[PATCH v2] misc: sram: Add DMA-BUF Heap exporting of SRAM areas

[kernel test robot]

Hi Andrew,

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 soc/for-next pza/reset/next linus/master v6.3-rc5 next-20230403]
[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/misc-sram-Add-DMA-BUF-Heap-exporting-of-SRAM-areas/20230404-032607
patch link:    https://lore.kernel.org/r/20230403192433.26648-1-afd%40ti.com
patch subject: [PATCH v2] misc: sram: Add DMA-BUF Heap exporting of SRAM areas
config: loongarch-allyesconfig (https://download.01.org/0day-ci/archive/20230404/202304041144.t5JCOGsE-lkp@intel.com/config)
compiler: loongarch64-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/6fcaa3c7cfbc144dd982f9abaa1c5af50dde24a8
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Andrew-Davis/misc-sram-Add-DMA-BUF-Heap-exporting-of-SRAM-areas/20230404-032607
        git checkout 6fcaa3c7cfbc144dd982f9abaa1c5af50dde24a8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash drivers/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp at intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202304041144.t5JCOGsE-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/misc/sram-dma-heap.c:161:17: warning: no previous prototype for 'sram_dma_heap_allocate' [-Wmissing-prototypes]
     161 | struct dma_buf *sram_dma_heap_allocate(struct dma_heap *heap,
         |                 ^~~~~~~~~~~~~~~~~~~~~~


vim +/sram_dma_heap_allocate +161 drivers/misc/sram-dma-heap.c

   160	
 > 161	struct dma_buf *sram_dma_heap_allocate(struct dma_heap *heap,
   162					       unsigned long len,
   163					       unsigned long fd_flags,
   164					       unsigned long heap_flags)
   165	{
   166		struct sram_dma_heap *sram_dma_heap = dma_heap_get_drvdata(heap);
   167		struct sram_dma_heap_buffer *buffer;
   168	
   169		DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
   170		struct dma_buf *dmabuf;
   171		int ret;
   172	
   173		buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
   174		if (!buffer)
   175			return ERR_PTR(-ENOMEM);
   176		buffer->pool = sram_dma_heap->pool;
   177		INIT_LIST_HEAD(&buffer->attachments);
   178		mutex_init(&buffer->attachments_lock);
   179		buffer->len = len;
   180	
   181		buffer->vaddr = (void *)gen_pool_alloc(buffer->pool, buffer->len);
   182		if (!buffer->vaddr) {
   183			ret = -ENOMEM;
   184			goto free_buffer;
   185		}
   186	
   187		buffer->paddr = gen_pool_virt_to_phys(buffer->pool, (unsigned long)buffer->vaddr);
   188		if (buffer->paddr == -1) {
   189			ret = -ENOMEM;
   190			goto free_pool;
   191		}
   192	
   193		/* create the dmabuf */
   194		exp_info.exp_name = dma_heap_get_name(heap);
   195		exp_info.ops = &sram_dma_heap_buf_ops;
   196		exp_info.size = buffer->len;
   197		exp_info.flags = fd_flags;
   198		exp_info.priv = buffer;
   199		dmabuf = dma_buf_export(&exp_info);
   200		if (IS_ERR(dmabuf)) {
   201			ret = PTR_ERR(dmabuf);
   202			goto free_pool;
   203		}
   204	
   205		return dmabuf;
   206	
   207	free_pool:
   208		gen_pool_free(buffer->pool, (unsigned long)buffer->vaddr, buffer->len);
   209	free_buffer:
   210		kfree(buffer);
   211	
   212		return ERR_PTR(ret);
   213	}
   214	

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