Re: [PATCH v10 16/26] cxl: define a driver interface for DPA allocation

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

Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 6cd498f39cf5e1475b567eb67a6fcf1ca3d67d46]

url:    https://github.com/intel-lab-lkp/linux/commits/alucerop-amd-com/cxl-make-memdev-creation-type-agnostic/20250205-233651
base:   6cd498f39cf5e1475b567eb67a6fcf1ca3d67d46
patch link:    https://lore.kernel.org/r/20250205151950.25268-17-alucerop%40amd.com
patch subject: [PATCH v10 16/26] cxl: define a driver interface for DPA allocation
config: i386-buildonly-randconfig-006-20250206 (https://download.01.org/0day-ci/archive/20250207/202502070213.8GNIAg8A-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250207/202502070213.8GNIAg8A-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/202502070213.8GNIAg8A-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/cxl/core/hdm.c:743: warning: Function parameter or struct member 'alloc' not described in 'cxl_request_dpa'
>> drivers/cxl/core/hdm.c:743: warning: Excess function parameter 'min' description in 'cxl_request_dpa'


vim +743 drivers/cxl/core/hdm.c

   722	
   723	/**
   724	 * cxl_request_dpa - search and reserve DPA given input constraints
   725	 * @cxlmd: memdev with an endpoint port with available decoders
   726	 * @is_ram: DPA operation mode (ram vs pmem)
   727	 * @min: the minimum amount of capacity the call needs
   728	 *
   729	 * Given that a region needs to allocate from limited HPA capacity it
   730	 * may be the case that a device has more mappable DPA capacity than
   731	 * available HPA. So, the expectation is that @min is a driver known
   732	 * value for how much capacity is needed, and @max is the limit of
   733	 * how much HPA space is available for a new region.
   734	 *
   735	 * Returns a pinned cxl_decoder with at least @min bytes of capacity
   736	 * reserved, or an error pointer. The caller is also expected to own the
   737	 * lifetime of the memdev registration associated with the endpoint to
   738	 * pin the decoder registered as well.
   739	 */
   740	struct cxl_endpoint_decoder *cxl_request_dpa(struct cxl_memdev *cxlmd,
   741						     bool is_ram,
   742						     resource_size_t alloc)
 > 743	{
   744		struct cxl_port *endpoint = cxlmd->endpoint;
   745		struct cxl_endpoint_decoder *cxled;
   746		enum cxl_partition_mode mode;
   747		struct device *cxled_dev;
   748		int rc;
   749	
   750		if (!IS_ALIGNED(alloc, SZ_256M))
   751			return ERR_PTR(-EINVAL);
   752	
   753		down_read(&cxl_dpa_rwsem);
   754		cxled_dev = device_find_child(&endpoint->dev, NULL, find_free_decoder);
   755		up_read(&cxl_dpa_rwsem);
   756	
   757		if (!cxled_dev)
   758			return ERR_PTR(-ENXIO);
   759	
   760		cxled = to_cxl_endpoint_decoder(cxled_dev);
   761	
   762		if (!cxled) {
   763			rc = -ENODEV;
   764			goto err;
   765		}
   766	
   767		if (is_ram)
   768			mode = CXL_PARTMODE_RAM;
   769		else
   770			mode = CXL_PARTMODE_PMEM;
   771	
   772		rc = cxl_dpa_set_part(cxled, mode);
   773		if (rc)
   774			goto err;
   775	
   776		rc = cxl_dpa_alloc(cxled, alloc);
   777		if (rc)
   778			goto err;
   779	
   780		return cxled;
   781	err:
   782		put_device(cxled_dev);
   783		return ERR_PTR(rc);
   784	}
   785	EXPORT_SYMBOL_NS_GPL(cxl_request_dpa, "CXL");
   786	

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