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_kernel_page_table_range(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 } 239