drm/msm: Add hint to DRM_IOCTL_MSM_GEM_INFO to return an object IOVA

Modify the 'pad' member of struct drm_msm_gem_info to 'flags'. If the
user sets 'flags' to non-zero it means that they want a IOVA for the
GEM object instead of a mmap() offset. Return the iova in the 'offset'
member.

Signed-off-by: Jordan Crouse <[e-mail]>
[robclark: s/hint/flags in commit msg]
Signed-off-by: Rob Clark <[e-mail]>

drivers/gpu/drm/msm/msm_drv.c

···
 	return ret;
 }
 
+static int msm_ioctl_gem_info_iova(struct drm_device *dev,
+		struct drm_gem_object *obj, uint64_t *iova)
+{
+	struct msm_drm_private *priv = dev->dev_private;
+
+	if (!priv->gpu)
+		return -EINVAL;
+
+	return msm_gem_get_iova(obj, priv->gpu->id, iova);
+}
+
 static int msm_ioctl_gem_info(struct drm_device *dev, void *data,
 		struct drm_file *file)
 {
···
 	struct drm_gem_object *obj;
 	int ret = 0;
 
-	if (args->pad)
+	if (args->flags & ~MSM_INFO_FLAGS)
 		return -EINVAL;
 
 	obj = drm_gem_object_lookup(file, args->handle);
 	if (!obj)
 		return -ENOENT;
 
-	args->offset = msm_gem_mmap_offset(obj);
+	if (args->flags & MSM_INFO_IOVA) {
+		uint64_t iova;
+
+		ret = msm_ioctl_gem_info_iova(dev, obj, &iova);
+		if (!ret)
+			args->offset = iova;
+	} else {
+		args->offset = msm_gem_mmap_offset(obj);
+	}
 
 	drm_gem_object_unreference_unlocked(obj);
 

include/uapi/drm/msm_drm.h

···
 	__u32 handle;         /* out */
 };
 
+#define MSM_INFO_IOVA	0x01
+
+#define MSM_INFO_FLAGS (MSM_INFO_IOVA)
+
 struct drm_msm_gem_info {
 	__u32 handle;         /* in */
-	__u32 pad;
-	__u64 offset;         /* out, offset to pass to mmap() */
+	__u32 flags;	      /* in - combination of MSM_INFO_* flags */
+	__u64 offset;         /* out, mmap() offset or iova */
 };
 
 #define MSM_PREP_READ        0x01