staging: drm/omap: dmabuf/prime support

For now just implementing the exporting APIs, not yet importing.  And
kmap is rejected on tiled buffers (although the usefulness of that seems
questionable, but could be added later if needed).

Signed-off-by: Rob Clark <rob@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 25 insertions, 1 deletions

diff --git a/drivers/staging/omapdrm/omap_gem.c b/drivers/staging/omapdrm/omap_gem.c
index 921f058cc6a4..c5ba334ac6bf 100644
--- a/drivers/staging/omapdrm/omap_gem.c
+++ b/drivers/staging/omapdrm/omap_gem.c
@@ -266,6 +266,12 @@ static void omap_gem_detach_pages(struct drm_gem_object *obj)
 	omap_obj->pages = NULL;
 }
 
+/* get buffer flags */
+uint32_t omap_gem_flags(struct drm_gem_object *obj)
+{
+	return to_omap_bo(obj)->flags;
+}
+
 /** get mmap offset */
 static uint64_t mmap_offset(struct drm_gem_object *obj)
 {
@@ -764,9 +770,27 @@ static int get_pages(struct drm_gem_object *obj, struct page ***pages)
 	return 0;
 }
 
-int omap_gem_get_pages(struct drm_gem_object *obj, struct page ***pages)
+/* if !remap, and we don't have pages backing, then fail, rather than
+ * increasing the pin count (which we don't really do yet anyways,
+ * because we don't support swapping pages back out).  And 'remap'
+ * might not be quite the right name, but I wanted to keep it working
+ * similarly to omap_gem_get_paddr().  Note though that mutex is not
+ * aquired if !remap (because this can be called in atomic ctxt),
+ * but probably omap_gem_get_paddr() should be changed to work in the
+ * same way.  If !remap, a matching omap_gem_put_pages() call is not
+ * required (and should not be made).
+ */
+int omap_gem_get_pages(struct drm_gem_object *obj, struct page ***pages,
+		bool remap)
 {
 	int ret;
+	if (!remap) {
+		struct omap_gem_object *omap_obj = to_omap_bo(obj);
+		if (!omap_obj->pages)
+			return -ENOMEM;
+		*pages = omap_obj->pages;
+		return 0;
+	}
 	mutex_lock(&obj->dev->struct_mutex);
 	ret = get_pages(obj, pages);
 	mutex_unlock(&obj->dev->struct_mutex);