udl: add prime fd->handle support.

udl can only be used as an output offload so doesn't need to support
handle->fd direction.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/udl/udl_drv.c

@@ -57,7 +57,7 @@ static const struct file_operations udl_driver_fops = {
 };
 
 static struct drm_driver driver = {
-	.driver_features = DRIVER_MODESET | DRIVER_GEM,
+	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME,
 	.load = udl_driver_load,
 	.unload = udl_driver_unload,
 
@@ -70,6 +70,10 @@ static struct drm_driver driver = {
 	.dumb_map_offset = udl_gem_mmap,
 	.dumb_destroy = udl_dumb_destroy,
 	.fops = &udl_driver_fops,
+
+	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
+	.gem_prime_import = udl_gem_prime_import,
+
 	.name = DRIVER_NAME,
 	.desc = DRIVER_DESC,
 	.date = DRIVER_DATE,

drivers/gpu/drm/udl/udl_drv.h

@@ -66,6 +66,7 @@ struct udl_gem_object {
 	struct drm_gem_object base;
 	struct page **pages;
 	void *vmapping;
+	struct sg_table *sg;
 };
 
 #define to_udl_bo(x) container_of(x, struct udl_gem_object, base)
@@ -118,6 +119,8 @@ int udl_gem_init_object(struct drm_gem_object *obj);
 void udl_gem_free_object(struct drm_gem_object *gem_obj);
 struct udl_gem_object *udl_gem_alloc_object(struct drm_device *dev,
 					    size_t size);
+struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
+				struct dma_buf *dma_buf);
 
 int udl_gem_vmap(struct udl_gem_object *obj);
 void udl_gem_vunmap(struct udl_gem_object *obj);

drivers/gpu/drm/udl/udl_fb.c

@@ -593,11 +593,20 @@ udl_fb_user_fb_create(struct drm_device *dev,
 	struct drm_gem_object *obj;
 	struct udl_framebuffer *ufb;
 	int ret;
+	uint32_t size;
 
 	obj = drm_gem_object_lookup(dev, file, mode_cmd->handles[0]);
 	if (obj == NULL)
 		return ERR_PTR(-ENOENT);
 
+	size = mode_cmd->pitches[0] * mode_cmd->height;
+	size = ALIGN(size, PAGE_SIZE);
+
+	if (size > obj->size) {
+		DRM_ERROR("object size not sufficient for fb %d %zu %d %d\n", size, obj->size, mode_cmd->pitches[0], mode_cmd->height);
+		return ERR_PTR(-ENOMEM);
+	}
+
 	ufb = kzalloc(sizeof(*ufb), GFP_KERNEL);
 	if (ufb == NULL)
 		return ERR_PTR(-ENOMEM);

drivers/gpu/drm/udl/udl_gem.c

@@ -9,6 +9,7 @@
 #include "drmP.h"
 #include "udl_drv.h"
 #include <linux/shmem_fs.h>
+#include <linux/dma-buf.h>
 
 struct udl_gem_object *udl_gem_alloc_object(struct drm_device *dev,
 					    size_t size)
@@ -161,6 +162,12 @@ static void udl_gem_put_pages(struct udl_gem_object *obj)
 	int page_count = obj->base.size / PAGE_SIZE;
 	int i;
 
+	if (obj->base.import_attach) {
+		drm_free_large(obj->pages);
+		obj->pages = NULL;
+		return;
+	}
+
 	for (i = 0; i < page_count; i++)
 		page_cache_release(obj->pages[i]);
 
@@ -195,6 +202,9 @@ void udl_gem_free_object(struct drm_gem_object *gem_obj)
 {
 	struct udl_gem_object *obj = to_udl_bo(gem_obj);
 
+	if (gem_obj->import_attach)
+		drm_prime_gem_destroy(gem_obj, obj->sg);
+
 	if (obj->vmapping)
 		udl_gem_vunmap(obj);
 
@@ -239,3 +249,68 @@ unlock:
 	mutex_unlock(&dev->struct_mutex);
 	return ret;
 }
+
+static int udl_prime_create(struct drm_device *dev,
+			    size_t size,
+			    struct sg_table *sg,
+			    struct udl_gem_object **obj_p)
+{
+	struct udl_gem_object *obj;
+	int npages;
+	int i;
+	struct scatterlist *iter;
+
+	npages = size / PAGE_SIZE;
+
+	*obj_p = NULL;
+	obj = udl_gem_alloc_object(dev, npages * PAGE_SIZE);
+	if (!obj)
+		return -ENOMEM;
+
+	obj->sg = sg;
+	obj->pages = drm_malloc_ab(npages, sizeof(struct page *));
+	if (obj->pages == NULL) {
+		DRM_ERROR("obj pages is NULL %d\n", npages);
+		return -ENOMEM;
+	}
+
+	drm_prime_sg_to_page_addr_arrays(sg, obj->pages, NULL, npages);
+
+	*obj_p = obj;
+	return 0;
+}
+
+struct drm_gem_object *udl_gem_prime_import(struct drm_device *dev,
+				struct dma_buf *dma_buf)
+{
+	struct dma_buf_attachment *attach;
+	struct sg_table *sg;
+	struct udl_gem_object *uobj;
+	int ret;
+
+	/* need to attach */
+	attach = dma_buf_attach(dma_buf, dev->dev);
+	if (IS_ERR(attach))
+		return ERR_PTR(PTR_ERR(attach));
+
+	sg = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sg)) {
+		ret = PTR_ERR(sg);
+		goto fail_detach;
+	}
+
+	ret = udl_prime_create(dev, dma_buf->size, sg, &uobj);
+	if (ret) {
+		goto fail_unmap;
+	}
+
+	uobj->base.import_attach = attach;
+
+	return &uobj->base;
+
+fail_unmap:
+	dma_buf_unmap_attachment(attach, sg, DMA_BIDIRECTIONAL);
+fail_detach:
+	dma_buf_detach(dma_buf, attach);
+	return ERR_PTR(ret);
+}