[kbuild-all] Re: [PATCH 4/4] powerpc/pseries/iommu: Remove default DMA window before creating DDW

Hi Leonardo, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on powerpc/next] [also build test WARNING on v5.8-rc1 next-20200618] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Leonardo-Bras/Remove-default-DMA... base: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next config: powerpc-randconfig-r031-20200619 (attached as .config) compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project 63700971ac9cdf198faa4a3a7c226fa579e49206) 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 # 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 warnings (new ones prefixed by >>, old ones prefixed by <<): if (ret) ^~~ arch/powerpc/platforms/pseries/iommu.c:1234:6: note: uninitialized use occurs here if (dfl_win) ^~~~~~~ arch/powerpc/platforms/pseries/iommu.c:1111:2: note: remove the 'if' if its condition is always false if (ret) ^~~~~~~~ arch/powerpc/platforms/pseries/iommu.c:1079:34: note: initialize the variable 'dfl_win' to silence this warning struct property *win64, *dfl_win; ^ = NULL 1 warning generated. vim +1111 arch/powerpc/platforms/pseries/iommu.c 715a454e17d328 Leonardo Bras 2020-06-19 1056 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1057 /* 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1058 * If the PE supports dynamic dma windows, and there is space for a table 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1059 * that can map all pages in a linear offset, then setup such a table, 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1060 * and record the dma-offset in the struct device. 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1061 * 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1062 * dev: the pci device we are checking 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1063 * pdn: the parent pe node with the ibm,dma_window property 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1064 * Future: also check if we can remap the base window for our base page size 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1065 * 9ae2fddeda4cbf Christoph Hellwig 2019-02-13 1066 * returns the dma offset for use by the direct mapped DMA code. 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1067 */ 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1068 static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn) 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1069 { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1070 int len, ret; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1071 struct ddw_query_response query; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1072 struct ddw_create_response create; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1073 int page_shift; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1074 u64 dma_addr, max_addr; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1075 struct device_node *dn; 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1076 u32 ddw_avail[3]; 3248d5f65aac44 Leonardo Bras 2020-06-19 1077 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1078 struct direct_window *window; 3248d5f65aac44 Leonardo Bras 2020-06-19 1079 struct property *win64, *dfl_win; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1080 struct dynamic_dma_window_prop *ddwprop; 61435690a9c781 Nishanth Aravamudan 2013-03-07 1081 struct failed_ddw_pdn *fpdn; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1082 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1083 mutex_lock(&direct_window_init_mutex); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1084 b73a635f348610 Milton Miller 2011-05-11 1085 dma_addr = find_existing_ddw(pdn); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1086 if (dma_addr != 0) 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1087 goto out_unlock; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1088 61435690a9c781 Nishanth Aravamudan 2013-03-07 1089 /* 61435690a9c781 Nishanth Aravamudan 2013-03-07 1090 * If we already went through this for a previous function of 61435690a9c781 Nishanth Aravamudan 2013-03-07 1091 * the same device and failed, we don't want to muck with the 61435690a9c781 Nishanth Aravamudan 2013-03-07 1092 * DMA window again, as it will race with in-flight operations 61435690a9c781 Nishanth Aravamudan 2013-03-07 1093 * and can lead to EEHs. The above mutex protects access to the 61435690a9c781 Nishanth Aravamudan 2013-03-07 1094 * list. 61435690a9c781 Nishanth Aravamudan 2013-03-07 1095 */ 61435690a9c781 Nishanth Aravamudan 2013-03-07 1096 list_for_each_entry(fpdn, &failed_ddw_pdn_list, list) { b7c670d673d118 Rob Herring 2017-08-21 1097 if (fpdn->pdn == pdn) 61435690a9c781 Nishanth Aravamudan 2013-03-07 1098 goto out_unlock; 61435690a9c781 Nishanth Aravamudan 2013-03-07 1099 } 61435690a9c781 Nishanth Aravamudan 2013-03-07 1100 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1101 /* 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1102 * the ibm,ddw-applicable property holds the tokens for: 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1103 * ibm,query-pe-dma-window 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1104 * ibm,create-pe-dma-window 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1105 * ibm,remove-pe-dma-window 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1106 * for the given node in that order. 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1107 * the property is actually in the parent, not the PE 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1108 */ 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1109 ret = of_property_read_u32_array(pdn, "ibm,ddw-applicable", 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1110 &ddw_avail[0], 3); 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 @1111 if (ret) ae69e1eddc646f Nishanth Aravamudan 2014-01-10 1112 goto out_failed; 25ebc45b93452d Nishanth Aravamudan 2012-05-15 1113 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1114 /* 3248d5f65aac44 Leonardo Bras 2020-06-19 1115 * First step of setting up DDW is removing the default DMA window, 3248d5f65aac44 Leonardo Bras 2020-06-19 1116 * if it's present. It will make all the resources available to the 3248d5f65aac44 Leonardo Bras 2020-06-19 1117 * new DDW window. 3248d5f65aac44 Leonardo Bras 2020-06-19 1118 * If anything fails after this, we need to restore it. 3248d5f65aac44 Leonardo Bras 2020-06-19 1119 */ 3248d5f65aac44 Leonardo Bras 2020-06-19 1120 3248d5f65aac44 Leonardo Bras 2020-06-19 1121 dfl_win = of_find_property(pdn, "ibm,dma-window", NULL); 3248d5f65aac44 Leonardo Bras 2020-06-19 1122 if (dfl_win) 3248d5f65aac44 Leonardo Bras 2020-06-19 1123 remove_dma_window(pdn, ddw_avail, dfl_win); 3248d5f65aac44 Leonardo Bras 2020-06-19 1124 3248d5f65aac44 Leonardo Bras 2020-06-19 1125 /* 3248d5f65aac44 Leonardo Bras 2020-06-19 1126 * Query if there is a window of size to map the 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1127 * whole partition. Query returns number of windows, largest 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1128 * block assigned to PE (partition endpoint), and two bitmasks 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1129 * of page sizes: supported and supported for migrate-dma. 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1130 */ 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1131 dn = pci_device_to_OF_node(dev); 0ef1ee0bda323e Leonardo Bras 2020-06-19 1132 ret = query_ddw(dev, ddw_avail, &query, pdn); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1133 if (ret != 0) ae69e1eddc646f Nishanth Aravamudan 2014-01-10 1134 goto out_failed; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1135 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1136 if (query.windows_available == 0) { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1137 /* 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1138 * no additional windows are available for this device. 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1139 * We might be able to reallocate the existing window, 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1140 * trading in for a larger page size. 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1141 */ 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1142 dev_dbg(&dev->dev, "no free dynamic windows"); ae69e1eddc646f Nishanth Aravamudan 2014-01-10 1143 goto out_failed; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1144 } 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1145 if (query.page_size & 4) { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1146 page_shift = 24; /* 16MB */ 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1147 } else if (query.page_size & 2) { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1148 page_shift = 16; /* 64kB */ 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1149 } else if (query.page_size & 1) { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1150 page_shift = 12; /* 4kB */ 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1151 } else { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1152 dev_dbg(&dev->dev, "no supported direct page size in mask %x", 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1153 query.page_size); ae69e1eddc646f Nishanth Aravamudan 2014-01-10 1154 goto out_failed; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1155 } 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1156 /* verify the window * number of ptes will map the partition */ 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1157 /* check largest block * page size > max memory hotplug addr */ 68c0449ea16d77 Alexey Kardashevskiy 2018-12-19 1158 max_addr = ddw_memory_hotplug_max(); 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1159 if (query.largest_available_block < (max_addr >> page_shift)) { 0ef1ee0bda323e Leonardo Bras 2020-06-19 1160 dev_dbg(&dev->dev, "can't map partition max 0x%llx with %llu " 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1161 "%llu-sized pages\n", max_addr, query.largest_available_block, 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1162 1ULL << page_shift); ae69e1eddc646f Nishanth Aravamudan 2014-01-10 1163 goto out_failed; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1164 } 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1165 len = order_base_2(max_addr); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1166 win64 = kzalloc(sizeof(struct property), GFP_KERNEL); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1167 if (!win64) { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1168 dev_info(&dev->dev, 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1169 "couldn't allocate property for 64bit dma window\n"); ae69e1eddc646f Nishanth Aravamudan 2014-01-10 1170 goto out_failed; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1171 } 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1172 win64->name = kstrdup(DIRECT64_PROPNAME, GFP_KERNEL); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1173 win64->value = ddwprop = kmalloc(sizeof(*ddwprop), GFP_KERNEL); 767303349e052a Nishanth Aravamudan 2011-05-06 1174 win64->length = sizeof(*ddwprop); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1175 if (!win64->name || !win64->value) { 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1176 dev_info(&dev->dev, 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1177 "couldn't allocate property name and value\n"); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1178 goto out_free_prop; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1179 } 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1180 b73a635f348610 Milton Miller 2011-05-11 1181 ret = create_ddw(dev, ddw_avail, &create, page_shift, len); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1182 if (ret != 0) 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1183 goto out_free_prop; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1184 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1185 ddwprop->liobn = cpu_to_be32(create.liobn); 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1186 ddwprop->dma_base = cpu_to_be64(((u64)create.addr_hi << 32) | 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1187 create.addr_lo); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1188 ddwprop->tce_shift = cpu_to_be32(page_shift); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1189 ddwprop->window_shift = cpu_to_be32(len); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1190 b7c670d673d118 Rob Herring 2017-08-21 1191 dev_dbg(&dev->dev, "created tce table LIOBN 0x%x for %pOF\n", b7c670d673d118 Rob Herring 2017-08-21 1192 create.liobn, dn); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1193 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1194 window = kzalloc(sizeof(*window), GFP_KERNEL); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1195 if (!window) 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1196 goto out_clear_window; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1197 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1198 ret = walk_system_ram_range(0, memblock_end_of_DRAM() >> PAGE_SHIFT, 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1199 win64->value, tce_setrange_multi_pSeriesLP_walk); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1200 if (ret) { b7c670d673d118 Rob Herring 2017-08-21 1201 dev_info(&dev->dev, "failed to map direct window for %pOF: %d\n", b7c670d673d118 Rob Herring 2017-08-21 1202 dn, ret); 7a19081fc26581 Julia Lawall 2011-08-08 1203 goto out_free_window; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1204 } 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1205 79d1c712958f94 Nathan Fontenot 2012-10-02 1206 ret = of_add_property(pdn, win64); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1207 if (ret) { b7c670d673d118 Rob Herring 2017-08-21 1208 dev_err(&dev->dev, "unable to add dma window property for %pOF: %d", b7c670d673d118 Rob Herring 2017-08-21 1209 pdn, ret); 7a19081fc26581 Julia Lawall 2011-08-08 1210 goto out_free_window; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1211 } 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1212 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1213 window->device = pdn; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1214 window->prop = ddwprop; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1215 spin_lock(&direct_window_list_lock); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1216 list_add(&window->list, &direct_window_list); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1217 spin_unlock(&direct_window_list_lock); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1218 9410e0185e6539 Alexey Kardashevskiy 2014-09-25 1219 dma_addr = be64_to_cpu(ddwprop->dma_base); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1220 goto out_unlock; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1221 7a19081fc26581 Julia Lawall 2011-08-08 1222 out_free_window: 7a19081fc26581 Julia Lawall 2011-08-08 1223 kfree(window); 7a19081fc26581 Julia Lawall 2011-08-08 1224 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1225 out_clear_window: 5efbabe09d986f Gavin Shan 2014-08-11 1226 remove_ddw(pdn, true); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1227 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1228 out_free_prop: 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1229 kfree(win64->name); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1230 kfree(win64->value); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1231 kfree(win64); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1232 ae69e1eddc646f Nishanth Aravamudan 2014-01-10 1233 out_failed: 3248d5f65aac44 Leonardo Bras 2020-06-19 1234 if (dfl_win) 3248d5f65aac44 Leonardo Bras 2020-06-19 1235 reset_dma_window(dev, pdn); 25ebc45b93452d Nishanth Aravamudan 2012-05-15 1236 61435690a9c781 Nishanth Aravamudan 2013-03-07 1237 fpdn = kzalloc(sizeof(*fpdn), GFP_KERNEL); 61435690a9c781 Nishanth Aravamudan 2013-03-07 1238 if (!fpdn) 61435690a9c781 Nishanth Aravamudan 2013-03-07 1239 goto out_unlock; 61435690a9c781 Nishanth Aravamudan 2013-03-07 1240 fpdn->pdn = pdn; 61435690a9c781 Nishanth Aravamudan 2013-03-07 1241 list_add(&fpdn->list, &failed_ddw_pdn_list); 61435690a9c781 Nishanth Aravamudan 2013-03-07 1242 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1243 out_unlock: 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1244 mutex_unlock(&direct_window_init_mutex); 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1245 return dma_addr; 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1246 } 4e8b0cf46b2570 Nishanth Aravamudan 2011-02-10 1247 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org