2 * Copyright 2002 Andi Kleen, SuSE Labs.
3 * Thanks to Ben LaHaise for precious feedback.
5 #include <linux/highmem.h>
6 #include <linux/memblock.h>
7 #include <linux/sched.h>
9 #include <linux/interrupt.h>
10 #include <linux/seq_file.h>
11 #include <linux/debugfs.h>
12 #include <linux/pfn.h>
13 #include <linux/percpu.h>
14 #include <linux/gfp.h>
15 #include <linux/pci.h>
16 #include <linux/vmalloc.h>
18 #include <asm/e820/api.h>
19 #include <asm/processor.h>
20 #include <asm/tlbflush.h>
21 #include <asm/sections.h>
22 #include <asm/setup.h>
23 #include <linux/uaccess.h>
24 #include <asm/pgalloc.h>
25 #include <asm/proto.h>
27 #include <asm/set_memory.h>
29 #include "mm_internal.h"
32 * The current flushing context - we pass it instead of 5 arguments:
39 unsigned long numpages
;
40 unsigned long curpage
;
43 unsigned int force_split
: 1,
44 force_static_prot
: 1;
54 static const int cpa_warn_level
= CPA_PROTECT
;
57 * Serialize cpa() (for !DEBUG_PAGEALLOC which uses large identity mappings)
58 * using cpa_lock. So that we don't allow any other cpu, with stale large tlb
59 * entries change the page attribute in parallel to some other cpu
60 * splitting a large page entry along with changing the attribute.
62 static DEFINE_SPINLOCK(cpa_lock
);
64 #define CPA_FLUSHTLB 1
66 #define CPA_PAGES_ARRAY 4
67 #define CPA_NO_CHECK_ALIAS 8 /* Do not search for aliases */
70 static unsigned long direct_pages_count
[PG_LEVEL_NUM
];
72 void update_page_count(int level
, unsigned long pages
)
74 /* Protect against CPA */
76 direct_pages_count
[level
] += pages
;
77 spin_unlock(&pgd_lock
);
80 static void split_page_count(int level
)
82 if (direct_pages_count
[level
] == 0)
85 direct_pages_count
[level
]--;
86 direct_pages_count
[level
- 1] += PTRS_PER_PTE
;
89 void arch_report_meminfo(struct seq_file
*m
)
91 seq_printf(m
, "DirectMap4k: %8lu kB\n",
92 direct_pages_count
[PG_LEVEL_4K
] << 2);
93 #if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
94 seq_printf(m
, "DirectMap2M: %8lu kB\n",
95 direct_pages_count
[PG_LEVEL_2M
] << 11);
97 seq_printf(m
, "DirectMap4M: %8lu kB\n",
98 direct_pages_count
[PG_LEVEL_2M
] << 12);
101 seq_printf(m
, "DirectMap1G: %8lu kB\n",
102 direct_pages_count
[PG_LEVEL_1G
] << 20);
105 static inline void split_page_count(int level
) { }
108 #ifdef CONFIG_X86_CPA_STATISTICS
110 static unsigned long cpa_1g_checked
;
111 static unsigned long cpa_1g_sameprot
;
112 static unsigned long cpa_1g_preserved
;
113 static unsigned long cpa_2m_checked
;
114 static unsigned long cpa_2m_sameprot
;
115 static unsigned long cpa_2m_preserved
;
116 static unsigned long cpa_4k_install
;
118 static inline void cpa_inc_1g_checked(void)
123 static inline void cpa_inc_2m_checked(void)
128 static inline void cpa_inc_4k_install(void)
133 static inline void cpa_inc_lp_sameprot(int level
)
135 if (level
== PG_LEVEL_1G
)
141 static inline void cpa_inc_lp_preserved(int level
)
143 if (level
== PG_LEVEL_1G
)
149 static int cpastats_show(struct seq_file
*m
, void *p
)
151 seq_printf(m
, "1G pages checked: %16lu\n", cpa_1g_checked
);
152 seq_printf(m
, "1G pages sameprot: %16lu\n", cpa_1g_sameprot
);
153 seq_printf(m
, "1G pages preserved: %16lu\n", cpa_1g_preserved
);
154 seq_printf(m
, "2M pages checked: %16lu\n", cpa_2m_checked
);
155 seq_printf(m
, "2M pages sameprot: %16lu\n", cpa_2m_sameprot
);
156 seq_printf(m
, "2M pages preserved: %16lu\n", cpa_2m_preserved
);
157 seq_printf(m
, "4K pages set-checked: %16lu\n", cpa_4k_install
);
161 static int cpastats_open(struct inode
*inode
, struct file
*file
)
163 return single_open(file
, cpastats_show
, NULL
);
166 static const struct file_operations cpastats_fops
= {
167 .open
= cpastats_open
,
170 .release
= single_release
,
173 static int __init
cpa_stats_init(void)
175 debugfs_create_file("cpa_stats", S_IRUSR
, arch_debugfs_dir
, NULL
,
179 late_initcall(cpa_stats_init
);
181 static inline void cpa_inc_1g_checked(void) { }
182 static inline void cpa_inc_2m_checked(void) { }
183 static inline void cpa_inc_4k_install(void) { }
184 static inline void cpa_inc_lp_sameprot(int level
) { }
185 static inline void cpa_inc_lp_preserved(int level
) { }
190 within(unsigned long addr
, unsigned long start
, unsigned long end
)
192 return addr
>= start
&& addr
< end
;
196 within_inclusive(unsigned long addr
, unsigned long start
, unsigned long end
)
198 return addr
>= start
&& addr
<= end
;
203 static inline unsigned long highmap_start_pfn(void)
205 return __pa_symbol(_text
) >> PAGE_SHIFT
;
208 static inline unsigned long highmap_end_pfn(void)
210 /* Do not reference physical address outside the kernel. */
211 return __pa_symbol(roundup(_brk_end
, PMD_SIZE
) - 1) >> PAGE_SHIFT
;
214 static bool __cpa_pfn_in_highmap(unsigned long pfn
)
217 * Kernel text has an alias mapping at a high address, known
220 return within_inclusive(pfn
, highmap_start_pfn(), highmap_end_pfn());
225 static bool __cpa_pfn_in_highmap(unsigned long pfn
)
227 /* There is no highmap on 32-bit */
234 * See set_mce_nospec().
236 * Machine check recovery code needs to change cache mode of poisoned pages to
237 * UC to avoid speculative access logging another error. But passing the
238 * address of the 1:1 mapping to set_memory_uc() is a fine way to encourage a
239 * speculative access. So we cheat and flip the top bit of the address. This
240 * works fine for the code that updates the page tables. But at the end of the
241 * process we need to flush the TLB and cache and the non-canonical address
242 * causes a #GP fault when used by the INVLPG and CLFLUSH instructions.
244 * But in the common case we already have a canonical address. This code
245 * will fix the top bit if needed and is a no-op otherwise.
247 static inline unsigned long fix_addr(unsigned long addr
)
250 return (long)(addr
<< 1) >> 1;
256 static unsigned long __cpa_addr(struct cpa_data
*cpa
, unsigned long idx
)
258 if (cpa
->flags
& CPA_PAGES_ARRAY
) {
259 struct page
*page
= cpa
->pages
[idx
];
261 if (unlikely(PageHighMem(page
)))
264 return (unsigned long)page_address(page
);
267 if (cpa
->flags
& CPA_ARRAY
)
268 return cpa
->vaddr
[idx
];
270 return *cpa
->vaddr
+ idx
* PAGE_SIZE
;
277 static void clflush_cache_range_opt(void *vaddr
, unsigned int size
)
279 const unsigned long clflush_size
= boot_cpu_data
.x86_clflush_size
;
280 void *p
= (void *)((unsigned long)vaddr
& ~(clflush_size
- 1));
281 void *vend
= vaddr
+ size
;
286 for (; p
< vend
; p
+= clflush_size
)
291 * clflush_cache_range - flush a cache range with clflush
292 * @vaddr: virtual start address
293 * @size: number of bytes to flush
295 * CLFLUSHOPT is an unordered instruction which needs fencing with MFENCE or
296 * SFENCE to avoid ordering issues.
298 void clflush_cache_range(void *vaddr
, unsigned int size
)
301 clflush_cache_range_opt(vaddr
, size
);
304 EXPORT_SYMBOL_GPL(clflush_cache_range
);
306 void arch_invalidate_pmem(void *addr
, size_t size
)
308 clflush_cache_range(addr
, size
);
310 EXPORT_SYMBOL_GPL(arch_invalidate_pmem
);
312 static void __cpa_flush_all(void *arg
)
314 unsigned long cache
= (unsigned long)arg
;
317 * Flush all to work around Errata in early athlons regarding
318 * large page flushing.
322 if (cache
&& boot_cpu_data
.x86
>= 4)
326 static void cpa_flush_all(unsigned long cache
)
328 BUG_ON(irqs_disabled() && !early_boot_irqs_disabled
);
330 on_each_cpu(__cpa_flush_all
, (void *) cache
, 1);
333 void __cpa_flush_tlb(void *data
)
335 struct cpa_data
*cpa
= data
;
338 for (i
= 0; i
< cpa
->numpages
; i
++)
339 __flush_tlb_one_kernel(fix_addr(__cpa_addr(cpa
, i
)));
342 static void cpa_flush(struct cpa_data
*data
, int cache
)
344 struct cpa_data
*cpa
= data
;
347 BUG_ON(irqs_disabled() && !early_boot_irqs_disabled
);
349 if (cache
&& !static_cpu_has(X86_FEATURE_CLFLUSH
)) {
350 cpa_flush_all(cache
);
354 if (cpa
->numpages
<= tlb_single_page_flush_ceiling
)
355 on_each_cpu(__cpa_flush_tlb
, cpa
, 1);
363 for (i
= 0; i
< cpa
->numpages
; i
++) {
364 unsigned long addr
= __cpa_addr(cpa
, i
);
367 pte_t
*pte
= lookup_address(addr
, &level
);
370 * Only flush present addresses:
372 if (pte
&& (pte_val(*pte
) & _PAGE_PRESENT
))
373 clflush_cache_range_opt((void *)fix_addr(addr
), PAGE_SIZE
);
378 static bool overlaps(unsigned long r1_start
, unsigned long r1_end
,
379 unsigned long r2_start
, unsigned long r2_end
)
381 return (r1_start
<= r2_end
&& r1_end
>= r2_start
) ||
382 (r2_start
<= r1_end
&& r2_end
>= r1_start
);
385 #ifdef CONFIG_PCI_BIOS
387 * The BIOS area between 640k and 1Mb needs to be executable for PCI BIOS
388 * based config access (CONFIG_PCI_GOBIOS) support.
390 #define BIOS_PFN PFN_DOWN(BIOS_BEGIN)
391 #define BIOS_PFN_END PFN_DOWN(BIOS_END - 1)
393 static pgprotval_t
protect_pci_bios(unsigned long spfn
, unsigned long epfn
)
395 if (pcibios_enabled
&& overlaps(spfn
, epfn
, BIOS_PFN
, BIOS_PFN_END
))
400 static pgprotval_t
protect_pci_bios(unsigned long spfn
, unsigned long epfn
)
407 * The .rodata section needs to be read-only. Using the pfn catches all
408 * aliases. This also includes __ro_after_init, so do not enforce until
409 * kernel_set_to_readonly is true.
411 static pgprotval_t
protect_rodata(unsigned long spfn
, unsigned long epfn
)
413 unsigned long epfn_ro
, spfn_ro
= PFN_DOWN(__pa_symbol(__start_rodata
));
416 * Note: __end_rodata is at page aligned and not inclusive, so
417 * subtract 1 to get the last enforced PFN in the rodata area.
419 epfn_ro
= PFN_DOWN(__pa_symbol(__end_rodata
)) - 1;
421 if (kernel_set_to_readonly
&& overlaps(spfn
, epfn
, spfn_ro
, epfn_ro
))
427 * Protect kernel text against becoming non executable by forbidding
428 * _PAGE_NX. This protects only the high kernel mapping (_text -> _etext)
429 * out of which the kernel actually executes. Do not protect the low
432 * This does not cover __inittext since that is gone after boot.
434 static pgprotval_t
protect_kernel_text(unsigned long start
, unsigned long end
)
436 unsigned long t_end
= (unsigned long)_etext
- 1;
437 unsigned long t_start
= (unsigned long)_text
;
439 if (overlaps(start
, end
, t_start
, t_end
))
444 #if defined(CONFIG_X86_64)
446 * Once the kernel maps the text as RO (kernel_set_to_readonly is set),
447 * kernel text mappings for the large page aligned text, rodata sections
448 * will be always read-only. For the kernel identity mappings covering the
449 * holes caused by this alignment can be anything that user asks.
451 * This will preserve the large page mappings for kernel text/data at no
454 static pgprotval_t
protect_kernel_text_ro(unsigned long start
,
457 unsigned long t_end
= (unsigned long)__end_rodata_hpage_align
- 1;
458 unsigned long t_start
= (unsigned long)_text
;
461 if (!kernel_set_to_readonly
|| !overlaps(start
, end
, t_start
, t_end
))
464 * Don't enforce the !RW mapping for the kernel text mapping, if
465 * the current mapping is already using small page mapping. No
466 * need to work hard to preserve large page mappings in this case.
468 * This also fixes the Linux Xen paravirt guest boot failure caused
469 * by unexpected read-only mappings for kernel identity
470 * mappings. In this paravirt guest case, the kernel text mapping
471 * and the kernel identity mapping share the same page-table pages,
472 * so the protections for kernel text and identity mappings have to
475 if (lookup_address(start
, &level
) && (level
!= PG_LEVEL_4K
))
480 static pgprotval_t
protect_kernel_text_ro(unsigned long start
,
487 static inline bool conflicts(pgprot_t prot
, pgprotval_t val
)
489 return (pgprot_val(prot
) & ~val
) != pgprot_val(prot
);
492 static inline void check_conflict(int warnlvl
, pgprot_t prot
, pgprotval_t val
,
493 unsigned long start
, unsigned long end
,
494 unsigned long pfn
, const char *txt
)
496 static const char *lvltxt
[] = {
497 [CPA_CONFLICT
] = "conflict",
498 [CPA_PROTECT
] = "protect",
499 [CPA_DETECT
] = "detect",
502 if (warnlvl
> cpa_warn_level
|| !conflicts(prot
, val
))
505 pr_warn("CPA %8s %10s: 0x%016lx - 0x%016lx PFN %lx req %016llx prevent %016llx\n",
506 lvltxt
[warnlvl
], txt
, start
, end
, pfn
, (unsigned long long)pgprot_val(prot
),
507 (unsigned long long)val
);
511 * Certain areas of memory on x86 require very specific protection flags,
512 * for example the BIOS area or kernel text. Callers don't always get this
513 * right (again, ioremap() on BIOS memory is not uncommon) so this function
514 * checks and fixes these known static required protection bits.
516 static inline pgprot_t
static_protections(pgprot_t prot
, unsigned long start
,
517 unsigned long pfn
, unsigned long npg
,
520 pgprotval_t forbidden
, res
;
524 * There is no point in checking RW/NX conflicts when the requested
525 * mapping is setting the page !PRESENT.
527 if (!(pgprot_val(prot
) & _PAGE_PRESENT
))
530 /* Operate on the virtual address */
531 end
= start
+ npg
* PAGE_SIZE
- 1;
533 res
= protect_kernel_text(start
, end
);
534 check_conflict(warnlvl
, prot
, res
, start
, end
, pfn
, "Text NX");
537 res
= protect_kernel_text_ro(start
, end
);
538 check_conflict(warnlvl
, prot
, res
, start
, end
, pfn
, "Text RO");
541 /* Check the PFN directly */
542 res
= protect_pci_bios(pfn
, pfn
+ npg
- 1);
543 check_conflict(warnlvl
, prot
, res
, start
, end
, pfn
, "PCIBIOS NX");
546 res
= protect_rodata(pfn
, pfn
+ npg
- 1);
547 check_conflict(warnlvl
, prot
, res
, start
, end
, pfn
, "Rodata RO");
550 return __pgprot(pgprot_val(prot
) & ~forbidden
);
554 * Lookup the page table entry for a virtual address in a specific pgd.
555 * Return a pointer to the entry and the level of the mapping.
557 pte_t
*lookup_address_in_pgd(pgd_t
*pgd
, unsigned long address
,
564 *level
= PG_LEVEL_NONE
;
569 p4d
= p4d_offset(pgd
, address
);
573 *level
= PG_LEVEL_512G
;
574 if (p4d_large(*p4d
) || !p4d_present(*p4d
))
577 pud
= pud_offset(p4d
, address
);
581 *level
= PG_LEVEL_1G
;
582 if (pud_large(*pud
) || !pud_present(*pud
))
585 pmd
= pmd_offset(pud
, address
);
589 *level
= PG_LEVEL_2M
;
590 if (pmd_large(*pmd
) || !pmd_present(*pmd
))
593 *level
= PG_LEVEL_4K
;
595 return pte_offset_kernel(pmd
, address
);
599 * Lookup the page table entry for a virtual address. Return a pointer
600 * to the entry and the level of the mapping.
602 * Note: We return pud and pmd either when the entry is marked large
603 * or when the present bit is not set. Otherwise we would return a
604 * pointer to a nonexisting mapping.
606 pte_t
*lookup_address(unsigned long address
, unsigned int *level
)
608 return lookup_address_in_pgd(pgd_offset_k(address
), address
, level
);
610 EXPORT_SYMBOL_GPL(lookup_address
);
612 static pte_t
*_lookup_address_cpa(struct cpa_data
*cpa
, unsigned long address
,
616 return lookup_address_in_pgd(cpa
->pgd
+ pgd_index(address
),
619 return lookup_address(address
, level
);
623 * Lookup the PMD entry for a virtual address. Return a pointer to the entry
624 * or NULL if not present.
626 pmd_t
*lookup_pmd_address(unsigned long address
)
632 pgd
= pgd_offset_k(address
);
636 p4d
= p4d_offset(pgd
, address
);
637 if (p4d_none(*p4d
) || p4d_large(*p4d
) || !p4d_present(*p4d
))
640 pud
= pud_offset(p4d
, address
);
641 if (pud_none(*pud
) || pud_large(*pud
) || !pud_present(*pud
))
644 return pmd_offset(pud
, address
);
648 * This is necessary because __pa() does not work on some
649 * kinds of memory, like vmalloc() or the alloc_remap()
650 * areas on 32-bit NUMA systems. The percpu areas can
651 * end up in this kind of memory, for instance.
653 * This could be optimized, but it is only intended to be
654 * used at inititalization time, and keeping it
655 * unoptimized should increase the testing coverage for
656 * the more obscure platforms.
658 phys_addr_t
slow_virt_to_phys(void *__virt_addr
)
660 unsigned long virt_addr
= (unsigned long)__virt_addr
;
661 phys_addr_t phys_addr
;
662 unsigned long offset
;
666 pte
= lookup_address(virt_addr
, &level
);
670 * pXX_pfn() returns unsigned long, which must be cast to phys_addr_t
671 * before being left-shifted PAGE_SHIFT bits -- this trick is to
672 * make 32-PAE kernel work correctly.
676 phys_addr
= (phys_addr_t
)pud_pfn(*(pud_t
*)pte
) << PAGE_SHIFT
;
677 offset
= virt_addr
& ~PUD_PAGE_MASK
;
680 phys_addr
= (phys_addr_t
)pmd_pfn(*(pmd_t
*)pte
) << PAGE_SHIFT
;
681 offset
= virt_addr
& ~PMD_PAGE_MASK
;
684 phys_addr
= (phys_addr_t
)pte_pfn(*pte
) << PAGE_SHIFT
;
685 offset
= virt_addr
& ~PAGE_MASK
;
688 return (phys_addr_t
)(phys_addr
| offset
);
690 EXPORT_SYMBOL_GPL(slow_virt_to_phys
);
693 * Set the new pmd in all the pgds we know about:
695 static void __set_pmd_pte(pte_t
*kpte
, unsigned long address
, pte_t pte
)
698 set_pte_atomic(kpte
, pte
);
700 if (!SHARED_KERNEL_PMD
) {
703 list_for_each_entry(page
, &pgd_list
, lru
) {
709 pgd
= (pgd_t
*)page_address(page
) + pgd_index(address
);
710 p4d
= p4d_offset(pgd
, address
);
711 pud
= pud_offset(p4d
, address
);
712 pmd
= pmd_offset(pud
, address
);
713 set_pte_atomic((pte_t
*)pmd
, pte
);
719 static pgprot_t
pgprot_clear_protnone_bits(pgprot_t prot
)
722 * _PAGE_GLOBAL means "global page" for present PTEs.
723 * But, it is also used to indicate _PAGE_PROTNONE
724 * for non-present PTEs.
726 * This ensures that a _PAGE_GLOBAL PTE going from
727 * present to non-present is not confused as
730 if (!(pgprot_val(prot
) & _PAGE_PRESENT
))
731 pgprot_val(prot
) &= ~_PAGE_GLOBAL
;
736 static int __should_split_large_page(pte_t
*kpte
, unsigned long address
,
737 struct cpa_data
*cpa
)
739 unsigned long numpages
, pmask
, psize
, lpaddr
, pfn
, old_pfn
;
740 pgprot_t old_prot
, new_prot
, req_prot
, chk_prot
;
745 * Check for races, another CPU might have split this page
748 tmp
= _lookup_address_cpa(cpa
, address
, &level
);
754 old_prot
= pmd_pgprot(*(pmd_t
*)kpte
);
755 old_pfn
= pmd_pfn(*(pmd_t
*)kpte
);
756 cpa_inc_2m_checked();
759 old_prot
= pud_pgprot(*(pud_t
*)kpte
);
760 old_pfn
= pud_pfn(*(pud_t
*)kpte
);
761 cpa_inc_1g_checked();
767 psize
= page_level_size(level
);
768 pmask
= page_level_mask(level
);
771 * Calculate the number of pages, which fit into this large
772 * page starting at address:
774 lpaddr
= (address
+ psize
) & pmask
;
775 numpages
= (lpaddr
- address
) >> PAGE_SHIFT
;
776 if (numpages
< cpa
->numpages
)
777 cpa
->numpages
= numpages
;
780 * We are safe now. Check whether the new pgprot is the same:
781 * Convert protection attributes to 4k-format, as cpa->mask* are set
785 /* Clear PSE (aka _PAGE_PAT) and move PAT bit to correct position */
786 req_prot
= pgprot_large_2_4k(old_prot
);
788 pgprot_val(req_prot
) &= ~pgprot_val(cpa
->mask_clr
);
789 pgprot_val(req_prot
) |= pgprot_val(cpa
->mask_set
);
792 * req_prot is in format of 4k pages. It must be converted to large
793 * page format: the caching mode includes the PAT bit located at
794 * different bit positions in the two formats.
796 req_prot
= pgprot_4k_2_large(req_prot
);
797 req_prot
= pgprot_clear_protnone_bits(req_prot
);
798 if (pgprot_val(req_prot
) & _PAGE_PRESENT
)
799 pgprot_val(req_prot
) |= _PAGE_PSE
;
802 * old_pfn points to the large page base pfn. So we need to add the
803 * offset of the virtual address:
805 pfn
= old_pfn
+ ((address
& (psize
- 1)) >> PAGE_SHIFT
);
809 * Calculate the large page base address and the number of 4K pages
812 lpaddr
= address
& pmask
;
813 numpages
= psize
>> PAGE_SHIFT
;
816 * Sanity check that the existing mapping is correct versus the static
817 * protections. static_protections() guards against !PRESENT, so no
818 * extra conditional required here.
820 chk_prot
= static_protections(old_prot
, lpaddr
, old_pfn
, numpages
,
823 if (WARN_ON_ONCE(pgprot_val(chk_prot
) != pgprot_val(old_prot
))) {
825 * Split the large page and tell the split code to
826 * enforce static protections.
828 cpa
->force_static_prot
= 1;
833 * Optimization: If the requested pgprot is the same as the current
834 * pgprot, then the large page can be preserved and no updates are
835 * required independent of alignment and length of the requested
836 * range. The above already established that the current pgprot is
837 * correct, which in consequence makes the requested pgprot correct
838 * as well if it is the same. The static protection scan below will
839 * not come to a different conclusion.
841 if (pgprot_val(req_prot
) == pgprot_val(old_prot
)) {
842 cpa_inc_lp_sameprot(level
);
847 * If the requested range does not cover the full page, split it up
849 if (address
!= lpaddr
|| cpa
->numpages
!= numpages
)
853 * Check whether the requested pgprot is conflicting with a static
854 * protection requirement in the large page.
856 new_prot
= static_protections(req_prot
, lpaddr
, old_pfn
, numpages
,
860 * If there is a conflict, split the large page.
862 * There used to be a 4k wise evaluation trying really hard to
863 * preserve the large pages, but experimentation has shown, that this
864 * does not help at all. There might be corner cases which would
865 * preserve one large page occasionally, but it's really not worth the
866 * extra code and cycles for the common case.
868 if (pgprot_val(req_prot
) != pgprot_val(new_prot
))
871 /* All checks passed. Update the large page mapping. */
872 new_pte
= pfn_pte(old_pfn
, new_prot
);
873 __set_pmd_pte(kpte
, address
, new_pte
);
874 cpa
->flags
|= CPA_FLUSHTLB
;
875 cpa_inc_lp_preserved(level
);
879 static int should_split_large_page(pte_t
*kpte
, unsigned long address
,
880 struct cpa_data
*cpa
)
884 if (cpa
->force_split
)
887 spin_lock(&pgd_lock
);
888 do_split
= __should_split_large_page(kpte
, address
, cpa
);
889 spin_unlock(&pgd_lock
);
894 static void split_set_pte(struct cpa_data
*cpa
, pte_t
*pte
, unsigned long pfn
,
895 pgprot_t ref_prot
, unsigned long address
,
898 unsigned int npg
= PFN_DOWN(size
);
902 * If should_split_large_page() discovered an inconsistent mapping,
903 * remove the invalid protection in the split mapping.
905 if (!cpa
->force_static_prot
)
908 prot
= static_protections(ref_prot
, address
, pfn
, npg
, CPA_PROTECT
);
910 if (pgprot_val(prot
) == pgprot_val(ref_prot
))
914 * If this is splitting a PMD, fix it up. PUD splits cannot be
915 * fixed trivially as that would require to rescan the newly
916 * installed PMD mappings after returning from split_large_page()
917 * so an eventual further split can allocate the necessary PTE
918 * pages. Warn for now and revisit it in case this actually
921 if (size
== PAGE_SIZE
)
924 pr_warn_once("CPA: Cannot fixup static protections for PUD split\n");
926 set_pte(pte
, pfn_pte(pfn
, ref_prot
));
930 __split_large_page(struct cpa_data
*cpa
, pte_t
*kpte
, unsigned long address
,
933 unsigned long lpaddr
, lpinc
, ref_pfn
, pfn
, pfninc
= 1;
934 pte_t
*pbase
= (pte_t
*)page_address(base
);
935 unsigned int i
, level
;
939 spin_lock(&pgd_lock
);
941 * Check for races, another CPU might have split this page
944 tmp
= _lookup_address_cpa(cpa
, address
, &level
);
946 spin_unlock(&pgd_lock
);
950 paravirt_alloc_pte(&init_mm
, page_to_pfn(base
));
954 ref_prot
= pmd_pgprot(*(pmd_t
*)kpte
);
956 * Clear PSE (aka _PAGE_PAT) and move
957 * PAT bit to correct position.
959 ref_prot
= pgprot_large_2_4k(ref_prot
);
960 ref_pfn
= pmd_pfn(*(pmd_t
*)kpte
);
961 lpaddr
= address
& PMD_MASK
;
966 ref_prot
= pud_pgprot(*(pud_t
*)kpte
);
967 ref_pfn
= pud_pfn(*(pud_t
*)kpte
);
968 pfninc
= PMD_PAGE_SIZE
>> PAGE_SHIFT
;
969 lpaddr
= address
& PUD_MASK
;
972 * Clear the PSE flags if the PRESENT flag is not set
973 * otherwise pmd_present/pmd_huge will return true
974 * even on a non present pmd.
976 if (!(pgprot_val(ref_prot
) & _PAGE_PRESENT
))
977 pgprot_val(ref_prot
) &= ~_PAGE_PSE
;
981 spin_unlock(&pgd_lock
);
985 ref_prot
= pgprot_clear_protnone_bits(ref_prot
);
988 * Get the target pfn from the original entry:
991 for (i
= 0; i
< PTRS_PER_PTE
; i
++, pfn
+= pfninc
, lpaddr
+= lpinc
)
992 split_set_pte(cpa
, pbase
+ i
, pfn
, ref_prot
, lpaddr
, lpinc
);
994 if (virt_addr_valid(address
)) {
995 unsigned long pfn
= PFN_DOWN(__pa(address
));
997 if (pfn_range_is_mapped(pfn
, pfn
+ 1))
998 split_page_count(level
);
1002 * Install the new, split up pagetable.
1004 * We use the standard kernel pagetable protections for the new
1005 * pagetable protections, the actual ptes set above control the
1006 * primary protection behavior:
1008 __set_pmd_pte(kpte
, address
, mk_pte(base
, __pgprot(_KERNPG_TABLE
)));
1011 * Do a global flush tlb after splitting the large page
1012 * and before we do the actual change page attribute in the PTE.
1014 * Without this, we violate the TLB application note, that says:
1015 * "The TLBs may contain both ordinary and large-page
1016 * translations for a 4-KByte range of linear addresses. This
1017 * may occur if software modifies the paging structures so that
1018 * the page size used for the address range changes. If the two
1019 * translations differ with respect to page frame or attributes
1020 * (e.g., permissions), processor behavior is undefined and may
1021 * be implementation-specific."
1023 * We do this global tlb flush inside the cpa_lock, so that we
1024 * don't allow any other cpu, with stale tlb entries change the
1025 * page attribute in parallel, that also falls into the
1026 * just split large page entry.
1029 spin_unlock(&pgd_lock
);
1034 static int split_large_page(struct cpa_data
*cpa
, pte_t
*kpte
,
1035 unsigned long address
)
1039 if (!debug_pagealloc_enabled())
1040 spin_unlock(&cpa_lock
);
1041 base
= alloc_pages(GFP_KERNEL
, 0);
1042 if (!debug_pagealloc_enabled())
1043 spin_lock(&cpa_lock
);
1047 if (__split_large_page(cpa
, kpte
, address
, base
))
1053 static bool try_to_free_pte_page(pte_t
*pte
)
1057 for (i
= 0; i
< PTRS_PER_PTE
; i
++)
1058 if (!pte_none(pte
[i
]))
1061 free_page((unsigned long)pte
);
1065 static bool try_to_free_pmd_page(pmd_t
*pmd
)
1069 for (i
= 0; i
< PTRS_PER_PMD
; i
++)
1070 if (!pmd_none(pmd
[i
]))
1073 free_page((unsigned long)pmd
);
1077 static bool unmap_pte_range(pmd_t
*pmd
, unsigned long start
, unsigned long end
)
1079 pte_t
*pte
= pte_offset_kernel(pmd
, start
);
1081 while (start
< end
) {
1082 set_pte(pte
, __pte(0));
1088 if (try_to_free_pte_page((pte_t
*)pmd_page_vaddr(*pmd
))) {
1095 static void __unmap_pmd_range(pud_t
*pud
, pmd_t
*pmd
,
1096 unsigned long start
, unsigned long end
)
1098 if (unmap_pte_range(pmd
, start
, end
))
1099 if (try_to_free_pmd_page((pmd_t
*)pud_page_vaddr(*pud
)))
1103 static void unmap_pmd_range(pud_t
*pud
, unsigned long start
, unsigned long end
)
1105 pmd_t
*pmd
= pmd_offset(pud
, start
);
1108 * Not on a 2MB page boundary?
1110 if (start
& (PMD_SIZE
- 1)) {
1111 unsigned long next_page
= (start
+ PMD_SIZE
) & PMD_MASK
;
1112 unsigned long pre_end
= min_t(unsigned long, end
, next_page
);
1114 __unmap_pmd_range(pud
, pmd
, start
, pre_end
);
1121 * Try to unmap in 2M chunks.
1123 while (end
- start
>= PMD_SIZE
) {
1124 if (pmd_large(*pmd
))
1127 __unmap_pmd_range(pud
, pmd
, start
, start
+ PMD_SIZE
);
1137 return __unmap_pmd_range(pud
, pmd
, start
, end
);
1140 * Try again to free the PMD page if haven't succeeded above.
1142 if (!pud_none(*pud
))
1143 if (try_to_free_pmd_page((pmd_t
*)pud_page_vaddr(*pud
)))
1147 static void unmap_pud_range(p4d_t
*p4d
, unsigned long start
, unsigned long end
)
1149 pud_t
*pud
= pud_offset(p4d
, start
);
1152 * Not on a GB page boundary?
1154 if (start
& (PUD_SIZE
- 1)) {
1155 unsigned long next_page
= (start
+ PUD_SIZE
) & PUD_MASK
;
1156 unsigned long pre_end
= min_t(unsigned long, end
, next_page
);
1158 unmap_pmd_range(pud
, start
, pre_end
);
1165 * Try to unmap in 1G chunks?
1167 while (end
- start
>= PUD_SIZE
) {
1169 if (pud_large(*pud
))
1172 unmap_pmd_range(pud
, start
, start
+ PUD_SIZE
);
1182 unmap_pmd_range(pud
, start
, end
);
1185 * No need to try to free the PUD page because we'll free it in
1186 * populate_pgd's error path
1190 static int alloc_pte_page(pmd_t
*pmd
)
1192 pte_t
*pte
= (pte_t
*)get_zeroed_page(GFP_KERNEL
);
1196 set_pmd(pmd
, __pmd(__pa(pte
) | _KERNPG_TABLE
));
1200 static int alloc_pmd_page(pud_t
*pud
)
1202 pmd_t
*pmd
= (pmd_t
*)get_zeroed_page(GFP_KERNEL
);
1206 set_pud(pud
, __pud(__pa(pmd
) | _KERNPG_TABLE
));
1210 static void populate_pte(struct cpa_data
*cpa
,
1211 unsigned long start
, unsigned long end
,
1212 unsigned num_pages
, pmd_t
*pmd
, pgprot_t pgprot
)
1216 pte
= pte_offset_kernel(pmd
, start
);
1218 pgprot
= pgprot_clear_protnone_bits(pgprot
);
1220 while (num_pages
-- && start
< end
) {
1221 set_pte(pte
, pfn_pte(cpa
->pfn
, pgprot
));
1229 static long populate_pmd(struct cpa_data
*cpa
,
1230 unsigned long start
, unsigned long end
,
1231 unsigned num_pages
, pud_t
*pud
, pgprot_t pgprot
)
1235 pgprot_t pmd_pgprot
;
1238 * Not on a 2M boundary?
1240 if (start
& (PMD_SIZE
- 1)) {
1241 unsigned long pre_end
= start
+ (num_pages
<< PAGE_SHIFT
);
1242 unsigned long next_page
= (start
+ PMD_SIZE
) & PMD_MASK
;
1244 pre_end
= min_t(unsigned long, pre_end
, next_page
);
1245 cur_pages
= (pre_end
- start
) >> PAGE_SHIFT
;
1246 cur_pages
= min_t(unsigned int, num_pages
, cur_pages
);
1251 pmd
= pmd_offset(pud
, start
);
1253 if (alloc_pte_page(pmd
))
1256 populate_pte(cpa
, start
, pre_end
, cur_pages
, pmd
, pgprot
);
1262 * We mapped them all?
1264 if (num_pages
== cur_pages
)
1267 pmd_pgprot
= pgprot_4k_2_large(pgprot
);
1269 while (end
- start
>= PMD_SIZE
) {
1272 * We cannot use a 1G page so allocate a PMD page if needed.
1275 if (alloc_pmd_page(pud
))
1278 pmd
= pmd_offset(pud
, start
);
1280 set_pmd(pmd
, pmd_mkhuge(pfn_pmd(cpa
->pfn
,
1281 canon_pgprot(pmd_pgprot
))));
1284 cpa
->pfn
+= PMD_SIZE
>> PAGE_SHIFT
;
1285 cur_pages
+= PMD_SIZE
>> PAGE_SHIFT
;
1289 * Map trailing 4K pages.
1292 pmd
= pmd_offset(pud
, start
);
1294 if (alloc_pte_page(pmd
))
1297 populate_pte(cpa
, start
, end
, num_pages
- cur_pages
,
1303 static int populate_pud(struct cpa_data
*cpa
, unsigned long start
, p4d_t
*p4d
,
1309 pgprot_t pud_pgprot
;
1311 end
= start
+ (cpa
->numpages
<< PAGE_SHIFT
);
1314 * Not on a Gb page boundary? => map everything up to it with
1317 if (start
& (PUD_SIZE
- 1)) {
1318 unsigned long pre_end
;
1319 unsigned long next_page
= (start
+ PUD_SIZE
) & PUD_MASK
;
1321 pre_end
= min_t(unsigned long, end
, next_page
);
1322 cur_pages
= (pre_end
- start
) >> PAGE_SHIFT
;
1323 cur_pages
= min_t(int, (int)cpa
->numpages
, cur_pages
);
1325 pud
= pud_offset(p4d
, start
);
1331 if (alloc_pmd_page(pud
))
1334 cur_pages
= populate_pmd(cpa
, start
, pre_end
, cur_pages
,
1342 /* We mapped them all? */
1343 if (cpa
->numpages
== cur_pages
)
1346 pud
= pud_offset(p4d
, start
);
1347 pud_pgprot
= pgprot_4k_2_large(pgprot
);
1350 * Map everything starting from the Gb boundary, possibly with 1G pages
1352 while (boot_cpu_has(X86_FEATURE_GBPAGES
) && end
- start
>= PUD_SIZE
) {
1353 set_pud(pud
, pud_mkhuge(pfn_pud(cpa
->pfn
,
1354 canon_pgprot(pud_pgprot
))));
1357 cpa
->pfn
+= PUD_SIZE
>> PAGE_SHIFT
;
1358 cur_pages
+= PUD_SIZE
>> PAGE_SHIFT
;
1362 /* Map trailing leftover */
1366 pud
= pud_offset(p4d
, start
);
1368 if (alloc_pmd_page(pud
))
1371 tmp
= populate_pmd(cpa
, start
, end
, cpa
->numpages
- cur_pages
,
1382 * Restrictions for kernel page table do not necessarily apply when mapping in
1385 static int populate_pgd(struct cpa_data
*cpa
, unsigned long addr
)
1387 pgprot_t pgprot
= __pgprot(_KERNPG_TABLE
);
1388 pud_t
*pud
= NULL
; /* shut up gcc */
1393 pgd_entry
= cpa
->pgd
+ pgd_index(addr
);
1395 if (pgd_none(*pgd_entry
)) {
1396 p4d
= (p4d_t
*)get_zeroed_page(GFP_KERNEL
);
1400 set_pgd(pgd_entry
, __pgd(__pa(p4d
) | _KERNPG_TABLE
));
1404 * Allocate a PUD page and hand it down for mapping.
1406 p4d
= p4d_offset(pgd_entry
, addr
);
1407 if (p4d_none(*p4d
)) {
1408 pud
= (pud_t
*)get_zeroed_page(GFP_KERNEL
);
1412 set_p4d(p4d
, __p4d(__pa(pud
) | _KERNPG_TABLE
));
1415 pgprot_val(pgprot
) &= ~pgprot_val(cpa
->mask_clr
);
1416 pgprot_val(pgprot
) |= pgprot_val(cpa
->mask_set
);
1418 ret
= populate_pud(cpa
, addr
, p4d
, pgprot
);
1421 * Leave the PUD page in place in case some other CPU or thread
1422 * already found it, but remove any useless entries we just
1425 unmap_pud_range(p4d
, addr
,
1426 addr
+ (cpa
->numpages
<< PAGE_SHIFT
));
1430 cpa
->numpages
= ret
;
1434 static int __cpa_process_fault(struct cpa_data
*cpa
, unsigned long vaddr
,
1439 * Right now, we only execute this code path when mapping
1440 * the EFI virtual memory map regions, no other users
1441 * provide a ->pgd value. This may change in the future.
1443 return populate_pgd(cpa
, vaddr
);
1447 * Ignore all non primary paths.
1455 * Ignore the NULL PTE for kernel identity mapping, as it is expected
1457 * Also set numpages to '1' indicating that we processed cpa req for
1458 * one virtual address page and its pfn. TBD: numpages can be set based
1459 * on the initial value and the level returned by lookup_address().
1461 if (within(vaddr
, PAGE_OFFSET
,
1462 PAGE_OFFSET
+ (max_pfn_mapped
<< PAGE_SHIFT
))) {
1464 cpa
->pfn
= __pa(vaddr
) >> PAGE_SHIFT
;
1467 } else if (__cpa_pfn_in_highmap(cpa
->pfn
)) {
1468 /* Faults in the highmap are OK, so do not warn: */
1471 WARN(1, KERN_WARNING
"CPA: called for zero pte. "
1472 "vaddr = %lx cpa->vaddr = %lx\n", vaddr
,
1479 static int __change_page_attr(struct cpa_data
*cpa
, int primary
)
1481 unsigned long address
;
1484 pte_t
*kpte
, old_pte
;
1486 address
= __cpa_addr(cpa
, cpa
->curpage
);
1488 kpte
= _lookup_address_cpa(cpa
, address
, &level
);
1490 return __cpa_process_fault(cpa
, address
, primary
);
1493 if (pte_none(old_pte
))
1494 return __cpa_process_fault(cpa
, address
, primary
);
1496 if (level
== PG_LEVEL_4K
) {
1498 pgprot_t new_prot
= pte_pgprot(old_pte
);
1499 unsigned long pfn
= pte_pfn(old_pte
);
1501 pgprot_val(new_prot
) &= ~pgprot_val(cpa
->mask_clr
);
1502 pgprot_val(new_prot
) |= pgprot_val(cpa
->mask_set
);
1504 cpa_inc_4k_install();
1505 new_prot
= static_protections(new_prot
, address
, pfn
, 1,
1508 new_prot
= pgprot_clear_protnone_bits(new_prot
);
1511 * We need to keep the pfn from the existing PTE,
1512 * after all we're only going to change it's attributes
1513 * not the memory it points to
1515 new_pte
= pfn_pte(pfn
, new_prot
);
1518 * Do we really change anything ?
1520 if (pte_val(old_pte
) != pte_val(new_pte
)) {
1521 set_pte_atomic(kpte
, new_pte
);
1522 cpa
->flags
|= CPA_FLUSHTLB
;
1529 * Check, whether we can keep the large page intact
1530 * and just change the pte:
1532 do_split
= should_split_large_page(kpte
, address
, cpa
);
1534 * When the range fits into the existing large page,
1535 * return. cp->numpages and cpa->tlbflush have been updated in
1542 * We have to split the large page:
1544 err
= split_large_page(cpa
, kpte
, address
);
1551 static int __change_page_attr_set_clr(struct cpa_data
*cpa
, int checkalias
);
1553 static int cpa_process_alias(struct cpa_data
*cpa
)
1555 struct cpa_data alias_cpa
;
1556 unsigned long laddr
= (unsigned long)__va(cpa
->pfn
<< PAGE_SHIFT
);
1557 unsigned long vaddr
;
1560 if (!pfn_range_is_mapped(cpa
->pfn
, cpa
->pfn
+ 1))
1564 * No need to redo, when the primary call touched the direct
1567 vaddr
= __cpa_addr(cpa
, cpa
->curpage
);
1568 if (!(within(vaddr
, PAGE_OFFSET
,
1569 PAGE_OFFSET
+ (max_pfn_mapped
<< PAGE_SHIFT
)))) {
1572 alias_cpa
.vaddr
= &laddr
;
1573 alias_cpa
.flags
&= ~(CPA_PAGES_ARRAY
| CPA_ARRAY
);
1574 alias_cpa
.curpage
= 0;
1576 ret
= __change_page_attr_set_clr(&alias_cpa
, 0);
1581 #ifdef CONFIG_X86_64
1583 * If the primary call didn't touch the high mapping already
1584 * and the physical address is inside the kernel map, we need
1585 * to touch the high mapped kernel as well:
1587 if (!within(vaddr
, (unsigned long)_text
, _brk_end
) &&
1588 __cpa_pfn_in_highmap(cpa
->pfn
)) {
1589 unsigned long temp_cpa_vaddr
= (cpa
->pfn
<< PAGE_SHIFT
) +
1590 __START_KERNEL_map
- phys_base
;
1592 alias_cpa
.vaddr
= &temp_cpa_vaddr
;
1593 alias_cpa
.flags
&= ~(CPA_PAGES_ARRAY
| CPA_ARRAY
);
1594 alias_cpa
.curpage
= 0;
1597 * The high mapping range is imprecise, so ignore the
1600 __change_page_attr_set_clr(&alias_cpa
, 0);
1607 static int __change_page_attr_set_clr(struct cpa_data
*cpa
, int checkalias
)
1609 unsigned long numpages
= cpa
->numpages
;
1610 unsigned long rempages
= numpages
;
1615 * Store the remaining nr of pages for the large page
1616 * preservation check.
1618 cpa
->numpages
= rempages
;
1619 /* for array changes, we can't use large page */
1620 if (cpa
->flags
& (CPA_ARRAY
| CPA_PAGES_ARRAY
))
1623 if (!debug_pagealloc_enabled())
1624 spin_lock(&cpa_lock
);
1625 ret
= __change_page_attr(cpa
, checkalias
);
1626 if (!debug_pagealloc_enabled())
1627 spin_unlock(&cpa_lock
);
1632 ret
= cpa_process_alias(cpa
);
1638 * Adjust the number of pages with the result of the
1639 * CPA operation. Either a large page has been
1640 * preserved or a single page update happened.
1642 BUG_ON(cpa
->numpages
> rempages
|| !cpa
->numpages
);
1643 rempages
-= cpa
->numpages
;
1644 cpa
->curpage
+= cpa
->numpages
;
1648 /* Restore the original numpages */
1649 cpa
->numpages
= numpages
;
1653 static int change_page_attr_set_clr(unsigned long *addr
, int numpages
,
1654 pgprot_t mask_set
, pgprot_t mask_clr
,
1655 int force_split
, int in_flag
,
1656 struct page
**pages
)
1658 struct cpa_data cpa
;
1659 int ret
, cache
, checkalias
;
1661 memset(&cpa
, 0, sizeof(cpa
));
1664 * Check, if we are requested to set a not supported
1665 * feature. Clearing non-supported features is OK.
1667 mask_set
= canon_pgprot(mask_set
);
1669 if (!pgprot_val(mask_set
) && !pgprot_val(mask_clr
) && !force_split
)
1672 /* Ensure we are PAGE_SIZE aligned */
1673 if (in_flag
& CPA_ARRAY
) {
1675 for (i
= 0; i
< numpages
; i
++) {
1676 if (addr
[i
] & ~PAGE_MASK
) {
1677 addr
[i
] &= PAGE_MASK
;
1681 } else if (!(in_flag
& CPA_PAGES_ARRAY
)) {
1683 * in_flag of CPA_PAGES_ARRAY implies it is aligned.
1684 * No need to check in that case
1686 if (*addr
& ~PAGE_MASK
) {
1689 * People should not be passing in unaligned addresses:
1695 /* Must avoid aliasing mappings in the highmem code */
1696 kmap_flush_unused();
1702 cpa
.numpages
= numpages
;
1703 cpa
.mask_set
= mask_set
;
1704 cpa
.mask_clr
= mask_clr
;
1707 cpa
.force_split
= force_split
;
1709 if (in_flag
& (CPA_ARRAY
| CPA_PAGES_ARRAY
))
1710 cpa
.flags
|= in_flag
;
1712 /* No alias checking for _NX bit modifications */
1713 checkalias
= (pgprot_val(mask_set
) | pgprot_val(mask_clr
)) != _PAGE_NX
;
1714 /* Has caller explicitly disabled alias checking? */
1715 if (in_flag
& CPA_NO_CHECK_ALIAS
)
1718 ret
= __change_page_attr_set_clr(&cpa
, checkalias
);
1721 * Check whether we really changed something:
1723 if (!(cpa
.flags
& CPA_FLUSHTLB
))
1727 * No need to flush, when we did not set any of the caching
1730 cache
= !!pgprot2cachemode(mask_set
);
1733 * On error; flush everything to be sure.
1736 cpa_flush_all(cache
);
1740 cpa_flush(&cpa
, cache
);
1745 static inline int change_page_attr_set(unsigned long *addr
, int numpages
,
1746 pgprot_t mask
, int array
)
1748 return change_page_attr_set_clr(addr
, numpages
, mask
, __pgprot(0), 0,
1749 (array
? CPA_ARRAY
: 0), NULL
);
1752 static inline int change_page_attr_clear(unsigned long *addr
, int numpages
,
1753 pgprot_t mask
, int array
)
1755 return change_page_attr_set_clr(addr
, numpages
, __pgprot(0), mask
, 0,
1756 (array
? CPA_ARRAY
: 0), NULL
);
1759 static inline int cpa_set_pages_array(struct page
**pages
, int numpages
,
1762 return change_page_attr_set_clr(NULL
, numpages
, mask
, __pgprot(0), 0,
1763 CPA_PAGES_ARRAY
, pages
);
1766 static inline int cpa_clear_pages_array(struct page
**pages
, int numpages
,
1769 return change_page_attr_set_clr(NULL
, numpages
, __pgprot(0), mask
, 0,
1770 CPA_PAGES_ARRAY
, pages
);
1773 int _set_memory_uc(unsigned long addr
, int numpages
)
1776 * for now UC MINUS. see comments in ioremap_nocache()
1777 * If you really need strong UC use ioremap_uc(), but note
1778 * that you cannot override IO areas with set_memory_*() as
1779 * these helpers cannot work with IO memory.
1781 return change_page_attr_set(&addr
, numpages
,
1782 cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS
),
1786 int set_memory_uc(unsigned long addr
, int numpages
)
1791 * for now UC MINUS. see comments in ioremap_nocache()
1793 ret
= reserve_memtype(__pa(addr
), __pa(addr
) + numpages
* PAGE_SIZE
,
1794 _PAGE_CACHE_MODE_UC_MINUS
, NULL
);
1798 ret
= _set_memory_uc(addr
, numpages
);
1805 free_memtype(__pa(addr
), __pa(addr
) + numpages
* PAGE_SIZE
);
1809 EXPORT_SYMBOL(set_memory_uc
);
1811 static int _set_memory_array(unsigned long *addr
, int numpages
,
1812 enum page_cache_mode new_type
)
1814 enum page_cache_mode set_type
;
1818 for (i
= 0; i
< numpages
; i
++) {
1819 ret
= reserve_memtype(__pa(addr
[i
]), __pa(addr
[i
]) + PAGE_SIZE
,
1825 /* If WC, set to UC- first and then WC */
1826 set_type
= (new_type
== _PAGE_CACHE_MODE_WC
) ?
1827 _PAGE_CACHE_MODE_UC_MINUS
: new_type
;
1829 ret
= change_page_attr_set(addr
, numpages
,
1830 cachemode2pgprot(set_type
), 1);
1832 if (!ret
&& new_type
== _PAGE_CACHE_MODE_WC
)
1833 ret
= change_page_attr_set_clr(addr
, numpages
,
1835 _PAGE_CACHE_MODE_WC
),
1836 __pgprot(_PAGE_CACHE_MASK
),
1837 0, CPA_ARRAY
, NULL
);
1844 for (j
= 0; j
< i
; j
++)
1845 free_memtype(__pa(addr
[j
]), __pa(addr
[j
]) + PAGE_SIZE
);
1850 int set_memory_array_uc(unsigned long *addr
, int numpages
)
1852 return _set_memory_array(addr
, numpages
, _PAGE_CACHE_MODE_UC_MINUS
);
1854 EXPORT_SYMBOL(set_memory_array_uc
);
1856 int set_memory_array_wc(unsigned long *addr
, int numpages
)
1858 return _set_memory_array(addr
, numpages
, _PAGE_CACHE_MODE_WC
);
1860 EXPORT_SYMBOL(set_memory_array_wc
);
1862 int set_memory_array_wt(unsigned long *addr
, int numpages
)
1864 return _set_memory_array(addr
, numpages
, _PAGE_CACHE_MODE_WT
);
1866 EXPORT_SYMBOL_GPL(set_memory_array_wt
);
1868 int _set_memory_wc(unsigned long addr
, int numpages
)
1872 ret
= change_page_attr_set(&addr
, numpages
,
1873 cachemode2pgprot(_PAGE_CACHE_MODE_UC_MINUS
),
1876 ret
= change_page_attr_set_clr(&addr
, numpages
,
1877 cachemode2pgprot(_PAGE_CACHE_MODE_WC
),
1878 __pgprot(_PAGE_CACHE_MASK
),
1884 int set_memory_wc(unsigned long addr
, int numpages
)
1888 ret
= reserve_memtype(__pa(addr
), __pa(addr
) + numpages
* PAGE_SIZE
,
1889 _PAGE_CACHE_MODE_WC
, NULL
);
1893 ret
= _set_memory_wc(addr
, numpages
);
1895 free_memtype(__pa(addr
), __pa(addr
) + numpages
* PAGE_SIZE
);
1899 EXPORT_SYMBOL(set_memory_wc
);
1901 int _set_memory_wt(unsigned long addr
, int numpages
)
1903 return change_page_attr_set(&addr
, numpages
,
1904 cachemode2pgprot(_PAGE_CACHE_MODE_WT
), 0);
1907 int set_memory_wt(unsigned long addr
, int numpages
)
1911 ret
= reserve_memtype(__pa(addr
), __pa(addr
) + numpages
* PAGE_SIZE
,
1912 _PAGE_CACHE_MODE_WT
, NULL
);
1916 ret
= _set_memory_wt(addr
, numpages
);
1918 free_memtype(__pa(addr
), __pa(addr
) + numpages
* PAGE_SIZE
);
1922 EXPORT_SYMBOL_GPL(set_memory_wt
);
1924 int _set_memory_wb(unsigned long addr
, int numpages
)
1926 /* WB cache mode is hard wired to all cache attribute bits being 0 */
1927 return change_page_attr_clear(&addr
, numpages
,
1928 __pgprot(_PAGE_CACHE_MASK
), 0);
1931 int set_memory_wb(unsigned long addr
, int numpages
)
1935 ret
= _set_memory_wb(addr
, numpages
);
1939 free_memtype(__pa(addr
), __pa(addr
) + numpages
* PAGE_SIZE
);
1942 EXPORT_SYMBOL(set_memory_wb
);
1944 int set_memory_array_wb(unsigned long *addr
, int numpages
)
1949 /* WB cache mode is hard wired to all cache attribute bits being 0 */
1950 ret
= change_page_attr_clear(addr
, numpages
,
1951 __pgprot(_PAGE_CACHE_MASK
), 1);
1955 for (i
= 0; i
< numpages
; i
++)
1956 free_memtype(__pa(addr
[i
]), __pa(addr
[i
]) + PAGE_SIZE
);
1960 EXPORT_SYMBOL(set_memory_array_wb
);
1962 int set_memory_x(unsigned long addr
, int numpages
)
1964 if (!(__supported_pte_mask
& _PAGE_NX
))
1967 return change_page_attr_clear(&addr
, numpages
, __pgprot(_PAGE_NX
), 0);
1969 EXPORT_SYMBOL(set_memory_x
);
1971 int set_memory_nx(unsigned long addr
, int numpages
)
1973 if (!(__supported_pte_mask
& _PAGE_NX
))
1976 return change_page_attr_set(&addr
, numpages
, __pgprot(_PAGE_NX
), 0);
1978 EXPORT_SYMBOL(set_memory_nx
);
1980 int set_memory_ro(unsigned long addr
, int numpages
)
1982 return change_page_attr_clear(&addr
, numpages
, __pgprot(_PAGE_RW
), 0);
1985 int set_memory_rw(unsigned long addr
, int numpages
)
1987 return change_page_attr_set(&addr
, numpages
, __pgprot(_PAGE_RW
), 0);
1990 int set_memory_np(unsigned long addr
, int numpages
)
1992 return change_page_attr_clear(&addr
, numpages
, __pgprot(_PAGE_PRESENT
), 0);
1995 int set_memory_np_noalias(unsigned long addr
, int numpages
)
1997 int cpa_flags
= CPA_NO_CHECK_ALIAS
;
1999 return change_page_attr_set_clr(&addr
, numpages
, __pgprot(0),
2000 __pgprot(_PAGE_PRESENT
), 0,
2004 int set_memory_4k(unsigned long addr
, int numpages
)
2006 return change_page_attr_set_clr(&addr
, numpages
, __pgprot(0),
2007 __pgprot(0), 1, 0, NULL
);
2010 int set_memory_nonglobal(unsigned long addr
, int numpages
)
2012 return change_page_attr_clear(&addr
, numpages
,
2013 __pgprot(_PAGE_GLOBAL
), 0);
2016 int set_memory_global(unsigned long addr
, int numpages
)
2018 return change_page_attr_set(&addr
, numpages
,
2019 __pgprot(_PAGE_GLOBAL
), 0);
2022 static int __set_memory_enc_dec(unsigned long addr
, int numpages
, bool enc
)
2024 struct cpa_data cpa
;
2027 /* Nothing to do if memory encryption is not active */
2028 if (!mem_encrypt_active())
2031 /* Should not be working on unaligned addresses */
2032 if (WARN_ONCE(addr
& ~PAGE_MASK
, "misaligned address: %#lx\n", addr
))
2035 memset(&cpa
, 0, sizeof(cpa
));
2037 cpa
.numpages
= numpages
;
2038 cpa
.mask_set
= enc
? __pgprot(_PAGE_ENC
) : __pgprot(0);
2039 cpa
.mask_clr
= enc
? __pgprot(0) : __pgprot(_PAGE_ENC
);
2040 cpa
.pgd
= init_mm
.pgd
;
2042 /* Must avoid aliasing mappings in the highmem code */
2043 kmap_flush_unused();
2047 * Before changing the encryption attribute, we need to flush caches.
2051 ret
= __change_page_attr_set_clr(&cpa
, 1);
2054 * After changing the encryption attribute, we need to flush TLBs again
2055 * in case any speculative TLB caching occurred (but no need to flush
2056 * caches again). We could just use cpa_flush_all(), but in case TLB
2057 * flushing gets optimized in the cpa_flush() path use the same logic
2065 int set_memory_encrypted(unsigned long addr
, int numpages
)
2067 return __set_memory_enc_dec(addr
, numpages
, true);
2069 EXPORT_SYMBOL_GPL(set_memory_encrypted
);
2071 int set_memory_decrypted(unsigned long addr
, int numpages
)
2073 return __set_memory_enc_dec(addr
, numpages
, false);
2075 EXPORT_SYMBOL_GPL(set_memory_decrypted
);
2077 int set_pages_uc(struct page
*page
, int numpages
)
2079 unsigned long addr
= (unsigned long)page_address(page
);
2081 return set_memory_uc(addr
, numpages
);
2083 EXPORT_SYMBOL(set_pages_uc
);
2085 static int _set_pages_array(struct page
**pages
, int numpages
,
2086 enum page_cache_mode new_type
)
2088 unsigned long start
;
2090 enum page_cache_mode set_type
;
2095 for (i
= 0; i
< numpages
; i
++) {
2096 if (PageHighMem(pages
[i
]))
2098 start
= page_to_pfn(pages
[i
]) << PAGE_SHIFT
;
2099 end
= start
+ PAGE_SIZE
;
2100 if (reserve_memtype(start
, end
, new_type
, NULL
))
2104 /* If WC, set to UC- first and then WC */
2105 set_type
= (new_type
== _PAGE_CACHE_MODE_WC
) ?
2106 _PAGE_CACHE_MODE_UC_MINUS
: new_type
;
2108 ret
= cpa_set_pages_array(pages
, numpages
,
2109 cachemode2pgprot(set_type
));
2110 if (!ret
&& new_type
== _PAGE_CACHE_MODE_WC
)
2111 ret
= change_page_attr_set_clr(NULL
, numpages
,
2113 _PAGE_CACHE_MODE_WC
),
2114 __pgprot(_PAGE_CACHE_MASK
),
2115 0, CPA_PAGES_ARRAY
, pages
);
2118 return 0; /* Success */
2121 for (i
= 0; i
< free_idx
; i
++) {
2122 if (PageHighMem(pages
[i
]))
2124 start
= page_to_pfn(pages
[i
]) << PAGE_SHIFT
;
2125 end
= start
+ PAGE_SIZE
;
2126 free_memtype(start
, end
);
2131 int set_pages_array_uc(struct page
**pages
, int numpages
)
2133 return _set_pages_array(pages
, numpages
, _PAGE_CACHE_MODE_UC_MINUS
);
2135 EXPORT_SYMBOL(set_pages_array_uc
);
2137 int set_pages_array_wc(struct page
**pages
, int numpages
)
2139 return _set_pages_array(pages
, numpages
, _PAGE_CACHE_MODE_WC
);
2141 EXPORT_SYMBOL(set_pages_array_wc
);
2143 int set_pages_array_wt(struct page
**pages
, int numpages
)
2145 return _set_pages_array(pages
, numpages
, _PAGE_CACHE_MODE_WT
);
2147 EXPORT_SYMBOL_GPL(set_pages_array_wt
);
2149 int set_pages_wb(struct page
*page
, int numpages
)
2151 unsigned long addr
= (unsigned long)page_address(page
);
2153 return set_memory_wb(addr
, numpages
);
2155 EXPORT_SYMBOL(set_pages_wb
);
2157 int set_pages_array_wb(struct page
**pages
, int numpages
)
2160 unsigned long start
;
2164 /* WB cache mode is hard wired to all cache attribute bits being 0 */
2165 retval
= cpa_clear_pages_array(pages
, numpages
,
2166 __pgprot(_PAGE_CACHE_MASK
));
2170 for (i
= 0; i
< numpages
; i
++) {
2171 if (PageHighMem(pages
[i
]))
2173 start
= page_to_pfn(pages
[i
]) << PAGE_SHIFT
;
2174 end
= start
+ PAGE_SIZE
;
2175 free_memtype(start
, end
);
2180 EXPORT_SYMBOL(set_pages_array_wb
);
2182 int set_pages_x(struct page
*page
, int numpages
)
2184 unsigned long addr
= (unsigned long)page_address(page
);
2186 return set_memory_x(addr
, numpages
);
2188 EXPORT_SYMBOL(set_pages_x
);
2190 int set_pages_nx(struct page
*page
, int numpages
)
2192 unsigned long addr
= (unsigned long)page_address(page
);
2194 return set_memory_nx(addr
, numpages
);
2196 EXPORT_SYMBOL(set_pages_nx
);
2198 int set_pages_ro(struct page
*page
, int numpages
)
2200 unsigned long addr
= (unsigned long)page_address(page
);
2202 return set_memory_ro(addr
, numpages
);
2205 int set_pages_rw(struct page
*page
, int numpages
)
2207 unsigned long addr
= (unsigned long)page_address(page
);
2209 return set_memory_rw(addr
, numpages
);
2212 #ifdef CONFIG_DEBUG_PAGEALLOC
2214 static int __set_pages_p(struct page
*page
, int numpages
)
2216 unsigned long tempaddr
= (unsigned long) page_address(page
);
2217 struct cpa_data cpa
= { .vaddr
= &tempaddr
,
2219 .numpages
= numpages
,
2220 .mask_set
= __pgprot(_PAGE_PRESENT
| _PAGE_RW
),
2221 .mask_clr
= __pgprot(0),
2225 * No alias checking needed for setting present flag. otherwise,
2226 * we may need to break large pages for 64-bit kernel text
2227 * mappings (this adds to complexity if we want to do this from
2228 * atomic context especially). Let's keep it simple!
2230 return __change_page_attr_set_clr(&cpa
, 0);
2233 static int __set_pages_np(struct page
*page
, int numpages
)
2235 unsigned long tempaddr
= (unsigned long) page_address(page
);
2236 struct cpa_data cpa
= { .vaddr
= &tempaddr
,
2238 .numpages
= numpages
,
2239 .mask_set
= __pgprot(0),
2240 .mask_clr
= __pgprot(_PAGE_PRESENT
| _PAGE_RW
),
2244 * No alias checking needed for setting not present flag. otherwise,
2245 * we may need to break large pages for 64-bit kernel text
2246 * mappings (this adds to complexity if we want to do this from
2247 * atomic context especially). Let's keep it simple!
2249 return __change_page_attr_set_clr(&cpa
, 0);
2252 void __kernel_map_pages(struct page
*page
, int numpages
, int enable
)
2254 if (PageHighMem(page
))
2257 debug_check_no_locks_freed(page_address(page
),
2258 numpages
* PAGE_SIZE
);
2262 * The return value is ignored as the calls cannot fail.
2263 * Large pages for identity mappings are not used at boot time
2264 * and hence no memory allocations during large page split.
2267 __set_pages_p(page
, numpages
);
2269 __set_pages_np(page
, numpages
);
2272 * We should perform an IPI and flush all tlbs,
2273 * but that can deadlock->flush only current cpu.
2274 * Preemption needs to be disabled around __flush_tlb_all() due to
2275 * CR3 reload in __native_flush_tlb().
2281 arch_flush_lazy_mmu_mode();
2284 #ifdef CONFIG_HIBERNATION
2286 bool kernel_page_present(struct page
*page
)
2291 if (PageHighMem(page
))
2294 pte
= lookup_address((unsigned long)page_address(page
), &level
);
2295 return (pte_val(*pte
) & _PAGE_PRESENT
);
2298 #endif /* CONFIG_HIBERNATION */
2300 #endif /* CONFIG_DEBUG_PAGEALLOC */
2302 int __init
kernel_map_pages_in_pgd(pgd_t
*pgd
, u64 pfn
, unsigned long address
,
2303 unsigned numpages
, unsigned long page_flags
)
2305 int retval
= -EINVAL
;
2307 struct cpa_data cpa
= {
2311 .numpages
= numpages
,
2312 .mask_set
= __pgprot(0),
2313 .mask_clr
= __pgprot(0),
2317 WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP");
2319 if (!(__supported_pte_mask
& _PAGE_NX
))
2322 if (!(page_flags
& _PAGE_NX
))
2323 cpa
.mask_clr
= __pgprot(_PAGE_NX
);
2325 if (!(page_flags
& _PAGE_RW
))
2326 cpa
.mask_clr
= __pgprot(_PAGE_RW
);
2328 if (!(page_flags
& _PAGE_ENC
))
2329 cpa
.mask_clr
= pgprot_encrypted(cpa
.mask_clr
);
2331 cpa
.mask_set
= __pgprot(_PAGE_PRESENT
| page_flags
);
2333 retval
= __change_page_attr_set_clr(&cpa
, 0);
2341 * __flush_tlb_all() flushes mappings only on current CPU and hence this
2342 * function shouldn't be used in an SMP environment. Presently, it's used only
2343 * during boot (way before smp_init()) by EFI subsystem and hence is ok.
2345 int __init
kernel_unmap_pages_in_pgd(pgd_t
*pgd
, unsigned long address
,
2346 unsigned long numpages
)
2351 * The typical sequence for unmapping is to find a pte through
2352 * lookup_address_in_pgd() (ideally, it should never return NULL because
2353 * the address is already mapped) and change it's protections. As pfn is
2354 * the *target* of a mapping, it's not useful while unmapping.
2356 struct cpa_data cpa
= {
2360 .numpages
= numpages
,
2361 .mask_set
= __pgprot(0),
2362 .mask_clr
= __pgprot(_PAGE_PRESENT
| _PAGE_RW
),
2366 WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP");
2368 retval
= __change_page_attr_set_clr(&cpa
, 0);
2375 * The testcases use internal knowledge of the implementation that shouldn't
2376 * be exposed to the rest of the kernel. Include these directly here.
2378 #ifdef CONFIG_CPA_DEBUG
2379 #include "pageattr-test.c"