staging: vboxvideo: Add vbox_bo_k[un]map helper functions

Add vbox_bo_k[un]map helper functions instead of having code directly
poking struct vbox_bo internals.

While touch neighboring code anyways also fix a return -PTR_ERR(info),
which should be return PTR_ERR(info).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vboxvideo/vbox_drv.h

@@ -269,6 +269,8 @@ static inline void vbox_bo_unreserve(struct vbox_bo *bo)
 void vbox_ttm_placement(struct vbox_bo *bo, int domain);
 int vbox_bo_push_sysram(struct vbox_bo *bo);
 int vbox_mmap(struct file *filp, struct vm_area_struct *vma);
+void *vbox_bo_kmap(struct vbox_bo *bo);
+void vbox_bo_kunmap(struct vbox_bo *bo);
 
 /* vbox_prime.c */
 int vbox_gem_prime_pin(struct drm_gem_object *obj);

drivers/staging/vboxvideo/vbox_fb.c

@@ -108,15 +108,14 @@ static int vboxfb_create(struct drm_fb_helper *helper,
 	if (ret)
 		return ret;
 
-	ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages, &bo->kmap);
-	if (ret) {
-		DRM_ERROR("failed to kmap fbcon\n");
-		return ret;
-	}
-
 	info = drm_fb_helper_alloc_fbi(helper);
 	if (IS_ERR(info))
-		return -PTR_ERR(info);
+		return PTR_ERR(info);
+
+	info->screen_size = size;
+	info->screen_base = (char __iomem *)vbox_bo_kmap(bo);
+	if (IS_ERR(info->screen_base))
+		return PTR_ERR(info->screen_base);
 
 	info->par = fbdev;
 
@@ -150,9 +149,6 @@ static int vboxfb_create(struct drm_fb_helper *helper,
 	info->fix.smem_start = info->apertures->ranges[0].base + gpu_addr;
 	info->fix.smem_len = vbox->available_vram_size - gpu_addr;
 
-	info->screen_base = (char __iomem *)bo->kmap.virtual;
-	info->screen_size = size;
-
 #ifdef CONFIG_DRM_KMS_FB_HELPER
 	info->fbdefio = &vbox_defio;
 	fb_deferred_io_init(info);
@@ -184,8 +180,7 @@ void vbox_fbdev_fini(struct vbox_private *vbox)
 	if (afb->obj) {
 		struct vbox_bo *bo = gem_to_vbox_bo(afb->obj);
 
-		if (bo->kmap.virtual)
-			ttm_bo_kunmap(&bo->kmap);
+		vbox_bo_kunmap(bo);
 
 		if (bo->pin_count)
 			vbox_bo_unpin(bo);

drivers/staging/vboxvideo/vbox_ttm.c

@@ -418,8 +418,10 @@ int vbox_bo_push_sysram(struct vbox_bo *bo)
 	if (bo->pin_count)
 		return 0;
 
-	if (bo->kmap.virtual)
+	if (bo->kmap.virtual) {
 		ttm_bo_kunmap(&bo->kmap);
+		bo->kmap.virtual = NULL;
+	}
 
 	vbox_ttm_placement(bo, TTM_PL_FLAG_SYSTEM);
 
@@ -448,3 +450,27 @@ int vbox_mmap(struct file *filp, struct vm_area_struct *vma)
 
 	return ttm_bo_mmap(filp, vma, &vbox->ttm.bdev);
 }
+
+void *vbox_bo_kmap(struct vbox_bo *bo)
+{
+	int ret;
+
+	if (bo->kmap.virtual)
+		return bo->kmap.virtual;
+
+	ret = ttm_bo_kmap(&bo->bo, 0, bo->bo.num_pages, &bo->kmap);
+	if (ret) {
+		DRM_ERROR("Error kmapping bo: %d\n", ret);
+		return NULL;
+	}
+
+	return bo->kmap.virtual;
+}
+
+void vbox_bo_kunmap(struct vbox_bo *bo)
+{
+	if (bo->kmap.virtual) {
+		ttm_bo_kunmap(&bo->kmap);
+		bo->kmap.virtual = NULL;
+	}
+}