arch/loongarch/mm/pgtable.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
   4  */
   5 #include <linux/init.h>
   6 #include <linux/export.h>
   7 #include <linux/mm.h>
   8 #include <asm/pgalloc.h>
   9 #include <asm/pgtable.h>
  10 #include <asm/tlbflush.h>
  11
  12 pgd_t *pgd_alloc(struct mm_struct *mm)
  13 {
  14         pgd_t *ret, *init;
  15
  16         ret = (pgd_t *) __get_free_page(GFP_KERNEL);
  17         if (ret) {
  18                 init = pgd_offset(&init_mm, 0UL);
  19                 pgd_init(ret);
  20                 memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
  21                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
  22         }
  23
  24         return ret;
  25 }
  26 EXPORT_SYMBOL_GPL(pgd_alloc);
  27
  28 void pgd_init(void *addr)
  29 {
  30         unsigned long *p, *end;
  31         unsigned long entry;
  32
  33 #if !defined(__PAGETABLE_PUD_FOLDED)
  34         entry = (unsigned long)invalid_pud_table;
  35 #elif !defined(__PAGETABLE_PMD_FOLDED)
  36         entry = (unsigned long)invalid_pmd_table;
  37 #else
  38         entry = (unsigned long)invalid_pte_table;
  39 #endif
  40
  41         p = (unsigned long *)addr;
  42         end = p + PTRS_PER_PGD;
  43
  44         do {
  45                 p[0] = entry;
  46                 p[1] = entry;
  47                 p[2] = entry;
  48                 p[3] = entry;
  49                 p[4] = entry;
  50                 p += 8;
  51                 p[-3] = entry;
  52                 p[-2] = entry;
  53                 p[-1] = entry;
  54         } while (p != end);
  55 }
  56 EXPORT_SYMBOL_GPL(pgd_init);
  57
  58 #ifndef __PAGETABLE_PMD_FOLDED
  59 void pmd_init(void *addr)
  60 {
  61         unsigned long *p, *end;
  62         unsigned long pagetable = (unsigned long)invalid_pte_table;
  63
  64         p = (unsigned long *)addr;
  65         end = p + PTRS_PER_PMD;
  66
  67         do {
  68                 p[0] = pagetable;
  69                 p[1] = pagetable;
  70                 p[2] = pagetable;
  71                 p[3] = pagetable;
  72                 p[4] = pagetable;
  73                 p += 8;
  74                 p[-3] = pagetable;
  75                 p[-2] = pagetable;
  76                 p[-1] = pagetable;
  77         } while (p != end);
  78 }
  79 EXPORT_SYMBOL_GPL(pmd_init);
  80 #endif
  81
  82 #ifndef __PAGETABLE_PUD_FOLDED
  83 void pud_init(void *addr)
  84 {
  85         unsigned long *p, *end;
  86         unsigned long pagetable = (unsigned long)invalid_pmd_table;
  87
  88         p = (unsigned long *)addr;
  89         end = p + PTRS_PER_PUD;
  90
  91         do {
  92                 p[0] = pagetable;
  93                 p[1] = pagetable;
  94                 p[2] = pagetable;
  95                 p[3] = pagetable;
  96                 p[4] = pagetable;
  97                 p += 8;
  98                 p[-3] = pagetable;
  99                 p[-2] = pagetable;
 100                 p[-1] = pagetable;
 101         } while (p != end);
 102 }
 103 EXPORT_SYMBOL_GPL(pud_init);
 104 #endif
 105
 106 pmd_t mk_pmd(struct page *page, pgprot_t prot)
 107 {
 108         pmd_t pmd;
 109
 110         pmd_val(pmd) = (page_to_pfn(page) << _PFN_SHIFT) | pgprot_val(prot);
 111
 112         return pmd;
 113 }
 114
 115 void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 116                 pmd_t *pmdp, pmd_t pmd)
 117 {
 118         *pmdp = pmd;
 119         flush_tlb_all();
 120 }
 121
 122 void __init pagetable_init(void)
 123 {
 124         /* Initialize the entire pgd.  */
 125         pgd_init(swapper_pg_dir);
 126         pgd_init(invalid_pg_dir);
 127 #ifndef __PAGETABLE_PUD_FOLDED
 128         pud_init(invalid_pud_table);
 129 #endif
 130 #ifndef __PAGETABLE_PMD_FOLDED
 131         pmd_init(invalid_pmd_table);
 132 #endif
 133 }