Hi Matthew,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on drm-tip/drm-tip]
[cannot apply to drm-intel/for-linux-next linus/master drm/drm-next v5.12 next-20210426]
[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/Matthew-Auld/drm-doc-rfc-i915-DG1-uAPI/20210426-174654
base:   git://anongit.freedesktop.org/drm/drm-tip drm-tip
config: i386-randconfig-s002-20210426 (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/97483a486d4dbfe124ad40b6c63265310fca3d7b
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Matthew-Auld/drm-doc-rfc-i915-DG1-uAPI/20210426-174654
        git checkout 97483a486d4dbfe124ad40b6c63265310fca3d7b
        # 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>


sparse warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/i915/gem/i915_gem_region.c:113:34: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected unsigned long long [usertype] * @@     got void [noderef] __iomem *[assigned] vaddr @@
   drivers/gpu/drm/i915/gem/i915_gem_region.c:113:34: sparse:     expected unsigned long long [usertype] *
   drivers/gpu/drm/i915/gem/i915_gem_region.c:113:34: sparse:     got void [noderef] __iomem *[assigned] vaddr

vim +113 drivers/gpu/drm/i915/gem/i915_gem_region.c

    21	
    22	int
    23	i915_gem_object_get_pages_buddy(struct drm_i915_gem_object *obj)
    24	{
    25		const u64 max_segment = i915_sg_segment_size();
    26		struct intel_memory_region *mem = obj->mm.region;
    27		struct list_head *blocks = &obj->mm.blocks;
    28		resource_size_t size = obj->base.size;
    29		resource_size_t prev_end;
    30		struct i915_buddy_block *block;
    31		unsigned int flags;
    32		struct sg_table *st;
    33		struct scatterlist *sg;
    34		unsigned int sg_page_sizes;
    35		int ret;
    36	
    37		st = kmalloc(sizeof(*st), GFP_KERNEL);
    38		if (!st)
    39			return -ENOMEM;
    40	
    41		if (sg_alloc_table(st, size >> PAGE_SHIFT, GFP_KERNEL)) {
    42			kfree(st);
    43			return -ENOMEM;
    44		}
    45	
    46		flags = I915_ALLOC_MIN_PAGE_SIZE;
    47		if (obj->flags & I915_BO_ALLOC_CONTIGUOUS)
    48			flags |= I915_ALLOC_CONTIGUOUS;
    49	
    50		ret = __intel_memory_region_get_pages_buddy(mem, size, flags, blocks);
    51		if (ret)
    52			goto err_free_sg;
    53	
    54		GEM_BUG_ON(list_empty(blocks));
    55	
    56		sg = st->sgl;
    57		st->nents = 0;
    58		sg_page_sizes = 0;
    59		prev_end = (resource_size_t)-1;
    60	
    61		list_for_each_entry(block, blocks, link) {
    62			u64 block_size, offset;
    63	
    64			block_size = min_t(u64, size,
    65					   i915_buddy_block_size(&mem->mm, block));
    66			offset = i915_buddy_block_offset(block);
    67	
    68			while (block_size) {
    69				u64 len;
    70	
    71				if (offset != prev_end || sg->length >= max_segment) {
    72					if (st->nents) {
    73						sg_page_sizes |= sg->length;
    74						sg = __sg_next(sg);
    75					}
    76	
    77					sg_dma_address(sg) = mem->region.start + offset;
    78					sg_dma_len(sg) = 0;
    79					sg->length = 0;
    80					st->nents++;
    81				}
    82	
    83				len = min(block_size, max_segment - sg->length);
    84				sg->length += len;
    85				sg_dma_len(sg) += len;
    86	
    87				offset += len;
    88				block_size -= len;
    89	
    90				prev_end = offset;
    91			}
    92		}
    93	
    94		sg_page_sizes |= sg->length;
    95		sg_mark_end(sg);
    96		i915_sg_trim(st);
    97	
    98		/* Intended for kernel internal use only */
    99		if (obj->flags & I915_BO_ALLOC_CPU_CLEAR) {
   100			struct scatterlist *sg;
   101			unsigned long i;
   102	
   103			for_each_sg(st->sgl, sg, st->nents, i) {
   104				unsigned int length;
   105				void __iomem *vaddr;
   106				dma_addr_t daddr;
   107	
   108				daddr = sg_dma_address(sg);
   109				daddr -= mem->region.start;
   110				length = sg_dma_len(sg);
   111	
   112				vaddr = io_mapping_map_wc(&mem->iomap, daddr, length);
 > 113				memset64(vaddr, 0, length / sizeof(u64));
   114				io_mapping_unmap(vaddr);
   115			}
   116	
   117			wmb();
   118		}
   119	
   120		__i915_gem_object_set_pages(obj, st, sg_page_sizes);
   121	
   122		return 0;
   123	
   124	err_free_sg:
   125		sg_free_table(st);
   126		kfree(st);
   127		return ret;
   128	}
   129	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org