Re: [PATCH] virtio-mmio: harden interrupt

[kernel test robot]

Hi Jason,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.16-rc2 next-20211125]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Jason-Wang/virtio-mmio-harden-interrupt/20211125-143334
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 5f53fa508db098c9d372423a6dac31c8a5679cdf
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20211125/202111251934.ybhaqyh7-lkp@xxxxxxxxx/config)
compiler: m68k-linux-gcc (GCC) 11.2.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/e19a8a1a95bd891090863b2d6828b8dc55d3633f
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Jason-Wang/virtio-mmio-harden-interrupt/20211125-143334
        git checkout e19a8a1a95bd891090863b2d6828b8dc55d3633f
        # save the config file to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=m68k 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> drivers/virtio/virtio_mmio.c:105:6: warning: no previous prototype for 'vm_disable_cbs' [-Wmissing-prototypes]
     105 | void vm_disable_cbs(struct virtio_device *vdev)
         |      ^~~~~~~~~~~~~~
>> drivers/virtio/virtio_mmio.c:121:6: warning: no previous prototype for 'vm_enable_cbs' [-Wmissing-prototypes]
     121 | void vm_enable_cbs(struct virtio_device *vdev)
         |      ^~~~~~~~~~~~~


vim +/vm_disable_cbs +105 drivers/virtio/virtio_mmio.c

   103	
   104	/* disable irq handlers */
 > 105	void vm_disable_cbs(struct virtio_device *vdev)
   106	{
   107		struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
   108		int irq = platform_get_irq(vm_dev->pdev, 0);
   109	
   110		/*
   111		 * The below synchronize() guarantees that any
   112		 * interrupt for this line arriving after
   113		 * synchronize_irq() has completed is guaranteed to see
   114		 * intx_soft_enabled == false.
   115		 */
   116		WRITE_ONCE(vm_dev->intr_soft_enabled, false);
   117		synchronize_irq(irq);
   118	}
   119	
   120	/* enable irq handlers */
 > 121	void vm_enable_cbs(struct virtio_device *vdev)
   122	{
   123		struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
   124		int irq = platform_get_irq(vm_dev->pdev, 0);
   125	
   126		disable_irq(irq);
   127		/*
   128		 * The above disable_irq() provides TSO ordering and
   129		 * as such promotes the below store to store-release.
   130		 */
   131		WRITE_ONCE(vm_dev->intr_soft_enabled, true);
   132		enable_irq(irq);
   133		return;
   134	}
   135	

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0-DAY CI Kernel Test Service, Intel Corporation
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