drm/drm_property: make replace_property_blob_from_id a DRM helper

Place it in drm_property where drm_property_replace_blob and
drm_property_lookup_blob live. Then we can use the DRM helper for
driver-specific KMS properties too.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Melissa Wen <mwen@igalia.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 59 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_property.c b/drivers/gpu/drm/drm_property.c
index dfec479830e4..596272149a35 100644
--- a/drivers/gpu/drm/drm_property.c
+++ b/drivers/gpu/drm/drm_property.c
@@ -27,6 +27,7 @@
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
 #include <drm/drm_framebuffer.h>
+#include <drm/drm_print.h>
 #include <drm/drm_property.h>
 
 #include "drm_crtc_internal.h"
@@ -751,6 +752,64 @@ bool drm_property_replace_blob(struct drm_property_blob **blob,
 }
 EXPORT_SYMBOL(drm_property_replace_blob);
 
+/**
+ * drm_property_replace_blob_from_id - replace a blob property taking a reference
+ * @dev: DRM device
+ * @blob: a pointer to the member blob to be replaced
+ * @blob_id: the id of the new blob to replace with
+ * @expected_size: expected size of the blob property
+ * @expected_elem_size: expected size of an element in the blob property
+ * @replaced: if the blob was in fact replaced
+ *
+ * Look up the new blob from id, take its reference, check expected sizes of
+ * the blob and its element and replace the old blob by the new one. Advertise
+ * if the replacement operation was successful.
+ *
+ * Return: true if the blob was in fact replaced. -EINVAL if the new blob was
+ * not found or sizes don't match.
+ */
+int drm_property_replace_blob_from_id(struct drm_device *dev,
+					 struct drm_property_blob **blob,
+					 uint64_t blob_id,
+					 ssize_t expected_size,
+					 ssize_t expected_elem_size,
+					 bool *replaced)
+{
+	struct drm_property_blob *new_blob = NULL;
+
+	if (blob_id != 0) {
+		new_blob = drm_property_lookup_blob(dev, blob_id);
+		if (new_blob == NULL) {
+			drm_dbg_atomic(dev,
+				       "cannot find blob ID %llu\n", blob_id);
+			return -EINVAL;
+		}
+
+		if (expected_size > 0 &&
+		    new_blob->length != expected_size) {
+			drm_dbg_atomic(dev,
+				       "[BLOB:%d] length %zu different from expected %zu\n",
+				       new_blob->base.id, new_blob->length, expected_size);
+			drm_property_blob_put(new_blob);
+			return -EINVAL;
+		}
+		if (expected_elem_size > 0 &&
+		    new_blob->length % expected_elem_size != 0) {
+			drm_dbg_atomic(dev,
+				       "[BLOB:%d] length %zu not divisible by element size %zu\n",
+				       new_blob->base.id, new_blob->length, expected_elem_size);
+			drm_property_blob_put(new_blob);
+			return -EINVAL;
+		}
+	}
+
+	*replaced |= drm_property_replace_blob(blob, new_blob);
+	drm_property_blob_put(new_blob);
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_property_replace_blob_from_id);
+
 int drm_mode_getblob_ioctl(struct drm_device *dev,
 			   void *data, struct drm_file *file_priv)
 {