Re: [PATCH v2 1/3] uio: introduce UIO_MEM_DMA_COHERENT type

[kernel test robot <lkp@intel.com>]

Hi Nilesh,

kernel test robot noticed the following build warnings:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on char-misc/char-misc-next char-misc/char-misc-linus linus/master v6.7-rc8 next-20240104]
[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#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Nilesh-Javali/uio-introduce-UIO_MEM_DMA_COHERENT-type/20240103-171531
base:   char-misc/char-misc-testing
patch link:    https://lore.kernel.org/r/20240103091137.27142-2-njavali%40marvell.com
patch subject: [PATCH v2 1/3] uio: introduce UIO_MEM_DMA_COHERENT type
config: arc-allmodconfig (https://download.01.org/0day-ci/archive/20240104/202401042222.J9GOUiYL-lkp@intel.com/config)
compiler: arceb-elf-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240104/202401042222.J9GOUiYL-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202401042222.J9GOUiYL-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/uio/uio.c:27:
   drivers/uio/uio.c: In function 'uio_mmap_dma_coherent':
>> drivers/uio/uio.c:789:33: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
     789 |                                 (void *)mem->addr,
         |                                 ^
   include/linux/dma-mapping.h:424:63: note: in definition of macro 'dma_mmap_coherent'
     424 | #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, 0)
         |                                                               ^


vim +789 drivers/uio/uio.c

   762	
   763	static int uio_mmap_dma_coherent(struct vm_area_struct *vma)
   764	{
   765		struct uio_device *idev = vma->vm_private_data;
   766		struct uio_mem *mem;
   767		int ret = 0;
   768		int mi;
   769	
   770		mi = uio_find_mem_index(vma);
   771		if (mi < 0)
   772			return -EINVAL;
   773	
   774		mem = idev->info->mem + mi;
   775	
   776		if (mem->dma_addr & ~PAGE_MASK)
   777			return -ENODEV;
   778		if (vma->vm_end - vma->vm_start > mem->size)
   779			return -EINVAL;
   780	
   781		/*
   782		 * UIO uses offset to index into the maps for a device.
   783		 * We need to clear vm_pgoff for dma_mmap_coherent.
   784		 */
   785		vma->vm_pgoff = 0;
   786	
   787		ret = dma_mmap_coherent(&idev->dev,
   788					vma,
 > 789					(void *)mem->addr,
   790					mem->dma_addr,
   791					vma->vm_end - vma->vm_start);
   792		vma->vm_pgoff = mi;
   793	
   794		return ret;
   795	}
   796	

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