tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: 136057256686de39cc3a07c2e39ef6bc43003ff6 commit: dee2b702bcf067d7b6b62c18bdd060ff0810a800 kconfig: Add support for -Wimplicit-fallthrough date: 8 days ago config: mips-randconfig-r016-20211116 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project fbe72e41b99dc7994daac300d208a955be3e4a0a) 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 mips cross compiling tool for clang build # apt-get install binutils-mips-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit... git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout dee2b702bcf067d7b6b62c18bdd060ff0810a800 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 ARCH=mips 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 >>): case CPU_CAVIUM_OCTEON: ^ arch/mips/mm/tlbex.c:2243:3: note: insert 'break;' to avoid fall-through case CPU_CAVIUM_OCTEON: ^ break; arch/mips/mm/tlbex.c:2602:6: warning: no previous prototype for function 'build_tlb_refill_handler' [-Wmissing-prototypes] void build_tlb_refill_handler(void) ^ arch/mips/mm/tlbex.c:2602:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void build_tlb_refill_handler(void) ^ static arch/mips/mm/tlbex.c:185:1: warning: unused function 'uasm_l_second_part' [-Wunused-function] UASM_L_LA(_second_part) ^ arch/mips/include/asm/uasm.h:205:20: note: expanded from macro 'UASM_L_LA' static inline void uasm_l##lb(struct uasm_label **lab, u32 *addr) \ ^ <scratch space>:164:1: note: expanded from here uasm_l_second_part ^ arch/mips/mm/tlbex.c:197:1: warning: unused function 'uasm_l_r3000_write_probe_fail' [-Wunused-function] UASM_L_LA(_r3000_write_probe_fail) ^ arch/mips/include/asm/uasm.h:205:20: note: expanded from macro 'UASM_L_LA' static inline void uasm_l##lb(struct uasm_label **lab, u32 *addr) \ ^ <scratch space>:186:1: note: expanded from here uasm_l_r3000_write_probe_fail ^ 4 warnings generated. vim +2243 arch/mips/mm/tlbex.c ^1da177e4c3f41 Linus Torvalds 2005-04-16 2107 078a55fc824c16 Paul Gortmaker 2013-06-18 2108 static void build_r4000_tlb_load_handler(void) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2109 { 2c0e57eaef3c2b Paul Burton 2016-11-07 2110 u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl); e30ec4525d4731 Thiemo Seufer 2008-01-28 2111 struct uasm_label *l = labels; e30ec4525d4731 Thiemo Seufer 2008-01-28 2112 struct uasm_reloc *r = relocs; bf28607fbe529e David Daney 2011-07-05 2113 struct work_registers wr; ^1da177e4c3f41 Linus Torvalds 2005-04-16 2114 4bcb4ad6634ea1 Paul Burton 2018-08-10 2115 memset(p, 0, handle_tlbl_end - (char *)p); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2116 memset(labels, 0, sizeof(labels)); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2117 memset(relocs, 0, sizeof(relocs)); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2118 ^1da177e4c3f41 Linus Torvalds 2005-04-16 2119 if (bcm1250_m3_war()) { 3d45285dd1ff4d Ralf Baechle 2010-03-23 2120 unsigned int segbits = 44; 3d45285dd1ff4d Ralf Baechle 2010-03-23 2121 3d45285dd1ff4d Ralf Baechle 2010-03-23 2122 uasm_i_dmfc0(&p, K0, C0_BADVADDR); 3d45285dd1ff4d Ralf Baechle 2010-03-23 2123 uasm_i_dmfc0(&p, K1, C0_ENTRYHI); e30ec4525d4731 Thiemo Seufer 2008-01-28 2124 uasm_i_xor(&p, K0, K0, K1); 3be6022c27ace1 David Daney 2010-04-28 2125 uasm_i_dsrl_safe(&p, K1, K0, 62); 3be6022c27ace1 David Daney 2010-04-28 2126 uasm_i_dsrl_safe(&p, K0, K0, 12 + 1); 3be6022c27ace1 David Daney 2010-04-28 2127 uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits); 3d45285dd1ff4d Ralf Baechle 2010-03-23 2128 uasm_i_or(&p, K0, K0, K1); e30ec4525d4731 Thiemo Seufer 2008-01-28 2129 uasm_il_bnez(&p, &r, K0, label_leave); e30ec4525d4731 Thiemo Seufer 2008-01-28 2130 /* No need for uasm_i_nop */ ^1da177e4c3f41 Linus Torvalds 2005-04-16 2131 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 2132 bf28607fbe529e David Daney 2011-07-05 2133 wr = build_r4000_tlbchange_handler_head(&p, &l, &r); bf28607fbe529e David Daney 2011-07-05 2134 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl); 8df5beac2aa15b Maciej W. Rozycki 2006-08-23 2135 if (m4kc_tlbp_war()) 8df5beac2aa15b Maciej W. Rozycki 2006-08-23 2136 build_tlb_probe_entry(&p); 6dd9344cfc41bc David Daney 2010-02-10 2137 5890f70f15c52d Leonid Yegoshin 2014-07-15 2138 if (cpu_has_rixi && !cpu_has_rixiex) { 6dd9344cfc41bc David Daney 2010-02-10 2139 /* 6dd9344cfc41bc David Daney 2010-02-10 2140 * If the page is not _PAGE_VALID, RI or XI could not 6dd9344cfc41bc David Daney 2010-02-10 2141 * have triggered it. Skip the expensive test.. 6dd9344cfc41bc David Daney 2010-02-10 2142 */ cc33ae43797541 David Daney 2010-12-20 2143 if (use_bbit_insns()) { bf28607fbe529e David Daney 2011-07-05 2144 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID), cc33ae43797541 David Daney 2010-12-20 2145 label_tlbl_goaround1); cc33ae43797541 David Daney 2010-12-20 2146 } else { bf28607fbe529e David Daney 2011-07-05 2147 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID); bf28607fbe529e David Daney 2011-07-05 2148 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround1); cc33ae43797541 David Daney 2010-12-20 2149 } 6dd9344cfc41bc David Daney 2010-02-10 2150 uasm_i_nop(&p); 6dd9344cfc41bc David Daney 2010-02-10 2151 f39878cc5b09c7 Paul Burton 2017-06-02 2152 /* f39878cc5b09c7 Paul Burton 2017-06-02 2153 * Warn if something may race with us & replace the TLB entry f39878cc5b09c7 Paul Burton 2017-06-02 2154 * before we read it here. Everything with such races should f39878cc5b09c7 Paul Burton 2017-06-02 2155 * also have dedicated RiXi exception handlers, so this f39878cc5b09c7 Paul Burton 2017-06-02 2156 * shouldn't be hit. f39878cc5b09c7 Paul Burton 2017-06-02 2157 */ f39878cc5b09c7 Paul Burton 2017-06-02 2158 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path"); f39878cc5b09c7 Paul Burton 2017-06-02 2159 6dd9344cfc41bc David Daney 2010-02-10 2160 uasm_i_tlbr(&p); 73acc7df534ff4 Ralf Baechle 2013-06-20 2161 73acc7df534ff4 Ralf Baechle 2013-06-20 2162 switch (current_cpu_type()) { 73acc7df534ff4 Ralf Baechle 2013-06-20 2163 default: 77f3ee59ee7cfe Leonid Yegoshin 2014-11-24 2164 if (cpu_has_mips_r2_exec_hazard) { 73acc7df534ff4 Ralf Baechle 2013-06-20 2165 uasm_i_ehb(&p); bc431d2153cc29 Gustavo A. R. Silva 2021-07-13 2166 fallthrough; 73acc7df534ff4 Ralf Baechle 2013-06-20 2167 73acc7df534ff4 Ralf Baechle 2013-06-20 2168 case CPU_CAVIUM_OCTEON: 73acc7df534ff4 Ralf Baechle 2013-06-20 2169 case CPU_CAVIUM_OCTEON_PLUS: 73acc7df534ff4 Ralf Baechle 2013-06-20 2170 case CPU_CAVIUM_OCTEON2: 73acc7df534ff4 Ralf Baechle 2013-06-20 2171 break; 73acc7df534ff4 Ralf Baechle 2013-06-20 2172 } 73acc7df534ff4 Ralf Baechle 2013-06-20 2173 } 73acc7df534ff4 Ralf Baechle 2013-06-20 2174 6dd9344cfc41bc David Daney 2010-02-10 2175 /* Examine entrylo 0 or 1 based on ptr. */ cc33ae43797541 David Daney 2010-12-20 2176 if (use_bbit_insns()) { bf28607fbe529e David Daney 2011-07-05 2177 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8); cc33ae43797541 David Daney 2010-12-20 2178 } else { bf28607fbe529e David Daney 2011-07-05 2179 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t)); bf28607fbe529e David Daney 2011-07-05 2180 uasm_i_beqz(&p, wr.r3, 8); cc33ae43797541 David Daney 2010-12-20 2181 } bf28607fbe529e David Daney 2011-07-05 2182 /* load it in the delay slot*/ bf28607fbe529e David Daney 2011-07-05 2183 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0); bf28607fbe529e David Daney 2011-07-05 2184 /* load it if ptr is odd */ bf28607fbe529e David Daney 2011-07-05 2185 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1); 6dd9344cfc41bc David Daney 2010-02-10 2186 /* bf28607fbe529e David Daney 2011-07-05 2187 * If the entryLo (now in wr.r3) is valid (bit 1), RI or 6dd9344cfc41bc David Daney 2010-02-10 2188 * XI must have triggered it. 6dd9344cfc41bc David Daney 2010-02-10 2189 */ cc33ae43797541 David Daney 2010-12-20 2190 if (use_bbit_insns()) { bf28607fbe529e David Daney 2011-07-05 2191 uasm_il_bbit1(&p, &r, wr.r3, 1, label_nopage_tlbl); bf28607fbe529e David Daney 2011-07-05 2192 uasm_i_nop(&p); cc33ae43797541 David Daney 2010-12-20 2193 uasm_l_tlbl_goaround1(&l, p); cc33ae43797541 David Daney 2010-12-20 2194 } else { bf28607fbe529e David Daney 2011-07-05 2195 uasm_i_andi(&p, wr.r3, wr.r3, 2); bf28607fbe529e David Daney 2011-07-05 2196 uasm_il_bnez(&p, &r, wr.r3, label_nopage_tlbl); bf28607fbe529e David Daney 2011-07-05 2197 uasm_i_nop(&p); 6dd9344cfc41bc David Daney 2010-02-10 2198 } bf28607fbe529e David Daney 2011-07-05 2199 uasm_l_tlbl_goaround1(&l, p); cc33ae43797541 David Daney 2010-12-20 2200 } bbeeffec6f14a0 Paul Burton 2016-04-19 2201 build_make_valid(&p, &r, wr.r1, wr.r2, wr.r3); bf28607fbe529e David Daney 2011-07-05 2202 build_r4000_tlbchange_handler_tail(&p, &l, &r, wr.r1, wr.r2); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2203 aa1762f49c81a1 David Daney 2012-10-17 2204 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT fd062c847a8cea David Daney 2009-05-27 2205 /* fd062c847a8cea David Daney 2009-05-27 2206 * This is the entry point when build_r4000_tlbchange_handler_head fd062c847a8cea David Daney 2009-05-27 2207 * spots a huge page. fd062c847a8cea David Daney 2009-05-27 2208 */ fd062c847a8cea David Daney 2009-05-27 2209 uasm_l_tlb_huge_update(&l, p); bf28607fbe529e David Daney 2011-07-05 2210 iPTE_LW(&p, wr.r1, wr.r2); bf28607fbe529e David Daney 2011-07-05 2211 build_pte_present(&p, &r, wr.r1, wr.r2, wr.r3, label_nopage_tlbl); fd062c847a8cea David Daney 2009-05-27 2212 build_tlb_probe_entry(&p); 6dd9344cfc41bc David Daney 2010-02-10 2213 5890f70f15c52d Leonid Yegoshin 2014-07-15 2214 if (cpu_has_rixi && !cpu_has_rixiex) { 6dd9344cfc41bc David Daney 2010-02-10 2215 /* 6dd9344cfc41bc David Daney 2010-02-10 2216 * If the page is not _PAGE_VALID, RI or XI could not 6dd9344cfc41bc David Daney 2010-02-10 2217 * have triggered it. Skip the expensive test.. 6dd9344cfc41bc David Daney 2010-02-10 2218 */ cc33ae43797541 David Daney 2010-12-20 2219 if (use_bbit_insns()) { bf28607fbe529e David Daney 2011-07-05 2220 uasm_il_bbit0(&p, &r, wr.r1, ilog2(_PAGE_VALID), cc33ae43797541 David Daney 2010-12-20 2221 label_tlbl_goaround2); cc33ae43797541 David Daney 2010-12-20 2222 } else { bf28607fbe529e David Daney 2011-07-05 2223 uasm_i_andi(&p, wr.r3, wr.r1, _PAGE_VALID); bf28607fbe529e David Daney 2011-07-05 2224 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2); cc33ae43797541 David Daney 2010-12-20 2225 } 6dd9344cfc41bc David Daney 2010-02-10 2226 uasm_i_nop(&p); 6dd9344cfc41bc David Daney 2010-02-10 2227 f39878cc5b09c7 Paul Burton 2017-06-02 2228 /* f39878cc5b09c7 Paul Burton 2017-06-02 2229 * Warn if something may race with us & replace the TLB entry f39878cc5b09c7 Paul Burton 2017-06-02 2230 * before we read it here. Everything with such races should f39878cc5b09c7 Paul Burton 2017-06-02 2231 * also have dedicated RiXi exception handlers, so this f39878cc5b09c7 Paul Burton 2017-06-02 2232 * shouldn't be hit. f39878cc5b09c7 Paul Burton 2017-06-02 2233 */ f39878cc5b09c7 Paul Burton 2017-06-02 2234 WARN(cpu_has_tlbex_tlbp_race(), "Unhandled race in RiXi path"); f39878cc5b09c7 Paul Burton 2017-06-02 2235 6dd9344cfc41bc David Daney 2010-02-10 2236 uasm_i_tlbr(&p); 73acc7df534ff4 Ralf Baechle 2013-06-20 2237 73acc7df534ff4 Ralf Baechle 2013-06-20 2238 switch (current_cpu_type()) { 73acc7df534ff4 Ralf Baechle 2013-06-20 2239 default: 77f3ee59ee7cfe Leonid Yegoshin 2014-11-24 2240 if (cpu_has_mips_r2_exec_hazard) { 73acc7df534ff4 Ralf Baechle 2013-06-20 2241 uasm_i_ehb(&p); 73acc7df534ff4 Ralf Baechle 2013-06-20 2242 73acc7df534ff4 Ralf Baechle 2013-06-20 @2243 case CPU_CAVIUM_OCTEON: 73acc7df534ff4 Ralf Baechle 2013-06-20 2244 case CPU_CAVIUM_OCTEON_PLUS: 73acc7df534ff4 Ralf Baechle 2013-06-20 2245 case CPU_CAVIUM_OCTEON2: 73acc7df534ff4 Ralf Baechle 2013-06-20 2246 break; 73acc7df534ff4 Ralf Baechle 2013-06-20 2247 } 73acc7df534ff4 Ralf Baechle 2013-06-20 2248 } 73acc7df534ff4 Ralf Baechle 2013-06-20 2249 6dd9344cfc41bc David Daney 2010-02-10 2250 /* Examine entrylo 0 or 1 based on ptr. */ cc33ae43797541 David Daney 2010-12-20 2251 if (use_bbit_insns()) { bf28607fbe529e David Daney 2011-07-05 2252 uasm_i_bbit0(&p, wr.r2, ilog2(sizeof(pte_t)), 8); cc33ae43797541 David Daney 2010-12-20 2253 } else { bf28607fbe529e David Daney 2011-07-05 2254 uasm_i_andi(&p, wr.r3, wr.r2, sizeof(pte_t)); bf28607fbe529e David Daney 2011-07-05 2255 uasm_i_beqz(&p, wr.r3, 8); cc33ae43797541 David Daney 2010-12-20 2256 } bf28607fbe529e David Daney 2011-07-05 2257 /* load it in the delay slot*/ bf28607fbe529e David Daney 2011-07-05 2258 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO0); bf28607fbe529e David Daney 2011-07-05 2259 /* load it if ptr is odd */ bf28607fbe529e David Daney 2011-07-05 2260 UASM_i_MFC0(&p, wr.r3, C0_ENTRYLO1); 6dd9344cfc41bc David Daney 2010-02-10 2261 /* bf28607fbe529e David Daney 2011-07-05 2262 * If the entryLo (now in wr.r3) is valid (bit 1), RI or 6dd9344cfc41bc David Daney 2010-02-10 2263 * XI must have triggered it. 6dd9344cfc41bc David Daney 2010-02-10 2264 */ cc33ae43797541 David Daney 2010-12-20 2265 if (use_bbit_insns()) { bf28607fbe529e David Daney 2011-07-05 2266 uasm_il_bbit0(&p, &r, wr.r3, 1, label_tlbl_goaround2); cc33ae43797541 David Daney 2010-12-20 2267 } else { bf28607fbe529e David Daney 2011-07-05 2268 uasm_i_andi(&p, wr.r3, wr.r3, 2); bf28607fbe529e David Daney 2011-07-05 2269 uasm_il_beqz(&p, &r, wr.r3, label_tlbl_goaround2); cc33ae43797541 David Daney 2010-12-20 2270 } 0f4ccbc835036c David Daney 2011-09-16 2271 if (PM_DEFAULT_MASK == 0) 0f4ccbc835036c David Daney 2011-09-16 2272 uasm_i_nop(&p); 6dd9344cfc41bc David Daney 2010-02-10 2273 /* 6dd9344cfc41bc David Daney 2010-02-10 2274 * We clobbered C0_PAGEMASK, restore it. On the other branch 6dd9344cfc41bc David Daney 2010-02-10 2275 * it is restored in build_huge_tlb_write_entry. 6dd9344cfc41bc David Daney 2010-02-10 2276 */ bf28607fbe529e David Daney 2011-07-05 2277 build_restore_pagemask(&p, &r, wr.r3, label_nopage_tlbl, 0); 6dd9344cfc41bc David Daney 2010-02-10 2278 6dd9344cfc41bc David Daney 2010-02-10 2279 uasm_l_tlbl_goaround2(&l, p); 6dd9344cfc41bc David Daney 2010-02-10 2280 } bf28607fbe529e David Daney 2011-07-05 2281 uasm_i_ori(&p, wr.r1, wr.r1, (_PAGE_ACCESSED | _PAGE_VALID)); 0115f6cbf26663 Huacai Chen 2017-03-16 2282 build_huge_handler_tail(&p, &r, &l, wr.r1, wr.r2, 1); fd062c847a8cea David Daney 2009-05-27 2283 #endif fd062c847a8cea David Daney 2009-05-27 2284 e30ec4525d4731 Thiemo Seufer 2008-01-28 2285 uasm_l_nopage_tlbl(&l, p); e02e07e3127d8a Huacai Chen 2019-01-15 2286 if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) e02e07e3127d8a Huacai Chen 2019-01-15 2287 uasm_i_sync(&p, 0); bf28607fbe529e David Daney 2011-07-05 2288 build_restore_work_registers(&p); 2a0b24f56c2492 Steven J. Hill 2013-03-25 2289 #ifdef CONFIG_CPU_MICROMIPS 2a0b24f56c2492 Steven J. Hill 2013-03-25 2290 if ((unsigned long)tlb_do_page_fault_0 & 1) { 2a0b24f56c2492 Steven J. Hill 2013-03-25 2291 uasm_i_lui(&p, K0, uasm_rel_hi((long)tlb_do_page_fault_0)); 2a0b24f56c2492 Steven J. Hill 2013-03-25 2292 uasm_i_addiu(&p, K0, K0, uasm_rel_lo((long)tlb_do_page_fault_0)); 2a0b24f56c2492 Steven J. Hill 2013-03-25 2293 uasm_i_jr(&p, K0); 2a0b24f56c2492 Steven J. Hill 2013-03-25 2294 } else 2a0b24f56c2492 Steven J. Hill 2013-03-25 2295 #endif e30ec4525d4731 Thiemo Seufer 2008-01-28 2296 uasm_i_j(&p, (unsigned long)tlb_do_page_fault_0 & 0x0fffffff); e30ec4525d4731 Thiemo Seufer 2008-01-28 2297 uasm_i_nop(&p); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2298 4bcb4ad6634ea1 Paul Burton 2018-08-10 2299 if (p >= (u32 *)handle_tlbl_end) ^1da177e4c3f41 Linus Torvalds 2005-04-16 2300 panic("TLB load handler fastpath space exceeded"); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2301 e30ec4525d4731 Thiemo Seufer 2008-01-28 2302 uasm_resolve_relocs(relocs, labels); e30ec4525d4731 Thiemo Seufer 2008-01-28 2303 pr_debug("Wrote TLB load handler fastpath (%u instructions).\n", 4bcb4ad6634ea1 Paul Burton 2018-08-10 2304 (unsigned int)(p - (u32 *)handle_tlbl)); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2305 4bcb4ad6634ea1 Paul Burton 2018-08-10 2306 dump_handler("r4000_tlb_load", handle_tlbl, handle_tlbl_end); ^1da177e4c3f41 Linus Torvalds 2005-04-16 2307 } ^1da177e4c3f41 Linus Torvalds 2005-04-16 2308 :::::: The code at line 2243 was first introduced by commit :::::: 73acc7df534ff458a81435178dab3ea037ed6d78 MIPS: Fix TLBR-use hazards for R2 cores in the TLB reload handlers :::::: TO: Ralf Baechle <ralf(a)linux-mips.org&gt; :::::: CC: Ralf Baechle <ralf(a)linux-mips.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org