1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright IBM Corp. 2006 4 */ 5 6 #include <linux/memory_hotplug.h> 7 #include <linux/memblock.h> 8 #include <linux/pfn.h> 9 #include <linux/mm.h> 10 #include <linux/init.h> 11 #include <linux/list.h> 12 #include <linux/hugetlb.h> 13 #include <linux/slab.h> 14 #include <linux/sort.h> 15 #include <asm/cacheflush.h> 16 #include <asm/nospec-branch.h> 17 #include <asm/pgalloc.h> 18 #include <asm/setup.h> 19 #include <asm/tlbflush.h> 20 #include <asm/sections.h> 21 #include <asm/set_memory.h> 22 23 static DEFINE_MUTEX(vmem_mutex); 24 25 static void __ref *vmem_alloc_pages(unsigned int order) 26 { 27 unsigned long size = PAGE_SIZE << order; 28 29 if (slab_is_available()) 30 return (void *)__get_free_pages(GFP_KERNEL, order); 31 return memblock_alloc(size, size); 32 } 33 34 static void vmem_free_pages(unsigned long addr, int order) 35 { 36 /* We don't expect boot memory to be removed ever. */ 37 if (!slab_is_available() || 38 WARN_ON_ONCE(PageReserved(virt_to_page(addr)))) 39 return; 40 free_pages(addr, order); 41 } 42 43 void *vmem_crst_alloc(unsigned long val) 44 { 45 unsigned long *table; 46 47 table = vmem_alloc_pages(CRST_ALLOC_ORDER); 48 if (table) 49 crst_table_init(table, val); 50 return table; 51 } 52 53 pte_t __ref *vmem_pte_alloc(void) 54 { 55 unsigned long size = PTRS_PER_PTE * sizeof(pte_t); 56 pte_t *pte; 57 58 if (slab_is_available()) 59 pte = (pte_t *) page_table_alloc(&init_mm); 60 else 61 pte = (pte_t *) memblock_alloc(size, size); 62 if (!pte) 63 return NULL; 64 memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE); 65 return pte; 66 } 67 68 static void vmem_pte_free(unsigned long *table) 69 { 70 /* We don't expect boot memory to be removed ever. */ 71 if (!slab_is_available() || 72 WARN_ON_ONCE(PageReserved(virt_to_page(table)))) 73 return; 74 page_table_free(&init_mm, table); 75 } 76 77 #define PAGE_UNUSED 0xFD 78 79 /* 80 * The unused vmemmap range, which was not yet memset(PAGE_UNUSED) ranges 81 * from unused_sub_pmd_start to next PMD_SIZE boundary. 82 */ 83 static unsigned long unused_sub_pmd_start; 84 85 static void vmemmap_flush_unused_sub_pmd(void) 86 { 87 if (!unused_sub_pmd_start) 88 return; 89 memset((void *)unused_sub_pmd_start, PAGE_UNUSED, 90 ALIGN(unused_sub_pmd_start, PMD_SIZE) - unused_sub_pmd_start); 91 unused_sub_pmd_start = 0; 92 } 93 94 static void vmemmap_mark_sub_pmd_used(unsigned long start, unsigned long end) 95 { 96 /* 97 * As we expect to add in the same granularity as we remove, it's 98 * sufficient to mark only some piece used to block the memmap page from 99 * getting removed (just in case the memmap never gets initialized, 100 * e.g., because the memory block never gets onlined). 101 */ 102 memset((void *)start, 0, sizeof(struct page)); 103 } 104 105 static void vmemmap_use_sub_pmd(unsigned long start, unsigned long end) 106 { 107 /* 108 * We only optimize if the new used range directly follows the 109 * previously unused range (esp., when populating consecutive sections). 110 */ 111 if (unused_sub_pmd_start == start) { 112 unused_sub_pmd_start = end; 113 if (likely(IS_ALIGNED(unused_sub_pmd_start, PMD_SIZE))) 114 unused_sub_pmd_start = 0; 115 return; 116 } 117 vmemmap_flush_unused_sub_pmd(); 118 vmemmap_mark_sub_pmd_used(start, end); 119 } 120 121 static void vmemmap_use_new_sub_pmd(unsigned long start, unsigned long end) 122 { 123 unsigned long page = ALIGN_DOWN(start, PMD_SIZE); 124 125 vmemmap_flush_unused_sub_pmd(); 126 127 /* Could be our memmap page is filled with PAGE_UNUSED already ... */ 128 vmemmap_mark_sub_pmd_used(start, end); 129 130 /* Mark the unused parts of the new memmap page PAGE_UNUSED. */ 131 if (!IS_ALIGNED(start, PMD_SIZE)) 132 memset((void *)page, PAGE_UNUSED, start - page); 133 /* 134 * We want to avoid memset(PAGE_UNUSED) when populating the vmemmap of 135 * consecutive sections. Remember for the last added PMD the last 136 * unused range in the populated PMD. 137 */ 138 if (!IS_ALIGNED(end, PMD_SIZE)) 139 unused_sub_pmd_start = end; 140 } 141 142 /* Returns true if the PMD is completely unused and can be freed. */ 143 static bool vmemmap_unuse_sub_pmd(unsigned long start, unsigned long end) 144 { 145 unsigned long page = ALIGN_DOWN(start, PMD_SIZE); 146 147 vmemmap_flush_unused_sub_pmd(); 148 memset((void *)start, PAGE_UNUSED, end - start); 149 return !memchr_inv((void *)page, PAGE_UNUSED, PMD_SIZE); 150 } 151 152 /* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */ 153 static int __ref modify_pte_table(pmd_t *pmd, unsigned long addr, 154 unsigned long end, bool add, bool direct) 155 { 156 unsigned long prot, pages = 0; 157 int ret = -ENOMEM; 158 pte_t *pte; 159 160 prot = pgprot_val(PAGE_KERNEL); 161 if (!MACHINE_HAS_NX) 162 prot &= ~_PAGE_NOEXEC; 163 164 pte = pte_offset_kernel(pmd, addr); 165 for (; addr < end; addr += PAGE_SIZE, pte++) { 166 if (!add) { 167 if (pte_none(*pte)) 168 continue; 169 if (!direct) 170 vmem_free_pages((unsigned long) pfn_to_virt(pte_pfn(*pte)), 0); 171 pte_clear(&init_mm, addr, pte); 172 } else if (pte_none(*pte)) { 173 if (!direct) { 174 void *new_page = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE); 175 176 if (!new_page) 177 goto out; 178 set_pte(pte, __pte(__pa(new_page) | prot)); 179 } else { 180 set_pte(pte, __pte(__pa(addr) | prot)); 181 } 182 } else { 183 continue; 184 } 185 pages++; 186 } 187 ret = 0; 188 out: 189 if (direct) 190 update_page_count(PG_DIRECT_MAP_4K, add ? pages : -pages); 191 return ret; 192 } 193 194 static void try_free_pte_table(pmd_t *pmd, unsigned long start) 195 { 196 pte_t *pte; 197 int i; 198 199 /* We can safely assume this is fully in 1:1 mapping & vmemmap area */ 200 pte = pte_offset_kernel(pmd, start); 201 for (i = 0; i < PTRS_PER_PTE; i++, pte++) { 202 if (!pte_none(*pte)) 203 return; 204 } 205 vmem_pte_free((unsigned long *) pmd_deref(*pmd)); 206 pmd_clear(pmd); 207 } 208 209 /* __ref: we'll only call vmemmap_alloc_block() via vmemmap_populate() */ 210 static int __ref modify_pmd_table(pud_t *pud, unsigned long addr, 211 unsigned long end, bool add, bool direct) 212 { 213 unsigned long next, prot, pages = 0; 214 int ret = -ENOMEM; 215 pmd_t *pmd; 216 pte_t *pte; 217 218 prot = pgprot_val(SEGMENT_KERNEL); 219 if (!MACHINE_HAS_NX) 220 prot &= ~_SEGMENT_ENTRY_NOEXEC; 221 222 pmd = pmd_offset(pud, addr); 223 for (; addr < end; addr = next, pmd++) { 224 next = pmd_addr_end(addr, end); 225 if (!add) { 226 if (pmd_none(*pmd)) 227 continue; 228 if (pmd_large(*pmd)) { 229 if (IS_ALIGNED(addr, PMD_SIZE) && 230 IS_ALIGNED(next, PMD_SIZE)) { 231 if (!direct) 232 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE)); 233 pmd_clear(pmd); 234 pages++; 235 } else if (!direct && vmemmap_unuse_sub_pmd(addr, next)) { 236 vmem_free_pages(pmd_deref(*pmd), get_order(PMD_SIZE)); 237 pmd_clear(pmd); 238 } 239 continue; 240 } 241 } else if (pmd_none(*pmd)) { 242 if (IS_ALIGNED(addr, PMD_SIZE) && 243 IS_ALIGNED(next, PMD_SIZE) && 244 MACHINE_HAS_EDAT1 && direct && 245 !debug_pagealloc_enabled()) { 246 set_pmd(pmd, __pmd(__pa(addr) | prot)); 247 pages++; 248 continue; 249 } else if (!direct && MACHINE_HAS_EDAT1) { 250 void *new_page; 251 252 /* 253 * Use 1MB frames for vmemmap if available. We 254 * always use large frames even if they are only 255 * partially used. Otherwise we would have also 256 * page tables since vmemmap_populate gets 257 * called for each section separately. 258 */ 259 new_page = vmemmap_alloc_block(PMD_SIZE, NUMA_NO_NODE); 260 if (new_page) { 261 set_pmd(pmd, __pmd(__pa(new_page) | prot)); 262 if (!IS_ALIGNED(addr, PMD_SIZE) || 263 !IS_ALIGNED(next, PMD_SIZE)) { 264 vmemmap_use_new_sub_pmd(addr, next); 265 } 266 continue; 267 } 268 } 269 pte = vmem_pte_alloc(); 270 if (!pte) 271 goto out; 272 pmd_populate(&init_mm, pmd, pte); 273 } else if (pmd_large(*pmd)) { 274 if (!direct) 275 vmemmap_use_sub_pmd(addr, next); 276 continue; 277 } 278 ret = modify_pte_table(pmd, addr, next, add, direct); 279 if (ret) 280 goto out; 281 if (!add) 282 try_free_pte_table(pmd, addr & PMD_MASK); 283 } 284 ret = 0; 285 out: 286 if (direct) 287 update_page_count(PG_DIRECT_MAP_1M, add ? pages : -pages); 288 return ret; 289 } 290 291 static void try_free_pmd_table(pud_t *pud, unsigned long start) 292 { 293 const unsigned long end = start + PUD_SIZE; 294 pmd_t *pmd; 295 int i; 296 297 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */ 298 if (end > VMALLOC_START) 299 return; 300 301 pmd = pmd_offset(pud, start); 302 for (i = 0; i < PTRS_PER_PMD; i++, pmd++) 303 if (!pmd_none(*pmd)) 304 return; 305 vmem_free_pages(pud_deref(*pud), CRST_ALLOC_ORDER); 306 pud_clear(pud); 307 } 308 309 static int modify_pud_table(p4d_t *p4d, unsigned long addr, unsigned long end, 310 bool add, bool direct) 311 { 312 unsigned long next, prot, pages = 0; 313 int ret = -ENOMEM; 314 pud_t *pud; 315 pmd_t *pmd; 316 317 prot = pgprot_val(REGION3_KERNEL); 318 if (!MACHINE_HAS_NX) 319 prot &= ~_REGION_ENTRY_NOEXEC; 320 pud = pud_offset(p4d, addr); 321 for (; addr < end; addr = next, pud++) { 322 next = pud_addr_end(addr, end); 323 if (!add) { 324 if (pud_none(*pud)) 325 continue; 326 if (pud_large(*pud)) { 327 if (IS_ALIGNED(addr, PUD_SIZE) && 328 IS_ALIGNED(next, PUD_SIZE)) { 329 pud_clear(pud); 330 pages++; 331 } 332 continue; 333 } 334 } else if (pud_none(*pud)) { 335 if (IS_ALIGNED(addr, PUD_SIZE) && 336 IS_ALIGNED(next, PUD_SIZE) && 337 MACHINE_HAS_EDAT2 && direct && 338 !debug_pagealloc_enabled()) { 339 set_pud(pud, __pud(__pa(addr) | prot)); 340 pages++; 341 continue; 342 } 343 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); 344 if (!pmd) 345 goto out; 346 pud_populate(&init_mm, pud, pmd); 347 } else if (pud_large(*pud)) { 348 continue; 349 } 350 ret = modify_pmd_table(pud, addr, next, add, direct); 351 if (ret) 352 goto out; 353 if (!add) 354 try_free_pmd_table(pud, addr & PUD_MASK); 355 } 356 ret = 0; 357 out: 358 if (direct) 359 update_page_count(PG_DIRECT_MAP_2G, add ? pages : -pages); 360 return ret; 361 } 362 363 static void try_free_pud_table(p4d_t *p4d, unsigned long start) 364 { 365 const unsigned long end = start + P4D_SIZE; 366 pud_t *pud; 367 int i; 368 369 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */ 370 if (end > VMALLOC_START) 371 return; 372 373 pud = pud_offset(p4d, start); 374 for (i = 0; i < PTRS_PER_PUD; i++, pud++) { 375 if (!pud_none(*pud)) 376 return; 377 } 378 vmem_free_pages(p4d_deref(*p4d), CRST_ALLOC_ORDER); 379 p4d_clear(p4d); 380 } 381 382 static int modify_p4d_table(pgd_t *pgd, unsigned long addr, unsigned long end, 383 bool add, bool direct) 384 { 385 unsigned long next; 386 int ret = -ENOMEM; 387 p4d_t *p4d; 388 pud_t *pud; 389 390 p4d = p4d_offset(pgd, addr); 391 for (; addr < end; addr = next, p4d++) { 392 next = p4d_addr_end(addr, end); 393 if (!add) { 394 if (p4d_none(*p4d)) 395 continue; 396 } else if (p4d_none(*p4d)) { 397 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY); 398 if (!pud) 399 goto out; 400 p4d_populate(&init_mm, p4d, pud); 401 } 402 ret = modify_pud_table(p4d, addr, next, add, direct); 403 if (ret) 404 goto out; 405 if (!add) 406 try_free_pud_table(p4d, addr & P4D_MASK); 407 } 408 ret = 0; 409 out: 410 return ret; 411 } 412 413 static void try_free_p4d_table(pgd_t *pgd, unsigned long start) 414 { 415 const unsigned long end = start + PGDIR_SIZE; 416 p4d_t *p4d; 417 int i; 418 419 /* Don't mess with any tables not fully in 1:1 mapping & vmemmap area */ 420 if (end > VMALLOC_START) 421 return; 422 423 p4d = p4d_offset(pgd, start); 424 for (i = 0; i < PTRS_PER_P4D; i++, p4d++) { 425 if (!p4d_none(*p4d)) 426 return; 427 } 428 vmem_free_pages(pgd_deref(*pgd), CRST_ALLOC_ORDER); 429 pgd_clear(pgd); 430 } 431 432 static int modify_pagetable(unsigned long start, unsigned long end, bool add, 433 bool direct) 434 { 435 unsigned long addr, next; 436 int ret = -ENOMEM; 437 pgd_t *pgd; 438 p4d_t *p4d; 439 440 if (WARN_ON_ONCE(!PAGE_ALIGNED(start | end))) 441 return -EINVAL; 442 for (addr = start; addr < end; addr = next) { 443 next = pgd_addr_end(addr, end); 444 pgd = pgd_offset_k(addr); 445 446 if (!add) { 447 if (pgd_none(*pgd)) 448 continue; 449 } else if (pgd_none(*pgd)) { 450 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY); 451 if (!p4d) 452 goto out; 453 pgd_populate(&init_mm, pgd, p4d); 454 } 455 ret = modify_p4d_table(pgd, addr, next, add, direct); 456 if (ret) 457 goto out; 458 if (!add) 459 try_free_p4d_table(pgd, addr & PGDIR_MASK); 460 } 461 ret = 0; 462 out: 463 if (!add) 464 flush_tlb_kernel_range(start, end); 465 return ret; 466 } 467 468 static int add_pagetable(unsigned long start, unsigned long end, bool direct) 469 { 470 return modify_pagetable(start, end, true, direct); 471 } 472 473 static int remove_pagetable(unsigned long start, unsigned long end, bool direct) 474 { 475 return modify_pagetable(start, end, false, direct); 476 } 477 478 /* 479 * Add a physical memory range to the 1:1 mapping. 480 */ 481 static int vmem_add_range(unsigned long start, unsigned long size) 482 { 483 return add_pagetable(start, start + size, true); 484 } 485 486 /* 487 * Remove a physical memory range from the 1:1 mapping. 488 */ 489 static void vmem_remove_range(unsigned long start, unsigned long size) 490 { 491 remove_pagetable(start, start + size, true); 492 } 493 494 /* 495 * Add a backed mem_map array to the virtual mem_map array. 496 */ 497 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node, 498 struct vmem_altmap *altmap) 499 { 500 int ret; 501 502 mutex_lock(&vmem_mutex); 503 /* We don't care about the node, just use NUMA_NO_NODE on allocations */ 504 ret = add_pagetable(start, end, false); 505 if (ret) 506 remove_pagetable(start, end, false); 507 mutex_unlock(&vmem_mutex); 508 return ret; 509 } 510 511 void vmemmap_free(unsigned long start, unsigned long end, 512 struct vmem_altmap *altmap) 513 { 514 mutex_lock(&vmem_mutex); 515 remove_pagetable(start, end, false); 516 mutex_unlock(&vmem_mutex); 517 } 518 519 void vmem_remove_mapping(unsigned long start, unsigned long size) 520 { 521 mutex_lock(&vmem_mutex); 522 vmem_remove_range(start, size); 523 mutex_unlock(&vmem_mutex); 524 } 525 526 struct range arch_get_mappable_range(void) 527 { 528 struct range mhp_range; 529 530 mhp_range.start = 0; 531 mhp_range.end = VMEM_MAX_PHYS - 1; 532 return mhp_range; 533 } 534 535 int vmem_add_mapping(unsigned long start, unsigned long size) 536 { 537 struct range range = arch_get_mappable_range(); 538 int ret; 539 540 if (start < range.start || 541 start + size > range.end + 1 || 542 start + size < start) 543 return -ERANGE; 544 545 mutex_lock(&vmem_mutex); 546 ret = vmem_add_range(start, size); 547 if (ret) 548 vmem_remove_range(start, size); 549 mutex_unlock(&vmem_mutex); 550 return ret; 551 } 552 553 /* 554 * Allocate new or return existing page-table entry, but do not map it 555 * to any physical address. If missing, allocate segment- and region- 556 * table entries along. Meeting a large segment- or region-table entry 557 * while traversing is an error, since the function is expected to be 558 * called against virtual regions reserverd for 4KB mappings only. 559 */ 560 pte_t *vmem_get_alloc_pte(unsigned long addr, bool alloc) 561 { 562 pte_t *ptep = NULL; 563 pgd_t *pgd; 564 p4d_t *p4d; 565 pud_t *pud; 566 pmd_t *pmd; 567 pte_t *pte; 568 569 pgd = pgd_offset_k(addr); 570 if (pgd_none(*pgd)) { 571 if (!alloc) 572 goto out; 573 p4d = vmem_crst_alloc(_REGION2_ENTRY_EMPTY); 574 if (!p4d) 575 goto out; 576 pgd_populate(&init_mm, pgd, p4d); 577 } 578 p4d = p4d_offset(pgd, addr); 579 if (p4d_none(*p4d)) { 580 if (!alloc) 581 goto out; 582 pud = vmem_crst_alloc(_REGION3_ENTRY_EMPTY); 583 if (!pud) 584 goto out; 585 p4d_populate(&init_mm, p4d, pud); 586 } 587 pud = pud_offset(p4d, addr); 588 if (pud_none(*pud)) { 589 if (!alloc) 590 goto out; 591 pmd = vmem_crst_alloc(_SEGMENT_ENTRY_EMPTY); 592 if (!pmd) 593 goto out; 594 pud_populate(&init_mm, pud, pmd); 595 } else if (WARN_ON_ONCE(pud_large(*pud))) { 596 goto out; 597 } 598 pmd = pmd_offset(pud, addr); 599 if (pmd_none(*pmd)) { 600 if (!alloc) 601 goto out; 602 pte = vmem_pte_alloc(); 603 if (!pte) 604 goto out; 605 pmd_populate(&init_mm, pmd, pte); 606 } else if (WARN_ON_ONCE(pmd_large(*pmd))) { 607 goto out; 608 } 609 ptep = pte_offset_kernel(pmd, addr); 610 out: 611 return ptep; 612 } 613 614 int __vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot, bool alloc) 615 { 616 pte_t *ptep, pte; 617 618 if (!IS_ALIGNED(addr, PAGE_SIZE)) 619 return -EINVAL; 620 ptep = vmem_get_alloc_pte(addr, alloc); 621 if (!ptep) 622 return -ENOMEM; 623 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL); 624 pte = mk_pte_phys(phys, prot); 625 set_pte(ptep, pte); 626 return 0; 627 } 628 629 int vmem_map_4k_page(unsigned long addr, unsigned long phys, pgprot_t prot) 630 { 631 int rc; 632 633 mutex_lock(&vmem_mutex); 634 rc = __vmem_map_4k_page(addr, phys, prot, true); 635 mutex_unlock(&vmem_mutex); 636 return rc; 637 } 638 639 void vmem_unmap_4k_page(unsigned long addr) 640 { 641 pte_t *ptep; 642 643 mutex_lock(&vmem_mutex); 644 ptep = virt_to_kpte(addr); 645 __ptep_ipte(addr, ptep, 0, 0, IPTE_GLOBAL); 646 pte_clear(&init_mm, addr, ptep); 647 mutex_unlock(&vmem_mutex); 648 } 649 650 static int __init memblock_region_cmp(const void *a, const void *b) 651 { 652 const struct memblock_region *r1 = a; 653 const struct memblock_region *r2 = b; 654 655 if (r1->base < r2->base) 656 return -1; 657 if (r1->base > r2->base) 658 return 1; 659 return 0; 660 } 661 662 static void __init memblock_region_swap(void *a, void *b, int size) 663 { 664 swap(*(struct memblock_region *)a, *(struct memblock_region *)b); 665 } 666 667 /* 668 * map whole physical memory to virtual memory (identity mapping) 669 * we reserve enough space in the vmalloc area for vmemmap to hotplug 670 * additional memory segments. 671 */ 672 void __init vmem_map_init(void) 673 { 674 struct memblock_region memory_rwx_regions[] = { 675 { 676 .base = 0, 677 .size = sizeof(struct lowcore), 678 .flags = MEMBLOCK_NONE, 679 #ifdef CONFIG_NUMA 680 .nid = NUMA_NO_NODE, 681 #endif 682 }, 683 { 684 .base = __pa(_stext), 685 .size = _etext - _stext, 686 .flags = MEMBLOCK_NONE, 687 #ifdef CONFIG_NUMA 688 .nid = NUMA_NO_NODE, 689 #endif 690 }, 691 { 692 .base = __pa(_sinittext), 693 .size = _einittext - _sinittext, 694 .flags = MEMBLOCK_NONE, 695 #ifdef CONFIG_NUMA 696 .nid = NUMA_NO_NODE, 697 #endif 698 }, 699 { 700 .base = __stext_amode31, 701 .size = __etext_amode31 - __stext_amode31, 702 .flags = MEMBLOCK_NONE, 703 #ifdef CONFIG_NUMA 704 .nid = NUMA_NO_NODE, 705 #endif 706 }, 707 }; 708 struct memblock_type memory_rwx = { 709 .regions = memory_rwx_regions, 710 .cnt = ARRAY_SIZE(memory_rwx_regions), 711 .max = ARRAY_SIZE(memory_rwx_regions), 712 }; 713 phys_addr_t base, end; 714 u64 i; 715 716 /* 717 * Set RW+NX attribute on all memory, except regions enumerated with 718 * memory_rwx exclude type. These regions need different attributes, 719 * which are enforced afterwards. 720 * 721 * __for_each_mem_range() iterate and exclude types should be sorted. 722 * The relative location of _stext and _sinittext is hardcoded in the 723 * linker script. However a location of __stext_amode31 and the kernel 724 * image itself are chosen dynamically. Thus, sort the exclude type. 725 */ 726 sort(&memory_rwx_regions, 727 ARRAY_SIZE(memory_rwx_regions), sizeof(memory_rwx_regions[0]), 728 memblock_region_cmp, memblock_region_swap); 729 __for_each_mem_range(i, &memblock.memory, &memory_rwx, 730 NUMA_NO_NODE, MEMBLOCK_NONE, &base, &end, NULL) { 731 __set_memory((unsigned long)__va(base), 732 (end - base) >> PAGE_SHIFT, 733 SET_MEMORY_RW | SET_MEMORY_NX); 734 } 735 736 __set_memory((unsigned long)_stext, 737 (unsigned long)(_etext - _stext) >> PAGE_SHIFT, 738 SET_MEMORY_RO | SET_MEMORY_X); 739 __set_memory((unsigned long)_etext, 740 (unsigned long)(__end_rodata - _etext) >> PAGE_SHIFT, 741 SET_MEMORY_RO); 742 __set_memory((unsigned long)_sinittext, 743 (unsigned long)(_einittext - _sinittext) >> PAGE_SHIFT, 744 SET_MEMORY_RO | SET_MEMORY_X); 745 __set_memory(__stext_amode31, 746 (__etext_amode31 - __stext_amode31) >> PAGE_SHIFT, 747 SET_MEMORY_RO | SET_MEMORY_X); 748 749 /* lowcore must be executable for LPSWE */ 750 if (static_key_enabled(&cpu_has_bear)) 751 set_memory_nx(0, 1); 752 set_memory_nx(PAGE_SIZE, 1); 753 754 pr_info("Write protected kernel read-only data: %luk\n", 755 (unsigned long)(__end_rodata - _stext) >> 10); 756 } 757