drm/msm/mdp4: use msm_kms_init_vm() instead of duplicating it

Use the msm_kms_init_vm() function to allocate memory manager instead of
hand-coding a copy of it. Although MDP4 platforms don't have MDSS
device, it's still safe to use the function as all MDP4 devices have
IOMMU and the parent of the MDP4 is the root SoC device.

Signed-off-by: Dmitry Baryshkov <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/672563/
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/msm/disp/dpu1/dpu_kms.c

···
 {
 	struct drm_gpuvm *vm;
 
-	vm = msm_kms_init_vm(dpu_kms->dev);
+	vm = msm_kms_init_vm(dpu_kms->dev, dpu_kms->dev->dev->parent);
 	if (IS_ERR(vm))
 		return PTR_ERR(vm);
 

drivers/gpu/drm/msm/disp/mdp4/mdp4_kms.c

···
 
 static int mdp4_kms_init(struct drm_device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev->dev);
 	struct msm_drm_private *priv = dev->dev_private;
 	struct mdp4_kms *mdp4_kms = to_mdp4_kms(to_mdp_kms(priv->kms));
 	struct msm_kms *kms = NULL;
-	struct msm_mmu *mmu;
 	struct drm_gpuvm *vm;
 	int ret;
 	u32 major, minor;
···
 	mdp4_disable(mdp4_kms);
 	mdelay(16);
 
-	if (!device_iommu_mapped(&pdev->dev)) {
-		DRM_DEV_INFO(dev->dev, "no IOMMU, bailing out\n");
-		ret = -ENODEV;
+	vm = msm_kms_init_vm(mdp4_kms->dev, NULL);
+	if (IS_ERR(vm)) {
+		ret = PTR_ERR(vm);
 		goto fail;
 	}
 
-	mmu = msm_iommu_new(&pdev->dev, 0);
-	if (IS_ERR(mmu)) {
-		ret = PTR_ERR(mmu);
-		goto fail;
-	} else {
-		vm  = msm_gem_vm_create(dev, mmu, "mdp4",
-					0x1000, 0x100000000 - 0x1000,
-					true);
-
-		if (IS_ERR(vm)) {
-			if (!IS_ERR(mmu))
-				mmu->funcs->destroy(mmu);
-			ret = PTR_ERR(vm);
-			goto fail;
-		}
-
-		kms->vm = vm;
-	}
+	kms->vm = vm;
 
 	ret = modeset_init(mdp4_kms);
 	if (ret) {

drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c

···
 	}
 	mdelay(16);
 
-	vm = msm_kms_init_vm(mdp5_kms->dev);
+	vm = msm_kms_init_vm(mdp5_kms->dev, pdev->dev.parent);
 	if (IS_ERR(vm)) {
 		ret = PTR_ERR(vm);
 		goto fail;

drivers/gpu/drm/msm/msm_drv.h

···
 int msm_register_mmu(struct drm_device *dev, struct msm_mmu *mmu);
 void msm_unregister_mmu(struct drm_device *dev, struct msm_mmu *mmu);
 
-struct drm_gpuvm *msm_kms_init_vm(struct drm_device *dev);
+struct drm_gpuvm *msm_kms_init_vm(struct drm_device *dev, struct device *mdss_dev);
 bool msm_use_mmu(struct drm_device *dev);
 
 int msm_ioctl_gem_submit(struct drm_device *dev, void *data,

drivers/gpu/drm/msm/msm_kms.c

···
 	return -ENOSYS;
 }
 
-struct drm_gpuvm *msm_kms_init_vm(struct drm_device *dev)
+struct drm_gpuvm *msm_kms_init_vm(struct drm_device *dev, struct device *mdss_dev)
 {
 	struct drm_gpuvm *vm;
 	struct msm_mmu *mmu;
 	struct device *mdp_dev = dev->dev;
-	struct device *mdss_dev = mdp_dev->parent;
 	struct msm_drm_private *priv = dev->dev_private;
 	struct msm_kms *kms = priv->kms;
 	struct device *iommu_dev;
···
 	 */
 	if (device_iommu_mapped(mdp_dev))
 		iommu_dev = mdp_dev;
-	else if (device_iommu_mapped(mdss_dev))
+	else if (mdss_dev && device_iommu_mapped(mdss_dev))
 		iommu_dev = mdss_dev;
 	else {
 		drm_info(dev, "no IOMMU, bailing out\n");