[PATCH] dma-buf: cma_heap: Check for device max segment size when attaching

[Andrew Davis]

On 8/22/22 7:45 PM, kernel test robot wrote:
> Hi Andrew,
> 
> Thank you for the patch! Perhaps something to improve:
> 
> [auto build test WARNING on drm-misc/drm-misc-next]
> [also build test WARNING on linus/master v6.0-rc2 next-20220822]
> [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/Andrew-Davis/dma-buf-cma_heap-Check-for-device-max-segment-size-when-attaching/20220823-073240
> base:   git://anongit.freedesktop.org/drm/drm-misc drm-misc-next
> config: s390-allyesconfig (https://download.01.org/0day-ci/archive/20220823/202208230840.npLcmvVn-lkp@intel.com/config)
> compiler: s390-linux-gcc (GCC) 12.1.0
> 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/intel-lab-lkp/linux/commit/f390cef50ba6681ea767283e413cb8e9f8f2b426
>          git remote add linux-review https://github.com/intel-lab-lkp/linux
>          git fetch --no-tags linux-review Andrew-Davis/dma-buf-cma_heap-Check-for-device-max-segment-size-when-attaching/20220823-073240
>          git checkout f390cef50ba6681ea767283e413cb8e9f8f2b426
>          # save the config file
>          mkdir build_dir && cp config build_dir/.config
>          COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/dma-buf/
> 
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp at intel.com>
> 
> All warnings (new ones prefixed by >>):
> 
>     drivers/dma-buf/heaps/cma_heap.c: In function 'cma_heap_attach':
>>> drivers/dma-buf/heaps/cma_heap.c:61:9: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement]


Hmm, thought someone removed this warning after we switched to C11, maybe it
is time again for some brave soul to re-poke that topic..

Not sure why I missed it when compiling though, will fix for v2.

Andrew


>        61 |         size_t max_segment = dma_get_max_seg_size(attachment->dev);
>           |         ^~~~~~
> 
> 
> vim +61 drivers/dma-buf/heaps/cma_heap.c
> 
>      49	
>      50	static int cma_heap_attach(struct dma_buf *dmabuf,
>      51				   struct dma_buf_attachment *attachment)
>      52	{
>      53		struct cma_heap_buffer *buffer = dmabuf->priv;
>      54		struct dma_heap_attachment *a;
>      55		int ret;
>      56	
>      57		a = kzalloc(sizeof(*a), GFP_KERNEL);
>      58		if (!a)
>      59			return -ENOMEM;
>      60	
>    > 61		size_t max_segment = dma_get_max_seg_size(attachment->dev);
>      62		ret = sg_alloc_table_from_pages_segment(&a->table, buffer->pages,
>      63							buffer->pagecount, 0,
>      64							buffer->pagecount << PAGE_SHIFT,
>      65							max_segment, GFP_KERNEL);
>      66		if (ret) {
>      67			kfree(a);
>      68			return ret;
>      69		}
>      70	
>      71		a->dev = attachment->dev;
>      72		INIT_LIST_HEAD(&a->list);
>      73		a->mapped = false;
>      74	
>      75		attachment->priv = a;
>      76	
>      77		mutex_lock(&buffer->lock);
>      78		list_add(&a->list, &buffer->attachments);
>      79		mutex_unlock(&buffer->lock);
>      80	
>      81		return 0;
>      82	}
>      83	
>