drm/nouveau/mmu: define user interfaces to mmu vmm opertaions

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

drivers/gpu/drm/nouveau/include/nvif/if000c.h

 #ifndef __NVIF_IF000C_H__
 #define __NVIF_IF000C_H__
+struct nvif_vmm_v0 {
+	__u8  version;
+	__u8  page_nr;
+	__u8  pad02[6];
+	__u64 addr;
+	__u64 size;
+	__u8  data[];
+};
+
+#define NVIF_VMM_V0_PAGE                                                   0x00
+#define NVIF_VMM_V0_GET                                                    0x01
+#define NVIF_VMM_V0_PUT                                                    0x02
+#define NVIF_VMM_V0_MAP                                                    0x03
+#define NVIF_VMM_V0_UNMAP                                                  0x04
+
+struct nvif_vmm_page_v0 {
+	__u8  version;
+	__u8  index;
+	__u8  shift;
+	__u8  sparse;
+	__u8  vram;
+	__u8  host;
+	__u8  comp;
+	__u8  pad07[1];
+};
+
+struct nvif_vmm_get_v0 {
+	__u8  version;
+#define NVIF_VMM_GET_V0_ADDR                                               0x00
+#define NVIF_VMM_GET_V0_PTES                                               0x01
+#define NVIF_VMM_GET_V0_LAZY	                                           0x02
+	__u8  type;
+	__u8  sparse;
+	__u8  page;
+	__u8  align;
+	__u8  pad05[3];
+	__u64 size;
+	__u64 addr;
+};
+
+struct nvif_vmm_put_v0 {
+	__u8  version;
+	__u8  pad01[7];
+	__u64 addr;
+};
+
+struct nvif_vmm_map_v0 {
+	__u8  version;
+	__u8  pad01[7];
+	__u64 addr;
+	__u64 size;
+	__u64 memory;
+	__u64 offset;
+	__u8  data[];
+};
+
+struct nvif_vmm_unmap_v0 {
+	__u8  version;
+	__u8  pad01[7];
+	__u64 addr;
+};
 #endif

drivers/gpu/drm/nouveau/include/nvif/vmm.h

+#ifndef __NVIF_VMM_H__
+#define __NVIF_VMM_H__
+#include <nvif/object.h>
+struct nvif_mem;
+struct nvif_mmu;
+
+enum nvif_vmm_get {
+	ADDR,
+	PTES,
+	LAZY
+};
+
+struct nvif_vma {
+	u64 addr;
+	u64 size;
+};
+
+struct nvif_vmm {
+	struct nvif_object object;
+	u64 start;
+	u64 limit;
+
+	struct {
+		u8 shift;
+		bool sparse:1;
+		bool vram:1;
+		bool host:1;
+		bool comp:1;
+	} *page;
+	int page_nr;
+};
+
+int nvif_vmm_init(struct nvif_mmu *, s32 oclass, u64 addr, u64 size,
+		  void *argv, u32 argc, struct nvif_vmm *);
+void nvif_vmm_fini(struct nvif_vmm *);
+int nvif_vmm_get(struct nvif_vmm *, enum nvif_vmm_get, bool sparse,
+		 u8 page, u8 align, u64 size, struct nvif_vma *);
+void nvif_vmm_put(struct nvif_vmm *, struct nvif_vma *);
+int nvif_vmm_map(struct nvif_vmm *, u64 addr, u64 size, void *argv, u32 argc,
+		 struct nvif_mem *, u64 offset);
+int nvif_vmm_unmap(struct nvif_vmm *, u64);
+#endif

drivers/gpu/drm/nouveau/nvif/Kbuild

@@ -5,3 +5,4 @@ nvif-y += nvif/driver.o
 nvif-y += nvif/mem.o
 nvif-y += nvif/mmu.o
 nvif-y += nvif/notify.o
+nvif-y += nvif/vmm.o

drivers/gpu/drm/nouveau/nvif/vmm.c

+/*
+ * 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.
+ */
+#include <nvif/vmm.h>
+#include <nvif/mem.h>
+
+#include <nvif/if000c.h>
+
+int
+nvif_vmm_unmap(struct nvif_vmm *vmm, u64 addr)
+{
+	return nvif_object_mthd(&vmm->object, NVIF_VMM_V0_UNMAP,
+				&(struct nvif_vmm_unmap_v0) { .addr = addr },
+				sizeof(struct nvif_vmm_unmap_v0));
+}
+
+int
+nvif_vmm_map(struct nvif_vmm *vmm, u64 addr, u64 size, void *argv, u32 argc,
+	     struct nvif_mem *mem, u64 offset)
+{
+	struct nvif_vmm_map_v0 *args;
+	u8 stack[16];
+	int ret;
+
+	if (sizeof(*args) + argc > sizeof(stack)) {
+		if (!(args = kmalloc(sizeof(*args) + argc, GFP_KERNEL)))
+			return -ENOMEM;
+	} else {
+		args = (void *)stack;
+	}
+
+	args->version = 0;
+	args->addr = addr;
+	args->size = size;
+	args->memory = nvif_handle(&mem->object);
+	args->offset = offset;
+	memcpy(args->data, argv, argc);
+
+	ret = nvif_object_mthd(&vmm->object, NVIF_VMM_V0_MAP,
+			       args, sizeof(*args) + argc);
+	if (args != (void *)stack)
+		kfree(args);
+	return ret;
+}
+
+void
+nvif_vmm_put(struct nvif_vmm *vmm, struct nvif_vma *vma)
+{
+	if (vma->size) {
+		WARN_ON(nvif_object_mthd(&vmm->object, NVIF_VMM_V0_PUT,
+					 &(struct nvif_vmm_put_v0) {
+						.addr = vma->addr,
+					 }, sizeof(struct nvif_vmm_put_v0)));
+		vma->size = 0;
+	}
+}
+
+int
+nvif_vmm_get(struct nvif_vmm *vmm, enum nvif_vmm_get type, bool sparse,
+	     u8 page, u8 align, u64 size, struct nvif_vma *vma)
+{
+	struct nvif_vmm_get_v0 args;
+	int ret;
+
+	args.version = vma->size = 0;
+	args.sparse = sparse;
+	args.page = page;
+	args.align = align;
+	args.size = size;
+
+	switch (type) {
+	case ADDR: args.type = NVIF_VMM_GET_V0_ADDR; break;
+	case PTES: args.type = NVIF_VMM_GET_V0_PTES; break;
+	case LAZY: args.type = NVIF_VMM_GET_V0_LAZY; break;
+	default:
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	ret = nvif_object_mthd(&vmm->object, NVIF_VMM_V0_GET,
+			       &args, sizeof(args));
+	if (ret == 0) {
+		vma->addr = args.addr;
+		vma->size = args.size;
+	}
+	return ret;
+}
+
+void
+nvif_vmm_fini(struct nvif_vmm *vmm)
+{
+	kfree(vmm->page);
+	nvif_object_fini(&vmm->object);
+}
+
+int
+nvif_vmm_init(struct nvif_mmu *mmu, s32 oclass, u64 addr, u64 size,
+	      void *argv, u32 argc, struct nvif_vmm *vmm)
+{
+	struct nvif_vmm_v0 *args;
+	u32 argn = sizeof(*args) + argc;
+	int ret = -ENOSYS, i;
+
+	vmm->object.client = NULL;
+	vmm->page = NULL;
+
+	if (!(args = kmalloc(argn, GFP_KERNEL)))
+		return -ENOMEM;
+	args->version = 0;
+	args->addr = addr;
+	args->size = size;
+	memcpy(args->data, argv, argc);
+
+	ret = nvif_object_init(&mmu->object, 0, oclass, args, argn,
+			       &vmm->object);
+	if (ret)
+		goto done;
+
+	vmm->start = args->addr;
+	vmm->limit = args->size;
+
+	vmm->page_nr = args->page_nr;
+	vmm->page = kmalloc(sizeof(*vmm->page) * vmm->page_nr, GFP_KERNEL);
+	if (!vmm->page) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	for (i = 0; i < vmm->page_nr; i++) {
+		struct nvif_vmm_page_v0 args = { .index = i };
+
+		ret = nvif_object_mthd(&vmm->object, NVIF_VMM_V0_PAGE,
+				       &args, sizeof(args));
+		if (ret)
+			break;
+
+		vmm->page[i].shift = args.shift;
+		vmm->page[i].sparse = args.sparse;
+		vmm->page[i].vram = args.vram;
+		vmm->page[i].host = args.host;
+		vmm->page[i].comp = args.comp;
+	}
+
+done:
+	if (ret)
+		nvif_vmm_fini(vmm);
+	kfree(args);
+	return ret;
+}

drivers/gpu/drm/nouveau/nvkm/subdev/mmu/Kbuild

@@ -32,3 +32,4 @@ nvkm-y += nvkm/subdev/mmu/vmmgp10b.o
 
 nvkm-y += nvkm/subdev/mmu/umem.o
 nvkm-y += nvkm/subdev/mmu/ummu.o
+nvkm-y += nvkm/subdev/mmu/uvmm.o

drivers/gpu/drm/nouveau/nvkm/subdev/mmu/ummu.c

@@ -21,6 +21,7 @@
  */
 #include "ummu.h"
 #include "umem.h"
+#include "uvmm.h"
 
 #include <core/client.h>
 
@@ -41,6 +42,14 @@ nvkm_ummu_sclass(struct nvkm_object *object, int index,
 		}
 	}
 
+	if (mmu->func->vmm.user.oclass) {
+		if (index-- == 0) {
+			oclass->base = mmu->func->vmm.user;
+			oclass->ctor = nvkm_uvmm_new;
+			return 0;
+		}
+	}
+
 	return -EINVAL;
 }
 

drivers/gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.c

+/*
+ * 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.
+ */
+#include "uvmm.h"
+#include "umem.h"
+#include "ummu.h"
+
+#include <core/client.h>
+#include <core/memory.h>
+
+#include <nvif/if000c.h>
+#include <nvif/unpack.h>
+
+static const struct nvkm_object_func nvkm_uvmm;
+struct nvkm_vmm *
+nvkm_uvmm_search(struct nvkm_client *client, u64 handle)
+{
+	struct nvkm_object *object;
+
+	object = nvkm_object_search(client, handle, &nvkm_uvmm);
+	if (IS_ERR(object))
+		return (void *)object;
+
+	return nvkm_uvmm(object)->vmm;
+}
+
+static int
+nvkm_uvmm_mthd_unmap(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
+{
+	struct nvkm_client *client = uvmm->object.client;
+	union {
+		struct nvif_vmm_unmap_v0 v0;
+	} *args = argv;
+	struct nvkm_vmm *vmm = uvmm->vmm;
+	struct nvkm_vma *vma;
+	int ret = -ENOSYS;
+	u64 addr;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, false))) {
+		addr = args->v0.addr;
+	} else
+		return ret;
+
+	mutex_lock(&vmm->mutex);
+	vma = nvkm_vmm_node_search(vmm, addr);
+	if (ret = -ENOENT, !vma || vma->addr != addr) {
+		VMM_DEBUG(vmm, "lookup %016llx: %016llx",
+			  addr, vma ? vma->addr : ~0ULL);
+		goto done;
+	}
+
+	if (ret = -ENOENT, (!vma->user && !client->super) || vma->busy) {
+		VMM_DEBUG(vmm, "denied %016llx: %d %d %d", addr,
+			  vma->user, !client->super, vma->busy);
+		goto done;
+	}
+
+	if (ret = -EINVAL, !vma->memory) {
+		VMM_DEBUG(vmm, "unmapped");
+		goto done;
+	}
+
+	nvkm_vmm_unmap_locked(vmm, vma);
+	ret = 0;
+done:
+	mutex_unlock(&vmm->mutex);
+	return ret;
+}
+
+static int
+nvkm_uvmm_mthd_map(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
+{
+	struct nvkm_client *client = uvmm->object.client;
+	union {
+		struct nvif_vmm_map_v0 v0;
+	} *args = argv;
+	u64 addr, size, handle, offset;
+	struct nvkm_vmm *vmm = uvmm->vmm;
+	struct nvkm_vma *vma;
+	struct nvkm_memory *memory;
+	int ret = -ENOSYS;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, true))) {
+		addr = args->v0.addr;
+		size = args->v0.size;
+		handle = args->v0.memory;
+		offset = args->v0.offset;
+	} else
+		return ret;
+
+	if (IS_ERR((memory = nvkm_umem_search(client, handle)))) {
+		VMM_DEBUG(vmm, "memory %016llx %ld\n", handle, PTR_ERR(memory));
+		return PTR_ERR(memory);
+	}
+
+	mutex_lock(&vmm->mutex);
+	if (ret = -ENOENT, !(vma = nvkm_vmm_node_search(vmm, addr))) {
+		VMM_DEBUG(vmm, "lookup %016llx", addr);
+		goto fail;
+	}
+
+	if (ret = -ENOENT, (!vma->user && !client->super) || vma->busy) {
+		VMM_DEBUG(vmm, "denied %016llx: %d %d %d", addr,
+			  vma->user, !client->super, vma->busy);
+		goto fail;
+	}
+
+	if (ret = -EINVAL, vma->addr != addr || vma->size != size) {
+		if (addr + size > vma->addr + vma->size || vma->memory ||
+		    (vma->refd == NVKM_VMA_PAGE_NONE && !vma->mapref)) {
+			VMM_DEBUG(vmm, "split %d %d %d "
+				       "%016llx %016llx %016llx %016llx",
+				  !!vma->memory, vma->refd, vma->mapref,
+				  addr, size, vma->addr, (u64)vma->size);
+			goto fail;
+		}
+
+		if (vma->addr != addr) {
+			const u64 tail = vma->size + vma->addr - addr;
+			if (ret = -ENOMEM, !(vma = nvkm_vma_tail(vma, tail)))
+				goto fail;
+			vma->part = true;
+			nvkm_vmm_node_insert(vmm, vma);
+		}
+
+		if (vma->size != size) {
+			const u64 tail = vma->size - size;
+			struct nvkm_vma *tmp;
+			if (ret = -ENOMEM, !(tmp = nvkm_vma_tail(vma, tail))) {
+				nvkm_vmm_unmap_region(vmm, vma);
+				goto fail;
+			}
+			tmp->part = true;
+			nvkm_vmm_node_insert(vmm, tmp);
+		}
+	}
+	vma->busy = true;
+	mutex_unlock(&vmm->mutex);
+
+	ret = nvkm_memory_map(memory, offset, vmm, vma, argv, argc);
+	if (ret == 0) {
+		/* Successful map will clear vma->busy. */
+		nvkm_memory_unref(&memory);
+		return 0;
+	}
+
+	mutex_lock(&vmm->mutex);
+	vma->busy = false;
+	nvkm_vmm_unmap_region(vmm, vma);
+fail:
+	mutex_unlock(&vmm->mutex);
+	nvkm_memory_unref(&memory);
+	return ret;
+}
+
+static int
+nvkm_uvmm_mthd_put(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
+{
+	struct nvkm_client *client = uvmm->object.client;
+	union {
+		struct nvif_vmm_put_v0 v0;
+	} *args = argv;
+	struct nvkm_vmm *vmm = uvmm->vmm;
+	struct nvkm_vma *vma;
+	int ret = -ENOSYS;
+	u64 addr;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, false))) {
+		addr = args->v0.addr;
+	} else
+		return ret;
+
+	mutex_lock(&vmm->mutex);
+	vma = nvkm_vmm_node_search(vmm, args->v0.addr);
+	if (ret = -ENOENT, !vma || vma->addr != addr || vma->part) {
+		VMM_DEBUG(vmm, "lookup %016llx: %016llx %d", addr,
+			  vma ? vma->addr : ~0ULL, vma ? vma->part : 0);
+		goto done;
+	}
+
+	if (ret = -ENOENT, (!vma->user && !client->super) || vma->busy) {
+		VMM_DEBUG(vmm, "denied %016llx: %d %d %d", addr,
+			  vma->user, !client->super, vma->busy);
+		goto done;
+	}
+
+	nvkm_vmm_put_locked(vmm, vma);
+	ret = 0;
+done:
+	mutex_unlock(&vmm->mutex);
+	return ret;
+}
+
+static int
+nvkm_uvmm_mthd_get(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
+{
+	struct nvkm_client *client = uvmm->object.client;
+	union {
+		struct nvif_vmm_get_v0 v0;
+	} *args = argv;
+	struct nvkm_vmm *vmm = uvmm->vmm;
+	struct nvkm_vma *vma;
+	int ret = -ENOSYS;
+	bool getref, mapref, sparse;
+	u8 page, align;
+	u64 size;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, false))) {
+		getref = args->v0.type == NVIF_VMM_GET_V0_PTES;
+		mapref = args->v0.type == NVIF_VMM_GET_V0_ADDR;
+		sparse = args->v0.sparse;
+		page = args->v0.page;
+		align = args->v0.align;
+		size = args->v0.size;
+	} else
+		return ret;
+
+	mutex_lock(&vmm->mutex);
+	ret = nvkm_vmm_get_locked(vmm, getref, mapref, sparse,
+				  page, align, size, &vma);
+	mutex_unlock(&vmm->mutex);
+	if (ret)
+		return ret;
+
+	args->v0.addr = vma->addr;
+	vma->user = !client->super;
+	return ret;
+}
+
+static int
+nvkm_uvmm_mthd_page(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
+{
+	union {
+		struct nvif_vmm_page_v0 v0;
+	} *args = argv;
+	const struct nvkm_vmm_page *page;
+	int ret = -ENOSYS;
+	u8 type, index, nr;
+
+	page = uvmm->vmm->func->page;
+	for (nr = 0; page[nr].shift; nr++);
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, false))) {
+		if ((index = args->v0.index) >= nr)
+			return -EINVAL;
+		type = page[index].type;
+		args->v0.shift = page[index].shift;
+		args->v0.sparse = !!(type & NVKM_VMM_PAGE_SPARSE);
+		args->v0.vram = !!(type & NVKM_VMM_PAGE_VRAM);
+		args->v0.host = !!(type & NVKM_VMM_PAGE_HOST);
+		args->v0.comp = !!(type & NVKM_VMM_PAGE_COMP);
+	} else
+		return -ENOSYS;
+
+	return 0;
+}
+
+static int
+nvkm_uvmm_mthd(struct nvkm_object *object, u32 mthd, void *argv, u32 argc)
+{
+	struct nvkm_uvmm *uvmm = nvkm_uvmm(object);
+	switch (mthd) {
+	case NVIF_VMM_V0_PAGE  : return nvkm_uvmm_mthd_page  (uvmm, argv, argc);
+	case NVIF_VMM_V0_GET   : return nvkm_uvmm_mthd_get   (uvmm, argv, argc);
+	case NVIF_VMM_V0_PUT   : return nvkm_uvmm_mthd_put   (uvmm, argv, argc);
+	case NVIF_VMM_V0_MAP   : return nvkm_uvmm_mthd_map   (uvmm, argv, argc);
+	case NVIF_VMM_V0_UNMAP : return nvkm_uvmm_mthd_unmap (uvmm, argv, argc);
+	default:
+		break;
+	}
+	return -EINVAL;
+}
+
+static void *
+nvkm_uvmm_dtor(struct nvkm_object *object)
+{
+	struct nvkm_uvmm *uvmm = nvkm_uvmm(object);
+	nvkm_vmm_unref(&uvmm->vmm);
+	return uvmm;
+}
+
+static const struct nvkm_object_func
+nvkm_uvmm = {
+	.dtor = nvkm_uvmm_dtor,
+	.mthd = nvkm_uvmm_mthd,
+};
+
+int
+nvkm_uvmm_new(const struct nvkm_oclass *oclass, void *argv, u32 argc,
+	      struct nvkm_object **pobject)
+{
+	struct nvkm_mmu *mmu = nvkm_ummu(oclass->parent)->mmu;
+	const bool more = oclass->base.maxver >= 0;
+	union {
+		struct nvif_vmm_v0 v0;
+	} *args = argv;
+	const struct nvkm_vmm_page *page;
+	struct nvkm_uvmm *uvmm;
+	int ret = -ENOSYS;
+	u64 addr, size;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, more))) {
+		addr = args->v0.addr;
+		size = args->v0.size;
+	} else
+		return ret;
+
+	if (!(uvmm = kzalloc(sizeof(*uvmm), GFP_KERNEL)))
+		return -ENOMEM;
+	nvkm_object_ctor(&nvkm_uvmm, oclass, &uvmm->object);
+	*pobject = &uvmm->object;
+
+	if (!mmu->vmm) {
+		ret = mmu->func->vmm.ctor(mmu, addr, size, argv, argc,
+					  NULL, "user", &uvmm->vmm);
+		if (ret)
+			return ret;
+
+		uvmm->vmm->debug = max(uvmm->vmm->debug, oclass->client->debug);
+	} else {
+		if (size)
+			return -EINVAL;
+
+		uvmm->vmm = nvkm_vmm_ref(mmu->vmm);
+	}
+
+	page = uvmm->vmm->func->page;
+	args->v0.page_nr = 0;
+	while (page && (page++)->shift)
+		args->v0.page_nr++;
+	args->v0.addr = uvmm->vmm->start;
+	args->v0.size = uvmm->vmm->limit;
+	return 0;
+}

drivers/gpu/drm/nouveau/nvkm/subdev/mmu/uvmm.h

+#ifndef __NVKM_UVMM_H__
+#define __NVKM_UVMM_H__
+#define nvkm_uvmm(p) container_of((p), struct nvkm_uvmm, object)
+#include <core/object.h>
+#include "vmm.h"
+
+struct nvkm_uvmm {
+	struct nvkm_object object;
+	struct nvkm_vmm *vmm;
+};
+
+int nvkm_uvmm_new(const struct nvkm_oclass *, void *argv, u32 argc,
+		  struct nvkm_object **);
+#endif