1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (C) 2019 SiFive 4 */ 5 6#include <linux/pagewalk.h> 7#include <linux/pgtable.h> 8#include <asm/tlbflush.h> 9#include <asm/bitops.h> 10#include <asm/set_memory.h> 11 12struct pageattr_masks { 13 pgprot_t set_mask; 14 pgprot_t clear_mask; 15}; 16 17static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk) 18{ 19 struct pageattr_masks *masks = walk->private; 20 unsigned long new_val = val; 21 22 new_val &= ~(pgprot_val(masks->clear_mask)); 23 new_val |= (pgprot_val(masks->set_mask)); 24 25 return new_val; 26} 27 28static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr, 29 unsigned long next, struct mm_walk *walk) 30{ 31 pgd_t val = READ_ONCE(*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 41static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr, 42 unsigned long next, struct mm_walk *walk) 43{ 44 p4d_t val = READ_ONCE(*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 54static int pageattr_pud_entry(pud_t *pud, unsigned long addr, 55 unsigned long next, struct mm_walk *walk) 56{ 57 pud_t val = READ_ONCE(*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 67static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr, 68 unsigned long next, struct mm_walk *walk) 69{ 70 pmd_t val = READ_ONCE(*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 80static int pageattr_pte_entry(pte_t *pte, unsigned long addr, 81 unsigned long next, struct mm_walk *walk) 82{ 83 pte_t val = READ_ONCE(*pte); 84 85 val = __pte(set_pageattr_masks(pte_val(val), walk)); 86 set_pte(pte, val); 87 88 return 0; 89} 90 91static int pageattr_pte_hole(unsigned long addr, unsigned long next, 92 int depth, struct mm_walk *walk) 93{ 94 /* Nothing to do here */ 95 return 0; 96} 97 98static const struct mm_walk_ops pageattr_ops = { 99 .pgd_entry = pageattr_pgd_entry, 100 .p4d_entry = pageattr_p4d_entry, 101 .pud_entry = pageattr_pud_entry, 102 .pmd_entry = pageattr_pmd_entry, 103 .pte_entry = pageattr_pte_entry, 104 .pte_hole = pageattr_pte_hole, 105}; 106 107static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask, 108 pgprot_t clear_mask) 109{ 110 int ret; 111 unsigned long start = addr; 112 unsigned long end = start + PAGE_SIZE * numpages; 113 struct pageattr_masks masks = { 114 .set_mask = set_mask, 115 .clear_mask = clear_mask 116 }; 117 118 if (!numpages) 119 return 0; 120 121 mmap_write_lock(&init_mm); 122 ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL, 123 &masks); 124 mmap_write_unlock(&init_mm); 125 126 flush_tlb_kernel_range(start, end); 127 128 return ret; 129} 130 131int set_memory_rw_nx(unsigned long addr, int numpages) 132{ 133 return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE), 134 __pgprot(_PAGE_EXEC)); 135} 136 137int set_memory_ro(unsigned long addr, int numpages) 138{ 139 return __set_memory(addr, numpages, __pgprot(_PAGE_READ), 140 __pgprot(_PAGE_WRITE)); 141} 142 143int set_memory_rw(unsigned long addr, int numpages) 144{ 145 return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE), 146 __pgprot(0)); 147} 148 149int set_memory_x(unsigned long addr, int numpages) 150{ 151 return __set_memory(addr, numpages, __pgprot(_PAGE_EXEC), __pgprot(0)); 152} 153 154int set_memory_nx(unsigned long addr, int numpages) 155{ 156 return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC)); 157} 158 159int set_direct_map_invalid_noflush(struct page *page) 160{ 161 int ret; 162 unsigned long start = (unsigned long)page_address(page); 163 unsigned long end = start + PAGE_SIZE; 164 struct pageattr_masks masks = { 165 .set_mask = __pgprot(0), 166 .clear_mask = __pgprot(_PAGE_PRESENT) 167 }; 168 169 mmap_read_lock(&init_mm); 170 ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks); 171 mmap_read_unlock(&init_mm); 172 173 return ret; 174} 175 176int set_direct_map_default_noflush(struct page *page) 177{ 178 int ret; 179 unsigned long start = (unsigned long)page_address(page); 180 unsigned long end = start + PAGE_SIZE; 181 struct pageattr_masks masks = { 182 .set_mask = PAGE_KERNEL, 183 .clear_mask = __pgprot(0) 184 }; 185 186 mmap_read_lock(&init_mm); 187 ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks); 188 mmap_read_unlock(&init_mm); 189 190 return ret; 191} 192 193void __kernel_map_pages(struct page *page, int numpages, int enable) 194{ 195 if (!debug_pagealloc_enabled()) 196 return; 197 198 if (enable) 199 __set_memory((unsigned long)page_address(page), numpages, 200 __pgprot(_PAGE_PRESENT), __pgprot(0)); 201 else 202 __set_memory((unsigned long)page_address(page), numpages, 203 __pgprot(0), __pgprot(_PAGE_PRESENT)); 204} 205