Hi John,

I love your patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.13-rc1 next-20210510]
[cannot apply to iommu/next mkp-scsi/for-next scsi/for-next]
[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/John-Garry/dma-mapping-iommu-Allow-IOMMU-IOVA-rcache-range-to-be-configured/20210510-222805
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 6efb943b8616ec53a5e444193dccf1af9ad627b5
config: i386-randconfig-s002-20210510 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.3-341-g8af24329-dirty
        # https://github.com/0day-ci/linux/commit/d9a8e3a4ac0070cd3094af3b41e9c6277faf3ea6
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review John-Garry/dma-mapping-iommu-Allow-IOMMU-IOVA-rcache-range-to-be-configured/20210510-222805
        git checkout d9a8e3a4ac0070cd3094af3b41e9c6277faf3ea6
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' W=1 ARCH=i386 

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

All warnings (new ones prefixed by >>):

>> drivers/iommu/iova.c:50:1: warning: no previous prototype for '__init_iova_domain' [-Wmissing-prototypes]
      50 | __init_iova_domain(struct iova_domain *iovad, unsigned long granule,
         | ^~~~~~~~~~~~~~~~~~


sparse warnings: (new ones prefixed by >>)
>> drivers/iommu/iova.c:50:1: sparse: sparse: symbol '__init_iova_domain' was not declared. Should it be static?

Please review and possibly fold the followup patch.

vim +/__init_iova_domain +50 drivers/iommu/iova.c

    48	
    49	void
  > 50	__init_iova_domain(struct iova_domain *iovad, unsigned long granule,
    51		unsigned long start_pfn, unsigned long iova_len)
    52	{
    53		/*
    54		 * IOVA granularity will normally be equal to the smallest
    55		 * supported IOMMU page size; both *must* be capable of
    56		 * representing individual CPU pages exactly.
    57		 */
    58		BUG_ON((granule > PAGE_SIZE) || !is_power_of_2(granule));
    59	
    60		spin_lock_init(&iovad->iova_rbtree_lock);
    61		iovad->rbroot = RB_ROOT;
    62		iovad->cached_node = &iovad->anchor.node;
    63		iovad->cached32_node = &iovad->anchor.node;
    64		iovad->granule = granule;
    65		iovad->start_pfn = start_pfn;
    66		iovad->dma_32bit_pfn = 1UL << (32 - iova_shift(iovad));
    67		iovad->max32_alloc_size = iovad->dma_32bit_pfn;
    68		iovad->flush_cb = NULL;
    69		iovad->fq = NULL;
    70		iovad->anchor.pfn_lo = iovad->anchor.pfn_hi = IOVA_ANCHOR;
    71		rb_link_node(&iovad->anchor.node, NULL, &iovad->rbroot.rb_node);
    72		rb_insert_color(&iovad->anchor.node, &iovad->rbroot);
    73		cpuhp_state_add_instance_nocalls(CPUHP_IOMMU_IOVA_DEAD, &iovad->cpuhp_dead);
    74		init_iova_rcaches(iovad, iova_len);
    75	}
    76	

---
0-DAY CI Kernel Test Service, Intel Corporation
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