| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Re-map IO memory to kernel address space so that we can access it. |
| 4 | * This is needed for high PCI addresses that aren't mapped in the |
| 5 | * 640k-1MB IO memory area on PC's |
| 6 | * |
| 7 | * (C) Copyright 1995 1996 Linus Torvalds |
| 8 | */ |
| 9 | #include <linux/vmalloc.h> |
| 10 | #include <linux/mm.h> |
| 11 | #include <linux/sched.h> |
| 12 | #include <linux/io.h> |
| 13 | #include <linux/export.h> |
| 14 | #include <asm/cacheflush.h> |
| 15 | #include <asm/pgtable.h> |
| 16 | |
| 17 | #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP |
| 18 | static int __read_mostly ioremap_p4d_capable; |
| 19 | static int __read_mostly ioremap_pud_capable; |
| 20 | static int __read_mostly ioremap_pmd_capable; |
| 21 | static int __read_mostly ioremap_huge_disabled; |
| 22 | |
| 23 | static int __init set_nohugeiomap(char *str) |
| 24 | { |
| 25 | ioremap_huge_disabled = 1; |
| 26 | return 0; |
| 27 | } |
| 28 | early_param("nohugeiomap", set_nohugeiomap); |
| 29 | |
| 30 | void __init ioremap_huge_init(void) |
| 31 | { |
| 32 | if (!ioremap_huge_disabled) { |
| 33 | if (arch_ioremap_p4d_supported()) |
| 34 | ioremap_p4d_capable = 1; |
| 35 | if (arch_ioremap_pud_supported()) |
| 36 | ioremap_pud_capable = 1; |
| 37 | if (arch_ioremap_pmd_supported()) |
| 38 | ioremap_pmd_capable = 1; |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | static inline int ioremap_p4d_enabled(void) |
| 43 | { |
| 44 | return ioremap_p4d_capable; |
| 45 | } |
| 46 | |
| 47 | static inline int ioremap_pud_enabled(void) |
| 48 | { |
| 49 | return ioremap_pud_capable; |
| 50 | } |
| 51 | |
| 52 | static inline int ioremap_pmd_enabled(void) |
| 53 | { |
| 54 | return ioremap_pmd_capable; |
| 55 | } |
| 56 | |
| 57 | #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ |
| 58 | static inline int ioremap_p4d_enabled(void) { return 0; } |
| 59 | static inline int ioremap_pud_enabled(void) { return 0; } |
| 60 | static inline int ioremap_pmd_enabled(void) { return 0; } |
| 61 | #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ |
| 62 | |
| 63 | static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, |
| 64 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 65 | { |
| 66 | pte_t *pte; |
| 67 | u64 pfn; |
| 68 | |
| 69 | pfn = phys_addr >> PAGE_SHIFT; |
| 70 | pte = pte_alloc_kernel(pmd, addr); |
| 71 | if (!pte) |
| 72 | return -ENOMEM; |
| 73 | do { |
| 74 | BUG_ON(!pte_none(*pte)); |
| 75 | set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); |
| 76 | pfn++; |
| 77 | } while (pte++, addr += PAGE_SIZE, addr != end); |
| 78 | return 0; |
| 79 | } |
| 80 | |
| 81 | static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr, |
| 82 | unsigned long end, phys_addr_t phys_addr, |
| 83 | pgprot_t prot) |
| 84 | { |
| 85 | if (!ioremap_pmd_enabled()) |
| 86 | return 0; |
| 87 | |
| 88 | if ((end - addr) != PMD_SIZE) |
| 89 | return 0; |
| 90 | |
| 91 | if (!IS_ALIGNED(addr, PMD_SIZE)) |
| 92 | return 0; |
| 93 | |
| 94 | if (!IS_ALIGNED(phys_addr, PMD_SIZE)) |
| 95 | return 0; |
| 96 | |
| 97 | if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr)) |
| 98 | return 0; |
| 99 | |
| 100 | return pmd_set_huge(pmd, phys_addr, prot); |
| 101 | } |
| 102 | |
| 103 | static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr, |
| 104 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 105 | { |
| 106 | pmd_t *pmd; |
| 107 | unsigned long next; |
| 108 | |
| 109 | pmd = pmd_alloc(&init_mm, pud, addr); |
| 110 | if (!pmd) |
| 111 | return -ENOMEM; |
| 112 | do { |
| 113 | next = pmd_addr_end(addr, end); |
| 114 | |
| 115 | if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) |
| 116 | continue; |
| 117 | |
| 118 | if (ioremap_pte_range(pmd, addr, next, phys_addr, prot)) |
| 119 | return -ENOMEM; |
| 120 | } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); |
| 121 | return 0; |
| 122 | } |
| 123 | |
| 124 | static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr, |
| 125 | unsigned long end, phys_addr_t phys_addr, |
| 126 | pgprot_t prot) |
| 127 | { |
| 128 | if (!ioremap_pud_enabled()) |
| 129 | return 0; |
| 130 | |
| 131 | if ((end - addr) != PUD_SIZE) |
| 132 | return 0; |
| 133 | |
| 134 | if (!IS_ALIGNED(addr, PUD_SIZE)) |
| 135 | return 0; |
| 136 | |
| 137 | if (!IS_ALIGNED(phys_addr, PUD_SIZE)) |
| 138 | return 0; |
| 139 | |
| 140 | if (pud_present(*pud) && !pud_free_pmd_page(pud, addr)) |
| 141 | return 0; |
| 142 | |
| 143 | return pud_set_huge(pud, phys_addr, prot); |
| 144 | } |
| 145 | |
| 146 | static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr, |
| 147 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 148 | { |
| 149 | pud_t *pud; |
| 150 | unsigned long next; |
| 151 | |
| 152 | pud = pud_alloc(&init_mm, p4d, addr); |
| 153 | if (!pud) |
| 154 | return -ENOMEM; |
| 155 | do { |
| 156 | next = pud_addr_end(addr, end); |
| 157 | |
| 158 | if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) |
| 159 | continue; |
| 160 | |
| 161 | if (ioremap_pmd_range(pud, addr, next, phys_addr, prot)) |
| 162 | return -ENOMEM; |
| 163 | } while (pud++, phys_addr += (next - addr), addr = next, addr != end); |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr, |
| 168 | unsigned long end, phys_addr_t phys_addr, |
| 169 | pgprot_t prot) |
| 170 | { |
| 171 | if (!ioremap_p4d_enabled()) |
| 172 | return 0; |
| 173 | |
| 174 | if ((end - addr) != P4D_SIZE) |
| 175 | return 0; |
| 176 | |
| 177 | if (!IS_ALIGNED(addr, P4D_SIZE)) |
| 178 | return 0; |
| 179 | |
| 180 | if (!IS_ALIGNED(phys_addr, P4D_SIZE)) |
| 181 | return 0; |
| 182 | |
| 183 | if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr)) |
| 184 | return 0; |
| 185 | |
| 186 | return p4d_set_huge(p4d, phys_addr, prot); |
| 187 | } |
| 188 | |
| 189 | static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr, |
| 190 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 191 | { |
| 192 | p4d_t *p4d; |
| 193 | unsigned long next; |
| 194 | |
| 195 | p4d = p4d_alloc(&init_mm, pgd, addr); |
| 196 | if (!p4d) |
| 197 | return -ENOMEM; |
| 198 | do { |
| 199 | next = p4d_addr_end(addr, end); |
| 200 | |
| 201 | if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) |
| 202 | continue; |
| 203 | |
| 204 | if (ioremap_pud_range(p4d, addr, next, phys_addr, prot)) |
| 205 | return -ENOMEM; |
| 206 | } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | int ioremap_page_range(unsigned long addr, |
| 211 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 212 | { |
| 213 | pgd_t *pgd; |
| 214 | unsigned long start; |
| 215 | unsigned long next; |
| 216 | int err; |
| 217 | |
| 218 | might_sleep(); |
| 219 | BUG_ON(addr >= end); |
| 220 | |
| 221 | start = addr; |
| 222 | pgd = pgd_offset_k(addr); |
| 223 | do { |
| 224 | next = pgd_addr_end(addr, end); |
| 225 | err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot); |
| 226 | if (err) |
| 227 | break; |
| 228 | } while (pgd++, phys_addr += (next - addr), addr = next, addr != end); |
| 229 | |
| 230 | flush_cache_vmap(start, end); |
| 231 | |
| 232 | return err; |
| 233 | } |