tree:   https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git pending
head:   fa809cc6feedcd2575b63def7135dfaf066266bb
commit: 5885b71419e9e23ff7d404f9c8a8a5c23d42f106 [34/38] tools/testing/cxl: Introduce a mocked-up CXL port hierarchy
config: x86_64-randconfig-a011-20210814 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 1f7b25ea76a925aca690da28de9d78db7ca99d0c)
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://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git/commit/?id=5885b71419e9e23ff7d404f9c8a8a5c23d42f106
        git remote add cxl-cxl https://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl.git
        git fetch --no-tags cxl-cxl pending
        git checkout 5885b71419e9e23ff7d404f9c8a8a5c23d42f106
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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/cxl/acpi.c:185:12: warning: no previous prototype for function 'match_add_root_ports' [-Wmissing-prototypes]
   __weak int match_add_root_ports(struct pci_dev *pdev, void *data)
              ^
   drivers/cxl/acpi.c:185:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __weak int match_add_root_ports(struct pci_dev *pdev, void *data)
          ^
          static 
>> drivers/cxl/acpi.c:236:28: warning: no previous prototype for function 'to_cxl_host_bridge' [-Wmissing-prototypes]
   __weak struct acpi_device *to_cxl_host_bridge(struct device *host,
                              ^
   drivers/cxl/acpi.c:236:8: note: declare 'static' if the function is not intended to be used outside of this translation unit
   __weak struct acpi_device *to_cxl_host_bridge(struct device *host,
          ^
          static 
   2 warnings generated.


vim +/match_add_root_ports +185 drivers/cxl/acpi.c

   184	
 > 185	__weak int match_add_root_ports(struct pci_dev *pdev, void *data)
   186	{
   187		struct cxl_walk_context *ctx = data;
   188		struct pci_bus *root_bus = ctx->root;
   189		struct cxl_port *port = ctx->port;
   190		int type = pci_pcie_type(pdev);
   191		struct device *dev = ctx->dev;
   192		u32 lnkcap, port_num;
   193		int rc;
   194	
   195		if (pdev->bus != root_bus)
   196			return 0;
   197		if (!pci_is_pcie(pdev))
   198			return 0;
   199		if (type != PCI_EXP_TYPE_ROOT_PORT)
   200			return 0;
   201		if (pci_read_config_dword(pdev, pci_pcie_cap(pdev) + PCI_EXP_LNKCAP,
   202					  &lnkcap) != PCIBIOS_SUCCESSFUL)
   203			return 0;
   204	
   205		/* TODO walk DVSEC to find component register base */
   206		port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
   207		rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE);
   208		if (rc) {
   209			dev_err(dev, "failed to add dport: %s (%d)\n",
   210				dev_name(&pdev->dev), rc);
   211			ctx->error = rc;
   212			return rc;
   213		}
   214		ctx->count++;
   215	
   216		dev_dbg(dev, "add dport%d: %s\n", port_num, dev_name(&pdev->dev));
   217	
   218		return 0;
   219	}
   220	
   221	static struct cxl_dport *find_dport_by_dev(struct cxl_port *port, struct device *dev)
   222	{
   223		struct cxl_dport *dport;
   224	
   225		device_lock(&port->dev);
   226		list_for_each_entry(dport, &port->dports, list)
   227			if (dport->dport == dev) {
   228				device_unlock(&port->dev);
   229				return dport;
   230			}
   231	
   232		device_unlock(&port->dev);
   233		return NULL;
   234	}
   235	
 > 236	__weak struct acpi_device *to_cxl_host_bridge(struct device *host,
   237						      struct device *dev)
   238	{
   239		struct acpi_device *adev = to_acpi_device(dev);
   240	
   241		if (strcmp(acpi_device_hid(adev), "ACPI0016") == 0) {
   242			dev_dbg(host, "found host bridge %s\n", dev_name(&adev->dev));
   243			return adev;
   244		}
   245		return NULL;
   246	}
   247	

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