drm/nouveau/mxm: initial implementation of dcb sanitisation

The DCB table provided by the VBIOS on most MXM chips has a number of
entries which either need to be disabled, or modified according to the
MXM-SIS Output Device Descriptors.

The x86 vbios code usually takes care of this for us, however, with the
large number of laptops now with switchable graphics or optimus, a lot
of the time nouveau is responsible for POSTing the card instead - leaving
some fun situations like, plugging in a monitor and having nouveau decide
3 connectors actually just got plugged in..

No MXM-SIS fetching methods implemented yet.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

6 files changed, 561 insertions, 3 deletions

diff --git a/drivers/gpu/drm/nouveau/Makefile b/drivers/gpu/drm/nouveau/Makefile
index cdd9c3d0914..c152a03d287 100644
--- a/drivers/gpu/drm/nouveau/Makefile
+++ b/drivers/gpu/drm/nouveau/Makefile
@@ -11,7 +11,7 @@ nouveau-y := nouveau_drv.o nouveau_state.o nouveau_channel.o nouveau_mem.o \
              nouveau_display.o nouveau_connector.o nouveau_fbcon.o \
              nouveau_hdmi.o nouveau_dp.o nouveau_ramht.o \
 	     nouveau_pm.o nouveau_volt.o nouveau_perf.o nouveau_temp.o \
-	     nouveau_mm.o nouveau_vm.o \
+	     nouveau_mm.o nouveau_vm.o nouveau_mxm.o \
              nv04_timer.o \
              nv04_mc.o nv40_mc.o nv50_mc.o \
              nv04_fb.o nv10_fb.o nv30_fb.o nv40_fb.o nv50_fb.o nvc0_fb.o \
diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
index 35b18f4f7c4..1faa7d9ceb9 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bios.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
@@ -5382,6 +5382,9 @@ bit_table(struct drm_device *dev, u8 id, struct bit_entry *bit)
 	struct nvbios *bios = &dev_priv->vbios;
 	u8 entries, *entry;
 
+	if (bios->type != NVBIOS_BIT)
+		return -ENODEV;
+
 	entries = bios->data[bios->offset + 10];
 	entry   = &bios->data[bios->offset + 12];
 	while (entries--) {
@@ -5832,7 +5835,7 @@ dcb_table(struct drm_device *dev)
 	return NULL;
 }
 
-u8 *
+void *
 dcb_outp(struct drm_device *dev, u8 idx)
 {
 	u8 *dcb = dcb_table(dev);
@@ -6663,6 +6666,10 @@ nouveau_bios_init(struct drm_device *dev)
 	if (ret)
 		return ret;
 
+	ret = nouveau_mxm_init(dev);
+	if (ret)
+		return ret;
+
 	ret = parse_dcb_table(dev, bios);
 	if (ret)
 		return ret;
@@ -6703,5 +6710,6 @@ nouveau_bios_init(struct drm_device *dev)
 void
 nouveau_bios_takedown(struct drm_device *dev)
 {
+	nouveau_mxm_fini(dev);
 	nouveau_i2c_fini(dev);
 }
diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.h b/drivers/gpu/drm/nouveau/nouveau_bios.h
index 481e1f23f2f..32b911d38e9 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bios.h
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.h
@@ -315,7 +315,7 @@ struct nvbios {
 };
 
 void *dcb_table(struct drm_device *);
-u8 *dcb_outp(struct drm_device *, u8 idx);
+void *dcb_outp(struct drm_device *, u8 idx);
 int dcb_outp_foreach(struct drm_device *, void *data,
 		     int (*)(struct drm_device *, void *, int idx, u8 *outp));
 u8 *dcb_conntab(struct drm_device *);
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.c b/drivers/gpu/drm/nouveau/nouveau_drv.c
index e4485404892..e4a7cfe7898 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.c
@@ -124,6 +124,10 @@ MODULE_PARM_DESC(ctxfw, "Use external HUB/GPC ucode (fermi)\n");
 int nouveau_ctxfw;
 module_param_named(ctxfw, nouveau_ctxfw, int, 0400);
 
+MODULE_PARM_DESC(ctxfw, "Santise DCB table according to MXM-SIS\n");
+int nouveau_mxmdcb = 1;
+module_param_named(mxmdcb, nouveau_mxmdcb, int, 0400);
+
 int nouveau_fbpercrtc;
 #if 0
 module_param_named(fbpercrtc, nouveau_fbpercrtc, int, 0400);
diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.h b/drivers/gpu/drm/nouveau/nouveau_drv.h
index fb126c1508b..891c91b1488 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.h
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.h
@@ -793,6 +793,7 @@ struct drm_nouveau_private {
 	struct nouveau_vm *chan_vm;
 
 	struct nvbios vbios;
+	u8 *mxms;
 	struct list_head i2c_ports;
 
 	struct nv04_mode_state mode_reg;
@@ -864,6 +865,7 @@ extern char *nouveau_perflvl;
 extern int nouveau_perflvl_wr;
 extern int nouveau_msi;
 extern int nouveau_ctxfw;
+extern int nouveau_mxmdcb;
 
 extern int nouveau_pci_suspend(struct pci_dev *pdev, pm_message_t pm_state);
 extern int nouveau_pci_resume(struct pci_dev *pdev);
@@ -1108,6 +1110,10 @@ extern int call_lvds_script(struct drm_device *, struct dcb_entry *, int head,
 			    enum LVDS_script, int pxclk);
 bool bios_encoder_match(struct dcb_entry *, u32 hash);
 
+/* nouveau_mxm.c */
+int  nouveau_mxm_init(struct drm_device *dev);
+void nouveau_mxm_fini(struct drm_device *dev);
+
 /* nouveau_ttm.c */
 int nouveau_ttm_global_init(struct drm_nouveau_private *);
 void nouveau_ttm_global_release(struct drm_nouveau_private *);
diff --git a/drivers/gpu/drm/nouveau/nouveau_mxm.c b/drivers/gpu/drm/nouveau/nouveau_mxm.c
new file mode 100644
index 00000000000..ae9a5ac750f
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nouveau_mxm.c
@@ -0,0 +1,540 @@
+/*
+ * Copyright 2011 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+
+#include "drmP.h"
+#include "nouveau_drv.h"
+
+#define MXM_DBG(dev, fmt, args...) NV_DEBUG((dev), "MXM: " fmt, ##args)
+#define MXM_MSG(dev, fmt, args...) NV_INFO((dev), "MXM: " fmt, ##args)
+
+static u8 *
+mxms_data(struct drm_device *dev)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	return dev_priv->mxms;
+
+}
+
+static u16
+mxms_version(struct drm_device *dev)
+{
+	u8 *mxms = mxms_data(dev);
+	u16 version = (mxms[4] << 8) | mxms[5];
+	switch (version ) {
+	case 0x0200:
+	case 0x0201:
+	case 0x0300:
+		return version;
+	default:
+		break;
+	}
+
+	MXM_DBG(dev, "unknown version %d.%d\n", mxms[4], mxms[5]);
+	return 0x0000;
+}
+
+static u16
+mxms_headerlen(struct drm_device *dev)
+{
+	return 8;
+}
+
+static u16
+mxms_structlen(struct drm_device *dev)
+{
+	return *(u16 *)&mxms_data(dev)[6];
+}
+
+static bool
+mxms_checksum(struct drm_device *dev)
+{
+	u16 size = mxms_headerlen(dev) + mxms_structlen(dev);
+	u8 *mxms = mxms_data(dev), sum = 0;
+	while (size--)
+		sum += *mxms++;
+	if (sum) {
+		MXM_DBG(dev, "checksum invalid\n");
+		return false;
+	}
+	return true;
+}
+
+static bool
+mxms_valid(struct drm_device *dev)
+{
+	u8 *mxms = mxms_data(dev);
+	if (*(u32 *)mxms != 0x5f4d584d) {
+		MXM_DBG(dev, "signature invalid\n");
+		return false;
+	}
+
+	if (!mxms_version(dev) || !mxms_checksum(dev))
+		return false;
+
+	return true;
+}
+
+static bool
+mxms_foreach(struct drm_device *dev, u8 types,
+	     bool (*exec)(struct drm_device *, u8 *, void *), void *info)
+{
+	u8 *mxms = mxms_data(dev);
+	u8 *desc = mxms + mxms_headerlen(dev);
+	u8 *fini = desc + mxms_structlen(dev) - 1;
+	while (desc < fini) {
+		u8 type = desc[0] & 0x0f;
+		u8 headerlen = 0;
+		u8 recordlen = 0;
+		u8 entries = 0;
+
+		switch (type) {
+		case 0: /* Output Device Structure */
+			if (mxms_version(dev) >= 0x0300)
+				headerlen = 8;
+			else
+				headerlen = 6;
+			break;
+		case 1: /* System Cooling Capability Structure */
+		case 2: /* Thermal Structure */
+		case 3: /* Input Power Structure */
+			headerlen = 4;
+			break;
+		case 4: /* GPIO Device Structure */
+			headerlen = 4;
+			recordlen = 2;
+			entries   = (ROM32(desc[0]) & 0x01f00000) >> 20;
+			break;
+		case 5: /* Vendor Specific Structure */
+			headerlen = 8;
+			break;
+		case 6: /* Backlight Control Structure */
+			if (mxms_version(dev) >= 0x0300) {
+				headerlen = 4;
+				recordlen = 8;
+				entries   = (desc[1] & 0xf0) >> 4;
+			} else {
+				headerlen = 8;
+			}
+			break;
+		case 7: /* Fan Control Structure */
+			headerlen = 8;
+			recordlen = 4;
+			entries   = desc[1] & 0x07;
+			break;
+		default:
+			MXM_DBG(dev, "unknown descriptor type %d\n", type);
+			return false;
+		}
+
+		if ((drm_debug & DRM_UT_DRIVER) && (exec == NULL)) {
+			static const char * mxms_desc_name[] = {
+				"ODS", "SCCS", "TS", "IPS",
+				"GSD", "VSS", "BCS", "FCS",
+			};
+			u8 *dump = desc;
+			int i, j;
+
+			MXM_DBG(dev, "%4s: ", mxms_desc_name[type]);
+			for (j = headerlen - 1; j >= 0; j--)
+				printk("%02x", dump[j]);
+			printk("\n");
+			dump += headerlen;
+
+			for (i = 0; i < entries; i++, dump += recordlen) {
+				MXM_DBG(dev, "      ");
+				for (j = recordlen - 1; j >= 0; j--)
+					printk("%02x", dump[j]);
+				printk("\n");
+			}
+		}
+
+		if (types & (1 << type)) {
+			if (!exec(dev, desc, info))
+				return false;
+		}
+
+		desc += headerlen + (entries * recordlen);
+	}
+
+	return true;
+}
+
+static u8 *
+mxm_table(struct drm_device *dev, u8 *size)
+{
+	struct bit_entry x;
+
+	if (bit_table(dev, 'x', &x)) {
+		MXM_DBG(dev, "BIT 'x' table not present\n");
+		return NULL;
+	}
+
+	if (x.version != 1 || x.length < 3) {
+		MXM_MSG(dev, "BIT x table %d/%d unknown\n",
+			x.version, x.length);
+		return NULL;
+	}
+
+	*size = x.length;
+	return x.data;
+}
+
+/* These map MXM v2.x digital connection values to the appropriate SOR/link,
+ * hopefully they're correct for all boards within the same chipset...
+ *
+ * MXM v3.x VBIOS are nicer and provide pointers to these tables.
+ */
+static u8 nv84_sor_map[16] = {
+	0x00, 0x12, 0x22, 0x11, 0x32, 0x31, 0x11, 0x31,
+	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static u8 nv92_sor_map[16] = {
+	0x00, 0x12, 0x22, 0x11, 0x32, 0x31, 0x11, 0x31,
+	0x11, 0x31, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static u8 nv94_sor_map[16] = {
+	0x00, 0x14, 0x24, 0x11, 0x34, 0x31, 0x11, 0x31,
+	0x11, 0x31, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static u8 nv96_sor_map[16] = {
+	0x00, 0x14, 0x24, 0x00, 0x34, 0x00, 0x11, 0x31,
+	0x11, 0x31, 0x12, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static u8 nv98_sor_map[16] = {
+	0x00, 0x14, 0x12, 0x11, 0x00, 0x31, 0x11, 0x31,
+	0x11, 0x31, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+static u8
+mxm_sor_map(struct drm_device *dev, u8 conn)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	u8 len, *mxm = mxm_table(dev, &len);
+	if (mxm && len >= 6) {
+		u8 *map = ROMPTR(dev, mxm[4]);
+		if (map) {
+			if (map[0] == 0x10) {
+				if (conn < map[3])
+					return map[map[1] + conn];
+				return 0x00;
+			}
+
+			MXM_MSG(dev, "unknown sor map 0x%02x\n", map[0]);
+		}
+	}
+
+	if (dev_priv->chipset == 0x84 || dev_priv->chipset == 0x86)
+		return nv84_sor_map[conn];
+	if (dev_priv->chipset == 0x92)
+		return nv92_sor_map[conn];
+	if (dev_priv->chipset == 0x94)
+		return nv94_sor_map[conn];
+	if (dev_priv->chipset == 0x96)
+		return nv96_sor_map[conn];
+	if (dev_priv->chipset == 0x98)
+		return nv98_sor_map[conn];
+
+	MXM_MSG(dev, "missing sor map\n");
+	return 0x00;
+}
+
+static u8
+mxm_ddc_map(struct drm_device *dev, u8 port)
+{
+	u8 len, *mxm = mxm_table(dev, &len);
+	if (mxm && len >= 8) {
+		u8 *map = ROMPTR(dev, mxm[6]);
+		if (map) {
+			if (map[0] == 0x10) {
+				if (port < map[3])
+					return map[map[1] + port];
+				return 0x00;
+			}
+
+			MXM_MSG(dev, "unknown ddc map 0x%02x\n", map[0]);
+		}
+	}
+
+	/* v2.x: directly write port as dcb i2cidx */
+	return (port << 4) | port;
+}
+
+struct mxms_odev {
+	u8 outp_type;
+	u8 conn_type;
+	u8 ddc_port;
+	u8 dig_conn;
+};
+
+static void
+mxms_output_device(struct drm_device *dev, u8 *pdata, struct mxms_odev *desc)
+{
+	u64 data = ROM32(pdata[0]);
+	if (mxms_version(dev) >= 0x0300)
+		data |= (u64)ROM16(pdata[4]) << 32;
+
+	desc->outp_type = (data & 0x00000000000000f0ULL) >> 4;
+	desc->ddc_port  = (data & 0x0000000000000f00ULL) >> 8;
+	desc->conn_type = (data & 0x000000000001f000ULL) >> 12;
+	desc->dig_conn  = (data & 0x0000000000780000ULL) >> 19;
+}
+
+struct context {
+	u32 *outp;
+	struct mxms_odev desc;
+};
+
+static bool
+mxm_match_tmds_partner(struct drm_device *dev, u8 *data, void *info)
+{
+	struct context *ctx = info;
+	struct mxms_odev desc;
+
+	mxms_output_device(dev, data, &desc);
+	if (desc.outp_type == 2 &&
+	    desc.dig_conn == ctx->desc.dig_conn)
+		return false;
+	return true;
+}
+
+static bool
+mxm_match_dcb(struct drm_device *dev, u8 *data, void *info)
+{
+	struct context *ctx = info;
+	u64 desc = *(u64 *)data;
+
+	mxms_output_device(dev, data, &ctx->desc);
+
+	/* match dcb encoder type to mxm-ods device type */
+	if ((ctx->outp[0] & 0x0000000f) != ctx->desc.outp_type)
+		return true;
+
+	/* digital output, have some extra stuff to match here, there's a
+	 * table in the vbios that provides a mapping from the mxm digital
+	 * connection enum values to SOR/link
+	 */
+	if ((desc & 0x00000000000000f0) >= 0x20) {
+		/* check against sor index */
+		u8 link = mxm_sor_map(dev, ctx->desc.dig_conn);
+		if ((ctx->outp[0] & 0x0f000000) != (link & 0x0f) << 24)
+			return true;
+
+		/* check dcb entry has a compatible link field */
+		link = (link & 0x30) >> 4;
+		if ((link & ((ctx->outp[1] & 0x00000030) >> 4)) != link)
+			return true;
+	}
+
+	/* mark this descriptor accounted for by setting invalid device type,
+	 * except of course some manufactures don't follow specs properly and
+	 * we need to avoid killing off the TMDS function on DP connectors
+	 * if MXM-SIS is missing an entry for it.
+	 */
+	data[0] &= ~0xf0;
+	if (ctx->desc.outp_type == 6 && ctx->desc.conn_type == 6 &&
+	    mxms_foreach(dev, 0x01, mxm_match_tmds_partner, ctx)) {
+		data[0] |= 0x20; /* modify descriptor to match TMDS now */
+	} else {
+		data[0] |= 0xf0;
+	}
+
+	return false;
+}
+
+static int
+mxm_dcb_sanitise_entry(struct drm_device *dev, void *data, int idx, u8 *dcbe)
+{
+	struct context ctx = { .outp = (u32 *)dcbe };
+	u8 type, i2cidx, link;
+	u8 *conn;
+
+	/* look for an output device structure that matches this dcb entry.
+	 * if one isn't found, disable it.
+	 */
+	if (mxms_foreach(dev, 0x01, mxm_match_dcb, &ctx)) {
+		MXM_DBG(dev, "disable %d: 0x%08x 0x%08x\n",
+			idx, ctx.outp[0], ctx.outp[1]);
+		ctx.outp[0] |= 0x0000000f;
+		return 0;
+	}
+
+	/* modify the output's ddc/aux port, there's a pointer to a table
+	 * with the mapping from mxm ddc/aux port to dcb i2c_index in the
+	 * vbios mxm table
+	 */
+	i2cidx = mxm_ddc_map(dev, ctx.desc.ddc_port);
+	if ((ctx.outp[0] & 0x0000000f) != OUTPUT_DP)
+		i2cidx = (i2cidx & 0x0f) << 4;
+	else
+		i2cidx = (i2cidx & 0xf0);
+
+	if (i2cidx != 0xf0) {
+		ctx.outp[0] &= ~0x000000f0;
+		ctx.outp[0] |= i2cidx;
+	}
+
+	/* override dcb sorconf.link, based on what mxm data says */
+	switch (ctx.desc.outp_type) {
+	case 0x00: /* Analog CRT */
+	case 0x01: /* Analog TV/HDTV */
+		break;
+	default:
+		link = mxm_sor_map(dev, ctx.desc.dig_conn) & 0x30;
+		ctx.outp[1] &= ~0x00000030;
+		ctx.outp[1] |= link;
+		break;
+	}
+
+	/* we may need to fixup various other vbios tables based on what
+	 * the descriptor says the connector type should be.
+	 *
+	 * in a lot of cases, the vbios tables will claim DVI-I is possible,
+	 * and the mxm data says the connector is really HDMI.  another
+	 * common example is DP->eDP.
+	 */
+	conn = dcb_conn(dev, (ctx.outp[0] & 0x0000f000) >> 12);
+	type = conn[0];
+	switch (ctx.desc.conn_type) {
+	case 0x01: /* LVDS */
+		ctx.outp[1] |= 0x00000004; /* use_power_scripts */
+		/* XXX: modify default link width in LVDS table */
+		break;
+	case 0x02: /* HDMI */
+		type = DCB_CONNECTOR_HDMI_1;
+		break;
+	case 0x03: /* DVI-D */
+		type = DCB_CONNECTOR_DVI_D;
+		break;
+	case 0x0e: /* eDP, falls through to DPint */
+		ctx.outp[1] |= 0x00010000;
+	case 0x07: /* DP internal, wtf is this?? HP8670w */
+		ctx.outp[1] |= 0x00000004; /* use_power_scripts? */
+		type = DCB_CONNECTOR_eDP;
+		break;
+	default:
+		break;
+	}
+
+	if (mxms_version(dev) >= 0x0300)
+		conn[0] = type;
+
+	return 0;
+}
+
+static bool
+mxm_show_unmatched(struct drm_device *dev, u8 *data, void *info)
+{
+	u64 desc = *(u64 *)data;
+	if ((desc & 0xf0) != 0xf0)
+		MXM_MSG(dev, "unmatched output device 0x%016llx\n", desc);
+	return true;
+}
+
+static void
+mxm_dcb_sanitise(struct drm_device *dev)
+{
+	u8 *dcb = dcb_table(dev);
+	if (!dcb || dcb[0] != 0x40) {
+		MXM_DBG(dev, "unsupported DCB version\n");
+		return;
+	}
+
+	dcb_outp_foreach(dev, NULL, mxm_dcb_sanitise_entry);
+	mxms_foreach(dev, 0x01, mxm_show_unmatched, NULL);
+}
+
+static bool
+mxm_shadow_rom(struct drm_device *dev)
+{
+	return false;
+}
+
+static bool
+mxm_shadow_dsm(struct drm_device *dev)
+{
+	return false;
+}
+
+struct mxm_shadow_h {
+	const char *name;
+	bool (*exec)(struct drm_device *);
+} _mxm_shadow[] = {
+	{ "ROM", mxm_shadow_rom },
+	{ "DSM", mxm_shadow_dsm },
+	{}
+};
+
+static int
+mxm_shadow(struct drm_device *dev)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	struct mxm_shadow_h *shadow = _mxm_shadow;
+	do {
+		MXM_DBG(dev, "checking %s\n", shadow->name);
+		if (shadow->exec(dev)) {
+			if (mxms_valid(dev))
+				return 0;
+			kfree(dev_priv->mxms);
+			dev_priv->mxms = NULL;
+		}
+	} while ((++shadow)->name);
+	return -ENOENT;
+}
+
+int
+nouveau_mxm_init(struct drm_device *dev)
+{
+	u8 mxm_size, *mxm = mxm_table(dev, &mxm_size);
+	if (!mxm || !mxm[0]) {
+		MXM_MSG(dev, "no VBIOS data, nothing to do\n");
+		return 0;
+	}
+
+	MXM_MSG(dev, "BIOS version %d.%d\n", mxm[0] >> 4, mxm[0] & 0x0f);
+
+	if (mxm_shadow(dev)) {
+		MXM_MSG(dev, "failed to locate valid SIS\n");
+		return -EINVAL;
+	}
+
+	MXM_MSG(dev, "MXMS Version %d.%d\n",
+		mxms_version(dev) >> 8, mxms_version(dev) & 0xff);
+	mxms_foreach(dev, 0, NULL, NULL);
+
+	if (nouveau_mxmdcb)
+		mxm_dcb_sanitise(dev);
+	return 0;
+}
+
+void
+nouveau_mxm_fini(struct drm_device *dev)
+{
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
+	kfree(dev_priv->mxms);
+	dev_priv->mxms = NULL;
+}