tree: https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git x86/amd head: 20b46dff13bd1d250dc968b318f0fac3c996b3fa commit: 3ac3e5ee5ed56b07448f295902e44916eb6979fc [6/12] iommu/amd: Copy old trans table from old kernel config: x86_64-rhel (attached as .config) compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901 reproduce: git checkout 3ac3e5ee5ed56b07448f295902e44916eb6979fc # save the attached .config to linux build tree make ARCH=x86_64
Note: it may well be a FALSE warning. FWIW you are at least aware of it now. http://gcc.gnu.org/wiki/Better_Uninitialized_Warnings All warnings (new ones prefixed by >>): drivers//iommu/amd_iommu_init.c: In function 'early_enable_iommus': >> drivers//iommu/amd_iommu_init.c:887:17: warning: 'entry' may be used >> uninitialized in this function [-Wmaybe-uninitialized] old_devtb_phys = entry & PAGE_MASK; drivers//iommu/amd_iommu_init.c:858:6: note: 'entry' was declared here u64 entry, last_entry = 0; ^~~~~ vim +/entry +887 drivers//iommu/amd_iommu_init.c c5cca146 arch/x86/kernel/amd_iommu_init.c Joerg Roedel 2009-10-09 851 c5cca146 arch/x86/kernel/amd_iommu_init.c Joerg Roedel 2009-10-09 852 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 853 static bool copy_device_table(void) 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 854 { 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 855 struct dev_table_entry *old_devtb = NULL; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 856 u32 lo, hi, devid, old_devtb_size; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 857 phys_addr_t old_devtb_phys; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 858 u64 entry, last_entry = 0; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 859 struct amd_iommu *iommu; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 860 u16 dom_id, dte_v; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 861 gfp_t gfp_flag; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 862 3ac3e5ee drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 863 if (!amd_iommu_pre_enabled) 3ac3e5ee drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 864 return false; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 865 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 866 pr_warn("Translation is already enabled - trying to copy translation structures\n"); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 867 for_each_iommu(iommu) { 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 868 /* All IOMMUs should use the same device table with the same size */ 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 869 lo = readl(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 870 hi = readl(iommu->mmio_base + MMIO_DEV_TABLE_OFFSET + 4); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 871 entry = (((u64) hi) << 32) + lo; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 872 if (last_entry && last_entry != entry) { 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 873 pr_err("IOMMU:%d should use the same dev table as others!/n", 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 874 iommu->index); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 875 return false; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 876 } 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 877 last_entry = entry; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 878 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 879 old_devtb_size = ((entry & ~PAGE_MASK) + 1) << 12; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 880 if (old_devtb_size != dev_table_size) { 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 881 pr_err("The device table size of IOMMU:%d is not expected!/n", 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 882 iommu->index); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 883 return false; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 884 } 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 885 } 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 886 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 @887 old_devtb_phys = entry & PAGE_MASK; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 888 old_devtb = memremap(old_devtb_phys, dev_table_size, MEMREMAP_WB); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 889 if (!old_devtb) 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 890 return false; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 891 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 892 gfp_flag = GFP_KERNEL | __GFP_ZERO; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 893 old_dev_tbl_cpy = (void *)__get_free_pages(gfp_flag, 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 894 get_order(dev_table_size)); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 895 if (old_dev_tbl_cpy == NULL) { 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 896 pr_err("Failed to allocate memory for copying old device table!/n"); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 897 return false; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 898 } 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 899 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 900 for (devid = 0; devid <= amd_iommu_last_bdf; ++devid) { 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 901 old_dev_tbl_cpy[devid] = old_devtb[devid]; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 902 dom_id = old_devtb[devid].data[1] & DEV_DOMID_MASK; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 903 dte_v = old_devtb[devid].data[0] & DTE_FLAG_V; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 904 if (dte_v && dom_id) 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 905 __set_bit(dom_id, amd_iommu_pd_alloc_bitmap); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 906 } 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 907 memunmap(old_devtb); 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 908 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 909 return true; 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 910 } 45a01c42 drivers/iommu/amd_iommu_init.c Baoquan He 2017-08-09 911 :::::: The code at line 887 was first introduced by commit :::::: 45a01c42933b93e59811099f97aa4179d499a42c iommu/amd: Add function copy_dev_tables() :::::: TO: Baoquan He <b...@redhat.com> :::::: CC: Joerg Roedel <jroe...@suse.de> --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
.config.gz
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