drm/udl: Remove flags field from struct udl_gem_object

The flags field in struct udl_gem controls mapping parameters: cached
access for local buffers, write-combined access for imported buffers.

We can drop the field and distinguish both cases by testing whether
struct drm_gem_object.import_attach is NULL.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191107094307.19870-2-tzimmermann@suse.de

drivers/gpu/drm/udl/udl_dmabuf.c

@@ -241,7 +241,6 @@ struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
 		goto fail_unmap;
 
 	uobj->base.import_attach = attach;
-	uobj->flags = UDL_BO_WC;
 
 	return &uobj->base;
 

drivers/gpu/drm/udl/udl_drv.h

@@ -29,9 +29,6 @@ struct drm_mode_create_dumb;
 #define DRIVER_MINOR		0
 #define DRIVER_PATCHLEVEL	1
 
-#define UDL_BO_CACHEABLE		(1 << 0)
-#define UDL_BO_WC		(1 << 1)
-
 struct udl_device;
 
 struct urb_node {
@@ -81,7 +78,6 @@ struct udl_gem_object {
 	struct page **pages;
 	void *vmapping;
 	struct sg_table *sg;
-	unsigned int flags;
 };
 
 #define to_udl_bo(x) container_of(x, struct udl_gem_object, base)

drivers/gpu/drm/udl/udl_gem.c

@@ -25,7 +25,6 @@ struct udl_gem_object *udl_gem_alloc_object(struct drm_device *dev,
 		return NULL;
 	}
 
-	obj->flags = UDL_BO_CACHEABLE;
 	return obj;
 }
 
@@ -57,23 +56,6 @@ udl_gem_create(struct drm_file *file,
 	return 0;
 }
 
-static void update_vm_cache_attr(struct udl_gem_object *obj,
-				 struct vm_area_struct *vma)
-{
-	DRM_DEBUG_KMS("flags = 0x%x\n", obj->flags);
-
-	/* non-cacheable as default. */
-	if (obj->flags & UDL_BO_CACHEABLE) {
-		vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-	} else if (obj->flags & UDL_BO_WC) {
-		vma->vm_page_prot =
-			pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
-	} else {
-		vma->vm_page_prot =
-			pgprot_noncached(vm_get_page_prot(vma->vm_flags));
-	}
-}
-
 int udl_dumb_create(struct drm_file *file,
 		    struct drm_device *dev,
 		    struct drm_mode_create_dumb *args)
@@ -86,16 +68,21 @@ int udl_dumb_create(struct drm_file *file,
 
 int udl_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 {
+	struct drm_gem_object *obj;
 	int ret;
 
 	ret = drm_gem_mmap(filp, vma);
 	if (ret)
 		return ret;
 
+	obj = vma->vm_private_data;
+
 	vma->vm_flags &= ~VM_PFNMAP;
 	vma->vm_flags |= VM_MIXEDMAP;
 
-	update_vm_cache_attr(to_udl_bo(vma->vm_private_data), vma);
+	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+	if (obj->import_attach)
+		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
 
 	return ret;
 }