2 * Re-map IO memory to kernel address space so that we can access it.
3 * This is needed for high PCI addresses that aren't mapped in the
4 * 640k-1MB IO memory area on PC's
6 * (C) Copyright 1995 1996 Linus Torvalds
8 #include <linux/vmalloc.h>
10 #include <linux/sched.h>
12 #include <linux/export.h>
13 #include <asm/cacheflush.h>
14 #include <asm/pgtable.h>
16 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
17 static int __read_mostly ioremap_pud_capable;
18 static int __read_mostly ioremap_pmd_capable;
19 static int __read_mostly ioremap_huge_disabled;
21 static int __init set_nohugeiomap(char *str)
23 ioremap_huge_disabled = 1;
26 early_param("nohugeiomap", set_nohugeiomap);
28 void __init ioremap_huge_init(void)
30 if (!ioremap_huge_disabled) {
31 if (arch_ioremap_pud_supported())
32 ioremap_pud_capable = 1;
33 if (arch_ioremap_pmd_supported())
34 ioremap_pmd_capable = 1;
38 static inline int ioremap_pud_enabled(void)
40 return ioremap_pud_capable;
43 static inline int ioremap_pmd_enabled(void)
45 return ioremap_pmd_capable;
48 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
49 static inline int ioremap_pud_enabled(void) { return 0; }
50 static inline int ioremap_pmd_enabled(void) { return 0; }
51 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
53 static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
54 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
59 pfn = phys_addr >> PAGE_SHIFT;
60 pte = pte_alloc_kernel(pmd, addr);
64 BUG_ON(!pte_none(*pte));
65 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
67 } while (pte++, addr += PAGE_SIZE, addr != end);
71 static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
72 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
78 pmd = pmd_alloc(&init_mm, pud, addr);
82 next = pmd_addr_end(addr, end);
84 if (ioremap_pmd_enabled() &&
85 ((next - addr) == PMD_SIZE) &&
86 IS_ALIGNED(phys_addr + addr, PMD_SIZE)) {
87 if (pmd_set_huge(pmd, phys_addr + addr, prot))
91 if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
93 } while (pmd++, addr = next, addr != end);
97 static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
98 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
104 pud = pud_alloc(&init_mm, pgd, addr);
108 next = pud_addr_end(addr, end);
110 if (ioremap_pud_enabled() &&
111 ((next - addr) == PUD_SIZE) &&
112 IS_ALIGNED(phys_addr + addr, PUD_SIZE)) {
113 if (pud_set_huge(pud, phys_addr + addr, prot))
117 if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
119 } while (pud++, addr = next, addr != end);
123 int ioremap_page_range(unsigned long addr,
124 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
135 pgd = pgd_offset_k(addr);
137 next = pgd_addr_end(addr, end);
138 err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
141 } while (pgd++, addr = next, addr != end);
143 flush_cache_vmap(start, end);
147 EXPORT_SYMBOL_GPL(ioremap_page_range);