tree: git://git.infradead.org/users/hch/misc.git swiotlb-struct head: 2ca1328f0363ec245db5b5168ea393b1abd16688 commit: b9c42fcd034caf404312d0b2f42465654fbe6a2f [19/20] swiotlb: Add io_tlb_mem struct config: powerpc-randconfig-r036-20210208 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476) 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 # install powerpc cross compiling tool for clang build # apt-get install binutils-powerpc-linux-gnu git remote add hch-misc git://git.infradead.org/users/hch/misc.git git fetch --no-tags hch-misc swiotlb-struct git checkout b9c42fcd034caf404312d0b2f42465654fbe6a2f # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): if (io_tlb_start) ^~~~~~~~~~~~ io_tlb_nslabs arch/powerpc/platforms/pseries/svm.c:47:23: note: 'io_tlb_nslabs' declared here unsigned long bytes, io_tlb_nslabs; ^ 1 error generated. vim +58 arch/powerpc/platforms/pseries/svm.c 2efbc58f157a39 Anshuman Khandual 2019-08-19 38 eae9eec476d13f Thiago Jung Bauermann 2020-08-18 39 /* eae9eec476d13f Thiago Jung Bauermann 2020-08-18 40 * Initialize SWIOTLB. Essentially the same as swiotlb_init(), except that it eae9eec476d13f Thiago Jung Bauermann 2020-08-18 41 * can allocate the buffer anywhere in memory. Since the hypervisor doesn't have eae9eec476d13f Thiago Jung Bauermann 2020-08-18 42 * any addressing limitation, we don't need to allocate it in low addresses. eae9eec476d13f Thiago Jung Bauermann 2020-08-18 43 */ eae9eec476d13f Thiago Jung Bauermann 2020-08-18 44 void __init svm_swiotlb_init(void) eae9eec476d13f Thiago Jung Bauermann 2020-08-18 45 { eae9eec476d13f Thiago Jung Bauermann 2020-08-18 46 unsigned char *vstart; eae9eec476d13f Thiago Jung Bauermann 2020-08-18 47 unsigned long bytes, io_tlb_nslabs; eae9eec476d13f Thiago Jung Bauermann 2020-08-18 48 eae9eec476d13f Thiago Jung Bauermann 2020-08-18 49 io_tlb_nslabs = (swiotlb_size_or_default() >> IO_TLB_SHIFT); eae9eec476d13f Thiago Jung Bauermann 2020-08-18 50 io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); eae9eec476d13f Thiago Jung Bauermann 2020-08-18 51 eae9eec476d13f Thiago Jung Bauermann 2020-08-18 52 bytes = io_tlb_nslabs << IO_TLB_SHIFT; eae9eec476d13f Thiago Jung Bauermann 2020-08-18 53 eae9eec476d13f Thiago Jung Bauermann 2020-08-18 54 vstart = memblock_alloc(PAGE_ALIGN(bytes), PAGE_SIZE); eae9eec476d13f Thiago Jung Bauermann 2020-08-18 55 if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, false)) eae9eec476d13f Thiago Jung Bauermann 2020-08-18 56 return; eae9eec476d13f Thiago Jung Bauermann 2020-08-18 57 eae9eec476d13f Thiago Jung Bauermann 2020-08-18 @58 if (io_tlb_start) 5c8e6fff0b828a Christoph Hellwig 2021-02-05 59 memblock_free_early(__pa(vstart), eae9eec476d13f Thiago Jung Bauermann 2020-08-18 60 PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT)); eae9eec476d13f Thiago Jung Bauermann 2020-08-18 61 panic("SVM: Cannot allocate SWIOTLB buffer"); eae9eec476d13f Thiago Jung Bauermann 2020-08-18 62 } eae9eec476d13f Thiago Jung Bauermann 2020-08-18 63 :::::: The code at line 58 was first introduced by commit :::::: eae9eec476d13fad9af6da1f44a054ee02b7b161 powerpc/pseries/svm: Allocate SWIOTLB buffer anywhere in memory :::::: TO: Thiago Jung Bauermann <bauerman(a)linux.ibm.com&gt; :::::: CC: Michael Ellerman <mpe(a)ellerman.id.au&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org