drm/nouveau/mmu: add a privileged method to directly manage PTEs

This provides a somewhat more direct method of manipulating the GPU page
tables, which will be required to support SVM.

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

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

@@ -15,6 +15,8 @@ struct nvif_vmm_v0 {
 #define NVIF_VMM_V0_PUT                                                    0x02
 #define NVIF_VMM_V0_MAP                                                    0x03
 #define NVIF_VMM_V0_UNMAP                                                  0x04
+#define NVIF_VMM_V0_PFNMAP                                                 0x05
+#define NVIF_VMM_V0_PFNCLR                                                 0x06
 
 struct nvif_vmm_page_v0 {
 	__u8  version;
@@ -62,4 +64,28 @@ struct nvif_vmm_unmap_v0 {
 	__u8  pad01[7];
 	__u64 addr;
 };
+
+struct nvif_vmm_pfnmap_v0 {
+	__u8  version;
+	__u8  page;
+	__u8  pad02[6];
+	__u64 addr;
+	__u64 size;
+#define NVIF_VMM_PFNMAP_V0_ADDR                           0xfffffffffffff000ULL
+#define NVIF_VMM_PFNMAP_V0_ADDR_SHIFT                                        12
+#define NVIF_VMM_PFNMAP_V0_APER                           0x00000000000000f0ULL
+#define NVIF_VMM_PFNMAP_V0_HOST                           0x0000000000000000ULL
+#define NVIF_VMM_PFNMAP_V0_VRAM                           0x0000000000000010ULL
+#define NVIF_VMM_PFNMAP_V0_W                              0x0000000000000002ULL
+#define NVIF_VMM_PFNMAP_V0_V                              0x0000000000000001ULL
+#define NVIF_VMM_PFNMAP_V0_NONE                           0x0000000000000000ULL
+	__u64 phys[];
+};
+
+struct nvif_vmm_pfnclr_v0 {
+	__u8  version;
+	__u8  pad01[7];
+	__u64 addr;
+	__u64 size;
+};
 #endif

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

@@ -64,6 +64,7 @@ struct nvkm_vmm_map {
 	struct nvkm_mm_node *mem;
 	struct scatterlist *sgl;
 	dma_addr_t *dma;
+	u64 *pfn;
 	u64 off;
 
 	const struct nvkm_vmm_page *page;

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

@@ -42,6 +42,69 @@ nvkm_uvmm_search(struct nvkm_client *client, u64 handle)
 	return nvkm_uvmm(object)->vmm;
 }
 
+static int
+nvkm_uvmm_mthd_pfnclr(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
+{
+	struct nvkm_client *client = uvmm->object.client;
+	union {
+		struct nvif_vmm_pfnclr_v0 v0;
+	} *args = argv;
+	struct nvkm_vmm *vmm = uvmm->vmm;
+	int ret = -ENOSYS;
+	u64 addr, size;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, false))) {
+		addr = args->v0.addr;
+		size = args->v0.size;
+	} else
+		return ret;
+
+	if (!client->super)
+		return -ENOENT;
+
+	if (size) {
+		mutex_lock(&vmm->mutex);
+		ret = nvkm_vmm_pfn_unmap(vmm, addr, size);
+		mutex_unlock(&vmm->mutex);
+	}
+
+	return ret;
+}
+
+static int
+nvkm_uvmm_mthd_pfnmap(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
+{
+	struct nvkm_client *client = uvmm->object.client;
+	union {
+		struct nvif_vmm_pfnmap_v0 v0;
+	} *args = argv;
+	struct nvkm_vmm *vmm = uvmm->vmm;
+	int ret = -ENOSYS;
+	u64 addr, size, *phys;
+	u8  page;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, true))) {
+		page = args->v0.page;
+		addr = args->v0.addr;
+		size = args->v0.size;
+		phys = args->v0.phys;
+		if (argc != (size >> page) * sizeof(args->v0.phys[0]))
+			return -EINVAL;
+	} else
+		return ret;
+
+	if (!client->super)
+		return -ENOENT;
+
+	if (size) {
+		mutex_lock(&vmm->mutex);
+		ret = nvkm_vmm_pfn_map(vmm, page, addr, size, phys);
+		mutex_unlock(&vmm->mutex);
+	}
+
+	return ret;
+}
+
 static int
 nvkm_uvmm_mthd_unmap(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
 {
@@ -78,7 +141,7 @@ nvkm_uvmm_mthd_unmap(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
 		goto done;
 	}
 
-	nvkm_vmm_unmap_locked(vmm, vma);
+	nvkm_vmm_unmap_locked(vmm, vma, false);
 	ret = 0;
 done:
 	mutex_unlock(&vmm->mutex);
@@ -124,6 +187,11 @@ nvkm_uvmm_mthd_map(struct nvkm_uvmm *uvmm, void *argv, u32 argc)
 		goto fail;
 	}
 
+	if (ret = -EINVAL, vma->mapped && !vma->memory) {
+		VMM_DEBUG(vmm, "pfnmap %016llx", addr);
+		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)) {
@@ -271,6 +339,8 @@ nvkm_uvmm_mthd(struct nvkm_object *object, u32 mthd, void *argv, u32 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);
+	case NVIF_VMM_V0_PFNMAP: return nvkm_uvmm_mthd_pfnmap(uvmm, argv, argc);
+	case NVIF_VMM_V0_PFNCLR: return nvkm_uvmm_mthd_pfnclr(uvmm, argv, argc);
 	default:
 		break;
 	}