1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright 2002 Andi Kleen, SuSE Labs. 4 * Thanks to Ben LaHaise for precious feedback. 5 */ 6#include <linux/highmem.h> 7#include <linux/memblock.h> 8#include <linux/sched.h> 9#include <linux/mm.h> 10#include <linux/interrupt.h> 11#include <linux/seq_file.h> 12#include <linux/proc_fs.h> 13#include <linux/debugfs.h> 14#include <linux/pfn.h> 15#include <linux/percpu.h> 16#include <linux/gfp.h> 17#include <linux/pci.h> 18#include <linux/vmalloc.h> 19#include <linux/libnvdimm.h> 20#include <linux/vmstat.h> 21#include <linux/kernel.h> 22#include <linux/cc_platform.h> 23#include <linux/set_memory.h> 24#include <linux/memregion.h> 25 26#include <asm/e820/api.h> 27#include <asm/processor.h> 28#include <asm/tlbflush.h> 29#include <asm/sections.h> 30#include <asm/setup.h> 31#include <linux/uaccess.h> 32#include <asm/pgalloc.h> 33#include <asm/proto.h> 34#include <asm/memtype.h> 35#include <asm/hyperv-tlfs.h> 36#include <asm/mshyperv.h> 37 38#include "../mm_internal.h" 39 40/* 41 * The current flushing context - we pass it instead of 5 arguments: 42 */ 43struct cpa_data { 44 unsigned long *vaddr; 45 pgd_t *pgd; 46 pgprot_t mask_set; 47 pgprot_t mask_clr; 48 unsigned long numpages; 49 unsigned long curpage; 50 unsigned long pfn; 51 unsigned int flags; 52 unsigned int force_split : 1, 53 force_static_prot : 1, 54 force_flush_all : 1; 55 struct page **pages; 56}; 57 58enum cpa_warn { 59 CPA_CONFLICT, 60 CPA_PROTECT, 61 CPA_DETECT, 62}; 63 64static const int cpa_warn_level = CPA_PROTECT; 65 66/* 67 * Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings) 68 * using cpa_lock. So that we don't allow any other cpu, with stale large tlb 69 * entries change the page attribute in parallel to some other cpu 70 * splitting a large page entry along with changing the attribute. 71 */ 72static DEFINE_SPINLOCK(cpa_lock); 73 74#define CPA_FLUSHTLB 1 75#define CPA_ARRAY 2 76#define CPA_PAGES_ARRAY 4 77#define CPA_NO_CHECK_ALIAS 8 /* Do not search for aliases */ 78 79static inline pgprot_t cachemode2pgprot(enum page_cache_mode pcm) 80{ 81 return __pgprot(cachemode2protval(pcm)); 82} 83 84#ifdef CONFIG_PROC_FS 85static unsigned long direct_pages_count[PG_LEVEL_NUM]; 86 87void update_page_count(int level, unsigned long pages) 88{ 89 /* Protect against CPA */ 90 spin_lock(&pgd_lock); 91 direct_pages_count[level] += pages; 92 spin_unlock(&pgd_lock); 93} 94 95static void split_page_count(int level) 96{ 97 if (direct_pages_count[level] == 0) 98 return; 99 100 direct_pages_count[level]--; 101 if (system_state == SYSTEM_RUNNING) { 102 if (level == PG_LEVEL_2M) 103 count_vm_event(DIRECT_MAP_LEVEL2_SPLIT); 104 else if (level == PG_LEVEL_1G) 105 count_vm_event(DIRECT_MAP_LEVEL3_SPLIT); 106 } 107 direct_pages_count[level - 1] += PTRS_PER_PTE; 108} 109 110void arch_report_meminfo(struct seq_file *m) 111{ 112 seq_printf(m, "DirectMap4k: %8lu kB\n", 113 direct_pages_count[PG_LEVEL_4K] << 2); 114#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) 115 seq_printf(m, "DirectMap2M: %8lu kB\n", 116 direct_pages_count[PG_LEVEL_2M] << 11); 117#else 118 seq_printf(m, "DirectMap4M: %8lu kB\n", 119 direct_pages_count[PG_LEVEL_2M] << 12); 120#endif 121 if (direct_gbpages) 122 seq_printf(m, "DirectMap1G: %8lu kB\n", 123 direct_pages_count[PG_LEVEL_1G] << 20); 124} 125#else 126static inline void split_page_count(int level) { } 127#endif 128 129#ifdef CONFIG_X86_CPA_STATISTICS 130 131static unsigned long cpa_1g_checked; 132static unsigned long cpa_1g_sameprot; 133static unsigned long cpa_1g_preserved; 134static unsigned long cpa_2m_checked; 135static unsigned long cpa_2m_sameprot; 136static unsigned long cpa_2m_preserved; 137static unsigned long cpa_4k_install; 138 139static inline void cpa_inc_1g_checked(void) 140{ 141 cpa_1g_checked++; 142} 143 144static inline void cpa_inc_2m_checked(void) 145{ 146 cpa_2m_checked++; 147} 148 149static inline void cpa_inc_4k_install(void) 150{ 151 data_race(cpa_4k_install++); 152} 153 154static inline void cpa_inc_lp_sameprot(int level) 155{ 156 if (level == PG_LEVEL_1G) 157 cpa_1g_sameprot++; 158 else 159 cpa_2m_sameprot++; 160} 161 162static inline void cpa_inc_lp_preserved(int level) 163{ 164 if (level == PG_LEVEL_1G) 165 cpa_1g_preserved++; 166 else 167 cpa_2m_preserved++; 168} 169 170static int cpastats_show(struct seq_file *m, void *p) 171{ 172 seq_printf(m, "1G pages checked: %16lu\n", cpa_1g_checked); 173 seq_printf(m, "1G pages sameprot: %16lu\n", cpa_1g_sameprot); 174 seq_printf(m, "1G pages preserved: %16lu\n", cpa_1g_preserved); 175 seq_printf(m, "2M pages checked: %16lu\n", cpa_2m_checked); 176 seq_printf(m, "2M pages sameprot: %16lu\n", cpa_2m_sameprot); 177 seq_printf(m, "2M pages preserved: %16lu\n", cpa_2m_preserved); 178 seq_printf(m, "4K pages set-checked: %16lu\n", cpa_4k_install); 179 return 0; 180} 181 182static int cpastats_open(struct inode *inode, struct file *file) 183{ 184 return single_open(file, cpastats_show, NULL); 185} 186 187static const struct file_operations cpastats_fops = { 188 .open = cpastats_open, 189 .read = seq_read, 190 .llseek = seq_lseek, 191 .release = single_release, 192}; 193 194static int __init cpa_stats_init(void) 195{ 196 debugfs_create_file("cpa_stats", S_IRUSR, arch_debugfs_dir, NULL, 197 &cpastats_fops); 198 return 0; 199} 200late_initcall(cpa_stats_init); 201#else 202static inline void cpa_inc_1g_checked(void) { } 203static inline void cpa_inc_2m_checked(void) { } 204static inline void cpa_inc_4k_install(void) { } 205static inline void cpa_inc_lp_sameprot(int level) { } 206static inline void cpa_inc_lp_preserved(int level) { } 207#endif 208 209 210static inline int 211within(unsigned long addr, unsigned long start, unsigned long end) 212{ 213 return addr >= start && addr < end; 214} 215 216static inline int 217within_inclusive(unsigned long addr, unsigned long start, unsigned long end) 218{ 219 return addr >= start && addr <= end; 220} 221 222#ifdef CONFIG_X86_64 223 224/* 225 * The kernel image is mapped into two places in the virtual address space 226 * (addresses without KASLR, of course): 227 * 228 * 1. The kernel direct map (0xffff880000000000) 229 * 2. The "high kernel map" (0xffffffff81000000) 230 * 231 * We actually execute out of #2. If we get the address of a kernel symbol, it 232 * points to #2, but almost all physical-to-virtual translations point to #1. 233 * 234 * This is so that we can have both a directmap of all physical memory *and* 235 * take full advantage of the limited (s32) immediate addressing range (2G) 236 * of x86_64. 237 * 238 * See Documentation/arch/x86/x86_64/mm.rst for more detail. 239 */ 240 241static inline unsigned long highmap_start_pfn(void) 242{ 243 return __pa_symbol(_text) >> PAGE_SHIFT; 244} 245 246static inline unsigned long highmap_end_pfn(void) 247{ 248 /* Do not reference physical address outside the kernel. */ 249 return __pa_symbol(roundup(_brk_end, PMD_SIZE) - 1) >> PAGE_SHIFT; 250} 251 252static bool __cpa_pfn_in_highmap(unsigned long pfn) 253{ 254 /* 255 * Kernel text has an alias mapping at a high address, known 256 * here as "highmap". 257 */ 258 return within_inclusive(pfn, highmap_start_pfn(), highmap_end_pfn()); 259} 260 261#else 262 263static bool __cpa_pfn_in_highmap(unsigned long pfn) 264{ 265 /* There is no highmap on 32-bit */ 266 return false; 267} 268 269#endif 270 271/* 272 * See set_mce_nospec(). 273 * 274 * Machine check recovery code needs to change cache mode of poisoned pages to 275 * UC to avoid speculative access logging another error. But passing the 276 * address of the 1:1 mapping to set_memory_uc() is a fine way to encourage a 277 * speculative access. So we cheat and flip the top bit of the address. This 278 * works fine for the code that updates the page tables. But at the end of the 279 * process we need to flush the TLB and cache and the non-canonical address 280 * causes a #GP fault when used by the INVLPG and CLFLUSH instructions. 281 * 282 * But in the common case we already have a canonical address. This code 283 * will fix the top bit if needed and is a no-op otherwise. 284 */ 285static inline unsigned long fix_addr(unsigned long addr) 286{ 287#ifdef CONFIG_X86_64 288 return (long)(addr << 1) >> 1; 289#else 290 return addr; 291#endif 292} 293 294static unsigned long __cpa_addr(struct cpa_data *cpa, unsigned long idx) 295{ 296 if (cpa->flags & CPA_PAGES_ARRAY) { 297 struct page *page = cpa->pages[idx]; 298 299 if (unlikely(PageHighMem(page))) 300 return 0; 301 302 return (unsigned long)page_address(page); 303 } 304 305 if (cpa->flags & CPA_ARRAY) 306 return cpa->vaddr[idx]; 307 308 return *cpa->vaddr + idx * PAGE_SIZE; 309} 310 311/* 312 * Flushing functions 313 */ 314 315static void clflush_cache_range_opt(void *vaddr, unsigned int size) 316{ 317 const unsigned long clflush_size = boot_cpu_data.x86_clflush_size; 318 void *p = (void *)((unsigned long)vaddr & ~(clflush_size - 1)); 319 void *vend = vaddr + size; 320 321 if (p >= vend) 322 return; 323 324 for (; p < vend; p += clflush_size) 325 clflushopt(p); 326} 327 328/** 329 * clflush_cache_range - flush a cache range with clflush 330 * @vaddr: virtual start address 331 * @size: number of bytes to flush 332 * 333 * CLFLUSHOPT is an unordered instruction which needs fencing with MFENCE or 334 * SFENCE to avoid ordering issues. 335 */ 336void clflush_cache_range(void *vaddr, unsigned int size) 337{ 338 mb(); 339 clflush_cache_range_opt(vaddr, size); 340 mb(); 341} 342EXPORT_SYMBOL_GPL(clflush_cache_range); 343 344#ifdef CONFIG_ARCH_HAS_PMEM_API 345void arch_invalidate_pmem(void *addr, size_t size) 346{ 347 clflush_cache_range(addr, size); 348} 349EXPORT_SYMBOL_GPL(arch_invalidate_pmem); 350#endif 351 352#ifdef CONFIG_ARCH_HAS_CPU_CACHE_INVALIDATE_MEMREGION 353bool cpu_cache_has_invalidate_memregion(void) 354{ 355 return !cpu_feature_enabled(X86_FEATURE_HYPERVISOR); 356} 357EXPORT_SYMBOL_NS_GPL(cpu_cache_has_invalidate_memregion, DEVMEM); 358 359int cpu_cache_invalidate_memregion(int res_desc) 360{ 361 if (WARN_ON_ONCE(!cpu_cache_has_invalidate_memregion())) 362 return -ENXIO; 363 wbinvd_on_all_cpus(); 364 return 0; 365} 366EXPORT_SYMBOL_NS_GPL(cpu_cache_invalidate_memregion, DEVMEM); 367#endif 368 369static void __cpa_flush_all(void *arg) 370{ 371 unsigned long cache = (unsigned long)arg; 372 373 /* 374 * Flush all to work around Errata in early athlons regarding 375 * large page flushing. 376 */ 377 __flush_tlb_all(); 378 379 if (cache && boot_cpu_data.x86 >= 4) 380 wbinvd(); 381} 382 383static void cpa_flush_all(unsigned long cache) 384{ 385 BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); 386 387 on_each_cpu(__cpa_flush_all, (void *) cache, 1); 388} 389 390static void __cpa_flush_tlb(void *data) 391{ 392 struct cpa_data *cpa = data; 393 unsigned int i; 394 395 for (i = 0; i < cpa->numpages; i++) 396 flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa, i))); 397} 398 399static void cpa_flush(struct cpa_data *data, int cache) 400{ 401 struct cpa_data *cpa = data; 402 unsigned int i; 403 404 BUG_ON(irqs_disabled() && !early_boot_irqs_disabled); 405 406 if (cache && !static_cpu_has(X86_FEATURE_CLFLUSH)) { 407 cpa_flush_all(cache); 408 return; 409 } 410 411 if (cpa->force_flush_all || cpa->numpages > tlb_single_page_flush_ceiling) 412 flush_tlb_all(); 413 else 414 on_each_cpu(__cpa_flush_tlb, cpa, 1); 415 416 if (!cache) 417 return; 418 419 mb(); 420 for (i = 0; i < cpa->numpages; i++) { 421 unsigned long addr = __cpa_addr(cpa, i); 422 unsigned int level; 423 424 pte_t *pte = lookup_address(addr, &level); 425 426 /* 427 * Only flush present addresses: 428 */ 429 if (pte && (pte_val(*pte) & _PAGE_PRESENT)) 430 clflush_cache_range_opt((void *)fix_addr(addr), PAGE_SIZE); 431 } 432 mb(); 433} 434 435static bool overlaps(unsigned long r1_start, unsigned long r1_end, 436 unsigned long r2_start, unsigned long r2_end) 437{ 438 return (r1_start <= r2_end && r1_end >= r2_start) || 439 (r2_start <= r1_end && r2_end >= r1_start); 440} 441 442#ifdef CONFIG_PCI_BIOS 443/* 444 * The BIOS area between 640k and 1Mb needs to be executable for PCI BIOS 445 * based config access (CONFIG_PCI_GOBIOS) support. 446 */ 447#define BIOS_PFN PFN_DOWN(BIOS_BEGIN) 448#define BIOS_PFN_END PFN_DOWN(BIOS_END - 1) 449 450static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn) 451{ 452 if (pcibios_enabled && overlaps(spfn, epfn, BIOS_PFN, BIOS_PFN_END)) 453 return _PAGE_NX; 454 return 0; 455} 456#else 457static pgprotval_t protect_pci_bios(unsigned long spfn, unsigned long epfn) 458{ 459 return 0; 460} 461#endif 462 463/* 464 * The .rodata section needs to be read-only. Using the pfn catches all 465 * aliases. This also includes __ro_after_init, so do not enforce until 466 * kernel_set_to_readonly is true. 467 */ 468static pgprotval_t protect_rodata(unsigned long spfn, unsigned long epfn) 469{ 470 unsigned long epfn_ro, spfn_ro = PFN_DOWN(__pa_symbol(__start_rodata)); 471 472 /* 473 * Note: __end_rodata is at page aligned and not inclusive, so 474 * subtract 1 to get the last enforced PFN in the rodata area. 475 */ 476 epfn_ro = PFN_DOWN(__pa_symbol(__end_rodata)) - 1; 477 478 if (kernel_set_to_readonly && overlaps(spfn, epfn, spfn_ro, epfn_ro)) 479 return _PAGE_RW; 480 return 0; 481} 482 483/* 484 * Protect kernel text against becoming non executable by forbidding 485 * _PAGE_NX. This protects only the high kernel mapping (_text -> _etext) 486 * out of which the kernel actually executes. Do not protect the low 487 * mapping. 488 * 489 * This does not cover __inittext since that is gone after boot. 490 */ 491static pgprotval_t protect_kernel_text(unsigned long start, unsigned long end) 492{ 493 unsigned long t_end = (unsigned long)_etext - 1; 494 unsigned long t_start = (unsigned long)_text; 495 496 if (overlaps(start, end, t_start, t_end)) 497 return _PAGE_NX; 498 return 0; 499} 500 501#if defined(CONFIG_X86_64) 502/* 503 * Once the kernel maps the text as RO (kernel_set_to_readonly is set), 504 * kernel text mappings for the large page aligned text, rodata sections 505 * will be always read-only. For the kernel identity mappings covering the 506 * holes caused by this alignment can be anything that user asks. 507 * 508 * This will preserve the large page mappings for kernel text/data at no 509 * extra cost. 510 */ 511static pgprotval_t protect_kernel_text_ro(unsigned long start, 512 unsigned long end) 513{ 514 unsigned long t_end = (unsigned long)__end_rodata_hpage_align - 1; 515 unsigned long t_start = (unsigned long)_text; 516 unsigned int level; 517 518 if (!kernel_set_to_readonly || !overlaps(start, end, t_start, t_end)) 519 return 0; 520 /* 521 * Don't enforce the !RW mapping for the kernel text mapping, if 522 * the current mapping is already using small page mapping. No 523 * need to work hard to preserve large page mappings in this case. 524 * 525 * This also fixes the Linux Xen paravirt guest boot failure caused 526 * by unexpected read-only mappings for kernel identity 527 * mappings. In this paravirt guest case, the kernel text mapping 528 * and the kernel identity mapping share the same page-table pages, 529 * so the protections for kernel text and identity mappings have to 530 * be the same. 531 */ 532 if (lookup_address(start, &level) && (level != PG_LEVEL_4K)) 533 return _PAGE_RW; 534 return 0; 535} 536#else 537static pgprotval_t protect_kernel_text_ro(unsigned long start, 538 unsigned long end) 539{ 540 return 0; 541} 542#endif 543 544static inline bool conflicts(pgprot_t prot, pgprotval_t val) 545{ 546 return (pgprot_val(prot) & ~val) != pgprot_val(prot); 547} 548 549static inline void check_conflict(int warnlvl, pgprot_t prot, pgprotval_t val, 550 unsigned long start, unsigned long end, 551 unsigned long pfn, const char *txt) 552{ 553 static const char *lvltxt[] = { 554 [CPA_CONFLICT] = "conflict", 555 [CPA_PROTECT] = "protect", 556 [CPA_DETECT] = "detect", 557 }; 558 559 if (warnlvl > cpa_warn_level || !conflicts(prot, val)) 560 return; 561 562 pr_warn("CPA %8s %10s: 0x%016lx - 0x%016lx PFN %lx req %016llx prevent %016llx\n", 563 lvltxt[warnlvl], txt, start, end, pfn, (unsigned long long)pgprot_val(prot), 564 (unsigned long long)val); 565} 566 567/* 568 * Certain areas of memory on x86 require very specific protection flags, 569 * for example the BIOS area or kernel text. Callers don't always get this 570 * right (again, ioremap() on BIOS memory is not uncommon) so this function 571 * checks and fixes these known static required protection bits. 572 */ 573static inline pgprot_t static_protections(pgprot_t prot, unsigned long start, 574 unsigned long pfn, unsigned long npg, 575 unsigned long lpsize, int warnlvl) 576{ 577 pgprotval_t forbidden, res; 578 unsigned long end; 579 580 /* 581 * There is no point in checking RW/NX conflicts when the requested 582 * mapping is setting the page !PRESENT. 583 */ 584 if (!(pgprot_val(prot) & _PAGE_PRESENT)) 585 return prot; 586 587 /* Operate on the virtual address */ 588 end = start + npg * PAGE_SIZE - 1; 589 590 res = protect_kernel_text(start, end); 591 check_conflict(warnlvl, prot, res, start, end, pfn, "Text NX"); 592 forbidden = res; 593 594 /* 595 * Special case to preserve a large page. If the change spawns the 596 * full large page mapping then there is no point to split it 597 * up. Happens with ftrace and is going to be removed once ftrace 598 * switched to text_poke(). 599 */ 600 if (lpsize != (npg * PAGE_SIZE) || (start & (lpsize - 1))) { 601 res = protect_kernel_text_ro(start, end); 602 check_conflict(warnlvl, prot, res, start, end, pfn, "Text RO"); 603 forbidden |= res; 604 } 605 606 /* Check the PFN directly */ 607 res = protect_pci_bios(pfn, pfn + npg - 1); 608 check_conflict(warnlvl, prot, res, start, end, pfn, "PCIBIOS NX"); 609 forbidden |= res; 610 611 res = protect_rodata(pfn, pfn + npg - 1); 612 check_conflict(warnlvl, prot, res, start, end, pfn, "Rodata RO"); 613 forbidden |= res; 614 615 return __pgprot(pgprot_val(prot) & ~forbidden); 616} 617 618/* 619 * Validate strict W^X semantics. 620 */ 621static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long start, 622 unsigned long pfn, unsigned long npg) 623{ 624 unsigned long end; 625 626 /* 627 * 32-bit has some unfixable W+X issues, like EFI code 628 * and writeable data being in the same page. Disable 629 * detection and enforcement there. 630 */ 631 if (IS_ENABLED(CONFIG_X86_32)) 632 return new; 633 634 /* Only verify when NX is supported: */ 635 if (!(__supported_pte_mask & _PAGE_NX)) 636 return new; 637 638 if (!((pgprot_val(old) ^ pgprot_val(new)) & (_PAGE_RW | _PAGE_NX))) 639 return new; 640 641 if ((pgprot_val(new) & (_PAGE_RW | _PAGE_NX)) != _PAGE_RW) 642 return new; 643 644 end = start + npg * PAGE_SIZE - 1; 645 WARN_ONCE(1, "CPA detected W^X violation: %016llx -> %016llx range: 0x%016lx - 0x%016lx PFN %lx\n", 646 (unsigned long long)pgprot_val(old), 647 (unsigned long long)pgprot_val(new), 648 start, end, pfn); 649 650 /* 651 * For now, allow all permission change attempts by returning the 652 * attempted permissions. This can 'return old' to actively 653 * refuse the permission change at a later time. 654 */ 655 return new; 656} 657 658/* 659 * Lookup the page table entry for a virtual address in a specific pgd. 660 * Return a pointer to the entry and the level of the mapping. 661 */ 662pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, 663 unsigned int *level) 664{ 665 p4d_t *p4d; 666 pud_t *pud; 667 pmd_t *pmd; 668 669 *level = PG_LEVEL_NONE; 670 671 if (pgd_none(*pgd)) 672 return NULL; 673 674 p4d = p4d_offset(pgd, address); 675 if (p4d_none(*p4d)) 676 return NULL; 677 678 *level = PG_LEVEL_512G; 679 if (p4d_leaf(*p4d) || !p4d_present(*p4d)) 680 return (pte_t *)p4d; 681 682 pud = pud_offset(p4d, address); 683 if (pud_none(*pud)) 684 return NULL; 685 686 *level = PG_LEVEL_1G; 687 if (pud_leaf(*pud) || !pud_present(*pud)) 688 return (pte_t *)pud; 689 690 pmd = pmd_offset(pud, address); 691 if (pmd_none(*pmd)) 692 return NULL; 693 694 *level = PG_LEVEL_2M; 695 if (pmd_leaf(*pmd) || !pmd_present(*pmd)) 696 return (pte_t *)pmd; 697 698 *level = PG_LEVEL_4K; 699 700 return pte_offset_kernel(pmd, address); 701} 702 703/* 704 * Lookup the page table entry for a virtual address. Return a pointer 705 * to the entry and the level of the mapping. 706 * 707 * Note: We return pud and pmd either when the entry is marked large 708 * or when the present bit is not set. Otherwise we would return a 709 * pointer to a nonexisting mapping. 710 */ 711pte_t *lookup_address(unsigned long address, unsigned int *level) 712{ 713 return lookup_address_in_pgd(pgd_offset_k(address), address, level); 714} 715EXPORT_SYMBOL_GPL(lookup_address); 716 717static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address, 718 unsigned int *level) 719{ 720 if (cpa->pgd) 721 return lookup_address_in_pgd(cpa->pgd + pgd_index(address), 722 address, level); 723 724 return lookup_address(address, level); 725} 726 727/* 728 * Lookup the PMD entry for a virtual address. Return a pointer to the entry 729 * or NULL if not present. 730 */ 731pmd_t *lookup_pmd_address(unsigned long address) 732{ 733 pgd_t *pgd; 734 p4d_t *p4d; 735 pud_t *pud; 736 737 pgd = pgd_offset_k(address); 738 if (pgd_none(*pgd)) 739 return NULL; 740 741 p4d = p4d_offset(pgd, address); 742 if (p4d_none(*p4d) || p4d_leaf(*p4d) || !p4d_present(*p4d)) 743 return NULL; 744 745 pud = pud_offset(p4d, address); 746 if (pud_none(*pud) || pud_leaf(*pud) || !pud_present(*pud)) 747 return NULL; 748 749 return pmd_offset(pud, address); 750} 751 752/* 753 * This is necessary because __pa() does not work on some 754 * kinds of memory, like vmalloc() or the alloc_remap() 755 * areas on 32-bit NUMA systems. The percpu areas can 756 * end up in this kind of memory, for instance. 757 * 758 * Note that as long as the PTEs are well-formed with correct PFNs, this 759 * works without checking the PRESENT bit in the leaf PTE. This is unlike 760 * the similar vmalloc_to_page() and derivatives. Callers may depend on 761 * this behavior. 762 * 763 * This could be optimized, but it is only used in paths that are not perf 764 * sensitive, and keeping it unoptimized should increase the testing coverage 765 * for the more obscure platforms. 766 */ 767phys_addr_t slow_virt_to_phys(void *__virt_addr) 768{ 769 unsigned long virt_addr = (unsigned long)__virt_addr; 770 phys_addr_t phys_addr; 771 unsigned long offset; 772 enum pg_level level; 773 pte_t *pte; 774 775 pte = lookup_address(virt_addr, &level); 776 BUG_ON(!pte); 777 778 /* 779 * pXX_pfn() returns unsigned long, which must be cast to phys_addr_t 780 * before being left-shifted PAGE_SHIFT bits -- this trick is to 781 * make 32-PAE kernel work correctly. 782 */ 783 switch (level) { 784 case PG_LEVEL_1G: 785 phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT; 786 offset = virt_addr & ~PUD_MASK; 787 break; 788 case PG_LEVEL_2M: 789 phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT; 790 offset = virt_addr & ~PMD_MASK; 791 break; 792 default: 793 phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT; 794 offset = virt_addr & ~PAGE_MASK; 795 } 796 797 return (phys_addr_t)(phys_addr | offset); 798} 799EXPORT_SYMBOL_GPL(slow_virt_to_phys); 800 801/* 802 * Set the new pmd in all the pgds we know about: 803 */ 804static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) 805{ 806 /* change init_mm */ 807 set_pte_atomic(kpte, pte); 808#ifdef CONFIG_X86_32 809 if (!SHARED_KERNEL_PMD) { 810 struct page *page; 811 812 list_for_each_entry(page, &pgd_list, lru) { 813 pgd_t *pgd; 814 p4d_t *p4d; 815 pud_t *pud; 816 pmd_t *pmd; 817 818 pgd = (pgd_t *)page_address(page) + pgd_index(address); 819 p4d = p4d_offset(pgd, address); 820 pud = pud_offset(p4d, address); 821 pmd = pmd_offset(pud, address); 822 set_pte_atomic((pte_t *)pmd, pte); 823 } 824 } 825#endif 826} 827 828static pgprot_t pgprot_clear_protnone_bits(pgprot_t prot) 829{ 830 /* 831 * _PAGE_GLOBAL means "global page" for present PTEs. 832 * But, it is also used to indicate _PAGE_PROTNONE 833 * for non-present PTEs. 834 * 835 * This ensures that a _PAGE_GLOBAL PTE going from 836 * present to non-present is not confused as 837 * _PAGE_PROTNONE. 838 */ 839 if (!(pgprot_val(prot) & _PAGE_PRESENT)) 840 pgprot_val(prot) &= ~_PAGE_GLOBAL; 841 842 return prot; 843} 844 845static int __should_split_large_page(pte_t *kpte, unsigned long address, 846 struct cpa_data *cpa) 847{ 848 unsigned long numpages, pmask, psize, lpaddr, pfn, old_pfn; 849 pgprot_t old_prot, new_prot, req_prot, chk_prot; 850 pte_t new_pte, *tmp; 851 enum pg_level level; 852 853 /* 854 * Check for races, another CPU might have split this page 855 * up already: 856 */ 857 tmp = _lookup_address_cpa(cpa, address, &level); 858 if (tmp != kpte) 859 return 1; 860 861 switch (level) { 862 case PG_LEVEL_2M: 863 old_prot = pmd_pgprot(*(pmd_t *)kpte); 864 old_pfn = pmd_pfn(*(pmd_t *)kpte); 865 cpa_inc_2m_checked(); 866 break; 867 case PG_LEVEL_1G: 868 old_prot = pud_pgprot(*(pud_t *)kpte); 869 old_pfn = pud_pfn(*(pud_t *)kpte); 870 cpa_inc_1g_checked(); 871 break; 872 default: 873 return -EINVAL; 874 } 875 876 psize = page_level_size(level); 877 pmask = page_level_mask(level); 878 879 /* 880 * Calculate the number of pages, which fit into this large 881 * page starting at address: 882 */ 883 lpaddr = (address + psize) & pmask; 884 numpages = (lpaddr - address) >> PAGE_SHIFT; 885 if (numpages < cpa->numpages) 886 cpa->numpages = numpages; 887 888 /* 889 * We are safe now. Check whether the new pgprot is the same: 890 * Convert protection attributes to 4k-format, as cpa->mask* are set 891 * up accordingly. 892 */ 893 894 /* Clear PSE (aka _PAGE_PAT) and move PAT bit to correct position */ 895 req_prot = pgprot_large_2_4k(old_prot); 896 897 pgprot_val(req_prot) &= ~pgprot_val(cpa->mask_clr); 898 pgprot_val(req_prot) |= pgprot_val(cpa->mask_set); 899 900 /* 901 * req_prot is in format of 4k pages. It must be converted to large 902 * page format: the caching mode includes the PAT bit located at 903 * different bit positions in the two formats. 904 */ 905 req_prot = pgprot_4k_2_large(req_prot); 906 req_prot = pgprot_clear_protnone_bits(req_prot); 907 if (pgprot_val(req_prot) & _PAGE_PRESENT) 908 pgprot_val(req_prot) |= _PAGE_PSE; 909 910 /* 911 * old_pfn points to the large page base pfn. So we need to add the 912 * offset of the virtual address: 913 */ 914 pfn = old_pfn + ((address & (psize - 1)) >> PAGE_SHIFT); 915 cpa->pfn = pfn; 916 917 /* 918 * Calculate the large page base address and the number of 4K pages 919 * in the large page 920 */ 921 lpaddr = address & pmask; 922 numpages = psize >> PAGE_SHIFT; 923 924 /* 925 * Sanity check that the existing mapping is correct versus the static 926 * protections. static_protections() guards against !PRESENT, so no 927 * extra conditional required here. 928 */ 929 chk_prot = static_protections(old_prot, lpaddr, old_pfn, numpages, 930 psize, CPA_CONFLICT); 931 932 if (WARN_ON_ONCE(pgprot_val(chk_prot) != pgprot_val(old_prot))) { 933 /* 934 * Split the large page and tell the split code to 935 * enforce static protections. 936 */ 937 cpa->force_static_prot = 1; 938 return 1; 939 } 940 941 /* 942 * Optimization: If the requested pgprot is the same as the current 943 * pgprot, then the large page can be preserved and no updates are 944 * required independent of alignment and length of the requested 945 * range. The above already established that the current pgprot is 946 * correct, which in consequence makes the requested pgprot correct 947 * as well if it is the same. The static protection scan below will 948 * not come to a different conclusion. 949 */ 950 if (pgprot_val(req_prot) == pgprot_val(old_prot)) { 951 cpa_inc_lp_sameprot(level); 952 return 0; 953 } 954 955 /* 956 * If the requested range does not cover the full page, split it up 957 */ 958 if (address != lpaddr || cpa->numpages != numpages) 959 return 1; 960 961 /* 962 * Check whether the requested pgprot is conflicting with a static 963 * protection requirement in the large page. 964 */ 965 new_prot = static_protections(req_prot, lpaddr, old_pfn, numpages, 966 psize, CPA_DETECT); 967 968 new_prot = verify_rwx(old_prot, new_prot, lpaddr, old_pfn, numpages); 969 970 /* 971 * If there is a conflict, split the large page. 972 * 973 * There used to be a 4k wise evaluation trying really hard to 974 * preserve the large pages, but experimentation has shown, that this 975 * does not help at all. There might be corner cases which would 976 * preserve one large page occasionally, but it's really not worth the 977 * extra code and cycles for the common case. 978 */ 979 if (pgprot_val(req_prot) != pgprot_val(new_prot)) 980 return 1; 981 982 /* All checks passed. Update the large page mapping. */ 983 new_pte = pfn_pte(old_pfn, new_prot); 984 __set_pmd_pte(kpte, address, new_pte); 985 cpa->flags |= CPA_FLUSHTLB; 986 cpa_inc_lp_preserved(level); 987 return 0; 988} 989 990static int should_split_large_page(pte_t *kpte, unsigned long address, 991 struct cpa_data *cpa) 992{ 993 int do_split; 994 995 if (cpa->force_split) 996 return 1; 997 998 spin_lock(&pgd_lock); 999 do_split = __should_split_large_page(kpte, address, cpa); 1000 spin_unlock(&pgd_lock); 1001 1002 return do_split; 1003} 1004 1005static void split_set_pte(struct cpa_data *cpa, pte_t *pte, unsigned long pfn, 1006 pgprot_t ref_prot, unsigned long address, 1007 unsigned long size) 1008{ 1009 unsigned int npg = PFN_DOWN(size); 1010 pgprot_t prot; 1011 1012 /* 1013 * If should_split_large_page() discovered an inconsistent mapping, 1014 * remove the invalid protection in the split mapping. 1015 */ 1016 if (!cpa->force_static_prot) 1017 goto set; 1018 1019 /* Hand in lpsize = 0 to enforce the protection mechanism */ 1020 prot = static_protections(ref_prot, address, pfn, npg, 0, CPA_PROTECT); 1021 1022 if (pgprot_val(prot) == pgprot_val(ref_prot)) 1023 goto set; 1024 1025 /* 1026 * If this is splitting a PMD, fix it up. PUD splits cannot be 1027 * fixed trivially as that would require to rescan the newly 1028 * installed PMD mappings after returning from split_large_page() 1029 * so an eventual further split can allocate the necessary PTE 1030 * pages. Warn for now and revisit it in case this actually 1031 * happens. 1032 */ 1033 if (size == PAGE_SIZE) 1034 ref_prot = prot; 1035 else 1036 pr_warn_once("CPA: Cannot fixup static protections for PUD split\n"); 1037set: 1038 set_pte(pte, pfn_pte(pfn, ref_prot)); 1039} 1040 1041static int 1042__split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, 1043 struct page *base) 1044{ 1045 unsigned long lpaddr, lpinc, ref_pfn, pfn, pfninc = 1; 1046 pte_t *pbase = (pte_t *)page_address(base); 1047 unsigned int i, level; 1048 pgprot_t ref_prot; 1049 pte_t *tmp; 1050 1051 spin_lock(&pgd_lock); 1052 /* 1053 * Check for races, another CPU might have split this page 1054 * up for us already: 1055 */ 1056 tmp = _lookup_address_cpa(cpa, address, &level); 1057 if (tmp != kpte) { 1058 spin_unlock(&pgd_lock); 1059 return 1; 1060 } 1061 1062 paravirt_alloc_pte(&init_mm, page_to_pfn(base)); 1063 1064 switch (level) { 1065 case PG_LEVEL_2M: 1066 ref_prot = pmd_pgprot(*(pmd_t *)kpte); 1067 /* 1068 * Clear PSE (aka _PAGE_PAT) and move 1069 * PAT bit to correct position. 1070 */ 1071 ref_prot = pgprot_large_2_4k(ref_prot); 1072 ref_pfn = pmd_pfn(*(pmd_t *)kpte); 1073 lpaddr = address & PMD_MASK; 1074 lpinc = PAGE_SIZE; 1075 break; 1076 1077 case PG_LEVEL_1G: 1078 ref_prot = pud_pgprot(*(pud_t *)kpte); 1079 ref_pfn = pud_pfn(*(pud_t *)kpte); 1080 pfninc = PMD_SIZE >> PAGE_SHIFT; 1081 lpaddr = address & PUD_MASK; 1082 lpinc = PMD_SIZE; 1083 /* 1084 * Clear the PSE flags if the PRESENT flag is not set 1085 * otherwise pmd_present/pmd_huge will return true 1086 * even on a non present pmd. 1087 */ 1088 if (!(pgprot_val(ref_prot) & _PAGE_PRESENT)) 1089 pgprot_val(ref_prot) &= ~_PAGE_PSE; 1090 break; 1091 1092 default: 1093 spin_unlock(&pgd_lock); 1094 return 1; 1095 } 1096 1097 ref_prot = pgprot_clear_protnone_bits(ref_prot); 1098 1099 /* 1100 * Get the target pfn from the original entry: 1101 */ 1102 pfn = ref_pfn; 1103 for (i = 0; i < PTRS_PER_PTE; i++, pfn += pfninc, lpaddr += lpinc) 1104 split_set_pte(cpa, pbase + i, pfn, ref_prot, lpaddr, lpinc); 1105 1106 if (virt_addr_valid(address)) { 1107 unsigned long pfn = PFN_DOWN(__pa(address)); 1108 1109 if (pfn_range_is_mapped(pfn, pfn + 1)) 1110 split_page_count(level); 1111 } 1112 1113 /* 1114 * Install the new, split up pagetable. 1115 * 1116 * We use the standard kernel pagetable protections for the new 1117 * pagetable protections, the actual ptes set above control the 1118 * primary protection behavior: 1119 */ 1120 __set_pmd_pte(kpte, address, mk_pte(base, __pgprot(_KERNPG_TABLE))); 1121 1122 /* 1123 * Do a global flush tlb after splitting the large page 1124 * and before we do the actual change page attribute in the PTE. 1125 * 1126 * Without this, we violate the TLB application note, that says: 1127 * "The TLBs may contain both ordinary and large-page 1128 * translations for a 4-KByte range of linear addresses. This 1129 * may occur if software modifies the paging structures so that 1130 * the page size used for the address range changes. If the two 1131 * translations differ with respect to page frame or attributes 1132 * (e.g., permissions), processor behavior is undefined and may 1133 * be implementation-specific." 1134 * 1135 * We do this global tlb flush inside the cpa_lock, so that we 1136 * don't allow any other cpu, with stale tlb entries change the 1137 * page attribute in parallel, that also falls into the 1138 * just split large page entry. 1139 */ 1140 flush_tlb_all(); 1141 spin_unlock(&pgd_lock); 1142 1143 return 0; 1144} 1145 1146static int split_large_page(struct cpa_data *cpa, pte_t *kpte, 1147 unsigned long address) 1148{ 1149 struct page *base; 1150 1151 if (!debug_pagealloc_enabled()) 1152 spin_unlock(&cpa_lock); 1153 base = alloc_pages(GFP_KERNEL, 0); 1154 if (!debug_pagealloc_enabled()) 1155 spin_lock(&cpa_lock); 1156 if (!base) 1157 return -ENOMEM; 1158 1159 if (__split_large_page(cpa, kpte, address, base)) 1160 __free_page(base); 1161 1162 return 0; 1163} 1164 1165static bool try_to_free_pte_page(pte_t *pte) 1166{ 1167 int i; 1168 1169 for (i = 0; i < PTRS_PER_PTE; i++) 1170 if (!pte_none(pte[i])) 1171 return false; 1172 1173 free_page((unsigned long)pte); 1174 return true; 1175} 1176 1177static bool try_to_free_pmd_page(pmd_t *pmd) 1178{ 1179 int i; 1180 1181 for (i = 0; i < PTRS_PER_PMD; i++) 1182 if (!pmd_none(pmd[i])) 1183 return false; 1184 1185 free_page((unsigned long)pmd); 1186 return true; 1187} 1188 1189static bool unmap_pte_range(pmd_t *pmd, unsigned long start, unsigned long end) 1190{ 1191 pte_t *pte = pte_offset_kernel(pmd, start); 1192 1193 while (start < end) { 1194 set_pte(pte, __pte(0)); 1195 1196 start += PAGE_SIZE; 1197 pte++; 1198 } 1199 1200 if (try_to_free_pte_page((pte_t *)pmd_page_vaddr(*pmd))) { 1201 pmd_clear(pmd); 1202 return true; 1203 } 1204 return false; 1205} 1206 1207static void __unmap_pmd_range(pud_t *pud, pmd_t *pmd, 1208 unsigned long start, unsigned long end) 1209{ 1210 if (unmap_pte_range(pmd, start, end)) 1211 if (try_to_free_pmd_page(pud_pgtable(*pud))) 1212 pud_clear(pud); 1213} 1214 1215static void unmap_pmd_range(pud_t *pud, unsigned long start, unsigned long end) 1216{ 1217 pmd_t *pmd = pmd_offset(pud, start); 1218 1219 /* 1220 * Not on a 2MB page boundary? 1221 */ 1222 if (start & (PMD_SIZE - 1)) { 1223 unsigned long next_page = (start + PMD_SIZE) & PMD_MASK; 1224 unsigned long pre_end = min_t(unsigned long, end, next_page); 1225 1226 __unmap_pmd_range(pud, pmd, start, pre_end); 1227 1228 start = pre_end; 1229 pmd++; 1230 } 1231 1232 /* 1233 * Try to unmap in 2M chunks. 1234 */ 1235 while (end - start >= PMD_SIZE) { 1236 if (pmd_leaf(*pmd)) 1237 pmd_clear(pmd); 1238 else 1239 __unmap_pmd_range(pud, pmd, start, start + PMD_SIZE); 1240 1241 start += PMD_SIZE; 1242 pmd++; 1243 } 1244 1245 /* 1246 * 4K leftovers? 1247 */ 1248 if (start < end) 1249 return __unmap_pmd_range(pud, pmd, start, end); 1250 1251 /* 1252 * Try again to free the PMD page if haven't succeeded above. 1253 */ 1254 if (!pud_none(*pud)) 1255 if (try_to_free_pmd_page(pud_pgtable(*pud))) 1256 pud_clear(pud); 1257} 1258 1259static void unmap_pud_range(p4d_t *p4d, unsigned long start, unsigned long end) 1260{ 1261 pud_t *pud = pud_offset(p4d, start); 1262 1263 /* 1264 * Not on a GB page boundary? 1265 */ 1266 if (start & (PUD_SIZE - 1)) { 1267 unsigned long next_page = (start + PUD_SIZE) & PUD_MASK; 1268 unsigned long pre_end = min_t(unsigned long, end, next_page); 1269 1270 unmap_pmd_range(pud, start, pre_end); 1271 1272 start = pre_end; 1273 pud++; 1274 } 1275 1276 /* 1277 * Try to unmap in 1G chunks? 1278 */ 1279 while (end - start >= PUD_SIZE) { 1280 1281 if (pud_leaf(*pud)) 1282 pud_clear(pud); 1283 else 1284 unmap_pmd_range(pud, start, start + PUD_SIZE); 1285 1286 start += PUD_SIZE; 1287 pud++; 1288 } 1289 1290 /* 1291 * 2M leftovers? 1292 */ 1293 if (start < end) 1294 unmap_pmd_range(pud, start, end); 1295 1296 /* 1297 * No need to try to free the PUD page because we'll free it in 1298 * populate_pgd's error path 1299 */ 1300} 1301 1302static int alloc_pte_page(pmd_t *pmd) 1303{ 1304 pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL); 1305 if (!pte) 1306 return -1; 1307 1308 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE)); 1309 return 0; 1310} 1311 1312static int alloc_pmd_page(pud_t *pud) 1313{ 1314 pmd_t *pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL); 1315 if (!pmd) 1316 return -1; 1317 1318 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE)); 1319 return 0; 1320} 1321 1322static void populate_pte(struct cpa_data *cpa, 1323 unsigned long start, unsigned long end, 1324 unsigned num_pages, pmd_t *pmd, pgprot_t pgprot) 1325{ 1326 pte_t *pte; 1327 1328 pte = pte_offset_kernel(pmd, start); 1329 1330 pgprot = pgprot_clear_protnone_bits(pgprot); 1331 1332 while (num_pages-- && start < end) { 1333 set_pte(pte, pfn_pte(cpa->pfn, pgprot)); 1334 1335 start += PAGE_SIZE; 1336 cpa->pfn++; 1337 pte++; 1338 } 1339} 1340 1341static long populate_pmd(struct cpa_data *cpa, 1342 unsigned long start, unsigned long end, 1343 unsigned num_pages, pud_t *pud, pgprot_t pgprot) 1344{ 1345 long cur_pages = 0; 1346 pmd_t *pmd; 1347 pgprot_t pmd_pgprot; 1348 1349 /* 1350 * Not on a 2M boundary? 1351 */ 1352 if (start & (PMD_SIZE - 1)) { 1353 unsigned long pre_end = start + (num_pages << PAGE_SHIFT); 1354 unsigned long next_page = (start + PMD_SIZE) & PMD_MASK; 1355 1356 pre_end = min_t(unsigned long, pre_end, next_page); 1357 cur_pages = (pre_end - start) >> PAGE_SHIFT; 1358 cur_pages = min_t(unsigned int, num_pages, cur_pages); 1359 1360 /* 1361 * Need a PTE page? 1362 */ 1363 pmd = pmd_offset(pud, start); 1364 if (pmd_none(*pmd)) 1365 if (alloc_pte_page(pmd)) 1366 return -1; 1367 1368 populate_pte(cpa, start, pre_end, cur_pages, pmd, pgprot); 1369 1370 start = pre_end; 1371 } 1372 1373 /* 1374 * We mapped them all? 1375 */ 1376 if (num_pages == cur_pages) 1377 return cur_pages; 1378 1379 pmd_pgprot = pgprot_4k_2_large(pgprot); 1380 1381 while (end - start >= PMD_SIZE) { 1382 1383 /* 1384 * We cannot use a 1G page so allocate a PMD page if needed. 1385 */ 1386 if (pud_none(*pud)) 1387 if (alloc_pmd_page(pud)) 1388 return -1; 1389 1390 pmd = pmd_offset(pud, start); 1391 1392 set_pmd(pmd, pmd_mkhuge(pfn_pmd(cpa->pfn, 1393 canon_pgprot(pmd_pgprot)))); 1394 1395 start += PMD_SIZE; 1396 cpa->pfn += PMD_SIZE >> PAGE_SHIFT; 1397 cur_pages += PMD_SIZE >> PAGE_SHIFT; 1398 } 1399 1400 /* 1401 * Map trailing 4K pages. 1402 */ 1403 if (start < end) { 1404 pmd = pmd_offset(pud, start); 1405 if (pmd_none(*pmd)) 1406 if (alloc_pte_page(pmd)) 1407 return -1; 1408 1409 populate_pte(cpa, start, end, num_pages - cur_pages, 1410 pmd, pgprot); 1411 } 1412 return num_pages; 1413} 1414 1415static int populate_pud(struct cpa_data *cpa, unsigned long start, p4d_t *p4d, 1416 pgprot_t pgprot) 1417{ 1418 pud_t *pud; 1419 unsigned long end; 1420 long cur_pages = 0; 1421 pgprot_t pud_pgprot; 1422 1423 end = start + (cpa->numpages << PAGE_SHIFT); 1424 1425 /* 1426 * Not on a Gb page boundary? => map everything up to it with 1427 * smaller pages. 1428 */ 1429 if (start & (PUD_SIZE - 1)) { 1430 unsigned long pre_end; 1431 unsigned long next_page = (start + PUD_SIZE) & PUD_MASK; 1432 1433 pre_end = min_t(unsigned long, end, next_page); 1434 cur_pages = (pre_end - start) >> PAGE_SHIFT; 1435 cur_pages = min_t(int, (int)cpa->numpages, cur_pages); 1436 1437 pud = pud_offset(p4d, start); 1438 1439 /* 1440 * Need a PMD page? 1441 */ 1442 if (pud_none(*pud)) 1443 if (alloc_pmd_page(pud)) 1444 return -1; 1445 1446 cur_pages = populate_pmd(cpa, start, pre_end, cur_pages, 1447 pud, pgprot); 1448 if (cur_pages < 0) 1449 return cur_pages; 1450 1451 start = pre_end; 1452 } 1453 1454 /* We mapped them all? */ 1455 if (cpa->numpages == cur_pages) 1456 return cur_pages; 1457 1458 pud = pud_offset(p4d, start); 1459 pud_pgprot = pgprot_4k_2_large(pgprot); 1460 1461 /* 1462 * Map everything starting from the Gb boundary, possibly with 1G pages 1463 */ 1464 while (boot_cpu_has(X86_FEATURE_GBPAGES) && end - start >= PUD_SIZE) { 1465 set_pud(pud, pud_mkhuge(pfn_pud(cpa->pfn, 1466 canon_pgprot(pud_pgprot)))); 1467 1468 start += PUD_SIZE; 1469 cpa->pfn += PUD_SIZE >> PAGE_SHIFT; 1470 cur_pages += PUD_SIZE >> PAGE_SHIFT; 1471 pud++; 1472 } 1473 1474 /* Map trailing leftover */ 1475 if (start < end) { 1476 long tmp; 1477 1478 pud = pud_offset(p4d, start); 1479 if (pud_none(*pud)) 1480 if (alloc_pmd_page(pud)) 1481 return -1; 1482 1483 tmp = populate_pmd(cpa, start, end, cpa->numpages - cur_pages, 1484 pud, pgprot); 1485 if (tmp < 0) 1486 return cur_pages; 1487 1488 cur_pages += tmp; 1489 } 1490 return cur_pages; 1491} 1492 1493/* 1494 * Restrictions for kernel page table do not necessarily apply when mapping in 1495 * an alternate PGD. 1496 */ 1497static int populate_pgd(struct cpa_data *cpa, unsigned long addr) 1498{ 1499 pgprot_t pgprot = __pgprot(_KERNPG_TABLE); 1500 pud_t *pud = NULL; /* shut up gcc */ 1501 p4d_t *p4d; 1502 pgd_t *pgd_entry; 1503 long ret; 1504 1505 pgd_entry = cpa->pgd + pgd_index(addr); 1506 1507 if (pgd_none(*pgd_entry)) { 1508 p4d = (p4d_t *)get_zeroed_page(GFP_KERNEL); 1509 if (!p4d) 1510 return -1; 1511 1512 set_pgd(pgd_entry, __pgd(__pa(p4d) | _KERNPG_TABLE)); 1513 } 1514 1515 /* 1516 * Allocate a PUD page and hand it down for mapping. 1517 */ 1518 p4d = p4d_offset(pgd_entry, addr); 1519 if (p4d_none(*p4d)) { 1520 pud = (pud_t *)get_zeroed_page(GFP_KERNEL); 1521 if (!pud) 1522 return -1; 1523 1524 set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE)); 1525 } 1526 1527 pgprot_val(pgprot) &= ~pgprot_val(cpa->mask_clr); 1528 pgprot_val(pgprot) |= pgprot_val(cpa->mask_set); 1529 1530 ret = populate_pud(cpa, addr, p4d, pgprot); 1531 if (ret < 0) { 1532 /* 1533 * Leave the PUD page in place in case some other CPU or thread 1534 * already found it, but remove any useless entries we just 1535 * added to it. 1536 */ 1537 unmap_pud_range(p4d, addr, 1538 addr + (cpa->numpages << PAGE_SHIFT)); 1539 return ret; 1540 } 1541 1542 cpa->numpages = ret; 1543 return 0; 1544} 1545 1546static int __cpa_process_fault(struct cpa_data *cpa, unsigned long vaddr, 1547 int primary) 1548{ 1549 if (cpa->pgd) { 1550 /* 1551 * Right now, we only execute this code path when mapping 1552 * the EFI virtual memory map regions, no other users 1553 * provide a ->pgd value. This may change in the future. 1554 */ 1555 return populate_pgd(cpa, vaddr); 1556 } 1557 1558 /* 1559 * Ignore all non primary paths. 1560 */ 1561 if (!primary) { 1562 cpa->numpages = 1; 1563 return 0; 1564 } 1565 1566 /* 1567 * Ignore the NULL PTE for kernel identity mapping, as it is expected 1568 * to have holes. 1569 * Also set numpages to '1' indicating that we processed cpa req for 1570 * one virtual address page and its pfn. TBD: numpages can be set based 1571 * on the initial value and the level returned by lookup_address(). 1572 */ 1573 if (within(vaddr, PAGE_OFFSET, 1574 PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT))) { 1575 cpa->numpages = 1; 1576 cpa->pfn = __pa(vaddr) >> PAGE_SHIFT; 1577 return 0; 1578 1579 } else if (__cpa_pfn_in_highmap(cpa->pfn)) { 1580 /* Faults in the highmap are OK, so do not warn: */ 1581 return -EFAULT; 1582 } else { 1583 WARN(1, KERN_WARNING "CPA: called for zero pte. " 1584 "vaddr = %lx cpa->vaddr = %lx\n", vaddr, 1585 *cpa->vaddr); 1586 1587 return -EFAULT; 1588 } 1589} 1590 1591static int __change_page_attr(struct cpa_data *cpa, int primary) 1592{ 1593 unsigned long address; 1594 int do_split, err; 1595 unsigned int level; 1596 pte_t *kpte, old_pte; 1597 1598 address = __cpa_addr(cpa, cpa->curpage); 1599repeat: 1600 kpte = _lookup_address_cpa(cpa, address, &level); 1601 if (!kpte) 1602 return __cpa_process_fault(cpa, address, primary); 1603 1604 old_pte = *kpte; 1605 if (pte_none(old_pte)) 1606 return __cpa_process_fault(cpa, address, primary); 1607 1608 if (level == PG_LEVEL_4K) { 1609 pte_t new_pte; 1610 pgprot_t old_prot = pte_pgprot(old_pte); 1611 pgprot_t new_prot = pte_pgprot(old_pte); 1612 unsigned long pfn = pte_pfn(old_pte); 1613 1614 pgprot_val(new_prot) &= ~pgprot_val(cpa->mask_clr); 1615 pgprot_val(new_prot) |= pgprot_val(cpa->mask_set); 1616 1617 cpa_inc_4k_install(); 1618 /* Hand in lpsize = 0 to enforce the protection mechanism */ 1619 new_prot = static_protections(new_prot, address, pfn, 1, 0, 1620 CPA_PROTECT); 1621 1622 new_prot = verify_rwx(old_prot, new_prot, address, pfn, 1); 1623 1624 new_prot = pgprot_clear_protnone_bits(new_prot); 1625 1626 /* 1627 * We need to keep the pfn from the existing PTE, 1628 * after all we're only going to change its attributes 1629 * not the memory it points to 1630 */ 1631 new_pte = pfn_pte(pfn, new_prot); 1632 cpa->pfn = pfn; 1633 /* 1634 * Do we really change anything ? 1635 */ 1636 if (pte_val(old_pte) != pte_val(new_pte)) { 1637 set_pte_atomic(kpte, new_pte); 1638 cpa->flags |= CPA_FLUSHTLB; 1639 } 1640 cpa->numpages = 1; 1641 return 0; 1642 } 1643 1644 /* 1645 * Check, whether we can keep the large page intact 1646 * and just change the pte: 1647 */ 1648 do_split = should_split_large_page(kpte, address, cpa); 1649 /* 1650 * When the range fits into the existing large page, 1651 * return. cp->numpages and cpa->tlbflush have been updated in 1652 * try_large_page: 1653 */ 1654 if (do_split <= 0) 1655 return do_split; 1656 1657 /* 1658 * We have to split the large page: 1659 */ 1660 err = split_large_page(cpa, kpte, address); 1661 if (!err) 1662 goto repeat; 1663 1664 return err; 1665} 1666 1667static int __change_page_attr_set_clr(struct cpa_data *cpa, int primary); 1668 1669/* 1670 * Check the directmap and "high kernel map" 'aliases'. 1671 */ 1672static int cpa_process_alias(struct cpa_data *cpa) 1673{ 1674 struct cpa_data alias_cpa; 1675 unsigned long laddr = (unsigned long)__va(cpa->pfn << PAGE_SHIFT); 1676 unsigned long vaddr; 1677 int ret; 1678 1679 if (!pfn_range_is_mapped(cpa->pfn, cpa->pfn + 1)) 1680 return 0; 1681 1682 /* 1683 * No need to redo, when the primary call touched the direct 1684 * mapping already: 1685 */ 1686 vaddr = __cpa_addr(cpa, cpa->curpage); 1687 if (!(within(vaddr, PAGE_OFFSET, 1688 PAGE_OFFSET + (max_pfn_mapped << PAGE_SHIFT)))) { 1689 1690 alias_cpa = *cpa; 1691 alias_cpa.vaddr = &laddr; 1692 alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); 1693 alias_cpa.curpage = 0; 1694 1695 /* Directmap always has NX set, do not modify. */ 1696 if (__supported_pte_mask & _PAGE_NX) { 1697 alias_cpa.mask_clr.pgprot &= ~_PAGE_NX; 1698 alias_cpa.mask_set.pgprot &= ~_PAGE_NX; 1699 } 1700 1701 cpa->force_flush_all = 1; 1702 1703 ret = __change_page_attr_set_clr(&alias_cpa, 0); 1704 if (ret) 1705 return ret; 1706 } 1707 1708#ifdef CONFIG_X86_64 1709 /* 1710 * If the primary call didn't touch the high mapping already 1711 * and the physical address is inside the kernel map, we need 1712 * to touch the high mapped kernel as well: 1713 */ 1714 if (!within(vaddr, (unsigned long)_text, _brk_end) && 1715 __cpa_pfn_in_highmap(cpa->pfn)) { 1716 unsigned long temp_cpa_vaddr = (cpa->pfn << PAGE_SHIFT) + 1717 __START_KERNEL_map - phys_base; 1718 alias_cpa = *cpa; 1719 alias_cpa.vaddr = &temp_cpa_vaddr; 1720 alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY); 1721 alias_cpa.curpage = 0; 1722 1723 /* 1724 * [_text, _brk_end) also covers data, do not modify NX except 1725 * in cases where the highmap is the primary target. 1726 */ 1727 if (__supported_pte_mask & _PAGE_NX) { 1728 alias_cpa.mask_clr.pgprot &= ~_PAGE_NX; 1729 alias_cpa.mask_set.pgprot &= ~_PAGE_NX; 1730 } 1731 1732 cpa->force_flush_all = 1; 1733 /* 1734 * The high mapping range is imprecise, so ignore the 1735 * return value. 1736 */ 1737 __change_page_attr_set_clr(&alias_cpa, 0); 1738 } 1739#endif 1740 1741 return 0; 1742} 1743 1744static int __change_page_attr_set_clr(struct cpa_data *cpa, int primary) 1745{ 1746 unsigned long numpages = cpa->numpages; 1747 unsigned long rempages = numpages; 1748 int ret = 0; 1749 1750 /* 1751 * No changes, easy! 1752 */ 1753 if (!(pgprot_val(cpa->mask_set) | pgprot_val(cpa->mask_clr)) && 1754 !cpa->force_split) 1755 return ret; 1756 1757 while (rempages) { 1758 /* 1759 * Store the remaining nr of pages for the large page 1760 * preservation check. 1761 */ 1762 cpa->numpages = rempages; 1763 /* for array changes, we can't use large page */ 1764 if (cpa->flags & (CPA_ARRAY | CPA_PAGES_ARRAY)) 1765 cpa->numpages = 1; 1766 1767 if (!debug_pagealloc_enabled()) 1768 spin_lock(&cpa_lock); 1769 ret = __change_page_attr(cpa, primary); 1770 if (!debug_pagealloc_enabled()) 1771 spin_unlock(&cpa_lock); 1772 if (ret) 1773 goto out; 1774 1775 if (primary && !(cpa->flags & CPA_NO_CHECK_ALIAS)) { 1776 ret = cpa_process_alias(cpa); 1777 if (ret) 1778 goto out; 1779 } 1780 1781 /* 1782 * Adjust the number of pages with the result of the 1783 * CPA operation. Either a large page has been 1784 * preserved or a single page update happened. 1785 */ 1786 BUG_ON(cpa->numpages > rempages || !cpa->numpages); 1787 rempages -= cpa->numpages; 1788 cpa->curpage += cpa->numpages; 1789 } 1790 1791out: 1792 /* Restore the original numpages */ 1793 cpa->numpages = numpages; 1794 return ret; 1795} 1796 1797static int change_page_attr_set_clr(unsigned long *addr, int numpages, 1798 pgprot_t mask_set, pgprot_t mask_clr, 1799 int force_split, int in_flag, 1800 struct page **pages) 1801{ 1802 struct cpa_data cpa; 1803 int ret, cache; 1804 1805 memset(&cpa, 0, sizeof(cpa)); 1806 1807 /* 1808 * Check, if we are requested to set a not supported 1809 * feature. Clearing non-supported features is OK. 1810 */ 1811 mask_set = canon_pgprot(mask_set); 1812 1813 if (!pgprot_val(mask_set) && !pgprot_val(mask_clr) && !force_split) 1814 return 0; 1815 1816 /* Ensure we are PAGE_SIZE aligned */ 1817 if (in_flag & CPA_ARRAY) { 1818 int i; 1819 for (i = 0; i < numpages; i++) { 1820 if (addr[i] & ~PAGE_MASK) { 1821 addr[i] &= PAGE_MASK; 1822 WARN_ON_ONCE(1); 1823 } 1824 } 1825 } else if (!(in_flag & CPA_PAGES_ARRAY)) { 1826 /* 1827 * in_flag of CPA_PAGES_ARRAY implies it is aligned. 1828 * No need to check in that case 1829 */ 1830 if (*addr & ~PAGE_MASK) { 1831 *addr &= PAGE_MASK; 1832 /* 1833 * People should not be passing in unaligned addresses: 1834 */ 1835 WARN_ON_ONCE(1); 1836 } 1837 } 1838 1839 /* Must avoid aliasing mappings in the highmem code */ 1840 kmap_flush_unused(); 1841 1842 vm_unmap_aliases(); 1843 1844 cpa.vaddr = addr; 1845 cpa.pages = pages; 1846 cpa.numpages = numpages; 1847 cpa.mask_set = mask_set; 1848 cpa.mask_clr = mask_clr; 1849 cpa.flags = in_flag; 1850 cpa.curpage = 0; 1851 cpa.force_split = force_split; 1852 1853 ret = __change_page_attr_set_clr(&cpa, 1); 1854 1855 /* 1856 * Check whether we really changed something: 1857 */ 1858 if (!(cpa.flags & CPA_FLUSHTLB)) 1859 goto out; 1860 1861 /* 1862 * No need to flush, when we did not set any of the caching 1863 * attributes: 1864 */ 1865 cache = !!pgprot2cachemode(mask_set); 1866 1867 /* 1868 * On error; flush everything to be sure. 1869 */ 1870 if (ret) { 1871 cpa_flush_all(cache); 1872 goto out; 1873 } 1874 1875 cpa_flush(&cpa, cache); 1876out: 1877 return ret; 1878} 1879 1880static inline int change_page_attr_set(unsigned long *addr, int numpages, 1881 pgprot_t mask, int array) 1882{ 1883 return change_page_attr_set_clr(addr, numpages, mask, __pgprot(0), 0, 1884 (array ? CPA_ARRAY : 0), NULL); 1885} 1886 1887static inline int change_page_attr_clear(unsigned long *addr, int numpages, 1888 pgprot_t mask, int array) 1889{ 1890 return change_page_attr_set_clr(addr, numpages, __pgprot(0), mask, 0, 1891 (array ? CPA_ARRAY : 0), NULL); 1892} 1893 1894static inline int cpa_set_pages_array(struct page **pages, int numpages, 1895 pgprot_t mask) 1896{ 1897 return change_page_attr_set_clr(NULL, numpages, mask, __pgprot(0), 0, 1898 CPA_PAGES_ARRAY, pages); 1899} 1900 1901static inline int cpa_clear_pages_array(struct page **pages, int numpages, 1902 pgprot_t mask) 1903{ 1904 return change_page_attr_set_clr(NULL, numpages, __pgprot(0), mask, 0, 1905 CPA_PAGES_ARRAY, pages); 1906} 1907 1908/* 1909 * __set_memory_prot is an internal helper for callers that have been passed 1910 * a pgprot_t value from upper layers and a reservation has already been taken. 1911 * If you want to set the pgprot to a specific page protocol, use the 1912 * set_memory_xx() functions. 1913 */ 1914int __set_memory_prot(unsigned long addr, int numpages, pgprot_t prot) 1915{ 1916 return change_page_attr_set_clr(&addr, numpages, prot, 1917 __pgprot(~pgprot_val(prot)), 0, 0, 1918 NULL); 1919} 1920 1921int _set_memory_uc(unsigned long addr, int numpages) 1922{ 1923 /* 1924 * for now UC MINUS. see comments in ioremap() 1925 * If you really need strong UC use ioremap_uc(), but note 1926 * that you cannot override IO areas with set_memory_*() as 1927 * these helpers cannot work with IO memory. 1928 */ 1929 return change_page_attr_set(&addr, numpages, 1930 cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS), 1931 0); 1932} 1933 1934int set_memory_uc(unsigned long addr, int numpages) 1935{ 1936 int ret; 1937 1938 /* 1939 * for now UC MINUS. see comments in ioremap() 1940 */ 1941 ret = memtype_reserve(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, 1942 _PAGE_CACHE_MODE_UC_MINUS, NULL); 1943 if (ret) 1944 goto out_err; 1945 1946 ret = _set_memory_uc(addr, numpages); 1947 if (ret) 1948 goto out_free; 1949 1950 return 0; 1951 1952out_free: 1953 memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); 1954out_err: 1955 return ret; 1956} 1957EXPORT_SYMBOL(set_memory_uc); 1958 1959int _set_memory_wc(unsigned long addr, int numpages) 1960{ 1961 int ret; 1962 1963 ret = change_page_attr_set(&addr, numpages, 1964 cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS), 1965 0); 1966 if (!ret) { 1967 ret = change_page_attr_set_clr(&addr, numpages, 1968 cachemode2pgprot(_PAGE_CACHE_MODE_WC), 1969 __pgprot(_PAGE_CACHE_MASK), 1970 0, 0, NULL); 1971 } 1972 return ret; 1973} 1974 1975int set_memory_wc(unsigned long addr, int numpages) 1976{ 1977 int ret; 1978 1979 ret = memtype_reserve(__pa(addr), __pa(addr) + numpages * PAGE_SIZE, 1980 _PAGE_CACHE_MODE_WC, NULL); 1981 if (ret) 1982 return ret; 1983 1984 ret = _set_memory_wc(addr, numpages); 1985 if (ret) 1986 memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); 1987 1988 return ret; 1989} 1990EXPORT_SYMBOL(set_memory_wc); 1991 1992int _set_memory_wt(unsigned long addr, int numpages) 1993{ 1994 return change_page_attr_set(&addr, numpages, 1995 cachemode2pgprot(_PAGE_CACHE_MODE_WT), 0); 1996} 1997 1998int _set_memory_wb(unsigned long addr, int numpages) 1999{ 2000 /* WB cache mode is hard wired to all cache attribute bits being 0 */ 2001 return change_page_attr_clear(&addr, numpages, 2002 __pgprot(_PAGE_CACHE_MASK), 0); 2003} 2004 2005int set_memory_wb(unsigned long addr, int numpages) 2006{ 2007 int ret; 2008 2009 ret = _set_memory_wb(addr, numpages); 2010 if (ret) 2011 return ret; 2012 2013 memtype_free(__pa(addr), __pa(addr) + numpages * PAGE_SIZE); 2014 return 0; 2015} 2016EXPORT_SYMBOL(set_memory_wb); 2017 2018/* Prevent speculative access to a page by marking it not-present */ 2019#ifdef CONFIG_X86_64 2020int set_mce_nospec(unsigned long pfn) 2021{ 2022 unsigned long decoy_addr; 2023 int rc; 2024 2025 /* SGX pages are not in the 1:1 map */ 2026 if (arch_is_platform_page(pfn << PAGE_SHIFT)) 2027 return 0; 2028 /* 2029 * We would like to just call: 2030 * set_memory_XX((unsigned long)pfn_to_kaddr(pfn), 1); 2031 * but doing that would radically increase the odds of a 2032 * speculative access to the poison page because we'd have 2033 * the virtual address of the kernel 1:1 mapping sitting 2034 * around in registers. 2035 * Instead we get tricky. We create a non-canonical address 2036 * that looks just like the one we want, but has bit 63 flipped. 2037 * This relies on set_memory_XX() properly sanitizing any __pa() 2038 * results with __PHYSICAL_MASK or PTE_PFN_MASK. 2039 */ 2040 decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63)); 2041 2042 rc = set_memory_np(decoy_addr, 1); 2043 if (rc) 2044 pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn); 2045 return rc; 2046} 2047 2048/* Restore full speculative operation to the pfn. */ 2049int clear_mce_nospec(unsigned long pfn) 2050{ 2051 unsigned long addr = (unsigned long) pfn_to_kaddr(pfn); 2052 2053 return set_memory_p(addr, 1); 2054} 2055EXPORT_SYMBOL_GPL(clear_mce_nospec); 2056#endif /* CONFIG_X86_64 */ 2057 2058int set_memory_x(unsigned long addr, int numpages) 2059{ 2060 if (!(__supported_pte_mask & _PAGE_NX)) 2061 return 0; 2062 2063 return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_NX), 0); 2064} 2065 2066int set_memory_nx(unsigned long addr, int numpages) 2067{ 2068 if (!(__supported_pte_mask & _PAGE_NX)) 2069 return 0; 2070 2071 return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_NX), 0); 2072} 2073 2074int set_memory_ro(unsigned long addr, int numpages) 2075{ 2076 return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW | _PAGE_DIRTY), 0); 2077} 2078 2079int set_memory_rox(unsigned long addr, int numpages) 2080{ 2081 pgprot_t clr = __pgprot(_PAGE_RW | _PAGE_DIRTY); 2082 2083 if (__supported_pte_mask & _PAGE_NX) 2084 clr.pgprot |= _PAGE_NX; 2085 2086 return change_page_attr_clear(&addr, numpages, clr, 0); 2087} 2088 2089int set_memory_rw(unsigned long addr, int numpages) 2090{ 2091 return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0); 2092} 2093 2094int set_memory_np(unsigned long addr, int numpages) 2095{ 2096 return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_PRESENT), 0); 2097} 2098 2099int set_memory_np_noalias(unsigned long addr, int numpages) 2100{ 2101 return change_page_attr_set_clr(&addr, numpages, __pgprot(0), 2102 __pgprot(_PAGE_PRESENT), 0, 2103 CPA_NO_CHECK_ALIAS, NULL); 2104} 2105 2106int set_memory_p(unsigned long addr, int numpages) 2107{ 2108 return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_PRESENT), 0); 2109} 2110 2111int set_memory_4k(unsigned long addr, int numpages) 2112{ 2113 return change_page_attr_set_clr(&addr, numpages, __pgprot(0), 2114 __pgprot(0), 1, 0, NULL); 2115} 2116 2117int set_memory_nonglobal(unsigned long addr, int numpages) 2118{ 2119 return change_page_attr_clear(&addr, numpages, 2120 __pgprot(_PAGE_GLOBAL), 0); 2121} 2122 2123int set_memory_global(unsigned long addr, int numpages) 2124{ 2125 return change_page_attr_set(&addr, numpages, 2126 __pgprot(_PAGE_GLOBAL), 0); 2127} 2128 2129/* 2130 * __set_memory_enc_pgtable() is used for the hypervisors that get 2131 * informed about "encryption" status via page tables. 2132 */ 2133static int __set_memory_enc_pgtable(unsigned long addr, int numpages, bool enc) 2134{ 2135 pgprot_t empty = __pgprot(0); 2136 struct cpa_data cpa; 2137 int ret; 2138 2139 /* Should not be working on unaligned addresses */ 2140 if (WARN_ONCE(addr & ~PAGE_MASK, "misaligned address: %#lx\n", addr)) 2141 addr &= PAGE_MASK; 2142 2143 memset(&cpa, 0, sizeof(cpa)); 2144 cpa.vaddr = &addr; 2145 cpa.numpages = numpages; 2146 cpa.mask_set = enc ? pgprot_encrypted(empty) : pgprot_decrypted(empty); 2147 cpa.mask_clr = enc ? pgprot_decrypted(empty) : pgprot_encrypted(empty); 2148 cpa.pgd = init_mm.pgd; 2149 2150 /* Must avoid aliasing mappings in the highmem code */ 2151 kmap_flush_unused(); 2152 vm_unmap_aliases(); 2153 2154 /* Flush the caches as needed before changing the encryption attribute. */ 2155 if (x86_platform.guest.enc_tlb_flush_required(enc)) 2156 cpa_flush(&cpa, x86_platform.guest.enc_cache_flush_required()); 2157 2158 /* Notify hypervisor that we are about to set/clr encryption attribute. */ 2159 if (!x86_platform.guest.enc_status_change_prepare(addr, numpages, enc)) 2160 goto vmm_fail; 2161 2162 ret = __change_page_attr_set_clr(&cpa, 1); 2163 2164 /* 2165 * After changing the encryption attribute, we need to flush TLBs again 2166 * in case any speculative TLB caching occurred (but no need to flush 2167 * caches again). We could just use cpa_flush_all(), but in case TLB 2168 * flushing gets optimized in the cpa_flush() path use the same logic 2169 * as above. 2170 */ 2171 cpa_flush(&cpa, 0); 2172 2173 if (ret) 2174 return ret; 2175 2176 /* Notify hypervisor that we have successfully set/clr encryption attribute. */ 2177 if (!x86_platform.guest.enc_status_change_finish(addr, numpages, enc)) 2178 goto vmm_fail; 2179 2180 return 0; 2181 2182vmm_fail: 2183 WARN_ONCE(1, "CPA VMM failure to convert memory (addr=%p, numpages=%d) to %s.\n", 2184 (void *)addr, numpages, enc ? "private" : "shared"); 2185 2186 return -EIO; 2187} 2188 2189static int __set_memory_enc_dec(unsigned long addr, int numpages, bool enc) 2190{ 2191 if (cc_platform_has(CC_ATTR_MEM_ENCRYPT)) 2192 return __set_memory_enc_pgtable(addr, numpages, enc); 2193 2194 return 0; 2195} 2196 2197int set_memory_encrypted(unsigned long addr, int numpages) 2198{ 2199 return __set_memory_enc_dec(addr, numpages, true); 2200} 2201EXPORT_SYMBOL_GPL(set_memory_encrypted); 2202 2203int set_memory_decrypted(unsigned long addr, int numpages) 2204{ 2205 return __set_memory_enc_dec(addr, numpages, false); 2206} 2207EXPORT_SYMBOL_GPL(set_memory_decrypted); 2208 2209int set_pages_uc(struct page *page, int numpages) 2210{ 2211 unsigned long addr = (unsigned long)page_address(page); 2212 2213 return set_memory_uc(addr, numpages); 2214} 2215EXPORT_SYMBOL(set_pages_uc); 2216 2217static int _set_pages_array(struct page **pages, int numpages, 2218 enum page_cache_mode new_type) 2219{ 2220 unsigned long start; 2221 unsigned long end; 2222 enum page_cache_mode set_type; 2223 int i; 2224 int free_idx; 2225 int ret; 2226 2227 for (i = 0; i < numpages; i++) { 2228 if (PageHighMem(pages[i])) 2229 continue; 2230 start = page_to_pfn(pages[i]) << PAGE_SHIFT; 2231 end = start + PAGE_SIZE; 2232 if (memtype_reserve(start, end, new_type, NULL)) 2233 goto err_out; 2234 } 2235 2236 /* If WC, set to UC- first and then WC */ 2237 set_type = (new_type == _PAGE_CACHE_MODE_WC) ? 2238 _PAGE_CACHE_MODE_UC_MINUS : new_type; 2239 2240 ret = cpa_set_pages_array(pages, numpages, 2241 cachemode2pgprot(set_type)); 2242 if (!ret && new_type == _PAGE_CACHE_MODE_WC) 2243 ret = change_page_attr_set_clr(NULL, numpages, 2244 cachemode2pgprot( 2245 _PAGE_CACHE_MODE_WC), 2246 __pgprot(_PAGE_CACHE_MASK), 2247 0, CPA_PAGES_ARRAY, pages); 2248 if (ret) 2249 goto err_out; 2250 return 0; /* Success */ 2251err_out: 2252 free_idx = i; 2253 for (i = 0; i < free_idx; i++) { 2254 if (PageHighMem(pages[i])) 2255 continue; 2256 start = page_to_pfn(pages[i]) << PAGE_SHIFT; 2257 end = start + PAGE_SIZE; 2258 memtype_free(start, end); 2259 } 2260 return -EINVAL; 2261} 2262 2263int set_pages_array_uc(struct page **pages, int numpages) 2264{ 2265 return _set_pages_array(pages, numpages, _PAGE_CACHE_MODE_UC_MINUS); 2266} 2267EXPORT_SYMBOL(set_pages_array_uc); 2268 2269int set_pages_array_wc(struct page **pages, int numpages) 2270{ 2271 return _set_pages_array(pages, numpages, _PAGE_CACHE_MODE_WC); 2272} 2273EXPORT_SYMBOL(set_pages_array_wc); 2274 2275int set_pages_wb(struct page *page, int numpages) 2276{ 2277 unsigned long addr = (unsigned long)page_address(page); 2278 2279 return set_memory_wb(addr, numpages); 2280} 2281EXPORT_SYMBOL(set_pages_wb); 2282 2283int set_pages_array_wb(struct page **pages, int numpages) 2284{ 2285 int retval; 2286 unsigned long start; 2287 unsigned long end; 2288 int i; 2289 2290 /* WB cache mode is hard wired to all cache attribute bits being 0 */ 2291 retval = cpa_clear_pages_array(pages, numpages, 2292 __pgprot(_PAGE_CACHE_MASK)); 2293 if (retval) 2294 return retval; 2295 2296 for (i = 0; i < numpages; i++) { 2297 if (PageHighMem(pages[i])) 2298 continue; 2299 start = page_to_pfn(pages[i]) << PAGE_SHIFT; 2300 end = start + PAGE_SIZE; 2301 memtype_free(start, end); 2302 } 2303 2304 return 0; 2305} 2306EXPORT_SYMBOL(set_pages_array_wb); 2307 2308int set_pages_ro(struct page *page, int numpages) 2309{ 2310 unsigned long addr = (unsigned long)page_address(page); 2311 2312 return set_memory_ro(addr, numpages); 2313} 2314 2315int set_pages_rw(struct page *page, int numpages) 2316{ 2317 unsigned long addr = (unsigned long)page_address(page); 2318 2319 return set_memory_rw(addr, numpages); 2320} 2321 2322static int __set_pages_p(struct page *page, int numpages) 2323{ 2324 unsigned long tempaddr = (unsigned long) page_address(page); 2325 struct cpa_data cpa = { .vaddr = &tempaddr, 2326 .pgd = NULL, 2327 .numpages = numpages, 2328 .mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW), 2329 .mask_clr = __pgprot(0), 2330 .flags = CPA_NO_CHECK_ALIAS }; 2331 2332 /* 2333 * No alias checking needed for setting present flag. otherwise, 2334 * we may need to break large pages for 64-bit kernel text 2335 * mappings (this adds to complexity if we want to do this from 2336 * atomic context especially). Let's keep it simple! 2337 */ 2338 return __change_page_attr_set_clr(&cpa, 1); 2339} 2340 2341static int __set_pages_np(struct page *page, int numpages) 2342{ 2343 unsigned long tempaddr = (unsigned long) page_address(page); 2344 struct cpa_data cpa = { .vaddr = &tempaddr, 2345 .pgd = NULL, 2346 .numpages = numpages, 2347 .mask_set = __pgprot(0), 2348 .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), 2349 .flags = CPA_NO_CHECK_ALIAS }; 2350 2351 /* 2352 * No alias checking needed for setting not present flag. otherwise, 2353 * we may need to break large pages for 64-bit kernel text 2354 * mappings (this adds to complexity if we want to do this from 2355 * atomic context especially). Let's keep it simple! 2356 */ 2357 return __change_page_attr_set_clr(&cpa, 1); 2358} 2359 2360int set_direct_map_invalid_noflush(struct page *page) 2361{ 2362 return __set_pages_np(page, 1); 2363} 2364 2365int set_direct_map_default_noflush(struct page *page) 2366{ 2367 return __set_pages_p(page, 1); 2368} 2369 2370#ifdef CONFIG_DEBUG_PAGEALLOC 2371void __kernel_map_pages(struct page *page, int numpages, int enable) 2372{ 2373 if (PageHighMem(page)) 2374 return; 2375 if (!enable) { 2376 debug_check_no_locks_freed(page_address(page), 2377 numpages * PAGE_SIZE); 2378 } 2379 2380 /* 2381 * The return value is ignored as the calls cannot fail. 2382 * Large pages for identity mappings are not used at boot time 2383 * and hence no memory allocations during large page split. 2384 */ 2385 if (enable) 2386 __set_pages_p(page, numpages); 2387 else 2388 __set_pages_np(page, numpages); 2389 2390 /* 2391 * We should perform an IPI and flush all tlbs, 2392 * but that can deadlock->flush only current cpu. 2393 * Preemption needs to be disabled around __flush_tlb_all() due to 2394 * CR3 reload in __native_flush_tlb(). 2395 */ 2396 preempt_disable(); 2397 __flush_tlb_all(); 2398 preempt_enable(); 2399 2400 arch_flush_lazy_mmu_mode(); 2401} 2402#endif /* CONFIG_DEBUG_PAGEALLOC */ 2403 2404bool kernel_page_present(struct page *page) 2405{ 2406 unsigned int level; 2407 pte_t *pte; 2408 2409 if (PageHighMem(page)) 2410 return false; 2411 2412 pte = lookup_address((unsigned long)page_address(page), &level); 2413 return (pte_val(*pte) & _PAGE_PRESENT); 2414} 2415 2416int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address, 2417 unsigned numpages, unsigned long page_flags) 2418{ 2419 int retval = -EINVAL; 2420 2421 struct cpa_data cpa = { 2422 .vaddr = &address, 2423 .pfn = pfn, 2424 .pgd = pgd, 2425 .numpages = numpages, 2426 .mask_set = __pgprot(0), 2427 .mask_clr = __pgprot(~page_flags & (_PAGE_NX|_PAGE_RW)), 2428 .flags = CPA_NO_CHECK_ALIAS, 2429 }; 2430 2431 WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); 2432 2433 if (!(__supported_pte_mask & _PAGE_NX)) 2434 goto out; 2435 2436 if (!(page_flags & _PAGE_ENC)) 2437 cpa.mask_clr = pgprot_encrypted(cpa.mask_clr); 2438 2439 cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags); 2440 2441 retval = __change_page_attr_set_clr(&cpa, 1); 2442 __flush_tlb_all(); 2443 2444out: 2445 return retval; 2446} 2447 2448/* 2449 * __flush_tlb_all() flushes mappings only on current CPU and hence this 2450 * function shouldn't be used in an SMP environment. Presently, it's used only 2451 * during boot (way before smp_init()) by EFI subsystem and hence is ok. 2452 */ 2453int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address, 2454 unsigned long numpages) 2455{ 2456 int retval; 2457 2458 /* 2459 * The typical sequence for unmapping is to find a pte through 2460 * lookup_address_in_pgd() (ideally, it should never return NULL because 2461 * the address is already mapped) and change its protections. As pfn is 2462 * the *target* of a mapping, it's not useful while unmapping. 2463 */ 2464 struct cpa_data cpa = { 2465 .vaddr = &address, 2466 .pfn = 0, 2467 .pgd = pgd, 2468 .numpages = numpages, 2469 .mask_set = __pgprot(0), 2470 .mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW), 2471 .flags = CPA_NO_CHECK_ALIAS, 2472 }; 2473 2474 WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP"); 2475 2476 retval = __change_page_attr_set_clr(&cpa, 1); 2477 __flush_tlb_all(); 2478 2479 return retval; 2480} 2481 2482/* 2483 * The testcases use internal knowledge of the implementation that shouldn't 2484 * be exposed to the rest of the kernel. Include these directly here. 2485 */ 2486#ifdef CONFIG_CPA_DEBUG 2487#include "cpa-test.c" 2488#endif 2489