Re: [PATCH] powerpc/cpu: nr_cpu_ids should be aligned on threads_per_core

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

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Hi Pingfan,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.17-rc5 next-20180511]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Pingfan-Liu/powerpc-cpu-nr_cpu_ids-should-be-aligned-on-threads_per_core/20180514-141629
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-allnoconfig (attached as .config)
compiler: powerpc-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

   arch/powerpc/kernel/prom.c: In function 'early_init_dt_scan_cpus':
>> arch/powerpc/kernel/prom.c:370:14: error: lvalue required as left operand of assignment
      nr_cpu_ids = nr_cpus_aligned;
                 ^

vim +370 arch/powerpc/kernel/prom.c

   306	
   307	static int __init early_init_dt_scan_cpus(unsigned long node,
   308						  const char *uname, int depth,
   309						  void *data)
   310	{
   311		const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
   312		const __be32 *prop;
   313		const __be32 *intserv;
   314		int i, nthreads;
   315		int len;
   316		int found = -1;
   317		int found_thread = 0;
   318		unsigned int nr_cpus_aligned;
   319	
   320		/* We are scanning "cpu" nodes only */
   321		if (type == NULL || strcmp(type, "cpu") != 0)
   322			return 0;
   323	
   324		/* Get physical cpuid */
   325		intserv = of_get_flat_dt_prop(node, "ibm,ppc-interrupt-server#s", &len);
   326		if (!intserv)
   327			intserv = of_get_flat_dt_prop(node, "reg", &len);
   328	
   329		nthreads = len / sizeof(int);
   330	
   331		/*
   332		 * Now see if any of these threads match our boot cpu.
   333		 * NOTE: This must match the parsing done in smp_setup_cpu_maps.
   334		 */
   335		for (i = 0; i < nthreads; i++) {
   336			/*
   337			 * version 2 of the kexec param format adds the phys cpuid of
   338			 * booted proc.
   339			 */
   340			if (fdt_version(initial_boot_params) >= 2) {
   341				if (be32_to_cpu(intserv[i]) ==
   342				    fdt_boot_cpuid_phys(initial_boot_params)) {
   343					found = boot_cpu_count;
   344					found_thread = i;
   345				}
   346			} else {
   347				/*
   348				 * Check if it's the boot-cpu, set it's hw index now,
   349				 * unfortunately this format did not support booting
   350				 * off secondary threads.
   351				 */
   352				if (of_get_flat_dt_prop(node,
   353						"linux,boot-cpu", NULL) != NULL)
   354					found = boot_cpu_count;
   355			}
   356	#ifdef CONFIG_SMP
   357			/* logical cpu id is always 0 on UP kernels */
   358			boot_cpu_count++;
   359	#endif
   360		}
   361	
   362		/* Not the boot CPU */
   363		if (found < 0)
   364			return 0;
   365		/* to work around p8 subcore mode */
   366		nr_cpus_aligned = _ALIGN_UP(nr_cpu_ids, nthreads);
   367		if (nr_cpus_aligned != nr_cpu_ids) {
   368			pr_info("nr_cpus is forced to align up on threads_per_core,"
   369				"from %u to %u\n", nr_cpu_ids, nr_cpus_aligned);
 > 370			nr_cpu_ids = nr_cpus_aligned;
   371		}
   372		DBG("boot cpu: logical %d physical %d\n", found,
   373		    be32_to_cpu(intserv[found_thread]));
   374		boot_cpuid = found;
   375	
   376		/*
   377		 * PAPR defines "logical" PVR values for cpus that
   378		 * meet various levels of the architecture:
   379		 * 0x0f000001	Architecture version 2.04
   380		 * 0x0f000002	Architecture version 2.05
   381		 * If the cpu-version property in the cpu node contains
   382		 * such a value, we call identify_cpu again with the
   383		 * logical PVR value in order to use the cpu feature
   384		 * bits appropriate for the architecture level.
   385		 *
   386		 * A POWER6 partition in "POWER6 architected" mode
   387		 * uses the 0x0f000002 PVR value; in POWER5+ mode
   388		 * it uses 0x0f000001.
   389		 *
   390		 * If we're using device tree CPU feature discovery then we don't
   391		 * support the cpu-version property, and it's the responsibility of the
   392		 * firmware/hypervisor to provide the correct feature set for the
   393		 * architecture level via the ibm,powerpc-cpu-features binding.
   394		 */
   395		if (!dt_cpu_ftrs_in_use()) {
   396			prop = of_get_flat_dt_prop(node, "cpu-version", NULL);
   397			if (prop && (be32_to_cpup(prop) & 0xff000000) == 0x0f000000)
   398				identify_cpu(0, be32_to_cpup(prop));
   399	
   400			check_cpu_feature_properties(node);
   401			check_cpu_pa_features(node);
   402		}
   403	
   404		identical_pvr_fixup(node);
   405		init_mmu_slb_size(node);
   406	

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0-DAY kernel test infrastructure                Open Source Technology Center
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