drm/nouveau/disp: introduce object to track per-head functions/state

Primarily intended as a way to pass per-head state around during
supervisor handling, and share logic between NV50/GF119.

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

29 files changed, 351 insertions, 88 deletions

diff --git a/drivers/gpu/drm/nouveau/include/nvkm/engine/disp.h b/drivers/gpu/drm/nouveau/include/nvkm/engine/disp.h
index f17200ed3c72..a0892d6d9841 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/engine/disp.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/engine/disp.h
@@ -8,10 +8,7 @@ struct nvkm_disp {
 	const struct nvkm_disp_func *func;
 	struct nvkm_engine engine;
 
-	struct {
-		int nr;
-	} head;
-
+	struct list_head head;
 	struct list_head outp;
 	struct list_head conn;
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/Kbuild b/drivers/gpu/drm/nouveau/nvkm/engine/disp/Kbuild
index cbc7f673a5de..7062929260bc 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/Kbuild
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/Kbuild
@@ -14,6 +14,11 @@ nvkm-y += nvkm/engine/disp/gp100.o
 nvkm-y += nvkm/engine/disp/gp102.o
 nvkm-y += nvkm/engine/disp/vga.o
 
+nvkm-y += nvkm/engine/disp/head.o
+nvkm-y += nvkm/engine/disp/headnv04.o
+nvkm-y += nvkm/engine/disp/headnv50.o
+nvkm-y += nvkm/engine/disp/headgf119.o
+
 nvkm-y += nvkm/engine/disp/dacnv50.o
 nvkm-y += nvkm/engine/disp/piornv50.o
 nvkm-y += nvkm/engine/disp/sornv50.o
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/base.c
index 3e02a94c3072..8489d0246cb3 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/base.c
@@ -23,6 +23,7 @@
  */
 #include "priv.h"
 #include "conn.h"
+#include "head.h"
 #include "outp.h"
 
 #include <core/client.h>
@@ -249,6 +250,7 @@ nvkm_disp_oneinit(struct nvkm_engine *engine)
 	struct nvkm_bios *bios = disp->engine.subdev.device->bios;
 	struct nvkm_outp *outp, *outt, *pair;
 	struct nvkm_conn *conn;
+	struct nvkm_head *head;
 	struct nvbios_connE connE;
 	struct dcb_output dcbE;
 	u8  hpd = 0, ver, hdr;
@@ -375,8 +377,11 @@ nvkm_disp_oneinit(struct nvkm_engine *engine)
 	if (ret)
 		return ret;
 
-	return nvkm_event_init(&nvkm_disp_vblank_func, 1,
-			       disp->head.nr, &disp->vblank);
+	i = 0;
+	list_for_each_entry(head, &disp->head, head)
+		i = max(i, head->id + 1);
+
+	return nvkm_event_init(&nvkm_disp_vblank_func, 1, i, &disp->vblank);
 }
 
 static void *
@@ -405,6 +410,12 @@ nvkm_disp_dtor(struct nvkm_engine *engine)
 		nvkm_outp_del(&outp);
 	}
 
+	while (!list_empty(&disp->head)) {
+		struct nvkm_head *head =
+			list_first_entry(&disp->head, typeof(*head), head);
+		nvkm_head_del(&head);
+	}
+
 	return data;
 }
 
@@ -420,10 +431,10 @@ nvkm_disp = {
 
 int
 nvkm_disp_ctor(const struct nvkm_disp_func *func, struct nvkm_device *device,
-	       int index, int heads, struct nvkm_disp *disp)
+	       int index, struct nvkm_disp *disp)
 {
 	disp->func = func;
-	disp->head.nr = heads;
+	INIT_LIST_HEAD(&disp->head);
 	INIT_LIST_HEAD(&disp->outp);
 	INIT_LIST_HEAD(&disp->conn);
 	return nvkm_engine_ctor(&nvkm_disp, device, index, true, &disp->engine);
@@ -431,9 +442,9 @@ nvkm_disp_ctor(const struct nvkm_disp_func *func, struct nvkm_device *device,
 
 int
 nvkm_disp_new_(const struct nvkm_disp_func *func, struct nvkm_device *device,
-	       int index, int heads, struct nvkm_disp **pdisp)
+	       int index, struct nvkm_disp **pdisp)
 {
 	if (!(*pdisp = kzalloc(sizeof(**pdisp), GFP_KERNEL)))
 		return -ENOMEM;
-	return nvkm_disp_ctor(func, device, index, heads, *pdisp);
+	return nvkm_disp_ctor(func, device, index, *pdisp);
 }
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/basenv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/basenv50.c
index 83f152300ec0..f1d6b820d482 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/basenv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/basenv50.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "dmacnv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 #include <core/client.h>
@@ -50,7 +51,7 @@ nv50_disp_base_new(const struct nv50_disp_dmac_func *func,
 		nvif_ioctl(parent, "create disp base channel dma vers %d "
 				   "pushbuf %016llx head %d\n",
 			   args->v0.version, args->v0.pushbuf, args->v0.head);
-		if (args->v0.head > disp->base.head.nr)
+		if (!nvkm_head_find(&disp->base, args->v0.head))
 			return -EINVAL;
 		push = args->v0.pushbuf;
 		head = args->v0.head;
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c
index 82ff82d8c1ab..ab51121b7982 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/cursnv50.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "channv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 #include <core/client.h>
@@ -48,7 +49,7 @@ nv50_disp_curs_new(const struct nv50_disp_chan_func *func,
 	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, false))) {
 		nvif_ioctl(parent, "create disp cursor vers %d head %d\n",
 			   args->v0.version, args->v0.head);
-		if (args->v0.head > disp->base.head.nr)
+		if (!nvkm_head_find(&disp->base, args->v0.head))
 			return -EINVAL;
 		head = args->v0.head;
 	} else
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/g84.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/g84.c
index 0db964764ced..0de04221da48 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/g84.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/g84.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -30,6 +31,7 @@ g84_disp = {
 	.uevent = &nv50_disp_chan_uevent,
 	.super = nv50_disp_super,
 	.root = &g84_disp_root_oclass,
+	.head.new = nv50_head_new,
 	.head.vblank_init = nv50_disp_vblank_init,
 	.head.vblank_fini = nv50_disp_vblank_fini,
 	.head.scanoutpos = nv50_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/g94.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/g94.c
index 3f3cdbc3363a..8010d381bc7d 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/g94.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/g94.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -30,6 +31,7 @@ g94_disp = {
 	.uevent = &nv50_disp_chan_uevent,
 	.super = nv50_disp_super,
 	.root = &g94_disp_root_oclass,
+	.head.new = nv50_head_new,
 	.head.vblank_init = nv50_disp_vblank_init,
 	.head.vblank_fini = nv50_disp_vblank_fini,
 	.head.scanoutpos = nv50_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gf119.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gf119.c
index 8d1e535af208..59bf3f950eea 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gf119.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gf119.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 #include <subdev/bios.h>
@@ -364,55 +365,55 @@ gf119_disp_super(struct work_struct *work)
 		container_of(work, struct nv50_disp, supervisor);
 	struct nvkm_subdev *subdev = &disp->base.engine.subdev;
 	struct nvkm_device *device = subdev->device;
+	struct nvkm_head *head;
 	u32 mask[4];
-	int head;
 
 	nvkm_debug(subdev, "supervisor %d\n", ffs(disp->super));
-	for (head = 0; head < disp->base.head.nr; head++) {
-		mask[head] = nvkm_rd32(device, 0x6101d4 + (head * 0x800));
-		nvkm_debug(subdev, "head %d: %08x\n", head, mask[head]);
+	list_for_each_entry(head, &disp->base.head, head) {
+		mask[head->id] = nvkm_rd32(device, 0x6101d4 + (head->id * 0x800));
+		HEAD_DBG(head, "%08x", mask[head->id]);
 	}
 
 	if (disp->super & 0x00000001) {
 		nv50_disp_chan_mthd(disp->chan[0], NV_DBG_DEBUG);
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(mask[head] & 0x00001000))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(mask[head->id] & 0x00001000))
 				continue;
-			nvkm_debug(subdev, "supervisor 1.0 - head %d\n", head);
-			gf119_disp_intr_unk1_0(disp, head);
+			nvkm_debug(subdev, "supervisor 1.0 - head %d\n", head->id);
+			gf119_disp_intr_unk1_0(disp, head->id);
 		}
 	} else
 	if (disp->super & 0x00000002) {
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(mask[head] & 0x00001000))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(mask[head->id] & 0x00001000))
 				continue;
-			nvkm_debug(subdev, "supervisor 2.0 - head %d\n", head);
-			gf119_disp_intr_unk2_0(disp, head);
+			nvkm_debug(subdev, "supervisor 2.0 - head %d\n", head->id);
+			gf119_disp_intr_unk2_0(disp, head->id);
 		}
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(mask[head] & 0x00010000))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(mask[head->id] & 0x00010000))
 				continue;
-			nvkm_debug(subdev, "supervisor 2.1 - head %d\n", head);
-			gf119_disp_intr_unk2_1(disp, head);
+			nvkm_debug(subdev, "supervisor 2.1 - head %d\n", head->id);
+			gf119_disp_intr_unk2_1(disp, head->id);
 		}
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(mask[head] & 0x00001000))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(mask[head->id] & 0x00001000))
 				continue;
-			nvkm_debug(subdev, "supervisor 2.2 - head %d\n", head);
-			gf119_disp_intr_unk2_2(disp, head);
+			nvkm_debug(subdev, "supervisor 2.2 - head %d\n", head->id);
+			gf119_disp_intr_unk2_2(disp, head->id);
 		}
 	} else
 	if (disp->super & 0x00000004) {
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(mask[head] & 0x00001000))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(mask[head->id] & 0x00001000))
 				continue;
-			nvkm_debug(subdev, "supervisor 3.0 - head %d\n", head);
-			gf119_disp_intr_unk4_0(disp, head);
+			nvkm_debug(subdev, "supervisor 3.0 - head %d\n", head->id);
+			gf119_disp_intr_unk4_0(disp, head->id);
 		}
 	}
 
-	for (head = 0; head < disp->base.head.nr; head++)
-		nvkm_wr32(device, 0x6101d4 + (head * 0x800), 0x00000000);
+	list_for_each_entry(head, &disp->base.head, head)
+		nvkm_wr32(device, 0x6101d4 + (head->id * 0x800), 0x00000000);
 	nvkm_wr32(device, 0x6101d0, 0x80000000);
 }
 
@@ -447,8 +448,8 @@ gf119_disp_intr(struct nv50_disp *disp)
 {
 	struct nvkm_subdev *subdev = &disp->base.engine.subdev;
 	struct nvkm_device *device = subdev->device;
+	struct nvkm_head *head;
 	u32 intr = nvkm_rd32(device, 0x610088);
-	int i;
 
 	if (intr & 0x00000001) {
 		u32 stat = nvkm_rd32(device, 0x61008c);
@@ -485,14 +486,15 @@ gf119_disp_intr(struct nv50_disp *disp)
 		intr &= ~0x00100000;
 	}
 
-	for (i = 0; i < disp->base.head.nr; i++) {
-		u32 mask = 0x01000000 << i;
+	list_for_each_entry(head, &disp->base.head, head) {
+		const u32 hoff = head->id * 0x800;
+		u32 mask = 0x01000000 << head->id;
 		if (mask & intr) {
-			u32 stat = nvkm_rd32(device, 0x6100bc + (i * 0x800));
+			u32 stat = nvkm_rd32(device, 0x6100bc + hoff);
 			if (stat & 0x00000001)
-				nvkm_disp_vblank(&disp->base, i);
-			nvkm_mask(device, 0x6100bc + (i * 0x800), 0, 0);
-			nvkm_rd32(device, 0x6100c0 + (i * 0x800));
+				nvkm_disp_vblank(&disp->base, head->id);
+			nvkm_mask(device, 0x6100bc + hoff, 0, 0);
+			nvkm_rd32(device, 0x6100c0 + hoff);
 		}
 	}
 }
@@ -512,6 +514,7 @@ gf119_disp = {
 	.uevent = &gf119_disp_chan_uevent,
 	.super = gf119_disp_super,
 	.root = &gf119_disp_root_oclass,
+	.head.new = gf119_head_new,
 	.head.vblank_init = gf119_disp_vblank_init,
 	.head.vblank_fini = gf119_disp_vblank_fini,
 	.head.scanoutpos = gf119_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk104.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk104.c
index ec14cef92de5..89561496570b 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk104.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk104.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -31,6 +32,7 @@ gk104_disp = {
 	.uevent = &gf119_disp_chan_uevent,
 	.super = gf119_disp_super,
 	.root = &gk104_disp_root_oclass,
+	.head.new = gf119_head_new,
 	.head.vblank_init = gf119_disp_vblank_init,
 	.head.vblank_fini = gf119_disp_vblank_fini,
 	.head.scanoutpos = gf119_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk110.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk110.c
index 88f977660e41..9400d2ad79b9 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk110.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gk110.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -31,6 +32,7 @@ gk110_disp = {
 	.uevent = &gf119_disp_chan_uevent,
 	.super = gf119_disp_super,
 	.root = &gk110_disp_root_oclass,
+	.head.new = gf119_head_new,
 	.head.vblank_init = gf119_disp_vblank_init,
 	.head.vblank_fini = gf119_disp_vblank_fini,
 	.head.scanoutpos = gf119_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm107.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm107.c
index 5d7a2f42a4f0..b7570fb0fb1f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm107.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm107.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -31,6 +32,7 @@ gm107_disp = {
 	.uevent = &gf119_disp_chan_uevent,
 	.super = gf119_disp_super,
 	.root = &gm107_disp_root_oclass,
+	.head.new = gf119_head_new,
 	.head.vblank_init = gf119_disp_vblank_init,
 	.head.vblank_fini = gf119_disp_vblank_fini,
 	.head.scanoutpos = gf119_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm200.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm200.c
index 54fa9ebe346b..b3e52080d4b7 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm200.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gm200.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -31,6 +32,7 @@ gm200_disp = {
 	.uevent = &gf119_disp_chan_uevent,
 	.super = gf119_disp_super,
 	.root = &gm200_disp_root_oclass,
+	.head.new = gf119_head_new,
 	.head.vblank_init = gf119_disp_vblank_init,
 	.head.vblank_fini = gf119_disp_vblank_fini,
 	.head.scanoutpos = gf119_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp100.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp100.c
index 6f4e56d82421..3d1c65ff5620 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp100.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs <bskeggs@redhat.com>
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -31,6 +32,7 @@ gp100_disp = {
 	.uevent = &gf119_disp_chan_uevent,
 	.super = gf119_disp_super,
 	.root = &gp100_disp_root_oclass,
+	.head.new = gf119_head_new,
 	.head.vblank_init = gf119_disp_vblank_init,
 	.head.vblank_fini = gf119_disp_vblank_fini,
 	.head.scanoutpos = gf119_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp102.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp102.c
index 54b97e1dce0b..fac8e88fd2d1 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp102.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gp102.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs <bskeggs@redhat.com>
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static void
@@ -57,6 +58,7 @@ gp102_disp = {
 	.uevent = &gf119_disp_chan_uevent,
 	.super = gf119_disp_super,
 	.root = &gp102_disp_root_oclass,
+	.head.new = gf119_head_new,
 	.head.vblank_init = gf119_disp_vblank_init,
 	.head.vblank_fini = gf119_disp_vblank_fini,
 	.head.scanoutpos = gf119_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt200.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt200.c
index da6c395050de..a0e7c3c78e97 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt200.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt200.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -30,6 +31,7 @@ gt200_disp = {
 	.uevent = &nv50_disp_chan_uevent,
 	.super = nv50_disp_super,
 	.root = &gt200_disp_root_oclass,
+	.head.new = nv50_head_new,
 	.head.vblank_init = nv50_disp_vblank_init,
 	.head.vblank_fini = nv50_disp_vblank_fini,
 	.head.scanoutpos = nv50_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt215.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt215.c
index 1f475cf284e3..5f8a8d855673 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt215.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/gt215.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 static const struct nv50_disp_func
@@ -30,6 +31,7 @@ gt215_disp = {
 	.uevent = &nv50_disp_chan_uevent,
 	.super = nv50_disp_super,
 	.root = &gt215_disp_root_oclass,
+	.head.new = nv50_head_new,
 	.head.vblank_init = nv50_disp_vblank_init,
 	.head.vblank_fini = nv50_disp_vblank_fini,
 	.head.scanoutpos = nv50_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/head.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/head.c
new file mode 100644
index 000000000000..67020933f4ff
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/head.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2017 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 <bskeggs@redhat.com>
+ */
+#include "head.h"
+
+struct nvkm_head *
+nvkm_head_find(struct nvkm_disp *disp, int id)
+{
+	struct nvkm_head *head;
+	list_for_each_entry(head, &disp->head, head) {
+		if (head->id == id)
+			return head;
+	}
+	return NULL;
+}
+
+void
+nvkm_head_del(struct nvkm_head **phead)
+{
+	struct nvkm_head *head = *phead;
+	if (head) {
+		HEAD_DBG(head, "dtor");
+		list_del(&head->head);
+		kfree(*phead);
+		*phead = NULL;
+	}
+}
+
+int
+nvkm_head_new_(const struct nvkm_head_func *func,
+	       struct nvkm_disp *disp, int id)
+{
+	struct nvkm_head *head;
+	if (!(head = kzalloc(sizeof(*head), GFP_KERNEL)))
+		return -ENOMEM;
+	head->func = func;
+	head->disp = disp;
+	head->id = id;
+	list_add_tail(&head->head, &disp->head);
+	HEAD_DBG(head, "ctor");
+	return 0;
+}
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/head.h b/drivers/gpu/drm/nouveau/nvkm/engine/disp/head.h
new file mode 100644
index 000000000000..a8ae6cbc0ff1
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/head.h
@@ -0,0 +1,30 @@
+#ifndef __NVKM_DISP_HEAD_H__
+#define __NVKM_DISP_HEAD_H__
+#include "priv.h"
+
+struct nvkm_head {
+	const struct nvkm_head_func *func;
+	struct nvkm_disp *disp;
+	int id;
+
+	struct list_head head;
+};
+
+int nvkm_head_new_(const struct nvkm_head_func *, struct nvkm_disp *, int id);
+void nvkm_head_del(struct nvkm_head **);
+struct nvkm_head *nvkm_head_find(struct nvkm_disp *, int id);
+
+struct nvkm_head_func {
+};
+
+#define HEAD_MSG(h,l,f,a...) do {                                              \
+	struct nvkm_head *_h = (h);                                            \
+	nvkm_##l(&_h->disp->engine.subdev, "head-%d: "f"\n", _h->id, ##a);     \
+} while(0)
+#define HEAD_WARN(h,f,a...) HEAD_MSG((h), warn, f, ##a)
+#define HEAD_DBG(h,f,a...) HEAD_MSG((h), debug, f, ##a)
+
+int nv04_head_new(struct nvkm_disp *, int id);
+int nv50_head_new(struct nvkm_disp *, int id);
+int gf119_head_new(struct nvkm_disp *, int id);
+#endif
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/headgf119.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/headgf119.c
new file mode 100644
index 000000000000..062fa07e1ece
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/headgf119.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017 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 <bskeggs@redhat.com>
+ */
+#include "head.h"
+
+static const struct nvkm_head_func
+gf119_head = {
+};
+
+int
+gf119_head_new(struct nvkm_disp *disp, int id)
+{
+	return nvkm_head_new_(&gf119_head, disp, id);
+}
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/headnv04.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/headnv04.c
new file mode 100644
index 000000000000..f581327f695c
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/headnv04.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017 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 <bskeggs@redhat.com>
+ */
+#include "head.h"
+
+static const struct nvkm_head_func
+nv04_head = {
+};
+
+int
+nv04_head_new(struct nvkm_disp *disp, int id)
+{
+	return nvkm_head_new_(&nv04_head, disp, id);
+}
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/headnv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/headnv50.c
new file mode 100644
index 000000000000..e48865c91046
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/headnv50.c
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2017 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 <bskeggs@redhat.com>
+ */
+#include "head.h"
+
+static const struct nvkm_head_func
+nv50_head = {
+};
+
+int
+nv50_head_new(struct nvkm_disp *disp, int id)
+{
+	return nvkm_head_new_(&nv50_head, disp, id);
+}
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv04.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv04.c
index 67254ce6f83f..978e3ad488d9 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv04.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv04.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "priv.h"
+#include "head.h"
 
 static const struct nvkm_disp_oclass *
 nv04_disp_root(struct nvkm_disp *disp)
@@ -81,5 +82,17 @@ nv04_disp = {
 int
 nv04_disp_new(struct nvkm_device *device, int index, struct nvkm_disp **pdisp)
 {
-	return nvkm_disp_new_(&nv04_disp, device, index, 2, pdisp);
+	int ret, i;
+
+	ret = nvkm_disp_new_(&nv04_disp, device, index, pdisp);
+	if (ret)
+		return ret;
+
+	for (i = 0; i < 2; i++) {
+		ret = nv04_head_new(*pdisp, i);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c
index 025cc0d7feb3..9787a4cc4cce 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "nv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 #include <core/client.h>
@@ -146,7 +147,7 @@ nv50_disp_new_(const struct nv50_disp_func *func, struct nvkm_device *device,
 	       int index, int heads, struct nvkm_disp **pdisp)
 {
 	struct nv50_disp *disp;
-	int ret;
+	int ret, i;
 
 	if (!(disp = kzalloc(sizeof(*disp), GFP_KERNEL)))
 		return -ENOMEM;
@@ -154,10 +155,16 @@ nv50_disp_new_(const struct nv50_disp_func *func, struct nvkm_device *device,
 	disp->func = func;
 	*pdisp = &disp->base;
 
-	ret = nvkm_disp_ctor(&nv50_disp_, device, index, heads, &disp->base);
+	ret = nvkm_disp_ctor(&nv50_disp_, device, index, &disp->base);
 	if (ret)
 		return ret;
 
+	for (i = 0; func->head.new && i < heads; i++) {
+		ret = func->head.new(&disp->base, i);
+		if (ret)
+			return ret;
+	}
+
 	return nvkm_event_init(func->uevent, 1, 1 + (heads * 4), &disp->uevent);
 }
 
@@ -684,43 +691,43 @@ nv50_disp_super(struct work_struct *work)
 		container_of(work, struct nv50_disp, supervisor);
 	struct nvkm_subdev *subdev = &disp->base.engine.subdev;
 	struct nvkm_device *device = subdev->device;
+	struct nvkm_head *head;
 	u32 super = nvkm_rd32(device, 0x610030);
-	int head;
 
 	nvkm_debug(subdev, "supervisor %08x %08x\n", disp->super, super);
 
 	if (disp->super & 0x00000010) {
 		nv50_disp_chan_mthd(disp->chan[0], NV_DBG_DEBUG);
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(super & (0x00000020 << head)))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(super & (0x00000020 << head->id)))
 				continue;
-			if (!(super & (0x00000080 << head)))
+			if (!(super & (0x00000080 << head->id)))
 				continue;
-			nv50_disp_intr_unk10_0(disp, head);
+			nv50_disp_intr_unk10_0(disp, head->id);
 		}
 	} else
 	if (disp->super & 0x00000020) {
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(super & (0x00000080 << head)))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(super & (0x00000080 << head->id)))
 				continue;
-			nv50_disp_intr_unk20_0(disp, head);
+			nv50_disp_intr_unk20_0(disp, head->id);
 		}
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(super & (0x00000200 << head)))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(super & (0x00000200 << head->id)))
 				continue;
-			nv50_disp_intr_unk20_1(disp, head);
+			nv50_disp_intr_unk20_1(disp, head->id);
 		}
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(super & (0x00000080 << head)))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(super & (0x00000080 << head->id)))
 				continue;
-			nv50_disp_intr_unk20_2(disp, head);
+			nv50_disp_intr_unk20_2(disp, head->id);
 		}
 	} else
 	if (disp->super & 0x00000040) {
-		for (head = 0; head < disp->base.head.nr; head++) {
-			if (!(super & (0x00000080 << head)))
+		list_for_each_entry(head, &disp->base.head, head) {
+			if (!(super & (0x00000080 << head->id)))
 				continue;
-			nv50_disp_intr_unk40_0(disp, head);
+			nv50_disp_intr_unk40_0(disp, head->id);
 		}
 		nv50_disp_update_sppll1(disp);
 	}
@@ -819,6 +826,7 @@ nv50_disp = {
 	.uevent = &nv50_disp_chan_uevent,
 	.super = nv50_disp_super,
 	.root = &nv50_disp_root_oclass,
+	.head.new = nv50_head_new,
 	.head.vblank_init = nv50_disp_vblank_init,
 	.head.vblank_fini = nv50_disp_vblank_fini,
 	.head.scanoutpos = nv50_disp_root_scanoutpos,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.h b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.h
index 4fa82f48429b..0361f0c2ba1a 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/nv50.h
@@ -75,6 +75,7 @@ struct nv50_disp_func {
 	const struct nvkm_disp_oclass *root;
 
 	struct {
+		int (*new)(struct nvkm_disp *, int id);
 		void (*vblank_init)(struct nv50_disp *, int head);
 		void (*vblank_fini)(struct nv50_disp *, int head);
 		int (*scanoutpos)(NV50_DISP_MTHD_V0);
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/oimmnv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/oimmnv50.c
index 07540f3d32dc..f3b0fa2c5924 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/oimmnv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/oimmnv50.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "channv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 #include <core/client.h>
@@ -48,7 +49,7 @@ nv50_disp_oimm_new(const struct nv50_disp_chan_func *func,
 	if (!(ret = nvif_unpack(ret, &data, &size, args->v0, 0, 0, false))) {
 		nvif_ioctl(parent, "create disp overlay vers %d head %d\n",
 			   args->v0.version, args->v0.head);
-		if (args->v0.head > disp->base.head.nr)
+		if (!nvkm_head_find(&disp->base, args->v0.head))
 			return -EINVAL;
 		head = args->v0.head;
 	} else
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/ovlynv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/ovlynv50.c
index 2a49c46425cd..9ebaaa6e9e33 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/ovlynv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/ovlynv50.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "dmacnv50.h"
+#include "head.h"
 #include "rootnv50.h"
 
 #include <core/client.h>
@@ -50,7 +51,7 @@ nv50_disp_ovly_new(const struct nv50_disp_dmac_func *func,
 		nvif_ioctl(parent, "create disp overlay channel dma vers %d "
 				   "pushbuf %016llx head %d\n",
 			   args->v0.version, args->v0.pushbuf, args->v0.head);
-		if (args->v0.head > disp->base.head.nr)
+		if (!nvkm_head_find(&disp->base, args->v0.head))
 			return -EINVAL;
 		push = args->v0.pushbuf;
 		head = args->v0.head;
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/priv.h b/drivers/gpu/drm/nouveau/nvkm/engine/disp/priv.h
index e143fc7bc15f..4bb05a09a60b 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/priv.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/priv.h
@@ -4,9 +4,9 @@
 #include "outp.h"
 
 int nvkm_disp_ctor(const struct nvkm_disp_func *, struct nvkm_device *,
-		   int index, int heads, struct nvkm_disp *);
+		   int index, struct nvkm_disp *);
 int nvkm_disp_new_(const struct nvkm_disp_func *, struct nvkm_device *,
-		   int index, int heads, struct nvkm_disp **);
+		   int index, struct nvkm_disp **);
 void nvkm_disp_vblank(struct nvkm_disp *, int head);
 
 struct nvkm_disp_func_outp {
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootgf119.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootgf119.c
index 335d88823c22..f1159dd4db87 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootgf119.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootgf119.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "rootnv50.h"
+#include "head.h"
 #include "dmacnv50.h"
 
 #include <core/client.h>
@@ -78,6 +79,7 @@ int
 gf119_disp_root_init(struct nv50_disp_root *root)
 {
 	struct nv50_disp *disp = root->disp;
+	struct nvkm_head *head;
 	struct nvkm_device *device = disp->base.engine.subdev.device;
 	u32 tmp;
 	int i;
@@ -88,13 +90,14 @@ gf119_disp_root_init(struct nv50_disp_root *root)
 	 */
 
 	/* ... CRTC caps */
-	for (i = 0; i < disp->base.head.nr; i++) {
-		tmp = nvkm_rd32(device, 0x616104 + (i * 0x800));
-		nvkm_wr32(device, 0x6101b4 + (i * 0x800), tmp);
-		tmp = nvkm_rd32(device, 0x616108 + (i * 0x800));
-		nvkm_wr32(device, 0x6101b8 + (i * 0x800), tmp);
-		tmp = nvkm_rd32(device, 0x61610c + (i * 0x800));
-		nvkm_wr32(device, 0x6101bc + (i * 0x800), tmp);
+	list_for_each_entry(head, &disp->base.head, head) {
+		const u32 hoff = head->id * 0x800;
+		tmp = nvkm_rd32(device, 0x616104 + hoff);
+		nvkm_wr32(device, 0x6101b4 + hoff, tmp);
+		tmp = nvkm_rd32(device, 0x616108 + hoff);
+		nvkm_wr32(device, 0x6101b8 + hoff, tmp);
+		tmp = nvkm_rd32(device, 0x61610c + hoff);
+		nvkm_wr32(device, 0x6101bc + hoff, tmp);
 	}
 
 	/* ... DAC caps */
@@ -134,8 +137,10 @@ gf119_disp_root_init(struct nv50_disp_root *root)
 	 *
 	 * ftp://download.nvidia.com/open-gpu-doc/gk104-disable-underflow-reporting/1/gk104-disable-underflow-reporting.txt
 	 */
-	for (i = 0; i < disp->base.head.nr; i++)
-		nvkm_mask(device, 0x616308 + (i * 0x800), 0x00000111, 0x00000010);
+	list_for_each_entry(head, &disp->base.head, head) {
+		const u32 hoff = head->id * 0x800;
+		nvkm_mask(device, 0x616308 + hoff, 0x00000111, 0x00000010);
+	}
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootnv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootnv50.c
index 2e73aeb86070..b5df4e8ddbfd 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootnv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/disp/rootnv50.c
@@ -23,6 +23,7 @@
  */
 #include "rootnv50.h"
 #include "dmacnv50.h"
+#include "head.h"
 
 #include <core/client.h>
 #include <core/ramht.h>
@@ -102,7 +103,7 @@ nv50_disp_root_mthd_(struct nvkm_object *object, u32 mthd, void *data, u32 size)
 	} else
 		return ret;
 
-	if (head < 0 || head >= disp->base.head.nr)
+	if (!nvkm_head_find(&disp->base, head))
 		return -ENXIO;
 
 	if (mask) {
@@ -351,6 +352,7 @@ int
 nv50_disp_root_init(struct nv50_disp_root *root)
 {
 	struct nv50_disp *disp = root->disp;
+	struct nvkm_head *head;
 	struct nvkm_device *device = disp->base.engine.subdev.device;
 	u32 tmp;
 	int i;
@@ -363,15 +365,15 @@ nv50_disp_root_init(struct nv50_disp_root *root)
 	nvkm_wr32(device, 0x610184, tmp);
 
 	/* ... CRTC caps */
-	for (i = 0; i < disp->base.head.nr; i++) {
-		tmp = nvkm_rd32(device, 0x616100 + (i * 0x800));
-		nvkm_wr32(device, 0x610190 + (i * 0x10), tmp);
-		tmp = nvkm_rd32(device, 0x616104 + (i * 0x800));
-		nvkm_wr32(device, 0x610194 + (i * 0x10), tmp);
-		tmp = nvkm_rd32(device, 0x616108 + (i * 0x800));
-		nvkm_wr32(device, 0x610198 + (i * 0x10), tmp);
-		tmp = nvkm_rd32(device, 0x61610c + (i * 0x800));
-		nvkm_wr32(device, 0x61019c + (i * 0x10), tmp);
+	list_for_each_entry(head, &disp->base.head, head) {
+		tmp = nvkm_rd32(device, 0x616100 + (head->id * 0x800));
+		nvkm_wr32(device, 0x610190 + (head->id * 0x10), tmp);
+		tmp = nvkm_rd32(device, 0x616104 + (head->id * 0x800));
+		nvkm_wr32(device, 0x610194 + (head->id * 0x10), tmp);
+		tmp = nvkm_rd32(device, 0x616108 + (head->id * 0x800));
+		nvkm_wr32(device, 0x610198 + (head->id * 0x10), tmp);
+		tmp = nvkm_rd32(device, 0x61610c + (head->id * 0x800));
+		nvkm_wr32(device, 0x61019c + (head->id * 0x10), tmp);
 	}
 
 	/* ... DAC caps */