ioremap.c 6.5 KB

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  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 "pgalloc-track.h"
  16. #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
  17. static int __read_mostly ioremap_p4d_capable;
  18. static int __read_mostly ioremap_pud_capable;
  19. static int __read_mostly ioremap_pmd_capable;
  20. static int __read_mostly ioremap_huge_disabled;
  21. static int __init set_nohugeiomap(char *str)
  22. {
  23. ioremap_huge_disabled = 1;
  24. return 0;
  25. }
  26. early_param("nohugeiomap", set_nohugeiomap);
  27. void __init ioremap_huge_init(void)
  28. {
  29. if (!ioremap_huge_disabled) {
  30. if (arch_ioremap_p4d_supported())
  31. ioremap_p4d_capable = 1;
  32. if (arch_ioremap_pud_supported())
  33. ioremap_pud_capable = 1;
  34. if (arch_ioremap_pmd_supported())
  35. ioremap_pmd_capable = 1;
  36. }
  37. }
  38. static inline int ioremap_p4d_enabled(void)
  39. {
  40. return ioremap_p4d_capable;
  41. }
  42. static inline int ioremap_pud_enabled(void)
  43. {
  44. return ioremap_pud_capable;
  45. }
  46. static inline int ioremap_pmd_enabled(void)
  47. {
  48. return ioremap_pmd_capable;
  49. }
  50. #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
  51. static inline int ioremap_p4d_enabled(void) { return 0; }
  52. static inline int ioremap_pud_enabled(void) { return 0; }
  53. static inline int ioremap_pmd_enabled(void) { return 0; }
  54. #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
  55. static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
  56. unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
  57. pgtbl_mod_mask *mask)
  58. {
  59. pte_t *pte;
  60. u64 pfn;
  61. pfn = phys_addr >> PAGE_SHIFT;
  62. pte = pte_alloc_kernel_track(pmd, addr, mask);
  63. if (!pte)
  64. return -ENOMEM;
  65. do {
  66. BUG_ON(!pte_none(*pte));
  67. set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
  68. pfn++;
  69. } while (pte++, addr += PAGE_SIZE, addr != end);
  70. *mask |= PGTBL_PTE_MODIFIED;
  71. return 0;
  72. }
  73. static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr,
  74. unsigned long end, phys_addr_t phys_addr,
  75. pgprot_t prot)
  76. {
  77. if (!ioremap_pmd_enabled())
  78. return 0;
  79. if ((end - addr) != PMD_SIZE)
  80. return 0;
  81. if (!IS_ALIGNED(addr, PMD_SIZE))
  82. return 0;
  83. if (!IS_ALIGNED(phys_addr, PMD_SIZE))
  84. return 0;
  85. if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
  86. return 0;
  87. return pmd_set_huge(pmd, phys_addr, prot);
  88. }
  89. static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
  90. unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
  91. pgtbl_mod_mask *mask)
  92. {
  93. pmd_t *pmd;
  94. unsigned long next;
  95. pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
  96. if (!pmd)
  97. return -ENOMEM;
  98. do {
  99. next = pmd_addr_end(addr, end);
  100. if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) {
  101. *mask |= PGTBL_PMD_MODIFIED;
  102. continue;
  103. }
  104. if (ioremap_pte_range(pmd, addr, next, phys_addr, prot, mask))
  105. return -ENOMEM;
  106. } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
  107. return 0;
  108. }
  109. static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr,
  110. unsigned long end, phys_addr_t phys_addr,
  111. pgprot_t prot)
  112. {
  113. if (!ioremap_pud_enabled())
  114. return 0;
  115. if ((end - addr) != PUD_SIZE)
  116. return 0;
  117. if (!IS_ALIGNED(addr, PUD_SIZE))
  118. return 0;
  119. if (!IS_ALIGNED(phys_addr, PUD_SIZE))
  120. return 0;
  121. if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
  122. return 0;
  123. return pud_set_huge(pud, phys_addr, prot);
  124. }
  125. static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
  126. unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
  127. pgtbl_mod_mask *mask)
  128. {
  129. pud_t *pud;
  130. unsigned long next;
  131. pud = pud_alloc_track(&init_mm, p4d, addr, mask);
  132. if (!pud)
  133. return -ENOMEM;
  134. do {
  135. next = pud_addr_end(addr, end);
  136. if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) {
  137. *mask |= PGTBL_PUD_MODIFIED;
  138. continue;
  139. }
  140. if (ioremap_pmd_range(pud, addr, next, phys_addr, prot, mask))
  141. return -ENOMEM;
  142. } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
  143. return 0;
  144. }
  145. static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
  146. unsigned long end, phys_addr_t phys_addr,
  147. pgprot_t prot)
  148. {
  149. if (!ioremap_p4d_enabled())
  150. return 0;
  151. if ((end - addr) != P4D_SIZE)
  152. return 0;
  153. if (!IS_ALIGNED(addr, P4D_SIZE))
  154. return 0;
  155. if (!IS_ALIGNED(phys_addr, P4D_SIZE))
  156. return 0;
  157. if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
  158. return 0;
  159. return p4d_set_huge(p4d, phys_addr, prot);
  160. }
  161. static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
  162. unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
  163. pgtbl_mod_mask *mask)
  164. {
  165. p4d_t *p4d;
  166. unsigned long next;
  167. p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
  168. if (!p4d)
  169. return -ENOMEM;
  170. do {
  171. next = p4d_addr_end(addr, end);
  172. if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) {
  173. *mask |= PGTBL_P4D_MODIFIED;
  174. continue;
  175. }
  176. if (ioremap_pud_range(p4d, addr, next, phys_addr, prot, mask))
  177. return -ENOMEM;
  178. } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
  179. return 0;
  180. }
  181. int ioremap_page_range(unsigned long addr,
  182. unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
  183. {
  184. pgd_t *pgd;
  185. unsigned long start;
  186. unsigned long next;
  187. int err;
  188. pgtbl_mod_mask mask = 0;
  189. might_sleep();
  190. BUG_ON(addr >= end);
  191. start = addr;
  192. pgd = pgd_offset_k(addr);
  193. do {
  194. next = pgd_addr_end(addr, end);
  195. err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot,
  196. &mask);
  197. if (err)
  198. break;
  199. } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
  200. flush_cache_vmap(start, end);
  201. if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
  202. arch_sync_kernel_mappings(start, end);
  203. return err;
  204. }
  205. #ifdef CONFIG_GENERIC_IOREMAP
  206. void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot)
  207. {
  208. unsigned long offset, vaddr;
  209. phys_addr_t last_addr;
  210. struct vm_struct *area;
  211. /* Disallow wrap-around or zero size */
  212. last_addr = addr + size - 1;
  213. if (!size || last_addr < addr)
  214. return NULL;
  215. /* Page-align mappings */
  216. offset = addr & (~PAGE_MASK);
  217. addr -= offset;
  218. size = PAGE_ALIGN(size + offset);
  219. area = get_vm_area_caller(size, VM_IOREMAP,
  220. __builtin_return_address(0));
  221. if (!area)
  222. return NULL;
  223. vaddr = (unsigned long)area->addr;
  224. if (ioremap_page_range(vaddr, vaddr + size, addr, __pgprot(prot))) {
  225. free_vm_area(area);
  226. return NULL;
  227. }
  228. return (void __iomem *)(vaddr + offset);
  229. }
  230. EXPORT_SYMBOL(ioremap_prot);
  231. void iounmap(volatile void __iomem *addr)
  232. {
  233. vunmap((void *)((unsigned long)addr & PAGE_MASK));
  234. }
  235. EXPORT_SYMBOL(iounmap);
  236. #endif /* CONFIG_GENERIC_IOREMAP */