arch/loongarch/mm/pageattr.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2024 Loongson Technology Corporation Limited
   4  */
   5
   6 #include <linux/memblock.h>
   7 #include <linux/pagewalk.h>
   8 #include <linux/pgtable.h>
   9 #include <asm/set_memory.h>
  10 #include <asm/tlbflush.h>
  11
  12 struct pageattr_masks {
  13         pgprot_t set_mask;
  14         pgprot_t clear_mask;
  15 };
  16
  17 static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
  18 {
  19         unsigned long new_val = val;
  20         struct pageattr_masks *masks = walk->private;
  21
  22         new_val &= ~(pgprot_val(masks->clear_mask));
  23         new_val |= (pgprot_val(masks->set_mask));
  24
  25         return new_val;
  26 }
  27
  28 static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,
  29                               unsigned long next, struct mm_walk *walk)
  30 {
  31         pgd_t val = pgdp_get(pgd);
  32
  33         if (pgd_leaf(val)) {
  34                 val = __pgd(set_pageattr_masks(pgd_val(val), walk));
  35                 set_pgd(pgd, val);
  36         }
  37
  38         return 0;
  39 }
  40
  41 static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
  42                               unsigned long next, struct mm_walk *walk)
  43 {
  44         p4d_t val = p4dp_get(p4d);
  45
  46         if (p4d_leaf(val)) {
  47                 val = __p4d(set_pageattr_masks(p4d_val(val), walk));
  48                 set_p4d(p4d, val);
  49         }
  50
  51         return 0;
  52 }
  53
  54 static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
  55                               unsigned long next, struct mm_walk *walk)
  56 {
  57         pud_t val = pudp_get(pud);
  58
  59         if (pud_leaf(val)) {
  60                 val = __pud(set_pageattr_masks(pud_val(val), walk));
  61                 set_pud(pud, val);
  62         }
  63
  64         return 0;
  65 }
  66
  67 static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
  68                               unsigned long next, struct mm_walk *walk)
  69 {
  70         pmd_t val = pmdp_get(pmd);
  71
  72         if (pmd_leaf(val)) {
  73                 val = __pmd(set_pageattr_masks(pmd_val(val), walk));
  74                 set_pmd(pmd, val);
  75         }
  76
  77         return 0;
  78 }
  79
  80 static int pageattr_pte_entry(pte_t *pte, unsigned long addr,
  81                               unsigned long next, struct mm_walk *walk)
  82 {
  83         pte_t val = ptep_get(pte);
  84
  85         val = __pte(set_pageattr_masks(pte_val(val), walk));
  86         set_pte(pte, val);
  87
  88         return 0;
  89 }
  90
  91 static int pageattr_pte_hole(unsigned long addr, unsigned long next,
  92                              int depth, struct mm_walk *walk)
  93 {
  94         return 0;
  95 }
  96
  97 static const struct mm_walk_ops pageattr_ops = {
  98         .pgd_entry = pageattr_pgd_entry,
  99         .p4d_entry = pageattr_p4d_entry,
 100         .pud_entry = pageattr_pud_entry,
 101         .pmd_entry = pageattr_pmd_entry,
 102         .pte_entry = pageattr_pte_entry,
 103         .pte_hole = pageattr_pte_hole,
 104         .walk_lock = PGWALK_RDLOCK,
 105 };
 106
 107 static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask, pgprot_t clear_mask)
 108 {
 109         int ret;
 110         unsigned long start = addr;
 111         unsigned long end = start + PAGE_SIZE * numpages;
 112         struct pageattr_masks masks = {
 113                 .set_mask = set_mask,
 114                 .clear_mask = clear_mask
 115         };
 116
 117         if (!numpages)
 118                 return 0;
 119
 120         mmap_write_lock(&init_mm);
 121         ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL, &masks);
 122         mmap_write_unlock(&init_mm);
 123
 124         flush_tlb_kernel_range(start, end);
 125
 126         return ret;
 127 }
 128
 129 int set_memory_x(unsigned long addr, int numpages)
 130 {
 131         if (addr < vm_map_base)
 132                 return 0;
 133
 134         return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_NO_EXEC));
 135 }
 136
 137 int set_memory_nx(unsigned long addr, int numpages)
 138 {
 139         if (addr < vm_map_base)
 140                 return 0;
 141
 142         return __set_memory(addr, numpages, __pgprot(_PAGE_NO_EXEC), __pgprot(0));
 143 }
 144
 145 int set_memory_ro(unsigned long addr, int numpages)
 146 {
 147         if (addr < vm_map_base)
 148                 return 0;
 149
 150         return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_WRITE | _PAGE_DIRTY));
 151 }
 152
 153 int set_memory_rw(unsigned long addr, int numpages)
 154 {
 155         if (addr < vm_map_base)
 156                 return 0;
 157
 158         return __set_memory(addr, numpages, __pgprot(_PAGE_WRITE | _PAGE_DIRTY), __pgprot(0));
 159 }
 160
 161 bool kernel_page_present(struct page *page)
 162 {
 163         pgd_t *pgd;
 164         p4d_t *p4d;
 165         pud_t *pud;
 166         pmd_t *pmd;
 167         pte_t *pte;
 168         unsigned long addr = (unsigned long)page_address(page);
 169
 170         if (addr < vm_map_base)
 171                 return memblock_is_memory(__pa(addr));
 172
 173         pgd = pgd_offset_k(addr);
 174         if (pgd_none(pgdp_get(pgd)))
 175                 return false;
 176         if (pgd_leaf(pgdp_get(pgd)))
 177                 return true;
 178
 179         p4d = p4d_offset(pgd, addr);
 180         if (p4d_none(p4dp_get(p4d)))
 181                 return false;
 182         if (p4d_leaf(p4dp_get(p4d)))
 183                 return true;
 184
 185         pud = pud_offset(p4d, addr);
 186         if (pud_none(pudp_get(pud)))
 187                 return false;
 188         if (pud_leaf(pudp_get(pud)))
 189                 return true;
 190
 191         pmd = pmd_offset(pud, addr);
 192         if (pmd_none(pmdp_get(pmd)))
 193                 return false;
 194         if (pmd_leaf(pmdp_get(pmd)))
 195                 return true;
 196
 197         pte = pte_offset_kernel(pmd, addr);
 198         return pte_present(ptep_get(pte));
 199 }
 200
 201 int set_direct_map_default_noflush(struct page *page)
 202 {
 203         unsigned long addr = (unsigned long)page_address(page);
 204
 205         if (addr < vm_map_base)
 206                 return 0;
 207
 208         return __set_memory(addr, 1, PAGE_KERNEL, __pgprot(0));
 209 }
 210
 211 int set_direct_map_invalid_noflush(struct page *page)
 212 {
 213         unsigned long addr = (unsigned long)page_address(page);
 214
 215         if (addr < vm_map_base)
 216                 return 0;
 217
 218         return __set_memory(addr, 1, __pgprot(0), __pgprot(_PAGE_PRESENT | _PAGE_VALID));
 219 }
 220
 221 int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
 222 {
 223         unsigned long addr = (unsigned long)page_address(page);
 224         pgprot_t set, clear;
 225
 226         if (addr < vm_map_base)
 227                 return 0;
 228
 229         if (valid) {
 230                 set = PAGE_KERNEL;
 231                 clear = __pgprot(0);
 232         } else {
 233                 set = __pgprot(0);
 234                 clear = __pgprot(_PAGE_PRESENT | _PAGE_VALID);
 235         }
 236
 237         return __set_memory(addr, 1, set, clear);
 238 }