From: Jason Ekstrand <jason@jlekstrand.net>
Date: Mon, 28 Aug 2017 14:10:28 -0700
Subject: drm/syncobj: Add a signal ioctl (v3)
Git-commit: ffa9443fb3d3eddf0fdf6ac473dc8b5c87f08f15
Patch-mainline: v4.14-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

This IOCTL provides a mechanism for userspace to trigger a sync object
directly.  There are other ways that userspace can trigger a syncobj
such as submitting a dummy batch somewhere or hanging on to a triggered
sync_file and doing an import.  This just provides an easy way to
manually trigger the sync object without weird hacks.

The motivation for this IOCTL is Vulkan fences.  Vulkan lets you create
a fence already in the signaled state so that you can wait on it
immediatly without stalling.  We could also handle this with a new
create flag to ask the driver to create a syncobj that is already
signaled but the IOCTL seemed a bit cleaner and more generic.

v2:
 - Take an array of sync objects (Dave Airlie)
v3:
 - Throw -EINVAL if pad != 0

Signed-off-by: Jason Ekstrand <jason@jlekstrand.net>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/drm_internal.h |    2 ++
 drivers/gpu/drm/drm_ioctl.c    |    2 ++
 drivers/gpu/drm/drm_syncobj.c  |   36 ++++++++++++++++++++++++++++++++++++
 include/uapi/drm/drm.h         |    1 +
 4 files changed, 41 insertions(+)

--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -171,3 +171,5 @@ int drm_syncobj_wait_ioctl(struct drm_de
 			   struct drm_file *file_private);
 int drm_syncobj_reset_ioctl(struct drm_device *dev, void *data,
 			    struct drm_file *file_private);
+int drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
+			     struct drm_file *file_private);
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -661,6 +661,8 @@ static const struct drm_ioctl_desc drm_i
 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_RESET, drm_syncobj_reset_ioctl,
 		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF(DRM_IOCTL_SYNCOBJ_SIGNAL, drm_syncobj_signal_ioctl,
+		      DRM_UNLOCKED|DRM_RENDER_ALLOW),
 };
 
 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
--- a/drivers/gpu/drm/drm_syncobj.c
+++ b/drivers/gpu/drm/drm_syncobj.c
@@ -918,3 +918,39 @@ drm_syncobj_reset_ioctl(struct drm_devic
 
 	return 0;
 }
+
+int
+drm_syncobj_signal_ioctl(struct drm_device *dev, void *data,
+			 struct drm_file *file_private)
+{
+	struct drm_syncobj_array *args = data;
+	struct drm_syncobj **syncobjs;
+	uint32_t i;
+	int ret;
+
+	if (!drm_core_check_feature(dev, DRIVER_SYNCOBJ))
+		return -ENODEV;
+
+	if (args->pad != 0)
+		return -EINVAL;
+
+	if (args->count_handles == 0)
+		return -EINVAL;
+
+	ret = drm_syncobj_array_find(file_private,
+				     u64_to_user_ptr(args->handles),
+				     args->count_handles,
+				     &syncobjs);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < args->count_handles; i++) {
+		ret = drm_syncobj_assign_null_handle(syncobjs[i]);
+		if (ret < 0)
+			break;
+	}
+
+	drm_syncobj_array_free(syncobjs, args->count_handles);
+
+	return ret;
+}
--- a/include/uapi/drm/drm.h
+++ b/include/uapi/drm/drm.h
@@ -861,6 +861,7 @@ extern "C" {
 #define DRM_IOCTL_SYNCOBJ_FD_TO_HANDLE	DRM_IOWR(0xC2, struct drm_syncobj_handle)
 #define DRM_IOCTL_SYNCOBJ_WAIT		DRM_IOWR(0xC3, struct drm_syncobj_wait)
 #define DRM_IOCTL_SYNCOBJ_RESET		DRM_IOWR(0xC4, struct drm_syncobj_array)
+#define DRM_IOCTL_SYNCOBJ_SIGNAL	DRM_IOWR(0xC5, struct drm_syncobj_array)
 
 /**
  * Device specific ioctls should only be in their respective headers