1 /* 2 * Copyright (C) 2001 Ben. Herrenschmidt (benh@kernel.crashing.org) 3 * 4 * Modifications for ppc64: 5 * Copyright (C) 2003 Dave Engebretsen <engebret@us.ibm.com> 6 * 7 * Copyright 2008 Michael Ellerman, IBM Corporation. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 */ 14 15 #include <linux/types.h> 16 #include <linux/jump_label.h> 17 #include <linux/kernel.h> 18 #include <linux/string.h> 19 #include <linux/init.h> 20 #include <linux/sched/mm.h> 21 #include <asm/cputable.h> 22 #include <asm/code-patching.h> 23 #include <asm/page.h> 24 #include <asm/sections.h> 25 #include <asm/setup.h> 26 #include <asm/firmware.h> 27 28 struct fixup_entry { 29 unsigned long mask; 30 unsigned long value; 31 long start_off; 32 long end_off; 33 long alt_start_off; 34 long alt_end_off; 35 }; 36 37 static unsigned int *calc_addr(struct fixup_entry *fcur, long offset) 38 { 39 /* 40 * We store the offset to the code as a negative offset from 41 * the start of the alt_entry, to support the VDSO. This 42 * routine converts that back into an actual address. 43 */ 44 return (unsigned int *)((unsigned long)fcur + offset); 45 } 46 47 static int patch_alt_instruction(unsigned int *src, unsigned int *dest, 48 unsigned int *alt_start, unsigned int *alt_end) 49 { 50 unsigned int instr; 51 52 instr = *src; 53 54 if (instr_is_relative_branch(*src)) { 55 unsigned int *target = (unsigned int *)branch_target(src); 56 57 /* Branch within the section doesn't need translating */ 58 if (target < alt_start || target >= alt_end) { 59 instr = translate_branch(dest, src); 60 if (!instr) 61 return 1; 62 } 63 } 64 65 raw_patch_instruction(dest, instr); 66 67 return 0; 68 } 69 70 static int patch_feature_section(unsigned long value, struct fixup_entry *fcur) 71 { 72 unsigned int *start, *end, *alt_start, *alt_end, *src, *dest; 73 74 start = calc_addr(fcur, fcur->start_off); 75 end = calc_addr(fcur, fcur->end_off); 76 alt_start = calc_addr(fcur, fcur->alt_start_off); 77 alt_end = calc_addr(fcur, fcur->alt_end_off); 78 79 if ((alt_end - alt_start) > (end - start)) 80 return 1; 81 82 if ((value & fcur->mask) == fcur->value) 83 return 0; 84 85 src = alt_start; 86 dest = start; 87 88 for (; src < alt_end; src++, dest++) { 89 if (patch_alt_instruction(src, dest, alt_start, alt_end)) 90 return 1; 91 } 92 93 for (; dest < end; dest++) 94 raw_patch_instruction(dest, PPC_INST_NOP); 95 96 return 0; 97 } 98 99 void do_feature_fixups(unsigned long value, void *fixup_start, void *fixup_end) 100 { 101 struct fixup_entry *fcur, *fend; 102 103 fcur = fixup_start; 104 fend = fixup_end; 105 106 for (; fcur < fend; fcur++) { 107 if (patch_feature_section(value, fcur)) { 108 WARN_ON(1); 109 printk("Unable to patch feature section at %p - %p" \ 110 " with %p - %p\n", 111 calc_addr(fcur, fcur->start_off), 112 calc_addr(fcur, fcur->end_off), 113 calc_addr(fcur, fcur->alt_start_off), 114 calc_addr(fcur, fcur->alt_end_off)); 115 } 116 } 117 } 118 119 #ifdef CONFIG_PPC_BOOK3S_64 120 void do_rfi_flush_fixups(enum l1d_flush_type types) 121 { 122 unsigned int instrs[3], *dest; 123 long *start, *end; 124 int i; 125 126 start = PTRRELOC(&__start___rfi_flush_fixup), 127 end = PTRRELOC(&__stop___rfi_flush_fixup); 128 129 instrs[0] = 0x60000000; /* nop */ 130 instrs[1] = 0x60000000; /* nop */ 131 instrs[2] = 0x60000000; /* nop */ 132 133 if (types & L1D_FLUSH_FALLBACK) 134 /* b .+16 to fallback flush */ 135 instrs[0] = 0x48000010; 136 137 i = 0; 138 if (types & L1D_FLUSH_ORI) { 139 instrs[i++] = 0x63ff0000; /* ori 31,31,0 speculation barrier */ 140 instrs[i++] = 0x63de0000; /* ori 30,30,0 L1d flush*/ 141 } 142 143 if (types & L1D_FLUSH_MTTRIG) 144 instrs[i++] = 0x7c12dba6; /* mtspr TRIG2,r0 (SPR #882) */ 145 146 for (i = 0; start < end; start++, i++) { 147 dest = (void *)start + *start; 148 149 pr_devel("patching dest %lx\n", (unsigned long)dest); 150 151 patch_instruction(dest, instrs[0]); 152 patch_instruction(dest + 1, instrs[1]); 153 patch_instruction(dest + 2, instrs[2]); 154 } 155 156 printk(KERN_DEBUG "rfi-flush: patched %d locations\n", i); 157 } 158 #endif /* CONFIG_PPC_BOOK3S_64 */ 159 160 void do_lwsync_fixups(unsigned long value, void *fixup_start, void *fixup_end) 161 { 162 long *start, *end; 163 unsigned int *dest; 164 165 if (!(value & CPU_FTR_LWSYNC)) 166 return ; 167 168 start = fixup_start; 169 end = fixup_end; 170 171 for (; start < end; start++) { 172 dest = (void *)start + *start; 173 raw_patch_instruction(dest, PPC_INST_LWSYNC); 174 } 175 } 176 177 static void do_final_fixups(void) 178 { 179 #if defined(CONFIG_PPC64) && defined(CONFIG_RELOCATABLE) 180 int *src, *dest; 181 unsigned long length; 182 183 if (PHYSICAL_START == 0) 184 return; 185 186 src = (int *)(KERNELBASE + PHYSICAL_START); 187 dest = (int *)KERNELBASE; 188 length = (__end_interrupts - _stext) / sizeof(int); 189 190 while (length--) { 191 raw_patch_instruction(dest, *src); 192 src++; 193 dest++; 194 } 195 #endif 196 } 197 198 static unsigned long __initdata saved_cpu_features; 199 static unsigned int __initdata saved_mmu_features; 200 #ifdef CONFIG_PPC64 201 static unsigned long __initdata saved_firmware_features; 202 #endif 203 204 void __init apply_feature_fixups(void) 205 { 206 struct cpu_spec *spec = PTRRELOC(*PTRRELOC(&cur_cpu_spec)); 207 208 *PTRRELOC(&saved_cpu_features) = spec->cpu_features; 209 *PTRRELOC(&saved_mmu_features) = spec->mmu_features; 210 211 /* 212 * Apply the CPU-specific and firmware specific fixups to kernel text 213 * (nop out sections not relevant to this CPU or this firmware). 214 */ 215 do_feature_fixups(spec->cpu_features, 216 PTRRELOC(&__start___ftr_fixup), 217 PTRRELOC(&__stop___ftr_fixup)); 218 219 do_feature_fixups(spec->mmu_features, 220 PTRRELOC(&__start___mmu_ftr_fixup), 221 PTRRELOC(&__stop___mmu_ftr_fixup)); 222 223 do_lwsync_fixups(spec->cpu_features, 224 PTRRELOC(&__start___lwsync_fixup), 225 PTRRELOC(&__stop___lwsync_fixup)); 226 227 #ifdef CONFIG_PPC64 228 saved_firmware_features = powerpc_firmware_features; 229 do_feature_fixups(powerpc_firmware_features, 230 &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup); 231 #endif 232 do_final_fixups(); 233 } 234 235 void __init setup_feature_keys(void) 236 { 237 /* 238 * Initialise jump label. This causes all the cpu/mmu_has_feature() 239 * checks to take on their correct polarity based on the current set of 240 * CPU/MMU features. 241 */ 242 jump_label_init(); 243 cpu_feature_keys_init(); 244 mmu_feature_keys_init(); 245 } 246 247 static int __init check_features(void) 248 { 249 WARN(saved_cpu_features != cur_cpu_spec->cpu_features, 250 "CPU features changed after feature patching!\n"); 251 WARN(saved_mmu_features != cur_cpu_spec->mmu_features, 252 "MMU features changed after feature patching!\n"); 253 #ifdef CONFIG_PPC64 254 WARN(saved_firmware_features != powerpc_firmware_features, 255 "Firmware features changed after feature patching!\n"); 256 #endif 257 258 return 0; 259 } 260 late_initcall(check_features); 261 262 #ifdef CONFIG_FTR_FIXUP_SELFTEST 263 264 #define check(x) \ 265 if (!(x)) printk("feature-fixups: test failed at line %d\n", __LINE__); 266 267 /* This must be after the text it fixes up, vmlinux.lds.S enforces that atm */ 268 static struct fixup_entry fixup; 269 270 static long calc_offset(struct fixup_entry *entry, unsigned int *p) 271 { 272 return (unsigned long)p - (unsigned long)entry; 273 } 274 275 static void test_basic_patching(void) 276 { 277 extern unsigned int ftr_fixup_test1[]; 278 extern unsigned int end_ftr_fixup_test1[]; 279 extern unsigned int ftr_fixup_test1_orig[]; 280 extern unsigned int ftr_fixup_test1_expected[]; 281 int size = end_ftr_fixup_test1 - ftr_fixup_test1; 282 283 fixup.value = fixup.mask = 8; 284 fixup.start_off = calc_offset(&fixup, ftr_fixup_test1 + 1); 285 fixup.end_off = calc_offset(&fixup, ftr_fixup_test1 + 2); 286 fixup.alt_start_off = fixup.alt_end_off = 0; 287 288 /* Sanity check */ 289 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0); 290 291 /* Check we don't patch if the value matches */ 292 patch_feature_section(8, &fixup); 293 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0); 294 295 /* Check we do patch if the value doesn't match */ 296 patch_feature_section(0, &fixup); 297 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0); 298 299 /* Check we do patch if the mask doesn't match */ 300 memcpy(ftr_fixup_test1, ftr_fixup_test1_orig, size); 301 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_orig, size) == 0); 302 patch_feature_section(~8, &fixup); 303 check(memcmp(ftr_fixup_test1, ftr_fixup_test1_expected, size) == 0); 304 } 305 306 static void test_alternative_patching(void) 307 { 308 extern unsigned int ftr_fixup_test2[]; 309 extern unsigned int end_ftr_fixup_test2[]; 310 extern unsigned int ftr_fixup_test2_orig[]; 311 extern unsigned int ftr_fixup_test2_alt[]; 312 extern unsigned int ftr_fixup_test2_expected[]; 313 int size = end_ftr_fixup_test2 - ftr_fixup_test2; 314 315 fixup.value = fixup.mask = 0xF; 316 fixup.start_off = calc_offset(&fixup, ftr_fixup_test2 + 1); 317 fixup.end_off = calc_offset(&fixup, ftr_fixup_test2 + 2); 318 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test2_alt); 319 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test2_alt + 1); 320 321 /* Sanity check */ 322 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0); 323 324 /* Check we don't patch if the value matches */ 325 patch_feature_section(0xF, &fixup); 326 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0); 327 328 /* Check we do patch if the value doesn't match */ 329 patch_feature_section(0, &fixup); 330 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0); 331 332 /* Check we do patch if the mask doesn't match */ 333 memcpy(ftr_fixup_test2, ftr_fixup_test2_orig, size); 334 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_orig, size) == 0); 335 patch_feature_section(~0xF, &fixup); 336 check(memcmp(ftr_fixup_test2, ftr_fixup_test2_expected, size) == 0); 337 } 338 339 static void test_alternative_case_too_big(void) 340 { 341 extern unsigned int ftr_fixup_test3[]; 342 extern unsigned int end_ftr_fixup_test3[]; 343 extern unsigned int ftr_fixup_test3_orig[]; 344 extern unsigned int ftr_fixup_test3_alt[]; 345 int size = end_ftr_fixup_test3 - ftr_fixup_test3; 346 347 fixup.value = fixup.mask = 0xC; 348 fixup.start_off = calc_offset(&fixup, ftr_fixup_test3 + 1); 349 fixup.end_off = calc_offset(&fixup, ftr_fixup_test3 + 2); 350 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test3_alt); 351 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test3_alt + 2); 352 353 /* Sanity check */ 354 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0); 355 356 /* Expect nothing to be patched, and the error returned to us */ 357 check(patch_feature_section(0xF, &fixup) == 1); 358 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0); 359 check(patch_feature_section(0, &fixup) == 1); 360 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0); 361 check(patch_feature_section(~0xF, &fixup) == 1); 362 check(memcmp(ftr_fixup_test3, ftr_fixup_test3_orig, size) == 0); 363 } 364 365 static void test_alternative_case_too_small(void) 366 { 367 extern unsigned int ftr_fixup_test4[]; 368 extern unsigned int end_ftr_fixup_test4[]; 369 extern unsigned int ftr_fixup_test4_orig[]; 370 extern unsigned int ftr_fixup_test4_alt[]; 371 extern unsigned int ftr_fixup_test4_expected[]; 372 int size = end_ftr_fixup_test4 - ftr_fixup_test4; 373 unsigned long flag; 374 375 /* Check a high-bit flag */ 376 flag = 1UL << ((sizeof(unsigned long) - 1) * 8); 377 fixup.value = fixup.mask = flag; 378 fixup.start_off = calc_offset(&fixup, ftr_fixup_test4 + 1); 379 fixup.end_off = calc_offset(&fixup, ftr_fixup_test4 + 5); 380 fixup.alt_start_off = calc_offset(&fixup, ftr_fixup_test4_alt); 381 fixup.alt_end_off = calc_offset(&fixup, ftr_fixup_test4_alt + 2); 382 383 /* Sanity check */ 384 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0); 385 386 /* Check we don't patch if the value matches */ 387 patch_feature_section(flag, &fixup); 388 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0); 389 390 /* Check we do patch if the value doesn't match */ 391 patch_feature_section(0, &fixup); 392 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0); 393 394 /* Check we do patch if the mask doesn't match */ 395 memcpy(ftr_fixup_test4, ftr_fixup_test4_orig, size); 396 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_orig, size) == 0); 397 patch_feature_section(~flag, &fixup); 398 check(memcmp(ftr_fixup_test4, ftr_fixup_test4_expected, size) == 0); 399 } 400 401 static void test_alternative_case_with_branch(void) 402 { 403 extern unsigned int ftr_fixup_test5[]; 404 extern unsigned int end_ftr_fixup_test5[]; 405 extern unsigned int ftr_fixup_test5_expected[]; 406 int size = end_ftr_fixup_test5 - ftr_fixup_test5; 407 408 check(memcmp(ftr_fixup_test5, ftr_fixup_test5_expected, size) == 0); 409 } 410 411 static void test_alternative_case_with_external_branch(void) 412 { 413 extern unsigned int ftr_fixup_test6[]; 414 extern unsigned int end_ftr_fixup_test6[]; 415 extern unsigned int ftr_fixup_test6_expected[]; 416 int size = end_ftr_fixup_test6 - ftr_fixup_test6; 417 418 check(memcmp(ftr_fixup_test6, ftr_fixup_test6_expected, size) == 0); 419 } 420 421 static void test_cpu_macros(void) 422 { 423 extern u8 ftr_fixup_test_FTR_macros[]; 424 extern u8 ftr_fixup_test_FTR_macros_expected[]; 425 unsigned long size = ftr_fixup_test_FTR_macros_expected - 426 ftr_fixup_test_FTR_macros; 427 428 /* The fixups have already been done for us during boot */ 429 check(memcmp(ftr_fixup_test_FTR_macros, 430 ftr_fixup_test_FTR_macros_expected, size) == 0); 431 } 432 433 static void test_fw_macros(void) 434 { 435 #ifdef CONFIG_PPC64 436 extern u8 ftr_fixup_test_FW_FTR_macros[]; 437 extern u8 ftr_fixup_test_FW_FTR_macros_expected[]; 438 unsigned long size = ftr_fixup_test_FW_FTR_macros_expected - 439 ftr_fixup_test_FW_FTR_macros; 440 441 /* The fixups have already been done for us during boot */ 442 check(memcmp(ftr_fixup_test_FW_FTR_macros, 443 ftr_fixup_test_FW_FTR_macros_expected, size) == 0); 444 #endif 445 } 446 447 static void test_lwsync_macros(void) 448 { 449 extern u8 lwsync_fixup_test[]; 450 extern u8 end_lwsync_fixup_test[]; 451 extern u8 lwsync_fixup_test_expected_LWSYNC[]; 452 extern u8 lwsync_fixup_test_expected_SYNC[]; 453 unsigned long size = end_lwsync_fixup_test - 454 lwsync_fixup_test; 455 456 /* The fixups have already been done for us during boot */ 457 if (cur_cpu_spec->cpu_features & CPU_FTR_LWSYNC) { 458 check(memcmp(lwsync_fixup_test, 459 lwsync_fixup_test_expected_LWSYNC, size) == 0); 460 } else { 461 check(memcmp(lwsync_fixup_test, 462 lwsync_fixup_test_expected_SYNC, size) == 0); 463 } 464 } 465 466 static int __init test_feature_fixups(void) 467 { 468 printk(KERN_DEBUG "Running feature fixup self-tests ...\n"); 469 470 test_basic_patching(); 471 test_alternative_patching(); 472 test_alternative_case_too_big(); 473 test_alternative_case_too_small(); 474 test_alternative_case_with_branch(); 475 test_alternative_case_with_external_branch(); 476 test_cpu_macros(); 477 test_fw_macros(); 478 test_lwsync_macros(); 479 480 return 0; 481 } 482 late_initcall(test_feature_fixups); 483 484 #endif /* CONFIG_FTR_FIXUP_SELFTEST */ 485