1 // SPDX-License-Identifier: GPL-2.0
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
7 * (C) Copyright 1995 1996 Linus Torvalds
9 #include <linux/vmalloc.h>
11 #include <linux/sched.h>
13 #include <linux/export.h>
14 #include <asm/cacheflush.h>
15 #include <asm/pgtable.h>
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;
23 static int __init set_nohugeiomap(char *str)
25 ioremap_huge_disabled = 1;
28 early_param("nohugeiomap", set_nohugeiomap);
30 void __init ioremap_huge_init(void)
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;
42 static inline int ioremap_p4d_enabled(void)
44 return ioremap_p4d_capable;
47 static inline int ioremap_pud_enabled(void)
49 return ioremap_pud_capable;
52 static inline int ioremap_pmd_enabled(void)
54 return ioremap_pmd_capable;
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 */
63 static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
64 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
70 pfn = phys_addr >> PAGE_SHIFT;
71 pte = pte_alloc_kernel_track(pmd, addr, mask);
75 BUG_ON(!pte_none(*pte));
76 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
78 } while (pte++, addr += PAGE_SIZE, addr != end);
79 *mask |= PGTBL_PTE_MODIFIED;
83 static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr,
84 unsigned long end, phys_addr_t phys_addr,
87 if (!ioremap_pmd_enabled())
90 if ((end - addr) != PMD_SIZE)
93 if (!IS_ALIGNED(addr, PMD_SIZE))
96 if (!IS_ALIGNED(phys_addr, PMD_SIZE))
99 if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
102 return pmd_set_huge(pmd, phys_addr, prot);
105 static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
106 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
107 pgtbl_mod_mask *mask)
112 pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
116 next = pmd_addr_end(addr, end);
118 if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) {
119 *mask |= PGTBL_PMD_MODIFIED;
123 if (ioremap_pte_range(pmd, addr, next, phys_addr, prot, mask))
125 } while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
129 static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr,
130 unsigned long end, phys_addr_t phys_addr,
133 if (!ioremap_pud_enabled())
136 if ((end - addr) != PUD_SIZE)
139 if (!IS_ALIGNED(addr, PUD_SIZE))
142 if (!IS_ALIGNED(phys_addr, PUD_SIZE))
145 if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
148 return pud_set_huge(pud, phys_addr, prot);
151 static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
152 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
153 pgtbl_mod_mask *mask)
158 pud = pud_alloc_track(&init_mm, p4d, addr, mask);
162 next = pud_addr_end(addr, end);
164 if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) {
165 *mask |= PGTBL_PUD_MODIFIED;
169 if (ioremap_pmd_range(pud, addr, next, phys_addr, prot, mask))
171 } while (pud++, phys_addr += (next - addr), addr = next, addr != end);
175 static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
176 unsigned long end, phys_addr_t phys_addr,
179 if (!ioremap_p4d_enabled())
182 if ((end - addr) != P4D_SIZE)
185 if (!IS_ALIGNED(addr, P4D_SIZE))
188 if (!IS_ALIGNED(phys_addr, P4D_SIZE))
191 if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
194 return p4d_set_huge(p4d, phys_addr, prot);
197 static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
198 unsigned long end, phys_addr_t phys_addr, pgprot_t prot,
199 pgtbl_mod_mask *mask)
204 p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
208 next = p4d_addr_end(addr, end);
210 if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) {
211 *mask |= PGTBL_P4D_MODIFIED;
215 if (ioremap_pud_range(p4d, addr, next, phys_addr, prot, mask))
217 } while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
221 int ioremap_page_range(unsigned long addr,
222 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
228 pgtbl_mod_mask mask = 0;
234 pgd = pgd_offset_k(addr);
236 next = pgd_addr_end(addr, end);
237 err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot,
241 } while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
243 flush_cache_vmap(start, end);
245 if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
246 arch_sync_kernel_mappings(start, end);
251 #ifdef CONFIG_GENERIC_IOREMAP
252 void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot)
254 unsigned long offset, vaddr;
255 phys_addr_t last_addr;
256 struct vm_struct *area;
258 /* Disallow wrap-around or zero size */
259 last_addr = addr + size - 1;
260 if (!size || last_addr < addr)
263 /* Page-align mappings */
264 offset = addr & (~PAGE_MASK);
266 size = PAGE_ALIGN(size + offset);
268 area = get_vm_area_caller(size, VM_IOREMAP,
269 __builtin_return_address(0));
272 vaddr = (unsigned long)area->addr;
274 if (ioremap_page_range(vaddr, vaddr + size, addr, __pgprot(prot))) {
279 return (void __iomem *)(vaddr + offset);
281 EXPORT_SYMBOL(ioremap_prot);
283 void iounmap(volatile void __iomem *addr)
285 vunmap((void *)((unsigned long)addr & PAGE_MASK));
287 EXPORT_SYMBOL(iounmap);
288 #endif /* CONFIG_GENERIC_IOREMAP */