drm/tegra: Deliver syncpoint base to user space

This patch adds a separate ioctl for delivering syncpoint base number
to user space. If the syncpoint does not have an associated base, the
function returns -ENXIO.

Signed-off-by: Arto Merilainen <amerilainen@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index ecb6ec7..28e1781 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -418,6 +418,34 @@
 
 	return context->client->ops->submit(context, args, drm, file);
 }
+
+static int tegra_get_syncpt_base(struct drm_device *drm, void *data,
+				 struct drm_file *file)
+{
+	struct tegra_drm_file *fpriv = file->driver_priv;
+	struct drm_tegra_get_syncpt_base *args = data;
+	struct tegra_drm_context *context;
+	struct host1x_syncpt_base *base;
+	struct host1x_syncpt *syncpt;
+
+	context = tegra_drm_get_context(args->context);
+
+	if (!tegra_drm_file_owns_context(fpriv, context))
+		return -ENODEV;
+
+	if (args->syncpt >= context->client->base.num_syncpts)
+		return -EINVAL;
+
+	syncpt = context->client->base.syncpts[args->syncpt];
+
+	base = host1x_syncpt_get_base(syncpt);
+	if (!base)
+		return -ENXIO;
+
+	args->id = host1x_syncpt_base_id(base);
+
+	return 0;
+}
 #endif
 
 static const struct drm_ioctl_desc tegra_drm_ioctls[] = {
@@ -431,6 +459,7 @@
 	DRM_IOCTL_DEF_DRV(TEGRA_CLOSE_CHANNEL, tegra_close_channel, DRM_UNLOCKED),
 	DRM_IOCTL_DEF_DRV(TEGRA_GET_SYNCPT, tegra_get_syncpt, DRM_UNLOCKED),
 	DRM_IOCTL_DEF_DRV(TEGRA_SUBMIT, tegra_submit, DRM_UNLOCKED),
+	DRM_IOCTL_DEF_DRV(TEGRA_GET_SYNCPT_BASE, tegra_get_syncpt_base, DRM_UNLOCKED),
 #endif
 };
 
diff --git a/include/uapi/drm/tegra_drm.h b/include/uapi/drm/tegra_drm.h
index 0f8575f..5e1ab55 100644
--- a/include/uapi/drm/tegra_drm.h
+++ b/include/uapi/drm/tegra_drm.h
@@ -68,6 +68,12 @@
 	__u32 id;
 };
 
+struct drm_tegra_get_syncpt_base {
+	__u64 context;
+	__u32 syncpt;
+	__u32 id;
+};
+
 struct drm_tegra_syncpt {
 	__u32 id;
 	__u32 incrs;
@@ -118,15 +124,16 @@
 	__u32 reserved[5];	/* future expansion */
 };
 
-#define DRM_TEGRA_GEM_CREATE	0x00
-#define DRM_TEGRA_GEM_MMAP	0x01
-#define DRM_TEGRA_SYNCPT_READ	0x02
-#define DRM_TEGRA_SYNCPT_INCR	0x03
-#define DRM_TEGRA_SYNCPT_WAIT	0x04
-#define DRM_TEGRA_OPEN_CHANNEL	0x05
-#define DRM_TEGRA_CLOSE_CHANNEL	0x06
-#define DRM_TEGRA_GET_SYNCPT	0x07
-#define DRM_TEGRA_SUBMIT	0x08
+#define DRM_TEGRA_GEM_CREATE		0x00
+#define DRM_TEGRA_GEM_MMAP		0x01
+#define DRM_TEGRA_SYNCPT_READ		0x02
+#define DRM_TEGRA_SYNCPT_INCR		0x03
+#define DRM_TEGRA_SYNCPT_WAIT		0x04
+#define DRM_TEGRA_OPEN_CHANNEL		0x05
+#define DRM_TEGRA_CLOSE_CHANNEL		0x06
+#define DRM_TEGRA_GET_SYNCPT		0x07
+#define DRM_TEGRA_SUBMIT		0x08
+#define DRM_TEGRA_GET_SYNCPT_BASE	0x09
 
 #define DRM_IOCTL_TEGRA_GEM_CREATE DRM_IOWR(DRM_COMMAND_BASE + DRM_TEGRA_GEM_CREATE, struct drm_tegra_gem_create)
 #define DRM_IOCTL_TEGRA_GEM_MMAP DRM_IOWR(DRM_COMMAND_BASE + DRM_TEGRA_GEM_MMAP, struct drm_tegra_gem_mmap)
@@ -137,5 +144,6 @@
 #define DRM_IOCTL_TEGRA_CLOSE_CHANNEL DRM_IOWR(DRM_COMMAND_BASE + DRM_TEGRA_CLOSE_CHANNEL, struct drm_tegra_open_channel)
 #define DRM_IOCTL_TEGRA_GET_SYNCPT DRM_IOWR(DRM_COMMAND_BASE + DRM_TEGRA_GET_SYNCPT, struct drm_tegra_get_syncpt)
 #define DRM_IOCTL_TEGRA_SUBMIT DRM_IOWR(DRM_COMMAND_BASE + DRM_TEGRA_SUBMIT, struct drm_tegra_submit)
+#define DRM_IOCTL_TEGRA_GET_SYNCPT_BASE DRM_IOWR(DRM_COMMAND_BASE + DRM_TEGRA_GET_SYNCPT_BASE, struct drm_tegra_get_syncpt_base)
 
 #endif