drm/syncobj: add sync_file interaction. (v1.2)

This interface allows importing the fence from a sync_file into
an existing drm sync object, or exporting the fence attached to
an existing drm sync object into a new sync file object.

This should only be used to interact with sync files where necessary.

v1.1: fence put fixes (Chris), drop fence from ioctl names (Chris)
fixup for new fence replace API.

Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

2 files changed, 75 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_syncobj.c b/drivers/gpu/drm/drm_syncobj.c
index 7144825d45f2..89441bc78591 100644
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -45,6 +45,7 @@
 #include <linux/file.h>
 #include <linux/fs.h>
 #include <linux/anon_inodes.h>
+#include <linux/sync_file.h>
 
 #include "drm_internal.h"
 #include <drm/drm_syncobj.h>
@@ -276,6 +277,59 @@ static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
         return 0;
 }
 
+int drm_syncobj_import_sync_file_fence(struct drm_file *file_private,
+                                       int fd, int handle)
+{
+        struct dma_fence *fence = sync_file_get_fence(fd);
+        struct drm_syncobj *syncobj;
+
+        if (!fence)
+                return -EINVAL;
+
+        syncobj = drm_syncobj_find(file_private, handle);
+        if (!syncobj) {
+                dma_fence_put(fence);
+                return -ENOENT;
+        }
+
+        drm_syncobj_replace_fence(file_private, syncobj, fence);
+        dma_fence_put(fence);
+        drm_syncobj_put(syncobj);
+        return 0;
+}
+
+int drm_syncobj_export_sync_file(struct drm_file *file_private,
+                                 int handle, int *p_fd)
+{
+        int ret;
+        struct dma_fence *fence;
+        struct sync_file *sync_file;
+        int fd = get_unused_fd_flags(O_CLOEXEC);
+
+        if (fd < 0)
+                return fd;
+
+        ret = drm_syncobj_fence_get(file_private, handle, &fence);
+        if (ret)
+                goto err_put_fd;
+
+        sync_file = sync_file_create(fence);
+
+        dma_fence_put(fence);
+
+        if (!sync_file) {
+                ret = -EINVAL;
+                goto err_put_fd;
+        }
+
+        fd_install(fd, sync_file->file);
+
+        *p_fd = fd;
+        return 0;
+err_put_fd:
+        put_unused_fd(fd);
+        return ret;
+}
 /**
  * drm_syncobj_open - initalizes syncobj file-private structures at devnode open time
  * @dev: drm_device which is being opened by userspace
@@ -358,9 +412,17 @@ drm_syncobj_handle_to_fd_ioctl(struct drm_device *dev, void *data,
         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
                 return -ENODEV;
 
-        if (args->pad || args->flags)
+        if (args->pad)
                 return -EINVAL;
 
+        if (args->flags != 0 &&
+            args->flags != DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
+                return -EINVAL;
+
+        if (args->flags & DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE)
+                return drm_syncobj_export_sync_file(file_private, args->handle,
+                                                    &args->fd);
+
         return drm_syncobj_handle_to_fd(file_private, args->handle,
                                         &args->fd);
 }
@@ -374,9 +436,18 @@ drm_syncobj_fd_to_handle_ioctl(struct drm_device *dev, void *data,
         if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
                 return -ENODEV;
 
-        if (args->pad || args->flags)
+        if (args->pad)
+                return -EINVAL;
+
+        if (args->flags != 0 &&
+            args->flags != DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
                 return -EINVAL;
 
+        if (args->flags & DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE)
+                return drm_syncobj_import_sync_file_fence(file_private,
+                                                          args->fd,
+                                                          args->handle);
+
         return drm_syncobj_fd_to_handle(file_private, args->fd,
                                         &args->handle);
 }
diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h
index 96c5c789e73d..101593ab10ac 100644
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -708,6 +708,8 @@ struct drm_syncobj_destroy {
         __u32 pad;
 };
 
+#define DRM_SYNCOBJ_FD_TO_HANDLE_FLAGS_IMPORT_SYNC_FILE (1 << 0)
+#define DRM_SYNCOBJ_HANDLE_TO_FD_FLAGS_EXPORT_SYNC_FILE (1 << 0)
 struct drm_syncobj_handle {
         __u32 handle;
         __u32 flags;