drm/virtio: track whether or not a context has been initiated

Use an boolean variable to track whether a context has been
initiated.

v5: Fix possible race and sleep via mutex (olv)

Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20200225000800.2966-3-gurchetansingh@chromium.org
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index 72c1d9b..76b7b7c 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -209,6 +209,8 @@ struct virtio_gpu_device {
 
 struct virtio_gpu_fpriv {
        uint32_t ctx_id;
+       bool context_created;
+       struct mutex context_lock;
 };
 
 /* virtio_ioctl.c */

diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 00ef9fd..ec38cf5 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -40,10 +40,18 @@ void virtio_gpu_create_context(struct drm_device *dev,
        struct virtio_gpu_fpriv *vfpriv = file->driver_priv;
        char dbgname[TASK_COMM_LEN];
 
+       mutex_lock(&vfpriv->context_lock);
+       if (vfpriv->context_created)
+               goto out_unlock;
+
        get_task_comm(dbgname, current);
        virtio_gpu_cmd_context_create(vgdev, vfpriv->ctx_id,
                                      strlen(dbgname), dbgname);
        virtio_gpu_notify(vgdev);
+       vfpriv->context_created = true;
+
+out_unlock:
+       mutex_unlock(&vfpriv->context_lock);
 }
 
 static int virtio_gpu_map_ioctl(struct drm_device *dev, void *data,

diff --git a/drivers/gpu/drm/virtio/virtgpu_kms.c b/drivers/gpu/drm/virtio/virtgpu_kms.c
index f7e3712..424729c 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_kms.c
+++ b/drivers/gpu/drm/virtio/virtgpu_kms.c
@@ -258,6 +258,8 @@ int virtio_gpu_driver_open(struct drm_device *dev, struct drm_file *file)
        if (!vfpriv)
                return -ENOMEM;
 
+       mutex_init(&vfpriv->context_lock);
+
        handle = ida_alloc(&vgdev->ctx_id_ida, GFP_KERNEL);
        if (handle < 0) {
                kfree(vfpriv);
@@ -281,6 +283,7 @@ void virtio_gpu_driver_postclose(struct drm_device *dev, struct drm_file *file)
        vfpriv = file->driver_priv;
 
        virtio_gpu_context_destroy(vgdev, vfpriv->ctx_id);
+       mutex_destroy(&vfpriv->context_lock);
        kfree(vfpriv);
        file->driver_priv = NULL;
 }