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 *init, *ret = NULL;
  15         struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
  16
  17         if (ptdesc) {
  18                 ret = (pgd_t *)ptdesc_address(ptdesc);
  19                 init = pgd_offset(&init_mm, 0UL);
  20                 pgd_init(ret);
  21                 memcpy(ret + USER_PTRS_PER_PGD, init + USER_PTRS_PER_PGD,
  22                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
  23         }
  24
  25         return ret;
  26 }
  27 EXPORT_SYMBOL_GPL(pgd_alloc);
  28
  29 void pgd_init(void *addr)
  30 {
  31         unsigned long *p, *end;
  32         unsigned long entry;
  33
  34 #if !defined(__PAGETABLE_PUD_FOLDED)
  35         entry = (unsigned long)invalid_pud_table;
  36 #elif !defined(__PAGETABLE_PMD_FOLDED)
  37         entry = (unsigned long)invalid_pmd_table;
  38 #else
  39         entry = (unsigned long)invalid_pte_table;
  40 #endif
  41
  42         p = (unsigned long *)addr;
  43         end = p + PTRS_PER_PGD;
  44
  45         do {
  46                 p[0] = entry;
  47                 p[1] = entry;
  48                 p[2] = entry;
  49                 p[3] = entry;
  50                 p[4] = entry;
  51                 p += 8;
  52                 p[-3] = entry;
  53                 p[-2] = entry;
  54                 p[-1] = entry;
  55         } while (p != end);
  56 }
  57 EXPORT_SYMBOL_GPL(pgd_init);
  58
  59 #ifndef __PAGETABLE_PMD_FOLDED
  60 void pmd_init(void *addr)
  61 {
  62         unsigned long *p, *end;
  63         unsigned long pagetable = (unsigned long)invalid_pte_table;
  64
  65         p = (unsigned long *)addr;
  66         end = p + PTRS_PER_PMD;
  67
  68         do {
  69                 p[0] = pagetable;
  70                 p[1] = pagetable;
  71                 p[2] = pagetable;
  72                 p[3] = pagetable;
  73                 p[4] = pagetable;
  74                 p += 8;
  75                 p[-3] = pagetable;
  76                 p[-2] = pagetable;
  77                 p[-1] = pagetable;
  78         } while (p != end);
  79 }
  80 EXPORT_SYMBOL_GPL(pmd_init);
  81 #endif
  82
  83 #ifndef __PAGETABLE_PUD_FOLDED
  84 void pud_init(void *addr)
  85 {
  86         unsigned long *p, *end;
  87         unsigned long pagetable = (unsigned long)invalid_pmd_table;
  88
  89         p = (unsigned long *)addr;
  90         end = p + PTRS_PER_PUD;
  91
  92         do {
  93                 p[0] = pagetable;
  94                 p[1] = pagetable;
  95                 p[2] = pagetable;
  96                 p[3] = pagetable;
  97                 p[4] = pagetable;
  98                 p += 8;
  99                 p[-3] = pagetable;
 100                 p[-2] = pagetable;
 101                 p[-1] = pagetable;
 102         } while (p != end);
 103 }
 104 EXPORT_SYMBOL_GPL(pud_init);
 105 #endif
 106
 107 pmd_t mk_pmd(struct page *page, pgprot_t prot)
 108 {
 109         pmd_t pmd;
 110
 111         pmd_val(pmd) = (page_to_pfn(page) << PFN_PTE_SHIFT) | pgprot_val(prot);
 112
 113         return pmd;
 114 }
 115
 116 void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 117                 pmd_t *pmdp, pmd_t pmd)
 118 {
 119         *pmdp = pmd;
 120         flush_tlb_all();
 121 }
 122
 123 void __init pagetable_init(void)
 124 {
 125         /* Initialize the entire pgd.  */
 126         pgd_init(swapper_pg_dir);
 127         pgd_init(invalid_pg_dir);
 128 #ifndef __PAGETABLE_PUD_FOLDED
 129         pud_init(invalid_pud_table);
 130 #endif
 131 #ifndef __PAGETABLE_PMD_FOLDED
 132         pmd_init(invalid_pmd_table);
 133 #endif
 134 }