diff --git a/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h b/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h
index 2f2059c5d4c9eff84b44d3ec7c477b8276de64b3..b688121f1a91e16ace1eed96bb7437e16f527dfa 100644
--- a/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h
+++ b/drivers/gpu/drm/nouveau/include/nvkm/engine/fifo.h
@@ -37,6 +37,9 @@ struct nvkm_fifo {
 	const struct nvkm_fifo_func *func;
 	struct nvkm_engine engine;
 
+	struct nvkm_chid *chid;
+	struct nvkm_chid *cgid;
+
 	DECLARE_BITMAP(mask, NVKM_FIFO_CHID_NR);
 	int nr;
 	struct list_head chan;
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild
index 76d2bf1f6d8b4a858cf330525dd98dacf1951e0f..c985736bff2c4c65204408aefaa630eaa2331afb 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/Kbuild
@@ -1,5 +1,8 @@
 # SPDX-License-Identifier: MIT
 nvkm-y += nvkm/engine/fifo/base.o
+nvkm-y += nvkm/engine/fifo/chan.o
+nvkm-y += nvkm/engine/fifo/chid.o
+
 nvkm-y += nvkm/engine/fifo/nv04.o
 nvkm-y += nvkm/engine/fifo/nv10.o
 nvkm-y += nvkm/engine/fifo/nv17.o
@@ -18,7 +21,6 @@ nvkm-y += nvkm/engine/fifo/gv100.o
 nvkm-y += nvkm/engine/fifo/tu102.o
 nvkm-y += nvkm/engine/fifo/ga102.o
 
-nvkm-y += nvkm/engine/fifo/chan.o
 nvkm-y += nvkm/engine/fifo/channv50.o
 nvkm-y += nvkm/engine/fifo/chang84.o
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c
index 4e099bf0a3fa91ed15cff3b953906a26a056223a..e6b0653625f5a782e511350c7824e6fb8e7b668b 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/base.c
@@ -23,6 +23,7 @@
  */
 #include "priv.h"
 #include "chan.h"
+#include "chid.h"
 
 #include <core/gpuobj.h>
 #include <subdev/mc.h>
@@ -218,13 +219,15 @@ static int
 nvkm_fifo_info(struct nvkm_engine *engine, u64 mthd, u64 *data)
 {
 	struct nvkm_fifo *fifo = nvkm_fifo(engine);
+
 	switch (mthd) {
-	case NV_DEVICE_HOST_CHANNELS: *data = fifo->nr; return 0;
+	case NV_DEVICE_HOST_CHANNELS: *data = fifo->chid ? fifo->chid->nr : 0; return 0;
 	default:
 		if (fifo->func->info)
 			return fifo->func->info(fifo, mthd, data);
 		break;
 	}
+
 	return -ENOSYS;
 }
 
@@ -232,8 +235,18 @@ static int
 nvkm_fifo_oneinit(struct nvkm_engine *engine)
 {
 	struct nvkm_fifo *fifo = nvkm_fifo(engine);
+	int ret;
+
+	/* Initialise CHID/CGID allocator(s) on GPUs where they aren't per-runlist. */
+	if (fifo->func->chid_nr) {
+		ret = fifo->func->chid_ctor(fifo, fifo->func->chid_nr(fifo));
+		if (ret)
+			return ret;
+	}
+
 	if (fifo->func->oneinit)
 		return fifo->func->oneinit(fifo);
+
 	return 0;
 }
 
@@ -248,6 +261,10 @@ nvkm_fifo_dtor(struct nvkm_engine *engine)
 {
 	struct nvkm_fifo *fifo = nvkm_fifo(engine);
 	void *data = fifo;
+
+	nvkm_chid_unref(&fifo->cgid);
+	nvkm_chid_unref(&fifo->chid);
+
 	if (fifo->func->dtor)
 		data = fifo->func->dtor(fifo);
 	nvkm_event_fini(&fifo->kevent);
@@ -289,7 +306,6 @@ nvkm_fifo_ctor(const struct nvkm_fifo_func *func, struct nvkm_device *device,
 		fifo->nr = NVKM_FIFO_CHID_NR;
 	else
 		fifo->nr = nr;
-	bitmap_clear(fifo->mask, 0, fifo->nr);
 
 	if (func->uevent_init) {
 		ret = nvkm_event_init(&nvkm_fifo_uevent_func, &fifo->engine.subdev, 1, 1,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.c
index 4d4905be4b92b1aa47fa5e977a2d15e3c760805d..464c956aaca9dc13be628181855a9ac4038bbfe2 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.c
@@ -32,6 +32,10 @@
 
 #include <nvif/if0020.h>
 
+const struct nvkm_event_func
+nvkm_chan_event = {
+};
+
 struct nvkm_fifo_chan_object {
 	struct nvkm_oproxy oproxy;
 	struct nvkm_fifo_chan *chan;
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.h b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.h
index 24fbe6cf70e1b9f1d0a8580665344206d4c17e50..a9c0e02b6f9f421cb77b35fce6fd6dcb56dc5e4f 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chan.h
@@ -4,6 +4,8 @@
 #define nvkm_chan(p) container_of((p), struct nvkm_chan, object) /*FIXME: remove later */
 #include <engine/fifo.h>
 
+extern const struct nvkm_event_func nvkm_chan_event;
+
 struct nvkm_chan_func {
 	void *(*dtor)(struct nvkm_fifo_chan *);
 	void (*init)(struct nvkm_fifo_chan *);
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chid.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chid.c
new file mode 100644
index 0000000000000000000000000000000000000000..7c582bce7e24502a3274675729e266346a089546
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chid.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright 2020 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.
+ */
+#include "chid.h"
+
+static void
+nvkm_chid_del(struct kref *kref)
+{
+	struct nvkm_chid *chid = container_of(kref, typeof(*chid), kref);
+
+	nvkm_event_fini(&chid->event);
+
+	kvfree(chid->data);
+	kfree(chid);
+}
+
+void
+nvkm_chid_unref(struct nvkm_chid **pchid)
+{
+	struct nvkm_chid *chid = *pchid;
+
+	if (!chid)
+		return;
+
+	kref_put(&chid->kref, nvkm_chid_del);
+	*pchid = NULL;
+}
+
+struct nvkm_chid *
+nvkm_chid_ref(struct nvkm_chid *chid)
+{
+	if (chid)
+		kref_get(&chid->kref);
+
+	return chid;
+}
+
+int
+nvkm_chid_new(const struct nvkm_event_func *func, struct nvkm_subdev *subdev,
+	      int nr, int first, int count, struct nvkm_chid **pchid)
+{
+	struct nvkm_chid *chid;
+	int id;
+
+	if (!(chid = *pchid = kzalloc(struct_size(chid, used, nr), GFP_KERNEL)))
+		return -ENOMEM;
+
+	kref_init(&chid->kref);
+	chid->nr = nr;
+	chid->mask = chid->nr - 1;
+	spin_lock_init(&chid->lock);
+
+	if (!(chid->data = kvzalloc(sizeof(*chid->data) * nr, GFP_KERNEL))) {
+		nvkm_chid_unref(pchid);
+		return -ENOMEM;
+	}
+
+	for (id = 0; id < first; id++)
+		__set_bit(id, chid->used);
+	for (id = first + count; id < nr; id++)
+		__set_bit(id, chid->used);
+
+	return nvkm_event_init(func, subdev, 1, nr, &chid->event);
+}
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chid.h b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chid.h
new file mode 100644
index 0000000000000000000000000000000000000000..d359828dde8099ad356f70398995b087a1187022
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/chid.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: MIT */
+#ifndef __NVKM_CHID_H__
+#define __NVKM_CHID_H__
+#include <core/event.h>
+
+struct nvkm_chid {
+	struct kref kref;
+	int nr;
+	u32 mask;
+
+	struct nvkm_event event;
+
+	void **data;
+
+	spinlock_t lock;
+	unsigned long used[];
+};
+
+int nvkm_chid_new(const struct nvkm_event_func *, struct nvkm_subdev *,
+		  int nr, int first, int count, struct nvkm_chid **pchid);
+struct nvkm_chid *nvkm_chid_ref(struct nvkm_chid *);
+void nvkm_chid_unref(struct nvkm_chid **);
+#endif
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/g84.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/g84.c
index 24732d355c8315f6ebf8db761021c5b9d5b3e3fd..dbb9df6f8eb51273cdcdb8a661ddab4b5339fb06 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/g84.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/g84.c
@@ -119,6 +119,7 @@ g84_fifo = {
 	.dtor = nv50_fifo_dtor,
 	.oneinit = nv50_fifo_oneinit,
 	.chid_nr = nv50_fifo_chid_nr,
+	.chid_ctor = nv50_fifo_chid_ctor,
 	.init = nv50_fifo_init,
 	.intr = nv04_fifo_intr,
 	.engine_id = g84_fifo_engine_id,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c
index 1a641b1fdfbf1c110a4e4129657ec6e4494b01d7..d8eeca81863728ba4b6a3e595c91a85bc817ab6e 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gf100.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "chan.h"
+#include "chid.h"
 
 #include "gf100.h"
 #include "changf100.h"
@@ -624,6 +625,12 @@ gf100_fifo_init(struct nvkm_fifo *base)
 	nvkm_wr32(device, 0x002628, 0x00000001); /* ENGINE_INTR_EN */
 }
 
+int
+gf100_fifo_chid_ctor(struct nvkm_fifo *fifo, int nr)
+{
+	return nvkm_chid_new(&nvkm_chan_event, &fifo->engine.subdev, nr, 0, nr, &fifo->chid);
+}
+
 static int
 gf100_fifo_oneinit(struct nvkm_fifo *base)
 {
@@ -681,6 +688,7 @@ gf100_fifo = {
 	.dtor = gf100_fifo_dtor,
 	.oneinit = gf100_fifo_oneinit,
 	.chid_nr = nv50_fifo_chid_nr,
+	.chid_ctor = gf100_fifo_chid_ctor,
 	.init = gf100_fifo_init,
 	.fini = gf100_fifo_fini,
 	.intr = gf100_fifo_intr,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
index 880ddfec22f7ae765cfbe3d2573a2f91472a87fa..c4fa4fc68d467f5ab8502eab131455d9491e1804 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "chan.h"
+#include "chid.h"
 
 #include "gk104.h"
 #include "cgrp.h"
@@ -1193,6 +1194,7 @@ gk104_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gk104_fifo_chid_nr,
+	.chid_ctor = gf100_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.h b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.h
index 962187740010655c0ee08f0c774b6a000e356a8c..af6a004a62670587f53dca4632888335ac82344a 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk104.h
@@ -74,7 +74,7 @@ void gk104_fifo_intr_pbdma_1(struct gk104_fifo *fifo, int unit);
 void gk104_fifo_intr_runlist(struct gk104_fifo *fifo);
 void gk104_fifo_intr_engine(struct gk104_fifo *fifo);
 void *gk104_fifo_dtor(struct nvkm_fifo *base);
-int gk104_fifo_oneinit(struct nvkm_fifo *base);
+int gk104_fifo_oneinit(struct nvkm_fifo *);
 int gk104_fifo_info(struct nvkm_fifo *base, u64 mthd, u64 *data);
 void gk104_fifo_init(struct nvkm_fifo *base);
 void gk104_fifo_fini(struct nvkm_fifo *base);
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk110.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk110.c
index 9dcc54f1d016b325a90ab3af536a9ab5d308231c..b23d50d1b351f971e652adf745f0e0f0487ef6e7 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk110.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk110.c
@@ -23,6 +23,7 @@
  */
 #include "cgrp.h"
 #include "chan.h"
+#include "chid.h"
 
 #include "gk104.h"
 #include "changk104.h"
@@ -56,11 +57,24 @@ gk110_fifo_runlist = {
 	.commit = gk104_fifo_runlist_commit,
 };
 
+int
+gk110_fifo_chid_ctor(struct nvkm_fifo *fifo, int nr)
+{
+	int ret;
+
+	ret = nvkm_chid_new(&nvkm_chan_event, &fifo->engine.subdev, nr, 0, nr, &fifo->cgid);
+	if (ret)
+		return ret;
+
+	return gf100_fifo_chid_ctor(fifo, nr);
+}
+
 static const struct nvkm_fifo_func
 gk110_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gk104_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk208.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk208.c
index 28791baf77f8ae29d0e70eb455efbfd8b7f72be0..1dd937bdbbae04d6c5b383cbd37e6a42db91c0e0 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk208.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk208.c
@@ -54,6 +54,7 @@ gk208_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gk208_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk20a.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk20a.c
index b62e3bb0294cad96a39250049b6434eefeb1fd65..d2e78d2a868a581dfbd88e959441c9ca624b4c91 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk20a.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gk20a.c
@@ -29,6 +29,7 @@ gk20a_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = nv50_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c
index f996f1c1141a02c2671110b8e105f897d5de90fb..32ef88a90d1e8c0698bed497ee66eb4dda6263ba 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm107.c
@@ -114,6 +114,7 @@ gm107_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gm107_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm200.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm200.c
index 8f3da21ce1e763db0c60f8191e1f1db528a829f1..74891833926e0a6c5d0c46ebb5a79712dcf9a9b7 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm200.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gm200.c
@@ -51,6 +51,7 @@ gm200_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gm200_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c
index dc590848c25c7eac69687f3bc015db9f694d5cff..c1ad59d1223b3111dd191fb3743404b388881492 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gp100.c
@@ -86,6 +86,7 @@ gp100_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gm200_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gv100.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gv100.c
index 36c02b5aac0f96dd12a4755a11f1614664c9ae48..9e876bd871bb4cc0bcb0b6f5762e5a0064f94c0a 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gv100.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/gv100.c
@@ -301,6 +301,7 @@ gv100_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gm200_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c
index f9f8371d375656a5e8a817e414e5d6e47e25e512..18fa5b933e9ef871d2113bdfbfe46016cd9ae4a4 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.c
@@ -23,6 +23,7 @@
  */
 #include "cgrp.h"
 #include "chan.h"
+#include "chid.h"
 
 #include "nv04.h"
 #include "channv04.h"
@@ -58,7 +59,6 @@ nv04_fifo_dma_fini(struct nvkm_fifo_chan *base)
 	struct nvkm_memory *fctx = device->imem->ramfc;
 	const struct nv04_fifo_ramfc *c;
 	unsigned long flags;
-	u32 mask = fifo->base.nr - 1;
 	u32 data = chan->ramfc;
 	u32 chid;
 
@@ -67,7 +67,7 @@ nv04_fifo_dma_fini(struct nvkm_fifo_chan *base)
 	nvkm_wr32(device, NV03_PFIFO_CACHES, 0);
 
 	/* if this channel is active, replace it with a null context */
-	chid = nvkm_rd32(device, NV03_PFIFO_CACHE1_PUSH1) & mask;
+	chid = nvkm_rd32(device, NV03_PFIFO_CACHE1_PUSH1) & fifo->base.chid->mask;
 	if (chid == chan->base.chid) {
 		nvkm_mask(device, NV04_PFIFO_CACHE1_DMA_PUSH, 0x00000001, 0);
 		nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH0, 0);
@@ -91,7 +91,7 @@ nv04_fifo_dma_fini(struct nvkm_fifo_chan *base)
 
 		nvkm_wr32(device, NV03_PFIFO_CACHE1_GET, 0);
 		nvkm_wr32(device, NV03_PFIFO_CACHE1_PUT, 0);
-		nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, mask);
+		nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, fifo->base.chid->mask);
 		nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH0, 1);
 		nvkm_wr32(device, NV04_PFIFO_CACHE1_PULL0, 1);
 	}
@@ -360,7 +360,7 @@ nv04_fifo_intr(struct nvkm_fifo *base)
 	reassign = nvkm_rd32(device, NV03_PFIFO_CACHES) & 1;
 	nvkm_wr32(device, NV03_PFIFO_CACHES, 0);
 
-	chid = nvkm_rd32(device, NV03_PFIFO_CACHE1_PUSH1) & (fifo->base.nr - 1);
+	chid = nvkm_rd32(device, NV03_PFIFO_CACHE1_PUSH1) & fifo->base.chid->mask;
 	get  = nvkm_rd32(device, NV03_PFIFO_CACHE1_GET);
 
 	if (stat & NV_PFIFO_INTR_CACHE_ERROR) {
@@ -407,10 +407,9 @@ nv04_fifo_intr(struct nvkm_fifo *base)
 }
 
 void
-nv04_fifo_init(struct nvkm_fifo *base)
+nv04_fifo_init(struct nvkm_fifo *fifo)
 {
-	struct nv04_fifo *fifo = nv04_fifo(base);
-	struct nvkm_device *device = fifo->base.engine.subdev.device;
+	struct nvkm_device *device = fifo->engine.subdev.device;
 	struct nvkm_instmem *imem = device->imem;
 	struct nvkm_ramht *ramht = imem->ramht;
 	struct nvkm_memory *ramro = imem->ramro;
@@ -425,7 +424,7 @@ nv04_fifo_init(struct nvkm_fifo *base)
 	nvkm_wr32(device, NV03_PFIFO_RAMRO, nvkm_memory_addr(ramro) >> 8);
 	nvkm_wr32(device, NV03_PFIFO_RAMFC, nvkm_memory_addr(ramfc) >> 8);
 
-	nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, fifo->base.nr - 1);
+	nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, fifo->chid->mask);
 
 	nvkm_wr32(device, NV03_PFIFO_INTR_0, 0xffffffff);
 	nvkm_wr32(device, NV03_PFIFO_INTR_EN_0, 0xffffffff);
@@ -435,6 +434,13 @@ nv04_fifo_init(struct nvkm_fifo *base)
 	nvkm_wr32(device, NV03_PFIFO_CACHES, 1);
 }
 
+int
+nv04_fifo_chid_ctor(struct nvkm_fifo *fifo, int nr)
+{
+	/* The last CHID is reserved by HW as a "channel invalid" marker. */
+	return nvkm_chid_new(&nvkm_chan_event, &fifo->engine.subdev, nr, 0, nr - 1, &fifo->chid);
+}
+
 static int
 nv04_fifo_chid_nr(struct nvkm_fifo *fifo)
 {
@@ -465,6 +471,7 @@ nv04_fifo_new_(const struct nvkm_fifo_func *func, struct nvkm_device *device,
 static const struct nvkm_fifo_func
 nv04_fifo = {
 	.chid_nr = nv04_fifo_chid_nr,
+	.chid_ctor = nv04_fifo_chid_ctor,
 	.init = nv04_fifo_init,
 	.intr = nv04_fifo_intr,
 	.engine_id = nv04_fifo_engine_id,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.h b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.h
index 3f23bcde4a540cc3c9a4384744f675120d08a023..879c686675d66ffe5eb08e6bd7998cfc76d2d900 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv04.h
@@ -19,5 +19,4 @@ struct nv04_fifo {
 
 int nv04_fifo_new_(const struct nvkm_fifo_func *, struct nvkm_device *, enum nvkm_subdev_type, int,
 		   int nr, const struct nv04_fifo_ramfc *, struct nvkm_fifo **);
-void nv04_fifo_init(struct nvkm_fifo *);
 #endif
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv10.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv10.c
index f07304e4b8c50e0d9585b238d2bbafab860a0b22..bc25520cb39b4660e44dd9c44ec66e0d4ba0faf2 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv10.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv10.c
@@ -56,6 +56,7 @@ nv10_fifo_chid_nr(struct nvkm_fifo *fifo)
 static const struct nvkm_fifo_func
 nv10_fifo = {
 	.chid_nr = nv10_fifo_chid_nr,
+	.chid_ctor = nv04_fifo_chid_ctor,
 	.init = nv04_fifo_init,
 	.intr = nv04_fifo_intr,
 	.engine_id = nv04_fifo_engine_id,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv17.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv17.c
index 858c8ba158c94e0d50b602d79eac44e47b9fa8af..dd254d88d008fbb7c2390c556f6b213f492e4255 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv17.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv17.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "chan.h"
+#include "chid.h"
 
 #include "nv04.h"
 #include "channv04.h"
@@ -56,10 +57,9 @@ nv17_chan = {
 };
 
 static void
-nv17_fifo_init(struct nvkm_fifo *base)
+nv17_fifo_init(struct nvkm_fifo *fifo)
 {
-	struct nv04_fifo *fifo = nv04_fifo(base);
-	struct nvkm_device *device = fifo->base.engine.subdev.device;
+	struct nvkm_device *device = fifo->engine.subdev.device;
 	struct nvkm_instmem *imem = device->imem;
 	struct nvkm_ramht *ramht = imem->ramht;
 	struct nvkm_memory *ramro = imem->ramro;
@@ -75,7 +75,7 @@ nv17_fifo_init(struct nvkm_fifo *base)
 	nvkm_wr32(device, NV03_PFIFO_RAMFC, nvkm_memory_addr(ramfc) >> 8 |
 					    0x00010000);
 
-	nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, fifo->base.nr - 1);
+	nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, fifo->chid->mask);
 
 	nvkm_wr32(device, NV03_PFIFO_INTR_0, 0xffffffff);
 	nvkm_wr32(device, NV03_PFIFO_INTR_EN_0, 0xffffffff);
@@ -88,6 +88,7 @@ nv17_fifo_init(struct nvkm_fifo *base)
 static const struct nvkm_fifo_func
 nv17_fifo = {
 	.chid_nr = nv10_fifo_chid_nr,
+	.chid_ctor = nv04_fifo_chid_ctor,
 	.init = nv17_fifo_init,
 	.intr = nv04_fifo_intr,
 	.engine_id = nv04_fifo_engine_id,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv40.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv40.c
index 30f924e3da3c87a7d9a6e3a8cf0881d4fd078a36..c87d995e4fd1eb4dc6b303209e4b9b00495839f6 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv40.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv40.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "chan.h"
+#include "chid.h"
 
 #include "nv04.h"
 #include "channv04.h"
@@ -65,10 +66,9 @@ nv40_chan = {
 };
 
 static void
-nv40_fifo_init(struct nvkm_fifo *base)
+nv40_fifo_init(struct nvkm_fifo *fifo)
 {
-	struct nv04_fifo *fifo = nv04_fifo(base);
-	struct nvkm_device *device = fifo->base.engine.subdev.device;
+	struct nvkm_device *device = fifo->engine.subdev.device;
 	struct nvkm_fb *fb = device->fb;
 	struct nvkm_instmem *imem = device->imem;
 	struct nvkm_ramht *ramht = imem->ramht;
@@ -106,7 +106,7 @@ nv40_fifo_init(struct nvkm_fifo *base)
 		break;
 	}
 
-	nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, fifo->base.nr - 1);
+	nvkm_wr32(device, NV03_PFIFO_CACHE1_PUSH1, fifo->chid->mask);
 
 	nvkm_wr32(device, NV03_PFIFO_INTR_0, 0xffffffff);
 	nvkm_wr32(device, NV03_PFIFO_INTR_EN_0, 0xffffffff);
@@ -119,6 +119,7 @@ nv40_fifo_init(struct nvkm_fifo *base)
 static const struct nvkm_fifo_func
 nv40_fifo = {
 	.chid_nr = nv10_fifo_chid_nr,
+	.chid_ctor = nv04_fifo_chid_ctor,
 	.init = nv40_fifo_init,
 	.intr = nv04_fifo_intr,
 	.engine_id = nv04_fifo_engine_id,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv50.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv50.c
index 101015a1a7e94a1844b0dac44940c706c6aefb1e..13c514acc9d72cf1212a71d7c71fe87a993f0a76 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv50.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/nv50.c
@@ -22,6 +22,7 @@
  * Authors: Ben Skeggs
  */
 #include "chan.h"
+#include "chid.h"
 
 #include "nv50.h"
 #include "channv50.h"
@@ -88,6 +89,13 @@ nv50_fifo_init(struct nvkm_fifo *base)
 	nvkm_wr32(device, 0x002500, 0x00000001);
 }
 
+int
+nv50_fifo_chid_ctor(struct nvkm_fifo *fifo, int nr)
+{
+	/* CHID 0 is unusable (some kind of PIO channel?), 127 is "channel invalid". */
+	return nvkm_chid_new(&nvkm_chan_event, &fifo->engine.subdev, nr, 1, nr - 2, &fifo->chid);
+}
+
 int
 nv50_fifo_chid_nr(struct nvkm_fifo *fifo)
 {
@@ -144,6 +152,7 @@ nv50_fifo = {
 	.dtor = nv50_fifo_dtor,
 	.oneinit = nv50_fifo_oneinit,
 	.chid_nr = nv50_fifo_chid_nr,
+	.chid_ctor = nv50_fifo_chid_ctor,
 	.init = nv50_fifo_init,
 	.intr = nv04_fifo_intr,
 	.engine_id = nv04_fifo_engine_id,
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h
index ba3dbc86435e4b2f9d2da5f0595f9c03d832743c..80280841cf814c9fe2531db1e236c07756851edd 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/priv.h
@@ -21,6 +21,7 @@ struct nvkm_fifo_func {
 
 	int (*oneinit)(struct nvkm_fifo *);
 	int (*chid_nr)(struct nvkm_fifo *);
+	int (*chid_ctor)(struct nvkm_fifo *, int nr);
 
 	int (*info)(struct nvkm_fifo *, u64 mthd, u64 *data);
 	void (*init)(struct nvkm_fifo *);
@@ -86,6 +87,8 @@ struct nvkm_fifo_func {
 int nvkm_fifo_ctor(const struct nvkm_fifo_func *, struct nvkm_device *, enum nvkm_subdev_type, int,
 		   struct nvkm_fifo *);
 
+int nv04_fifo_chid_ctor(struct nvkm_fifo *, int);
+void nv04_fifo_init(struct nvkm_fifo *);
 void nv04_fifo_intr(struct nvkm_fifo *);
 int nv04_fifo_engine_id(struct nvkm_fifo *, struct nvkm_engine *);
 struct nvkm_engine *nv04_fifo_id_engine(struct nvkm_fifo *, int);
@@ -96,9 +99,11 @@ extern const struct nvkm_cgrp_func nv04_cgrp;
 int nv10_fifo_chid_nr(struct nvkm_fifo *);
 
 int nv50_fifo_chid_nr(struct nvkm_fifo *);
+int nv50_fifo_chid_ctor(struct nvkm_fifo *, int);
 
 extern const struct nvkm_chan_func g84_chan;
 
+int gf100_fifo_chid_ctor(struct nvkm_fifo *, int);
 void gf100_fifo_intr_mmu_fault_unit(struct nvkm_fifo *, int);
 
 int gk104_fifo_chid_nr(struct nvkm_fifo *);
@@ -109,6 +114,7 @@ void gk104_fifo_recover_chan(struct nvkm_fifo *, int);
 int gk104_fifo_engine_id(struct nvkm_fifo *, struct nvkm_engine *);
 struct nvkm_engine *gk104_fifo_id_engine(struct nvkm_fifo *, int);
 
+int gk110_fifo_chid_ctor(struct nvkm_fifo *, int);
 extern const struct nvkm_cgrp_func gk110_cgrp;
 extern const struct nvkm_chan_func gk110_chan;
 
diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/tu102.c b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/tu102.c
index 274096316a1b12cb2a1ed0b2111e2a028e4d65ac..fbc67b84a8b10cf7f2a2ef0c10a949d093cd710b 100644
--- a/drivers/gpu/drm/nouveau/nvkm/engine/fifo/tu102.c
+++ b/drivers/gpu/drm/nouveau/nvkm/engine/fifo/tu102.c
@@ -442,6 +442,7 @@ tu102_fifo = {
 	.dtor = gk104_fifo_dtor,
 	.oneinit = gk104_fifo_oneinit,
 	.chid_nr = gm200_fifo_chid_nr,
+	.chid_ctor = gk110_fifo_chid_ctor,
 	.info = gk104_fifo_info,
 	.init = gk104_fifo_init,
 	.fini = gk104_fifo_fini,