[alibaba-cloud:linux-next 6559/9999] drivers/virtio/virtio_balloon.c:163:5: warning: no previous prototype for 'virtballoon_free_page_report'

[alibaba-cloud:linux-next 6559/9999] drivers/virtio/virtio_balloon.c:163:5: warning: no previous prototype for 'virtballoon_free_page_report'

[kernel test robot]

tree:   https://github.com/alibaba/cloud-kernel.git linux-next
head:   d121e0c25d1a19485d7f293b67901462bb1a6552
commit: 671b4f344c85141b26aefca5aa012a58e8f729d1 [6559/9999] virtio-balloon: add support for providing free page reports to host
config: x86_64-randconfig-a015 (https://download.01.org/0day-ci/archive/20230322/202303220017.b1jaicBC-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/alibaba/cloud-kernel/commit/671b4f344c85141b26aefca5aa012a58e8f729d1
        git remote add alibaba-cloud https://github.com/alibaba/cloud-kernel.git
        git fetch --no-tags alibaba-cloud linux-next
        git checkout 671b4f344c85141b26aefca5aa012a58e8f729d1
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=x86_64 olddefconfig
        make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/infiniband/core/ drivers/virtio/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303220017.b1jaicBC-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/virtio/virtio_balloon.c:163:5: warning: no previous prototype for 'virtballoon_free_page_report' [-Wmissing-prototypes]
     163 | int virtballoon_free_page_report(struct page_reporting_dev_info *pr_dev_info,
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/virtballoon_free_page_report +163 drivers/virtio/virtio_balloon.c

   162	
 > 163	int virtballoon_free_page_report(struct page_reporting_dev_info *pr_dev_info,
   164					   struct scatterlist *sg, unsigned int nents)
   165	{
   166		struct virtio_balloon *vb =
   167			container_of(pr_dev_info, struct virtio_balloon, pr_dev_info);
   168		struct virtqueue *vq = vb->reporting_vq;
   169		unsigned int unused, err;
   170	
   171		/* We should always be able to add these buffers to an empty queue. */
   172		err = virtqueue_add_inbuf(vq, sg, nents, vb, GFP_NOWAIT | __GFP_NOWARN);
   173	
   174		/*
   175		 * In the extremely unlikely case that something has occurred and we
   176		 * are able to trigger an error we will simply display a warning
   177		 * and exit without actually processing the pages.
   178		 */
   179		if (WARN_ON_ONCE(err))
   180			return err;
   181	
   182		virtqueue_kick(vq);
   183	
   184		/* When host has read buffer, this completes via balloon_ack */
   185		wait_event(vb->acked, virtqueue_get_buf(vq, &unused));
   186	
   187		return 0;
   188	}
   189	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests