arch/x86/include/asm/pgalloc.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_X86_PGALLOC_H
   3 #define _ASM_X86_PGALLOC_H
   4
   5 #include <linux/threads.h>
   6 #include <linux/mm.h>           /* for struct page */
   7 #include <linux/pagemap.h>
   8
   9 #define __HAVE_ARCH_PTE_ALLOC_ONE
  10 #define __HAVE_ARCH_PGD_FREE
  11 #include <asm-generic/pgalloc.h>
  12
  13 static inline int  __paravirt_pgd_alloc(struct mm_struct *mm) { return 0; }
  14
  15 #ifdef CONFIG_PARAVIRT_XXL
  16 #include <asm/paravirt.h>
  17 #else
  18 #define paravirt_pgd_alloc(mm)  __paravirt_pgd_alloc(mm)
  19 static inline void paravirt_pgd_free(struct mm_struct *mm, pgd_t *pgd) {}
  20 static inline void paravirt_alloc_pte(struct mm_struct *mm, unsigned long pfn)  {}
  21 static inline void paravirt_alloc_pmd(struct mm_struct *mm, unsigned long pfn)  {}
  22 static inline void paravirt_alloc_pmd_clone(unsigned long pfn, unsigned long clonepfn,
  23                                             unsigned long start, unsigned long count) {}
  24 static inline void paravirt_alloc_pud(struct mm_struct *mm, unsigned long pfn)  {}
  25 static inline void paravirt_alloc_p4d(struct mm_struct *mm, unsigned long pfn)  {}
  26 static inline void paravirt_release_pte(unsigned long pfn) {}
  27 static inline void paravirt_release_pmd(unsigned long pfn) {}
  28 static inline void paravirt_release_pud(unsigned long pfn) {}
  29 static inline void paravirt_release_p4d(unsigned long pfn) {}
  30 #endif
  31
  32 /*
  33  * Flags to use when allocating a user page table page.
  34  */
  35 extern gfp_t __userpte_alloc_gfp;
  36
  37 #ifdef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
  38 /*
  39  * Instead of one PGD, we acquire two PGDs.  Being order-1, it is
  40  * both 8k in size and 8k-aligned.  That lets us just flip bit 12
  41  * in a pointer to swap between the two 4k halves.
  42  */
  43 #define PGD_ALLOCATION_ORDER 1
  44 #else
  45 #define PGD_ALLOCATION_ORDER 0
  46 #endif
  47
  48 /*
  49  * Allocate and free page tables.
  50  */
  51 extern pgd_t *pgd_alloc(struct mm_struct *);
  52 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
  53
  54 extern pgtable_t pte_alloc_one(struct mm_struct *);
  55
  56 extern void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte);
  57
  58 static inline void __pte_free_tlb(struct mmu_gather *tlb, struct page *pte,
  59                                   unsigned long address)
  60 {
  61         ___pte_free_tlb(tlb, pte);
  62 }
  63
  64 static inline void pmd_populate_kernel(struct mm_struct *mm,
  65                                        pmd_t *pmd, pte_t *pte)
  66 {
  67         paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
  68         set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
  69 }
  70
  71 static inline void pmd_populate_kernel_safe(struct mm_struct *mm,
  72                                        pmd_t *pmd, pte_t *pte)
  73 {
  74         paravirt_alloc_pte(mm, __pa(pte) >> PAGE_SHIFT);
  75         set_pmd_safe(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
  76 }
  77
  78 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
  79                                 struct page *pte)
  80 {
  81         unsigned long pfn = page_to_pfn(pte);
  82
  83         paravirt_alloc_pte(mm, pfn);
  84         set_pmd(pmd, __pmd(((pteval_t)pfn << PAGE_SHIFT) | _PAGE_TABLE));
  85 }
  86
  87 #if CONFIG_PGTABLE_LEVELS > 2
  88 extern void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd);
  89
  90 static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
  91                                   unsigned long address)
  92 {
  93         ___pmd_free_tlb(tlb, pmd);
  94 }
  95
  96 #ifdef CONFIG_X86_PAE
  97 extern void pud_populate(struct mm_struct *mm, pud_t *pudp, pmd_t *pmd);
  98 #else   /* !CONFIG_X86_PAE */
  99 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 100 {
 101         paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
 102         set_pud(pud, __pud(_PAGE_TABLE | __pa(pmd)));
 103 }
 104
 105 static inline void pud_populate_safe(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 106 {
 107         paravirt_alloc_pmd(mm, __pa(pmd) >> PAGE_SHIFT);
 108         set_pud_safe(pud, __pud(_PAGE_TABLE | __pa(pmd)));
 109 }
 110 #endif  /* CONFIG_X86_PAE */
 111
 112 #if CONFIG_PGTABLE_LEVELS > 3
 113 static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
 114 {
 115         paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
 116         set_p4d(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
 117 }
 118
 119 static inline void p4d_populate_safe(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
 120 {
 121         paravirt_alloc_pud(mm, __pa(pud) >> PAGE_SHIFT);
 122         set_p4d_safe(p4d, __p4d(_PAGE_TABLE | __pa(pud)));
 123 }
 124
 125 extern void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud);
 126
 127 static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
 128                                   unsigned long address)
 129 {
 130         ___pud_free_tlb(tlb, pud);
 131 }
 132
 133 #if CONFIG_PGTABLE_LEVELS > 4
 134 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
 135 {
 136         if (!pgtable_l5_enabled())
 137                 return;
 138         paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
 139         set_pgd(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
 140 }
 141
 142 static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
 143 {
 144         if (!pgtable_l5_enabled())
 145                 return;
 146         paravirt_alloc_p4d(mm, __pa(p4d) >> PAGE_SHIFT);
 147         set_pgd_safe(pgd, __pgd(_PAGE_TABLE | __pa(p4d)));
 148 }
 149
 150 static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
 151 {
 152         gfp_t gfp = GFP_KERNEL_ACCOUNT;
 153
 154         if (mm == &init_mm)
 155                 gfp &= ~__GFP_ACCOUNT;
 156         return (p4d_t *)get_zeroed_page(gfp);
 157 }
 158
 159 static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
 160 {
 161         if (!pgtable_l5_enabled())
 162                 return;
 163
 164         BUG_ON((unsigned long)p4d & (PAGE_SIZE-1));
 165         free_page((unsigned long)p4d);
 166 }
 167
 168 extern void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d);
 169
 170 static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
 171                                   unsigned long address)
 172 {
 173         if (pgtable_l5_enabled())
 174                 ___p4d_free_tlb(tlb, p4d);
 175 }
 176
 177 #endif  /* CONFIG_PGTABLE_LEVELS > 4 */
 178 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
 179 #endif  /* CONFIG_PGTABLE_LEVELS > 2 */
 180
 181 #endif /* _ASM_X86_PGALLOC_H */