4 files changed, 84 insertions, 72 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 542401659013..c262d5184e12 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2169,10 +2169,7 @@ struct drm_i915_gem_object {
 		struct scatterlist *sg;
 		int last;
 	} get_page;
-
-	/* prime dma-buf support */
-	void *dma_buf_vmapping;
-	int vmapping_count;
+	void *mapping;
 
 	/** Breadcrumb of last rendering to the buffer.
 	 * There can only be one writer, but we allow for multiple readers.
@@ -2988,12 +2985,44 @@ static inline void i915_gem_object_pin_pages(struct drm_i915_gem_object *obj)
 	BUG_ON(obj->pages == NULL);
 	obj->pages_pin_count++;
 }
+
 static inline void i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj)
 {
 	BUG_ON(obj->pages_pin_count == 0);
 	obj->pages_pin_count--;
 }
 
+/**
+ * i915_gem_object_pin_map - return a contiguous mapping of the entire object
+ * @obj - the object to map into kernel address space
+ *
+ * Calls i915_gem_object_pin_pages() to prevent reaping of the object's
+ * pages and then returns a contiguous mapping of the backing storage into
+ * the kernel address space.
+ *
+ * The caller must hold the struct_mutex.
+ *
+ * Returns the pointer through which to access the backing storage.
+ */
+void *__must_check i915_gem_object_pin_map(struct drm_i915_gem_object *obj);
+
+/**
+ * i915_gem_object_unpin_map - releases an earlier mapping
+ * @obj - the object to unmap
+ *
+ * After pinning the object and mapping its pages, once you are finished
+ * with your access, call i915_gem_object_unpin_map() to release the pin
+ * upon the mapping. Once the pin count reaches zero, that mapping may be
+ * removed.
+ *
+ * The caller must hold the struct_mutex.
+ */
+static inline void i915_gem_object_unpin_map(struct drm_i915_gem_object *obj)
+{
+	lockdep_assert_held(&obj->base.dev->struct_mutex);
+	i915_gem_object_unpin_pages(obj);
+}
+
 int __must_check i915_mutex_lock_interruptible(struct drm_device *dev);
 int i915_gem_object_sync(struct drm_i915_gem_object *obj,
 			 struct intel_engine_cs *to,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 339d183f05b0..55ad50bc3921 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2232,6 +2232,11 @@ i915_gem_object_put_pages(struct drm_i915_gem_object *obj)
 	 * lists early. */
 	list_del(&obj->global_list);
 
+	if (obj->mapping) {
+		vunmap(obj->mapping);
+		obj->mapping = NULL;
+	}
+
 	ops->put_pages(obj);
 	obj->pages = NULL;
 
@@ -2400,6 +2405,45 @@ i915_gem_object_get_pages(struct drm_i915_gem_object *obj)
 	return 0;
 }
 
+void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj)
+{
+	int ret;
+
+	lockdep_assert_held(&obj->base.dev->struct_mutex);
+
+	ret = i915_gem_object_get_pages(obj);
+	if (ret)
+		return ERR_PTR(ret);
+
+	i915_gem_object_pin_pages(obj);
+
+	if (obj->mapping == NULL) {
+		struct sg_page_iter sg_iter;
+		struct page **pages;
+		int n;
+
+		n = obj->base.size >> PAGE_SHIFT;
+		pages = kmalloc(n*sizeof(*pages), GFP_TEMPORARY | __GFP_NOWARN);
+		if (pages == NULL)
+			pages = drm_malloc_ab(n, sizeof(*pages));
+		if (pages != NULL) {
+			n = 0;
+			for_each_sg_page(obj->pages->sgl, &sg_iter,
+					 obj->pages->nents, 0)
+				pages[n++] = sg_page_iter_page(&sg_iter);
+
+			obj->mapping = vmap(pages, n, 0, PAGE_KERNEL);
+			drm_free_large(pages);
+		}
+		if (obj->mapping == NULL) {
+			i915_gem_object_unpin_pages(obj);
+			return ERR_PTR(-ENOMEM);
+		}
+	}
+
+	return obj->mapping;
+}
+
 void i915_vma_move_to_active(struct i915_vma *vma,
 			     struct drm_i915_gem_request *req)
 {
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index 616f07830b7e..4e60643ef53a 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -108,51 +108,17 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
 	struct drm_device *dev = obj->base.dev;
-	struct sg_page_iter sg_iter;
-	struct page **pages;
-	int ret, i;
+	void *addr;
+	int ret;
 
 	ret = i915_mutex_lock_interruptible(dev);
 	if (ret)
 		return ERR_PTR(ret);
 
-	if (obj->dma_buf_vmapping) {
-		obj->vmapping_count++;
-		goto out_unlock;
-	}
-
-	ret = i915_gem_object_get_pages(obj);
-	if (ret)
-		goto err;
-
-	i915_gem_object_pin_pages(obj);
-
-	ret = -ENOMEM;
-
-	pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
-	if (pages == NULL)
-		goto err_unpin;
-
-	i = 0;
-	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
-		pages[i++] = sg_page_iter_page(&sg_iter);
-
-	obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
-	drm_free_large(pages);
-
-	if (!obj->dma_buf_vmapping)
-		goto err_unpin;
-
-	obj->vmapping_count = 1;
-out_unlock:
+	addr = i915_gem_object_pin_map(obj);
 	mutex_unlock(&dev->struct_mutex);
-	return obj->dma_buf_vmapping;
 
-err_unpin:
-	i915_gem_object_unpin_pages(obj);
-err:
-	mutex_unlock(&dev->struct_mutex);
-	return ERR_PTR(ret);
+	return addr;
 }
 
 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
@@ -161,12 +127,7 @@ static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
 	struct drm_device *dev = obj->base.dev;
 
 	mutex_lock(&dev->struct_mutex);
-	if (--obj->vmapping_count == 0) {
-		vunmap(obj->dma_buf_vmapping);
-		obj->dma_buf_vmapping = NULL;
-
-		i915_gem_object_unpin_pages(obj);
-	}
+	i915_gem_object_unpin_map(obj);
 	mutex_unlock(&dev->struct_mutex);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index a6e187620c41..41b604e69db7 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2083,35 +2083,13 @@ static int init_phys_status_page(struct intel_engine_cs *engine)
 void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf)
 {
 	if (HAS_LLC(ringbuf->obj->base.dev) && !ringbuf->obj->stolen)
-		vunmap(ringbuf->virtual_start);
+		i915_gem_object_unpin_map(ringbuf->obj);
 	else
 		iounmap(ringbuf->virtual_start);
-	ringbuf->virtual_start = NULL;
 	ringbuf->vma = NULL;
 	i915_gem_object_ggtt_unpin(ringbuf->obj);
 }
 
-static u32 *vmap_obj(struct drm_i915_gem_object *obj)
-{
-	struct sg_page_iter sg_iter;
-	struct page **pages;
-	void *addr;
-	int i;
-
-	pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
-	if (pages == NULL)
-		return NULL;
-
-	i = 0;
-	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
-		pages[i++] = sg_page_iter_page(&sg_iter);
-
-	addr = vmap(pages, i, 0, PAGE_KERNEL);
-	drm_free_large(pages);
-
-	return addr;
-}
-
 int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
 				     struct intel_ringbuffer *ringbuf)
 {
@@ -2129,7 +2107,7 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
 		if (ret)
 			goto err_unpin;
 
-		ringbuf->virtual_start = vmap_obj(obj);
+		ringbuf->virtual_start = i915_gem_object_pin_map(obj);
 		if (ringbuf->virtual_start == NULL) {
 			ret = -ENOMEM;
 			goto err_unpin;