,6 @@ static void ctrl_init_vt8237r(struct device *dev)
 	 * sounthbridges (e.g. VT8237A, VT8237S, VT8237 (without plus R)
 	 * and VT8251) a different init code is required.
 	 */
-	device_t devsb = dev_find_device(PCI_VENDOR_ID_VIA,
-					 PCI_DEVICE_ID_VIA_VT8237R_LPC, 0);
-	if (!devsb)
-		return;
 
 	pci_write_config8(dev, 0xb5, 0x88);
 	pci_write_config8(dev, 0xb6, 0x88);
@@ -78,11 +139,7 @@ static void ctrl_init_vt8237r(struct device *dev)
 	pci_write_config8(dev, 0x48, 0xa3);
 }
 
-static void ctrl_enable(struct device *dev)
-{
-	u8 regm, regm2, regm3;
-	device_t devfun3 = dev_find_device(PCI_VENDOR_ID_VIA,
-					   PCI_DEVICE_ID_VIA_K8T890CE_3, 0);
+static void ctrl_init(struct device *dev) {
 
 	/* TODO: Fix some ordering issue fo V-link set Rx77[6] and PCI1_Rx4F[0]
 	   should to 1 */
@@ -90,64 +147,36 @@ static void ctrl_enable(struct device *dev)
 	/* C2P Read ACK Return Priority */
 	/* PCI CFG Address bits[27:24] are used as extended register address
 	   bit[11:8] */
-	pci_write_config8(dev, 0x47, 0x30);
-	/* Magic init. This is not well documented :/ */
-	pci_write_config8(dev, 0x70, 0xc2);
-
-	/* PCI Control */
-	pci_write_config8(dev, 0x72, 0xee);
-	pci_write_config8(dev, 0x73, 0x01);
-	pci_write_config8(dev, 0x74, 0x24);
-	pci_write_config8(dev, 0x75, 0x0f);
-	pci_write_config8(dev, 0x76, 0x50);
-	pci_write_config8(dev, 0x77, 0x08);
-	pci_write_config8(dev, 0x78, 0x01);
-	/* APIC on HT */
-	pci_write_config8(dev, 0x7c, 0x7f);
-	pci_write_config8(dev, 0x7f, 0x02);
-
-	/* WARNING: Need to copy some registers from NB (D0F3) to SB (D0F7). */
-
-	regm = pci_read_config8(devfun3, 0x88);	/* Shadow mem CTRL */
-	pci_write_config8(dev, 0x57, regm);
-
-	regm = pci_read_config8(devfun3, 0x80);	/* Shadow page C */
-	pci_write_config8(dev, 0x61, regm);
 
-	regm = pci_read_config8(devfun3, 0x81);	/* Shadow page D */
-	pci_write_config8(dev, 0x62, regm);
-
-	regm = pci_read_config8(devfun3, 0x86);	/* SMM and APIC decoding */
-	pci_write_config8(dev, 0xe6, regm);
+	pci_write_config8(dev, 0x47, 0x30);
 
-	regm3 = pci_read_config8(devfun3, 0x82);/* Shadow page E */
+	/* VT8237R specific configuration  other SB are done in their own directories */
 
-	/*
-	 * All access bits for 0xE0000-0xEFFFF encode as just 2 bits!
-	 * So the NB reg is quite inconsistent, we expect there only 0xff or 0x00,
-	 * and write them to 0x63 7-6 but! VIA 8237A has the mirror at 0x64!
-	 */
-	if (regm3 == 0xff)
-		regm3 = 0xc0;
-	else
-		regm3 = 0x0;
+	device_t devsb = dev_find_device(PCI_VENDOR_ID_VIA,
+					 PCI_DEVICE_ID_VIA_VT8237R_LPC, 0);
+	if (devsb) {
+		vt8237r_vlink_init(dev);
+		vt8237r_cfg(dev, devsb);
+	}
 
-	/* Shadow page F + memhole copy */
-	regm = pci_read_config8(devfun3, 0x83);
-	pci_write_config8(dev, 0x63, regm3 | (regm & 0x3F));
 }
 
 static const struct device_operations ctrl_ops = {
 	.read_resources		= pci_dev_read_resources,
 	.set_resources		= pci_dev_set_resources,
 	.enable_resources	= pci_dev_enable_resources,
-	.enable			= ctrl_enable,
-	.init			= ctrl_init_vt8237r,
+	.init			= ctrl_init,
 	.ops_pci		= 0,
 };
 
-static const struct pci_driver northbridge_driver __pci_driver = {
+static const struct pci_driver northbridge_driver_t __pci_driver = {
 	.ops	= &ctrl_ops,
 	.vendor	= PCI_VENDOR_ID_VIA,
 	.device	= PCI_DEVICE_ID_VIA_K8T890CE_7,
 };
+
+static const struct pci_driver northbridge_driver_m __pci_driver = {
+	.ops	= &ctrl_ops,
+	.vendor	= PCI_VENDOR_ID_VIA,
+	.device	= PCI_DEVICE_ID_VIA_K8M890CE_7,
+};
diff --git a/src/southbridge/via/k8t890/k8t890_dram.c b/src/southbridge/via/k8t890/k8t890_dram.c
index 38074220ae..00e5fa5f24 100644
--- a/src/southbridge/via/k8t890/k8t890_dram.c
+++ b/src/southbridge/via/k8t890/k8t890_dram.c
@@ -23,6 +23,8 @@
 #include <console/console.h>
 #include <cpu/x86/msr.h>
 #include <cpu/amd/mtrr.h>
+#include <bitops.h>
+#include "k8t890.h"
 
 static void dram_enable(struct device *dev)
 {
@@ -59,19 +61,99 @@ static void dram_enable(struct device *dev)
 	reg = pci_read_config16(dev, 0x88);
 	reg &= 0xf800;
 
+	/* The Address Next to the Last Valid DRAM Address */
 	pci_write_config16(dev, 0x88, (msr.lo >> 24) | reg);
 }
 
-static const struct device_operations dram_ops = {
+static struct resource *resmax;
+
+static void get_memres(void *gp, struct device *dev, struct resource *res)
+{
+	unsigned int *fbsize = (unsigned int *) gp;
+	uint64_t proposed_base = res->base + res->size - *fbsize;
+
+	printk_debug("get_memres: res->base=%llx res->size=%llx %d %d %d\n",
+			res->base, res->size, (res->size > *fbsize), 
+			(!(proposed_base & (*fbsize - 1))),
+			(proposed_base < ((uint64_t) 0xffffffff)));
+
+	/* if we fit and also align OK, and must be below 4GB */
+	if ((res->size > *fbsize) && (!(proposed_base & (*fbsize - 1))) && 
+		(proposed_base < ((uint64_t) 0xffffffff) )) {
+		resmax = res;
+	}
+}
+
+
+static void dram_init_fb(struct device *dev)
+{
+	/* Important bits:
+	 * Enable the internal GFX bit 7 of reg 0xa1 plus in same reg:
+	 * bits 6:4 X fbuffer size will be  2^(X+2) or 100 = 64MB, 101 = 128MB 
+	 * bits 3:0 BASE [31:28]
+	 * reg 0xa0 bits 7:1 BASE [27:21] bit0 enable CPU access
+	 */
+	u8 tmp;
+	uint64_t proposed_base;
+	unsigned int fbsize = (K8M890_FBSIZEMB * 1024 * 1024);
+
+	resmax = NULL;
+	search_global_resources(
+                IORESOURCE_MEM | IORESOURCE_CACHEABLE, IORESOURCE_MEM | IORESOURCE_CACHEABLE,
+                get_memres, (void *) &fbsize);
+
+	/* no space for FB */
+	if (!resmax) {
+		printk_err("VIA FB: no space for framebuffer in RAM\n");
+		return;
+	}
+
+	proposed_base = resmax->base + resmax->size - fbsize;
+	resmax->size -= fbsize;
+
+	printk_debug("VIA FB proposed base: %llx\n", proposed_base);
+
+	/* enable UMA but no FB */
+	pci_write_config8(dev, 0xa1, 0x80);
+
+	/* 27:21 goes to 7:1, 0 is enable CPU access */
+	tmp = (proposed_base >> 20) | 0x1;
+	pci_write_config8(dev, 0xa0, tmp);
+
+	/* 31:28 goes to 3:0 */
+	tmp = ((proposed_base >> 28) & 0xf);
+	tmp = ((log2(K8M890_FBSIZEMB) - 2) << 4);
+	tmp |= 0x80;
+	pci_write_config8(dev, 0xa1, tmp);
+
+	/* TODO K8 needs some UMA fine tuning too maybe call some generic routine here? */
+}
+
+static const struct device_operations dram_ops_t = {
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.enable			= dram_enable,
+	.ops_pci		= 0,
+};
+
+static const struct device_operations dram_ops_m = {
 	.read_resources		= pci_dev_read_resources,
 	.set_resources		= pci_dev_set_resources,
 	.enable_resources	= pci_dev_enable_resources,
 	.enable			= dram_enable,
+	.init			= dram_init_fb,
 	.ops_pci		= 0,
 };
 
-static const struct pci_driver northbridge_driver __pci_driver = {
-	.ops	= &dram_ops,
+static const struct pci_driver northbridge_driver_t __pci_driver = {
+	.ops	= &dram_ops_t,
 	.vendor	= PCI_VENDOR_ID_VIA,
 	.device	= PCI_DEVICE_ID_VIA_K8T890CE_3,
 };
+
+static const struct pci_driver northbridge_driver_m __pci_driver = {
+	.ops	= &dram_ops_m,
+	.vendor	= PCI_VENDOR_ID_VIA,
+	.device	= PCI_DEVICE_ID_VIA_K8M890CE_3,
+};
diff --git a/src/southbridge/via/k8t890/k8t890_error.c b/src/southbridge/via/k8t890/k8t890_error.c
index 1d3a1612fb..4464e16cd7 100644
--- a/src/southbridge/via/k8t890/k8t890_error.c
+++ b/src/southbridge/via/k8t890/k8t890_error.c
@@ -30,6 +30,8 @@ static void error_enable(struct device *dev)
 	 * bit7 - Parity Error/SERR# Report Through NMI
 	 */
 	pci_write_config8(dev, 0x58, 0x81);
+
+	/* TODO: enable AGP errors reporting on K8M890 */
 }
 
 static const struct device_operations error_ops = {
@@ -40,8 +42,14 @@ static const struct device_operations error_ops = {
 	.ops_pci		= 0,
 };
 
-static const struct pci_driver northbridge_driver __pci_driver = {
+static const struct pci_driver northbridge_driver_t __pci_driver = {
 	.ops	= &error_ops,
 	.vendor	= PCI_VENDOR_ID_VIA,
 	.device	= PCI_DEVICE_ID_VIA_K8T890CE_1,
 };
+
+static const struct pci_driver northbridge_driver_m __pci_driver = {
+	.ops	= &error_ops,
+	.vendor	= PCI_VENDOR_ID_VIA,
+	.device	= PCI_DEVICE_ID_VIA_K8M890CE_1,
+};
diff --git a/src/southbridge/via/k8t890/k8t890_host.c b/src/southbridge/via/k8t890/k8t890_host.c
index 2ab16f58a2..d91b8f3b95 100644
--- a/src/southbridge/via/k8t890/k8t890_host.c
+++ b/src/southbridge/via/k8t890/k8t890_host.c
@@ -28,9 +28,32 @@ static void host_enable(struct device *dev)
 {
 	/* Multiple function control */
 	pci_write_config8(dev, K8T890_MULTIPLE_FN_EN, 0x01);
+
+}
+
+
+static void host_init(struct device *dev)
+{
+	u8 reg;
+
+	/* AGP Capability Header Control */
+	reg = pci_read_config8(dev, 0x4d);
+	reg |= 0x20; /* GART access enabled by either D0F0 Rx90[8] or D1F0 Rx90[8] */
+	pci_write_config8(dev, 0x4d, reg);
+
+	/* GD Output Stagger Delay */
+	reg = pci_read_config8(dev, 0x42);
+	reg |= 0x10; /* AD[31:16] with 1ns */
+	pci_write_config8(dev, 0x42, reg);
+
+	/* AGP Control */
+	reg = pci_read_config8(dev, 0xbc);
+	reg |= 0x20; /* AGP Read Snoop DRAM Post-Write Buffer */
+	pci_write_config8(dev, 0xbc, reg);
+
 }
 
-static const struct device_operations host_ops = {
+static const struct device_operations host_ops_t = {
 	.read_resources		= pci_dev_read_resources,
 	.set_resources		= pci_dev_set_resources,
 	.enable_resources	= pci_dev_enable_resources,
@@ -38,8 +61,23 @@ static const struct device_operations host_ops = {
 	.ops_pci		= 0,
 };
 
-static const struct pci_driver northbridge_driver __pci_driver = {
-	.ops	= &host_ops,
+static const struct device_operations host_ops_m = {
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.enable			= host_enable,
+	.init			= host_init,
+	.ops_pci		= 0,
+};
+
+static const struct pci_driver northbridge_driver_t __pci_driver = {
+	.ops	= &host_ops_t,
 	.vendor	= PCI_VENDOR_ID_VIA,
 	.device	= PCI_DEVICE_ID_VIA_K8T890CE_0,
 };
+
+static const struct pci_driver northbridge_driver_m __pci_driver = {
+	.ops	= &host_ops_m,
+	.vendor	= PCI_VENDOR_ID_VIA,
+	.device	= PCI_DEVICE_ID_VIA_K8M890CE_0,
+};
diff --git a/src/southbridge/via/k8t890/k8t890_host_ctrl.c b/src/southbridge/via/k8t890/k8t890_host_ctrl.c
index 38b659cd0d..f2bc88ad65 100644
--- a/src/southbridge/via/k8t890/k8t890_host_ctrl.c
+++ b/src/southbridge/via/k8t890/k8t890_host_ctrl.c
@@ -23,8 +23,10 @@
 #include <device/pci_ids.h>
 #include <console/console.h>
 
+/* this may be later merged */
+
 /* This fine tunes the HT link settings, which were loaded by ROM strap. */
-static void host_ctrl_enable(struct device *dev)
+static void host_ctrl_enable_k8t890(struct device *dev)
 {
 	dump_south(dev);
 
@@ -48,6 +50,11 @@ static void host_ctrl_enable(struct device *dev)
 	/* Arbitration control 2 */
 	pci_write_config8(dev, 0xa6, 0x80);
 
+	/* this will be possibly removed, when I figure out
+	 * if the ROM SIP is good, second reason is that the 
+	 * unknown bits are AGP related, which are dummy on K8T890
+	 */
+
 	writeback(dev, 0xa0, 0x13);	/* Bit4 is reserved! */
 	writeback(dev, 0xa1, 0x8e);	/* Some bits are reserved. */
 	writeback(dev, 0xa2, 0x0e);	/* I/O NVRAM base 0xe00-0xeff disabled. */
@@ -78,16 +85,55 @@ static void host_ctrl_enable(struct device *dev)
 	dump_south(dev);
 }
 
-static const struct device_operations host_ctrl_ops = {
+/* This fine tunes the HT link settings, which were loaded by ROM strap. */
+static void host_ctrl_enable_k8m890(struct device *dev) {
+
+	/*
+	 * Set PCI to HT outstanding requests to 03.
+	 * Bit 4 32 AGP ADS Read Outstanding Request Number
+	 */
+	pci_write_config8(dev, 0xa0, 0x13);
+
+	/* Disable NVRAM and enable non-posted PCI writes. */
+	pci_write_config8(dev, 0xa1, 0x8e);
+
+	/*
+	 * NVRAM I/O base 0xe00-0xeff, but it is disabled.
+	 */
+
+	pci_write_config8(dev, 0xa2, 0x0e);
+	/* Arbitration control  */
+	pci_write_config8(dev, 0xa5, 0x3c);
+
+	/* Arbitration control 2 */
+	pci_write_config8(dev, 0xa6, 0x82);
+
+}
+
+static const struct device_operations host_ctrl_ops_t = {
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.enable			= host_ctrl_enable_k8t890,
+	.ops_pci		= 0,
+};
+
+static const struct device_operations host_ctrl_ops_m = {
 	.read_resources		= pci_dev_read_resources,
 	.set_resources		= pci_dev_set_resources,
 	.enable_resources	= pci_dev_enable_resources,
-	.enable			= host_ctrl_enable,
+	.enable			= host_ctrl_enable_k8m890,
 	.ops_pci		= 0,
 };
 
-static const struct pci_driver northbridge_driver __pci_driver = {
-	.ops	= &host_ctrl_ops,
+static const struct pci_driver northbridge_driver_t __pci_driver = {
+	.ops	= &host_ctrl_ops_t,
 	.vendor	= PCI_VENDOR_ID_VIA,
 	.device	= PCI_DEVICE_ID_VIA_K8T890CE_2,
 };
+
+static const struct pci_driver northbridge_driver_m __pci_driver = {
+	.ops	= &host_ctrl_ops_m,
+	.vendor	= PCI_VENDOR_ID_VIA,
+	.device	= PCI_DEVICE_ID_VIA_K8M890CE_2,
+};
diff --git a/src/southbridge/via/k8t890/k8t890_traf_ctrl.c b/src/southbridge/via/k8t890/k8t890_traf_ctrl.c
index 6596c3f94c..a61c56d155 100644
--- a/src/southbridge/via/k8t890/k8t890_traf_ctrl.c
+++ b/src/southbridge/via/k8t890/k8t890_traf_ctrl.c
@@ -68,15 +68,15 @@ static void apic_mmconfig_read_resources(device_t dev)
 	res->flags = IORESOURCE_MEM;
 }
 
-static void traf_ctrl_enable(struct device *dev)
+static void traf_ctrl_enable_generic(struct device *dev)
 {
 	volatile u32 *apic;
 	u32 data;
 
-	/* Enable D3F1-D3F3, no device2 redirect, enable just one device behind
+	/* no device2 redirect, enable just one device behind
 	 * bridge device 2 and device 3).
 	 */
-	pci_write_config8(dev, 0x60, 0x88);
+	pci_write_config8(dev, 0x60, 0x08);
 
 	/* Will enable MMCONFIG later. */
 	pci_write_config8(dev, 0x64, 0x23);
@@ -104,16 +104,46 @@ static void traf_ctrl_enable(struct device *dev)
 	apic[4] = (data & 0xF0FFFF) | (K8T890_APIC_ID << 24);
 }
 
-static const struct device_operations traf_ctrl_ops = {
+static void traf_ctrl_enable_k8m890(struct device *dev)
+{
+	traf_ctrl_enable_generic(dev);
+}
+
+static void traf_ctrl_enable_k8t890(struct device *dev)
+{
+	u8 reg;
+
+	traf_ctrl_enable_generic(dev);
+
+	/* Enable D3F1-D3F3 */
+	reg = pci_read_config8(dev, 0x60);
+	pci_write_config8(dev, 0x60, 0x80 | reg);
+}
+
+static const struct device_operations traf_ctrl_ops_m = {
 	.read_resources		= apic_mmconfig_read_resources,
 	.set_resources		= mmconfig_set_resources,
 	.enable_resources	= pci_dev_enable_resources,
-	.enable			= traf_ctrl_enable,
+	.enable			= traf_ctrl_enable_k8m890,
 	.ops_pci		= 0,
 };
 
-static const struct pci_driver northbridge_driver __pci_driver = {
-	.ops	= &traf_ctrl_ops,
+static const struct device_operations traf_ctrl_ops_t = {
+	.read_resources		= apic_mmconfig_read_resources,
+	.set_resources		= mmconfig_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.enable			= traf_ctrl_enable_k8t890,
+	.ops_pci		= 0,
+};
+
+static const struct pci_driver northbridge_driver_t __pci_driver = {
+	.ops	= &traf_ctrl_ops_t,
 	.vendor	= PCI_VENDOR_ID_VIA,
 	.device	= PCI_DEVICE_ID_VIA_K8T890CE_5,
 };
+
+static const struct pci_driver northbridge_driver_m __pci_driver = {
+	.ops	= &traf_ctrl_ops_m,
+	.vendor	= PCI_VENDOR_ID_VIA,
+	.device	= PCI_DEVICE_ID_VIA_K8M890CE_5,
+};
diff --git a/src/southbridge/via/k8t890/romstrap.inc b/src/southbridge/via/k8t890/romstrap.inc
index 68e2f6ef7f..9642aa4d5c 100644
--- a/src/southbridge/via/k8t890/romstrap.inc
+++ b/src/southbridge/via/k8t890/romstrap.inc
@@ -20,7 +20,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  */
 
-/* This file constructs the ROM strap table for K8T890. */
+/* This file constructs the ROM strap table for K8T890 and K8M890 */
 
 .section ".romstrap", "a", @progbits